Absorption Refrigeration Cycles with Ammonia–Ionic Liquid Working Pairs Studied by Molecular Simulation

PubMed Central

2018-01-01

For absorption refrigeration, it has been shown that ionic liquids have the potential to replace conventional working pairs. Due to the huge number of possibilities, conducting lab experiments to find the optimal ionic liquid is infeasible. Here, we provide a proof-of-principle study of an alternative computational approach. The required thermodynamic properties, i.e., solubility, heat capacity, and heat of absorption, are determined via molecular simulations. These properties are used in a model of the absorption refrigeration cycle to estimate the circulation ratio and the coefficient of performance. We selected two ionic liquids as absorbents: [emim][Tf2N], and [emim][SCN]. As refrigerant NH3 was chosen due to its favorable operating range. The results are compared to the traditional approach in which parameters of a thermodynamic model are fitted to reproduce experimental data. The work shows that simulations can be used to predict the required thermodynamic properties to estimate the performance of absorption refrigeration cycles. However, high-quality force fields are required to accurately predict the cycle performance. PMID:29749996

An experimental study of the flow of LPG as refrigerant inside an adiabatic helical coiled capillary tube in vapour compression refrigeration system

NASA Astrophysics Data System (ADS)

Punia, Sanjeev Singh; Singh, Jagdev

2015-11-01

This paper presents an experimental investigation for the flow of liquefied petroleum gas (LPG) as a refrigerant inside an adiabatic helically coiled capillary tube in vapour compression refrigeration system. The effect of various geometric parameters and operating conditions like capillary tube inner diameter, length of capillary tube, coil diameter and different inlet subcoolings on the mass flow rate of LPG through the helical coiled capillary tube geometry has been investigated. It has been established that the coil diameter significantly influences the mass flow rate of LPG through the adiabatic helical capillary tube. It has been concluded that the effect of coiling of capillary tube reduces the mass flow rate by 5-12 % as compared to those of the straight capillary tube operating under similar conditions. The data obtained from the experiments are analyzed and a dimensionless correlation has been developed. The proposed correlation predicts that more than 90 % of experimental data which is in agreement with measured data in an error band of ±10 %.

Measurement of absorption rates of HFC single and blended refrigerants in POE oils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leung, M.; Jotshi, C.K.; Goswami, D.Y.

1999-07-01

Thermophysical properties of refrigerant/lubricant mixtures play an important role in refrigeration and air-conditioning system design. Therefore it is important to have a good understanding of the mixture composition in each system component such as the compressor or evaporator. Because the system operation is dynamic the rates of absorption and desorption become significant parameters. In this paper measured absorption rates of alternative refrigerants in polyolester (POE) oils are reported. An effective online mass gain method was designed and constructed to measure the absorption rates and solubility of refrigerants in lubricants. HFC single refrigerants (R-32, R-125, R-134a, and R-143a), and blended refrigerantsmore » (R-404A, R-407C, and R-410A) were tested with POE ISO 68 lubricant under various conditions. The experimental results showed that, at room temperature, R-134a is the most soluble in POE ISO 68 oil among all the refrigerants tested at pressures of 239 kPa (20 psig) to 446 kPa (70 psig). Among the blended refrigerants tested, R-407C was found to be the most soluble at room temperature and pressures of 239 kPa and 446 kPa. Experimental solubility data from this new measurement method were compared with data available in the literature. Good agreement between the two indicates the feasibility of the new method employed in this investigation.« less

Qubit absorption refrigerator at strong coupling

NASA Astrophysics Data System (ADS)

Mu, Anqi; Agarwalla, Bijay Kumar; Schaller, Gernot; Segal, Dvira

2017-12-01

We demonstrate that a quantum absorption refrigerator (QAR) can be realized from the smallest quantum system, a qubit, by coupling it in a non-additive (strong) manner to three heat baths. This function is un-attainable for the qubit model under the weak system-bath coupling limit, when the dissipation is additive. In an optimal design, the reservoirs are engineered and characterized by a single frequency component. We then obtain closed expressions for the cooling window and refrigeration efficiency, as well as bounds for the maximal cooling efficiency and the efficiency at maximal power. Our results agree with macroscopic designs and with three-level models for QARs, which are based on the weak system-bath coupling assumption. Beyond the optimal limit, we show with analytical calculations and numerical simulations that the cooling efficiency varies in a non-universal manner with model parameters. Our work demonstrates that strongly-coupled quantum machines can exhibit function that is un-attainable under the weak system-bath coupling assumption.

Triple loop heat exchanger for an absorption refrigeration system

DOEpatents

Reimann, Robert C.

1984-01-01

A triple loop heat exchanger for an absorption refrigeration system is disclosed. The triple loop heat exchanger comprises portions of a strong solution line for conducting relatively hot, strong solution from a generator to a solution heat exchanger of the absorption refrigeration system, conduit means for conducting relatively cool, weak solution from the solution heat exchanger to the generator, and a bypass system for conducting strong solution from the generator around the strong solution line and around the solution heat exchanger to an absorber of the refrigeration system when strong solution builds up in the generator to an undesirable level. The strong solution line and the conduit means are in heat exchange relationship with each other in the triple loop heat exchanger so that, during normal operation of the refrigeration system, heat is exchanged between the relatively hot, strong solution flowing through the strong solution line and the relatively cool, weak solution flowing through the conduit means. Also, the strong solution line and the bypass system are in heat exchange relationship in the triple loop heat exchanger so that if the normal flow path of relatively hot, strong solution flowing from the generator to an absorber is blocked, then this relatively, hot strong solution which will then be flowing through the bypass system in the triple loop heat exchanger, is brought into heat exchange relationship with any strong solution which may have solidified in the strong solution line in the triple loop heat exchanger to thereby aid in desolidifying any such solidified strong solution.

Water vapour foreign-continuum absorption in near-infrared windows from laboratory measurements.

PubMed

Ptashnik, Igor V; McPheat, Robert A; Shine, Keith P; Smith, Kevin M; Williams, R Gary

2012-06-13

For a long time, it has been believed that atmospheric absorption of radiation within wavelength regions of relatively high infrared transmittance (so-called 'windows') was dominated by the water vapour self-continuum, that is, spectrally smooth absorption caused by H(2)O--H(2)O pair interaction. Absorption due to the foreign continuum (i.e. caused mostly by H(2)O--N(2) bimolecular absorption in the Earth's atmosphere) was considered to be negligible in the windows. We report new retrievals of the water vapour foreign continuum from high-resolution laboratory measurements at temperatures between 350 and 430 K in four near-infrared windows between 1.1 and 5 μm (9000-2000 cm(-1)). Our results indicate that the foreign continuum in these windows has a very weak temperature dependence and is typically between one and two orders of magnitude stronger than that given in representations of the continuum currently used in many climate and weather prediction models. This indicates that absorption owing to the foreign continuum may be comparable to the self-continuum under atmospheric conditions in the investigated windows. The calculated global-average clear-sky atmospheric absorption of solar radiation is increased by approximately 0.46 W m(-2) (or 0.6% of the total clear-sky absorption) by using these new measurements when compared with calculations applying the widely used MTCKD (Mlawer-Tobin-Clough-Kneizys-Davies) foreign-continuum model.

Nonequilibrium quantum absorption refrigerator

NASA Astrophysics Data System (ADS)

Du, Jian-Ying; Zhang, Fu-Lin

2018-06-01

We study a quantum absorption refrigerator, in which a target qubit is cooled by two machine qubits in a nonequilibrium steady-state. It is realized by a strong internal coupling in the two-qubit fridge and a vanishing tripartite interaction among the whole system. The coherence of a machine virtual qubit is investigated as quantumness of the fridge. A necessary condition for cooling shows that the quantum coherence is beneficial to the nonequilibrium fridge, while it is detrimental as far as the maximum coefficient of performance (COP) and the COP at maximum power are concerned. Here, the COP is defined only in terms of heat currents caused by the tripartite interaction, with the one maintaining the two-qubit nonequilibrium state being excluded. The later can be considered to have no direct involvement in extracting heat from the target, as it is not affected by the tripartite interaction.

Waste heat driven absorption refrigeration process and system

DOEpatents

Wilkinson, William H.

1982-01-01

Absorption cycle refrigeration processes and systems are provided which are driven by the sensible waste heat available from industrial processes and other sources. Systems are disclosed which provide a chilled water output which can be used for comfort conditioning or the like which utilize heat from sensible waste heat sources at temperatures of less than 170.degree. F. Countercurrent flow equipment is also provided to increase the efficiency of the systems and increase the utilization of available heat.

Membrane-Based Absorption Refrigeration Systems: Nanoengineered Membrane-Based Absorption Cooling for Buildings Using Unconcentrated Solar & Waste Heat

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

BEETIT Project: UFL is improving a refrigeration system that uses low quality heat to provide the energy needed to drive cooling. This system, known as absorption refrigeration system (ARS), typically consists of large coils that transfer heat. Unfortunately, these large heat exchanger coils are responsible for bulkiness and high cost of ARS. UFL is using new materials as well as system design innovations to develop nanoengineered membranes to allow for enhanced heat exchange that reduces bulkiness. UFL’s design allows for compact, cheaper and more reliable use of ARS that use solar or waste heat.

Measurements of spectral parameters of water-vapour transitions near 1388 and 1345 nm for accurate simulation of high-pressure absorption spectra

NASA Astrophysics Data System (ADS)

Liu, Xiang; Jeffries, Jay B.; Hanson, Ronald K.

2007-05-01

Quantitative near-infrared absorption spectroscopy of water-vapour overtone and combination bands at high pressures is complicated by pressure broadening and shifting of individual lines and the blending of neighbouring transitions. An experimental and computational methodology is developed to determine accurate high-pressure absorption spectra. This case study investigates two water-vapour transitions, one near 1388 nm (7203.9 cm-1) and the other near 1345 nm (7435.6 cm-1), for potential two-line absorption measurements of temperature in the range of 400-1050 K with a pressure varying from 5-25 atm. The required quantitative spectroscopy data (line strength, collisional broadening, and pressure-induced frequency shift) of the target transitions and their neighbours (a total of four H2O vapour transitions near 1388 nm and six transitions near 1345 nm) are measured in neat H2O vapour, H2O-air and H2O-CO2 mixtures as a function of temperature (296-1000 K) at low pressures (<800 Torr). Precise values of the line strength S(T), pressure-broadening coefficients γair(T) and \\gamma _{CO_2 } (T), and pressure-shift coefficients δair(T) and \\delta _{CO_2 } (T) for the ten transitions were inferred from the measured spectra and compared with data from HITRAN 2004. A hybrid spectroscopic database was constructed by modifying HITRAN 2004 to incorporate these values for simulation of water-vapour-absorption spectra at high pressures. Simulations using this hybrid database are in good agreement with high pressure experiments and demonstrate that data collected at modest pressures can be used to simulate high-pressure absorption spectra.

Intermittent Solar Ammonia Absorption Cycle (ISAAC) refrigeration for lesser developed countries

NASA Astrophysics Data System (ADS)

Erickson, Donald C.

1990-02-01

The Intermittent Solar Ammonia Absorption Cycle (ISAAC) refrigerator is a solar thermal technology which provides low cost, efficient, reliable ice-making to areas without ready access to electricity. An ISAAC refrigeration system consists of a compound parabolic solar collector, two pressure vessels, a condenser, a cold box or refrigerated space, and simple connective piping -- no moving parts or electrical components. Most parts are simple construction or plumbing grade materials, locally available in many remote areas. This technology has numerous potential benefits in lesser developed countries both by providing a cheap, reliable source of ice, and, since manufacture requires only semi-skilled labor, a source of employment to the local economy. Applications include vaccine storage for health care clinics; fish, meat, and dairy product storage; and personal consumption. Importantly, this technology increases the quality of life for people in lesser developed countries without depleting fossil fuel resources or increasing the release of greenhouse gases such as CO2 and chlorofluorocarbons.

Spray generators for absorption refrigeration systems

DOEpatents

Sibley, Howard W.

1979-06-19

A spray generator for an absorption refrigeration system that includes a heat exchanger comprised of a multiplicity of variably spaced heat exchange tubes. The tubes are spaced close together near the top of the heat exchanger and spaced more widely apart near the bottom of the heat exchanger. Dilute absorbent solution is sprayed down through the heat exchanger. The close nesting of the tubes in the top portion of the heat exchanger retards liquid flow and aids heating of the solution. The wide spacing of the tubes in the lower section of the heat exchanger facilitate vapor flow out of the heat exchanger and eliminates liquid "blow-off". The top tubes are covered by a baffle to prevent the liquid solution from splashing out of the heat exchanger off of these top tubes.

Computational Evaluation of Mixtures of Hydrofluorocarbons and Deep Eutectic Solvents for Absorption Refrigeration Systems.

PubMed

Abedin, Rubaiyet; Heidarian, Sharareh; Flake, John C; Hung, Francisco R

2017-10-24

We used computational tools to evaluate three working fluid mixtures for single-effect absorption refrigeration systems, where the generator (desorber) is powered by waste or solar heat. The mixtures studied here resulted from combining a widely used hydrofluorocarbon (HFC) refrigerant, R134a, with three common deep eutectic solvents (DESs) formed by mixing choline chloride (hydrogen bond acceptor, HBA) with urea, glycerol, or ethylene glycol as the hydrogen bond donor (HBD) species. The COSMOtherm/TmoleX software package was used in combination with refrigerant data from NIST/REFPROP, to perform a thermodynamic evaluation of absorption refrigeration cycles using the proposed working fluid mixtures. Afterward, classical MD simulations of the three mixtures were performed to gain insight on these systems at the molecular level. Larger cycle efficiencies are obtained when R134a is combined with choline chloride and ethylene glycol, followed by the system where glycerol is the HBD, and finally that where the HBD is urea. MD simulations indicate that the local density profiles of all species exhibit very sharp variations in systems containing glycerol or urea; furthermore, the Henry's law constants of R134a in these two systems are larger than those observed for the HFC in choline chloride and ethylene glycol, indicating that R134a is more soluble in the latter DES. Interaction energies indicate that the R134a-R134a interactions are weaker in the system where ethylene glycol is the HBD, as compared to in the other DES. Radial distribution functions confirm that in all systems, the DES species do not form strong directional interactions (e.g., hydrogen bonds) with the R134a molecules. Relatively strong interactions are observed between the Cl anions and the hydrogen atoms in R134a; however, the atom-atom interactions between R134a and the cation and HBD species are weaker and do not play a significant role in the solvation of the refrigerant. In all systems, R134a has

Functional Dependence of Thermodynamic and Thermokinetic Parameters of Refrigerants Used in Mine Air Refrigerators. Part 1 - Refrigerant R407C

NASA Astrophysics Data System (ADS)

Nowak, Bernard; Życzkowski, Piotr; Łuczak, Rafał

2017-03-01

The authors of this article dealt with the issue of modeling the thermodynamic and thermokinetic properties (parameters) of refrigerants. The knowledge of these parameters is essential to design refrigeration equipment, to perform their energy efficiency analysis, or to compare the efficiency of air refrigerators using different refrigerants. One of the refrigerants used in mine air compression refrigerators is R407C. For this refrigerant, 23 dependencies were developed, determining its thermodynamic and thermokinetic parameters in the states of saturated liquid, dry saturated vapour, superheated vapor, subcooled liquid, and in the two-phase region. The created formulas have been presented in Tables 2, 5, 8, 10 and 12, respectively. It should be noted that the scope of application of these formulas is wider than the range of changes of that refrigerant during the normal operation of mine refrigeration equipment. The article ends with the statistical verification of the developed dependencies. For this purpose, for each model correlation coefficients and coefficients of determination were calculated, as well as absolute and relative deviations between the given values from the program REFPROP 7 (Lemmon et al., 2002) and the calculated ones. The results of these calculations have been contained in Tables 14 and 15.

Absolute high spectral resolution measurements of surface solar radiation for detection of water vapour continuum absorption.

PubMed

Gardiner, T D; Coleman, M; Browning, H; Tallis, L; Ptashnik, I V; Shine, K P

2012-06-13

Solar-pointing Fourier transform infrared (FTIR) spectroscopy offers the capability to measure both the fine scale and broadband spectral structure of atmospheric transmission simultaneously across wide spectral regions. It is therefore suited to the study of both water vapour monomer and continuum absorption behaviours. However, in order to properly address this issue, it is necessary to radiatively calibrate the FTIR instrument response. A solar-pointing high-resolution FTIR spectrometer was deployed as part of the 'Continuum Absorption by Visible and Infrared radiation and its Atmospheric Relevance' (CAVIAR) consortium project. This paper describes the radiative calibration process using an ultra-high-temperature blackbody and the consideration of the related influence factors. The result is a radiatively calibrated measurement of the solar irradiation at the ground across the IR region from 2000 to 10 000 cm(-1) with an uncertainty of between 3.3 and 5.9 per cent. This measurement is shown to be in good general agreement with a radiative-transfer model. The results from the CAVIAR field measurements are being used in ongoing studies of atmospheric absorbers, in particular the water vapour continuum.

Experimental study of refrigeration performance based on linear Fresnel solar thermal photovoltaic system

NASA Astrophysics Data System (ADS)

Song, Jinghui; Yuan, Hui; Xia, Yunfeng; Kan, Weimin; Deng, Xiaowen; Liu, Shi; Liang, Wanlong; Deng, Jianhua

2018-03-01

This paper introduces the working principle and system constitution of the linear Fresnel solar lithium bromide absorption refrigeration cycle, and elaborates several typical structures of absorption refrigeration cycle, including single-effect, two-stage cycle and double-effect lithium bromide absorption refrigeration cycle A 1.n effect absorption chiller system based on the best parameters was introduced and applied to a linear Fresnel solar absorption chiller system. Through the field refrigerator performance test, the results show: Based on this heat cycle design and processing 1.n lithium bromide absorption refrigeration power up to 35.2KW, It can meet the theoretical expectations and has good flexibility and reliability, provides guidance for the use of solar thermal energy.

Investigation of broadening and shift of vapour absorption lines of H{sub 2}{sup 16}O in the frequency range 7184 – 7186 cm{sup -1}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nadezhdinskii, A I; Pereslavtseva, A A; Ponurovskii, Ya Ya

2014-10-31

We present the results of investigation of water vapour absorption spectra in the 7184 – 7186 cm{sup -1} range that is of particular interest from the viewpoint of possible application of the data obtained for monitoring water vapour in the Earth's stratosphere. The doublet of H{sub 2}{sup 16}O near ν = 7185.596 cm{sup -1} is analysed. The coefficients of broadening and shift of water vapour lines are found in the selected range in mixtures with buffer gases and compared to those obtained by other authors. (laser spectroscopy)

The water vapour self-continuum absorption in the infrared atmospheric windows: new laser measurements near 3.3 and 2.0 µm

NASA Astrophysics Data System (ADS)

Lechevallier, Loic; Vasilchenko, Semen; Grilli, Roberto; Mondelain, Didier; Romanini, Daniele; Campargue, Alain

2018-04-01

The amplitude, the temperature dependence, and the physical origin of the water vapour absorption continuum are a long-standing issue in molecular spectroscopy with direct impact in atmospheric and planetary sciences. In recent years, we have determined the self-continuum absorption of water vapour at different spectral points of the atmospheric windows at 4.0, 2.1, 1.6, and 1.25 µm, by highly sensitive cavity-enhanced laser techniques. These accurate experimental constraints have been used to adjust the last version (3.2) of the semi-empirical MT_CKD model (Mlawer-Tobin_Clough-Kneizys-Davies), which is widely incorporated in atmospheric radiative-transfer codes. In the present work, the self-continuum cross-sections, CS, are newly determined at 3.3 µm (3007 cm-1) and 2.0 µm (5000 cm-1) by optical-feedback-cavity enhanced absorption spectroscopy (OFCEAS) and cavity ring-down spectroscopy (CRDS), respectively. These new data allow extending the spectral coverage of the 4.0 and 2.1 µm windows, respectively, and testing the recently released 3.2 version of the MT_CKD continuum. By considering high temperature literature data together with our data, the temperature dependence of the self-continuum is also obtained.

Status of not-in-kind refrigeration technologies for household space conditioning, water heating and food refrigeration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep; Vineyard, Edward Allan; Abdelaziz, Omar

This paper presents a review of the next generation not-in-kind technologies to replace conventional vapor compression refrigeration technology for household applications. Such technologies are sought to provide energy savings or other environmental benefits for space conditioning, water heating and refrigeration for domestic use. These alternative technologies include: thermoacoustic refrigeration, thermoelectric refrigeration, thermotunneling, magnetic refrigeration, Stirling cycle refrigeration, pulse tube refrigeration, Malone cycle refrigeration, absorption refrigeration, adsorption refrigeration, and compressor driven metal hydride heat pumps. Furthermore, heat pump water heating and integrated heat pump systems are also discussed due to their significant energy saving potential for water heating and space conditioningmore » in households. The paper provides a snapshot of the future R&D needs for each of the technologies along with the associated barriers. Both thermoelectric and magnetic technologies look relatively attractive due to recent developments in the materials and prototypes being manufactured.« less

High-quality electromagnetically-induced absorption resonances in a buffer-gas-filled vapour cell

NASA Astrophysics Data System (ADS)

Brazhnikov, D. V.; Ignatovich, S. M.; Vishnyakov, V. I.; Skvortsov, M. N.; Andreeva, Ch; Entin, V. M.; Ryabtsev, I. I.

2018-02-01

Magneto-optical subnatural-linewidth resonances of electromagnetically-induced absorption (EIA) in an alkali vapour cell have been experimentally studied. The observation configuration includes using two counter-propagating pumps and probe light waves with mutually orthogonal linear polarizations, exciting an open optical transition in the 87Rb D 1 line in the presence of argon buffer gas. The EIA signals registered in a probe-wave transmission reach an unprecedented contrast of about 135% with respect to the wide ‘Doppler’ absorption pedestal and 29% with respect to the level of background transmission signal. These contrast values correspond to a relatively small resonance full width at half maximum of about 7.2 mG (5.2 kHz). The width of the narrowest EIA resonance observed is about 2.1 mG (1.5 kHz). To our knowledge, such a large relative contrast at the kHz-width is the record result for EIA resonances. In general, the work has experimentally proved that the magneto-optical scheme used has very good prospects for various quantum technologies (quantum sensors of weak magnetic fields, optical switches and other photonic elements).

Dual-circuit, multiple-effect refrigeration system and method

DOEpatents

DeVault, Robert C.

1995-01-01

A dual circuit absorption refrigeration system comprising a high temperature single-effect refrigeration loop and a lower temperature double-effect refrigeration loop separate from one another and provided with a double-condenser coupling therebetween. The high temperature condenser of the single-effect refrigeration loop is double coupled to both of the generators in the double-effect refrigeration loop to improve internal heat recovery and a heat and mass transfer additive such as 2-ethyl-1-hexanol is used in the lower temperature double-effect refrigeration loop to improve the performance of the absorber in the double-effect refrigeration loop.

Effects of Noise-Induced Coherence on the Performance of Quantum Absorption Refrigerators

NASA Astrophysics Data System (ADS)

Holubec, Viktor; Novotný, Tomáš

2018-05-01

We study two models of quantum absorption refrigerators with the main focus on discerning the role of noise-induced coherence on their thermodynamic performance. Analogously to the previous studies on quantum heat engines, we find the increase in the cooling power due to the mechanism of noise-induced coherence. We formulate conditions imposed on the microscopic parameters of the models under which they can be equivalently described by classical stochastic processes and compare the performance of the two classes of fridges (effectively classical vs. truly quantum). We find that the enhanced performance is observed already for the effectively classical systems, with no significant qualitative change in the quantum cases, which suggests that the noise-induced-coherence-enhancement mechanism is caused by static interference phenomena.

WALES: water vapour lidar experiment in space

NASA Astrophysics Data System (ADS)

Guerin, F.; Pain, Th.; Palmade, J.-L.; Pailharey, E.; Giraud, D.; Jubineau, F.

2017-11-01

The WAter vapour Lidar Experiment in Space (WALES) mission aims at providing water vapour profiles with high accuracy and vertical resolution through the troposphere and the lower stratosphere on a global scale using an instrument based on Differential Absorption Lidar (DIAL) observation technique, and mounted on an Earth orbiting satellite. This active DIAL technique will also provide data on the cloud coverage by means of the signal reflection on the cloud layers. In DIAL operation, backscatter lidar signals at two wavelengths - at least - are detected. One wavelength (λ ON) is highly absorbed by the species of interest, while the other (λ OFF) is backscattered with minimal absorption. This difference in absorption at the two transmitted wavelengths leads to the determination of the concentration of the species of interest. The DIAL is therefore a dual-wavelength lidar in which the signals detected at the two wavelengths are processed to extract the absolute density of water vapour. The Phase A study performed by ALCATEL Space and their partners under contract of the European Space Agency has led to a credible and innovative concept of instrument, based on a mission performance modelling. The challenge is to foster the scientific return while minimising the development risks and costs of instrument development, in particular the laser transmitter. The paper describes the payload design and the implementation on a low Earth orbiting (LEO) satellite.

WALES: WAter vapour Lidar Experiment in Space

NASA Astrophysics Data System (ADS)

Guerin, F.; Pain, Th.; Palmade, J. L.; Pailharey, E.; Giraud, D.; Jubineau, F.

2004-06-01

The WAter vapour Lidar Experiment in Space (WALES) mission aims at providing water vapour profiles with high accuracy and vertical resolution through the troposphere and the lower stratosphere on a global scale using an instrument based on Differential Absorption Lidar (DIAL) observation technique, and mounted on an Earth orbiting satellite. This active DIAL technique will also provide data on the cloud coverage by means of the signal reflection on the cloud layers. In DIAL operation, backscatter lidar signals at two wavelengths - at least - are detected. One wavelength (λ ON) is highly absorbed by the species of interest, while the other (λ OFF) is backscattered with minimal absorption. This difference in absorption at the two transmitted wavelengths leads to the determination of the concentration of the species of interest. The DIAL is therefore a dual-wavelength lidar in which the signals detected at the two wavelengths are processed to extract the absolute density of water vapour. The Phase A study performed by ALCATEL Space and their partners under contract of the European Space Agency has led to a credible and innovative concept of instrument, based on a mission performance modelling. The challenge is to foster the scientific return while minimising the development risks and costs of instrument development, in particular the laser transmitter. The paper describes the payload design and the implementation on a low Earth orbiting (LEO) satellite.

A new method of search design of refrigerating systems containing a liquid and gaseous working medium based on the graph model of the physical operating principle

NASA Astrophysics Data System (ADS)

Yakovlev, A. A.; Sorokin, V. S.; Mishustina, S. N.; Proidakova, N. V.; Postupaeva, S. G.

2017-01-01

The article describes a new method of search design of refrigerating systems, the basis of which is represented by a graph model of the physical operating principle based on thermodynamical description of physical processes. The mathematical model of the physical operating principle has been substantiated, and the basic abstract theorems relatively semantic load applied to nodes and edges of the graph have been represented. The necessity and the physical operating principle, sufficient for the given model and intended for the considered device class, were demonstrated by the example of a vapour-compression refrigerating plant. The example of obtaining a multitude of engineering solutions of a vapour-compression refrigerating plant has been considered.

Predicting CO2 Solubility in Imidazole Ionic Liquids for Use in Absorption Refrigeration Systems by Using the Group Contribution Equation of State Method

NASA Astrophysics Data System (ADS)

Wu, Wei-Dong; Wu, Jun; Hou, Yong; Su, Lin; Zhang, Hua

2017-09-01

Traditional absorption refrigeration such as H2O-LiBr- and NH3-H2O-based refrigeration has limited applications because of several issues, including crystallization, corrosion, and large volume. CO2-ionic liquids (ILs) as new absorption working pairs were investigated in this study. The objective was to use the group contribution equation of state (GC-EOS) method to predict the solubilities of binary systems containing high-pressure CO2-imidazole bis(trifluoromethanesulfonimide) ILs and to investigate the applicability and accuracy of the GC-EOS model. The results showed that at pressures up to 11.0 MPa and temperatures of 273 K to 400 K, the CO2 solubility in the ILs increased with increasing system pressure but decreased with increasing temperature, and its variation rate was lower at higher pressures or temperatures. Also, CO2 solubility increased in the order of [emim][Tf2N] < [bmim][Tf2N] < [hmim][Tf2N] < [omim][Tf2N], indicating that longer alkyl chains of identical IL families resulted in higher CO_{2 } solubility. The model prediction of CO2 solubility in the four different ILs showed reasonable consistency with the corresponding experimental results from the literature; the largest deviation was 5.7 % for CO2-[emim][Tf2N]. Therefore, it can be concluded that the GC-EOS model is a promising theoretical solution that can be used to search for suitable CO2-IL working pairs for absorption refrigeration systems.

Performance modeling of optical refrigerators

NASA Astrophysics Data System (ADS)

Mills, Gary; Mord, Allan

2006-02-01

Optical refrigeration using anti-Stokes fluorescence in solids has several advantages over more conventional techniques including low mass, low volume, low cost and no vibration. It also has the potential of allowing miniature cryocoolers on the scale of a few cubic centimeters. It has been the topic of analysis and experimental work by several organizations. In 2003, we demonstrated the first optical refrigerator. We have developed a comprehensive system-level performance model of optical refrigerators. Our current version models the refrigeration cycle based on the fluorescent material emission and absorption data at ambient and reduced temperature for the Ytterbium-ZBLAN glass (Yb:ZBLAN) cooling material. It also includes the heat transfer into the refrigerator cooling assembly due to radiation and conduction. In this paper, we report on modeling results which reveal the interplay between size, power input, and cooling load. This interplay results in practical size limitations using Yb:ZBLAN.

Adsorption Refrigeration System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Kai; Vineyard, Edward Allan

Adsorption refrigeration is an environmentally friendly cooling technology which could be driven by recovered waste heat or low-grade heat such as solar energy. In comparison with absorption system, an adsorption system has no problems such as corrosion at high temperature and salt crystallization. In comparison with vapor compression refrigeration system, it has the advantages of simple control, no moving parts and less noise. This paper introduces the basic theory of adsorption cycle as well as the advanced adsorption cycles such as heat and mass recovery cycle, thermal wave cycle and convection thermal wave cycle. The types, characteristics, advantages and drawbacksmore » of different adsorbents used in adsorption refrigeration systems are also summarized. This article will increase the awareness of this emerging cooling technology among the HVAC engineers and help them select appropriate adsorption systems in energy-efficient building design.« less

In situ measurement of CO2 and water vapour isotopic compositions at a forest site using mid-infrared laser absorption spectroscopy.

PubMed

Wada, Ryuichi; Matsumi, Yutaka; Takanashi, Satoru; Nakai, Yuichiro; Nakayama, Tomoki; Ouchi, Mai; Hiyama, Tetsuya; Fujiyoshi, Yasushi; Nakano, Takashi; Kurita, Naoyuki; Muramoto, Kenichiro; Kodama, Naomi

2016-12-01

We conducted continuous, high time-resolution measurements of CO2 and water vapour isotopologues ((16)O(12)C(16)O, (16)O(13)C(16)O and (18)O(12)C(16)O for CO2, and H2(18)O for water vapour) in a red pine forest at the foot of Mt. Fuji for 9 days from the end of July 2010 using in situ absorption laser spectroscopy. The δ(18)O values in water vapour were estimated using the δ(2)H-δ(18)O relationship. At a scale of several days, the temporal variations in δ(18)O-CO2 and δ(18)O-H2O are similar. The orders of the daily Keeling plots are almost identical. A possible reason for the similar behaviour of δ(18)O-CO2 and δ(18)O-H2O is considered to be that the air masses with different water vapour isotopic ratios moved into the forest, and changed the atmosphere of the forest. A significant correlation was observed between δ(18)O-CO2 and δ(13)C-CO2 values at nighttime (r(2)≈0.9) due to mixing between soil (and/or leaf) respiration and tropospheric CO2. The ratios of the discrimination coefficients (Δa/Δ) for oxygen (Δa) and carbon (Δ) isotopes during photosynthesis were estimated in the range of 0.7-1.2 from the daytime correlations between δ(18)O-CO2 and δ(13)C-CO2 values.

A Preliminary Study on Designing and Testing of an Absorption Refrigeration Cycle Powered by Exhaust Gas of Combustion Engine

NASA Astrophysics Data System (ADS)

Napitupulu, F. H.; Daulay, F. A.; Dedy, P. M.; Denis; Jecson

2017-03-01

In order to recover the waste heat from the exhaust gas of a combustion engine, an adsorption refrigeration cycle is proposed. This is a preliminary study on design and testing of a prototype of absorption refrigeration cycle powered by an internal combustion engine. The heat source of the cycle is a compression ignition engine which generates 122.36 W of heat in generator of the cycle. The pairs of absorbent and refrigerant are water and ammonia. Here the generator is made of a shell and tube heat exchanger with number of tube and its length are 20 and 0.69 m, respectively. In the experiments the exhaust gas, with a mass flow rate of 0.00016 kg/s, enters the generator at 110°C and leaves it at 72°C. Here, the solution is heated from 30°C to 90°C. In the evaporator, the lowest temperature can be reached is 17.9°C and COP of the system is 0.45. The main conclusion can be drawn here is that the proposed system can be used to recycle the waste heat and produced cooling. However, the COP is still low.

Determination of total mercury in environmental and biological samples by flow injection cold vapour atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Murphy, James; Jones, Phil; Hill, Steve J.

1996-12-01

A simple and accurate method has been developed for the determination of total mercury in environmental and biological samples. The method utilises an off-line microwave digestion stage followed by analysis using a flow injection system with detection by cold vapour atomic absorption spectrometry. The method has been validated using two certified reference materials (DORM-1 dogfish and MESS-2 estuarine sediment) and the results agreed well with the certified values. A detection limit of 0.2 ng g -1 Hg was obtained and no significant interference was observed. The method was finally applied to the determination of mercury in river sediments and canned tuna fish, and gave results in the range 0.1-3.0 mg kg -1.

Evaluation of absorption cycle for space station environmental control system application

NASA Technical Reports Server (NTRS)

Sims, W. H.; Oneill, M. J.; Reid, H. C.; Bisenius, P. M.

1972-01-01

The study to evaluate an absorption cycle refrigeration system to provide environmental control for the space stations is reported. A zero-gravity liquid/vapor separator was designed and tested. The results were used to design a light-weight, efficient generator for the absorption refrigeration system. It is concluded that absorption cycle refrigeration is feasible for providing space station environmental control.

Absorption Heat Pump Cycles

NASA Astrophysics Data System (ADS)

Kunugi, Yoshifumi; Kashiwagi, Takao

Various advanced absorption cycles are studied, developed and invented. In this paper, their cycles are classified and arranged using the three categories: effect, stage and loop, then an outline of the cycles are explained on the Duehring diagram. Their cycles include high COP cycles for refrigerations and heat pumps, high temperature lift cycles for heat transformer, absorption-compression hybrid cycles and heat pump transformer cycle. The highest COPi is attained by the seven effect cycle. In addition, the cycles for low temperature are invented and explained. Furthermore the power generation • refrigeration cycles are illustrated.

Maximizing NGL recovery by refrigeration optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baldonedo H., A.H.

1999-07-01

PDVSA--Petroleo y Gas, S.A. has within its facilities in Lake Maracaibo two plants that extract liquids from natural gas (NGL), They use a combined mechanic refrigeration absorption with natural gasoline. Each of these plants processes 420 MMsccfd with a pressure of 535 psig and 95 F that comes from the compression plants PCTJ-2 and PCTJ-3 respectively. About 40 MMscfd of additional rich gas comes from the high pressure system. Under the present conditions these plants produce in the order of 16,800 and 23,800 b/d of NGL respectively, with a propane recovery percentage of approximately 75%, limited by the capacity ofmore » the refrigeration system. To optimize the operation and the design of the refrigeration system and to maximize the NGL recovery, a conceptual study was developed in which the following aspects about the process were evaluated: capacity of the refrigeration system, refrigeration requirements, identification of limitations and evaluation of the system improvements. Based on the results obtained it was concluded that by relocating some condensers, refurbishing the main refrigeration system turbines and using HIGH FLUX piping in the auxiliary refrigeration system of the evaporators, there will be an increase of 85% on the propane recovery, with an additional production of 25,000 b/d of NGL and 15 MMscfd of ethane rich gas.« less

Refrigeration generation using expander-generator units

NASA Astrophysics Data System (ADS)

Klimenko, A. V.; Agababov, V. S.; Koryagin, A. V.; Baidakova, Yu. O.

2016-05-01

The problems of using the expander-generator unit (EGU) to generate refrigeration, along with electricity were considered. It is shown that, on the level of the temperatures of refrigeration flows using the EGU, one can provide the refrigeration supply of the different consumers: ventilation and air conditioning plants and industrial refrigerators and freezers. The analysis of influence of process parameters on the cooling power of the EGU, which depends on the parameters of the gas expansion process in the expander and temperatures of cooled environment, was carried out. The schematic diagram of refrigeration generation plant based on EGU is presented. The features and advantages of EGU to generate refrigeration compared with thermotransformer of steam compressive and absorption types were shown, namely: there is no need to use the energy generated by burning fuel to operate the EGU; beneficial use of the heat delivered to gas from the flow being cooled in equipment operating on gas; energy production along with refrigeration generation, which makes it possible to create, using EGU, the trigeneration plants without using the energy power equipment. It is shown that the level of the temperatures of refrigeration flows, which can be obtained by using the EGU on existing technological decompression stations of the transported gas, allows providing the refrigeration supply of various consumers. The information that the refrigeration capacity of an expander-generator unit not only depends on the parameters of the process of expansion of gas flowing in the expander (flow rate, temperatures and pressures at the inlet and outlet) but it is also determined by the temperature needed for a consumer and the initial temperature of the flow of the refrigeration-carrier being cooled. The conclusion was made that the expander-generator units can be used to create trigeneration plants both at major power plants and at small energy.

Corrosion Problems in Absorption Chillers

ERIC Educational Resources Information Center

Stetson, Bruce

1978-01-01

Absorption chillers use a lithium bromide solution as the medium of absorption and water as the refrigerant. Discussed are corrosion and related problems, tests and remedies, and cleaning procedures. (Author/MLF)

Evaluation and selection of refrigeration systems for lunar surface and space applications

NASA Technical Reports Server (NTRS)

Copeland, R. J.; Blount, T. D.; Williams, J. L.

1971-01-01

Evaluated are the various refrigeration machines which could be used to provide heat rejection in environmental control systems for lunar surface and spacecraft applications, in order to select the best refrigeration machine for satisfying each individual application and the best refrigeration machine for satisfying all of the applications. The refrigeration machine considered include: (1) vapor comparison cycle (work-driven); (2) vapor adsorption cycle (heat-driven); (3) vapor absorption cycle (heat-driven); (4) thermoelectric (electrically-driven); (5) gas cycle (work driven); (6) steam-jet (heat-driven).

Intercomparison of atmospheric water vapour measurements at a Canadian High Arctic site

NASA Astrophysics Data System (ADS)

Weaver, Dan; Strong, Kimberly; Schneider, Matthias; Rowe, Penny M.; Sioris, Chris; Walker, Kaley A.; Mariani, Zen; Uttal, Taneil; McElroy, C. Thomas; Vömel, Holger; Spassiani, Alessio; Drummond, James R.

2017-08-01

Water vapour is a critical component of the Earth system. Techniques to acquire and improve measurements of atmospheric water vapour and its isotopes are under active development. This work presents a detailed intercomparison of water vapour total column measurements taken between 2006 and 2014 at a Canadian High Arctic research site (Eureka, Nunavut). Instruments include radiosondes, sun photometers, a microwave radiometer, and emission and solar absorption Fourier transform infrared (FTIR) spectrometers. Close agreement is observed between all combination of datasets, with mean differences ≤ 1.0 kg m-2 and correlation coefficients ≥ 0.98. The one exception in the observed high correlation is the comparison between the microwave radiometer and a radiosonde product, which had a correlation coefficient of 0.92.A variety of biases affecting Eureka instruments are revealed and discussed. A subset of Eureka radiosonde measurements was processed by the Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) for this study. Comparisons reveal a small dry bias in the standard radiosonde measurement water vapour total columns of approximately 4 %. A recently produced solar absorption FTIR spectrometer dataset resulting from the MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) retrieval technique is shown to offer accurate measurements of water vapour total columns (e.g. average agreement within -5.2 % of GRUAN and -6.5 % of a co-located emission FTIR spectrometer). However, comparisons show a small wet bias of approximately 6 % at the high-latitude Eureka site. In addition, a new dataset derived from Atmospheric Emitted Radiance Interferometer (AERI) measurements is shown to provide accurate water vapour measurements (e.g. average agreement was within 4 % of GRUAN), which usefully enables measurements to be taken during day and night (especially valuable during polar night).

A general computer model for predicting the performance of gas sorption refrigerators

NASA Technical Reports Server (NTRS)

Sigurdson, K. B.

1983-01-01

Projected performance requirements for cryogenic spacecraft sensor cooling systems which demand higher reliability and longer lifetimes are outlined. The gas/solid sorption refrigerator is viewed as a potential solution to cryogenic cooling needs. A software model of an entire gas sorption refrigerator system was developed. The numerical model, evaluates almost any combination and order of refrigerator components and any sorbent-sorbate pair or which the sorption isotherm data are available. Parametric curves for predicting system performance were generated for two types of refrigerators, a LaNi5-H2 absorption cooler and a Charcoal-N2 adsorption cooler. It is found that precooling temperature and heat exchanger effectiveness affect the refrigerator performance. It is indicated that gas sorption refrigerators are feasible for a number of space applications.

Quantum speed limit constraints on a nanoscale autonomous refrigerator

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Chiranjib; Misra, Avijit; Bhattacharya, Samyadeb; Pati, Arun Kumar

2018-06-01

Quantum speed limit, furnishing a lower bound on the required time for the evolution of a quantum system through the state space, imposes an ultimate natural limitation to the dynamics of physical devices. Quantum absorption refrigerators, however, have attracted a great deal of attention in the past few years. In this paper, we discuss the effects of quantum speed limit on the performance of a quantum absorption refrigerator. In particular, we show that there exists a tradeoff relation between the steady cooling rate of the refrigerator and the minimum time taken to reach the steady state. Based on this, we define a figure of merit called "bounding second order cooling rate" and show that this scales linearly with the unitary interaction strength among the constituent qubits. We also study the increase of bounding second-order cooling rate with the thermalization strength. We subsequently demonstrate that coherence in the initial three qubit system can significantly increase the bounding second-order cooling rate. We study the efficiency of the refrigerator at maximum bounding second-order cooling rate and, in a limiting case, we show that the efficiency at maximum bounding second-order cooling rate is given by a simple formula resembling the Curzon-Ahlborn relation.

Diode laser-induced infrared fluorescence of water vapour

NASA Astrophysics Data System (ADS)

Li, Hejie; Hanson, Ronald K.; Jeffries, Jay B.

2004-07-01

Infrared laser-induced fluorescence (LIF) of water vapour was investigated for its potential as a spatially resolved gasdynamic diagnostic. A cw diode laser operating near 1392 nm was scanned across a single absorption transition in the ngr1 + ngr3 band of H2O in a static cell, and the resulting fluorescence signal was collected near 2.7 µm (both ngr1 and ngr3 bands). Experiments were conducted at low pressure in pure water vapour and mixtures of water vapour and N2 using a 20 mW laser in a double-pass arrangement. A simple analytical model was developed to relate LIF intensity to gas properties as a function of laser power. The spectrally resolved, single-line excitation spectrum was fitted with a Voigt profile, allowing inference of the water vapour temperature from the Doppler-broadened component of the measured fluorescence lineshape. A two-line excitation scheme was also investigated as a means of measuring temperature with reduced measurement time. From these initial measurements, we estimate that a practical sensor for atmospheric pressure applications would require a minimum of 1-2 W of laser power for two-line, fixed-wavelength temperature measurements and a minimum of about 70 W of power for scanned-wavelength measurements.

Performance of solar refrigerant ejector refrigerating machine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Khalidy, N.A.H.

1997-12-31

In this work a detailed analysis for the ideal, theoretical, and experimental performance of a solar refrigerant ejector refrigerating machine is presented. A comparison of five refrigerants to select a desirable one for the system is made. The theoretical analysis showed that refrigerant R-113 is more suitable for use in the system. The influence of the boiler, condenser, and evaporator temperatures on system performance is investigated experimentally in a refrigerant ejector refrigerating machine using R-113 as a working refrigerant.

Nanofibrous membrane-based absorption refrigeration system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isfahani, RN; Sampath, K; Moghaddam, S

2013-12-01

This paper presents a study on the efficacy of highly porous nanofibrous membranes for application in membrane-based absorbers and desorbers. Permeability studies showed that membranes with a pore size greater than about one micron have a sufficient permeability for application in the absorber heat exchanger. Membranes with smaller pores were found to be adequate for the desorber heat exchanger. The membranes were implemented in experimental membrane-based absorber and desorber modules and successfully tested. Parametric studies were conducted on both absorber and desorber processes. Studies on the absorption process were focused on the effects of water vapor pressure, cooling water temperature,more » and the solution velocity on the absorption rate. Desorption studies were conducted on the effects of wall temperature, vapor and solution pressures, and the solution velocity on the desorption rate. Significantly higher absorption and desorption rates than in the falling film absorbers and desorbers were achieved. Published by Elsevier Ltd.« less

Infrared Laser Optoacoustic Detection Of Gases And Vapours

NASA Astrophysics Data System (ADS)

Johnson, S. A.; Cummins, P. G.; Bone, S. A.; Davies, P. B.

1988-10-01

Mid-infrared laser optoacoustic spectroscopy has been used to detect a variety of gases and vapours. Performance was calibrated using the signal from a known concentration of ethene, and then the method applied to the perfume alcohol geraniol. Detection limits were found to be 1 ppb for ethene and 70 ppb for geraniol on their strongest absorption lines for a few seconds measurement time.

Alcohol vapours sensor based on thin polyaniline salt film and quartz crystal microbalance.

PubMed

Ayad, Mohamad M; Torad, Nagy L

2009-06-15

A sensor based on the quartz crystal microbalance (QCM) technique was developed for detection of a number of primary aliphatic alcohols such as ethanol, methanol, 1-propanol, and 2-propanol vapours. Detection was based on a sensitive and a thin film of polyaniline, emeraldine salt (ES), coated the QCM electrode. The frequency shifts (Delta f) of the QCM were increased due to the vapour absorption into the ES film. The values of Delta f were found to be linearly correlated with the concentrations of alcohols vapour in mg L(-1). The changes in frequency are due to the hydrophilic character of the ES and the electrostatic interaction as well as the type of the alcohol. The sensor shows a good reproducibility and reversibility. The diffusion and diffusion coefficient (D) of different alcohols vapour were determined. It was found that the sensor follows Fickian kinetics.

Development of a wavelength stabilized seed laser system for an airborne water vapour lidar experiment

NASA Astrophysics Data System (ADS)

Schwarzer, H.; Börner, A.; Fix, A.; Günther, B.; Hübers, H.-W.; Raugust, M.; Schrandt, F.; Wirth, M.

2007-09-01

At the German Aerospace Center an airborne multi-wavelength differential absorption LIDAR for the measurement of atmospheric water vapour is currently under development. This instrument will enable the retrieval of the complete humidity profile from the surface up to the lowermost stratosphere with high vertical and horizontal resolution at a systematic error below 5%. The LIDAR will work in the wavelength region around 935 nm at three different water vapour absorption lines and one reference wavelength. A major sub-system of this instrument is a highly frequency stabilized seed laser system for the optical parametrical oscillators which generate the narrowband high energy light pulses. The development of the seed laser system includes the control software, the electronic control unit and the opto-mechanical layout. The seed lasers are Peltier-cooled distributed feedback laser diodes with bandwidths of about 30 MHz, each one operating for 200 μs before switching to the next one. The required frequency stability is +/- 30 MHz ≅ +/- 10 -4 nm under the rough environmental conditions aboard an aircraft. It is achieved by locking the laser wavelength to a water vapour absorption line. The paper describes the opto-mechanical layout of the seed laser system, the stabilization procedure and the results obtained with this equipment.

Advancement of Double Effect Absorption Cycle by Input of Low Temperature Waste Heat

NASA Astrophysics Data System (ADS)

Kojima, Hiroshi; Edera, Masaru; Nakamura, Makoto; Oka, Masahiro; Akisawa, Atsushi; Kashiwagi, Takao

Energy conservation is becoming important for global environmental protection. New simple techniques of more efficient1y using the waste heat of gas co-generation systems for refrigerationare required. In first report, a new method of using the low temperature waste heat for refrigeration was proposed, and the basic characteristics of the promising methods of recovering waste heat were c1arified. In this report, the more detailed simulation model of the series flow type double effect absorption refrigerator with auxiliary heat exchanger was constructed and the static characteristics were investigated. Then experiments on this advanced absorption refrigerator were carried out, and the results of the calculation and experiments were compared and discussed. Moreover, the betterment of the simulation model of this advanced absorption refrigerator was carried out.

Advanced regenerative absorption refrigeration cycles

DOEpatents

Dao, Kim

1990-01-01

Multi-effect regenerative absorption cycles which provide a high coefficient of performance (COP) at relatively high input temperatures. An absorber-coupled double-effect regenerative cycle (ADR cycle) (10) is provided having a single-effect absorption cycle (SEA cycle) (11) as a topping subcycle and a single-effect regenerative absorption cycle (1R cycle) (12) as a bottoming subcycle. The SEA cycle (11) includes a boiler (13), a condenser (21), an expansion device (28), an evaporator (31), and an absorber (40), all operatively connected together. The 1R cycle (12) includes a multistage boiler (48), a multi-stage resorber (51), a multisection regenerator (49) and also uses the condenser (21), expansion device (28) and evaporator (31) of the SEA topping subcycle (11), all operatively connected together. External heat is applied to the SEA boiler (13) for operation up to about 500 degrees F., with most of the high pressure vapor going to the condenser (21) and evaporator (31) being generated by the regenerator (49). The substantially adiabatic and isothermal functioning of the SER subcycle (12) provides a high COP. For higher input temperatures of up to 700 degrees F., another SEA cycle (111) is used as a topping subcycle, with the absorber (140) of the topping subcycle being heat coupled to the boiler (13) of an ADR cycle (10). The 1R cycle (12) itself is an improvement in that all resorber stages (50b-f) have a portion of their output pumped to boiling conduits (71a-f) through the regenerator (49), which conduits are connected to and at the same pressure as the highest pressure stage (48a) of the 1R multistage boiler (48).

Architecture for Absorption Based Heaters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moghaddam, Saeed; Chugh, Devesh

An absorption based heater is constructed on a fluid barrier heat exchanging plate such that it requires little space in a structure. The absorption based heater has a desorber, heat exchanger, and absorber sequentially placed on the fluid barrier heat exchanging plate. The vapor exchange faces of the desorber and the absorber are covered by a vapor permeable membrane that is permeable to a refrigerant vapor but impermeable to an absorbent. A process fluid flows on the side of the fluid barrier heat exchanging plate opposite the vapor exchange face through the absorber and subsequently through the heat exchanger. Themore » absorption based heater can include a second plate with a condenser situated parallel to the fluid barrier heat exchanging plate and opposing the desorber for condensation of the refrigerant for additional heating of the process fluid.« less

Cryogenic Optical Refrigeration

DTIC Science & Technology

2012-03-22

Applications of Laser Cooling of Solids, 1st ed. (Wiley-VCH, 2009). 12. M. Sheik- Bahae and R. I . Epstein, “Optical refrigeration,” Nat. Photonics 1(12), 693–699...2007). Advances in Optics and Photonics 4, 78–107 (2012) doi:10.1364/AOP.4.000078 99 13. M. Sheik- Bahae and R. I . Epstein, “Laser cooling of solids...Sheik- Bahae and R. I . Epstein, “Can laser light cool semiconductors,” Phys. Rev. Lett. 92(24), 247403 (2004). 18. P. Asbeck, “Self-absorption effects

Solid-state optical refrigeration to sub-100 Kelvin regime

PubMed Central

Melgaard, Seth D.; Albrecht, Alexander R.; Hehlen, Markus P.; Sheik-Bahae, Mansoor

2016-01-01

Since the first demonstration of net cooling twenty years ago, optical refrigeration of solids has progressed to outperform all other solid-state cooling processes. It has become the first and only solid-state refrigerator capable of reaching cryogenic temperatures, and now the first solid-state cooling below 100 K. Such substantial progress required a multi-disciplinary approach of pump laser absorption enhancement, material characterization and purification, and thermal management. Here we present the culmination of two decades of progress, the record cooling to ≈ 91 K from room temperature. PMID:26847703

Solid-state optical refrigeration to sub-100 Kelvin regime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melgaard, Seth D.; Albrecht, Alexander R.; Hehlen, Markus P.

We report that since the first demonstration of net cooling twenty years ago, optical refrigeration of solids has progressed to outperform all other solid-state cooling processes. It has become the first and only solid-state refrigerator capable of reaching cryogenic temperatures, and now the first solid-state cooling below 100 K. Such substantial progress required a multi-disciplinary approach of pump laser absorption enhancement, material characterization and purification, and thermal management. Here we present the culmination of two decades of progress, the record cooling to ≈91K from room temperature.

Solid-state optical refrigeration to sub-100 Kelvin regime

DOE PAGES

Melgaard, Seth D.; Albrecht, Alexander R.; Hehlen, Markus P.; ...

2016-02-05

We report that since the first demonstration of net cooling twenty years ago, optical refrigeration of solids has progressed to outperform all other solid-state cooling processes. It has become the first and only solid-state refrigerator capable of reaching cryogenic temperatures, and now the first solid-state cooling below 100 K. Such substantial progress required a multi-disciplinary approach of pump laser absorption enhancement, material characterization and purification, and thermal management. Here we present the culmination of two decades of progress, the record cooling to ≈91K from room temperature.

Alternative refrigerants and refrigeration cycles for domestic refrigerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sand, J.R.; Rice, C.L.; Vineyard, E.A.

1992-12-01

This project initially focused on using nonazeotropic refrigerant mixtures (NARMs) in a two-evaporator refrigerator-freezer design using two stages of liquid refrigerant subcooling. This concept was proposed and tested in 1975. The work suggested that the concept was 20% more efficient than the conventional one-evaporator refrigerator-freezer (RF) design. After considerable planning and system modeling based on using a NARM in a Lorenz-Meutzner (L-M) RF, the program scope was broadened to include investigation of a ``dual-loop`` concept where energy savings result from exploiting the less stringent operating conditions needed to satisfy cooling, of the fresh food section. A steady-state computer model (CYCLE-Z)more » capable of simulating conventional, dual loop, and L-M refrigeration cycles was developed. This model was used to rank the performance of 20 ozone-safe NARMs in the L-M refrigeration cycle while key system parameters were systematically varied. The results indicated that the steady-state efficiency of the L-M design was up to 25% greater than that of a conventional cycle. This model was also used to calculate the performance of other pure refrigerants relative to that of dichlorodifluoromethane, R-12, in conventional and dual-loop RF designs. Projected efficiency gains for these cycles were more modest, ranging from 0 to 10%. Individual compressor calorimeter tests of nine combinations of evaporator and condenser temperatures usually used to map RF compressor performance were carried out with R-12 and two candidate L-M NARMs in several compressors. Several models of a commercially produced two-evaporator RF were obtained as test units. Two dual-loop RF designs were built and tested as part of this project.« less

A thermodynamic analysis of a solar-powered jet refrigeration system

NASA Technical Reports Server (NTRS)

Lansing, F. L.; Chai, V. W.

1980-01-01

The article describes and analyzes a method of using solar energy to drive a jet refrigeration system. A new technique is presented in the form of a performance nomogram combining the energy and momentum equations to determine the performance characteristics. A numerical example, using water as the working fluid, is given to illustrate the nomogram procedure. The resulting coefficient of performance was found comparable with other refrigeration systems such as the solar-absorption system or the solar-Rankine turbocompressor system.

Alcohol vapour detection at the three phase interface using enzyme-conducting polymer composites.

PubMed

Winther-Jensen, Orawan; Kerr, Robert; Winther-Jensen, Bjorn

2014-02-15

Immobilisation of enzymes on a breathable electrode can be useful for various applications where the three-phase interface between gas or chemical vapour, electrolyte and electrode is crucial for the reaction. In this paper, we report the further development of the breathable electrode concept by immobilisation of alcohol dehydrogenase into vapour-phase polymerised poly(3,4-ethylene dioxythiophene) that has been coated onto a breathable membrane. Typical alcohol sensing, whereby the coenzyme β-Nicotinamide adenine dinucleotide (NADH) is employed as a redox-mediator, was successfully used as a model reaction for the oxidation of ethanol. This indicates that the ethanol vapour from the backside of the membrane has access to the active enzyme embedded in the electrode. The detecting range of the sensor is suitable for the detection of ethanol in fruit juices and for the baseline breath ethanol concentration of drunken driving. After continuous operation for 4.5h the system only showed a 20% decrease in the current output. The electrodes maintained 62% in current output after being refrigerated for 76 days. This work is continuing the progress of the immobilisation of specific enzymes for certain electrochemical reactions whereby the three-phase interface has to be maintained and/or the simultaneous separation of gas from liquid is required. © 2013 Elsevier B.V. All rights reserved.

Low Global Warming Potential Refrigerants for Commercial Refrigeration Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, Brian A.; Sharma, Vishaldeep; Abdelaziz, Omar

Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the highmore » refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Environmental concerns are driving regulations for the heating, ventilating, air-conditioning and refrigeration (HVAC&R) industry towards lower GWP alternatives to HFC refrigerants. Existing lower GWP refrigerant alternatives include hydrocarbons, such as propane (R-290) and isobutane (R-600a), as well as carbon dioxide (R-744), ammonia (R-717), and R-32. In addition, new lower GWP refrigerant alternatives are currently being developed by refrigerant manufacturers, including hydrofluoro-olefin (HFO) and unsaturated hydrochlorofluorocarbon (HCFO) refrigerants. The selection of an appropriate refrigerant for a given refrigeration application should be based on several factors, including the GWP of the refrigerant, the energy consumption of the refrigeration system over its operating lifetime, and leakage of refrigerant over the system lifetime. For example, focusing on energy efficiency alone may overlook the significant environmental impact of refrigerant leakage; while focusing on GWP alone might result in lower efficiency systems that result in higher indirect impact over the equipment lifetime. Thus, the objective of this Collaborative Research and Development Agreement (CRADA

Refrigeration oils for low GWP refrigerants in various applications

NASA Astrophysics Data System (ADS)

Saito, R.; Sundaresan, S. G.

2017-08-01

The practical use of the refrigeration systems is considered as a methods to suppress global warming. The replacement of a refrigerant with a new one that has lower global warming potential (GWP) has been underway for several years. For the application fields of refrigerators, domestic air conditioners, automotive air conditioners and hot water dispensers, the investigation has almost finished. It is still underway for the application fields of commercial air conditioners and chillers, refrigeration facilities for cold storage, etc. And now, the refrigeration system is being applied in various ways to decrease global warming above the generation of electric power with organic Rankine cycle, the binary electric generation with ground source heat pump, and so on. In these situations, various refrigerants are developed and several kinds of suitable refrigeration oils are selected. This paper presents the consideration of suitable refrigeration oil for the various low GWP refrigerants.

Miscibility comparison for three refrigerant mixtures and four component refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, H.M.; Pate, M.B.

1999-07-01

Miscibility data were taken and compared for seven different refrigerants when mixed with the same polyol ester (POE) lubricant. Four of the seven refrigerants were single-component refrigerants while three of the refrigerants were mixtures composed of various combinations of the pure refrigerants. The purpose of this research was to investigate the difference in miscibility characteristics between refrigerant mixtures and their respective component refrigerants. The POE lubricant was a penta erythritol mixed-acid type POE which has a viscosity ISO32. The four pure refrigerants were R-32, R-125, R-134a, and R-143a and the three refrigerant mixtures were R-404A, R407C, and R-410A. The miscibilitymore » tests were performed in a test facility consisting of a series of miniature test cells submerged in a constant temperature bath. The test cells were constructed to allow for complete visibility of the refrigerant/lubricant mixtures under all test conditions. The tests were performed over a concentration range of 0 to 100% and a temperature range of {minus}40 to 194 F. The miscibility test results for refrigerant mixtures are compared to component refrigerants. In all cases, the refrigerant mixtures appear to have better miscibility than their most immiscible pure component.« less

Refrigeration Playbook: Natural Refrigerants; Selecting and Designing Energy-Efficient Commercial Refrigeration Systems That Use Low Global Warming Potential Refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, Caleb; Reis, Chuck; Nelson, Eric

This report provides guidance for selecting and designing energy efficient commercial refrigeration systems using low global warming potential refrigerants. Refrigeration systems are generally the largest energy end use in a supermarket type building, often accounting for more than half of a building's energy consumption.

Quantum refrigerators and the third law of thermodynamics.

PubMed

Levy, Amikam; Alicki, Robert; Kosloff, Ronnie

2012-06-01

The rate of temperature decrease of a cooled quantum bath is studied as its temperature is reduced to absolute zero. The third law of thermodynamics is then quantified dynamically by evaluating the characteristic exponent ζ of the cooling process dT(t)/dt∼-T^{ζ} when approaching absolute zero, T→0. A continuous model of a quantum refrigerator is employed consisting of a working medium composed either by two coupled harmonic oscillators or two coupled two-level systems. The refrigerator is a nonlinear device merging three currents from three heat baths: a cold bath to be cooled, a hot bath as an entropy sink, and a driving bath which is the source of cooling power. A heat-driven refrigerator (absorption refrigerator) is compared to a power-driven refrigerator. When optimized, both cases lead to the same exponent ζ, showing a lack of dependence on the form of the working medium and the characteristics of the drivers. The characteristic exponent is therefore determined by the properties of the cold reservoir and its interaction with the system. Two generic heat bath models are considered: a bath composed of harmonic oscillators and a bath composed of ideal Bose/Fermi gas. The restrictions on the interaction Hamiltonian imposed by the third law are discussed. In the Appendices, the theory of periodically driven open systems and its implication for thermodynamics are outlined.

A simulation study on the abatement of CO2 emissions by de-absorption with monoethanolamine.

PubMed

Greer, T; Bedelbayev, A; Igreja, J M; Gomes, J F; Lie, B

2010-01-01

Because of the adverse effect of CO2 from fossil fuel combustion on the earth's ecosystems, the most cost-effective method for CO2 capture is an important area of research. The predominant process for CO2 capture currently employed by industry is chemical absorption in amine solutions. A dynamic model for the de-absorption process was developed with monoethanolamine (MEA) solution. Henry's law was used for modelling the vapour phase equilibrium of the CO2, and fugacity ratios calculated by the Peng-Robinson equation of state (EOS) were used for H2O, MEA, N2 and O2. Chemical reactions between CO2 and MEA were included in the model along with the enhancement factor for chemical absorption. Liquid and vapour energy balances were developed to calculate the liquid and vapour temperature, respectively.

Measurement of transient gas flow parameters by diode laser absorption spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolshov, M A; Kuritsyn, Yu A; Liger, V V

2015-04-30

An absorption spectrometer based on diode lasers is developed for measuring two-dimension maps of temperature and water vapour concentration distributions in the combustion zones of two mixing supersonic flows of fuel and oxidiser in the single run regime. The method of measuring parameters of hot combustion zones is based on detection of transient spectra of water vapour absorption. The design of the spectrometer considerably reduces the influence of water vapour absorption along the path of a sensing laser beam outside the burning chamber. The optical scheme is developed, capable of matching measurement results in different runs of mixture burning. Amore » new algorithm is suggested for obtaining information about the mixture temperature by constructing the correlation functions of the experimental spectrum with those simulated from databases. A two-dimensional map of temperature distribution in a test chamber is obtained for the first time under the conditions of plasma-induced combusion of the ethylene – air mixture. (laser applications and other topics in quantum electronics)« less

Triple effect absorption chiller utilizing two refrigeration circuits

DOEpatents

DeVault, Robert C.

1988-01-01

A triple effect absorption method and apparatus having a high coefficient of performance. Two single effect absorption circuits are combined with heat exchange occurring between a condenser and absorber of a high temperature circuit, and a generator of a low temperature circuit. The evaporators of both the high and low temperature circuits provide cooling to an external heat load.

Magnetic Refrigeration Development

NASA Technical Reports Server (NTRS)

Deardoff, D. D.; Johnson, D. L.

1984-01-01

Magnetic refrigeration is being developed to determine whether it may be used as an alternative to the Joule-Thomson circuit of a closed cycle refrigerator for providing 4 K refrigeration. An engineering model 4-15 K magnetic refrigerator has been designed and is being fabricated. This article describes the overall design of the magnetic refrigerator.

Absorption machine with desorber-resorber

DOEpatents

Biermann, Wendell J.

1985-01-01

An absorption refrigeration system utilizing a low temperature desorber and intermediate temperature resorber. The system operates at three temperatures and three pressures to increase the efficiency of the system and is capable of utilizing a lower generator temperature than previously used.

ARTI refrigerant database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

1998-03-15

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to thermophysical properties, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air conditioning and refrigeration equipment. It also references documents addressing compatibility ofmore » refrigerants and lubricants with other materials.« less

Energy Efficient Commercial Refrigeration with Carbon Dioxide Refrigerant and Scroll Expanders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dieckmann, John

Current supermarket refrigeration systems are built around conventional fluorocarbon refrigerants – HFC-134a and the HFC blends R-507 and R404A, which replaced the CFC refrigerants, R-12 and R-502, respectively, used prior to the Montreal Protocol phase out of ozone depleting substances. While the HFC refrigerants are non-ozone depleting, they are strong greenhouse gases, so there has been continued interest in replacing them, particularly in applications with above average refrigerant leakage. Large supermarket refrigeration systems have proven to be particularly difficult to maintain in a leak-tight condition. Refrigerant charge losses of 15% of total charge per year are the norm, making themore » global warming impact of refrigerant emissions comparable to that associated with the energy consumption of these systems.« less

Thermoacoustic refrigeration

NASA Technical Reports Server (NTRS)

Garrett, Steven L.; Hofler, Thomas J.

1991-01-01

A new refrigerator which uses resonant high amplitude sound in inert gases to pump heat is described and demonstrated. The phasing of the thermoacoustic cycle is provided by thermal conduction. This 'natural' phasing allows the entire refrigerator to operate with only one moving part (the loudspeaker diaphragm). The thermoacoustic refrigerator has no sliding seals, requires no lubrication, uses only low-tolerance machine parts, and contains no expensive components. Because the compressor moving mass is typically small and the oscillation frequency is high, the small amount of vibration is very easily isolated. This low vibration and lack of sliding seals makes thermoacoustic refrigeration an excellent candidate for food refrigeration and commercial/residential air conditioning applications. The design, fabrication, and performance of the first practical, autonomous thermoacoustic refrigerator, which will be flown on the Space Shuttle (STS-42), are described, and designs for terrestrial applications are presented.

REACH. Refrigeration Units.

ERIC Educational Resources Information Center

Snow, Rufus; And Others

As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of refrigeration. The instructional units focus on refrigeration fundamentals, tubing and pipe, refrigerants, troubleshooting, window air conditioning, and…

ARTI refrigerant database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

1996-07-01

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

ARTI refrigerant database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

1996-11-15

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

Malone refrigeration

NASA Astrophysics Data System (ADS)

Swift, G. W.

Malone refrigeration is the use of a liquid near its critical points without evaporations as working fluid in a regenerative or recuperative refrigeration cycle such as the Stirling and Brayton cycles. It's potential advantages include compactness, efficiency, an environmentally benign working fluid, and reasonable cost. One Malone refrigerator has been built and studied; two more are under construction. Malone refrigeration is such a new, relatively unexplored technology that the potential for inventions leading to improvements in efficiency and simplicity is very high.

ARTI refrigerant database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

1997-02-01

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alterative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some maymore » be added at a later date. The database identifies sources of specific information on various refrigerants. It addresses lubricants including alkylbenzene, polyalkylene glycol, polyolester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents. They are included to accelerate availability of the information and will be completed or replaced in future updates.« less

The ESA DUE GlobVapour Project

NASA Astrophysics Data System (ADS)

Schröder, M.; ESA Due Globvapour Project Team

2010-12-01

The European Space Agency (ESA) Data User Element (DUE) project series aims at bridging the gap between research projects and the sustainable provision of Earth Observation (EO) climate data products at an information level that fully responds to the operational needs of user communities. The ultimate objective of GlobVapour is to provide long-term coherent water vapour data sets exploiting the synergistic capabilities of different EO missions aiming at improved accuracies and enhanced temporal and spatial sampling better than those provided by the single sources. The project seeks to utilize the increasing potential of the synergistic capabilities of past, existing and upcoming satellite missions (ERS-1 and -2, ENVISAT, METOP, MSG as well as relevant non-European missions and in-situ data) in order to meet the increasing needs for coherent long-term water vapour datasets required by the scientific community. GlobVapour develops, validates and applies novel water vapour climate data sets derived from various sensors. More specifically, the primary objectives of the GlobVapour project are: 1)The development of multi-annual global water vapour data sets inclusive of error estimates based on carefully calibrated and inter-calibrated radiances. 2)The validation of the water vapour products against ground based, airborne and other satellite based measurements. 3) The provision of an assessment of the quality of different IASI water vapour profile algorithms developed by the project partners and other groups. 4) The provision of a complete processing system that can further strengthen operational production of the developed products. 5) A demonstration of the use of the products in the field of climate modelling, including applying alternative ways of climate model validation using forward radiation operators. 6) The promotion of the strategy of data set construction and the data sets themselves to the global research and operational community. The ultimate goal of the

Refrigerant directly cooled capacitors

DOEpatents

Hsu, John S [Oak Ridge, TN; Seiber, Larry E [Oak Ridge, TN; Marlino, Laura D [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN

2007-09-11

The invention is a direct contact refrigerant cooling system using a refrigerant floating loop having a refrigerant and refrigeration devices. The cooling system has at least one hermetic container disposed in the refrigerant floating loop. The hermetic container has at least one electronic component selected from the group consisting of capacitors, power electronic switches and gating signal module. The refrigerant is in direct contact with the electronic component.

When are solar refrigerators less costly than on-grid refrigerators: A simulation modeling study.

PubMed

Haidari, Leila A; Brown, Shawn T; Wedlock, Patrick; Connor, Diana L; Spiker, Marie; Lee, Bruce Y

2017-04-19

Gavi recommends solar refrigerators for vaccine storage in areas with less than eight hours of electricity per day, and WHO guidelines are more conservative. The question remains: Can solar refrigerators provide value where electrical outages are less frequent? Using a HERMES-generated computational model of the Mozambique routine immunization supply chain, we simulated the use of solar versus electric mains-powered refrigerators (hereafter referred to as "electric refrigerators") at different locations in the supply chain under various circumstances. At their current price premium, the annual cost of each solar refrigerator is 132% more than each electric refrigerator at the district level and 241% more at health facilities. Solar refrigerators provided savings over electric refrigerators when one-day electrical outages occurred more than five times per year at either the district level or the health facilities, even when the electric refrigerator holdover time exceeded the duration of the outage. Two-day outages occurring more than three times per year at the district level or more than twice per year at the health facilities also caused solar refrigerators to be cost saving. Lowering the annual cost of a solar refrigerator to 75% more than an electric refrigerator allowed solar refrigerators to be cost saving at either level when one-day outages occurred more than once per year, or when two-day outages occurred more than once per year at the district level or even once per year at the health facilities. Our study supports WHO and Gavi guidelines. In fact, solar refrigerators may provide savings in total cost per dose administered over electrical refrigerators when electrical outages are less frequent. Our study identified the frequency and duration at which electrical outages need to occur for solar refrigerators to provide savings in total cost per dose administered over electric refrigerators at different solar refrigerator prices. Copyright © 2017. Published

Portable refrigerant charge meter and method for determining the actual refrigerant charge in HVAC systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Zhiming; Abdelaziz, Omar; LaClair, Tim L.

A refrigerant charge meter and a method for determining the actual refrigerant charge in HVAC systems are described. The meter includes means for determining an optimum refrigerant charge from system subcooling and system component parameters. The meter also includes means for determining the ratio of the actual refrigerant charge to the optimum refrigerant charge. Finally, the meter includes means for determining the actual refrigerant charge from the optimum refrigerant charge and the ratio of the actual refrigerant charge to the optimum refrigerant charge.

Study on the Materials for Compressor and Reliability of Refrigeration Circuit in Refrigerator with R134a Refrigerant

NASA Astrophysics Data System (ADS)

Komatsubara, Takeo; Sunaga, Takasi; Takahasi, Yasuki

R134a was selected as the alternative refrigerant for R12 because of the similar thermodynamic properties with R12. But refrigeration oil for R12 couldn't be used for R134a because of the immiscibility with R134a. To solve this problem we researched miscible oil with R134a and selected polyol ester oil (POE) as refrigeration oil. But we found sludge deposition into capillary tube after life test of refrigerator with POE and detected metal soap, decomposed oil and alkaline ions by analysis of sludge. This results was proof of phenomena like oil degradation, precipitation of process materials and wear of compressor. Therefore we improved stability and lubricity of POE, reevaluated process materials and contaminations in refrigerating circuit. In this paper we discuss newly developed these technologies and evaluation results of it by life test of refrigerator.

When are solar refrigerators less costly than on-grid refrigerators: A simulation modeling study☆

PubMed Central

Haidari, Leila A.; Brown, Shawn T.; Wedlock, Patrick; Connor, Diana L.; Spiker, Marie; Lee, Bruce Y.

2017-01-01

Background Gavi recommends solar refrigerators for vaccine storage in areas with less than eight hours of electricity per day, and WHO guidelines are more conservative. The question remains: Can solar refrigerators provide value where electrical outages are less frequent? Methods Using a HERMES-generated computational model of the Mozambique routine immunization supply chain, we simulated the use of solar versus electric mains-powered refrigerators (hereafter referred to as “electric refrigerators”) at different locations in the supply chain under various circumstances. Results At their current price premium, the annual cost of each solar refrigerator is 132% more than each electric refrigerator at the district level and 241% more at health facilities. Solar refrigerators provided savings over electric refrigerators when one-day electrical outages occurred more than five times per year at either the district level or the health facilities, even when the electric refrigerator holdover time exceeded the duration of the outage. Two-day outages occurring more than three times per year at the district level or more than twice per year at the health facilities also caused solar refrigerators to be cost saving. Lowering the annual cost of a solar refrigerator to 75% more than an electric refrigerator allowed solar refrigerators to be cost saving at either level when one-day outages occurred more than once per year, or when two-day outages occurred more than once per year at the district level or even once per year at the health facilities. Conclusion Our study supports WHO and Gavi guidelines. In fact, solar refrigerators may provide savings in total cost per dose administered over electrical refrigerators when electrical outages are less frequent. Our study identified the frequency and duration at which electrical outages need to occur for solar refrigerators to provide savings in total cost per dose administered over electric refrigerators at different solar

Introduction Analysis of Refrigerating and Air-Conditioning Technologies in Micro Grid Type Food Industrial Park

NASA Astrophysics Data System (ADS)

Shimazaki, Yoichi

The aim of this study was to evaluate the refrigerating and air-conditioning technologies in cases of introducing both cogeneration system and energy network in food industrial park. The energy data of 14 factories were classified into steam, hot water, heating, cooling, refrigerating, freezing and electric power by interviews. The author developed a micro grid model based on linear programming so as to minimize the total system costs. The industrial park was divided into the 2,500 square meter mesh in order to take steam transport into consideration. Four cases were investigated. It was found that the electric power driven freezer was introduced compared with the ammonia absorption freezer. The ammonia absorption freezer was introduced in the factory that there is a little steam demand and large freezing demand at the same time.

Chemically assisted mechanical refrigeration process

DOEpatents

Vobach, Arnold R.

1987-01-01

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer (11) at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer (11) to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator (10) to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator.

Chemically assisted mechanical refrigeration process

DOEpatents

Vobach, Arnold R.

1987-01-01

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer (11) at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer (11) to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator (10) to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing he evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator.

Chemically assisted mechanical refrigeration process

DOEpatents

Vobach, A.R.

1987-06-23

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.

Chemically assisted mechanical refrigeration process

DOEpatents

Vobach, A.R.

1987-11-24

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.

Review of magnetic refrigeration system as alternative to conventional refrigeration system

NASA Astrophysics Data System (ADS)

Mezaal, N. A.; Osintsev, K. V.; Zhirgalova, T. B.

2017-10-01

The refrigeration system is one of the most important systems in industry. Developers are constantly seeking for how to avoid the damage to the environment. Magnetic refrigeration is an emerging, environment-friendly technology based on a magnetic solid that acts as a refrigerant by magneto-caloric effect (MCE). In the case of ferromagnetic materials, MCE warms as the magnetic moments of the atom are aligned by the application of a magnetic field. There are two types of magnetic phase changes that may occur at the Curie point: first order magnetic transition (FOMT) and second order magnetic transition (SOMT). The reference cycle for magnetic refrigeration is AMR (Active Magnetic Regenerative cycle), where the magnetic material matrix works both as a refrigerating medium and as a heat regenerating medium, while the fluid flowing in the porous matrix works as a heat transfer medium. Regeneration can be accomplished by blowing a heat transfer fluid in a reciprocating fashion through the regenerator made of magnetocaloric material that is alternately magnetized and demagnetized. Many magnetic refrigeration prototypes with different designs and software models have been built in different parts of the world. In this paper, the authors try to shed light on the magnetic refrigeration and show its effectiveness compared with conventional refrigeration methods.

Discussion of Refrigeration Cycle Using Carbon Dioxide as Refrigerant

NASA Astrophysics Data System (ADS)

Ji, Amin; Sun, Miming; Li, Jie; Yin, Gang; Cheng, Keyong; Zhen, Bing; Sun, Ying

Nowadays, the problem of the environment goes worse, it urges people to research and study new energy-saving and environment-friendly refrigerants, such as carbon dioxide, at present, people do research on carbon dioxide at home and abroad. This paper introduces the property of carbon dioxide as a refrigerant, sums up and analyses carbon dioxide refrigeration cycles, and points out the development and research direction in the future.

Thermoelectric refrigerator

NASA Technical Reports Server (NTRS)

Park, Brian V. (Inventor); Smith, Jr., Malcolm C. (Inventor); McGrath, Ralph D. (Inventor); Gilley, Michael D. (Inventor); Criscuolo, Lance (Inventor); Nelson, John L. (Inventor)

1996-01-01

A refrigerator is provided which combines the benefits of superinsulation materials with thermoelectric devices and phase change materials to provide an environmentally benign system that is energy efficient and can maintain relatively uniform temperatures for extended periods of time with relatively low electrical power requirements. The refrigerator includes a thermoelectric assembly having a thermoelectric device with a hot sink and a cold sink. The superinsulation materials include a plurality of vacuum panels. The refrigerator is formed from an enclosed structure having a door. The vacuum panels may be contained within the walls of the enclosed structure and the door. By mounting the thermoelectric assembly on the door, the manufacturer of the enclosed structure is simplified and the overall R rating of the refrigerator increased. Also an electrical motor and propellers may be mounted on the door to assist in the circulation of air to improve the efficiency of the cold sink and the hot sink. A propeller and/or impeller is preferably mounted within the refrigerator to assist in establishing the desired air circulation flow path.

Vaccine refrigeration

PubMed Central

McColloster, Patrick J; Martin-de-Nicolas, Andres

2014-01-01

This commentary reviews recent changes in Centers for Disease Control (CDC) vaccine storage guidelines that were developed in response to an investigative report by the Office of the Inspector General. The use of temperature data loggers with probes residing in glycol vials is advised along with storing vaccines in pharmaceutical refrigerators. These refrigerators provide good thermal distribution but can warm to 8 °C in less than one hour after the power is discontinued. Consequently, electric grid instability influences appropriate refrigerator selection and the need for power back-up. System Average Interruption Duration Index (SAIDI) values quantify this instability and can be used to formulate region-specific guidelines. A novel aftermarket refrigerator regulator with a battery back-up power supply and microprocessor control system is also described. PMID:24442209

Non-intrusive refrigerant charge indicator

DOEpatents

Mei, Viung C.; Chen, Fang C.; Kweller, Esher

2005-03-22

A non-intrusive refrigerant charge level indicator includes a structure for measuring at least one temperature at an outside surface of a two-phase refrigerant line section. The measured temperature can be used to determine the refrigerant charge status of an HVAC system, and can be converted to a pressure of the refrigerant in the line section and compared to a recommended pressure range to determine whether the system is under-charged, properly charged or over-charged. A non-intrusive method for assessing the refrigerant charge level in a system containing a refrigerant fluid includes the step of measuring a temperature at least one outside surface of a two-phase region of a refrigerant containing refrigerant line, wherein the temperature measured can be converted to a refrigerant pressure within the line section.

Mercury(II) and methyl mercury determinations in water and fish samples by using solid phase extraction and cold vapour atomic absorption spectrometry combination.

PubMed

Tuzen, Mustafa; Karaman, Isa; Citak, Demirhan; Soylak, Mustafa

2009-07-01

A method has been developed for mercury(II) and methyl mercury speciation on Staphylococcus aureus loaded Dowex Optipore V-493 micro-column in the presented work, by using cold vapour atomic absorption spectrometry. Selective and sequential elution with 0.1 molL(-1) HCl for methyl mercury and 2 molL(-1) HCl for mercury(II) were performed at the pH range of 2-6. Optimal analytical conditions including pH, amounts of biosorbent, sample volumes were investigated. The detection limits of the analytes were 2.5 ngL(-1) for Hg(II) and 1.7 ngL(-1) for methyl mercury. The capacity of biosorbent for mercury(II) and methyl mercury was 6.5 and 5.4 mgg(-1), respectively. The validation of the presented procedure is performed by the analysis of standard reference material. The speciation procedure established was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and microwave digested fish samples.

Metabolic changes associated with active water vapour absorption in the mealworm Tenebrio molitor L. (Coleoptera, Tenebrionidae): a microcalorimetric study.

PubMed

Hansen, Lars L; Westh, Peter; Wright, Jonathan C; Ramløv, Hans

2006-03-01

Water vapour absorption (WVA) is an important mechanism for water gain in several xeric insects. Theoretical calculations indicate that the energetic cost of WVA should be small (5-10% of standard metabolic rate) assuming realistic efficiencies. In this study we explored the relationship between WVA, metabolic heat flux (HFmet.) and CO2 release in larvae of Tenebrio molitor using microcalorimetry. By comparing metabolic heat flux with the catabolic rate estimated from VCO2 , we were able to differentiate anabolic and catabolic rates prior to and during WVA, while simultaneously monitoring water exchange. Three to four hours before the onset of WVA, larvae showed clear increases in HFmet. and catabolic flux, and a simultaneous decrease in anabolic flux. Following the onset of WVA, HFmet. decreased again until indistinguishable from control (non-absorbing) values. Possible factors contributing to the "preparatory phase" are discussed, including mobilization of Malpighian tubule transporters and muscular activity in the rectum. Absorbing larvae reduced the water activity of the calorimetric cell to 0.906, agreeing with gravimetric estimates of the critical equilibrium activity. Periods of movement during WVA coincided with decreased uptake fluxes, consistent with the animal's hydrostatic skeleton and the need to close the anus to generate pressure increases in the haemocoel.

10 CFR 431.62 - Definitions concerning commercial refrigerators, freezers and refrigerator-freezers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... transparent or solid doors, sliding or hinged doors, a combination of hinged, sliding, transparent, or solid... compressors, refrigerant condensers, condenser fans and motors, and factory supplied accessories. Self... more refrigerant compressors, refrigerant condensers, condenser fans and motors, and factory supplied...

Relationship between composition of mixture charged and that in circulation in an auto refrigerant cascade and a J-T refrigerator operating in liquid refrigerant supply mode

NASA Astrophysics Data System (ADS)

Sreenivas, Bura; Nayak, H. Gurudath; Venkatarathnam, G.

2017-01-01

The composition of the refrigerant mixture in circulation during steady state operation of J-T and allied refrigerators is not the same as that charged due to liquid hold up in the heat exchangers and phase separators, as well as the differential solubility of different refrigerant components in the compressor lubricating oil. The performance of refrigerators/liquefiers operating on mixed refrigerant cycles is dependent on the mixture composition. It is therefore important to charge the right mixture that results in an optimum composition in circulation during steady state operation. The relationship between the charged and circulating composition has been experimentally studied in a J-T refrigerator operating in the liquid refrigerant supply (LRS) mode and an auto refrigerant cascade refrigerator (with a phase separator) operating in the gas refrigerant supply (GRS) mode. The results of the study are presented in this work. The results show that the method presented earlier for J-T refrigerators operating in GRS mode is also applicable in the case of refrigerators studied in this work.

Refrigeration-Induced Binding of von Willebrand Factor Facilitates Fast Clearance of Refrigerated Platelets.

PubMed

Chen, Wenchun; Druzak, Samuel A; Wang, Yingchun; Josephson, Cassandra D; Hoffmeister, Karin M; Ware, Jerry; Li, Renhao

2017-12-01

Apheresis platelets for transfusion treatment are currently stored at room temperature because after refrigeration platelets are rapidly cleared on transfusion. In this study, the role of von Willebrand factor (VWF) in the clearance of refrigerated platelets is addressed. Human and murine platelets were refrigerated in gas-permeable bags at 4°C for 24 hours. VWF binding, platelet signaling events, and platelet post-transfusion recovery and survival were measured. After refrigeration, the binding of plasma VWF to platelets was drastically increased, confirming earlier studies. The binding was blocked by peptide OS1 that bound specifically to platelet glycoprotein (GP)Ibα and was absent in VWF - / - plasma. Although surface expression of GPIbα was reduced after refrigeration, refrigeration-induced VWF binding under physiological shear induced unfolding of the GPIbα mechanosensory domain on the platelet, as evidenced by increased exposure of a linear epitope therein. Refrigeration and shear treatment also induced small elevation of intracellular Ca 2+ , phosphatidylserine exposure, and desialylation of platelets, which were absent in VWF -/- platelets or inhibited by OS1, which is a monomeric 11-residue peptide (CTERMALHNLC). Furthermore, refrigerated VWF -/- platelets displayed increased post-transfusion recovery and survival than wild-type ones. Similarly, adding OS1 to transgenic murine platelets expressing only human GPIbα during refrigeration improved their post-transfusion recovery and survival. Refrigeration-induced binding of VWF to platelets facilitates their rapid clearance by inducing GPIbα-mediated signaling. Our results suggest that inhibition of the VWF-GPIbα interaction may be a potential strategy to enable refrigeration of platelets for transfusion treatment. © 2017 American Heart Association, Inc.

The Development of a Compact Refrigeration System using Metal Hydrides

NASA Astrophysics Data System (ADS)

Bae, Sang-Chul; Ogawa, Masahito; Katsuta, Masafumi

The MH refrigeration systems are regarded as important and compact ones for solving energy and environmental issues. Our purposes are to develop the compact refrigeration system for the vending machine and the show case using MH, and to attain a refrigeration temperature of 243K by using a heat source of 403∼423K. The kinetics of MH hydriding and dehydriding reactions is of importance relative to their practical use as a refrigerator system. The kinetics of the reaction between hydrogen and MHHigh (Ti0.18Zr0.84Cr1.0FeO.7Mn0.3CuO.057)has been followed in this paper. A relatively rapid absorption of hydrogen takes place for values of relative composition to about 0.3∼0.4. It is evident that a hydrogen diffusion plays a minor role during this stage, as that part of the metal not covered by hydride is always in contact with hydrogen. The direct chemical reaction between the hydrogen and the exposed metal surface is therefore postulated as the rate-controlling process. The rate of the reaction then decreases, and for values of relative composition above about 0.8, the reaction becomes slow. After the metal particles have been completely covered by a hydride layer, the transport of materials through the layer by diffusion becomes rate controlling process

Vapour Intrusion into Buildings - A Literature Review

EPA Science Inventory

This chapter provides a review of recent research on vapour intrusion of volatile organic compounds (VOCs) into buildings. The chapter builds on a report from Tillman and Weaver (2005) which reviewed the literature on vapour intrusion through 2005. Firstly, the term ‘vapour intru...

Properties of Gas Mixtures and Their Use in Mixed-Refrigerant Joule-Thomson Refrigerators

NASA Astrophysics Data System (ADS)

Luo, E.; Gong, M.; Wu, J.; Zhou, Y.

2004-06-01

The Joule-Thomson (J-T) effect has been widely used for achieving low temperatures. In the past few years, much progress has been made in better understanding the working mechanism of the refrigeration method and in developing prototypes for different applications. In this talk, there are three aspects of our research work to be discussed. First, some special thermal properties of the mixtures for achieving liquid nitrogen temperature range will be presented. Secondly, some important conclusions from the optimization of various mixed-refrigerant J-T cycles such as a simple J-T cycle and an auto-cascade mixed-refrigerant J-T cycle will be presented. Moreover, an auto-cascade, mixed-refrigerant J-T refrigerator with a special mixture capable of achieving about 50K will be mentioned. Finally, various prototypes based on the mixed-refrigerant refrigeration technology will be described. These applications include miniature J-T cryocoolers for cooling infrared detectors and high-temperature superconducting devices, cryosurgical knife for medical treatment, low-temperature refrigerators for biological storage and so forth. The on-going research work and unanswered questions for this technology will be also discussed.

Cascade Reverse Osmosis Air Conditioning System: Cascade Reverse Osmosis and the Absorption Osmosis Cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

BEETIT Project: Battelle is developing a new air conditioning system that uses a cascade reverse osmosis (RO)-based absorption cycle. Analyses show that this new cycle can be as much as 60% more efficient than vapor compression, which is used in 90% of air conditioners. Traditional vapor-compression systems use polluting liquids for a cooling effect. Absorption cycles use benign refrigerants such as water, which is absorbed in a salt solution and pumped as liquid—replacing compression of vapor. The refrigerant is subsequently separated from absorbing salt using heat for re-use in the cooling cycle. Battelle is replacing thermal separation of refrigerant withmore » a more efficient reverse osmosis process. Research has shown that the cycle is possible, but further investment will be needed to reduce the number of cascade reverse osmosis stages and therefore cost.« less

Refrigerants and environment

NASA Astrophysics Data System (ADS)

Tsvetkov, O. B.; Laptev, Yu A.

2017-11-01

The refrigeration and air-conditioning industries are important sectors of the economy and represents about 15 % of global electricity consumptions. The chlorofluorocarbons also called CFCs are a class of refrigerants containing the halogens chlorine and/or fluorine on a carbon skeleton. Because of their environmental impact the Montreal Protocol was negotiated in 1987 to limit the production of certain CFCs and hydrochlirofluorocarbons (HCFCs) in developed and developing countries. The halogenated refrigerants are depleting the ozone layer also major contribution to the greenhouse effect. To be acceptable as a refrigerant a fluid must satisfy a variety of thermodynamic criteria and should be environment friendly with zero Ozone Depletion Potential and low Global Warming Potential. The perspective of a future phase down of HFCs is considered in this report taking into account a strategy for the phase out of HCFCs and perspective of choosing of various refrigerant followed by safety issues.

Characterization of aqueous interactions of copper-doped phosphate-based glasses by vapour sorption.

PubMed

Stähli, Christoph; Shah Mohammadi, Maziar; Waters, Kristian E; Nazhat, Showan N

2014-07-01

Owing to their adjustable dissolution properties, phosphate-based glasses (PGs) are promising materials for the controlled release of bioinorganics, such as copper ions. This study describes a vapour sorption method that allowed for the investigation of the kinetics and mechanisms of aqueous interactions of PGs of the formulation 50P2O5-30CaO-(20-x)Na2O-xCuO (x=0, 1, 5 and 10mol.%). Initial characterization was performed using (31)P magic angle spinning nuclear magnetic resonance and attenuated total reflectance-Fourier transform infrared spectroscopy. Increasing CuO content resulted in chemical shifts of the predominant Q(2) NMR peak and of the (POP)as and (PO(-)) Fourier transform infrared absorptions, owing to the higher strength of the POCu bond compared to PONa. Vapour sorption and desorption were gravimetrically measured in PG powders exposed to variable relative humidity (RH). Sorption was negligible below 70% RH and increased exponentially with RH from 70 to 90%, where it exhibited a negative correlation with CuO content. Vapour sorption in 0% and 1% CuO glasses resulted in phosphate chain hydration and hydrolysis, as evidenced by protonated Q(0)(1H) and Q(1)(1H) species. Dissolution rates in deionized water showed a linear correlation (R(2)>0.99) with vapour sorption. Furthermore, cation release rates could be predicted based on dissolution rates and PG composition. The release of orthophosphate and short polyphosphate species corroborates the action of hydrolysis and was correlated with pH changes. In conclusion, the agreement between vapour sorption and routine characterization techniques in water demonstrates the potential of this method for the study of PG aqueous reactions. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Lidar observations of low-level wind reversals over the Gulf of Lion and characterization of their impact on the water vapour variability

NASA Astrophysics Data System (ADS)

Di Girolamo, Paolo; Flamant, Cyrille; Cacciani, Marco; Summa, Donato; Stelitano, Dario; Richard, Evelyne; Ducrocq, Véronique; Fourrie, Nadia; Said, Frédérique

2017-02-01

Water vapour measurements from a ground-based Raman lidar and an airborne differential absorption lidar, complemented by high resolution numerical simulations from two mesoscale models (Arome-WMED and MESO-NH), are considered to investigate transition events from Mistral/Tramontane to southerly marine flow taking place over the Gulf of Lion in Southern France in the time frame September-October 2012, during the Hydrological Cycle in the Mediterranean Experiment (HyMeX) Special Observation Period 1 (SOP1). Low-level wind reversals associated with these transitions are found to have a strong impact on water vapour transport, leading to a large variability of the water vapour vertical and horizontal distribution. The high spatial and temporal resolution of the lidar data allow to monitor the time evolution of the three-dimensional water vapour field during these transitions from predominantly northerly Mistral/Tramontane flow to a predominantly southerly flow, allowing to identify the quite sharp separation between these flows, which is also quite well captured by the mesoscale models.

Managing Refrigerant Emissions

EPA Pesticide Factsheets

Access information on EPA's efforts to address ozone layer depletion by reducing emissions of refrigerants from stationary refrigeration and air conditioning systems and motor vehicle air conditioning systems.

Studies of copper and gold vapour lasers

NASA Astrophysics Data System (ADS)

Clark, Graeme Lawrence

The work described in this thesis covers various aspects of pulsed copper and gold vapour lasers. The work is divided into four main parts : a computer model of the kinetics of the copper vapour laser discharge; construction and characterization of a copper vapour laser and a gold vapour laser system (to be used for photodynamic cancer treatment); analysis of the thermal processes occurring in the various forms of thermal insulation used in these lasers; and studies of the use of metal walls to confine a discharge plasma. The results of this work were combined in the design of the first copper vapour laser to use metal rather than an electrically insulating ceramic material for confinement of the discharge plasma. Laser action in copper vapour has been achieved in a number of metal-walled designs, with continuous lengths of metal ranging from 30 mm, in a segmented design, to 400 mm, where the discharge plasma was confined by two molybdenum tubes of this length. A theoretical explanation of the behaviour of plasmas in metal-walled discharge vessels is described.

Turbulent Humidity Fluctuations in the Convective Boundary Layer: Case Studies Using Water Vapour Differential Absorption Lidar Measurements

NASA Astrophysics Data System (ADS)

Muppa, Shravan Kumar; Behrendt, Andreas; Späth, Florian; Wulfmeyer, Volker; Metzendorf, Simon; Riede, Andrea

2016-01-01

Turbulent humidity fluctuations in the convective boundary layer (CBL) under clear-sky conditions were investigated by deriving moments up to fourth-order. High-resolution humidity measurements were collected with a water vapour differential absorption lidar system during the HD(CP)}2 Observational Prototype Experiment (HOPE). Two cases, both representing a well-developed CBL around local noon, are discussed. While the first case (from the intensive observation period (IOP) 5 on 20 April 2013) compares well with what is considered typical CBL behaviour, the second case (from IOP 6 on 24 April 2013) shows a number of non-typical characteristics. Both cases show similar capping inversions and wind shear across the CBL top. However, a major difference between both cases is the advection of a humid layer above the CBL top during IOP 6. While the variance profile of IOP 5 shows a maximum at the interfacial layer, two variance peaks are observed near the CBL top for IOP 6. A marked difference can also be seen in the third-order moment and skewness profiles: while both are negative (positive) below (above) the CBL top for IOP 5, the structure is more complex for IOP 6. Kurtosis is about three for IOP 5, whereas for IOP 6, the distribution is slightly platykurtic. We believe that the entrainment of an elevated moist layer into the CBL is responsible for the unusual findings for IOP 6, which suggests that it is important to consider the structure of residual humidity layers entrained into the CBL.

46 CFR 147.90 - Refrigerants.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Refrigerants. 147.90 Section 147.90 Shipping COAST GUARD... Special Requirements for Particular Materials § 147.90 Refrigerants. (a) Only refrigerants listed in ANSI/ASHRAE 34-78 may be carried as ships' stores. (b) Refrigerants contained in a vessel's operating system...

46 CFR 147.90 - Refrigerants.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Refrigerants. 147.90 Section 147.90 Shipping COAST GUARD... Special Requirements for Particular Materials § 147.90 Refrigerants. (a) Only refrigerants listed in ANSI/ASHRAE 34-78 may be carried as ships' stores. (b) Refrigerants contained in a vessel's operating system...

COP improvement of refrigerator/freezers, air-conditioners, and heat pumps using nonazeotropic refrigerant mixtures

NASA Technical Reports Server (NTRS)

Westra, Douglas G.

1993-01-01

With the February, 1992 announcement by President Bush to move the deadline for outlawing CFC (chloro-fluoro-carbon) refrigerants from the year 2000 to the year 1996, the refrigeration and air-conditioning industries have been accelerating their efforts to find alternative refrigerants. Many of the alternative refrigerants being evaluated require synthetic lubricants, are less efficient, and have toxicity problems. One option to developing new, alternative refrigerants is to combine existing non-CFC refrigerants to form a nonazeotropic mixture, with the concentration optimized for the given application so that system COP (Coefficient Of Performance) may be maintained or even improved. This paper will discuss the dilemma that industry is facing regarding CFC phase-out and the problems associated with CFC alternatives presently under development. A definition of nonazeotropic mixtures will be provided, and the characteristics and COP benefits of nonazeotropic refrigerant mixtures will be explained using thermodynamic principles. Limitations and disadvantages of nonazeotropic mixtures will be discussed, and example systems using such mixtures will be reviewed.

The water vapour continuum in near-infrared windows - Current understanding and prospects for its inclusion in spectroscopic databases

NASA Astrophysics Data System (ADS)

Shine, Keith P.; Campargue, Alain; Mondelain, Didier; McPheat, Robert A.; Ptashnik, Igor V.; Weidmann, Damien

2016-09-01

Spectroscopic catalogues, such as GEISA and HITRAN, do not yet include information on the water vapour continuum that pervades visible, infrared and microwave spectral regions. This is partly because, in some spectral regions, there are rather few laboratory measurements in conditions close to those in the Earth's atmosphere; hence understanding of the characteristics of the continuum absorption is still emerging. This is particularly so in the near-infrared and visible, where there has been renewed interest and activity in recent years. In this paper we present a critical review focusing on recent laboratory measurements in two near-infrared window regions (centred on 4700 and 6300 cm-1) and include reference to the window centred on 2600 cm-1 where more measurements have been reported. The rather few available measurements, have used Fourier transform spectroscopy (FTS), cavity ring down spectroscopy, optical-feedback - cavity enhanced laser spectroscopy and, in very narrow regions, calorimetric interferometry. These systems have different advantages and disadvantages. Fourier Transform Spectroscopy can measure the continuum across both these and neighbouring windows; by contrast, the cavity laser techniques are limited to fewer wavenumbers, but have a much higher inherent sensitivity. The available results present a diverse view of the characteristics of continuum absorption, with differences in continuum strength exceeding a factor of 10 in the cores of these windows. In individual windows, the temperature dependence of the water vapour self-continuum differs significantly in the few sets of measurements that allow an analysis. The available data also indicate that the temperature dependence differs significantly between different near-infrared windows. These pioneering measurements provide an impetus for further measurements. Improvements and/or extensions in existing techniques would aid progress to a full characterisation of the continuum - as an example, we

Magnetic refrigeration for maser amplifier cooling

NASA Technical Reports Server (NTRS)

Johnson, D. L.

1982-01-01

The development of a multifrequency upconverter-maser system for the DSN has created the need to develop a closed-cycle refrigerator (CCR) capable of providing more than 3 watts of refrigeration capability at 4.5 K. In addition, operating concerns such as the high cost of electrical power consumption and the loss of maser operation due to CCR failures require that improvements be made to increase the efficiency and reliability of the CCR. One refrigeration method considered is the replacement of the Joule-Thomson expansion circuit with a magnetic refrigeration. Magnetic refrigerators can provide potentially reliable and highly efficient refrigeration at a variety of temperature ranges and cooling power. The concept of magnetic refrigeration is summarized and a literature review of existing magnetic refrigerator designs which have been built and tested and that may also be considered as possibilities as a 4 K to 15 K magnetic refrigeration stage for the DSN closed-cycle refrigerator is provided.

ARTI Refrigerant Database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

The Refrigerant Database consolidates and facilitates access to information to assist industry in developing equipment using alternative refrigerants. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

Experimental Investigation of COP Using Hydro Carbon Refrigerant in a Domestic Refrigerator

NASA Astrophysics Data System (ADS)

Peyyala, Anusha; Sudheer, N. V. V. S., Dr

2017-08-01

Under the Montreal protocol 1987 researchers worked on the possibility of alternative refrigerants like Hydroflourocarbon’s [HFC’s] and Hydrocarbon’s[HC’s] to replace refrigerants Chloroflourocarbon’s [CFC’s] and Hydrochlorofluorocarbons [HCFC’s] in air-conditioning and cooling systems that are destroying the ozone layer. On October 15, 2016 one hundred and ninety plus countries including India came to an agreement called Kigali Amendment to phase out potent green house gases by 2045 there by preventing 0.5 C rise in global temperature by 2050. Under this agreement India agreed to a timeline to reduce the use of HFC’s by 85% of their baseline by 2045. HFC’s are a family of greenhouse gases that are largely used in refrigerators and air conditioners which have reduced the Ozone Depleting Potential [ODP] but increased the Global Warming Potential [GWP]. Refrigeration and its applications are important in almost all branches of industry, so engineers have to become aware of its principles, uses and limitations. Since the decade there are major changes in the choice of refrigerants due to environmental factors. This issue is on-going and new developments should be developed to decrease the environmental problems. So the aim of this paper is to present the experimental analysis of Coefficient of performance [COP] values using R134a [HFC] & R600a [HC] as Refrigerants in Domestic refrigerator using conventional and nonconventional energy sources. Based on the results, usage of R600a in domestic refrigerators will reduce the ODP and also GWP problems which fulfills the nominal requirements of human beings without any effects.

Low-temperature magnetic refrigerator

DOEpatents

Barclay, J.A.

1983-05-26

The invention relates to magnetic refrigeration and more particularly to low temperature refrigeration between about 4 and about 20 K, with an apparatus and method utilizing a belt of magnetic material passed in and out of a magnetic field with heat exchangers within and outside the field operably disposed to accomplish refrigeration.

Applicability of ASST-A helium refrigeration system for JLab End Station Refrigerator

NASA Astrophysics Data System (ADS)

Hasan, N.; Knudsen, P.; Ganni, V.

2017-12-01

The MØLLER experiment at Jefferson Lab (JLab) is a high power (5 kW) liquid hydrogen target scheduled to be operational in the 12 GeV-era. At present, cryogenic loads and targets at three of JLab’s four experimental halls are supported by the End Station Refrigerator (ESR) - a CTI/Helix 1.5 kW 4.5 K refrigerator. It is not capable of supporting the high power target load and a capacity upgrade of the ESR cryogenic system is essential. The ASST-A helium refrigeration system is a 4 kW 4.5 K refrigerator. It was designed and used for the Superconducting Super Collider Lab (SSCL) magnet string test and later obtained by JLab after the cancellation of that project. The modified ASST-A refrigeration system, which will be called ESR-II along with a support flow from JLab’s Central Helium Liquefier (CHL) is considered as an option for the End Station Refrigerator capacity upgrade. The applicability of this system for ESR-II under varying load conditions is investigated. The present paper outlines the findings of this process study.

Thermodynamic Analysis of a Mixed Refrigerant Ejector Refrigeration Cycle Operating with Two Vapor-liquid Separators

NASA Astrophysics Data System (ADS)

Tan, Yingying; Chen, Youming; Wang, Lin

2018-06-01

A mixed refrigerant ejector refrigeration cycle operating with two-stage vapor-liquid separators (MRERC2) is proposed to obtain refrigeration temperature at -40°C. The thermodynamic investigations on performance of MRERC2 using zeotropic mixture refrigerant R23/R134a are performed, and the comparisons of cycle performance between MRERC2 and MRERC1 (MRERC with one-stage vapor-liquid separator) are conducted. The results show that MRERC2 can achieve refrigeration temperature varying between -23.9°C and -42.0°C when ejector pressure ratio ranges from 1.6 to 2.3 at the generation temperature of 57.3-84.9°C. The parametric analysis indicates that increasing condensing temperature decreases coefficient of performance ( COP) of MRERC2, and increasing ejector pressure ratio and mass fraction of the low boiling point component in the mixed refrigerant can improve COP of MRERC2. The MRERC2 shows its potential in utilizing low grade thermal energy as driving power to obtain low refrigeration temperature for the ejector refrigeration cycle.

A study of alternative refrigerants for the refrigeration and air conditioning sector in Mauritius

NASA Astrophysics Data System (ADS)

Dreepaul, R. K.

2017-11-01

The most frequently used refrigerants in the refrigeration and air conditioning (RAC) sector in Mauritius are currently hydrochlorofluorocarbons (HCFC) and hydrofluorocarbons (HFC). However, because of their strong influence on global warming and the impact of HCFCs on the ozone layer, refrigerants such as ammonia (NH3), carbon dioxide (CO2) and Hydrocarbons (HC), having minimal impact on the environment, are being considered. So far, HCs have only been safely used in domestic refrigeration. Ammonia has been used mainly for industrial refrigeration whereas CO2 is still under study. In this paper, a comparative study of the various feasible alternatives is presented in a survey that was undertaken with major stake holders in the field. The retrofitting possibility of existing equipment was assessed and safety issues associated with each refrigerant were analysed. The major setback of hydrocarbons as a widely accepted refrigerant is its flammability which was considered as a major safety hazard by the majority of respondents in the survey and the main advantages are the improved equipment coefficient of performance (COP) and better TEWI factor. This resulted in a 12 % drop in energy consumption. Despite the excellent thermodynamic properties of ammonia, its use has mainly been confined to industrial refrigeration due to its toxicity. In Mauritius, the performance of ammonia in air conditioning is being evaluated on a pilot basis. The major setback of carbon dioxide as a refrigerant is the high operating pressure which is considered a safety hazard. The high initial investment cost and the lack of qualified maintenance technician is also an issue. The use of CO2 is mainly being considered in the commercial refrigeration sector.

Selection of NIR H2O absorption transitions for in-cylinder measurement of temperature in IC engines

NASA Astrophysics Data System (ADS)

Zhou, Xin; Liu, Xiang; Jeffries, Jay B.; Hanson, Ronald K.

2005-12-01

The water vapour spectrum in the 1.25-1.65 µm region is systematically analysed to find the best absorption transitions for sensitive measurement of in-cylinder gas temperature over short paths in an internal combustion engine. The strategy to select the optimum wavelength regions and absorption line combinations is developed for the time-varying pressures and temperatures expected during the compression portion of an engine cycle. We have identified 14 transitions of water vapour in this spectral region as promising for this application. From these transitions, 16 potential line pairs were considered for a wavelength-modulated absorption sensor for in-cylinder gas temperature during the compression stroke. Expected performance is modelled for the intake portion of two engine cycles that produce extreme temperature and pressure variations during compression.

Water vapour emission in vegetable fuel: absorption cell measurements and detection limits of our CO II Dial system

NASA Astrophysics Data System (ADS)

Bellecci, C.; De Leo, L.; Gaudio, P.; Gelfusa, M.; Lo Feudo, T.; Martellucci, S.; Richetta, M.

2006-09-01

Forest fires can be the cause of serious environmental and economic damages. For this reason a considerable effort has been directed toward the forest protection and fire fighting. In the early forest fire detection, Lidar technique present considerable advantages compared to the passive detection methods based on infrared cameras currently in common use, due its higher sensitivity and ability to accurately locate the fire. The combustion phase of the vegetable matter causes a great amount of water vapour emission, thus the water molecule behaviour will be studied to obtain a fire detection system ready and efficient also before the flame propagation. A first evaluation of increment of the water vapour concentration compared to standard one will be estimated by a numerical simulation. These results will be compared with the experimental measurements carried out into a cell with a CO II Dial system, burning different kinds of vegetable fuel. Our results and their comparison will be reported in this paper.

ARTI Refrigerant Database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cain, J.M.

1993-04-30

The Refrigerant Database consolidates and facilitates access to information to assist industry in developing equipment using alternative refrigerants. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included. The database identifies sources of specific information on R-32, R-123, R-124, R-125, R-134, R-134a, R-141b, R-142b, R-143a, R-152a, R-245ca, R-290 (propane), R-717 (ammonia), ethers, and others as well as azeotropic and zeotropic blends of these fluids. It addresses lubricants includingmore » alkylbenzene, polyalkylene glycol, ester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents to accelerate availability of the information and will be completed or replaced in future updates.« less

Dilution refrigeration for space applications

NASA Technical Reports Server (NTRS)

Israelsson, U. E.; Petrac, D.

1990-01-01

Dilution refrigerators are presently used routinely in ground based applications where temperatures below 0.3 K are required. The operation of a conventional dilution refrigerator depends critically on the presence of gravity. To operate a dilution refrigerator in space many technical difficulties must be overcome. Some of the anticipated difficulties are identified in this paper and possible solutions are described. A single cycle refrigerator is described conceptually that uses forces other than gravity to function and the stringent constraints imposed on the design by requiring the refrigerator to function on the earth without using gravity are elaborated upon.

Keeping Cool With Solar-Powered Refrigeration

NASA Technical Reports Server (NTRS)

2003-01-01

In the midst of developing battery-free, solar-powered refrigeration and air conditioning systems for habitats in space, David Bergeron, the team leader for NASA's Advanced Refrigerator Technology Team at Johnson Space Center, acknowledged the need for a comparable solar refrigerator that could operate in conjunction with the simple lighting systems already in place on Earth. Bergeron, a 20-year veteran in the aerospace industry, founded the company Solus Refrigeration, Inc., in 1999 to take the patented advanced refrigeration technology he co-developed with his teammate, Johnson engineer Michael Ewert, to commercial markets. Now known as SunDanzer Refrigeration, Inc., Bergeron's company is producing battery-free, photovoltaic (PV) refrigeration systems under license to NASA, and selling them globally.

High Efficiency, Low Emission Refrigeration System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, Brian A.; Sharma, Vishaldeep

Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the highmore » refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Methods for reducing refrigerant leakage and energy consumption are available, but underutilized. Further work needs to be done to reduce costs of advanced system designs to improve market utilization. In addition, refrigeration system retrofits that result in reduced energy consumption are needed since the majority of applications address retrofits rather than new stores. The retrofit market is also of most concern since it involves large-volume refrigerant systems with high leak rates. Finally, alternative refrigerants for new and retrofit applications are needed to reduce emissions and reduce the impact on the environment. The objective of this Collaborative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory and Hill Phoenix is to develop a supermarket refrigeration system that reduces greenhouse gas emissions and has 25 to 30 percent lower energy consumption than existing systems. The outcomes of this project will include the design of a low emission, high efficiency commercial refrigeration system suitable for use in current U.S. supermarkets. In addition, a prototype low emission, high efficiency supermarket refrigeration system will be produced

U.S. Residential Miscellaneous Refrigeration Products: Results from Amazon Mechanical Turk Surveys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenblatt, Jeffery B.; Young, Scott J.; Yang, Hung-Chia

Amazon Mechanical Turk was used, for the first time, to collect statistically representative survey data from U.S. households on the presence, number, type and usage of refrigerators, freezers, and various “miscellaneous” refrigeration products (wine/beverage coolers, residential icemakers and non-vapor compression refrigerators and freezers), along with household and demographic information. Such products have been poorly studied to date, with almost no information available about shipments, stocks, capacities, energy use, etc. A total of 9,981 clean survey responses were obtained from five distinct surveys deployed in 2012. General refrigeration product survey responses were weighted to demographics in the U.S. Energy Information Administration’smore » Residential Energy Consumption Survey 2009 dataset. Miscellaneous refrigeration product survey responses were weighted according to demographics of product ownership found in the general refrigeration product surveys. Model number matching for a portion of miscellaneous refrigeration product responses allowed validation of refrigeration product characteristics, which enabled more accurate estimates of the penetrations of these products in U.S. households. We estimated that there were 12.3±1.0 million wine/beverage coolers, 5.5(–3.5,+3.2) million residential icemakers and 4.4(–2.7,+2.3) million non-vapor compression refrigerators in U.S. households in 2012. (All numerical results are expressed with ranges indicating the 95% confidence interval.) No evidence was found for the existence of non-vapor compression freezers. Moreover, we found that 15% of wine/beverage coolers used vapor compression cooling technology, while 85% used thermoelectric cooling technology, with the vast majority of thermoelectric units having capacities of less than 30 wine bottles (approximately 3.5 cubic feet). No evidence was found for the existence of wine/beverage coolers with absorption cooling technology. Additionally, we

U.S. Residential Miscellaneous Refrigeration Products: Results from Amazon Mechanical Turk Surveys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenblatt, Jeffery B.; Young, Scott J.; Yang, Hung-Chia

Amazon Mechanical Turk was used, for the first time, to collect statistically representative survey data from U.S. households on the presence, number, type and usage of refrigerators, freezers, and various “miscellaneous” refrigeration products (wine/beverage coolers, residential icemakers and non-vapor compression refrigerators and freezers), along with household and demographic information. Such products have been poorly studied to date, with almost no information available about shipments, stocks, capacities, energy use, etc. A total of 9,820 clean survey responses were obtained from four distinct surveys deployed in 2012. General refrigeration product survey responses were weighted to demographics in the U.S. Energy Information Administration’smore » Residential Energy Consumption Survey 2009 dataset. Miscellaneous refrigeration product survey responses were weighted according to demographics of product ownership found in the general refrigeration product surveys. Model number matching for a portion of miscellaneous refrigeration product responses allowed validation of refrigeration product characteristics, which enabled more accurate estimates of the penetrations of these products in U.S. households. We estimated that there were 12.3±1.0 million wine/beverage coolers, 5.5(–3.5,+3.2) million residential icemakers and 2.9(–2.5,+4.5) million non-vapor compression refrigerators in U.S. households in 2012. (All numerical results are expressed with ranges indicating the 95% confidence interval.) No evidence was found for the existence of non-vapor compression freezers. Moreover, we found that 15% of wine/beverage coolers used vapor compression cooling technology, while 85% used thermoelectric cooling technology, with the vast majority of thermoelectric units having capacities of less than 30 wine bottles (approximately 3.5 cubic feet). No evidence was found for the existence of wine/beverage coolers with absorption cooling technology. Additionally, we

Refrigeration Showcases

NASA Technical Reports Server (NTRS)

1997-01-01

Through the Technology Affiliates Program at the Jet Propulsion Laboratory (JPL), valuable modifications were made to refrigerator displays built by Displaymor Manufacturing Company, Inc. By working with JPL, Displaymor could address stiffer requirements that ensure the freshness of foods. The application of the space technology meant that the small business would be able to continue to market its cases without incurring expenses that could threaten the viability of the business, and the future of several dozen jobs. Research and development improvements in air flow distribution and refrigeration coil technology contributed greatly to certifying Displaymor's showcases given the new federal regulations. These modifications resulted in a refrigerator case that will keep foods cooler, longer. Such changes maintained the openness of the display, critical to customer visibility and accessibility, impulse buying, and cross-merchandising.

A review of pulse tube refrigeration

NASA Technical Reports Server (NTRS)

Radebaugh, Ray

1990-01-01

This paper reviews the development of the three types of pulse tube refrigerators: basic, resonant, and orifice types. The principles of operation are given. It is shown that the pulse tube refrigerator is a variation of the Stirling-cycle refrigerator, where the moving displacer is substituted by a heat transfer mechanism or by an orifice to bring about the proper phase shifts between pressure and mass flow rate. A harmonic analysis with phasors is described which gives reasonable results for the refrigeration power, yet is simple enough to make clear the processes which give rise to the refrigeration. The efficiency and refrigeration power are compared with those of other refrigeration cycles. A brief review is given of the research being done at various laboratories on both one- and two-stage pulse tubes. A preliminary assessment of the role of pulse tube refrigerators is discussed.

10 CFR 431.62 - Definitions concerning commercial refrigerators, freezers and refrigerator-freezers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... functional characteristics that affect energy consumption. Commercial refrigerator, freezer, and refrigerator... formed by the plane of the door, when the equipment is viewed in cross-section; and (2) For equipment...

Laser refrigeration of hydrothermal nanocrystals in physiological media.

PubMed

Roder, Paden B; Smith, Bennett E; Zhou, Xuezhe; Crane, Matthew J; Pauzauskie, Peter J

2015-12-08

Coherent laser radiation has enabled many scientific and technological breakthroughs including Bose-Einstein condensates, ultrafast spectroscopy, superresolution optical microscopy, photothermal therapy, and long-distance telecommunications. However, it has remained a challenge to refrigerate liquid media (including physiological buffers) during laser illumination due to significant background solvent absorption and the rapid (∼ ps) nonradiative vibrational relaxation of molecular electronic excited states. Here we demonstrate that single-beam laser trapping can be used to induce and quantify the local refrigeration of physiological media by >10 °C following the emission of photoluminescence from upconverting yttrium lithium fluoride (YLF) nanocrystals. A simple, low-cost hydrothermal approach is used to synthesize polycrystalline particles with sizes ranging from <200 nm to >1 μm. A tunable, near-infrared continuous-wave laser is used to optically trap individual YLF crystals with an irradiance on the order of 1 MW/cm(2). Heat is transported out of the crystal lattice (across the solid-liquid interface) by anti-Stokes (blue-shifted) photons following upconversion of Yb(3+) electronic excited states mediated by the absorption of optical phonons. Temperatures are quantified through analysis of the cold Brownian dynamics of individual nanocrystals in an inhomogeneous temperature field via forward light scattering in the back focal plane. The cold Brownian motion (CBM) analysis of individual YLF crystals indicates local cooling by >21 °C below ambient conditions in D2O, suggesting a range of potential future applications including single-molecule biophysics and integrated photonic, electronic, and microfluidic devices.

Laser refrigeration of hydrothermal nanocrystals in physiological media

PubMed Central

Roder, Paden B.; Smith, Bennett E.; Zhou, Xuezhe; Crane, Matthew J.; Pauzauskie, Peter J.

2015-01-01

Coherent laser radiation has enabled many scientific and technological breakthroughs including Bose–Einstein condensates, ultrafast spectroscopy, superresolution optical microscopy, photothermal therapy, and long-distance telecommunications. However, it has remained a challenge to refrigerate liquid media (including physiological buffers) during laser illumination due to significant background solvent absorption and the rapid (∼ps) nonradiative vibrational relaxation of molecular electronic excited states. Here we demonstrate that single-beam laser trapping can be used to induce and quantify the local refrigeration of physiological media by >10 °C following the emission of photoluminescence from upconverting yttrium lithium fluoride (YLF) nanocrystals. A simple, low-cost hydrothermal approach is used to synthesize polycrystalline particles with sizes ranging from <200 nm to >1 μm. A tunable, near-infrared continuous-wave laser is used to optically trap individual YLF crystals with an irradiance on the order of 1 MW/cm2. Heat is transported out of the crystal lattice (across the solid–liquid interface) by anti-Stokes (blue-shifted) photons following upconversion of Yb3+ electronic excited states mediated by the absorption of optical phonons. Temperatures are quantified through analysis of the cold Brownian dynamics of individual nanocrystals in an inhomogeneous temperature field via forward light scattering in the back focal plane. The cold Brownian motion (CBM) analysis of individual YLF crystals indicates local cooling by >21 °C below ambient conditions in D2O, suggesting a range of potential future applications including single-molecule biophysics and integrated photonic, electronic, and microfluidic devices. PMID:26589813

46 CFR 154.1720 - Indirect refrigeration.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression. ...

46 CFR 154.1720 - Indirect refrigeration.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression. ...

46 CFR 154.1720 - Indirect refrigeration.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression. ...

46 CFR 154.1720 - Indirect refrigeration.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression. ...

46 CFR 154.1720 - Indirect refrigeration.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression. ...

Refrigerant leak detector

NASA Technical Reports Server (NTRS)

Byrne, E. J.

1979-01-01

Quantitative leak detector visually demonstrates refrigerant loss from precision volume of large refrigeration system over established period of time from single test point. Mechanical unit is less costly than electronic "sniffers" and is more reliable due to absence of electronic circuits that are susceptible to drift.

Quantum-circuit refrigerator

NASA Astrophysics Data System (ADS)

Tan, Kuan Yen; Partanen, Matti; Lake, Russell E.; Govenius, Joonas; Masuda, Shumpei; Möttönen, Mikko

2017-05-01

Quantum technology promises revolutionizing applications in information processing, communications, sensing and modelling. However, efficient on-demand cooling of the functional quantum degrees of freedom remains challenging in many solid-state implementations, such as superconducting circuits. Here we demonstrate direct cooling of a superconducting resonator mode using voltage-controllable electron tunnelling in a nanoscale refrigerator. This result is revealed by a decreased electron temperature at a resonator-coupled probe resistor, even for an elevated electron temperature at the refrigerator. Our conclusions are verified by control experiments and by a good quantitative agreement between theory and experimental observations at various operation voltages and bath temperatures. In the future, we aim to remove spurious dissipation introduced by our refrigerator and to decrease the operational temperature. Such an ideal quantum-circuit refrigerator has potential applications in the initialization of quantum electric devices. In the superconducting quantum computer, for example, fast and accurate reset of the quantum memory is needed.

Tropospheric water vapour isotopologue data (H216O, H218O, and HD16O) as obtained from NDACC/FTIR solar absorption spectra

NASA Astrophysics Data System (ADS)

Barthlott, Sabine; Schneider, Matthias; Hase, Frank; Blumenstock, Thomas; Kiel, Matthäus; Dubravica, Darko; García, Omaira E.; Sepúlveda, Eliezer; Mengistu Tsidu, Gizaw; Takele Kenea, Samuel; Grutter, Michel; Plaza-Medina, Eddy F.; Stremme, Wolfgang; Strong, Kim; Weaver, Dan; Palm, Mathias; Warneke, Thorsten; Notholt, Justus; Mahieu, Emmanuel; Servais, Christian; Jones, Nicholas; Griffith, David W. T.; Smale, Dan; Robinson, John

2017-01-01

We report on the ground-based FTIR (Fourier transform infrared) tropospheric water vapour isotopologue remote sensing data that have been recently made available via the database of NDACC (Network for the Detection of Atmospheric Composition Change; ftp://ftp.cpc.ncep.noaa.gov/ndacc/MUSICA/) and via doi:10.5281/zenodo.48902. Currently, data are available for 12 globally distributed stations. They have been centrally retrieved and quality-filtered in the framework of the MUSICA project (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water). We explain particularities of retrieving the water vapour isotopologue state (vertical distribution of H216O, H218O, and HD16O) and reveal the need for a new metadata template for archiving FTIR isotopologue data. We describe the format of different data components and give recommendations for correct data usage. Data are provided as two data types. The first type is best-suited for tropospheric water vapour distribution studies disregarding different isotopologues (comparison with radiosonde data, analyses of water vapour variability and trends, etc.). The second type is needed for analysing moisture pathways by means of H2O, δD-pair distributions.

Water-vapour variability within a convective boundary-layer assessed by large-eddy simulations and IHOP_2002 observations

NASA Astrophysics Data System (ADS)

Couvreux, F.; Guichard, F.; Redelsperger, J. L.; Kiemle, C.; Masson, V.; Lafore, J. P.; Flamant, C.

2005-10-01

This study presents a comprehensive analysis of the variability of water vapour in a growing convective boundary-layer (CBL) over land, highlighting the complex links between advection, convective activity and moisture heterogeneity in the boundary layer. A Large-eddy Simulation (LES) is designed, based on observations, and validated, using an independent data-set collected during the International H2O Project (IHOP 2002) fieldexperiment. Ample information about the moisture distribution in space and time, as well as other important CBL parameters are acquired by mesonet stations, balloon soundings, instruments on-board two aircraft and the DLR airborne water-vapour differential-absorption lidar. Because it can deliver two-dimensional cross-sections at high spatial resolution (140 m horizontal, 200 m vertical), the airborne lidar offers valuable insights of small-scale moisture-variability throughout the CBL. The LES is able to reproduce the development of the CBL in the morning and early afternoon, as assessed by comparisons of simulated mean profiles of key meteorological variables with sounding data. Simulated profiles of the variance of water-vapour mixing-ratio were found to be in good agreement with the lidar-derived counterparts. Finally, probability-density functions of potential temperature, vertical velocity and water-vapour mixing-ratio calculated from the LES show great consistency with those derived from aircraft in situ measurements in the middle of the CBL. Downdraughts entrained from above the CBL are governing the scale of moisture variability. Characteristic length-scales are found to be larger for water-vapour mixing-ratio than for temperature.The observed water-vapour variability exhibits contributions from different scales. The influence of the mesoscale (larger than LES domain size, i.e. 10 km) on the smaller-scale variability is assessed using LES and observations. The small-scale variability of water vapour is found to be important and to be

Characteristics of a Refrigeration Cycle Using a Zeotropic Refrigerant Mixture with a Temperature Glide Shift Heat Exchanger

NASA Astrophysics Data System (ADS)

Endoh, Kazuhiro; Matsushima, Hiroaki; Nonaka, Masayuki

HFC zeotropic refrigerant mixture R-407C is one of the promising alternatives for HCFC-22. We have found that the coefficient of performance (COP) of the refrigeration cycle using R-407C is improved by installing a temperature glide shift heat exchanger (TGSX) which takes advantage of zeotropic characteristics to an air-conditioner. We obtained the characteristics of a refrigeration cycle of experimental apparatus with comparison to those of a fundamental refrigeration cycle based on the refrigerant thermodynamic properties. We concluded that the COP improvement ratio of experimental apparatus with the TGSX to that without the TGSX is greater than that ratio which is calculated from the fundamental refrigeration cycle. This proved to be caused by the pressure loss of low pressure side which is not taken into account in the fundamental refrigeration cycle.

UTLS water vapour from SCIAMACHY limb measurementsV3.01 (2002-2012).

PubMed

Weigel, K; Rozanov, A; Azam, F; Bramstedt, K; Damadeo, R; Eichmann, K-U; Gebhardt, C; Hurst, D; Kraemer, M; Lossow, S; Read, W; Spelten, N; Stiller, G P; Walker, K A; Weber, M; Bovensmann, H; Burrows, J P

2016-01-01

The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) aboard the Envisat satellite provided measurements from August 2002 until April 2012. SCIAMACHY measured the scattered or direct sunlight using different observation geometries. The limb viewing geometry allows the retrieval of water vapour at about 10-25 km height from the near-infrared spectral range (1353-1410 nm). These data cover the upper troposphere and lower stratosphere (UTLS), a region in the atmosphere which is of special interest for a variety of dynamical and chemical processes as well as for the radiative forcing. Here, the latest data version of water vapour (V3.01) from SCIAMACHY limb measurements is presented and validated by comparisons with data sets from other satellite and in situ measurements. Considering retrieval tests and the results of these comparisons, the V3.01 data are reliable from about 11 to 23 km and the best results are found in the middle of the profiles between about 14 and 20 km. Above 20 km in the extra tropics V3.01 is drier than all other data sets. Additionally, for altitudes above about 19 km, the vertical resolution of the retrieved profile is not sufficient to resolve signals with a short vertical structure like the tape recorder. Below 14 km, SCIAMACHY water vapour V3.01 is wetter than most collocated data sets, but the high variability of water vapour in the troposphere complicates the comparison. For 14-20 km height, the expected errors from the retrieval and simulations and the mean differences to collocated data sets are usually smaller than 10 % when the resolution of the SCIAMACHY data is taken into account. In general, the temporal changes agree well with collocated data sets except for the Northern Hemisphere extratropical stratosphere, where larger differences are observed. This indicates a possible drift in V3.01 most probably caused by the incomplete treatment of volcanic aerosols in the retrieval. In all other regions a

Thermoelectric refrigerator having improved temperature stabilization means

DOEpatents

Falco, Charles M.

1982-01-01

A control system for thermoelectric refrigerators is disclosed. The thermoelectric refrigerator includes at least one thermoelectric element that undergoes a first order change at a predetermined critical temperature. The element functions as a thermoelectric refrigerator element above the critical temperature, but discontinuously ceases to function as a thermoelectric refrigerator element below the critical temperature. One example of such an arrangement includes thermoelectric refrigerator elements which are superconductors. The transition temperature of one of the superconductor elements is selected as the temperature control point of the refrigerator. When the refrigerator attempts to cool below the point, the metals become superconductors losing their ability to perform as a thermoelectric refrigerator. An extremely accurate, first-order control is realized.

Refrigerated cryogenic envelope

DOEpatents

Loudon, John D.

1976-11-16

An elongated cryogenic envelope including an outer tube and an inner tube coaxially spaced within said inner tube so that the space therebetween forms a vacuum chamber for holding a vacuum. The inner and outer tubes are provided with means for expanding or contracting during thermal changes. A shield is located in the vacuum chamber intermediate the inner and outer tubes; and, a refrigeration tube for directing refrigeration to the shield is coiled about at least a portion of the inner tube within the vacuum chamber to permit the refrigeration tube to expand or contract along its length during thermal changes within said vacuum chamber.

Direct condensation refrigerant recovery and restoration system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grant, D.C.H.

1992-03-10

This patent describes a refrigerant recovery and purification system for removing gaseous refrigerant from a disabled refrigeration unit, cleaning the refrigerant of contaminants, and converting the gaseous refrigerant to a liquid state for storage. It comprises a low pressure inlet section; a high pressure storage section; the low pressure inlet section comprising: an oil and refrigerant gas separator, including a separated oil removal means, first conduit means for connecting an inlet of the separator to the disabled refrigerant unit, a slack-sided accumulator, second conduit means connecting the separator to the slack-sided accumulator, a reclaim condenser, third conduit means connecting themore » separator and the reclaim condenser in series, an evaporator coil in the reclaim condenser connectable to a conventional operating refrigeration system for receiving a liquid refrigerant under pressure for expansion therein, the evaporator coil forming a condensing surface for condensing the refrigerant gas at near atmospheric pressure in the condenser, a liquid receiver, a reclaimed refrigerant storage tank, fourth conduit means further connecting the liquid receiver in series with the reclaim condenser, downstream thereof, means between the reclaim condenser and the liquid receiver.« less

Optimal design of solid oxide fuel cell, ammonia-water single effect absorption cycle and Rankine steam cycle hybrid system

NASA Astrophysics Data System (ADS)

Mehrpooya, Mehdi; Dehghani, Hossein; Ali Moosavian, S. M.

2016-02-01

A combined system containing solid oxide fuel cell-gas turbine power plant, Rankine steam cycle and ammonia-water absorption refrigeration system is introduced and analyzed. In this process, power, heat and cooling are produced. Energy and exergy analyses along with the economic factors are used to distinguish optimum operating point of the system. The developed electrochemical model of the fuel cell is validated with experimental results. Thermodynamic package and main parameters of the absorption refrigeration system are validated. The power output of the system is 500 kW. An optimization problem is defined in order to finding the optimal operating point. Decision variables are current density, temperature of the exhaust gases from the boiler, steam turbine pressure (high and medium), generator temperature and consumed cooling water. Results indicate that electrical efficiency of the combined system is 62.4% (LHV). Produced refrigeration (at -10 °C) and heat recovery are 101 kW and 22.1 kW respectively. Investment cost for the combined system (without absorption cycle) is about 2917 kW-1.

Transition to New Refrigerants

EPA Pesticide Factsheets

Overview page provides information on the refrigerants that motor vehicle air conditioners have used over time, with information on environmental impacts, refrigerant fitting sizes, label colors, and alternatives to ozone-depleting substances.

Breath alcohol analysis incorporating standardization to water vapour is as precise as blood alcohol analysis.

PubMed

Grubb, D; Rasmussen, B; Linnet, K; Olsson, S G; Lindberg, L

2012-03-10

A novel breath-alcohol analyzer based on the standardization of the breath alcohol concentration (BrAC) to the alveolar-air water vapour concentration has been developed and evaluated. The present study compares results with this particular breath analyzer with arterial blood alcohol concentrations (ABAC), the most relevant quantitative measure of brain alcohol exposure. The precision of analysis of alcohol in arterial blood and breath were determined as well as the agreement between ABAC and BrAC over time post-dosing. Twelve healthy volunteers were administered 0.6g alcohol/kg bodyweight via an orogastric tube. Duplicate breath and arterial blood samples were obtained simultaneously during the absorption, distribution and elimination phases of the alcohol metabolism with particular emphasis on the absorption phase. The precision of the breath analyzer was similar to the determination of blood alcohol concentration by headspace gas chromatography (CV 2.40 vs. 2.38%, p=0.43). The ABAC/BrAC ratio stabilized 30min post-dosing (2089±99; mean±SD). Before this the BrAC tended to underestimate the coexisting ABAC. In conclusion, breath alcohol analysis utilizing standardization of alcohol to water vapour was as precise as blood alcohol analysis, the present "gold standard" method. The BrAC reliably predicted the coexisting ABAC from 30min onwards after the intake of alcohol. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Status Of Sorption Cryogenic Refrigeration

NASA Technical Reports Server (NTRS)

Jones, Jack A.

1988-01-01

Report reviews sorption refrigeration. Developed for cooling infrared detectors, cryogenic research, and other advanced applications, sorption refrigerators have few moving parts, little vibration, and lifetimes of 10 years or more. Describes types of sorption stages, multistage and hybrid refrigeration systems, power requirements, cooling capacities, and advantages and disadvantages of various stages and systems.

Refrigeration system oil measurement and sampling device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, J.A.

1989-09-19

This patent describes a sampling device for use with a refrigeration system having a refrigerant and oil entrained therein. It comprises: an elongated reservoir having a stepped bore therein for receiving refrigerant and oil carried thereby. The reservoir comprising a large bore diameter upper section having an index marking the fill level of the reservoir and a small bore diameter lower section having graduation marks for oil level measurement. The upper and lower sections comprising transparent material to allow observation of the contents, first valve means for coupling the reservoir to the refrigeration system to admit liquid refrigerant to themore » reservoir, second valve means for selectively coupling the reservoir to the low pressure side of the refrigeration system or to a vacuum line to evacuate vaporized refrigerant from the reservoir, and means for supplying heat to the refrigerant in the bore to facilitate vaporization of the refrigerant.« less

Enhanced water vapour flow in silica microchannels and interdiffusive water vapour flow through anodic aluminium oxide (AAO) membranes

NASA Astrophysics Data System (ADS)

Lei, Wenwen; McKenzie, David R.

2015-12-01

Enhanced liquid water flows through carbon nanotubes reinvigorated the study of moisture permeation through membranes and micro- and nano-channels. The study of water vapour through micro-and nano-channels has been neglected even though water vapour is as important as liquid water for industry, especially for encapsulation of electronic devices. Here we measure moisture flow rates in silica microchannels and interdiffusive water vapour flows in anodic aluminium oxide (AAO) membrane channels for the first time. We construct theory for the flow rates of the dominant modes of water transport through four previously defined standard configurations and benchmark it against our new measurements. The findings show that measurements of leak behaviour made using other molecules, such as helium, are not reliable. Single phase water vapour flow is overestimated by a helium measurement, while Washburn or capillary flow is underestimated or for all channels when boundary slip applies, to an extent that depends on the slip length for the liquid phase flows.

Refrigeration for Cryogenic Sensors

NASA Technical Reports Server (NTRS)

Gasser, M. G. (Editor)

1983-01-01

Research in cryogenically cooled refrigerators is discussed. Low-power Stirling cryocoolers; spacecraft-borne long-life units; heat exchangers; performance tests; split-stirling, linear-resonant, cryogenic refrigerators; and computer models are among the topics discussed.

Atomic origins of water-vapour-promoted alloy oxidation

NASA Astrophysics Data System (ADS)

Luo, Langli; Su, Mao; Yan, Pengfei; Zou, Lianfeng; Schreiber, Daniel K.; Baer, Donald R.; Zhu, Zihua; Zhou, Guangwen; Wang, Yanting; Bruemmer, Stephen M.; Xu, Zhijie; Wang, Chongmin

2018-06-01

The presence of water vapour, intentional or unavoidable, is crucial to many materials applications, such as in steam generators, turbine engines, fuel cells, catalysts and corrosion1-4. Phenomenologically, water vapour has been noted to accelerate oxidation of metals and alloys5,6. However, the atomistic mechanisms behind such oxidation remain elusive. Through direct in situ atomic-scale transmission electron microscopy observations and density functional theory calculations, we reveal that water-vapour-enhanced oxidation of a nickel-chromium alloy is associated with proton-dissolution-promoted formation, migration, and clustering of both cation and anion vacancies. Protons derived from water dissociation can occupy interstitial positions in the oxide lattice, consequently lowering vacancy formation energy and decreasing the diffusion barrier of both cations and anions, which leads to enhanced oxidation in moist environments at elevated temperatures. This work provides insights into water-vapour-enhanced alloy oxidation and has significant implications in other material and chemical processes involving water vapour, such as corrosion, heterogeneous catalysis and ionic conduction.

Atomic origins of water-vapour-promoted alloy oxidation.

PubMed

Luo, Langli; Su, Mao; Yan, Pengfei; Zou, Lianfeng; Schreiber, Daniel K; Baer, Donald R; Zhu, Zihua; Zhou, Guangwen; Wang, Yanting; Bruemmer, Stephen M; Xu, Zhijie; Wang, Chongmin

2018-06-01

The presence of water vapour, intentional or unavoidable, is crucial to many materials applications, such as in steam generators, turbine engines, fuel cells, catalysts and corrosion 1-4 . Phenomenologically, water vapour has been noted to accelerate oxidation of metals and alloys 5,6 . However, the atomistic mechanisms behind such oxidation remain elusive. Through direct in situ atomic-scale transmission electron microscopy observations and density functional theory calculations, we reveal that water-vapour-enhanced oxidation of a nickel-chromium alloy is associated with proton-dissolution-promoted formation, migration, and clustering of both cation and anion vacancies. Protons derived from water dissociation can occupy interstitial positions in the oxide lattice, consequently lowering vacancy formation energy and decreasing the diffusion barrier of both cations and anions, which leads to enhanced oxidation in moist environments at elevated temperatures. This work provides insights into water-vapour-enhanced alloy oxidation and has significant implications in other material and chemical processes involving water vapour, such as corrosion, heterogeneous catalysis and ionic conduction.

10 CFR 431.62 - Definitions concerning commercial refrigerators, freezers and refrigerator-freezers.

Code of Federal Regulations, 2011 CFR

2011-01-01

...-section. Basic model means, with respect to commercial refrigerators, freezers, and refrigerator-freezers... 430); (2) Is not designed and marketed exclusively for medical, scientific, or research purposes; (3... standard product temperature-measuring device. Vertical Closed means equipment with hinged or sliding doors...

Influence of the nozzle angle on refrigeration performance of a gas wave refrigerator

NASA Astrophysics Data System (ADS)

Liu, P.; Zhu, Y.; Wang, H.; Zhu, C.; Zou, J.; Wu, J.; Hu, D.

2017-05-01

A gas wave refrigerator (GWR) is a novel refrigerating device that refrigerates a medium by shock waves and expansion waves generated by gas pressure energy. In a typical GWR, the injection energy losses between the nozzle and the expansion tube are essential factors which influence the refrigeration efficiency. In this study, numerical simulations are used to analyze the underlying mechanism of the injection energy losses. The results of simulations show that the vortex loss, mixing energy loss, and oblique shock wave reflection loss are the main factors contributing to the injection energy losses in the expansion tube. Furthermore, the jet angle of the gas is found to dominate the injection energy losses. Therefore, the optimum jet angle is theoretically calculated based on the velocity triangle method. The value of the optimum jet angle is found to be 4^{circ }, 8^{circ }, and 12^{circ } when the refrigeration efficiency is the first-order, second-order, and third-order maximum value over all working ranges of jet frequency, respectively. Finally, a series of experiments are conducted with the jet angle ranging from -4^{circ } to 12^{circ } at a constant expansion ratio. The results indicate the optimal jet angle obtained by the experiments is in good agreement with the calculated value. The isentropic refrigeration efficiency increased by about 4 % after the jet angle was optimized.

The ignitability of petrol vapours and potential for vapour phase explosion by use of TASER® law enforcement electronic control device.

PubMed

Clarke, C; Andrews, S P

2014-12-01

An experimental study was made of the potential of the TASER-X26™ law enforcement electronic control device to ignite petrol vapours if used by an officer to incapacitate a person soaked in petrol, or within a flammable atmosphere containing petrol vapour. Bench scale tests have shown that a wooden mannequin with pig skin covering the chest was a suitable representation of a human target. Full scale tests using the mannequin have shown that the arc from a TASER-X26™ is capable of igniting petrol/air vapours on a petrol-soaked person. Further tests in a 1/5 scale and a full scale compartment have shown that if a TASER is used within a compartment, a petrol vapour explosion (deflagration) may be achieved. It is evident from this research that if used in a flammable vapour rich environment, the device could prove fatal not only to the target but the TASER® operator as well. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

THERMODYNAMIC PROPERTIES OF SELECTED HFC REFRIGERANTS

EPA Science Inventory

Hydrofluorocarbon (HFC) refrigerants are possible alternatives to replace ozone-depleting chlorofluorocarbon and hydrochlorofluorocarbon (HCFC) refrigerants. The flammability of a proposed new refrigerant is a major consideration in assessing its utility for a particular applicat...

Using solar-powered refrigeration for vaccine storage where other sources of reliable electricity are inadequate or costly.

PubMed

McCarney, Steve; Robertson, Joanie; Arnaud, Juliette; Lorenson, Kristina; Lloyd, John

2013-12-09

Large areas of many developing countries have no grid electricity. This is a serious challenge that threatens the continuity of the vaccine cold chain. The main alternatives to electrically powered refrigerators available for many years--kerosene- and gas-driven refrigerators--are plagued by problems with gas supply interruptions, low efficiency, poor temperature control, and frequent maintenance needs. There are currently no kerosene- or gas-driven refrigerators that qualify under the minimum standards established by the World Health Organization (WHO) Performance, Quality, and Safety (PQS) system. Solar refrigeration was a promising development in the early 1980s, providing an alternative to absorption technology to meet cold chain needs in remote areas. Devices generally had strong laboratory performance data; however, experience in the field over the years has been mixed. Traditional solar refrigerators relied on relatively expensive battery systems, which have demonstrated short lives compared to the refrigerator. There are now alternatives to the battery-based systems and a clear understanding that solar refrigerator systems need to be designed, installed, and maintained by technicians with the necessary knowledge and training. Thus, the technology is now poised to be the refrigeration method of choice for the cold chain in areas with no electricity or extremely unreliable electricity (less than 4h per average day) and sufficient sunlight. This paper highlights some lessons learned with solar-powered refrigeration, and discusses some critical factors for successful introduction of solar units into immunization programs in the future including: •Sustainable financing mechanisms and incentives for health workers and technicians are in place to support long-term maintenance, repair, and replacement parts. •System design is carried out by qualified solar refrigerator professionals taking into account the conditions at installation sites. •Installation and

Potential emission savings from refrigeration and air conditioning systems by using low GWP refrigerants

DOE PAGES

Beshr, Mohamed; Aute, Vikrant; Abdelaziz, Omar; ...

2016-08-24

Refrigeration and air conditioning systems have high, negative environmental impacts due to refrigerant charge leaks from the system and their corresponding high global warming potential. Thus, many efforts are in progress to obtain suitable low GWP alternative refrigerants and more environmentally friendly systems for the future. In addition, the system’s life cycle climate performance (LCCP) is a widespread metric proposed for the evaluation of the system’s environmental impact.

Potential emission savings from refrigeration and air conditioning systems by using low GWP refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beshr, Mohamed; Aute, Vikrant; Abdelaziz, Omar

Refrigeration and air conditioning systems have high, negative environmental impacts due to refrigerant charge leaks from the system and their corresponding high global warming potential. Thus, many efforts are in progress to obtain suitable low GWP alternative refrigerants and more environmentally friendly systems for the future. In addition, the system’s life cycle climate performance (LCCP) is a widespread metric proposed for the evaluation of the system’s environmental impact.

Design of refrigeration system using refrigerant R134a for macro compartment

NASA Astrophysics Data System (ADS)

Rani, M. F. H.; Razlan, Z. M.; Shahriman, A. B.; Yong, C. K.; Harun, A.; Hashim, M. S. M.; Faizi, M. K.; Ibrahim, I.; Kamarrudin, N. S.; Saad, M. A. M.; Zunaidi, I.; Wan, W. K.; Desa, H.

2017-10-01

The main objective of this study is to analyse and design an optimum cooling system for macro compartment. Current product of the refrigerator is not specified for single function and not compact in size. Hence, a refrigeration system using refrigerant R134a is aimed to provide instant cooling in a macro compartment with sizing about 150 × 150 × 250 mm. The macro compartment is purposely designed to fit a bottle or drink can, which is then cooled to a desired drinking temperature of about 8°C within a period of 1 minute. The study is not only concerned with analysing of heat load of the macro compartment containing drink can, but also focused on determining suitable heat exchanger volume for both evaporator and condenser, calculating compressor displacement value and computing suitable resistance value of the expansion valve. Method of optimization is used to obtain the best solution of the problem. Mollier diagram is necessary in the process of developing the refrigeration system. Selection of blower is made properly to allow air circulation and to increase the flow rate for higher heat transfer rate. Property data are taken precisely from thermodynamic property tables. As the main four components, namely condenser, compressor, evaporator and expansion valve are fully developed, the refrigeration system is complete.

Airborne and satellite remote sensing of the mid-infrared water vapour continuum.

PubMed

Newman, Stuart M; Green, Paul D; Ptashnik, Igor V; Gardiner, Tom D; Coleman, Marc D; McPheat, Robert A; Smith, Kevin M

2012-06-13

Remote sensing of the atmosphere from space plays an increasingly important role in weather forecasting. Exploiting observations from the latest generation of weather satellites relies on an accurate knowledge of fundamental spectroscopy, including the water vapour continuum absorption. Field campaigns involving the Facility for Airborne Atmospheric Measurements research aircraft have collected a comprehensive dataset, comprising remotely sensed infrared radiance observations collocated with accurate measurements of the temperature and humidity structure of the atmosphere. These field measurements have been used to validate the strength of the infrared water vapour continuum in comparison with the latest laboratory measurements. The recent substantial changes to self-continuum coefficients in the widely used MT_CKD (Mlawer-Tobin-Clough-Kneizys-Davies) model between 2400 and 3200 cm(-1) are shown to be appropriate and in agreement with field measurements. Results for the foreign continuum in the 1300-2000 cm(-1) band suggest a weak temperature dependence that is not currently included in atmospheric models. A one-dimensional variational retrieval experiment is performed that shows a small positive benefit from using new laboratory-derived continuum coefficients for humidity retrievals.

Combustion dynamics of low vapour pressure nanofuel droplets

NASA Astrophysics Data System (ADS)

Pandey, Khushboo; Chattopadhyay, Kamanio; Basu, Saptarshi

2017-07-01

manifested in two frequency ranges: (i) buoyant flame flickering and (ii) auxiliary frequencies arising from high intensity secondary ejections due to bubble ruptures. Addition of alumina NPs enhances the heat absorption rate and ensures the rapid transfer of fuel parcels (detached daughter droplets) from droplet surface to flame front through secondary ejections. Therefore, average HR shows an increasing trend with particle loading rate (PLR). The perikinetic agglomeration model is used to explain the formation of gelatinous sheath during the last phase of droplet burning. Gelatinous mass formed results in bubble entrapment. SEM images of combustion precipitates show entrapped bubble cavities along with surface and sub-surface blowholes. Morphology of combustion precipitate shows a strong variation with PLRs. We have established the coupling mechanisms among heat release, shape oscillations, and secondary atomizations that underline the combustion behaviour of such low vapour pressure nanofuels.

UTLS water vapour from SCIAMACHY limb measurementsV3.01 (2002–2012)

PubMed Central

Weigel, K.; Rozanov, A.; Azam, F.; Bramstedt, K.; Damadeo, R.; Eichmann, K.-U.; Gebhardt, C.; Hurst, D.; Kraemer, M.; Lossow, S.; Read, W.; Spelten, N.; Stiller, G. P.; Walker, K. A.; Weber, M.; Bovensmann, H.; Burrows, J. P.

2017-01-01

The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) aboard the Envisat satellite provided measurements from August 2002 until April 2012. SCIAMACHY measured the scattered or direct sunlight using different observation geometries. The limb viewing geometry allows the retrieval of water vapour at about 10–25 km height from the near-infrared spectral range (1353–1410 nm). These data cover the upper troposphere and lower stratosphere (UTLS), a region in the atmosphere which is of special interest for a variety of dynamical and chemical processes as well as for the radiative forcing. Here, the latest data version of water vapour (V3.01) from SCIAMACHY limb measurements is presented and validated by comparisons with data sets from other satellite and in situ measurements. Considering retrieval tests and the results of these comparisons, the V3.01 data are reliable from about 11 to 23 km and the best results are found in the middle of the profiles between about 14 and 20 km. Above 20 km in the extra tropics V3.01 is drier than all other data sets. Additionally, for altitudes above about 19 km, the vertical resolution of the retrieved profile is not sufficient to resolve signals with a short vertical structure like the tape recorder. Below 14 km, SCIAMACHY water vapour V3.01 is wetter than most collocated data sets, but the high variability of water vapour in the troposphere complicates the comparison. For 14–20 km height, the expected errors from the retrieval and simulations and the mean differences to collocated data sets are usually smaller than 10 % when the resolution of the SCIAMACHY data is taken into account. In general, the temporal changes agree well with collocated data sets except for the Northern Hemisphere extratropical stratosphere, where larger differences are observed. This indicates a possible drift in V3.01 most probably caused by the incomplete treatment of volcanic aerosols in the retrieval. In all other regions

Method and apparatus for desuperheating refrigerant

DOEpatents

Zess, James A.; Drost, M. Kevin; Call, Charles J.

1997-01-01

The present invention is an apparatus and method for de-superheating a primary refrigerant leaving a compressor wherein a secondary refrigerant is used between the primary refrigerant to be de-superheated. Reject heat is advantageously used for heat reclaim.

Refrigeration system having dual suction port compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Guolian

A cooling system for appliances, air conditioners, and other spaces includes a compressor, and a condenser that receives refrigerant from the compressor. The system also includes an evaporator that receives refrigerant from the condenser. Refrigerant received from the condenser flows through an upstream portion of the evaporator. A first portion of the refrigerant flows to the compressor without passing through a downstream portion of the evaporator, and a second portion of the refrigerant from the upstream portion of the condenser flows through the downstream portion of the evaporator after passing through the upstream portion of the evaporator. The second portionmore » of the refrigerant flows to the compressor after passing through the downstream portion of the evaporator. The refrigeration system may be configured to cool an appliance such as a refrigerator and/or freezer, or it may be utilized in air conditioners for buildings, motor vehicles, or other such spaces.« less

46 CFR 151.40-11 - Refrigeration systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Refrigeration systems. 151.40-11 Section 151.40-11... Refrigeration systems. (a) Boiloff systems. The venting of cargo boiloff to atmosphere shall not be used as a...) Vapor compression, tank refrigeration, and secondary refrigeration systems: The required cooling...

46 CFR 151.40-11 - Refrigeration systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Refrigeration systems. 151.40-11 Section 151.40-11... Refrigeration systems. (a) Boiloff systems. The venting of cargo boiloff to atmosphere shall not be used as a...) Vapor compression, tank refrigeration, and secondary refrigeration systems: The required cooling...

46 CFR 151.40-11 - Refrigeration systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Refrigeration systems. 151.40-11 Section 151.40-11... Refrigeration systems. (a) Boiloff systems. The venting of cargo boiloff to atmosphere shall not be used as a...) Vapor compression, tank refrigeration, and secondary refrigeration systems: The required cooling...

46 CFR 151.40-11 - Refrigeration systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Refrigeration systems. 151.40-11 Section 151.40-11... Refrigeration systems. (a) Boiloff systems. The venting of cargo boiloff to atmosphere shall not be used as a...) Vapor compression, tank refrigeration, and secondary refrigeration systems: The required cooling...

46 CFR 151.40-11 - Refrigeration systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Refrigeration systems. 151.40-11 Section 151.40-11... Refrigeration systems. (a) Boiloff systems. The venting of cargo boiloff to atmosphere shall not be used as a...) Vapor compression, tank refrigeration, and secondary refrigeration systems: The required cooling...

A comparative study on the environmental impact of supermarket refrigeration systems using low GWP refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beshr, M.; Aute, V.; Sharma, V.

Supermarket refrigeration systems have high environmental impact due to their large refrigerant charge and high leak rates. Consequently, the interest in using low GWP refrigerants such as carbon dioxide (CO 2) and new refrigerant blends is increasing. In this study, an open-source Life Cycle Climate Performance (LCCP) framework is presented and used to compare the environmental impact of four supermarket refrigeration systems: a transcritical CO 2 booster system, a cascade CO 2/N-40 system, a combined secondary circuit with central DX N-40/L-40 system, and a baseline multiplex direct expansion system utilizing R-404A and N-40. The study is performed for different climatesmore » within the USA using EnergyPlus to simulate the systems' hourly performance. Finally, further analyses are presented such as parametric, sensitivity, and uncertainty analyses to study the impact of different system parameters on the LCCP.« less

A comparative study on the environmental impact of supermarket refrigeration systems using low GWP refrigerants

DOE PAGES

Beshr, M.; Aute, V.; Sharma, V.; ...

2015-04-09

Supermarket refrigeration systems have high environmental impact due to their large refrigerant charge and high leak rates. Consequently, the interest in using low GWP refrigerants such as carbon dioxide (CO 2) and new refrigerant blends is increasing. In this study, an open-source Life Cycle Climate Performance (LCCP) framework is presented and used to compare the environmental impact of four supermarket refrigeration systems: a transcritical CO 2 booster system, a cascade CO 2/N-40 system, a combined secondary circuit with central DX N-40/L-40 system, and a baseline multiplex direct expansion system utilizing R-404A and N-40. The study is performed for different climatesmore » within the USA using EnergyPlus to simulate the systems' hourly performance. Finally, further analyses are presented such as parametric, sensitivity, and uncertainty analyses to study the impact of different system parameters on the LCCP.« less

Development of Low Global Warming Potential Refrigerant Solutions for Commercial Refrigeration Systems using a Life Cycle Climate Performance Design Tool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelaziz, Omar; Fricke, Brian A; Vineyard, Edward Allan

Commercial refrigeration systems are known to be prone to high leak rates and to consume large amounts of electricity. As such, direct emissions related to refrigerant leakage and indirect emissions resulting from primary energy consumption contribute greatly to their Life Cycle Climate Performance (LCCP). In this paper, an LCCP design tool is used to evaluate the performance of a typical commercial refrigeration system with alternative refrigerants and minor system modifications to provide lower Global Warming Potential (GWP) refrigerant solutions with improved LCCP compared to baseline systems. The LCCP design tool accounts for system performance, ambient temperature, and system load; systemmore » performance is evaluated using a validated vapor compression system simulation tool while ambient temperature and system load are devised from a widely used building energy modeling tool (EnergyPlus). The LCCP design tool also accounts for the change in hourly electricity emission rate to yield an accurate prediction of indirect emissions. The analysis shows that conventional commercial refrigeration system life cycle emissions are largely due to direct emissions associated with refrigerant leaks and that system efficiency plays a smaller role in the LCCP. However, as a transition occurs to low GWP refrigerants, the indirect emissions become more relevant. Low GWP refrigerants may not be suitable for drop-in replacements in conventional commercial refrigeration systems; however some mixtures may be introduced as transitional drop-in replacements. These transitional refrigerants have a significantly lower GWP than baseline refrigerants and as such, improved LCCP. The paper concludes with a brief discussion on the tradeoffs between refrigerant GWP, efficiency and capacity.« less

46 CFR 154.702 - Refrigerated carriage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Pressure and Temperature Control § 154.702 Refrigerated carriage. (a) Each refrigeration system must: (1... the purpose of this section, a “refrigeration unit” includes a compressor and its motors and controls...

46 CFR 154.702 - Refrigerated carriage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Pressure and Temperature Control § 154.702 Refrigerated carriage. (a) Each refrigeration system must: (1... the purpose of this section, a “refrigeration unit” includes a compressor and its motors and controls...

46 CFR 154.702 - Refrigerated carriage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Pressure and Temperature Control § 154.702 Refrigerated carriage. (a) Each refrigeration system must: (1... the purpose of this section, a “refrigeration unit” includes a compressor and its motors and controls...

46 CFR 154.702 - Refrigerated carriage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Pressure and Temperature Control § 154.702 Refrigerated carriage. (a) Each refrigeration system must: (1... the purpose of this section, a “refrigeration unit” includes a compressor and its motors and controls...

46 CFR 154.702 - Refrigerated carriage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Pressure and Temperature Control § 154.702 Refrigerated carriage. (a) Each refrigeration system must: (1... the purpose of this section, a “refrigeration unit” includes a compressor and its motors and controls...

Water Vapour Effects in Mass Measurement

NASA Astrophysics Data System (ADS)

Khélifa, N.

2008-01-01

Water vapour density inside the mass comparator enclosure is a critical parameter whose fluctuations during mass weighing can lead to errors in the determination of an unknown mass. To monitor them, a method using DFB laser diode in the near infrared has been proposed and tested. Preliminary results of our observation of water vapour sorption and de-sorption processes from the walls and the mass standard are reported.

A historical look at chlorofluorocarbon refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhatti, M.S.

1999-07-01

A class of chemical compounds called chlorofluorocarbon refrigerants has been in widespread use since the 1930s in such diverse applications as refrigerants for refrigerating and air-conditioning systems, blowing agents for plastic foams, solvents for microelectronic circuitry and dry cleaning, sterilants for medical instruments, aerosol propellants for personal hygiene products and pesticides, and freezants for food. This paper describes the historical development of the chlorofluorocarbon refrigerants and gives brief biographical sketches of the inventors. 85 refs., 8 figs., 4 tabs.

SIMULATION RESULTS OF SINGLE REFRIGERANTS FOR USE IN A DUAL-CIRCUIT REFRIGERATOR/FREEZER

EPA Science Inventory

The paper reviews the refrigerant/freezer (RF) design and refrigerant selection process that is necessary to design an energy efficient RF that does not use fully halogenated chlorofluorocarbons (CFCs). EPA is interested in phasing out CFCs in RFs to minimize stratospheric ozone ...

Control system for thermoelectric refrigerator

NASA Technical Reports Server (NTRS)

Nelson, John L. (Inventor); Criscuolo, Lance (Inventor); Gilley, Michael D. (Inventor); Park, Brian V. (Inventor)

1996-01-01

Apparatus including a power supply (202) and control system is provided for maintaining the temperature within an enclosed structure (40) using thermoelectric devices (92). The apparatus may be particularly beneficial for use with a refrigerator (20) having superinsulation materials (46) and phase change materials (112) which cooperate with the thermoelectric device (92) to substantially enhance the overall operating efficiency of the refrigerator (20). The electrical power supply (202) and control system allows increasing the maximum power capability of the thermoelectric device (92) in response to increased heat loads within the refrigerator (20). The electrical power supply (202) and control system may also be used to monitor the performance of the cooling system (70) associated with the refrigerator (20).

Comprehensive Compressor Calorimeter Testing of Lower-GWP Alternative Refrigerants for Heat Pump and Medium Temperature Refrigeration Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shrestha, Som S; Sharma, Vishaldeep; Abdelaziz, Omar

In response to environmental concerns raised by the use of refrigerants with high Global Warming Potential (GWP), the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) has launched an industry-wide cooperative research program, referred to as the Low-GWP Alternative Refrigerants Evaluation Program (AREP), to identify and evaluate promising alternative refrigerants for major product categories. This paper reports one of the Oak Ridge National Laboratory (ORNL) contributions to AREP. It compares performance of alternative refrigerants to that of R-410A and R-404A for heat pump and medium temperature applications, respectively. The alternatives reported in this paper are: R-32, DR-5, and L-41a for R-410A andmore » ARM-31a, D2Y-65, L-40, and a mixture of R-32 and R-134a for R-404A. All performance comparison tests were conducted using scroll compressors of ~1.85 tons (6.5 kW) cooling capacity. Tests were conducted over a range of combinations of saturation suction and saturation discharge temperatures for both compressors. The tests showed that, in general, energy efficiency ratio (EER) and cooling capacity of R-410A alternative refrigerants were slightly lower than that of the baseline refrigerant with a moderate increases in discharge temperature. On the other hand, R-404A alternative refrigerants showed relative performance dependence on saturation suction and saturation discharge temperatures and larger increases in discharge temperature than for the R-410A alternatives. This paper summarizes the relative performance of all alternative refrigerants compared to their respective baseline.« less

High-Performance, Low Environmental Impact Refrigerants

NASA Technical Reports Server (NTRS)

McCullough, E. T.; Dhooge, P. M.; Glass, S. M.; Nimitz, J. S.

2001-01-01

Refrigerants used in process and facilities systems in the US include R-12, R-22, R-123, R-134a, R-404A, R-410A, R-500, and R-502. All but R-134a, R-404A, and R-410A contain ozone-depleting substances that will be phased out under the Montreal Protocol. Some of the substitutes do not perform as well as the refrigerants they are replacing, require new equipment, and have relatively high global warming potentials (GWPs). New refrigerants are needed that addresses environmental, safety, and performance issues simultaneously. In efforts sponsored by Ikon Corporation, NASA Kennedy Space Center (KSC), and the US Environmental Protection Agency (EPA), ETEC has developed and tested a new class of refrigerants, the Ikon (registered) refrigerants, based on iodofluorocarbons (IFCs). These refrigerants are nonflammable, have essentially zero ozone-depletion potential (ODP), low GWP, high performance (energy efficiency and capacity), and can be dropped into much existing equipment.

Magnetic refrigeration for low-temperature applications

NASA Technical Reports Server (NTRS)

Barclay, J. A.

1985-01-01

The application of refrigeration at low temperatures ranging from production of liquid helium for medical imaging systems to cooling of infrared sensors on surveillance satellites is discussed. Cooling below about 15 K with regenerative refrigerators is difficult because of the decreasing thermal mass of the regenerator compared to that of the working material. In order to overcome this difficulty with helium gas as the working material, a heat exchanger plus a Joule-Thomson or other exponder is used. Regenerative magnetic refrigerators with magnetic solids as the working material have the same regenerator problem as gas refrigerators. This problem provides motivation for the development of nonregenerative magnetic refrigerators that span approximately 1 K to approximately 0 K. Particular emphasis is placed on high reliability and high efficiency. Calculations indicate considerable promise in this area. The principles, the potential, the problems, and the progress towards development of successful 4 to 20 K magnetic refrigerators are discussed.

Refrigerant charge management in a heat pump water heater

DOEpatents

Chen, Jie; Hampton, Justin W.

2016-07-05

Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, and methods of managing refrigerant charge. Various embodiments remove idle refrigerant from a heat exchanger that is not needed for transferring heat by opening a refrigerant recovery valve and delivering the idle refrigerant from the heat exchanger to an inlet port on the compressor. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled by controlling how much refrigerant is drawn from the heat exchanger, by letting some refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and various components can be interconnected with refrigerant conduit. Some embodiments deliver refrigerant gas to the heat exchanger and drive liquid refrigerant out prior to isolating the heat exchanger.

Not all counterclockwise thermodynamic cycles are refrigerators

NASA Astrophysics Data System (ADS)

Dickerson, R. H.; Mottmann, J.

2016-06-01

Clockwise cycles on PV diagrams always represent heat engines. It is therefore tempting to assume that counterclockwise cycles always represent refrigerators. This common assumption is incorrect: most counterclockwise cycles cannot be refrigerators. This surprising result is explored here for quasi-static ideal gas cycles, and the necessary conditions for refrigeration cycles are clarified. Three logically self-consistent criteria can be used to determine if a counterclockwise cycle is a refrigerator. The most fundamental test compares the counterclockwise cycle with a correctly determined corresponding Carnot cycle. Other criteria we employ include a widely accepted description of the functional behavior of refrigerators, and a corollary to the second law that limits a refrigerator's coefficient of performance.

Sorption compressor/mechanical expander hybrid refrigeration

NASA Technical Reports Server (NTRS)

Jones, J. A.; Britcliffe, M.

1987-01-01

Experience with Deep Space Network (DSN) ground-based cryogenic refrigerators has proved the reliability of the basic two-stage Gifford-McMahon helium refrigerator. A very long life cryogenic refrigeration system appears possible by combining this expansion system or a turbo expansion system with a hydride sorption compressor in place of the usual motor driven piston compressor. To test the feasibility of this system, a commercial Gifford-McMahon refrigerator was tested using hydrogen gas as the working fluid. Although no attempt was made to optimize the system for hydrogen operation, the refrigerator developed 1.3 W at 30 K and 6.6 W at 60 K. The results of the test and of theoretical performances of the hybrid compressor coupled to these expansion systems are presented.

Magnetic refrigeration using flux compression in superconductors

NASA Technical Reports Server (NTRS)

Israelsson, U. E.; Strayer, D. M.; Jackson, H. W.; Petrac, D.

1990-01-01

The feasibility of using flux compression in high-temperature superconductors to produce the large time-varying magnetic fields required in a field cycled magnetic refrigerator operating between 20 K and 4 K is presently investigated. This paper describes the refrigerator concept and lists limitations and advantages in comparison with conventional refrigeration techniques. The maximum fields obtainable by flux compression in high-temperature supercoductor materials, as presently prepared, are too low to serve in such a refrigerator. However, reports exist of critical current values that are near usable levels for flux pumps in refrigerator applications.

Solar Refrigerators Store Life-Saving Vaccines

NASA Technical Reports Server (NTRS)

2014-01-01

Former Johnson Space Center engineer David Bergeron used his experience on the Advanced Refrigeration Technology Team to found SunDanzer Refrigeration Inc., a company specializing in solar-powered refrigerators. The company has created a battery-free unit that provides safe storage for vaccines in rural and remote areas around the world.

New method to assess the water vapour permeance of wound coverings.

PubMed

Jonkman, M F; Molenaar, I; Nieuwenhuis, P; Bruin, P; Pennings, A J

1988-05-01

A new method for assessing the permeability to water vapour of wound coverings is presented, using the evaporimeter developed by Nilsson. This new method combines the water vapour transmission rate (WVTR) and the vapour pressure difference across a wound covering in one absolute measure: the water vapour permeance (WVP). The WVP of a wound covering is the steady flow (g) of water vapour per unit (m2) area of surface in unit (h) time induced by unit (kPa) vapour pressure difference, g.m-2.h-1.kPa-1. Since the WVP of a wound covering is a more accurate measure for the permeability than the WVTR is, it facilitates the prediction of the water exchange of a wound covering in clinical situations.

Self-actuating heat switches for redundant refrigeration systems

NASA Technical Reports Server (NTRS)

Chan, Chung K. (Inventor)

1988-01-01

A dual refrigeration system for cooling a sink device is described, which automatically thermally couples the cold refrigerator to the sink device while thermally isolating the warm refrigerator from the sink device. The system includes two gas gap heat switches that each thermally couples one of the refrigerators to the sink device, and a pair of sorption pumps that are coupled through tubes to the heat switches. When the first refrigerator is operated and therefore cold, the first pump which is thermally coupled to it is also cooled and adsorbs gas to withdraw it from the second heat switch, to thereby thermally isolate the sink device from the warm second refrigerator. With the second refrigerator being warm, the second pump is also warm and desorbs gas, so the gas lies in the first switch, to close that switch and therefore thermally couple the cold first refrigerator to the sink device. Thus, the heat switches are automatically switched according to the temperature of the corresponding refrigerator.

Next Generation Refrigeration Lubricants for Low Global Warming Potential/Low Ozone Depleting Refrigeration and Air Conditioning Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hessell, Edward Thomas

The goal of this project is to develop and test new synthetic lubricants that possess high compatibility with new low ozone depleting (LOD) and low global warming potential (LGWP) refrigerants and offer improved lubricity and wear protection over current lubricant technologies. The improved compatibility of the lubricants with the refrigerants, along with improved lubricating properties, will resulted in lower energy consumption and longer service life of the refrigeration systems used in residential, commercial and industrial heating, ventilating and air-conditioning (HVAC) and refrigeration equipment.

Measurement of the Space Thermoacoustic Refrigerator Performance

DTIC Science & Technology

1990-09-01

the refrigerator was a requisite towards simplifying the process of selecting the operating frequency . The simplest method allowing for the most...LIST OF FIGURES I-1 Pulse Tube Refrigerator.............................. 3 1-2 Hofler Refrigerator.................................. 5 1-3 Acoustical...qualitative manner as did Rayleigh. The first example of an acoustic heat pump was the pulse - tube refrigerator in which Gifford and Longsworth, by applying

An Evaluation of the Environmental Impact of Different Commercial Supermarket Refrigeration Systems Using Low Global Warming Potential Refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beshr, Mohamed; Aute, Vikrant; Abdelaziz, Omar

Commercial refrigeration systems consumed 1.21 Quads of primary energy in 2010 and are known to be a major source for refrigerant charge leakage into the environment. Thus, it is important to study the environmental impact of commercial supermarket refrigeration systems and improve their design to minimize any adverse impacts. The system s Life Cycle Climate Performance (LCCP) was presented as a comprehensive metric with the aim of calculating the equivalent mass of carbon dioxide released into the atmosphere throughout its lifetime, from construction to operation and destruction. In this paper, an open source tool for the evaluation of the LCCPmore » of different air-conditioning and refrigeration systems is presented and used to compare the environmental impact of a typical multiplex direct expansion (DX) supermarket refrigeration systems based on three different refrigerants as follows: two hydrofluorocarbon (HFC) refrigerants (R-404A, and R-407F), and a low global warming potential (GWP) refrigerant (N-40). The comparison is performed in 8 US cities representing different climates. The hourly energy consumption of the refrigeration system, required for the calculation of the indirect emissions, is calculated using a widely used building energy modeling tool (EnergyPlus). A sensitivity analysis is performed to determine the impact of system charge and power plant emission factor on the LCCP results. Finally, we performed an uncertainty analysis to determine the uncertainty in total emissions for both R-404A and N-40 operated systems. We found that using low GWP refrigerants causes a considerable drop in the impact of uncertainty in the inputs related to direct emissions on the uncertainty of the total emissions of the system.« less

Medical cannabis use in Canada: vapourization and modes of delivery.

PubMed

Shiplo, Samantha; Asbridge, Mark; Leatherdale, Scott T; Hammond, David

2016-10-29

The mode of medical cannabis delivery-whether cannabis is smoked, vapourized, or consumed orally-may have important implications for its therapeutic efficacy and health risks. However, there is very little evidence on current patterns of use among Canadian medical cannabis users, particularly with respect to modes of delivery. The current study examined modes of medical cannabis delivery following regulatory changes in 2014 governing how Canadians access medical cannabis. A total of 364 approved adult Canadian medical cannabis users completed an online cross-sectional survey between April and June 2015. The survey examined patterns of medical cannabis use, modes of delivery used, and reasons for use. Participants were recruited through a convenience sample from nine Health Canada licensed producers. Using a vapourizer was the most popular mode of delivery for medical cannabis (53 %), followed by smoking a joint (47 %). The main reason for using a vapourizer was to reduce negative health consequences associated with smoking. A majority of current vapourizer users reported using a portable vapourizer (67.2 %), followed by a stationary vapourizer (41.7 %), and an e-cigarette or vape pen (19.3 %). Current use of a vapourizer was associated with fewer respiratory symptoms (AOR = 1.28, 95 % CI 1.05-1.56, p = 0.01). The findings suggest an increase in the popularity of vapourizers as the primary mode of delivery among approved medical users. Using vapourizers has the potential to prevent some of the adverse respiratory health consequences associated with smoking and may serve as an effective harm reduction method. Monitoring implications of such current and future changes to medical cannabis regulations may be beneficial to policymakers.

Corrosion inhibitor for aqueous ammonia absorption system

DOEpatents

Phillips, Benjamin A.; Whitlow, Eugene P.

1998-09-22

A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

Corrosion inhibitor for aqueous ammonia absorption system

DOEpatents

Phillips, B.A.; Whitlow, E.P.

1998-09-22

A method is described for inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425 F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25 C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425 F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer. 5 figs.

Ternary Dy-Er-Al magnetic refrigerants

DOEpatents

Gschneidner, Jr., Karl A.; Takeya, Hiroyuki

1995-07-25

A ternary magnetic refrigerant material comprising (Dy.sub.1-x Er.sub.x)Al.sub.2 for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant.

Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process

DOEpatents

Gschneidner, Jr., Karl A.; Pecharsky, Vitalij K.

1998-04-28

Active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing.

Semiconductor-based optical refrigerator

DOEpatents

Epstein, Richard I.; Edwards, Bradley C.; Sheik-Bahae, Mansoor

2002-01-01

Optical refrigerators using semiconductor material as a cooling medium, with layers of material in close proximity to the cooling medium that carries away heat from the cooling material and preventing radiation trapping. In addition to the use of semiconducting material, the invention can be used with ytterbium-doped glass optical refrigerators.

High temperature refrigerator

DOEpatents

Steyert, Jr., William A.

1978-01-01

A high temperature magnetic refrigerator which uses a Stirling-like cycle in which rotating magnetic working material is heated in zero field and adiabatically magnetized, cooled in high field, then adiabatically demagnetized. During this cycle said working material is in heat exchange with a pumped fluid which absorbs heat from a low temperature heat source and deposits heat in a high temperature reservoir. The magnetic refrigeration cycle operates at an efficiency 70% of Carnot.

Improving turbine performance by cooling inlet air using a waste heat powered ejector refrigerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kowalski, G.J.

1996-12-31

Stationary turbines are used to produce electricity in many areas of the world. Their performance is adversely affected by high ambient temperatures. Several means of reducing the turbine inlet temperature (offpeak water chiller and ice storage and absorption refrigeration systems) are being proposed as a means of increasing turbine output. In the present investigation the feasibility of increasing turbine output power by using its exhaust gases to power an ejector refrigeration system is demonstrated. The advantages of the ejector refrigeration are: it operates on a non-CFC fluid, its small number of moving parts and its small size. The analysis focusesmore » on United Technologies FT4 turbine with a base load output of 21.6 MW. It is demonstrated that the proposed system can decrease the turbine inlet temperature from 296.2 K to 277.6 K which increases the turbine output by 12.8% during periods of high ambient temperature and improves yearly averaged power output by 5.5% in a temperature climate. It is shown that the energy in the turbine exhaust has the potential of producing additional cooling beyond that required to reduce the inlet temperature.« less

Ternary Dy-Er-Al magnetic refrigerants

DOEpatents

Gschneidner, K.A. Jr.; Takeya, Hiroyuki

1995-07-25

A ternary magnetic refrigerant material comprising (Dy{sub 1{minus}x}Er{sub x})Al{sub 2} for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant. 29 figs.

SIMULATION OF NON-AZEOTROPIC REFRIGERANT MIXTURES FOR USE IN A DUAL-CIRCUIT REFRIGERATOR/FREEZER WITH COUNTERCURRENT HEAT EXCHANGES

EPA Science Inventory

The paper discusses a refrigerator/freezer (RF) system that has two complete and independent refrigeration cycles for the two compartments. It uses a non-azeotropic refrigerant mixture (NARM) in each cycle and countercurrent heat exchangers throughout. This RF is housed in a stan...

46 CFR 130.230 - Protection from refrigerants.

Code of Federal Regulations, 2014 CFR

2014-10-01

... refrigerants. (a) For each refrigeration system that exceeds 0.6 cubic meters (20 cubic feet) of storage... refrigeration equipment. (c) A complete recharge in the form of a spare charge must be carried for each self...

46 CFR 130.230 - Protection from refrigerants.

Code of Federal Regulations, 2011 CFR

2011-10-01

... refrigerants. (a) For each refrigeration system that exceeds 0.6 cubic meters (20 cubic feet) of storage... refrigeration equipment. (c) A complete recharge in the form of a spare charge must be carried for each self...

46 CFR 130.230 - Protection from refrigerants.

Code of Federal Regulations, 2013 CFR

2013-10-01

... refrigerants. (a) For each refrigeration system that exceeds 0.6 cubic meters (20 cubic feet) of storage... refrigeration equipment. (c) A complete recharge in the form of a spare charge must be carried for each self...

46 CFR 130.230 - Protection from refrigerants.

Code of Federal Regulations, 2012 CFR

2012-10-01

... refrigerants. (a) For each refrigeration system that exceeds 0.6 cubic meters (20 cubic feet) of storage... refrigeration equipment. (c) A complete recharge in the form of a spare charge must be carried for each self...

46 CFR 130.230 - Protection from refrigerants.

Code of Federal Regulations, 2010 CFR

2010-10-01

... refrigerants. (a) For each refrigeration system that exceeds 0.6 cubic meters (20 cubic feet) of storage... refrigeration equipment. (c) A complete recharge in the form of a spare charge must be carried for each self...

Recent advances in measurement of the water vapour continuum in the far-infrared spectral region

NASA Astrophysics Data System (ADS)

Green, P. D.; Newman, S. M.; Beeby, R. J.; Murray, J. E.; Pickering, J. C.; Harries, J. E.

2012-06-01

We present a new derivation of the foreign-broadened water vapour continuum in the far-infrared (far-IR) pure rotation band between 24 μm and 120 μm (85-420 cm-1) from field data collected in flight campaigns of the Continuum Absorption by Visible and IR radiation and Atmospheric Relevance (CAVIAR) project with Imperial College's Tropospheric Airborne Fourier Transform Spectrometer (TAFTS) far-IR spectro-radiometer instrument onboard the Facility for Airborne Atmospheric Measurement (FAAM) BAe-146 research aircraft; and compare this new derivation with those recently published in the literature in this spectral band. This new dataset validates the current Mlawer-Tobin-Clough-Kneizys-Davies (MT-CKD) 2.5 model parametrization above 300 cm-1, but indicates the need to strengthen the parametrization below 300 cm-1, by up to 50 per cent at 100 cm-1. Data recorded at a number of flight altitudes have allowed measurements within a wide range of column water vapour environments, greatly increasing the sensitivity of this analysis to the continuum strength.

Reducing the Carbon Footprint of Commercial Refrigeration Systems Using Life Cycle Climate Performance Analysis: From System Design to Refrigerant Options

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, Brian A; Abdelaziz, Omar; Vineyard, Edward Allan

In this paper, Life Cycle Climate Performance (LCCP) analysis is used to estimate lifetime direct and indirect carbon dioxide equivalent gas emissions of various refrigerant options and commercial refrigeration system designs, including the multiplex DX system with various hydrofluorocarbon (HFC) refrigerants, the HFC/R744 cascade system incorporating a medium-temperature R744 secondary loop, and the transcritical R744 booster system. The results of the LCCP analysis are presented, including the direct and indirect carbon dioxide equivalent emissions for each refrigeration system and refrigerant option. Based on the results of the LCCP analysis, recommendations are given for the selection of low GWP replacement refrigerantsmore » for use in existing commercial refrigeration systems, as well as for the selection of commercial refrigeration system designs with low carbon dioxide equivalent emissions, suitable for new installations.« less

Control method for mixed refrigerant based natural gas liquefier

DOEpatents

Kountz, Kenneth J.; Bishop, Patrick M.

2003-01-01

In a natural gas liquefaction system having a refrigerant storage circuit, a refrigerant circulation circuit in fluid communication with the refrigerant storage circuit, and a natural gas liquefaction circuit in thermal communication with the refrigerant circulation circuit, a method for liquefaction of natural gas in which pressure in the refrigerant circulation circuit is adjusted to below about 175 psig by exchange of refrigerant with the refrigerant storage circuit. A variable speed motor is started whereby operation of a compressor is initiated. The compressor is operated at full discharge capacity. Operation of an expansion valve is initiated whereby suction pressure at the suction pressure port of the compressor is maintained below about 30 psig and discharge pressure at the discharge pressure port of the compressor is maintained below about 350 psig. Refrigerant vapor is introduced from the refrigerant holding tank into the refrigerant circulation circuit until the suction pressure is reduced to below about 15 psig, after which flow of the refrigerant vapor from the refrigerant holding tank is terminated. Natural gas is then introduced into a natural gas liquefier, resulting in liquefaction of the natural gas.

Refrigerant charge management in a heat pump water heater

DOEpatents

Chen, Jie; Hampton, Justin W.

2014-06-24

Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, methods of managing refrigerant charge, and methods for heating and cooling a space and heating water. Various embodiments deliver refrigerant gas to a heat exchanger that is not needed for transferring heat, drive liquid refrigerant out of that heat exchanger, isolate that heat exchanger against additional refrigerant flowing into it, and operate the heat pump while the heat exchanger is isolated. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled or adjusted by controlling how much liquid refrigerant is driven from the heat exchanger, by letting refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and segments of refrigerant conduit can be interconnected with various components.

Mountain Plains Learning Experience Guide: Heating, Refrigeration, & Air Conditioning.

ERIC Educational Resources Information Center

Carey, John

This Heating, Refrigeration, and Air Conditioning course is comprised of eleven individualized units: (1) Refrigeration Tools, Materials, and Refrigerant; (2) Basic Heating and Air Conditioning; (3) Sealed System Repairs; (4) Basic Refrigeration Systems; (5) Compression Systems and Compressors; (6) Refrigeration Controls; (7) Electric Circuit…

Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process

DOEpatents

Gschneidner, K.A. Jr.; Pecharsky, V.K.

1998-04-28

Active magnetic regenerator and method using Gd{sub 5} (Si{sub x}Ge{sub 1{minus}x}){sub 4}, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd{sub 5} (Si{sub x} Ge{sub 1{minus}x}){sub 4}, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing. 27 figs.

Commercial Refrigeration: Heat Transfer Optimization and Energy Reduction, Measurement and Verification of a Liquid Refrigerant Pump System Retrofit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaul, Chris; Sheppy, Michael

This study describes the test results of a Refrigerant Pump System integrated into a commercial supermarket direct expansion (DX) vapor compression refrigeration system. The Liquid Refrigerant Pump System retrofit (patent-pending; application number 13/964,198) was introduced to NREL in August 2014 by CTA Architects Engineers.

Evaluation of balloon and satellite water vapour measurements in the Southern tropical and subtropical UTLS during the HIBISCUS campaign

NASA Astrophysics Data System (ADS)

Montoux, N.; Hauchecorne, A.; Pommereau, J.-P.; Lefèvre, F.; Durry, G.; Jones, R. L.; Rozanov, A.; Dhomse, S.; Burrows, J. P.; Morel, B.; Bencherif, H.

2009-07-01

between μSDLA and HALOE and SAGE II (of the order of -2 ppmv), SCIAMACHY, MIPAS and GOMOS (-1 ppmv) and SAOZ (-0.5 ppmv), exceed the 10% uncertainty of μSDLA, implying larger systematic errors than estimated for the various instruments. In the upper troposphere, where the water vapour concentration is highly variable, AIRS v5 appears to be the most consistent within its 25% uncertainty with balloon in-situ measurements as well as ECMWF. Most of the remote measurements show less reliability in the upper troposphere, losing sensitivity possibly because of absorption line saturation in their spectral ranges (HALOE, SAGE II and SCIAMACHY), instrument noise exceeding 100% (MIPAS) or imperfect refraction correction (GOMOS). An exception is the SAOZ-balloon, employing smaller H2O absorption bands in the troposphere.

Method and apparatus for de-superheating refrigerant

DOEpatents

Zess, J.A.; Drost, M.K.; Call, C.J.

1997-11-25

The present invention is an apparatus and method for de-superheating a primary refrigerant leaving a compressor wherein a secondary refrigerant is used between the primary refrigerant to be de-superheated. Reject heat is advantageously used for heat reclaim. 7 figs.

No sodium in the vapour plumes of Enceladus.

PubMed

Schneider, Nicholas M; Burger, Matthew H; Schaller, Emily L; Brown, Michael E; Johnson, Robert E; Kargel, Jeffrey S; Dougherty, Michele K; Achilleos, Nicholas A

2009-06-25

The discovery of water vapour and ice particles erupting from Saturn's moon Enceladus fuelled speculation that an internal ocean was the source. Alternatively, the source might be ice warmed, melted or crushed by tectonic motions. Sodium chloride (that is, salt) is expected to be present in a long-lived ocean in contact with a rocky core. Here we report a ground-based spectroscopic search for atomic sodium near Enceladus that places an upper limit on the mixing ratio in the vapour plumes orders of magnitude below the expected ocean salinity. The low sodium content of escaping vapour, together with the small fraction of salt-bearing particles, argues against a situation in which a near-surface geyser is fuelled by a salty ocean through cracks in the crust. The lack of observable sodium in the vapour is consistent with a wide variety of alternative eruption sources, including a deep ocean, a freshwater reservoir, or ice. The existing data may be insufficient to distinguish between these hypotheses.

The Oak Ridge Refrigerant Management Program

NASA Technical Reports Server (NTRS)

Kevil, Thomas H.

1995-01-01

For many years, chlorofluorocarbons (CFC's) have been used by the Department of Energy's (DOE) Oak Ridge Y-12 Plant in air conditioning and process refrigeration systems. However, Title 6 of the Clean Air Act Amendments (CAAA) and Executive Order 12843 (Procurement Requirements and Policies for Federal Agencies for Ozone Depleting Substances) signed by President Clinton require, as policy, that all federal agencies maximize their use of safe, alternate refrigerants and minimize, where economically practical, the use of Class 1 refrigerants. Unfortunately, many government facilities and industrial plants have no plan or strategy in place to make this changeover, even though their air conditioning and process refrigeration equipment may not be sustainable after CFC production ends December 31, 1995. The Y-12 Plant in Oak Ridge, Tennessee, has taken an aggressive approach to complying with the CAAA and is working with private industry and other government agencies to solve tough manufacturing and application problems associated with CFC and hydrochlorofluorocarbon (HCFC) alternatives. Y-12 was the first DOE Defense Program (DP) facility to develop a long-range Stratospheric Ozone Protection Plan for refrigerant management for compliance with the CAAA. It was also the first DOE DP facility to complete detailed engineering studies on retrofitting and replacing all air conditioning and process refrigeration equipment to enable operation with alternate refrigerants. The management plan and engineering studies are models for use by other government agencies, manufacturing plants, and private industry. This presentation identifies some of the hidden pitfalls to be encountered in the accelerated phaseout schedule of CFC's and explains how to overcome and prevent these problems. In addition, it outlines the general issues that must be considered when addressing the phase-out of ozone depleting substances and gives some 'lessons learned' by Y-12 from its Refrigerant Management

Flexible thin-film black gold membranes with ultrabroadband plasmonic nanofocusing for efficient solar vapour generation.

PubMed

Bae, Kyuyoung; Kang, Gumin; Cho, Suehyun K; Park, Wounjhang; Kim, Kyoungsik; Padilla, Willie J

2015-12-14

Solar steam generation has been achieved by surface plasmon heating with metallic nanoshells or nanoparticles, which have inherently narrow absorption bandwidth. For efficient light-to-heat conversion from a wider solar spectrum, we employ adiabatic plasmonic nanofocusing to attain both polarization-independent ultrabroadband light absorption and high plasmon dissipation loss. Here we demonstrate large area, flexible thin-film black gold membranes, which have multiscale structures of varying metallic nanoscale gaps (0-200 nm) as well as microscale funnel structures. The adiabatic nanofocusing of self-aggregated metallic nanowire bundle arrays produces average absorption of 91% at 400-2,500 nm and the microscale funnel structures lead to average reflection of 7% at 2.5-17 μm. This membrane allows heat localization within the few micrometre-thick layer and continuous water provision through micropores. We efficiently generate water vapour with solar thermal conversion efficiency up to 57% at 20 kW m(-2). This new structure has a variety of applications in solar energy harvesting, thermoplasmonics and related technologies.

Flexible thin-film black gold membranes with ultrabroadband plasmonic nanofocusing for efficient solar vapour generation

PubMed Central

Bae, Kyuyoung; Kang, Gumin; Cho, Suehyun K.; Park, Wounjhang; Kim, Kyoungsik; Padilla, Willie J.

2015-01-01

Solar steam generation has been achieved by surface plasmon heating with metallic nanoshells or nanoparticles, which have inherently narrow absorption bandwidth. For efficient light-to-heat conversion from a wider solar spectrum, we employ adiabatic plasmonic nanofocusing to attain both polarization-independent ultrabroadband light absorption and high plasmon dissipation loss. Here we demonstrate large area, flexible thin-film black gold membranes, which have multiscale structures of varying metallic nanoscale gaps (0–200 nm) as well as microscale funnel structures. The adiabatic nanofocusing of self-aggregated metallic nanowire bundle arrays produces average absorption of 91% at 400–2,500 nm and the microscale funnel structures lead to average reflection of 7% at 2.5–17 μm. This membrane allows heat localization within the few micrometre-thick layer and continuous water provision through micropores. We efficiently generate water vapour with solar thermal conversion efficiency up to 57% at 20 kW m−2. This new structure has a variety of applications in solar energy harvesting, thermoplasmonics and related technologies. PMID:26657535

Refrigerant pressurization system with a two-phase condensing ejector

DOEpatents

Bergander, Mark [Madison, CT

2009-07-14

A refrigerant pressurization system including an ejector having a first conduit for flowing a liquid refrigerant therethrough and a nozzle for accelerating a vapor refrigerant therethrough. The first conduit is positioned such that the liquid refrigerant is discharged from the first conduit into the nozzle. The ejector includes a mixing chamber for condensing the vapor refrigerant. The mixing chamber comprises at least a portion of the nozzle and transitions into a second conduit having a substantially constant cross sectional area. The condensation of the vapor refrigerant in the mixing chamber causes the refrigerant mixture in at least a portion of the mixing chamber to be at a pressure greater than that of the refrigerant entering the nozzle and greater than that entering the first conduit.

A new technique to assess dermal absorption of volatile chemicals in vitro by thermal gravimetric analysis.

PubMed

Rauma, Matias; Isaksson, Tina S; Johanson, Gunnar

2006-10-01

Potential health hazards of dermal exposure, variability in reported dermal absorption rates and potential losses from the skin by evaporation indicate a need for a simple, inexpensive and standardized procedure to measure dermal absorption and desorption of chemical substances. The aim of this study was to explore the possibility to measure dermal absorption and desorption of volatile chemicals using a new gravimetric technique, namely thermal gravimetric analysis (TGA), and trypsinated stratum corneum from pig. Changes in skin weight were readily detected before, during and after exposure to vapours of water, 2-propanol, methanol and toluene. The shape and height of the weight curves differed between the four chemicals, reflecting differences in diffusivity and partial pressure and skin:air partitioning, respectively. As the skin weight is highly sensitive to the partial pressure of volatile chemicals, including water, this technique requires carefully controlled conditions with respect to air flow, temperature, chemical vapour generation and humidity. This new technique may help in the assessment of dermal uptake of volatile chemicals. Only a small piece of skin is needed and skin integrity is not necessary, facilitating the use of human samples. The high resolution weight-time curves obtained may also help to elucidate the characteristics of absorption, desorption and diffusion of chemicals in skin.

ARTI refrigerant database. Quarterly report, March--May 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

1997-05-01

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information an older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some maymore » be added at a later date.« less

Dynamic simulation of a reverse Brayton refrigerator

NASA Astrophysics Data System (ADS)

Peng, N.; Lei, L. L.; Xiong, L. Y.; Tang, J. C.; Dong, B.; Liu, L. Q.

2014-01-01

A test refrigerator based on the modified Reverse Brayton cycle has been developed in the Chinese Academy of Sciences recently. To study the behaviors of this test refrigerator, a dynamic simulation has been carried out. The numerical model comprises the typical components of the test refrigerator: compressor, valves, heat exchangers, expander and heater. This simulator is based on the oriented-object approach and each component is represented by a set of differential and algebraic equations. The control system of the test refrigerator is also simulated, which can be used to optimize the control strategies. This paper describes all the models and shows the simulation results. Comparisons between simulation results and experimental data are also presented. Experimental validation on the test refrigerator gives satisfactory results.

Precooling of a dilution refrigerator

NASA Astrophysics Data System (ADS)

Pavlov, Valentin N.

A non-trivial system for Precooling of the dilution refrigerator for low-temperatureexperiments on an ISOL-facility is described in detail. Neither exchange gas in the vacuum jacket of the cryostat nor a demantable window in the 4K shield are used in this system. Instead of that the dilution refrigerator is supplemented with two capillaries and a heater in order to cool all low-temperature parts of the refrigerator down to start conditions. The, time of cooling depends on the total impedance of the first heat exchanger. Such system has been developed and tested in Dubna, and it is in operation.

Magnetocaloric Materials Revolutionize Refrigeration Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Momen, Ayyoub

Researchers at Oak Ridge National Laboratory have partnered with General Electric (GE) Appliances on a building technologies project to revolutionize today’s 100-year-old home refrigeration technology. Using magnetocaloric materials (MCM), they’ve eliminated the need for a vapor compression cycle, associated refrigerants, and their negative environmental impacts. The research team is currently working to determine the most effective means to transfer heat from the solid MCM, and using fluid passed through high-resolution microchannels shows promise. This technology has the potential to reduce energy consumption by 25%, and GE hopes to commercialize magnetocaloric refrigerators for use in homes by 2020.

EVALUATION OF OZONE-FRIENDLY HYDROFLUOROPROPANE-BASED ZEOTROPIC REFRIGERANT MIXTURES IN A LORENZ-MEUTZNER REFRIGERATOR/FREEZER

EPA Science Inventory

The two-evaporator (located in the freezer and fresh food compartments) design of the Lorenz-Meutzner (L-M) refrigerator/freezer (R/F) makes it a leading candidate for use of zeotropic refrigerant mixtures. Zeotrophic mixtures can have significant temperature glides during evapor...

Manganese Nitride Sorption Joule-Thomson Refrigerator

NASA Technical Reports Server (NTRS)

Jones, Jack A.; Phillips, Wayne M.

1992-01-01

Proposed sorption refrigeration system of increased power efficiency combines MnxNy sorption refrigeration stage with systems described in "Regenerative Sorption Refrigerator" (NPO-17630). Measured pressure-vs-composition isotherms for reversible chemisorption of N2 in MnxNy suggest feasibility to incorporate MnxNy chemisorption stage in Joule-Thomson cryogenic system. Discovery represents first known reversible nitrogen chemisorption compression system. Has potential in nitrogen-isotope separation, nitrogen purification, or contamination-free nitrogen compression.

Intercomparison of TCCON and MUSICA Water Vapour Products

NASA Astrophysics Data System (ADS)

Weaver, D.; Strong, K.; Deutscher, N. M.; Schneider, M.; Blumenstock, T.; Robinson, J.; Notholt, J.; Sherlock, V.; Griffith, D. W. T.; Barthlott, S.; García, O. E.; Smale, D.; Palm, M.; Jones, N. B.; Hase, F.; Kivi, R.; Ramos, Y. G.; Yoshimura, K.; Sepúlveda, E.; Gómez-Peláez, Á. J.; Gisi, M.; Kohlhepp, R.; Warneke, T.; Dohe, S.; Wiegele, A.; Christner, E.; Lejeune, B.; Demoulin, P.

2014-12-01

We present an intercomparison between the water vapour products from the Total Carbon Column Observing Network (TCCON) and the MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water (MUSICA), two datasets from ground-based Fourier Transform InfraRed (FTIR) spectrometers with good global representation. Where possible, comparisons to radiosondes are also included. The near-infrared TCCON measurements are optimized to provide precise monitoring of greenhouse gases for carbon cycle studies; however, TCCON's retrievals also produce water vapour products. The mid-infrared MUSICA products result from retrievals optimized to give precise and accurate information about H2O, HDO, and δD. The MUSICA water vapour products have been validated by extensive intercomparisons with H2O and δD in-situ measurements made from ground, radiosonde, and aircraft (Schneider et al. 2012, 2014), as well as by intercomparisons with satellite-based H2O and δD remote sensing measurements (Wiegele et al., 2014). This dataset provides a valuable reference point for other measurements of water vapour. This study is motivated by the limited intercomparisons performed for TCCON water vapour products and limited characterisation of their uncertainties. We compare MUSICA and TCCON products to assess the potential for TCCON measurements to contribute to studies of the water cycle, water vapour's role in climate and use as a tracer for atmospheric dynamics, and to evaluate the performance of climate models. The TCCON and MUSICA products result from measurements taken using the same FTIR instruments, enabling a comparison with constant instrumentation. The retrieval techniques differ, however, in their method and a priori information. We assess the impact of these differences and characterize the comparability of the TCCON and MUSICA datasets.

Dilution Refrigerator for Nuclear Refrigeration and Cryogenic Thermometry Studies

NASA Astrophysics Data System (ADS)

Nakagawa, Hisashi; Hata, Tohru

2014-07-01

This study explores the design and construction of an ultra-low temperature facility in order to realize the Provisional low-temperature scale from 0.9 mK to 1 K (PLTS-2000) in Japan, to disseminate its use through calibration services, and to study thermometry at low temperatures below 1 K. To this end, a dilution refrigerator was constructed in-house that has four sintered silver discrete heat exchangers for use as a precooling stage of a copper nuclear demagnetization stage. A melting curve thermometer attached to the mixing chamber flange could be cooled continuously to 4.0 mK using the refrigerator. The dependence of minimum temperatures on circulation rates can be explained by the calculation of Frossati's formula based on a perfect continuous counterflow heat exchanger model, assuming that the Kapitza resistance has a temperature dependence. Residual heat leakage to the mixing chamber was estimated to be around 86 nW. A nuclear demagnetization cryostat with a nuclear stage containing an effective amount of copper (51 mol in a 9 T magnetic field) is under construction, and we will presently start to work toward the realization of the PLTS-2000. In this article, the design and performance of the dilution refrigerator are reported.

Combined refrigeration system with a liquid pre-cooling heat exchanger

DOEpatents

Gaul, Christopher J.

2003-07-01

A compressor-pump unit for use in a vapor-compression refrigeration system is provided. The compressor-pump unit comprises a driving device including a rotatable shaft. A compressor is coupled with a first portion of the shaft for compressing gaseous refrigerant within the vapor-compression refrigeration system. A liquid pump is coupled with a second portion of the shaft for receiving liquid refrigerant having a first pressure and for discharging the received liquid refrigerant at a second pressure with the second pressure being higher than the first pressure by a predetermined amount such that the discharged liquid refrigerant is subcooled. A pre-cooling circuit is connected to the liquid pump with the pre-cooling circuit being exposed to the gaseous refrigerant whereby the gaseous refrigerant absorbs heat from the liquid refrigerant, prior to the liquid refrigerant entering the liquid pump.

Optical Refrigeration

DTIC Science & Technology

2007-12-01

confined to either glasses and crystals doped with rare-earth (RE) elements or direct-bandgap semiconductors such as gallium arsenide. Although laser...condition. Highly controlled epitaxial growth techniques, such as metal–organic chemical vapour deposition (MOCVD) can produce very low surface

Krypton based adsorption type cryogenic refrigerator

NASA Technical Reports Server (NTRS)

Jones, Jack A. (Inventor); Schember, Helene R. (Inventor)

1989-01-01

Krypton and a monolithic porous carbon such as Saran carbon are used respectively as the sorbate and sorbent of an adsorption type refrigerator to improve refrigeration efficiency and operational longevity.

REFRIGERATION ESPECIALLY FOR VERY LOW TEMPERATURES

DOEpatents

Kennedy, P.B.; Smith, H.R. Jr.

1960-09-13

A refrigeration system for producing very low temperatures is described. The system of the invention employs a binary mixture refrigerant in a closed constant volume, e.g., Freon and ethylene. Such mixture is compressed in the gaseous state and is then separated in a fractionating column element of the system. Thenceforth, the first liquid to separate is employed stagewise to cool and liq uefy successive portions of the refrigerant at successively lower temperatures by means of heat exchangers coupled between the successive stages. When shut down, all of the volumes of the system are interconnected and a portion of the refrigerant remains liquid at ambient temperatures so that no dangerous overpressures develop. The system is therefore rugged, simple and dependable in operation.

The millennium water vapour drop in chemistry-climate model simulations

NASA Astrophysics Data System (ADS)

Brinkop, Sabine; Dameris, Martin; Jöckel, Patrick; Garny, Hella; Lossow, Stefan; Stiller, Gabriele

2016-07-01

This study investigates the abrupt and severe water vapour decline in the stratosphere beginning in the year 2000 (the "millennium water vapour drop") and other similarly strong stratospheric water vapour reductions by means of various simulations with the state-of-the-art Chemistry-Climate Model (CCM) EMAC (ECHAM/MESSy Atmospheric Chemistry Model). The model simulations differ with respect to the prescribed sea surface temperatures (SSTs) and whether nudging is applied or not. The CCM EMAC is able to most closely reproduce the signature and pattern of the water vapour drop in agreement with those derived from satellite observations if the model is nudged. Model results confirm that this extraordinary water vapour decline is particularly obvious in the tropical lower stratosphere and is related to a large decrease in cold point temperature. The drop signal propagates under dilution to the higher stratosphere and to the poles via the Brewer-Dobson circulation (BDC). We found that the driving forces for this significant decline in water vapour mixing ratios are tropical sea surface temperature (SST) changes due to a coincidence with a preceding strong El Niño-Southern Oscillation event (1997/1998) followed by a strong La Niña event (1999/2000) and supported by the change of the westerly to the easterly phase of the equatorial stratospheric quasi-biennial oscillation (QBO) in 2000. Correct (observed) SSTs are important for triggering the strong decline in water vapour. There are indications that, at least partly, SSTs contribute to the long period of low water vapour values from 2001 to 2006. For this period, the specific dynamical state of the atmosphere (overall atmospheric large-scale wind and temperature distribution) is important as well, as it causes the observed persistent low cold point temperatures. These are induced by a period of increased upwelling, which, however, has no corresponding pronounced signature in SSTs anomalies in the tropics. Our free

Absorption heat pump for space applications

NASA Technical Reports Server (NTRS)

Nguyen, Tuan; Simon, William E.; Warrier, Gopinath R.; Woramontri, Woranun

1993-01-01

In the first part, the performance of the Absorption Heat Pump (AHP) with water-sulfuric acid and water-magnesium chloride as two new refrigerant-absorbent fluid pairs was investigated. A model was proposed for the analysis of the new working pairs in a heat pump system, subject to different temperature lifts. Computer codes were developed to calculate the Coefficient of Performance (COP) of the system with the thermodynamic properties of the working fluids obtained from the literature. The study shows the potential of water-sulfuric acid as a satisfactory replacement for water-lithium bromide in the targeted temperature range. The performance of the AHP using water-magnesium chloride as refrigerant-absorbent pair does not compare well with those obtained using water-lithium bromide. The second part concentrated on the design and testing of a simple ElectroHydrodynamic (EHD) Pump. A theoretical design model based on continuum electromechanics was analyzed to predict the performance characteristics of the EHD pump to circulate the fluid in the absorption heat pump. A numerical method of solving the governing equations was established to predict the velocity profile, pressure - flow rate relationship and efficiency of the pump. The predicted operational characteristics of the EHD pump is comparable to that of turbomachinery hardware; however, the overall efficiency of the electromagnetic pump is much lower. An experimental investigation to verify the numerical results was conducted. The pressure - flow rate performance characteristics and overall efficiency of the pump obtained experimentally agree well with the theoretical model.

Water vapour retrieval using the Precision Solar Spectroradiometer

NASA Astrophysics Data System (ADS)

Raptis, Panagiotis-Ioannis; Kazadzis, Stelios; Gröbner, Julian; Kouremeti, Natalia; Doppler, Lionel; Becker, Ralf; Helmis, Constantinos

2018-02-01

The Precision Solar Spectroradiometer (PSR) is a new spectroradiometer developed at Physikalisch-Meteorologisches Observatorium Davos - World Radiation Center (PMOD-WRC), Davos, measuring direct solar irradiance at the surface, in the 300-1020 nm spectral range and at high temporal resolution. The purpose of this work is to investigate the instrument's potential to retrieve integrated water vapour (IWV) using its spectral measurements. Two different approaches were developed in order to retrieve IWV: the first one uses single-channel and wavelength measurements, following a theoretical water vapour high absorption wavelength, and the second one uses direct sun irradiance integrated at a certain spectral region. IWV results have been validated using a 2-year data set, consisting of an AERONET sun-photometer Cimel CE318, a Global Positioning System (GPS), a microwave radiometer profiler (MWP) and radiosonde retrievals recorded at Meteorological Observatorium Lindenberg, Germany. For the monochromatic approach, better agreement with retrievals from other methods and instruments was achieved using the 946 nm channel, while for the spectral approach the 934-948 nm window was used. Compared to other instruments' retrievals, the monochromatic approach leads to mean relative differences up to 3.3 % with the coefficient of determination (R2) being in the region of 0.87-0.95, while for the spectral approach mean relative differences up to 0.7 % were recorded with R2 in the region of 0.96-0.98. Uncertainties related to IWV retrieval methods were investigated and found to be less than 0.28 cm for both methods. Absolute IWV deviations of differences between PSR and other instruments were determined the range of 0.08-0.30 cm and only in extreme cases would reach up to 15 %.

Energy Efficient Operation of Ammonia Refrigeration Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohammed, Abdul Qayyum; Wenning, Thomas J; Sever, Franc

Ammonia refrigeration systems typically offer many energy efficiency opportunities because of their size and complexity. This paper develops a model for simulating single-stage ammonia refrigeration systems, describes common energy saving opportunities, and uses the model to quantify those opportunities. The simulation model uses data that are typically available during site visits to ammonia refrigeration plants and can be calibrated to actual consumption and performance data if available. Annual electricity consumption for a base-case ammonia refrigeration system is simulated. The model is then used to quantify energy savings for six specific energy efficiency opportunities; reduce refrigeration load, increase suction pressure, employmore » dual suction, decrease minimum head pressure set-point, increase evaporative condenser capacity, and reclaim heat. Methods and considerations for achieving each saving opportunity are discussed. The model captures synergistic effects that result when more than one component or parameter is changed. This methodology represents an effective method to model and quantify common energy saving opportunities in ammonia refrigeration systems. The results indicate the range of savings that might be expected from common energy efficiency opportunities.« less

Evaluation for Practical Application of HFC Refrigerants

NASA Astrophysics Data System (ADS)

Uemura, Shigehiro; Noguchi, Masahiro; Inagaki, Sadayasu; Teraoka, Takuya

Production restriction of CFCs which are used for refrigerators and air conditioners has been implemented through the international mutual agreement approved by the Montreal Protocol. Due to the less impact on the ozone layer dep1etion, alternative refrigerants for CFCs had included HCFC-123 and HCFC-22. However, H CFC-123 and HCFC-22 do not completely prevent the ozone layer depletion. This paper presents the investigation results of HFC-125, H FC-143a, HFC-152a, and HFC-32 which prevent the ozone layer depletion and are candidates for alternatives of CFCs and HCFCs. The test results of thermal stability of these refrigerants are similar to those of CFC-12 and HCFC-22. The test results show that each refrigerant has different material compatibility. The test results of lubricant solubility show that synthetic oi1s are soluble in these refrigerants, but the mineral oils currently in use for CFCs and HCFCs are not. The refrigeration performance based on the calculated thermodynamic properties corresponds with that of the experimental results.

Health effects among refrigeration repair workers exposed to fluorocarbons.

PubMed Central

Campbell, D D; Lockey, J E; Petajan, J; Gunter, B J; Rom, W N

1986-01-01

Refrigeration repair workers may be intermittently exposed to fluorocarbons and their thermal decomposition products. A case of peripheral neuropathy (distal axonopathy) in a commercial refrigeration repairman prompted an epidemiological investigation of the health of refrigeration repair workers. No additional cases of peripheral neuropathy were identified among the 27 refrigeration repair workers studied. A reference group of 14 non-refrigeration repair workers was also studied. No differences were noted between groups for the ulnar (motor and sensory), median (motor and sensory), peroneal, sural, or tibial nerve conduction velocities. Refrigeration repair workers reported palpitations and lightheadedness significantly more often than workers in the reference group. No clinical neurological or electroneurophysiological abnormalities were detected in eight refrigeration repair workers followed up for three years during continuous employment. PMID:3004555

The early summertime Saharan heat low: sensitivity of the radiation budget and atmospheric heating to water vapour and dust aerosol

NASA Astrophysics Data System (ADS)

Alamirew, Netsanet K.; Todd, Martin C.; Ryder, Claire L.; Marsham, John H.; Wang, Yi

2018-01-01

The Saharan heat low (SHL) is a key component of the west African climate system and an important driver of the west African monsoon across a range of timescales of variability. The physical mechanisms driving the variability in the SHL remain uncertain, although water vapour has been implicated as of primary importance. Here, we quantify the independent effects of variability in dust and water vapour on the radiation budget and atmospheric heating of the region using a radiative transfer model configured with observational input data from the Fennec field campaign at the location of Bordj Badji Mokhtar (BBM) in southern Algeria (21.4° N, 0.9° E), close to the SHL core for June 2011. Overall, we find dust aerosol and water vapour to be of similar importance in driving variability in the top-of-atmosphere (TOA) radiation budget and therefore the column-integrated heating over the SHL (˜ 7 W m-2 per standard deviation of dust aerosol optical depth - AOD). As such, we infer that SHL intensity is likely to be similarly enhanced by the effects of dust and water vapour surge events. However, the details of the processes differ. Dust generates substantial radiative cooling at the surface (˜ 11 W m-2 per standard deviation of dust AOD), presumably leading to reduced sensible heat flux in the boundary layer, which is more than compensated by direct radiative heating from shortwave (SW) absorption by dust in the dusty boundary layer. In contrast, water vapour invokes a radiative warming at the surface of ˜ 6 W m-2 per standard deviation of column-integrated water vapour in kg m-2. Net effects involve a pronounced net atmospheric radiative convergence with heating rates on average of 0.5 K day-1 and up to 6 K day-1 during synoptic/mesoscale dust events from monsoon surges and convective cold-pool outflows (haboobs). On this basis, we make inferences on the processes driving variability in the SHL associated with radiative and advective heating/cooling. Depending

Magnetocaloric Materials Revolutionize Refrigeration Technology

ScienceCinema

Momen, Ayyoub

2018-06-25

Researchers at Oak Ridge National Laboratory have partnered with General Electric (GE) Appliances on a building technologies project to revolutionize today’s 100-year-old home refrigeration technology. Using magnetocaloric materials (MCM), they’ve eliminated the need for a vapor compression cycle, associated refrigerants, and their negative environmental impacts. The research team is currently working to determine the most effective means to transfer heat from the solid MCM, and using fluid passed through high-resolution microchannels shows promise. This technology has the potential to reduce energy consumption by 25%, and GE hopes to commercialize magnetocaloric refrigerators for use in homes by 2020.

ALTERNATIVE TECHNOLOGIES FOR REFRIGERATION AND AIR-CONDITIONING APPLICATIONS

EPA Science Inventory

The report gives results of an assessment of refrigeration technologies that are alternatives to vapor compression refrigeration for use in five application categories: domestic air conditioning, commercial air conditioning, mobile air conditioning, domestic refrigeration, and co...

Education in Helium Refrigeration

NASA Astrophysics Data System (ADS)

Gistau Baguer, G. M.

2004-06-01

On the one hand, at the end of the time I was active in helium refrigeration, I noticed that cryogenics was stepping into places where it was not yet used. For example, a conventional accelerator, operating at room temperature, was to be upgraded to reach higher particle energy. On the other hand, I was a little bit worried to let what I had so passionately learned during these years to be lost. Retirement made time available, and I came gradually to the idea to teach about what was my basic job. I thought also about other kinds of people who could be interested in such lessons: operators of refrigerators or liquefiers who, often by lack of time, did not get a proper introduction to their job when they started, young engineers who begin to work in cryogenics… and so on. Consequently, I have assembled a series of lessons about helium refrigeration. As the audiences have different levels of knowledge in the field of cryogenics, I looked for a way of teaching that is acceptable for all of them. The course is split into theory of heat exchangers, refrigeration cycles, technology and operation of main components, process control, and helium purity.

Stationary Refrigeration

EPA Pesticide Factsheets

Resources for HVACR contractors, technicians, equipment owners and other regulated industry to check rules and requirements for managing refrigerant emissions, information on how to become a certified technician, and compliance assistance documents.

Simulated performance of biomass gasification based combined power and refrigeration plant for community scale application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chattopadhyay, S., E-mail: suman.mech09@gmail.com; Mondal, P., E-mail: mondal.pradip87@gmail.com; Ghosh, S., E-mail: sudipghosh.becollege@gmail.com

Thermal performance analysis and sizing of a biomass gasification based combined power and refrigeration plant (CPR) is reported in this study. The plant is capable of producing 100 kWe of electrical output while simultaneously producing a refrigeration effect, varying from 28-68 ton of refrigeration (TR). The topping gas turbine cycle is an indirectly heated all-air cycle. A combustor heat exchanger duplex (CHX) unit burns producer gas and transfer heat to air. This arrangement avoids complex gas cleaning requirements for the biomass-derived producer gas. The exhaust air of the topping GT is utilized to run a bottoming ammonia absorption refrigeration (AAR)more » cycle via a heat recovery steam generator (HRSG), steam produced in the HRSG supplying heat to the generator of the refrigeration cycle. Effects of major operating parameters like topping cycle pressure ratio (r{sub p}) and turbine inlet temperature (TIT) on the energetic performance of the plant are studied. Energetic performance of the plant is evaluated via energy efficiency, required biomass consumption and fuel energy savings ratio (FESR). The FESR calculation method is significant for indicating the savings in fuel of a combined power and process heat plant instead of separate plants for power and process heat. The study reveals that, topping cycle attains maximum power efficiency of 30%in pressure ratio range of 8-10. Up to a certain value of pressure ratio the required air flow rate through the GT unit decreases with increase in pressure ratio and then increases with further increase in pressure ratio. The capacity of refrigeration of the AAR unit initially decreases up to a certain value of topping GT cycle pressure ratio and then increases with further increase in pressure ratio. The FESR is found to be maximized at a pressure ratio of 9 (when TIT=1100°C), the maximum value being 53%. The FESR is higher for higher TIT. The heat exchanger sizing is also influenced by the topping cycle pressure

Enclosure for thermoelectric refrigerator and method

NASA Technical Reports Server (NTRS)

Park, Brian V. (Inventor); McGrath, Ralph D. (Inventor)

1997-01-01

An enclosed structure is provided for use with a refrigerator having a door assembly. The enclosed structure preferably contains superinsulation materials and a plurality of matching drawers. The enclosed structure preferably includes corner joints which minimize thermal energy transfer between adjacent superinsulation panels. The refrigerator may include a cooling system having a thermoelectric device for maintaining the temperature within the refrigerator at selected values. If desired, a fluid cooling system and an active gasket may also be provided between the door assembly and the enclosed structure. The fluid cooling system preferably includes a second thermoelectric device to maintain the temperature of fluid flowing through the active gasket at a selected value. The drawers associated with the refrigerator may be used for gathering, processing, shipping and storing food or other perishable items.

Refrigeration system having standing wave compressor

DOEpatents

Lucas, Timothy S.

1992-01-01

A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

Low cost microminiature refrigerators for large unit volume applications

NASA Technical Reports Server (NTRS)

Duboc, R. M., Jr.

1983-01-01

Photolithographic techniques were employed to fabricate small Joule-Thomson refrigerators in laminated substrates. The gas passages of a J-T refrigerator are formed by etching channels as narrow as 50 microns and as shallow as 5 microns in glass plates which are laminated together. Circular refrigerators on the order of 1.5 centimeters in diameter and .75 millimeters thick were produced which cool down to cryogenic temperatures in a few seconds, using Argon or Nitrogen, with no vacuum or radiation insulation. Smaller refrigerators are developed for both faster cooldown and low refrigeration capacity applications. By using this technology, custom refrigerators can be designed to meet specific application requirements.

Air Conditioning with Magnetic Refrigeration : An Efficient, Green Compact Cooling System Using Magnetic Refrigeration

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-09-01

BEETIT Project: Astronautics is developing an air conditioning system that relies on magnetic fields. Typical air conditioners use vapor compression to cool air. Vapor compression uses a liquid refrigerant to circulate within the air conditioner, absorb the heat, and pump the heat out into the external environment. Astronautics’ design uses a novel property of certain materials, called “magnetocaloric materials”, to achieve the same result as liquid refrigerants. These magnetocaloric materials essentially heat up when placed within a magnetic field and cool down when removed, effectively pumping heat out from a cooler to warmer environment. In addition, magnetic refrigeration uses nomore » ozone-depleting gases and is safer to use than conventional air conditioners which are prone to leaks.« less

Sorption cryogenic refrigeration - Status and future

NASA Technical Reports Server (NTRS)

Jones, Jack A.

1988-01-01

The operation principles of sorption cryogenic refrigeration are discussed. Sorption refrigerators have virtually no wear-related moving parts, have negligible vibration, and offer extremely long life (at least ten years), making it possible to obtain efficient, long life and low vibration cooling to as low as 7 K for cryogenic sensors. The physisorption and chemisorption systems recommended for various cooling ranges down to 7 K are described in detail. For long-life cooling at 4-5 K temperatures, a hybrid chemisorption-mechanical refrigeration system is recommended.

Drop-in substitute for dichlorodifluoromethane refrigerant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goble, G.H.

1993-06-01

A method for producing refrigeration in a refrigeration system designed for a dichlorodifluoromethane refrigerant is described, comprising drop-in substituting for said dichlorodifluoromethane a ternary mixture of about 2 to 20 weight percent isobutane, about 21 to 51 weight percent 1-chloro-1,1-difluoroethane, and about 41 to 71 weight percent chlorodifluoromethane, with the weight percentages of said components being weight percentages of the overall mixture; condensing said ternary mixture; and thereafter evaporating said ternary mixture in the vicinity of a body to be cooled.

Improving Control in a Joule-Thomson Refrigerator

NASA Technical Reports Server (NTRS)

Borders, James; Pearson, David; Prina, Mauro

2005-01-01

A report discusses a modified design of a Joule-Thomson (JT) refrigerator under development to be incorporated into scientific instrumentation aboard a spacecraft. In most other JT refrigerators (including common household refrigerators), the temperature of the evaporator (the cold stage) is kept within a desired narrow range by turning a compressor on and off as needed. This mode of control is inadequate for the present refrigerator because a JT-refrigerator compressor performs poorly when the flow from its evaporator varies substantially, and this refrigerator is required to maintain adequate cooling power. The proposed design modifications include changes in the arrangement of heat exchangers, addition of a clamp that would afford a controlled heat leak from a warmer to a cooler stage to smooth out temperature fluctuations in the cooler stage, and incorporation of a proportional + integral + derivative (PID) control system that would regulate the heat leak to maintain the temperature of the evaporator within a desired narrow range while keeping the amount of liquid in the evaporator within a very narrow range in order to optimize the performance of the compressor. Novelty lies in combining the temperature- and cooling-power-regulating controls into a single control system.

Refrigerated Warehouse Demand Response Strategy Guide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scott, Doug; Castillo, Rafael; Larson, Kyle

This guide summarizes demand response measures that can be implemented in refrigerated warehouses. In an appendix, it also addresses related energy efficiency opportunities. Reducing overall grid demand during peak periods and energy consumption has benefits for facility operators, grid operators, utility companies, and society. State wide demand response potential for the refrigerated warehouse sector in California is estimated to be over 22.1 Megawatts. Two categories of demand response strategies are described in this guide: load shifting and load shedding. Load shifting can be accomplished via pre-cooling, capacity limiting, and battery charger load management. Load shedding can be achieved by lightingmore » reduction, demand defrost and defrost termination, infiltration reduction, and shutting down miscellaneous equipment. Estimation of the costs and benefits of demand response participation yields simple payback periods of 2-4 years. To improve demand response performance, it’s suggested to install air curtains and another form of infiltration barrier, such as a rollup door, for the passageways. Further modifications to increase efficiency of the refrigeration unit are also analyzed. A larger condenser can maintain the minimum saturated condensing temperature (SCT) for more hours of the day. Lowering the SCT reduces the compressor lift, which results in an overall increase in refrigeration system capacity and energy efficiency. Another way of saving energy in refrigerated warehouses is eliminating the use of under-floor resistance heaters. A more energy efficient alternative to resistance heaters is to utilize the heat that is being rejected from the condenser through a heat exchanger. These energy efficiency measures improve efficiency either by reducing the required electric energy input for the refrigeration system, by helping to curtail the refrigeration load on the system, or by reducing both the load and required energy input.« less

Birth after 12 hours of oocyte refrigeration.

PubMed

Coban, Onder; Hacifazlioglu, Oguzhan; Ciray, H Nadir; Ulug, Ulun; Tekin, H Ibrahim; Bahceci, Mustafa

2010-12-01

To assess cycle outcome after oocyte refrigeration. Case report. Private IVF center. One couple in a donor oocyte program. Intracytoplasmic sperm injection and blastocyst culture after refrigeration of oocytes for 12 hours. Birth. Fourteen two-pronuclei zygotes from 17 metaphase II refrigerated oocytes resulted in transfer of two blastocysts at day 5 and cryopreservation of six excess embryos at day 6. The patient delivered one healthy male baby after 38 weeks' gestation. The successful outcome of oocyte refrigeration indicates that this protocol could be useful in circumstances in which a delay in obtaining spermatozoa arises. Copyright © 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Experimental investigation of an alternating evaporator duty refrigerator/freezer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lavanis, M.; Haider, I.; Radermacher, R.

1998-12-31

A bistable solenoid valve has been used to build an alternating evaporator duty (AED) domestic refrigerator/freezer. This refrigerator has two vapor compression refrigeration loops that share a common compressor, condenser, and suction line heat exchanger. Each of the refrigeration loops has an expansion device and evaporator. One evaporator is located in the fresh food compartment and the other is located in the freezer compartment. The bistable solenoid valve directs the flow of the refrigerant through one loop at a time. Only one of the two compartments is cooled at any given time. With this configuration, the food compartment is cooledmore » at a higher evaporator temperature than the freezer. Due to this, the energy efficiency of the refrigerator is improved by 8.5% over a conventional domestic refrigerator/freezer. Also, this cycle allows for completely independent temperature control of the freezer and fresh food compartments. There may be a penalty because this cycle does not allow for both loops to be simultaneously optimized. Isobutane was the only refrigerant used in this investigation.« less

Generalized equation of state for refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Y.; Sonntag, R.E.; Borgnakke, C.

1995-08-01

A new four-parameter generalized equation of state with three reference fluids has been developed for predicting thermodynamic properties of the methane and ethane-series refrigerants. The four chosen characteristic parameters are critical temperature, critical pressure, acentric factor, and the polarity factor proposed in this work. The three selected reference fluids are argon, n-butane and 1,1-difluoroethane (R-152a). When the results of this work are compared with the refrigerant experimental data, they show significant improvement over Lee and Kesler (1975) and Wu and Stiel (1985). If the characteristic parameters of the refrigerants of interest are not available, an estimation method based on themore » group contribution method is given. The ideal vapor-compression refrigeration cycle was studied using the newly developed generalized equation of state to verify the accuracy of this work.« less

46 CFR 128.410 - Ship's service refrigeration systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Ship's service refrigeration systems. 128.410 Section 128.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS... service refrigeration systems. No self-contained unit either for air-conditioning or for refrigerated...

46 CFR 128.410 - Ship's service refrigeration systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Ship's service refrigeration systems. 128.410 Section 128.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS... service refrigeration systems. No self-contained unit either for air-conditioning or for refrigerated...

46 CFR 128.410 - Ship's service refrigeration systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Ship's service refrigeration systems. 128.410 Section 128.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS... service refrigeration systems. No self-contained unit either for air-conditioning or for refrigerated...

46 CFR 128.410 - Ship's service refrigeration systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Ship's service refrigeration systems. 128.410 Section 128.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS... service refrigeration systems. No self-contained unit either for air-conditioning or for refrigerated...

46 CFR 128.410 - Ship's service refrigeration systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Ship's service refrigeration systems. 128.410 Section 128.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS... service refrigeration systems. No self-contained unit either for air-conditioning or for refrigerated...

Method of reducing chlorofluorocarbon refrigerant emissons to the atmosphere

DOEpatents

DeVault, Robert C.; Fairchild, Phillip D.; Biermann, Wendell J.

1990-01-01

A method is disclosed for reducing chloroflurocarbon (CFC) refrigerant emissions during removal or transfer or refrigerants from a vapor compression cooling system or heat pump which comprises contacting the refrigerant with a suitable sorbent material. The sorbent material allows for the storage and retention or the chlorofluorocarbon in non-gaseous form so that it does not tend to escape to the atmosphere where it would cause harm by contributing to ozone depletion. In other aspects of the invention, contacting of CFC refrigerants with sorbent material allows for purification and recycling of used refrigerant, and a device containing stored sorbent material can be employed in the detection of refrigerant leakage in a cooling system or heat pump.

REDUCING REFRIGERANT EMISSIONS FROM SUPERMARKET SYSTEMS

EPA Science Inventory

Large refrigeration systems are found in several applications including supermarkets, cold storage warehouses, and industrial processes. The sizes of these systems are a contributing factor to their problems of high refrigerant leak rates because of the thousands of connections, ...

Quantum-Circuit Refrigerator

NASA Astrophysics Data System (ADS)

MöTtöNen, Mikko; Tan, Kuan Y.; Masuda, Shumpei; Partanen, Matti; Lake, Russell E.; Govenius, Joonas; Silveri, Matti; Grabert, Hermann

Quantum technology holds great potential in providing revolutionizing practical applications. However, fast and precise cooling of the functional quantum degrees of freedom on demand remains a major challenge in many solid-state implementations, such as superconducting circuits. We demonstrate direct cooling of a superconducting resonator mode using voltage-controllable quantum tunneling of electrons in a nanoscale refrigerator. In our first experiments on this type of a quantum-circuit refrigerator, we measure the drop in the mode temperature by electron thermometry at a resistor which is coupled to the resonator mode through ohmic losses. To eliminate unwanted dissipation, we remove the probe resistor and directly observe the power spectrum of the resonator output in agreement with the so-called P(E) theory. We also demonstrate in microwave reflection experiments that the internal quality factor of the resonator can be tuned by orders of magnitude. In the future, our refrigerator can be integrated with different quantum electric devices, potentially enhancing their performance. For example, it may prove useful in the initialization of superconducting quantum bits and in dissipation-assisted quantum annealing. We acknowledge European Research Council Grant SINGLEOUT (278117) and QUESS (681311) for funding.

Solar-Powered Refrigeration System

NASA Technical Reports Server (NTRS)

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2001-01-01

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure. and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Solar-Powered Refrigeration System

NASA Technical Reports Server (NTRS)

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2002-01-01

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Solar Powered Refrigeration System

NASA Technical Reports Server (NTRS)

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2002-01-01

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Claims in vapour device (e-cigarette) regulation: A Narrative Policy Framework analysis.

PubMed

O'Leary, Renée; Borland, Ron; Stockwell, Tim; MacDonald, Marjorie

2017-06-01

The electronic cigarette or e-cigarette (vapour device) is a consumer product undergoing rapid growth, and governments have been adopting regulations on the sale of the devices and their nicotine liquids. Competing claims about vapour devices have ignited a contentious debate in the public health community. What claims have been taken up in the state arena, and how have they possibly influenced regulatory outcomes? This study utilized Narrative Policy Framework to analyze the claims made about vapour devices in legislation recommendation reports from Queensland Australia, Canada, and the European Union, and the 2016 deeming rule legislation from the United States, and examined the claims and the regulatory outcomes in these jurisdictions. The vast majority of claims in the policy documents represented vapour devices as a threat: an unsafe product harming the health of vapour device users, a gateway product promoting youth tobacco uptake, and a quasi-tobacco product impeding tobacco control. The opportunity for vapour devices to promote cessation or reduce exposure to toxins was very rarely presented, and these positive claims were not discussed at all in two of the four documents studied. The dominant claims of vapour devices as a public health threat have supported regulations that have limited their potential as a harm reduction strategy. Future policy debates should evaluate the opportunities for vapour devices to decrease the health and social burdens of the tobacco epidemic. Copyright © 2017 Elsevier B.V. All rights reserved.

Component-wise exergy and energy analysis of vapor compression refrigeration system using mixture of R134a and LPG as refrigerant

NASA Astrophysics Data System (ADS)

Gill, Jatinder; Singh, Jagdev

2018-05-01

In this work, the experimental examination was carried out using a mixture of R134a and LPG refrigerant (consisting of R134a and LPG in a proportion of 28:72 by weight) as a replacement for R134a in a vapor compression refrigeration system. Exergy and energy tests were carried out at different evaporator and condenser temperatures with controlled environmental conditions. The results showed that the exergy destruction in the compressor, condenser, evaporator, and a capillary tube of the R134a / LPG refrigeration system was found lower by approximately 11.13-3.41%, 2.24-3.43%, 12.02-13.47% and 1.54-5.61% respectively. The compressor exhibits the highest level of destruction, accompanied by a condenser, an evaporator and a capillary tube in refrigeration systems. The refrigeration capacity, COP and power consumption of the compressor of the R134a /LPG refrigeration system were detected higher and lower compared to the R134a refrigeration system by about 7.04-11.41%, 15.1-17.82%, and 3.83-8.08% respectively. Also, the miscibility of R134a and LPG blend with mineral oil discovered good. The R134a and LPG refrigerant mixture proposed in this study perform superior to R134a from component-wise exergy and energy analyses under similar experimental conditions.

Correlation of refrigerant mass flow rate through adiabatic capillary tubes using mixture refrigerant carbondioxide and ethane for low temperature applications

NASA Astrophysics Data System (ADS)

Nasruddin, Syaka, Darwin R. B.; Alhamid, M. Idrus

2012-06-01

Various binary mixtures of carbon dioxide and hydrocarbons, especially propane or ethane, as alternative natural refrigerants to Chlorofluorocarbons (CFCs) or Hydro fluorocarbons (HFCs) are presented in this paper. Their environmental performance is friendly, with an ozone depletion potential (ODP) of zero and Global-warming potential (GWP) smaller than 20. The capillary tube performance for the alternative refrigerant HFC HCand mixed refrigerants have been widely studied. However, studies that discuss the performance of the capillary tube to a mixture of natural refrigerants, in particular a mixture of azeotrope carbon dioxide and ethane is still undeveloped. A method of empirical correlation to determine the mass flow rate and pipe length has an important role in the design of the capillary tube for industrial refrigeration. Based on the variables that effect the rate of mass flow of refrigerant in the capillary tube, the Buckingham Pi theorem formulated eight non-dimensional parameters to be developed into an empirical equations correlation. Furthermore, non-linear regression analysis used to determine the co-efficiency and exponent of this empirical correlation based on experimental verification of the results database.

Atrial and ventricular septal changes in ethanol vapour exposed chick embryos.

PubMed

Kamran, Kiran; Khan, Muhammad Yunus; Minhas, Liaqat Ali

2015-03-01

To study the effects of ethanol vapour exposure on development of atrial and ventricular septa of chick embryo. The experimental study was conducted at the College of Physicians and Surgeons, Islamabad, from 2006 to 2007. The experimental and control groups were further divided into three subgroups based on the day of sacrifice. The experimental group was exposed to ethanol vapours produced in a specially-designed vapour chamber and then compared with age-matched controls. There were 90 eggs in each of the two groups. The development of inter-ventricular septum completed at day 7 of development in chick embryo. Ethanol vapour exposure produced a small discontinuity at day 10 of development in a chick embryo which may be labelled as ventricular septal defect since ventricular development is completed by day 7. Interatrial septum formed till day 7 with small perforations which persisted till hatching. Ethanol vapour exposure may lead to ventricular septal defect.

Vapour phase techniques for deposition of CZTS thin films: A review

NASA Astrophysics Data System (ADS)

Kaur, Ramanpreet; Kumar, Sandeep; Singh, Sukhpal

2018-05-01

With the surge of thin film photovoltaic technologies in recent years, for cost reduction and increased production there is a need for earth abundant and non-toxic raw materials. Existing thin film solar cells comprising CuInS2 (CIS), CuInGaSe2 (CIGS) and CdTe contain elements that are rare in earth's crust and in case of CdTe toxic. Cu2ZnSnS4 (CZTS), having Kesterite structure, a direct band gap of 1.4 - 1.5 eV and an absorption coefficient of 104 cm-1 makes a promising candidate for absorber layer in thin film solar cells. So far many physical and chemical techniques have been employed for deposition of CZTS thin films. This review focuses on various vapour phase techniques used for fabrication of films, recent advances in these techniques and their future outlook.

Human skin absorption of Bis-2-(chloroethyl)sulphide (sulphur mustard) in vitro.

PubMed

Chilcott, R P; Jenner, J; Carrick, W; Hotchkiss, S A; Rice, P

2000-01-01

The purpose of this study was to measure the absorption and intra-epidermal fate of 35S-radiolabelled sulphur mustard (35SM) in human breast skin in vitro. Skin (full-thickness or heat-separated epidermis) was placed into static diffusion cells and was exposed to droplets of liquid 35SM or saturated 35SM vapour. Amounts of 35SM penetrating the skin were measured from which skin absorption rates were calculated. Unbound radiolabel was washed from the surface, extracted from the skin and analysed to determine the identity of the radiolabelled species in order to measure the extent of hydrolysis of sulphur mustard. Penetration rates of liquid 35SM measured in vitro (71-294 microg cm(-2) h(-1)) were in agreement with those measured previously in vivo using human volunteers (60-240 microg cm(-2) h(-1)). Rates of liquid 35SM skin absorption under occluded, infinite dose conditions were highest through heat-separated epidermal membranes (294+/-58 microg cm(-2) h(-1)) and lowest through full-thickness skin (71+/-14 microg cm(-2) h(-1)). Fluxes of saturated 35SM vapour (110+/-75 microg cm(-2) h(-1)) through heat-separated membranes were similar to those previously measured through human forearm skin in vivo (162 microg cm(-2) h(-1)). Although hydrolysis of 35SM did occur, both on the surface and within the skin, it accounted for only a small percentage of the total applied dose (<2.7+/-1.2%). The difference in total amount of liquid 35SM penetrated between occluded and unoccluded conditions in vitro (79+/-14%) was similar to that lost as vapour from unoccluded skin in vivo (80%). A substantial reservoir of 35SM (14-36% of the applied dose) was measured within heat-separated epidermal membranes for up to 24 h which may have significant implications for the management of personnel exposed to sulphur mustard.

Sensing response of copper phthalocyanine salt dispersed glass with organic vapours

NASA Astrophysics Data System (ADS)

Ridhi, R.; Sachdeva, Sheenam; Saini, G. S. S.; Tripathi, S. K.

2016-05-01

Copper Phthalocyanine and other Metal Phthalocyanines are very flexible and tuned easily to modify their structural, spectroscopic, optical and electrical properties by either functionalizing them with various substituent groups or by replacing or adding a ligand to the central metal atom in the phthalocyanine ring and accordingly can be made sensitive and selective to various organic species or gaseous vapours. In the present work, we have dispersed Copper Phthalocyanine Salt (CuPcS) in sol-gel glass form using chemical route sol-gel method and studied its sensing mechanism with organic vapours like methanol and benzene and found that current increases onto their exposure with vapours. A variation in the activation energies was also observed with exposure of vapours.

Neon turbo-Brayton cycle refrigerator for HTS power machines

NASA Astrophysics Data System (ADS)

Hirai, Hirokazu; Hirokawa, M.; Yoshida, Shigeru; Nara, N.; Ozaki, S.; Hayashi, H.; Okamoto, H.; Shiohara, Y.

2012-06-01

We developed a prototype turbo-Brayton refrigerator whose working fluid is neon gas. The refrigerator is designed for a HTS (High Temperature Superconducting) power transformer and its cooling power is more than 2 kW at 65 K. The refrigerator has a turboexpander and a turbo-compressor, which utilize magnetic bearings. These rotational machines have no rubbing parts and no oil-components. Those make a long maintenance interval of the refrigerator. The refrigerator is very compact because our newly developed turbo-compressor is volumetrically smaller than a displacement type compressor in same operating specification. Another feature of the refrigerator is a wide range operation capability for various heat-loads. Cooling power is controlled by the input-power of the turbo-compressor instead of the conventional method of using an electric heater. The rotational speed of the compressor motor is adjusted by an inverter. This system is expected to be more efficient. We show design details, specification and cooling test results of the new refrigerator in this paper.

46 CFR 98.25-35 - Refrigerated systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... temperature of the liquid below atmospheric, at least two complete refrigeration plants automatically... auxiliaries for proper operation. The capacity of each refrigeration compressor shall be sufficient to...

46 CFR 98.25-35 - Refrigerated systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... temperature of the liquid below atmospheric, at least two complete refrigeration plants automatically... auxiliaries for proper operation. The capacity of each refrigeration compressor shall be sufficient to...

46 CFR 98.25-35 - Refrigerated systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... temperature of the liquid below atmospheric, at least two complete refrigeration plants automatically... auxiliaries for proper operation. The capacity of each refrigeration compressor shall be sufficient to...

46 CFR 98.25-35 - Refrigerated systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... temperature of the liquid below atmospheric, at least two complete refrigeration plants automatically... auxiliaries for proper operation. The capacity of each refrigeration compressor shall be sufficient to...

46 CFR 98.25-35 - Refrigerated systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... temperature of the liquid below atmospheric, at least two complete refrigeration plants automatically... auxiliaries for proper operation. The capacity of each refrigeration compressor shall be sufficient to...

Evaluating alternative refrigerants for high ambient temperature environments

DOE PAGES

Abdelaziz, Omar; Shrestha, Som S.

2016-01-01

According to the Montreal Protocol, developing countries have started the phase out schedule of the ozone depleting substances, including HCFC refrigerants, in 2015 and expect them to reach 35% reduction in 2020. This commitment to the start the phase out of HCFC refrigerants, especially R-22, in developing countries is seen as an opportunity to introduce lower Global Warming Potential (GWP) refrigerants. Furthermore, this paper summarizes an investigation into the performance of lower GWP refrigerants in high ambient temperature environments, experienced in some of the developed countries, in mini-split air conditioning units.

The Thermodynamics of a Refrigeration System.

ERIC Educational Resources Information Center

Azevedo e Silva, J. F. M.

1991-01-01

An attempt to clarify the teaching of some of the concepts of thermodynamics through the observation of an experiment with an ordinary refrigeration system is presented. The cycle of operation in the refrigeration system and the individual processes in the cycle are described. (KR)

CO 2-fluxing collapses metal mobility in magmatic vapour

DOE PAGES

van Hinsberg, V. J.; Berlo, K.; Migdisov, A. A.; ...

2016-05-18

Magmatic systems host many types of ore deposits, including world-class deposits of copper and gold. Magmas are commonly an important source of metals and ore-forming fluids in these systems. In many magmatic-hydrothermal systems, low-density aqueous fluids, or vapours, are significant metal carriers. Such vapours are water-dominated shallowly, but fluxing of CO 2-rich vapour exsolved from deeper magma is now recognised as ubiquitous during open-system magma degassing. Furthermore, we show that such CO 2-fluxing leads to a sharp drop in element solubility, up to a factor of 10,000 for Cu, and thereby provides a highly efficient, but as yet unrecognised mechanismmore » for metal deposition.« less

Space shuttle orbiter mechanical refrigeration system

NASA Technical Reports Server (NTRS)

Williams, J. L.

1974-01-01

A radiator/condenser was designed which is efficient in both condensation (refrigeration) and liquid phase (radiator) operating modes, including switchover from the refrigeration mode to the radiator mode and vice versa. A method for predicting the pressure drop of a condensing two-phase flow in zero-gravity was developed along with a method for predicting the flow regime which would prevail along the condensation path. The hybrid refrigeration system was assembled with the two radiator/condenser panels installed in a space environment simulator. The system was tested under both atmospheric and vacuum conditions. Results of the tests are presented.

Refrigeration Compressors for the Altitude Wind Tunnel

NASA Image and Video Library

1944-09-21

These compressors inside the Refrigeration Building at the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory were used to generate cold temperatures in the Altitude Wind Tunnel (AWT) and Icing Research Tunnel. The AWT was a large facility that simulated actual flight conditions at high altitudes. The two primary aspects of altitude simulation are the reduction of the air pressure and the decrease of temperature. The Icing Research Tunnel was a smaller facility in which water droplets were added to the refrigerated air stream to simulate weather conditions that produced ice buildup on aircraft. The military pressured the NACA to complete the tunnels quickly so they could be of use during World War II. The NACA engineers struggled with the design of this refrigeration system, so Willis Carrier, whose Carrier Corporation had pioneered modern refrigeration, took on the project. The Carrier engineers devised the largest cooling system of its kind in the world. The system could lower the tunnels’ air temperature to –47⁰ F. The cooling system was powered by 14 Carrier and York compressors, seen in this photograph, which were housed in the Refrigeration Building between the two wind tunnels. The compressors converted the Freon 12 refrigerant into a liquid. The refrigerant was then pumped into zig-zag banks of cooling coils inside the tunnels’ return leg. The Freon absorbed heat from the airflow as it passed through the coils. The heat was transferred to the cooling water and sent to the cooling tower where it was dissipated into the atmosphere.

7 CFR 3300.37 - Testing of a mechanical refrigerating appliance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Testing of a mechanical refrigerating appliance. 3300... SPECIAL EQUIPMENT Procedures for Separate Testing of Mechanical Refrigerating Appliances § 3300.37 Testing of a mechanical refrigerating appliance. For separate testing of a mechanical refrigerating appliance...

Vaccine refrigeration: thinking outside of the box.

PubMed

McColloster, Patrick J; Martin-de-Nicolas, Andres

2014-01-01

This commentary reviews recent changes in Centers for Disease Control (CDC) vaccine storage guidelines that were developed in response to an investigative report by the Office of the Inspector General. The use of temperature data loggers with probes residing in glycol vials is advised along with storing vaccines in pharmaceutical refrigerators. These refrigerators provide good thermal distribution but can warm to 8 °C in less than one hour after the power is discontinued. Consequently, electric grid instability influences appropriate refrigerator selection and the need for power back-up. System Average Interruption Duration Index (SAIDI) values quantify this instability and can be used to formulate region-specific guidelines. A novel aftermarket refrigerator with a battery back-up power supply and microprocessor control system is also described.

Refrigeration of rainbow trout gametes and embryos.

PubMed

Babiak, Igor; Dabrowski, Konrad

2003-12-01

Prolonged access to early embryos composed of undifferentiated, totipotent blastomeres is desirable in situations when multiple collections of gametes are not possible. The objective of the present study is to examine whether the refrigeration of rainbow trout Oncorhynchus mykiss gametes and early embryos would be a suitable, reliable, and efficient tool for prolonging the availability of early developmental stages up to the advanced blastula stage. The study was conducted continuously during fall, winter, and spring spawning seasons. In all, more than 500 experimental variants were performed involving individual samples from 26 females and 33 males derived from three strains. These strains represented three possible circumstances. In optimal one, gametes from good quality donors were obtained soon after ovulation. In the two non-optimal sources, either donors were of poor genetic quality or gametes were collected from a distant location and transported as unfertilized gametes. A highly significant effect of variability of individual sample quality on efficiency of gamete and embryo refrigeration was revealed. The source of gametes significantly affected viability of refrigerated oocytes and embryos, but not spermatozoa. On average, oocytes from optimal source retained full fertilization viability for seven days of chilled storage, significantly longer than from non-optimal sources. Spermatozoa, regardless of storage method, retained full fertilization ability for the first week of storage. Refrigeration of embryos at 1.4+/-0.4 degrees C significantly slowed the development. Two- week-old embryos were still in blastula stage. Average survival rate of embryos refrigerated for 10 days and then transferred to regular incubation temperatures of 9-14 degrees C was 92% in optimal and 51 and 71% in non-optimal source variants. No effect of gamete and embryo refrigeration on the occurrence of developmental abnormalities was observed. Cumulative refrigeration of oocytes and

Optimal low symmetric dissipation Carnot engines and refrigerators

NASA Astrophysics Data System (ADS)

de Tomás, C.; Hernández, A. Calvo; Roco, J. M. M.

2012-01-01

A unified optimization criterion for Carnot engines and refrigerators is proposed. It consists of maximizing the product of the heat absorbed by the working system times the efficiency per unit time of the device, either the engine or the refrigerator. This criterion can be applied to both low symmetric dissipation Carnot engines and refrigerators. For engines the criterion coincides with the maximum power criterion and then the Curzon-Ahlborn efficiency ηCA=1-Tc/Th is recovered, where Th and Tc are the temperatures of the hot and cold reservoirs, respectively [Esposito, Kawai, Lindenberg, and Van den Broeck, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.105.150603 105, 150603 (2010)]. For refrigerators the criterion provides the counterpart of Curzon-Ahlborn efficiency for refrigerators ɛCA=[1/(1-(Tc/Th)]-1, first derived by Yan and Chen for the particular case of an endoreversible Carnot-type refrigerator with linear (Newtonian) finite heat transfer laws [Yan and Chen, J. Phys. D: Appl. Phys.JPAPBE0022-372710.1088/0022-3727/23/2/002 23, 136 (1990)].

Sensing response of copper phthalocyanine salt dispersed glass with organic vapours

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ridhi, R.; Sachdeva, Sheenam; Saini, G. S. S.

2016-05-06

Copper Phthalocyanine and other Metal Phthalocyanines are very flexible and tuned easily to modify their structural, spectroscopic, optical and electrical properties by either functionalizing them with various substituent groups or by replacing or adding a ligand to the central metal atom in the phthalocyanine ring and accordingly can be made sensitive and selective to various organic species or gaseous vapours. In the present work, we have dispersed Copper Phthalocyanine Salt (CuPcS) in sol-gel glass form using chemical route sol-gel method and studied its sensing mechanism with organic vapours like methanol and benzene and found that current increases onto their exposuremore » with vapours. A variation in the activation energies was also observed with exposure of vapours.« less

Heat pump employing optimal refrigerant compressor for low pressure ratio applications

DOEpatents

Ecker, Amir L.

1982-01-01

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler for circulating the fluid in heat exchange relationship with a refrigerant fluid; two refrigerant heat exchangers; one for effecting the heat exchange with the fluid and a second refrigerant-heat exchange fluid heat exchanger for effecting a low pressure ratio of compression of the refrigerant; a rotary compressor for compressing the refrigerant with low power consumption at the low pressure ratio; at least one throttling valve connecting at the inlet side of heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit serially connecting the above elements; refrigerant in the circuit; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant.

Vapour phase motion in cryogenic systems containing superheated and subcooled liquids

NASA Astrophysics Data System (ADS)

Kirichenko, Yu. A.; Chernyakov, P. S.; Seregin, V. E.

The development of vent pipelines, and venting storage tanks for cryogenic liquids requires the knowledge of the law of motion as well as regularities of vapour content variation in the liquid and heat dissipation by the vapour phase. This is a theoretical study of the effect of superheating (subcooling) of the liquid, relative acceleration and reduced pressure upon the size and velocity of noninteracting vapour bubbles, moving in the liquid, and upon their resistance and heat transfer coefficients.

Two stage sorption type cryogenic refrigerator including heat regeneration system

NASA Technical Reports Server (NTRS)

Jones, Jack A. (Inventor); Wen, Liang-Chi (Inventor); Bard, Steven (Inventor)

1989-01-01

A lower stage chemisorption refrigeration system physically and functionally coupled to an upper stage physical adsorption refrigeration system is disclosed. Waste heat generated by the lower stage cycle is regenerated to fuel the upper stage cycle thereby greatly improving the energy efficiency of a two-stage sorption refrigerator. The two stages are joined by disposing a first pressurization chamber providing a high pressure flow of a first refrigerant for the lower stage refrigeration cycle within a second pressurization chamber providing a high pressure flow of a second refrigerant for the upper stage refrigeration cycle. The first pressurization chamber is separated from the second pressurization chamber by a gas-gap thermal switch which at times is filled with a thermoconductive fluid to allow conduction of heat from the first pressurization chamber to the second pressurization chamber.

Two-statge sorption type cryogenic refrigerator including heat regeneration system

NASA Technical Reports Server (NTRS)

Jones, Jack A. (Inventor); Wen, Liang-Chi (Inventor); Bard, Steven (Inventor)

1989-01-01

A lower stage chemisorption refrigeration system physically and functionally coupled to an upper stage physical adsorption refrigeration system. Waste heat generated by the lower stage cycle is regenerated to fuel the upper stage cycle thereby greatly improving the energy efficiency of a two-stage sorption refrigerator. The two stages are joined by disposing a first pressurization chamber providing a high pressure flow of a first refrigerant for the lower stage refrigeration cycle within a second pressurization chamber providing a high pressure flow of a second refrigerant for the upper stage refrigeration cycle. The first pressurization chamber is separated from the second pressurization chamber by a gas-gap thermal switch which at times is filled with a thermoconductive fluid to allow conduction of heat from the first pressurization chamber to the second pressurization chamber.

Wheel-type magnetic refrigerator

DOEpatents

Barclay, J.A.

1983-10-11

The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load. 7 figs.

Wheel-type magnetic refrigerator

DOEpatents

Barclay, John A.

1983-01-01

The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load.

Wheel-type magnetic refrigerator

DOEpatents

Barclay, J.A.

1982-01-20

The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load.

21 CFR 1250.34 - Refrigeration equipment.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Refrigeration equipment. 1250.34 Section 1250.34 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment...

21 CFR 1250.34 - Refrigeration equipment.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Refrigeration equipment. 1250.34 Section 1250.34 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment...

21 CFR 1250.34 - Refrigeration equipment.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Refrigeration equipment. 1250.34 Section 1250.34 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment...

21 CFR 1250.34 - Refrigeration equipment.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Refrigeration equipment. 1250.34 Section 1250.34 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment...

21 CFR 1250.34 - Refrigeration equipment.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Refrigeration equipment. 1250.34 Section 1250.34 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment...

7 CFR 58.154 - Refrigerated storage.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Refrigerated storage. 58.154 Section 58.154... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Storage of Finished Product § 58.154 Refrigerated storage. Finished product in containers subject to such conditions that will...

7 CFR 58.154 - Refrigerated storage.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Refrigerated storage. 58.154 Section 58.154... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Storage of Finished Product § 58.154 Refrigerated storage. Finished product in containers subject to such conditions that will...

7 CFR 58.154 - Refrigerated storage.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Refrigerated storage. 58.154 Section 58.154... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Storage of Finished Product § 58.154 Refrigerated storage. Finished product in containers subject to such conditions that will...

7 CFR 58.154 - Refrigerated storage.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Refrigerated storage. 58.154 Section 58.154... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Storage of Finished Product § 58.154 Refrigerated storage. Finished product in containers subject to such conditions that will...

7 CFR 58.154 - Refrigerated storage.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Refrigerated storage. 58.154 Section 58.154... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Storage of Finished Product § 58.154 Refrigerated storage. Finished product in containers subject to such conditions that will...

Compatibility of refrigerants and lubricants with elastomers. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamed, G.R.; Seiple, R.H.; Taikum, Orawan

1994-01-01

The information contained in this report is designed to assist the air-conditioning and refrigeration industry in the selection of suitable elastomeric gasket and seal materials that will prove useful in various refrigerant and refrigeration lubricant environments. In part I of the program the swell behavior in the test fluids has been determined using weight and in situ diameter measurements for the refrigerants and weight, diameter and thickness measurements for the lubricants. Weight and diameter measurements are repeated after 2 and 24 hours for samples removed fro the refrigerant test fluids and 24 hours after removal from the lubricants. Part IImore » of the testing program includes the evaluation of tensile strength, hardness, weight, and dimensional changes after immersion aging in refrigerant/lubricant mixtures of selected elastomer formulations at elevated temperature and pressure.« less

A water vapour monitor at Paranal Observatory

NASA Astrophysics Data System (ADS)

Kerber, Florian; Rose, Thomas; Chacón, Arlette; Cuevas, Omar; Czekala, Harald; Hanuschik, Reinhard; Momany, Yazan; Navarrete, Julio; Querel, Richard R.; Smette, Alain; van den Ancker, Mario E.; Cure, Michel; Naylor, David A.

2012-09-01

We present the performance characteristics of a water vapour monitor that has been permanently deployed at ESO's Paranal observatory as a part of the VISIR upgrade project. After a careful analysis of the requirements and an open call for tender, the Low Humidity and Temperature Profiling microwave radiometer (LHATPRO), manufactured by Radiometer Physics GmbH (RPG), has been selected. The unit measures several channels across the strong water vapour emission line at 183 GHz, necessary for resolving the low levels of precipitable water vapour (PWV) that are prevalent on Paranal (median ~2.5 mm). The unit comprises the above humidity profiler (183-191 GHz), a temperature profiler (51-58 GHz), and an infrared radiometer (~10 μm) for cloud detection. The instrument has been commissioned during a 2.5 week period in Oct/Nov 2011, by comparing its measurements of PWV and atmospheric profiles with the ones obtained by 22 radiosonde balloons. In parallel an IR radiometer (Univ. Lethbridge) has been operated, and various observations with ESO facility spectrographs have been taken. The RPG radiometer has been validated across the range 0.5 - 9 mm demonstrating an accuracy of better than 0.1 mm. The saturation limit of the radiometer is about 20 mm. Currently, the radiometer is being integrated into the Paranal infrastructure to serve as a high time-resolution monitor in support of VLT science operations. The water vapour radiometer's ability to provide high precision, high time resolution information on this important aspect of the atmosphere will be most useful for conducting IR observations with the VLT under optimal conditions.

Stratospheric water vapour in the vicinity of the Arctic polar vortex

NASA Astrophysics Data System (ADS)

Maturilli, M.; Fierli, F.; Yushkov, V.; Lukyanov, A.; Khaykin, S.; Hauchecorne, A.

2006-07-01

The stratospheric water vapour mixing ratio inside, outside, and at the edge of the polar vortex has been accurately measured by the FLASH-B Lyman-Alpha hygrometer during the LAUTLOS campaign in Sodankylä, Finland, in January and February 2004. The retrieved H2O profiles reveal a detailed view on the Arctic lower stratospheric water vapour distribution, and provide a valuable dataset for the validation of model and satellite data. Analysing the measurements with the semi-lagrangian advection model MIMOSA, water vapour profiles typical for the polar vortex' interior and exterior have been identified, and laminae in the observed profiles have been correlated to filamentary structures in the potential vorticity field. Applying the validated MIMOSA transport scheme to specific humidity fields from operational ECMWF analyses, large discrepancies from the observed profiles arise. Although MIMOSA is able to reproduce weak water vapour filaments and improves the shape of the profiles compared to operational ECMWF analyses, both models reveal a dry bias of about 1 ppmv in the lower stratosphere above 400 K, accounting for a relative difference from the measurements in the order of 20%. The large dry bias in the analysis representation of stratospheric water vapour in the Arctic implies the need for future regular measurements of water vapour in the polar stratosphere to allow the validation and improvement of climate models.

Solar Refrigerator/Freezers For Vaccines

NASA Technical Reports Server (NTRS)

Ratajczak, Anthony F.

1988-01-01

Report presents results of field tests of solar-cell-powered refrigerator/freezers for vaccines. Covers following topics: explanation of project; descriptions of refrigerator/freezer systems; account of installation experiences; performance data for 22 systems for which field-test data reported; summary of operational reliability; comments of users of some systems tested; and recommendations for design and future use. Photovoltaic systems store vaccines in remote regions where powerlines unavailable.

Evaluation of Alternative Refrigerants for Mini-Split Air Conditioners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelaziz, Omar; Shrestha, Som S

The phase-out of hydrochlorofluorocarbons (HCFC) refrigerants in developing countries is currently underway according to the Montreal Protocol. R-22 is one of the most commonly used HCFCs in the developing nations. It is extremely well suited for air conditioning and refrigeration (AC&R) in high ambient temperature environments. Non-Article 5 countries have already gone through the phase-out of HCFCs and settled on using R-410A as the refrigerant of choice for AC applications. Previous studies have shown that R-410A results in significant capacity and performance degradation at higher ambient temperature conditions. As such, there is a growing concern on finding alternative refrigerants tomore » R-22 that would have zero ODP, lower GWP, and at the same time maintain acceptable performance at higher ambient temperatures. Furthermore, the developed world s transition through higher global warming potential (GWP) refrigerants like HFC and HFC blends resulted in significant direct CO2 equivalent emissions. It is imperative to develop a bridge for developing nations to avoid the transition from HCFC to HFC and then from HFC to alternative lower GWP refrigerants. This paper summarizes data from an experimental campaign on alternative refrigerant evaluation for R-22 and R-410A substitutes for mini-split air conditioners designed for high ambient environments. The experimental evaluation was performed according to ANSI/ASHRAE Standard 37 and the performance was rated at test conditions specified by ANSI/AHRI 210-240 and ISO 5151. Additional tests were conducted at outdoor ambient temperatures of 52 C (125.6 F) and 55 C (131 F) to evaluate their performance at high ambient conditions. Alternative refrigerants, some of which are proprietary, included R-444B, DR-3, N-20b, ARM-20b, R-290, and DR-93 as alternatives to R-22 and R-32, DR-55, L41-2, ARM-71A, and HPR-2A as alternatives to R-410A. The units performances were first verified using the baseline refrigerant and then

Shuttle Kit Freezer Refrigeration Unit Conceptual Design

NASA Technical Reports Server (NTRS)

Copeland, R. J.

1975-01-01

The refrigerated food/medical sample storage compartment as a kit to the space shuttle orbiter is examined. To maintain the -10 F in the freezer kit, an active refrigeration unit is required, and an air cooled Stirling Cycle refrigerator was selected. The freezer kit contains two subsystems, the refrigeration unit, and the storage volume. The freezer must provide two basic capabilities in one unit. One requirement is to store 215 lbs of food which is consumed in a 30-day period by 7 people. The other requirement is to store 128.3 lbs of medical samples consisting of both urine and feces. The unit can be mounted on the lower deck of the shuttle cabin, and will occupy four standard payload module compartments on the forward bulkhead. The freezer contains four storage compartments.

Improving NIS Tunnel Junction Refrigerators: Modeling, Materials, and Traps

NASA Astrophysics Data System (ADS)

O'Neil, Galen Cascade

This thesis presents a systematic study of electron cooling with Normal-metal/insulator/superconductor (NIS) tunnel junctions. NIS refrigerators have an exciting potential to simplify 100 mK and 10 mK cryogenics. Rather than using an expensive dilution refrigerator, researchers will be able to use much simpler cryogenics to reach 300 mK and supplement them with mass fabricated thin-film NIS refrigerators to reach 100 mK and below. The mechanism enabling NIS refrigeration is energy selective tunneling. Due to the gap in the superconducting density of states, only hot electrons tunnel from the normal-metal. Power is removed from the normal-metal, that same power and the larger IV power are both deposited in the superconductor. NIS refrigerators often cool less than theory predicts because of the power deposited in the superconductor returns to the normal-metal. When the superconductor temperature is raised, or athermal phonons due to quasiparticle recombination are absorbed in the normal-metal, refrigerator performance will be reduced. I studied the quasiparticle excitations in superconductors to develop the most complete thermal model of NIS refrigerators to date. I introduced overlayer quasiparticle traps, a new method for heatsinking the superconductor. I present measurements on NIS refrigerators with and without quasiparticle traps, to determine their effectiveness. This includes an NIS refrigerator that cools from 300 mK to 115 mK or lower, a large improvement over previous designs. I also looked into reducing the power deposited in the superconductor, by choosing the transition temperature of the superconductor based upon the NIS refrigerator launch temperature. I performed a detailed study of the density of states of superconducting AlMn alloys, demonstrating that Mn impurities behave non-magnetically in Al due to resonant scattering. The density of states remains BCS-like, but my measurements show that the deviations from a BCS density of states harm cooling

Mixed Refrigerants for a Glass Capillary Micro Cryogenic Cooler

DTIC Science & Technology

2010-08-01

refrigerant has the largest ðDhTÞmin 1.35 kJ/mol. To deliver 15 mW of gross refrigeration power, JT cryocoolers using mixed refrigerants only require 1.6...higher than 75 K. Pressure drop in heat exchangers can cause refrigeration loss in cryocooler systems. The minimum enthalpy difference and hence...micro- cryocoolers . They solved it by making the returning flow laminar through re-design- ing micro channels. Fig. 4 shows the relationship between the

Fault detection and diagnosis for refrigerator from compressor sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keres, Stephen L.; Gomes, Alberto Regio; Litch, Andrew D.

A refrigerator, a sealed refrigerant system, and method are provided where the refrigerator includes at least a refrigerated compartment and a sealed refrigerant system including an evaporator, a compressor, a condenser, a controller, an evaporator fan, and a condenser fan. The method includes monitoring a frequency of the compressor, and identifying a fault condition in the at least one component of the refrigerant sealed system in response to the compressor frequency. The method may further comprise calculating a compressor frequency rate based upon the rate of change of the compressor frequency, wherein a fault in the condenser fan is identifiedmore » if the compressor frequency rate is positive and exceeds a condenser fan fault threshold rate, and wherein a fault in the evaporator fan is identified if the compressor frequency rate is negative and exceeds an evaporator fan fault threshold rate.« less

Time-Temperature Profiling of United Kingdom Consumers' Domestic Refrigerators.

PubMed

Evans, Ellen W; Redmond, Elizabeth C

2016-12-01

Increased consumer demand for convenience and ready-to-eat food, along with changes to consumer food purchase and storage practices, have resulted in an increased reliance on refrigeration to maximize food safety. Previous research suggests that many domestic refrigerators operate at temperatures exceeding recommendations; however, the results of several studies were determined by means of one temperature data point, which, given temperature fluctuation, may not be a true indicator of actual continual operating temperatures. Data detailing actual operating temperatures and the effects of consumer practices on temperatures are limited. This study has collated the time-temperature profiles of domestic refrigerators in consumer kitchens (n = 43) over 6.5 days with concurrent self-reported refrigerator usage. Overall, the findings established a significant difference (P < 0.05) between one-off temperature (the recording of one temperature data point) and mean operating temperature. No refrigerator operated at ≤5.0°C for the entire duration of the study. Mean temperatures exceeding 5.0°C were recorded in the majority (91%) of refrigerators. No significant associations or differences were determined for temperature profiles and demographics, including household size, or refrigerator characteristics (age, type, loading, and location). A positive correlation (P < 0.05) between room temperature and refrigerator temperature was determined. Reported door opening frequency correlated with temperature fluctuation (P < 0.05). Thermometer usage was determined to be infrequent. Cumulatively, research findings have established that the majority of domestic refrigerators in consumer homes operate at potentially unsafe temperatures and that this is influenced by consumer usage. The findings from this study may be utilized to inform the development of shelf-life testing based on realistic domestic storage conditions. Furthermore, the data can inform the development of future

An experimental study for a miniature Stirling refrigerator

NASA Technical Reports Server (NTRS)

Li, S.; Chen, G.; Huang, Z.; Zhang, F.; Cui, C.; Li, J.

1985-01-01

Experimental results of a miniature two-stage Stirling cryocooler are introduced. The influence of filling gas pressure and refrigeration temperature on the refrigerating capacity along with the relationship between parameters was measured. The valley pressure corresponding to the lowest refrigeration temperature and the cooldown time versus operating pressure are discussed. The coefficient of performance and thermodynamic efficiency of the cryocooler are calculated based on experimental data.

Defrost Temperature Termination in Supermarket Refrigeration Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, Brian A; Sharma, Vishaldeep

2011-11-01

The objective of this project was to determine the potential energy savings associated with implementing demand defrost strategies to defrost supermarket refrigerated display case evaporators, as compared to the widely accepted current practice of controlling display case defrost cycles with a preset timer. The defrost heater energy use of several representative display case types was evaluated. In addition, demand defrost strategies for refrigerated display cases as well as those used in residential refrigerator/freezers were evaluated. Furthermore, it is anticipated that future work will include identifying a preferred defrost strategy, with input from Retail Energy Alliance members. Based on this strategy,more » a demand defrost system will be designed which is suitable for supermarket refrigerated display cases. Limited field testing of the preferred defrost strategy will be performed in a supermarket environment.« less

Helium refrigeration systems for super-conducting accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganni, V.

Many of the present day accelerators are based on superconducting technology which requires 4.5-K or 2-K helium refrigeration systems. These systems utilize superconducting radio frequency (SRF) cavities and/or superconducting magnets which are packaged into vacuum vessels known as cryo-modules (CM’s). Many of the present day accelerators are optimized to operate primarily at around 2-K, requiring specialized helium refrigeration systems which are cost intensive to produce and to operate. Some of the cryogenic refrigeration system design considerations for these challenging applications are discussed.

Floating Loop System For Cooling Integrated Motors And Inverters Using Hot Liquid Refrigerant

DOEpatents

Hsu, John S [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Coomer, Chester [Knoxville, TN; Marlino, Laura D [Oak Ridge, TN

2006-02-07

A floating loop vehicle component cooling and air-conditioning system having at least one compressor for compressing cool vapor refrigerant into hot vapor refrigerant; at least one condenser for condensing the hot vapor refrigerant into hot liquid refrigerant by exchanging heat with outdoor air; at least one floating loop component cooling device for evaporating the hot liquid refrigerant into hot vapor refrigerant; at least one expansion device for expanding the hot liquid refrigerant into cool liquid refrigerant; at least one air conditioning evaporator for evaporating the cool liquid refrigerant into cool vapor refrigerant by exchanging heat with indoor air; and piping for interconnecting components of the cooling and air conditioning system.

The dynamic effects of metal vapour in gas metal arc welding

NASA Astrophysics Data System (ADS)

Haidar, Jawad

2010-04-01

Numerical simulations for the dynamic effects of metal vapour in gas metal arc welding (GMAW) suggest that vapour from the welding droplet at the tip of the welding wire has a significant influence on the plasma properties. It is found that for the evaporation rates calculated for arcs in pure argon, the dynamic effects of metal vapour markedly cool down the plasma in the central region of the arc, leading to the formation of a low temperature zone centred on the arc axis, in agreement with experimental measurements in the literature. Radiation effects, omitted in this paper, may produce further cooling of the plasma gas. The results highlight major deficiencies in the common approach to modelling the GMAW process and suggest that accurate description of GMAW must include the influence of metal vapour on the plasma.

Assessment of Environmentally Friendly Refrigerants for Window Air Conditioners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep; Shen, Bo

This paper presents technical assessment of environmentally friendly refrigerants for window air conditioners that currently use refrigerant R410A for residential and commercial applications. The alternative refrigerants that are studied for its replacement include R32, R600a, R290, R1234yf, R1234ze and a mixture of R32 (90% molar concentration) and R125 (10% molar concentration). Baseline experiments were performed on a window unit charged with R410A. The ORNL Heat Pump Design Model was calibrated with the baseline data and was used to assess the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and theirmore » suitability for window air conditioners.« less

EVALUATION OF REFRIGERANT FROM MOBILE AIR CONDITIONERS

EPA Science Inventory

The report gives results of a project to provide a scientific basis for choosing a reasonable standard of purity for recycled chlorofluorocarbon (CFC) refrigerant in operating automobile air conditioners. The quality of refrigerant from air conditioners in automobiles of differen...

GPS tomographic experiment on water vapour dynamics in the troposphere over Lisbon

NASA Astrophysics Data System (ADS)

Benevides, Pedro; Catalao, Joao; Miranda, Pedro

2015-04-01

Quantification of the water vapour variability on the atmosphere remains a difficult task, affecting the weather prediction. Coarse water vapour resolution measurements in space and time affect the numerical weather prediction solution models causing artifacts in the prediction of severe weather phenomena. The GNSS atmospheric processing has been developed in the past years providing integrated water vapour estimates comparable with the meteorological sensor measurements, with studies registering 1 to 2 kg/m2 bias, but lack a vertical determination of the atmospheric processes. The GNSS tomography in the troposphere is one of the most promising techniques for sensing the three-dimensional water vapour state of the atmosphere. The determination of the integrated water vapour profile by means of the widely accepted GNSS meteorology techniques, allows the reconstruction of several slant path delay rays in the satellite line of view, providing an opportunity to sense the troposphere at tree-dimensions plus time. The tomographic system can estimate an image solution of the water vapour but impositions have to be introduced to the system of equations inversion because of the non-optimal GNSS observation geometry. Application of this technique on atmospheric processes like large convective precipitation or mesoscale water vapour circulation have been able to describe its local dynamic vertical variation. A 3D tomographic experiment was developed over an area of 60x60 km2 around Lisbon (Portugal). The GNSS network available composed by 9 receivers was used for an experiment of densification of the permanent network using 8 temporarily installed GPS receivers (totalling 17 stations). This study was performed during several weeks in July 2013, where a radiosonde campaign was also held in order to validate the tomographic inversion solution. 2D integrated water vapour maps directly obtained from the GNSS processing were also evaluated and local coastal breeze circulation

Vapour breakthrough behaviour of carbon tetrachloride - A simulant for chemical warfare agent on ASZMT carbon: A comparative study with whetlerite carbon

NASA Astrophysics Data System (ADS)

Srivastava, Avanish Kumar; Shah, Dilip K.; Mahato, T. H.; Roy, A.; Yadav, S. S.; Srivas, S. K.; Singh, Beer

2013-06-01

ASZMT and whetlerite carbon was prepared by impregnation of active carbon with ammonical salts of Cu (II), Ag (I), Zn (II), Mo (VI), TEDA and Cu (II), Ag (I), Cr (VI), NaOH, C5H5N respectively using incipient wetness technique. Thereafter, impregnated carbon systems were characterized using scanning electron microscopy, energy dispersive X-ray, atomic absorption spectroscopy, thermogravimetry and surface characterization techniques. Impregnated carbon systems were evaluated under dynamic conditions against carbon tetrachloride (CCl4) vapour that was used as a simulant for the persistent chemical warfare agents for testing breakthrough times of filter cartridges and canisters of gas masks in the national approval test of respirators. The protective potential of ASZMT carbon was compared with the whetlerite carbon which is presently used in NBC filtration system. The effect of CCl4 concentration, test flow rate, temperature and relative humidity on the breakthrough behaviour of the impregnated carbon systems has also been studied. The study clearly indicated that the whetlerite carbon possessed breakthrough time greater than ASZMT carbon. However, ASZMT carbon provided adequate protection against CCl4 vapours and can be used as an alternative to whetlerite carbon that contain Cr(VI), which is reported to be carcinogenic and having lesser shelf life. The study indicated the breakthrough time of impregnated carbon systems were found to decrease with the increase of the CCl4 concentration and flow rate. The variation in temperature and relative humidity did not significantly affect the breakthrough behaviour of impregnated carbon systems at high vapour concentration of CCl4 whereasbreak through time of impregnated carbon systems reduced by an increase of relative humidity at low CCl4 vapour concentration.

Condensation of nano-refrigerant inside a horizontal tube

NASA Astrophysics Data System (ADS)

Darzi, Milad; Sadoughi, M. K.; Sheikholeslami, M.

2018-05-01

In this paper, condensing pressure drop of refrigerant-based nanofluid inside a tube is studied. Isobutene was selected as the base fluid while CuO nanoparticles were utilized to prepare nano-refrigerant. However, for the feasibility of nanoparticle dispersion into the refrigerant, Polyester oil (POE) was utilized as lubricant oil and added to the pure refrigerant by 1% mass fraction. Various values of mass flux, vapor quality, concentration of nanoparticle are investigated. Results indicate that adding nanoparticles leads to enhance frictional pressure drop. Nanoparticles caused larger pressure drop penalty at relatively lower vapor qualities which may be attributed to the existing condensation flow pattern such that annular flow is less influenced by nanoparticles compared to intermittent flow regime.

Measurements of the levels of organic solvent vapours by personal air samplers and the levels of urinary metabolites of workers. Part 2. Toluene vapour in a shipbuilding yard (author's transl).

PubMed

Kira, S

1977-05-01

Personal air samplers were applied to shipyard's painters putting on gas masks during the spraying work, and the levels of toluene vapour surrounding the workers were measured. On the other hand, levels of urinary hippuric acid (metabolites of toluene) of the workers were measured, and the levels of toluene vapour inhaled were calculated from the levels of urinary hippuric acid. Then the actual removing-efficiencies of toluene vapours by the use of gas masks were estimated from these two levels (i.e., toluene vapours exposed and inhaled). The values of removing-efficiencies were found to be 65.9-98.1%. The concentrations of hippuric and methylhippuric acids in the urine of workers exposed to toluene and xylene for 3 hours, collected just after the exposure, are valuable indices of these organic solvent vapours inhaled. A minute amount of urinary methylhippuric acid can be determined by means of gas chromatography.

Supermarket refrigeration assessment for the Commonwealth Electric Company

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsaros, T.L.; Walker, D.H.

The Commonwealth Electric Company (COM/Electric) has initiated an incentive program to promote electric energy conservation within its service territory. The Electric Power Research Institute (EPRI) has assisted COM/Electric in assessing the impact on the utility and its customers of implementing energy efficient supermarket refrigeration in retrofit applications. The primary task of this assessment was to contact the supermarket chains and refrigeration contractors and suppliers in the COM/Electric service territory to determine the type of refrigeration employed and standard or novel retrofit equipment implemented in supermarkets. With this information, estimates were made of the potential energy savings that COM/Electric and themore » supermarkets could realize if supermarkets were retrofitted with energy efficient refrigeration equipment. It was determined that the refrigerated display case features offering the greatest potential for savings through retrofit installations include doors for medium temperature multideck cases, high-efficiency fan motors, anti-sweat heater controls, and vinyl strip curtains for walk-in coolers. The retrofit components associated with the compressor machine room that offer the greatest potential for savings include the use of low heat pressure control, hot gas defrost, and external liquid-suction heat exchangers and remote evaporative subcoolers for low temperature refrigeration. 6 refs., 14 figs., 26 tabs.« less

Advances in refrigeration and heat transfer engineering

DOE PAGES

Bansal, Pradeep; Cremaschi, Prof. Lorenzo

2015-05-13

This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO 2 may perhaps have beenmore » the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).« less

Advances in refrigeration and heat transfer engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep; Cremaschi, Prof. Lorenzo

This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO 2 may perhaps have beenmore » the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).« less

ARTI Refrigerant Database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

1992-11-09

The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air- conditioning and refrigeration equipment. The database identifies sources of specific information on R-32, R-123, R-124, R-125, R-134, R-134a, R-141b, R-142b, R-143a, R-152a, R-245ca, R-290 (propane), R- 717 (ammonia), ethers, and others as well as azeotropic and zeotropic and zeotropic blends of these fluids. It addresses lubricants including alkylbenzene, polyalkylene glycol, ester, and other synthetics as well as mineral oils. It also references documents on compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerantmore » circuits. A computerized version is available that includes retrieval software.« less

Vapour sensitivity of an ALD hierarchical photonic structure inspired by Morpho.

PubMed

Poncelet, Olivier; Tallier, Guillaume; Mouchet, Sébastien R; Crahay, André; Rasson, Jonathan; Kotipalli, Ratan; Deparis, Olivier; Francis, Laurent A

2016-05-09

The unique architecture of iridescent Morpho butterfly scales is known to exhibit different optical responses to various vapours. However, the mechanism behind this phenomenon is not fully quantitatively understood. This work reports on process developments in the micro-fabrication of a Morpho-inspired photonic structure in atomic layer deposited (ALD) materials in order to investigate the vapour optical sensitivity of such artificial nanostructures. By developing recipes for dry and wet etching of ALD oxides, we micro-fabricated two structures: one combining Al2O3 and TiO2, and the other combining Al2O3 and HfO2. For the first time, we report the optical response of such ALD Morpho-like structures measured under a controlled flow of either ethanol or isopropyl alcohol (IPA) vapour. In spite of the small magnitude of the effect, the results show a selective vapour response (depending on the materials used).

Energy and cost analysis of residential refrigerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoskins, R.A.; Hirst, E.

1977-01-01

A detailed computer model is developed to calculate energy flows and electricity use for residential refrigerators. Model equations are derived from applications of the first law of thermodynamics, analysis of manufacturers' literature, and related studies. The model is used to evaluate the energy (and associated initial cost) impacts of alternative designs to reduce refrigerator energy use. Model results show that 56 percent of the total heat gain in a typical 0.45 m/sup 3/ (16 ft/sup 3/) top-freezer refrigerator is due to conduction through cabinet walls and doors. The remaining 44 percent is from door openings, heaters, fans, food, gasket areamore » infiltration, and miscellaneous heat sources. Operation of the compressor to remove this heat and maintain the refrigerated spaces at constant temperatures accounts for 70 percent of the unit's electricity use. The remainder is for operation of heaters and fans. Several energy-saving design changes are examined using the energy model. These changes are: increased insulation thickness, improved insulation conductivity, removal of fan from cooled area, use of anti-sweat heater switch, improved compressor efficiency, increased condenser and evaporator surface areas, and elimination of the frost-free feature. Application of all these changes would reduce refrigerator electricity use 71 percent and increase initial cost 5 percent. Implementing all these changes except for elimination of the frost-free feature would reduce electricity use 52 percent and increase initial cost 19 percent. These results show that there are large opportunities for reducing refrigerator electricity use with only slight initial cost increases.« less

Cryogen-free dilution refrigerators

NASA Astrophysics Data System (ADS)

Uhlig, K.

2012-12-01

We review briefly our first cryogen-free dilution refrigerator (CF-DR) which was precooled by a GM cryocooler. We then show how today's dry DRs with pulse tube precooling have developed. A few examples of commercial DRs are explained and noteworthy features pointed out. Thereby we describe the general advantages of cryogen-free DRs, but also show where improvements are still desirable. At present, our dry DR has a base temperature of 10 mK and a cooling capacity of 700 μW at a mixing chamber temperature of 100 mK. In our cryostat, in most recent work, an additional refrigeration loop was added to the dilution circuit. This 4He circuit has a lowest temperature of about 1 K and a refrigeration capacity of up to 100 mW at temperatures slightly above 1 K; the dilution circuit and the 4He circuit can be run separately or together. The purpose of this additional loop is to increase the cooling capacity for experiments where the cooling power of the still of the DR is not sufficient to cool cold amplifiers and cables, e.g. in studies on superconducting quantum circuits or astrophysical applications.

DESIGN AND OPTIMIZATION OF A REFRIGERATION SYSTEM

EPA Science Inventory

The paper discusses the design and optimization of a refrigeration system, using a mathematical model of a refrigeration system modified to allow its use with the optimization program. he model was developed using only algebraic equations so that it could be used with the optimiz...

Commercial Refrigeration Technology. Florida Vocational Program Guide.

ERIC Educational Resources Information Center

University of South Florida, Tampa. Dept. of Adult and Vocational Education.

The program guide for commercial refrigeration technology courses in Florida identifies primary considerations for the organization, operation, and evaluation of a vocational education program. Following an occupational description for the job title for refrigeration mechanic, and its Dictionary of Occupational Titles code, are six sections…

Vertical structure of stratospheric water vapour trends derived from merged satellite data

PubMed Central

Hegglin, M. I.; Plummer, D. A.; Shepherd, T. G.; Scinocca, J. F.; Anderson, J.; Froidevaux, L.; Funke, B.; Hurst, D.; Rozanov, A.; Urban, J.; von Clarmann, T.; Walker, K. A.; Wang, H. J.; Tegtmeier, S.; Weigel, K.

2017-01-01

Stratospheric water vapour is a powerful greenhouse gas. The longest available record from balloon observations over Boulder, Colorado, USA shows increases in stratospheric water vapour concentrations that cannot be fully explained by observed changes in the main drivers, tropical tropopause temperatures and methane. Satellite observations could help resolve the issue, but constructing a reliable long-term data record from individual short satellite records is challenging. Here we present an approach to merge satellite data sets with the help of a chemistry-climate model nudged to observed meteorology. We use the models' water vapour as a transfer function between data sets that overcomes issues arising from instrument drift and short overlap periods. In the lower stratosphere, our water vapour record extends back to 1988 and water vapour concentrations largely follow tropical tropopause temperatures. Lower and mid-stratospheric long-term trends are negative, and the trends from Boulder are shown not to be globally representative. In the upper stratosphere, our record extends back to 1986 and shows positive long-term trends. The altitudinal differences in the trends are explained by methane oxidation together with a strengthened lower-stratospheric and a weakened upper-stratospheric circulation inferred by this analysis. Our results call into question previous estimates of surface radiative forcing based on presumed global long-term increases in water vapour concentrations in the lower stratosphere. PMID:29263751

Vertical structure of stratospheric water vapour trends derived from merged satellite data.

PubMed

Hegglin, M I; Plummer, D A; Shepherd, T G; Scinocca, J F; Anderson, J; Froidevaux, L; Funke, B; Hurst, D; Rozanov, A; Urban, J; von Clarmann, T; Walker, K A; Wang, H J; Tegtmeier, S; Weigel, K

2014-01-01

Stratospheric water vapour is a powerful greenhouse gas. The longest available record from balloon observations over Boulder, Colorado, USA shows increases in stratospheric water vapour concentrations that cannot be fully explained by observed changes in the main drivers, tropical tropopause temperatures and methane. Satellite observations could help resolve the issue, but constructing a reliable long-term data record from individual short satellite records is challenging. Here we present an approach to merge satellite data sets with the help of a chemistry-climate model nudged to observed meteorology. We use the models' water vapour as a transfer function between data sets that overcomes issues arising from instrument drift and short overlap periods. In the lower stratosphere, our water vapour record extends back to 1988 and water vapour concentrations largely follow tropical tropopause temperatures. Lower and mid-stratospheric long-term trends are negative, and the trends from Boulder are shown not to be globally representative. In the upper stratosphere, our record extends back to 1986 and shows positive long-term trends. The altitudinal differences in the trends are explained by methane oxidation together with a strengthened lower-stratospheric and a weakened upper-stratospheric circulation inferred by this analysis. Our results call into question previous estimates of surface radiative forcing based on presumed global long-term increases in water vapour concentrations in the lower stratosphere.

Water vapour correction of the daily 1 km AVHRR global land dataset: Part I validation and use of the Water Vapour input field

USGS Publications Warehouse

DeFelice, Thomas P.; Lloyd, D.; Meyer, D.J.; Baltzer, T. T.; Piraina, P.

2003-01-01

An atmospheric correction algorithm developed for the 1 km Advanced Very High Resolution Radiometer (AVHRR) global land dataset was modified to include a near real-time total column water vapour data input field to account for the natural variability of atmospheric water vapour. The real-time data input field used for this study is the Television and Infrared Observational Satellite (TIROS) Operational Vertical Sounder (TOVS) Pathfinder A global total column water vapour dataset. It was validated prior to its use in the AVHRR atmospheric correction process using two North American AVHRR scenes, namely 13 June and 28 November 1996. The validation results are consistent with those reported by others and entail a comparison between TOVS, radiosonde, experimental sounding, microwave radiometer, and data from a hand-held sunphotometer. The use of this data layer as input to the AVHRR atmospheric correction process is discussed.

Spectroscopic interaction studies of substituted and unsubstituted copper phthalocyanine with adsorbed organic vapours

NASA Astrophysics Data System (ADS)

Ridhi, R.; Kang, Jasmeen; Saini, G. S. S.; Tripathi, S. K.

2018-05-01

The present study deals with comparing the interaction mechanism of adsorbed organic vapours with Copper Phthalocyanine thin films in its substituted and unsubstituted forms. For this purpose, the variations in vibrational levels of substituted CuPc (CuPcS) functionalized with tetrasulfonic acid tetrasodium salt and unsubstituted CuPc after exposure with methanol and benzene vapours is analyzed. Fourier transform infrared (FTIR) is used to study the interaction behaviour. The bulkier group tetrasulfonic acid tetrasodium salt added to CuPc leads to occupation of more space in the molecular arrangement as compared to unsubstituted CuPc and hence alteration of its properties. FTIR spectra of CuPc and CuPcS before and after vapours exposures highlighted the effect of these vapours on the various bonds and the role of functional group in altering the molecular structure of CuPcS during interaction with adsorbed vapours.

Spacecraft-borne long life cryogenic refrigeration: Status and trends

NASA Technical Reports Server (NTRS)

Johnson, A. L.

1983-01-01

The status of cryogenic refrigerator development intended for, or possibly applicable to, long life spacecraft-borne application is reviewed. Based on these efforts, the general development trends are identified. Using currently projected technology needs, the various trends are compared and evaluated. The linear drive, non-contacting bearing Stirling cycle refrigerator concept appears to be the best current approach that will meet the technology projection requirements for spacecraft-borne cryogenic refrigerators. However, a multiply redundant set of lightweight, moderate life, moderate reliability Stirling cycle cryogenic refrigerators using high-speed linear drive and sliding contact bearings may possibly suffice.

Antifungal activity of clove essential oil and its volatile vapour against dermatophytic fungi.

PubMed

Chee, Hee Youn; Lee, Min Hee

2007-12-01

Antifungal activities of clove essential oil and its volatile vapour against dermatophytic fungi including Candida albicans, Epidermophyton floccosum. Microsporum audouinii, Trichophyton mentagrophytes, and Trichophyton rubrum were investigated. Both clove essential oil and its volatile vapour strongly inhibit spore germination and mycelial growth of the dermatophytic fungi tested. The volatile vapour of clove essential oil showed fungistatic activity whereas direct application of clove essential oil showed fungicidal activity.

Post-Contamination Vapour Hazards from Military Vehicles Contaminated with Thickened and Unthickened GD

DTIC Science & Technology

1979-02-01

The residual vapour hazards from four types of military vehicles previously contaminated with either thickened or unthickened GD have been measured...magnitude of these hazards have been investigated and an assessment made of their relevance to contamination control. It was found that on permeable... contamination had been applied were ineffective in reducing the subsequent vapour hazard; the vapour hazard arising from thickened GD contamination was less

Magnetic refrigeration in space - Practical considerations

NASA Technical Reports Server (NTRS)

Kittel, P.

1980-01-01

Various schemes of using adiabatic demagnetization to provide refrigeration in the 10-1000 mK range are discussed with particular reference to the requirements for use in space. The methods considered are complete demagnetization, isothermal demagnetization, moving magnet demagnetization, and continuous refrigeration. The requirements that are important for use in space are low mass, low power dissipation, high mechanical rigidity, modular design, and ease of use.

Combined cold compressor/ejector helium refrigerator

DOEpatents

Brown, D.P.

1984-06-05

A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

Combined cold compressor/ejector helium refrigerator

DOEpatents

Brown, Donald P.

1985-01-01

A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

Food Safety Practices Linked with Proper Refrigerator Temperatures in Retail Delis.

PubMed

Brown, Laura G; Hoover, Edward Rickamer; Faw, Brenda V; Hedeen, Nicole K; Nicholas, David; Wong, Melissa R; Shepherd, Craig; Gallagher, Daniel L; Kause, Janell R

2018-05-01

Listeria monocytogenes (L. monocytogenes) causes the third highest number of foodborne illness deaths annually. L. monocytogenes contamination of sliced deli meats at the retail level is a significant contributing factor to L. monocytogenes illness. The Centers for Disease Control and Prevention's Environmental Health Specialists Network (EHS-Net) conducted a study to learn more about retail delis' practices concerning L. monocytogenes growth and cross-contamination prevention. This article presents data from this study on the frequency with which retail deli refrigerator temperatures exceed 41°F, the Food and Drug Administration (FDA)-recommended maximum temperature for ready-to-eat food requiring time and temperature control for safety (TCS) (such as retail deli meat). This provision was designed to control bacterial growth in TCS foods. This article also presents data on deli and staff characteristics related to the frequency with which retail delis refrigerator temperatures exceed 41°F. Data from observations of 445 refrigerators in 245 delis showed that in 17.1% of delis, at least one refrigerator was >41°F. We also found that refrigeration temperatures reported in this study were lower than those reported in a related 2007 study. Delis with more than one refrigerator, that lacked refrigerator temperature recording, and had a manager who had never been food safety certified had greater odds of having a refrigerator temperature >41°F. The data from this study suggest that retail temperature control is improving over time. They also identify a food safety gap: some delis have refrigerator temperatures that exceed 41°F. We also found that two food safety interventions were related to better refrigerated storage practices: kitchen manager certification and recording refrigerated storage temperatures. Regulatory food safety programs and the retail industry may wish to consider encouraging or requiring kitchen manager certification and recording refrigerated

Room-temperature storage of medications labeled for refrigeration.

PubMed

Cohen, Victor; Jellinek, Samantha P; Teperikidis, Leftherios; Berkovits, Elliot; Goldman, William M

2007-08-15

Data regarding the recommended maximum duration that refrigerated medications available in hospital pharmacies may be stored safely at room temperature were collected and compiled in a tabular format. During May and June of 2006, the prescribing information for medications labeled for refrigeration as obtained from the supplier were reviewed for data addressing room-temperature storage. Telephone surveys of the products' manufacturers were conducted when this information was not available in the prescribing information. Medications were included in the review if they were labeled to be stored at 2-8 degrees C and purchased by the pharmacy department for uses indicated on the hospital formulary. Frozen antibiotics thawed in the refrigerator and extemporaneously compounded medications were excluded. Information was compiled and arranged in tabular format. The U.S. Pharmacopeia's definition of room temperature (20-25 degrees C [68-77 degrees F]) was used for this review. Of the 189 medications listed in AHFS Drug Information 2006 for storage in a refrigerator, 89 were present in the pharmacy department's refrigerator. Since six manufacturers were unable to provide information for 10 medications, only 79 medications were included in the review. This table may help to avoid unnecessary drug loss and expenditures due to improper storage temperatures. Information regarding the room-temperature storage of 79 medications labeled for refrigerated storage was compiled.

SBIR Grant:No-Vibration Agile Cryogenic Optical Refrigerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Epstein, Richard

2013-04-09

Optical refrigeration is currently the only all-solid-state cryocooling technology that has been demonstrated. Optical cryocoolers are devices that use laser light to cool small crystal or glass cooling elements. The cooling element absorbs the laser light and reradiates it at higher energy, an example of anti-Stokes fluorescence. The dif-ference between the energy of the outgoing and incoming light comes from the thermal energy of the cooling element, which in turn becomes colder. Entitled No-Vibration Agile Cryocoolers using Optical Refrigeration, this Phase I proposal directly addressed the continued development of the optical refrigerator components necessary to transition this scientific breakthrough intomore » National Nu-clear Security Administration (NNSA) sensor applications in line with the objectives of topic 50b. ThermoDynamic Films LLC (TDF), in collaboration with the University of New Mexico (UNM), cooled an optical-refrigerator cooling element comprised of an ytterbium-doped yttrium lithium fluoride (Yb:YLF) crystal from room tempera-ture to 123 K with about 2% efficiency. This is the world record in optical refrigera-tion and an important step toward revolutionizing cryogenic systems for sensor ap-plications. During this period, they also designed and analyzed the crucial elements of a prototype optical refrigerator including the thermal link that connects the cool-ing element with the load.« less

The Seasonal Cycle of Water Vapour on Mars from Assimilation of Thermal Emission Spectrometer Data

NASA Technical Reports Server (NTRS)

Steele, Liam J.; Lewis, Stephen R.; Patel, Manish R.; Montmessin, Franck; Forget, Francois; Smith, Michael D.

2014-01-01

We present for the first time an assimilation of Thermal Emission Spectrometer (TES) water vapour column data into a Mars global climate model (MGCM). We discuss the seasonal cycle of water vapour, the processes responsible for the observed water vapour distribution, and the cross-hemispheric water transport. The assimilation scheme is shown to be robust in producing consistent reanalyses, and the global water vapour column error is reduced to around 2-4 pr micron depending on season. Wave activity is shown to play an important role in the water vapour distribution, with topographically steered flows around the Hellas and Argyre basins acting to increase transport in these regions in all seasons. At high northern latitudes, zonal wavenumber 1 and 2 stationary waves during northern summer are responsible for spreading the sublimed water vapour away from the pole. Transport by the zonal wavenumber 2 waves occurs primarily to the west of Tharsis and Arabia Terra and, combined with the effects of western boundary currents, this leads to peak water vapour column abundances here as observed by numerous spacecraft. A net transport of water to the northern hemisphere over the course of one Mars year is calculated, primarily because of the large northwards flux of water vapour which occurs during the local dust storm around L(sub S) = 240-260deg. Finally, outlying frost deposits that surround the north polar cap are shown to be important in creating the peak water vapour column abundances observed during northern summer.

LOW-GLOBAL-WARMING CHEMICALS AND REFRIGERANT TECHNOLOGIES (ATMOSPHERIC PROTECTION BRANCH, APPCD, NRMRL)

EPA Science Inventory

The Atmospheric Protection Branch's Refrigeration Applications Laboratory has the capability to test several types of refrigeration equipment with various refrigerants. Refrigeration compressors are tested according to the ANSI/ASHRAE 23-1993 Test Standard and under various oper...

Comparison of interaction mechanisms of copper phthalocyanine and nickel phthalocyanine thin films with chemical vapours

NASA Astrophysics Data System (ADS)

Ridhi, R.; Singh, Sukhdeep; Saini, G. S. S.; Tripathi, S. K.

2018-04-01

The present study deals with comparing interaction mechanisms of copper phthalocyanine and nickel phthalocyanine with versatile chemical vapours: reducing, stable aromatic and oxidizing vapours namely; diethylamine, benzene and bromine. The variation in electrical current of phthalocyanines with exposure of chemical vapours is used as the detection parameter for studying interaction behaviour. Nickel phthalocyanine is found to exhibit anomalous behaviour after exposure of reducing vapour diethylamine due to alteration in its spectroscopic transitions and magnetic states. The observed sensitivities of copper phthalocyanine and nickel phthalcyanine films are different in spite of their similar bond numbers, indicating significant role of central metal atom in interaction mechanism. The variations in electronic transition levels after vapours exposure, studied using UV-Visible spectroscopy confirmed our electrical sensing results. Bromine exposure leads to significant changes in vibrational bands of metal phthalocyanines as compared to other vapours.

Compact acoustic refrigerator

DOEpatents

Bennett, G.A.

1992-11-24

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

A cold ejector for closed-cycle helium refrigerators

NASA Technical Reports Server (NTRS)

Johnson, D. L.; Daggett, D. L.

1987-01-01

The test results are presented of an initial cold helium ejector design that can be installed on a closed cycle refrigerator to provide refrigeration at temperatures below 4.2 K. The ejector, test apparatus, instrumentation, and test results are described. Tests were conducted both at room temperature and at cryogenic temperatures to provide operational experience with the ejector as well as for future use in the subsequent design of an ejector that will provide refrigeration at temperatures below 3 K.

Refrigeration arrangement and methods for reducing charge migration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Litch, Andrew D.; Wu, Guolian

A refrigerator appliance including a refrigerant circuit between a condenser, an evaporator, and a compressor that includes two conduits and pressure reducing devices arranged in parallel between the evaporator and the condenser. The appliance also includes a valve system to direct refrigerant through one, both or none of the conduits and pressure reducing devices, and a heat exchanging member in thermal contact with either one pressure reducing device, or one conduit between the pressure reducing device and the valve system.

Hydrophilic structures for condensation management in refrigerator appliances

DOEpatents

Kuehl, Steven John; Vonderhaar, John J; Wu, Guolian; Wu, Mianxue

2014-10-21

A refrigerator appliance that includes a freezer compartment having a freezer compartment door, and a refrigeration compartment having at least one refrigeration compartment door. The appliance further includes a mullion with an exterior surface. The mullion divides the compartments and the exterior surface directs condensation toward a transfer point. The appliance may also include a cabinet that houses the compartments and has two sides, each with an exterior surface. Further, at least one exterior surface directs condensation toward a transfer point.

Realization of an all-solid-state cryocooler using optical refrigeration

NASA Astrophysics Data System (ADS)

Meng, Junwei; Albrecht, Alexander R.; Gragossian, Aram; Lee, Eric; Volpi, Azzurra; Ghasemkhani, Mohammadreza; Hehlen, Markus P.; Epstein, Richard I.; Sheik-Bahae, Mansoor

2018-05-01

Optical refrigeration of rare-earth-doped solids has reached the boiling point of argon, 87 K, and is expected to cool to that of nitrogen, 77 K, in the near future. This technology is poised to pave the way to compact, reliable, and vibrationfree all-solid-state optical cryocoolers. By attaching the Yb:YLF cooling crystal to a cold finger via a double 90° kink thermal link, we have cooled a silicon temperature sensor to below 151 K. An advanced design of the thermal link and the clamshell surrounding the cooled assembly successfully controlled the flow of heat and radiation to allow cooling of a payload to cryogenic temperatures. Key elements of the design were a low-absorption thermal link material, an optimized thermal link geometry, and a spectrally-selective coating of the clamshell.

Transitioning to Low-GWP Alternatives in Transport Refrigeration

EPA Pesticide Factsheets

This fact sheet provides information on low-GWP refrigerant and foam blowing agent alternatives used in transport refrigeration equipment. It discusses HFC alternatives, market trends, challenges to market entry for alternatives, and potential solutions.

THERMODYNAMIC EVALUATION OF FIVE ALTERNATIVE REFRIGERANTS IN VAPOR-COMPRESSION CYCLES

EPA Science Inventory

The paper gives results of a thermodynamic evaluation of five alternative refrigerants in a vapor-compression refrigeration cycle, utilizing throttling, super-heating, and combined throttling and superheating. ive alternative refrigerants (R32, R125, R134a, R143a, and R152a) were...

UV absorption investigation of ferromagnetically filled ultra-thick carbon onions, carriers of the 217.5 nm Interstellar Absorption Feature

NASA Astrophysics Data System (ADS)

Boi, Filippo S.; Zhang, Xiaotian; Ivaturi, Sameera; Liu, Qianyang; Wen, Jiqiu; Wang, Shanling

2017-12-01

Carbon nano-onions (CNOs) are fullerene-like structures which consist of quasi-spherical closed carbon shells. These structures have become a subject of great interest thanks to their characteristic absorption feature of interstellar origin (at 217.5 nm, 4.6 μm-1). An additional extinction peak at 3.8 μm-1 has also been reported and attributed to absorption by graphitic residues between the as-grown CNOs. Here, we report the ultraviolet absorption properties of ultra-thick CNOs filled with FePt3 crystals, which also exhibit two main absorption peaks—features located at 4.58 μm-1 and 3.44 μm-1. The presence of this additional feature is surprising and is attributed to nonmagnetic graphite flakes produced as a by-product in the pyrolysis experiment (as confirmed by magnetic separation methods). Instead, the feature at 4.58 μm-1 is associated with the π-plasmonic resonance of the CNOs structures. The FePt3 filled CNOs were fabricated in situ by an advanced one-step fast process consisting in the direct sublimation and pyrolysis of two molecular precursors, namely, ferrocene and dichloro-cyclooctadiene-platinum in a chemical vapour deposition system. The morphological, structural, and magnetic properties of the as-grown filled CNOs were characterized by a means of scanning and transmission electron microscopy, X-ray diffraction, and magnetometry.

Refrigeration Servicing.

ERIC Educational Resources Information Center

Hamilton, Donald L.; And Others

This self-study course is designed to familiarize Marine enlisted personnel with the services required to be performed on refrigeration equipment. The course contains four study units. Each study unit begins with a general objective, which is a statement of what the student should learn from the unit. The study units are divided into numbered work…

Determination of trace and minor elements in alloys by atomic-absorption spectroscopy using an induction-heated graphite-well furnace as atom source-II.

PubMed

Ashy, M A; Headridge, J B; Sowerbutts, A

1974-06-01

Results are presented for the atomic-absorption spectrophotometric determination of zinc in aluminium and aluminium-silicon alloys, and aluminium, antimony and tin in steels, by means of solid samples dropped into an induction-heated graphite-well furnace to produce the atomic vapour.

OPTIONS FOR REDUCING REFRIGERANT EMISSIONS FROM SUPERMARKET SYSTEMS

EPA Science Inventory

The report was prepared to assist personnel responsible for the design, construction, and maintenance of retail food refrigeration equipment in making knowledgeable decisions regarding the implementation of refrigerant-emissions-reducing practices and technologies. It characteriz...

Energy Efficiency and Environmental Impact Analyses of Supermarket Refrigeration Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, Brian A; Bansal, Pradeep; Zha, Shitong

This paper presents energy and life cycle climate performance (LCCP) analyses of a variety of supermarket refrigeration systems to identify designs that exhibit low environmental impact and high energy efficiency. EnergyPlus was used to model refrigeration systems in a variety of climate zones across the United States. The refrigeration systems that were modeled include the traditional multiplex DX system, cascade systems with secondary loops and the transcritical CO2 system. Furthermore, a variety of refrigerants were investigated, including R-32, R-134a, R-404A, R-1234yf, R-717, and R-744. LCCP analysis was used to determine the direct and indirect carbon dioxide emissions resulting from themore » operation of the various refrigeration systems over their lifetimes. Our analysis revealed that high-efficiency supermarket refrigeration systems may result in up to 44% less energy consumption and 78% reduced carbon dioxide emissions compared to the baseline multiplex DX system. This is an encouraging result for legislators, policy makers and supermarket owners to select low emission, high-efficiency commercial refrigeration system designs for future retrofit and new projects.« less

Analysis of a domestic refrigerator cycle with an ejector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomasek, M.L.; Radermacher, R.

1995-08-01

In this paper, an improved cooling cycle for a conventional domestic refrigerator-freezer utilizing an ejector for vapor precompression is analyzed using an idealized model Its energy efficiency is compared to that of the conventional refrigerator-freezer system. Emphasis is placed on off-design conditions. The ejector-enhanced refrigeration cycle consists of two evaporators that operate at different pressure and temperature levels. The ejector combines the vapor flows exiting the two evaporators into one at an intermediate pressure level The ejector cycle gives an increase of up to 12.4% in the coefficient of performance (COP) compared to that of a standard refrigerator-freezer refrigeration cycle.more » The analysis includes calculations on the optimum throat diameters of the ejector. The investigation on the off-design performance of the ejector cycle shows little dependency of energy consumption on constant ejector throat diameters.« less

Impact of major volcanic eruptions on stratospheric water vapour

NASA Astrophysics Data System (ADS)

Löffler, Michael; Brinkop, Sabine; Jöckel, Patrick

2016-05-01

Volcanic eruptions can have a significant impact on the Earth's weather and climate system. Besides the subsequent tropospheric changes, the stratosphere is also influenced by large eruptions. Here changes in stratospheric water vapour after the two major volcanic eruptions of El Chichón in Mexico in 1982 and Mount Pinatubo on the Philippines in 1991 are investigated with chemistry-climate model simulations. This study is based on two simulations with specified dynamics of the European Centre for Medium-Range Weather Forecasts Hamburg - Modular Earth Submodel System (ECHAM/MESSy) Atmospheric Chemistry (EMAC) model, performed within the Earth System Chemistry integrated Modelling (ESCiMo) project, of which only one includes the long-wave volcanic forcing through prescribed aerosol optical properties. The results show a significant increase in stratospheric water vapour induced by the eruptions, resulting from increased heating rates and the subsequent changes in stratospheric and tropopause temperatures in the tropics. The tropical vertical advection and the South Asian summer monsoon are identified as sources for the additional water vapour in the stratosphere. Additionally, volcanic influences on tropospheric water vapour and El Niño-Southern Oscillation (ENSO) are evident, if the long-wave forcing is strong enough. Our results are corroborated by additional sensitivity simulations of the Mount Pinatubo period with reduced nudging and reduced volcanic aerosol extinction.

Influence of Oil on Refrigerant Evaporator Performance

NASA Astrophysics Data System (ADS)

Kim, Jong-Soo; Nagata, Karsuya; Katsuta, Masafumi; Tomosugi, Hiroyuki; Kikuchi, Kouichiro; Horichi, Toshiaki

In vapor compression refrigeration system using oil-lubricated compressors, some amount of oil is always circulated through the system. Oil circulation can have a significant influence on the evaporator performance of automotive air conditioner which is especially required to cool quickly the car interior after a period standing in the sun. An experimental investigation was carried out an electrically heated horizontal tube to measure local heat transfer coefficients for various flow rates and heat fluxes during forced convection boiling of pure refrigerant R12 and refrigerant-oil mixtures (0-11% oil concentration by weight) and the results were compared with oil free performance. Local heat transfer coefficients increased at the region of low vapor quality by the addition of oil. On the other hand, because the oil-rich liquid film was formed on the heat transfer surface, heat transfer coefficients gradually decreased as the vapor quality became higher. Average heat transfer coefficient reached a maximum at about 4% oil concentration and this trend agreed well with the results of Green and Furse. Previous correlations, using the properties of the refrigerant-oil mixture, could not predict satisfactorily the local heat transfer coefficients data. New correlation modified by oil concentration factor was developed for predicting the corresponding heat transfer coefficient for refrigerant-oil mixture convection boiling. The maximum percent deviation between predicted and measured heat transfer coefficient was within ±30%.

PERFORMANCE OF A TWO-CYCLE REFRIGERATOR/FREEZER USING HFC REFRIGERANTS

EPA Science Inventory

A two-cycle 18 ft3 (0.51 m3) refrigerator/freezer (R/F) was tested utilizing American National Standards Institute (ANSI)/AHAM (1988) standards for energy consumption testing. A 34.9% energy consumption reduction was realized. This work presents a proven method of reducing the ...

46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids any...

46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids any...

48 CFR 52.223-12 - Refrigeration Equipment and Air Conditioners.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 2 2013-10-01 2013-10-01 false Refrigeration Equipment... Provisions and Clauses 52.223-12 Refrigeration Equipment and Air Conditioners. As prescribed in 23.804(b), insert the following clause: Refrigeration Equipment and Air Conditioners (MAY 1995) The Contractor shall...

46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids any...

48 CFR 52.223-12 - Refrigeration Equipment and Air Conditioners.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false Refrigeration Equipment... Provisions and Clauses 52.223-12 Refrigeration Equipment and Air Conditioners. As prescribed in 23.804(b), insert the following clause: Refrigeration Equipment and Air Conditioners (MAY 1995) The Contractor shall...

48 CFR 52.223-12 - Refrigeration Equipment and Air Conditioners.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 2 2014-10-01 2014-10-01 false Refrigeration Equipment... Provisions and Clauses 52.223-12 Refrigeration Equipment and Air Conditioners. As prescribed in 23.804(b), insert the following clause: Refrigeration Equipment and Air Conditioners (MAY 1995) The Contractor shall...

48 CFR 52.223-12 - Refrigeration Equipment and Air Conditioners.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Refrigeration Equipment... Provisions and Clauses 52.223-12 Refrigeration Equipment and Air Conditioners. As prescribed in 23.804(b), insert the following clause: Refrigeration Equipment and Air Conditioners (MAY 1995) The Contractor shall...

46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids any...

46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids any...

48 CFR 52.223-12 - Refrigeration Equipment and Air Conditioners.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 2 2012-10-01 2012-10-01 false Refrigeration Equipment... Provisions and Clauses 52.223-12 Refrigeration Equipment and Air Conditioners. As prescribed in 23.804(b), insert the following clause: Refrigeration Equipment and Air Conditioners (MAY 1995) The Contractor shall...

Levels of selected carcinogens and toxicants in vapour from electronic cigarettes.

PubMed

Goniewicz, Maciej Lukasz; Knysak, Jakub; Gawron, Michal; Kosmider, Leon; Sobczak, Andrzej; Kurek, Jolanta; Prokopowicz, Adam; Jablonska-Czapla, Magdalena; Rosik-Dulewska, Czeslawa; Havel, Christopher; Jacob, Peyton; Benowitz, Neal

2014-03-01

Electronic cigarettes, also known as e-cigarettes, are devices designed to imitate regular cigarettes and deliver nicotine via inhalation without combusting tobacco. They are purported to deliver nicotine without other toxicants and to be a safer alternative to regular cigarettes. However, little toxicity testing has been performed to evaluate the chemical nature of vapour generated from e-cigarettes. The aim of this study was to screen e-cigarette vapours for content of four groups of potentially toxic and carcinogenic compounds: carbonyls, volatile organic compounds, nitrosamines and heavy metals. Vapours were generated from 12 brands of e-cigarettes and the reference product, the medicinal nicotine inhaler, in controlled conditions using a modified smoking machine. The selected toxic compounds were extracted from vapours into a solid or liquid phase and analysed with chromatographic and spectroscopy methods. We found that the e-cigarette vapours contained some toxic substances. The levels of the toxicants were 9-450 times lower than in cigarette smoke and were, in many cases, comparable with trace amounts found in the reference product. Our findings are consistent with the idea that substituting tobacco cigarettes with e-cigarettes may substantially reduce exposure to selected tobacco-specific toxicants. E-cigarettes as a harm reduction strategy among smokers unwilling to quit, warrants further study. (To view this abstract in Polish and German, please see the supplementary files online.).

Mixing of multiple metal vapours into an arc plasma in gas tungsten arc welding of stainless steel

NASA Astrophysics Data System (ADS)

Park, Hunkwan; Trautmann, Marcus; Tanaka, Keigo; Tanaka, Manabu; Murphy, Anthony B.

2017-11-01

A computational model of the mixing of multiple metal vapours, formed by vaporization of the surface of an alloy workpiece, into the thermal arc plasma in gas tungsten arc welding (GTAW) is presented. The model incorporates the combined diffusion coefficient method extended to allow treatment of three gases, and is applied to treat the transport of both chromium and iron vapour in the helium arc plasma. In contrast to previous models of GTAW, which predict that metal vapours are swept away to the edge of the arc by the plasma flow, it is found that the metal vapours penetrate strongly into the arc plasma, reaching the cathode region. The predicted results are consistent with published measurements of the intensity of atomic line radiation from the metal vapours. The concentration of chromium vapour is predicted to be higher than that of iron vapour due to its larger vaporization rate. An accumulation of chromium vapour is predicted to occur on the cathode at about 1.5 mm from the cathode tip, in agreement with published measurements. The arc temperature is predicted to be strongly reduced due to the strong radiative emission from the metal vapours. The driving forces causing the diffusion of metal vapours into the helium arc are examined, and it is found that diffusion due to the applied electric field (cataphoresis) is dominant. This is explained in terms of large ionization energies and the small mass of helium compared to those of the metal vapours.

Kinetic model of water vapour adsorption by gluten-free starch

NASA Astrophysics Data System (ADS)

Ocieczek, Aneta; Kostek, Robert; Ruszkowska, Millena

2015-01-01

This study evaluated the kinetics of water vapour adsorption on the surface of starch molecules derived from wheat. The aim of the study was to determine an equation that would allow estimation of water content in tested material in any timepoint of the adsorption process aimed at settling a balance with the environment. An adsorption isotherm of water vapour on starch granules was drawn. The parameters of the Guggenheim, Anderson, and De Boer equation were determined by characterizing the tested product and adsorption process. The equation of kinetics of water vapour adsorption on the surface of starch was determined based on the Guggenheim, Anderson, and De Boer model describing the state of equilibrium and on the model of a first-order linear inert element describing the changes in water content over time.

Mechanism of two-step vapour-crystal nucleation in a pore

NASA Astrophysics Data System (ADS)

van Meel, J. A.; Liu, Y.; Frenkel, D.

2015-09-01

We present a numerical study of the effect of hemispherical pores on the nucleation of Lennard-Jones crystals from the vapour phase. As predicted by Page and Sear, there is a narrow range of pore radii, where vapour-liquid nucleation can become a two-step process. A similar observation was made for different pore geometries by Giacomello et al. We find that the maximum nucleation rate depends on both the size and the adsorption strength of the pore. Moreover, a poe can be more effective than a planar wall with the same strength of attraction. Pore-induced vapour-liquid nucleation turns out to be the rate-limiting step for crystal nucleation. This implies that crystal nucleation can be enhanced by a judicious choice of the wetting properties of a microporous nucleating agent.

Crohn's disease and early exposure to domestic refrigeration.

PubMed

Malekzadeh, Fatemeh; Alberti, Corinne; Nouraei, Mehdi; Vahedi, Homayoon; Zaccaria, Isabelle; Meinzer, Ulrich; Nasseri-Moghaddam, Siavosh; Sotoudehmanesh, Rasoul; Momenzadeh, Sara; Khaleghnejad, Reza; Rashtak, Shahrooz; Olfati, Golrokh; Malekzadeh, Reza; Hugot, Jean-Pierre

2009-01-01

Environmental risk factors playing a causative role in Crohn's Disease (CD) remain largely unknown. Recently, it has been suggested that refrigerated food could be involved in disease development. We thus conducted a pilot case control study to explore the association of CD with the exposure to domestic refrigeration in childhood. Using a standard questionnaire we interviewed 199 CD cases and 207 age-matched patients with irritable bowel syndrome (IBS) as controls. Cases and controls were followed by the same gastroenterologists of tertiary referral clinics in Tehran, Iran. The questionnaire focused on the date of the first acquisition of home refrigerator and freezer. Data were analysed by a multivariate logistic model. The current age was in average 34 years in CD cases and the percentage of females in the case and control groups were respectively 48.3% and 63.7%. Patients were exposed earlier than controls to the refrigerator (X2 = 9.9, df = 3, P = 0.04) and refrigerator exposure at birth was found to be a risk factor for CD (OR = 2.08 (95% CI: 1.01-4.29), P = 0.05). Comparable results were obtained looking for the exposure to freezer at home. Finally, among the other recorded items reflecting the hygiene and comfort at home, we also found personal television, car and washing machine associated with CD. This study supports the opinion that CD is associated with exposure to domestic refrigeration, among other household factors, during childhood.

Refrigeration Playbook. Heat Reclaim; Optimizing Heat Rejection and Refrigeration Heat Reclaim for Supermarket Energy Conservation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reis, Chuck; Nelson, Eric; Armer, James

The purpose of this playbook and accompanying spreadsheets is to generalize the detailed CBP analysis and to put tools in the hands of experienced refrigeration designers to evaluate multiple applications of refrigeration waste heat reclaim across the United States. Supermarkets with large portfolios of similar buildings can use these tools to assess the impact of large-scale implementation of heat reclaim systems. In addition, the playbook provides best practices for implementing heat reclaim systems to achieve the best long-term performance possible. It includes guidance on operations and maintenance as well as measurement and verification.

Are central venous catheter tip cultures reliable after 6-day refrigeration?

PubMed

Bouza, Emilio; Guembe, Maria; Gómez, Haydee; Martín-Rabadán, Pablo; Rivera, Marisa; Alcalá, Luis

2009-07-01

Present guidelines recommend culturing only central venous catheter (CVC) tips from patients with suspected catheter-related bloodstream infection (CR-BSI). However, a high proportion of these suspicions are not confirmed. Moreover, CVC tip culture increases laboratory workload, and reports of colonization may be meaningless or misleading for the clinician. Our working hypothesis was that CVC tips should be refrigerated and cultured only in patients with positive blood cultures. We evaluated the effect of 6-day refrigeration of 215 CVC tips. We selected all the catheters with a significant count according to the Maki's roll-plate technique and randomly assigned them to 2 groups. In group A, the catheters were recultured after 24 h of refrigeration, and in group B, the catheters were recultured after 6 days more of refrigeration, so that the refrigeration time evaluated would be of 6 days. The yield of refrigerated CVC tips that grow significant colony counts of primary culture in group B was compared with the yield of refrigerated catheter tips in group A. The difference showed that 6-day refrigeration reduced the number of significant CVCs by 15.2%. Only 61 CVCs were obtained from patients with CR-BSI, and in most of them, blood cultures were already positive before CVC culture, so only 0.91% of the CR-BSI episodes would have been misdiagnosed as culture negative after refrigeration. Refrigeration of CVC tips sent for culture and culturing only those from patients with positive blood cultures reduce the workload in the microbiology laboratory without misdiagnosing CR-BSI.

An adiabatic demagnetization refrigerator for SIRTF

NASA Technical Reports Server (NTRS)

Timbie, P. T.; Bernstein, G. M.; Richards, P. L.

1989-01-01

An adiabatic demagnetization refrigerator (ADR) has been proposed to cool bolometric infrared detectors on the multiband imaging photometer of the Space Infrared Telescope Facility (SIRTF). One such refrigerator has been built which uses a ferric ammonium alum salt pill suspended by nylon threads in a 3-T solenoid. The resonant modes of this suspension are above 100 Hz. The heat leak to the salt pill is less than 0.5 microW. The system has a hold time at 0.1K of more than 12 h. The cold stage temperature is regulated with a feedback loop that controls the magnetic field. A second, similar refrigerator is being built at a SIRTF prototype to fly on a ballon-borne telescope. It will use a ferromagnetic shield. The possibility of using a high-Tc solenoid-actuated heat switch is also discussed.

THE REFRIGERATION TREATMENT OF CHRONIC OSTEOMYELITIS

PubMed Central

Bingham, Robert

1951-01-01

Systemic penicillin therapy plus refrigeration at the site of the lesion, with operation if necessary, was used in the treatment of chronic osteomyelitis. Nine patients with disease of long standing were treated. For three, bed rest, chemotherapy and refrigeration were sufficient. Surgical treatment in addition was carried out in six cases. Operations consisted of unroofing the abscess cavity, multiple drilling for sievelike perforation of the abscessed bone, and primary suture of the incision. Solutions of penicillin, 500 to 1,000 units per cubic centimeter, were used for local irrigation at the time of closure. In all cases the lesions healed and there was no recurrence within a period of two years. The period of hospitalization did not exceed 14 days in any case. Refrigeration of the infected area before and after operation reduced pain, swelling, infection and toxemia. PMID:14801722

Load leveling on industrial refrigeration systems

NASA Astrophysics Data System (ADS)

Bierenbaum, H. S.; Kraus, A. D.

1982-01-01

A computer model was constructed of a brewery with a 2000 horsepower compressor/refrigeration system. The various conservation and load management options were simulated using the validated model. The savings available for implementing the most promising options were verified by trials in the brewery. Result show that an optimized methodology for implementing load leveling and energy conservation consisted of: (1) adjusting (or tuning) refrigeration systems controller variables to minimize unnecessary compressor starts, (2) The primary refrigeration system operating parameters, compressor suction pressure, and discharge pressure are carefully controlled (modulated) to satisfy product quality constraints (as well as in-process material cooling rates and temperature levels) and energy evaluating the energy cost savings associated with reject heat recovery, and (4) a decision is made to implement the reject heat recovery system based on a cost/benefits analysis.

Mixed garnet laser crystals for water vapour DIAL transmitter

NASA Astrophysics Data System (ADS)

Treichel, Rainer; Czeranowsky, Christoph; Ileri, Bilge; Petermann, Klaus; Huber, Günter

2017-11-01

There are more or less well established technologies such as the optical-parametric-oscillator (OPO), the Raman-laser, and the Ti-Sapphire laser, which are able to emit laser light in the region of the water vapour absorption lines. For WALES the regions of about 935 nm, 942 nm, and 944 nm have been identified as the most suitable wavelength ranges. However, each of these laser designs is highly sophisticated. Current baseline for WALES is the Ti-Sapphire laser. A fourth possibility to achieve these wavelength ranges is to shift the groundstate laser lines (938 nm and 946 nm) of the Nd:YAG laser by replacing Aluminium and Yttrium by other rare earth elements. Changes of the host lattice characteristics lead to a shift of the upper and lower laser levels. These modified crystals are summarized under the name of "Mixed Garnet" crystals. Only the Mixed Garnet lasers can be pumped directly with diode laser and use a direct approach to generate the required laser pulses without frequency conversion. Therefore no additional non-linear crystals are needed and a higher electric to optical efficiency is expected as well as single frequency operation using spectral tuning elements like etalons. Such lasers have the great potential to fulfil the requirements and to become the preferred transmitter concept for WALES as well as for follow up missions. Within a ESA study several crystal compositions have been grown, spectrally characterised and analysed. Absorbed space radiation energy in the crystal lattice causes colour centres, which can reabsorb the pump and laser wavelength and consequently reduce the laser gain considerably. Co-dopants such as Chromium and Cerium are able to suppress the colour centres and are candidates for effective radiation hardening. The results of the crystal tuning, the co-doping with different radiation hardeners and the radiation tests will be presented. There applicability for a space based water vapour DIAL transmitter will be discussed.

Floating loop method for cooling integrated motors and inverters using hot liquid refrigerant

DOEpatents

Hsu, John S.; Ayers, Curtis W.; Coomer, Chester; Marlino, Laura D.

2007-03-20

A method for cooling vehicle components using the vehicle air conditioning system comprising the steps of: tapping the hot liquid refrigerant of said air conditioning system, flooding a heat exchanger in the vehicle component with said hot liquid refrigerant, evaporating said hot liquid refrigerant into hot vapor refrigerant using the heat from said vehicle component, and returning said hot vapor refrigerant to the hot vapor refrigerant line in said vehicle air conditioning system.

Overview of RICOR tactical cryogenic refrigerators for space missions

NASA Astrophysics Data System (ADS)

Riabzev, Sergey; Filis, Avishai; Livni, Dorit; Regev, Itai; Segal, Victor; Gover, Dan

2016-05-01

Cryogenic refrigerators represent a significant enabling technology for Earth and Space science enterprises. Many of the space instruments require cryogenic refrigeration to enable the use of advanced detectors to explore a wide range of phenomena from space. RICOR refrigerators involved in various space missions are overviewed in this paper, starting in 1994 with "Clementine" Moon mission, till the latest ExoMars mission launched in 2016. RICOR tactical rotary refrigerators have been incorporated in many space instruments, after passing qualification, life time, thermal management testing and flight acceptance. The tactical to space customization framework includes an extensive characterization and qualification test program to validate reliability, the design of thermal interfacing with a detector, vibration export control, efficient heat dissipation in a vacuum environment, robustness, mounting design, compliance with outgassing requirements and strict performance screening. Current RICOR development is focused on dedicated ultra-long-life, highly reliable, space cryogenic refrigerator based on a Pulse Tube design

Oxygen chemisorption compressor study for cryogenic J-T refrigeration

NASA Technical Reports Server (NTRS)

Jones, Jack A.; Blue, Gary D.

1987-01-01

Over twenty potentially reversible heat-powered oxide reactions have been studied and/or tested to determine their potential use as thermochemical oxygen compressors for cryogenic J-T LO2 refrigerators. One gas-solid compound family, Pr(1-n)Ce(n)O(x), proved to be completely reversible with fast kinetics for all pressure ranges tested below 650 C. With a heat-powered charcoal/methane physical adsorption upper stage and a Pr(1-n)Ce(n)O(x) chemisorption lower stage, temperatures should be attainable in the 55-80 K range for less power and over five times less weight than for charcoal/nitrogen sorption refrigeration systems. Total system power requirements with a hydride chemisorption lower stage (10 K to 7 K minimum) are about three times less than any mechanical refrigerator, and spacecraft refrigeration weights are about twenty times less. Due to the lack of wear-related moving parts in sorption refrigerators, life expectancy is at least ten years, and there essentially no vibration.

49 CFR 173.5b - Portable and mobile refrigeration systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Portable and mobile refrigeration systems. 173.5b...-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS General § 173.5b Portable and mobile refrigeration... refrigeration systems, which may or may not be permanently mounted to a transport vehicle, used for agricultural...

49 CFR 173.5b - Portable and mobile refrigeration systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 2 2012-10-01 2012-10-01 false Portable and mobile refrigeration systems. 173.5b...-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS General § 173.5b Portable and mobile refrigeration... refrigeration systems, which may or may not be permanently mounted to a transport vehicle, used for agricultural...

49 CFR 173.5b - Portable and mobile refrigeration systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Portable and mobile refrigeration systems. 173.5b...-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS General § 173.5b Portable and mobile refrigeration... refrigeration systems, which may or may not be permanently mounted to a transport vehicle, used for agricultural...

Effects of overnight refrigeration on the microscopic evaluation of sputum.

PubMed Central

Penn, R L; Silberman, R

1984-01-01

Microscopic evaluation of sputum permits selection of specimens suitable for culture, assessment of likely pathogens, and the best interpretation of culture results. We prospectively evaluated 50 sputum specimens which were promptly submitted to our clinical laboratory; smears and cultures were performed both immediately and after 20 h of refrigeration. Specimens were grouped according to the numbers of squamous epithelial cells and neutrophils per low-power field present on coded Gram-stained smears. The numbers of bacteria in five oil immersion fields were used to characterize smears for predominant, mixed, or scanty forms. After refrigeration, only three specimens changed group from a definite loss of squamous epithelial cells, and only two changed group from a definite loss of neutrophils. Based on cellular composition, the majority of samples would have been processed identically both before and after refrigeration. In contrast, organism forms detected on smears and their relative quantities were dramatically altered after refrigeration. A predominant smear form was gained in 11 and lost in 8 refrigerated specimens. The frequent changes on smears observed overall resulted from both increases and decreases in numbers of bacteria and yeasts. The majority of sputum culture results were insignificantly affected by the refrigeration of specimens. We conclude that 20 h of refrigeration renders sputum useless for the microscopic evaluation of potential pathogens and the subsequent interpretation of culture results. However, overnight refrigeration does not affect the determination from smears of sputum suitability for culture based on cellular composition. PMID:6699145

Human semen refrigeration at + 4 degrees C: bio-kinetic characteristics.

PubMed

Dondero, Franco; Rossi, Tiziana; Delfino, Michele; Imbrogno, Norina; Cannistrà, Stefania; Mazzilli, Fernando

2006-01-01

The aim of our study was to evaluate the bio-kinetic characteristics of human semen refrigerated for different periods and to compare the effects of refrigeration at +4 degrees C against cryopreservation of human sperm at -196 degrees C. Semen was obtained from 30 male partners of infertile couples (infertile subjects) with the following semen profile: sperm count >or=10 x 10(6)/ml; progressive motility >or=20%; atypical forms <70% and white blood cells <1.0 x 10(6)/ml. Fifteen normospermic subjects were also selected as controls (control subjects). The following tests were carried out on basal, refrigerated and cryopreserved sperm: a) sperm kinetic properties (by Superimposed Image Analysis System); b) the Hypoosmotic Viability Test (HVT) (combined Hypoosmotic Swelling and Viability Test). The results of the study showed that the percentage recovery of kinetic properties and of HVT were optimum for up to 48 h. After refrigeration for 72 h, a drastic decrease in straight motility recovery was observed. No significant differences were observed between cryopreservation and refrigeration at +4 degrees C for 48 h for motility or HVT recoveries in samples from control subjects. However, in infertile subjects, a significant decrease in straight progressive motility and HVT recoveries was observed in cryopreserved samples compared to those refrigerated for 48 h. Neither refrigeration nor cryopreservation led to the growth of pathogenic bacteria in any of the cases studied. Based on the above results, refrigeration could represent a useful alternative to the cryopreservation method.

Strong water absorption in the dayside emission spectrum of the planet HD 189733b.

PubMed

Grillmair, Carl J; Burrows, Adam; Charbonneau, David; Armus, Lee; Stauffer, John; Meadows, Victoria; van Cleve, Jeffrey; von Braun, Kaspar; Levine, Deborah

2008-12-11

Recent observations of the extrasolar planet HD 189733b did not reveal the presence of water in the emission spectrum of the planet. Yet models of such 'hot-Jupiter' planets predict an abundance of atmospheric water vapour. Validating and constraining these models is crucial to understanding the physics and chemistry of planetary atmospheres in extreme environments. Indications of the presence of water in the atmosphere of HD 189733b have recently been found in transmission spectra, where the planet's atmosphere selectively absorbs the light of the parent star, and in broadband photometry. Here we report the detection of strong water absorption in a high-signal-to-noise, mid-infrared emission spectrum of the planet itself. We find both a strong downturn in the flux ratio below 10 microm and discrete spectral features that are characteristic of strong absorption by water vapour. The differences between these and previous observations are significant and admit the possibility that predicted planetary-scale dynamical weather structures may alter the emission spectrum over time. Models that match the observed spectrum and the broadband photometry suggest that heat redistribution from the dayside to the nightside is weak. Reconciling this with the high nightside temperature will require a better understanding of atmospheric circulation or possible additional energy sources.

Displacer Diameter Effect in Displacer Pulse Tube Refrigerator

NASA Astrophysics Data System (ADS)

Zhu, Shaowei

2017-12-01

Gas driving displacer pulse tube refrigerators are one of the work recovery type of pulse tube refrigerators whose theoretical efficiency is the same as Stirling refrigerators'. Its cooling power is from the displacement of the displacer. Displace diameter, rod diameter and pressure drop of the regenerator influence the displacement, which are investigated by numerical simulation. It is shown that the displacement ratio of the displacer over the piston is almost not affected by the displacer diameter at the same rod diameter ratio, or displacer with different diameters almost has the same performance.

Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

DOEpatents

Gschneidner, Jr., Karl A.; Takeya, Hiroyuki

1995-10-31

A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd.sub.0.54 Er.sub.0.46)AlNi alloys having a relatively constant .DELTA.Tmc over a wide temperature range.

Being everything to anyone: Applicability of thermoacoustic technology in the commercial refrigeration market

NASA Astrophysics Data System (ADS)

Poese, Matthew E.; Smith, Robert W. M.; Garrett, Steven L.

2005-09-01

This talk will compare electrodynamically driven thermoacoustic refrigeration technology to some common implementations of low-lift vapor-compression technology. A rudimentary explanation of vapor-compression refrigeration will be presented along with some of the implementation problems faced by refrigeration engineers using compressor-based systems. These problems include oil management, compressor slugging, refrigerant leaks and the environmental impact of refrigerants. Recently, the method of evaluating this environmental impact has been codified to include the direct effects of the refrigerants on global warming as well as the so-called ``indirect'' warming impact of the carbon dioxide released during the generation (at the power plant) of the electrical power consumed by the refrigeration equipment. It is issues like these that generate commercial interest in an alternative refrigeration technology. However, the requirements of a candidate technology for adoption in a mature and risk-averse commercial refrigeration industry are as hard to divine as they are to meet. Also mentioned will be the state of other alternative refrigeration technologies like free-piston Stirling, thermoelectric and magnetocaloric as well as progress using vapor compression technology with alternative refrigerants like hydrocarbons and carbon dioxide.

Photovoltaic refrigeration application: Assessment of the near-term market

NASA Technical Reports Server (NTRS)

Rosenblum, L.; Bifano, W. J.; Poley, W. A.; Scudder, L. R.

1977-01-01

This foreign and domestic market assessment was performed as part of the Tests and Applications Project being conducted by NASA-LeRC as part of the Department of Energy's (DOE) National Photovoltaic Program. One of the objectives of that program was to stimulate the demand for photovoltaic power systems so that appropriate markets would be developed in concert with the increasing photovoltaic production capacity. The refrigeration application represented a possible market for photovoltaics; hence, a brief survey of potential applications was conducted. Both refrigerators and refrigeration systems were considered in the assessment although the primary emphasis is on refrigerators of 9 cu ft of less. Three user sectors were examined: (1) government, (2) commercial/institutional, and (3) general public.

Performance characteristics of low global warming potential R134a alternative refrigerants in ejector-expansion refrigeration system

NASA Astrophysics Data System (ADS)

Mishra, Shubham; Sarkar, Jahar

2016-12-01

Performance assessment of ejector-expansion vapor compression refrigeration system with eco-friendly R134a alternative refrigerants (R152a, R1234yf, R600a, R600, R290, R161, R32, and propylene) is presented for air-conditioning application. Ejector has been modeled by considering experimental data based correlations of component efficiencies to take care of all irreversibilities. Ejector area ratio has been optimized based on maximum coefficient of performance (COP) for typical air-conditioner operating temperatures. Selected refrigerants have been compared based on area ratio, pressure lift ratio, entrainment ratio, COP, COP improvement and volumetric cooling capacity. Effects of normal boiling point and critical point on the performances have been studied as well. Using ejector as an expansion device, maximum improvement in COP is noted in R1234yf (10.1%), which reduces the COP deviation with R134a (4.5% less in basic cycle and 2.5% less in ejector cycle). Hence, R1234yf seems to be best alternative for ejector expansion system due to its mild flammability and comparable volumetric capacity and cooling COP. refrigerant R161 is superior to R134a in terms of both COP and volumetric cooling capacity, although may be restricted for low capacity application due to its flammability.

Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

DOEpatents

Gschneidner, K.A. Jr.; Takeya, Hiroyuki

1995-10-31

A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd{sub 0.54}Er{sub 0.46})AlNi alloys having a relatively constant {Delta}Tmc over a wide temperature range. 16 figs.

Utilizing Thermal Mass in Refrigerated Display Cases to Reduce Peak Demand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, Brian A; Kuruganti, Teja; Nutaro, James J

The potential to store energy within refrigerated food products presents convenience store and supermarket operators with an opportunity to participate in utility sponsored demand response programs, whereby electricity usage can be shifted or reduced during peak periods. To determine the feasibility of reducing peak demand by shifting the refrigeration load to off-peak times, experimental and analytical analyses were performed. Simulated product, consisting of one-pint containers filled with a 50% ethylene glycol and 50% water solution, were stored in a medium-temperature vertical open refrigerated display case. Product temperature rise as a function of time was determined by turning off the refrigerationmore » to the display case, while product temperature pull-down time was subsequently determined by turning on the refrigeration to the display case. It was found that the thermal mass of the product in a medium-temperature display case was such that during a 2.5 hour period with no refrigeration, the average product temperature increased by 5.5 C. In addition, it took approximately 3.5 hours for the product to recover to its initial temperature after the refrigeration was turned on. Transient heat conduction analyses for one-dimensional objects is in good agreement with the experimental results obtained in this study. From the analysis, it appears that the thermal mass of the stored product in refrigerated display cases is sufficient to allow product temperatures to safely drift for a significant time under reduced refrigeration system operation. Thus, strategies for shifting refrigeration system electrical demand can be developed. The use of an advanced refrigeration system controller that can respond to utility signals can enable demand shifting with minimal impact.« less

Quantum heat engines and refrigerators: continuous devices.

PubMed

Kosloff, Ronnie; Levy, Amikam

2014-01-01

Quantum thermodynamics supplies a consistent description of quantum heat engines and refrigerators up to a single few-level system coupled to the environment. Once the environment is split into three (a hot, cold, and work reservoir), a heat engine can operate. The device converts the positive gain into power, with the gain obtained from population inversion between the components of the device. Reversing the operation transforms the device into a quantum refrigerator. The quantum tricycle, a device connected by three external leads to three heat reservoirs, is used as a template for engines and refrigerators. The equation of motion for the heat currents and power can be derived from first principles. Only a global description of the coupling of the device to the reservoirs is consistent with the first and second laws of thermodynamics. Optimization of the devices leads to a balanced set of parameters in which the couplings to the three reservoirs are of the same order and the external driving field is in resonance. When analyzing refrigerators, one needs to devote special attention to a dynamical version of the third law of thermodynamics. Bounds on the rate of cooling when Tc→0 are obtained by optimizing the cooling current. All refrigerators as Tc→0 show universal behavior. The dynamical version of the third law imposes restrictions on the scaling as Tc→0 of the relaxation rate γc and heat capacity cV of the cold bath.

Room-temperature semiconductor heterostructure refrigeration

NASA Astrophysics Data System (ADS)

Chao, K. A.; Larsson, Magnus; Mal'shukov, A. G.

2005-07-01

With the proper design of semiconductor tunneling barrier structures, we can inject low-energy electrons via resonant tunneling, and take out high-energy electrons via a thermionic process. This is the operation principle of our semiconductor heterostructure refrigerator (SHR) without the need of applying a temperature gradient across the device. Even for the bad thermoelectric material AlGaAs, our calculation shows that at room temperature, the SHR can easily lower the temperature by 5-7K. Such devices can be fabricated with the present semiconductor technology. Besides its use as a kitchen refrigerator, the SHR can efficiently cool microelectronic devices.

Unsaturation of vapour pressure inside leaves of two conifer species

DOE PAGES

Cernusak, Lucas A.; Ubierna, Nerea; Jenkins, Michael W.; ...

2018-05-16

Stomatal conductance (g s) impacts both photosynthesis and transpiration, and is therefore fundamental to the global carbon and water cycles, food production, and ecosystem services. Mathematical models provide the primary means of analysing this important leaf gas exchange parameter. A nearly universal assumption in such models is that the vapour pressure inside leaves (e i) remains saturated under all conditions. The validity of this assumption has not been well tested, because so far e i cannot be measured directly. Here, we test this assumption using a novel technique, based on coupled measurements of leaf gas exchange and the stable isotopemore » compositions of CO 2 and water vapour passing over the leaf. We applied this technique to mature individuals of two semiarid conifer species. In both species, e i routinely dropped below saturation when leaves were exposed to moderate to high air vapour pressure deficits. Typical values of relative humidity in the intercellular air spaces were as low 0.9 in Juniperus monosperma and 0.8 in Pinus edulis. These departures of e i from saturation caused significant biases in calculations of g s and the intercellular CO 2 concentration. Thus, our results refute the longstanding assumption of saturated vapour pressure in plant leaves under all conditions.« less

Unsaturation of vapour pressure inside leaves of two conifer species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cernusak, Lucas A.; Ubierna, Nerea; Jenkins, Michael W.

Stomatal conductance (g s) impacts both photosynthesis and transpiration, and is therefore fundamental to the global carbon and water cycles, food production, and ecosystem services. Mathematical models provide the primary means of analysing this important leaf gas exchange parameter. A nearly universal assumption in such models is that the vapour pressure inside leaves (e i) remains saturated under all conditions. The validity of this assumption has not been well tested, because so far e i cannot be measured directly. Here, we test this assumption using a novel technique, based on coupled measurements of leaf gas exchange and the stable isotopemore » compositions of CO 2 and water vapour passing over the leaf. We applied this technique to mature individuals of two semiarid conifer species. In both species, e i routinely dropped below saturation when leaves were exposed to moderate to high air vapour pressure deficits. Typical values of relative humidity in the intercellular air spaces were as low 0.9 in Juniperus monosperma and 0.8 in Pinus edulis. These departures of e i from saturation caused significant biases in calculations of g s and the intercellular CO 2 concentration. Thus, our results refute the longstanding assumption of saturated vapour pressure in plant leaves under all conditions.« less

Gas in scattering media absorption spectroscopy - GASMAS

NASA Astrophysics Data System (ADS)

Svanberg, Sune

2008-09-01

An overview of the new field of Gas in Scattering Media Absorption Spectroscopy (GASMAS) is presented. GASMAS combines narrow-band diode-laser spectroscopy with diffuse media optical propagation. While solids and liquids have broad absorption features, free gas in pores and cavities in the material is characterized by sharp spectral signatures, typically 10,000 times sharper than those of the host material. Many applications in materials science, food packaging, pharmaceutics and medicine have been demonstrated. So far molecular oxygen and water vapour have been studied around 760 and 935 nm, respectively. Liquid water, an important constituent in many natural materials, such as tissue, has a low absorption at such wavelengths, allowing propagation. Polystyrene foam, wood, fruits, food-stuffs, pharmaceutical tablets, and human sinus cavities have been studied. Transport of gas in porous media can readily be studied by first immersing the material in, e.g., pure nitrogen, and then observing the rate at which normal air, containing oxygen, reinvades the material. The conductance of the sinus connective passages can be measured in this way by flushing the nasal cavity with nitrogen. Also other dynamic processes such as drying of materials can be studied. The techniques have also been extended to remote-sensing applications (LIDAR-GASMAS).

Application of Cryocoolers to a Vintage Dilution Refrigerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmitt, Richard; Smith, Gary; Ruschman, Mark

2011-06-06

A dilution refrigerator is required for 50mK detector operation of CDMS (Cryogenic Dark Matter Search). Besides shielding the dilution refrigerator itself, the liquid nitrogen shield and liquid helium bath in the refrigerator cool the detector cryostat heat shields and cool electronics, resulting in significant external heat loads at 80K and at 4K. An Oxford Instruments Kelvinox 400 has served this role for ten years but required daily transfers of liquid nitrogen and liquid helium. Complicating the cryogen supply is the location 800 meters below ground in an RF shielded, class 10000 clean room at Soudan, MN. Nitrogen and helium re-liquefiersmore » using cryocoolers were installed outside the clean room and continuously condense room temperature gas and return the liquids to the dilution refrigerator through a transfer line. This paper will describe the design, installation, controls and performance of liquefaction systems.« less

46 CFR 58.20-15 - Installation of refrigerating machinery.

Code of Federal Regulations, 2011 CFR

2011-10-01

... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Refrigeration Machinery § 58.20-15 Installation of... refrigeration compressor spaces shall be effectively ventilated and drained and shall be separated from the...

46 CFR 58.20-15 - Installation of refrigerating machinery.

Code of Federal Regulations, 2012 CFR

2012-10-01

... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Refrigeration Machinery § 58.20-15 Installation of... refrigeration compressor spaces shall be effectively ventilated and drained and shall be separated from the...

46 CFR 58.20-15 - Installation of refrigerating machinery.

Code of Federal Regulations, 2010 CFR

2010-10-01

... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Refrigeration Machinery § 58.20-15 Installation of... refrigeration compressor spaces shall be effectively ventilated and drained and shall be separated from the...

46 CFR 58.20-15 - Installation of refrigerating machinery.

Code of Federal Regulations, 2013 CFR

2013-10-01

... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Refrigeration Machinery § 58.20-15 Installation of... refrigeration compressor spaces shall be effectively ventilated and drained and shall be separated from the...

46 CFR 58.20-15 - Installation of refrigerating machinery.

Code of Federal Regulations, 2014 CFR

2014-10-01

... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Refrigeration Machinery § 58.20-15 Installation of... refrigeration compressor spaces shall be effectively ventilated and drained and shall be separated from the...

Crohn's Disease and Early Exposure to Domestic Refrigeration

PubMed Central

Malekzadeh, Fatemeh; Alberti, Corinne; Nouraei, Mehdi; Vahedi, Homayoon; Zaccaria, Isabelle; Meinzer, Ulrich; Nasseri-Moghaddam, Siavosh; Sotoudehmanesh, Rasoul; Momenzadeh, Sara; Khaleghnejad, Reza; Rashtak, Shahrooz; Olfati, Golrokh; Malekzadeh, Reza; Hugot, Jean-Pierre

2009-01-01

Background Environmental risk factors playing a causative role in Crohn's Disease (CD) remain largely unknown. Recently, it has been suggested that refrigerated food could be involved in disease development. We thus conducted a pilot case control study to explore the association of CD with the exposure to domestic refrigeration in childhood. Methodology/Principal Findings Using a standard questionnaire we interviewed 199 CD cases and 207 age-matched patients with irritable bowel syndrome (IBS) as controls. Cases and controls were followed by the same gastroenterologists of tertiary referral clinics in Tehran, Iran. The questionnaire focused on the date of the first acquisition of home refrigerator and freezer. Data were analysed by a multivariate logistic model. The current age was in average 34 years in CD cases and the percentage of females in the case and control groups were respectively 48.3% and 63.7%. Patients were exposed earlier than controls to the refrigerator (X2 = 9.9, df = 3, P = 0.04) and refrigerator exposure at birth was found to be a risk factor for CD (OR = 2.08 (95% CI: 1.01–4.29), P = 0.05). Comparable results were obtained looking for the exposure to freezer at home. Finally, among the other recorded items reflecting the hygiene and comfort at home, we also found personal television, car and washing machine associated with CD. Conclusion This study supports the opinion that CD is associated with exposure to domestic refrigeration, among other household factors, during childhood. PMID:19177167

Water vapour and methane coupling in the stratosphere observed using SCIAMACHY solar occultation measurements

NASA Astrophysics Data System (ADS)

Noël, Stefan; Weigel, Katja; Bramstedt, Klaus; Rozanov, Alexei; Weber, Mark; Bovensmann, Heinrich; Burrows, John P.

2018-04-01

An improved stratospheric water vapour data set has been retrieved from SCIAMACHY/ENVISAT solar occultation measurements. It is similar to that successfully applied to methane and carbon dioxide. There is now a consistent set of data products for the three constituents covering the altitudes 17-45 km, the latitude range between about 50 and 70° N, and the period August 2002 to April 2012. The new water vapour concentration profiles agree with collocated results from ACE-FTS and MLS/Aura to within ˜ 5 %. A significant positive linear change in water vapour for the time 2003-2011 is observed at lower stratospheric altitudes with a value of about 0.015 ± 0.008 ppmv year-1 around 17 km. Between 30 and 37 km the changes become significantly negative (about -0.01 ± 0.008 ppmv year-1); all errors are 2σ values. The combined analysis of the SCIAMACHY methane and water vapour time series shows the expected anti-correlation between stratospheric methane and water vapour and a clear temporal variation related to the Quasi-Biennial Oscillation (QBO). Above about 20 km most of the additional water vapour is attributed to the oxidation of methane. In addition short-term fluctuations and longer-term variations on a timescale of 5-6 years are observed. The SCIAMACHY data confirm that at lower altitudes the amount of water vapour and methane are transported from the tropics to higher latitudes via the shallow branch of the Brewer-Dobson circulation.

The Refrigeration System; Appliance Repair--Advanced: 9027.01.

ERIC Educational Resources Information Center

Dade County Public Schools, Miami, FL.

This course outline provides students with an understanding of the observation of basic refrigeration system components, the techniques used in working with copper tubing, and practice demonstrations to show what they have learned. Course content includes specific block objectives, orientation, refrigeration components (evaporator, compressor,…

40 CFR 82.36 - Approved refrigerant handling equipment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Approved refrigerant handling equipment. (a)(1) Refrigerant recycling equipment must be certified by the...) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning Systems. (5... Recycling Equipment Intended for Use with both CFC-12 and HFC-134a, Recommended Service Procedure for the...

40 CFR 82.36 - Approved refrigerant handling equipment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Approved refrigerant handling equipment. (a)(1) Refrigerant recycling equipment must be certified by the...) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning Systems. (5... Recycling Equipment Intended for Use with both CFC-12 and HFC-134a, Recommended Service Procedure for the...

40 CFR 82.36 - Approved refrigerant handling equipment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Approved refrigerant handling equipment. (a)(1) Refrigerant recycling equipment must be certified by the...) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning Systems. (5... Recycling Equipment Intended for Use with both CFC-12 and HFC-134a, Recommended Service Procedure for the...

40 CFR 82.36 - Approved refrigerant handling equipment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Approved refrigerant handling equipment. (a)(1) Refrigerant recycling equipment must be certified by the...) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning Systems. (5... Recycling Equipment Intended for Use with both CFC-12 and HFC-134a, Recommended Service Procedure for the...

40 CFR 82.36 - Approved refrigerant handling equipment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Approved refrigerant handling equipment. (a)(1) Refrigerant recycling equipment must be certified by the...) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning Systems. (5... Recycling Equipment Intended for Use with both CFC-12 and HFC-134a, Recommended Service Procedure for the...

An experimental investigation of ejector performance based upon different refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, S.L.; Yen, J.Y.; Huang, M.C.

1998-12-31

This article experimentally compares the characteristics of different refrigerants as the working fluid in an ejector cooling system. The study covers common refrigerants including R-113, R-114, R-142b, and R-718. The critical choking conditions against the variation of condenser back pressure, the evaporator pressure, and the generator pressure are determined for each refrigerant. The results are compiled into a convenient performance curve and COP chart. These results can serve as an important reference for future design of ejector cooling systems. Finally, this paper presents a comparison of the performances of different refrigerants in an ejector cooling system.

Compact acoustic refrigerator

DOEpatents

Bennett, Gloria A.

1992-01-01

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

Gas-fired duplex free-piston Stirling refrigerator

NASA Astrophysics Data System (ADS)

Urieli, L.

1984-03-01

The duplex free-piston Stirling refrigerator is a potentially high efficiency, high reliability device which is ideally suited to the home appliance field, in particular as a gas-fired refrigerator. It has significant advantages over other equivalent devices including freedom from halogenated hydrocarbons, extremely low temperatures available at a high efficiency, integrated water heating, and simple burner system control. The design and development of a portable working demonstration gas-fired duplex Stirling refrigeration unit is described. A unique combination of computer aided development and experimental development was used, enabling a continued interaction between the theoretical analysis and practical testing and evaluation. A universal test rig was developed in order to separately test and evaluate major subunits, enabling a smooth system integration phase.

Solubility modeling of refrigerant/lubricant mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michels, H.H.; Sienel, T.H.

1996-12-31

A general model for predicting the solubility properties of refrigerant/lubricant mixtures has been developed based on applicable theory for the excess Gibbs energy of non-ideal solutions. In our approach, flexible thermodynamic forms are chosen to describe the properties of both the gas and liquid phases of refrigerant/lubricant mixtures. After an extensive study of models for describing non-ideal liquid effects, the Wohl-suffix equations, which have been extensively utilized in the analysis of hydrocarbon mixtures, have been developed into a general form applicable to mixtures where one component is a POE lubricant. In the present study we have analyzed several POEs wheremore » structural and thermophysical property data were available. Data were also collected from several sources on the solubility of refrigerant/lubricant binary pairs. We have developed a computer code (NISC), based on the Wohl model, that predicts dew point or bubble point conditions over a wide range of composition and temperature. Our present analysis covers mixtures containing up to three refrigerant molecules and one lubricant. The present code can be used to analyze the properties of R-410a and R-407c in mixtures with a POE lubricant. Comparisons with other models, such as the Wilson or modified Wilson equations, indicate that the Wohl-suffix equations yield more reliable predictions for HFC/POE mixtures.« less

A sensor of alcohol vapours based on thin polyaniline base film and quartz crystal microbalance.

PubMed

Ayad, Mohamad M; El-Hefnawey, Gad; Torad, Nagy L

2009-08-30

Thin films of polyaniline base, emeraldine base (EB), coating on the quartz crystal microbalance (QCM) electrode were used as a sensitive layer for the detection of a number of primary aliphatic alcohols such as ethanol, methanol, 2-propanol and 1-propanol vapours. The frequency shifts (Deltaf) of the QCM were increased due to the vapour adsorption into the EB film. Deltaf were found to be linearly correlated with the concentrations of alcohols vapour in part per million (ppm). The sensitivity of the sensor was found to be governed by the chemical structure of the alcohol. The sensor shows a good reproducibility and reversibility. The diffusions of different alcohols vapour were studied and the diffusion coefficients (D) were calculated. It is concluded that the diffusion of the vapours into the EB film follows Fickian kinetics.

Retail Food Refrigeration and the Phaseout of HCFC-22

EPA Pesticide Factsheets

Provides information on the HCFC phaseout that is relevant to food retailers, including alternatives to the use of HCFC-22 in retail food refrigeration, other refrigerant regulations, and resources for more information.

R-134a qualification -- industry refrigerator capillary data

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeVos, R.

1997-12-31

With the phaseout of R-12, the use of R-134a and polyolester (POE) oil became the preferred refrigerant/oil combination for the refrigerator appliance industry. Reliability data for this refrigerant/oil combination were minimal, and initial testing showed a propensity for the capillary tubes to clog with a variety of contaminants. A test was designed by an industry group to accelerate the process of contamination and capillary plugging. This paper presents capillary tube stress test data that were developed for this group by its member companies. This study investigated the relationship between capillary tube restriction levels and variables including compressor type, oil type,more » chlorine level, and moisture level. Analysis of the contaminants included a visual description, infrared spectroscopy, scanning electron microscope examination, and measurements of total chlorine content and noncondensable gas content of the refrigerant. Oil samples were measured for moisture level, dissolved iron, and total acid, and an infrared spectral analysis was performed.« less

Analysis of household refrigerators for different testing standards

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, P.K.; McGill, I.

This study highlights the salient differences among various testing standards for household refrigerator-freezers and proposes a methodology for predicting the performance of a single evaporator-based vapor-compression refrigeration system (either refrigerator or freezer) from one test standard (where the test data are available-the reference case) to another (the alternative case). The standards studied during this investigation include the Australian-New Zealand Standard (ANZS), the International Standard (ISO), the American National Standard (ANSI), the Japanese Industrial Standard (JIS), and the Chinese National Standard (CNS). A simple analysis in conjunction with the BICYCLE model (Bansal and Rice 1993) is used to calculate the energymore » consumption of two refrigerator cabinets from the reference case to the alternative cases. The proposed analysis includes the effect of door openings (as required by the JIS) as well as defrost heaters. The analytical results are found to agree reasonably well with the experimental observations for translating energy consumption information from one standard to another.« less

Air Conditioning and Refrigeration Program Articulation, 1981-1982.

ERIC Educational Resources Information Center

Dallas County Community Coll. District, TX.

Based on a survey of high school programs and courses in the Dallas County Community College District (DCCCD), this articulated program is designed to prepare students for entry-level employment in the air conditioning and refrigeration industry, including residential and commercial air conditioning and commercial refrigeration. The skills and…

Effect of Refrigeration on Inoculated Micro-ID Strips

PubMed Central

Burdash, Nicholas M.; West, Marcia E.

1981-01-01

Since reading results after 4 h with the Micro-ID system is not always convenient, a study of 500 isolates indicated that identification at the species level is essentially unchanged when inoculated strips are refrigerated overnight and then incubated or incubated and then refrigerated overnight before reading. PMID:7026604

Refrigeration and Cryogenics Specialist. J3ABR54530

ERIC Educational Resources Information Center

Air Force Training Command, Sheppard AFB, TX.

This document package contains an Air Force course used to train refrigeration and cryogenics specialists. The course is organized in six blocks designed for group instruction. The blocks cover the following topics: electrical principles; fundamentals of tubing and piping; metering devices, motor controls, domestic and commercial refrigeration;…

Analysis of Environmentally Friendly Refrigerant Options for Window Air Conditioners

DOE PAGES

Bansal, Pradeep; Shen, Bo

2015-03-12

This paper presents a technical assessment of environmentally friendly refrigerants as alternatives to R410A for window air conditioners. The alternative refrigerants that are studied for its replacement include R32, a mixture of R32/R125 with 90%/10% molar concentration, R600a, R290, R1234yf, R1234ze and R134a. Baseline experiments were performed on a window unit charged with R410A. The heat pump design model (HPDM) was modified and calibrated with the baseline data and was used to evaluate the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and their suitability for window air conditioners. Amongmore » all the refrigerants studied, R32 offers the best efficiency and the lowest Global Warming Potential (GWP), and hence its use will result in the overall environmental friendliness.« less

Technology Application of Environmental Friendly Refrigeration (Green Refrigeration) on Cold Storage for Fishery Industry

NASA Astrophysics Data System (ADS)

Rasta, IM; Susila, IDM; Subagia, IWA

2018-01-01

The application of refrigeration technology to postharvest fishery products is an very important. Moreover, Indonesia is a tropical region with relatively high temperatures. Fish storage age can be prolonged with a decrease in temperature. Frozen fish can even be stored for several months. Fish freezing means preparing fish for storage in low-temperature cold storage. The working fluid used in cold storage to cool low-temperature chambers and throw heat into high-temperature environments is refrigerant. So far refrigerant used in cold storage is Hydrochloroflourocarbons (HCFC) that is R-22. Chlor is a gas that causes ODP (Ozone Depleting Potential), while Flour is a gas that causes GWP (Global Warming Potential). Government policy began in 2015 to implement Hydrochloroflourocarbons Phase-Out Management Plan. Hydrocarbon (HC) is an alternative substitute for R-22. HC-22 (propane ≥ 99.5%) has several advantages, among others: environmentally friendly, indicated by a zero ODP value, and GWP = 3 (negligible), thermophysical property and good heat transfer characteristics, vapor phase density Which is low, and good solubility with mineral lubricants. The use of HC-22 in cold storage is less than R-22. From the analysis results obtained, cold storage system using HC-22 has better performance and energy consumption is more efficient than the R-22.

21 CFR 864.9700 - Blood storage refrigerator and blood storage freezer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Blood storage refrigerator and blood storage... Establishments That Manufacture Blood and Blood Products § 864.9700 Blood storage refrigerator and blood storage freezer. (a) Identification. A blood storage refrigerator and a blood storage freezer are devices intended...

21 CFR 864.9700 - Blood storage refrigerator and blood storage freezer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Blood storage refrigerator and blood storage... Establishments That Manufacture Blood and Blood Products § 864.9700 Blood storage refrigerator and blood storage freezer. (a) Identification. A blood storage refrigerator and a blood storage freezer are devices intended...

21 CFR 864.9700 - Blood storage refrigerator and blood storage freezer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Blood storage refrigerator and blood storage... Establishments That Manufacture Blood and Blood Products § 864.9700 Blood storage refrigerator and blood storage freezer. (a) Identification. A blood storage refrigerator and a blood storage freezer are devices intended...

21 CFR 864.9700 - Blood storage refrigerator and blood storage freezer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Blood storage refrigerator and blood storage... Establishments That Manufacture Blood and Blood Products § 864.9700 Blood storage refrigerator and blood storage freezer. (a) Identification. A blood storage refrigerator and a blood storage freezer are devices intended...

21 CFR 864.9700 - Blood storage refrigerator and blood storage freezer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood storage refrigerator and blood storage... Establishments That Manufacture Blood and Blood Products § 864.9700 Blood storage refrigerator and blood storage freezer. (a) Identification. A blood storage refrigerator and a blood storage freezer are devices intended...

Refrigeration, Heating & Air Conditioning. Post Secondary Curriculum Guide.

ERIC Educational Resources Information Center

Garrison, Joe C.; And Others

This curriculum guide was designed for use in postsecondary refrigeration, heating and air conditioning education programs in Georgia. Its purpose is to provide for the development of entry level skills in refrigeration, heating, and air conditioning in the areas of air conditioning knowledge, theoretical structure, tool usage, diagnostic ability,…

Elastohydrodynamic Lubrication with Polyolester Lubricants and HFC Refrigerants, Final Report, Volume 2