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1

TWO-PHASE FLOW OF TWO HFC REFRIGERANT MIXTURES THROUGH SHORT-TUBE ORIFICES  

EPA Science Inventory

The report gives results of an experimental investigation to develop an acceptable flow model for short tube orifice expansion devices used in heat pumps. The refrigerants investigated were two hydrofluorocarbon (HFC) mixtures considered hydrochlorofluorocarbon (HCFC)-22 replacem...

2

The surface tension of HFC refrigerants and mixtures  

Microsoft Academic Search

The surface tension of the refrigerants R32, R125, R134a, R143a and R152a, as well as the binary refrigerant mixtures R32-R125, R32-R134a, R125-R134a, R125-R143a, R125- R152a, R143a-R134a and R134a-R152a, and the commercially available ternary mixtures R404A and R407C was measured across the temperature range from ?50 to 60°C using a measuring unit based on the capillary rise method. Different formulations for

R Heide

1997-01-01

3

The Performance Evaluation of Vapor Compression Heat Pump System Using HFC Alternative Refrigerant Mixtures  

NASA Astrophysics Data System (ADS)

This paper deals with an experimental study on the performance evaluation of heat pump systems using HFC alternative refrigerants. The tested heat pump systems are modified from the R22 use to alternative refrigerants. Refrigerant mixtures of R410A, R407C. R32/125 and R32/134a are tested. where R410A and R407C launched into global market recently. Pure refrigerants of R22, R32, R125 and R134a are also tested. The experimental results of alternative refrigerants are evaluated in comparison with the result of R22, and the following are confirmed : (1) the performance of R32 is the highest. (2) adding R125 to R32 and R32/134a results into the deterioration of the performance, (3) the use of counter flow-like heat exchangers for a zeotropic refrigerant mixtures are effective, and (4) in case of R410A. the modification of the compressor to fit operating pressure heightens the performance. The effects of the performance of components on the COP are also analyzed based on the measured thermodynamic states at both ends of components in the system. Then, it is clarified that the most effective factor is irreversibility of compressors and the following is the pressure drop in low pressure side including the evaporator and the suction pipe.

Taira, Shigeharu; Yazima, Ryuzaburo; Tarutani, Isamu; Koyama, Shigeru

4

Two-Phase Flow of Two HFC Refrigerant Mixtures Through Short Tube Orifices, Draft Final Report  

E-print Network

The present study presents data for flow of two refrigerant mixtures through short tube orifices. The two mixtures were R3211251134a (23%/25%/52% on a mass percentage basis) and R321125 (50%/50%). The following presents results for the flow...

Payne, W. V.; O'Neal, D. L.

1994-01-01

5

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...

6

Thermal conductivity of binary refrigerant mixtures of HFC-32/125 and HFC-32/134a in the liquid phase  

SciTech Connect

The liquid thermal conductivity of mixtures of HFC-32/125 and HFC-32/134a was measured using the transient hot-wire apparatus in the temperature ranges from 213 to 293 K and from 193 to 313 K, respectively, in the pressure range from 2 to 30 MPa and with HFC-32 mass fractions of 0.249, 0.500, and 0.750 for each system. The uncertainty of the thermal conductivity was estimated to be {+-}0.7%. For practical applications, the thermal conductivity data for the two mixtures were represented by a polynomial in temperature, pressure, and mass fraction of HFC-32 with a standard deviation of 1.0%.

Gao, X.; Nagasaka, Y.; Nagashima, A.

1999-09-01

7

Thermal conductivity of ternary refrigerant mixtures of HFC-32/125/134a in the liquid phase  

SciTech Connect

The liquid thermal conductivity of two ternary mixtures of HFC-32/125/134a (23.0/25.0/52.0 and 19.0/43.8/37.2 wt%) was measured using a transient hotwire instrument in the temperature ranges from 193 to 293 K and from 213 to 293, respectively, and in the pressure range from 2 to 30 MPa. The thermal conductivity has an estimated uncertainty of {+-}7.0%. For engineering purposes, the thermal conductivity data were correlated using a polynomial in temperature and pressure for each mixture with a standard deviation of 0.6%.

Gao, X.; Nagasaka, Y.; Nagashima, A.

1999-09-01

8

Viscosities of HFC-32 and HFC-32/lubricant mixtures  

SciTech Connect

A modified capillary tube method has been used to measure viscosities for HFC-32 over a temperature range from {minus}20 to 90{degrees}C and a pressure range from 0.1 to 5.3 MPa, and for the liquid mixtures of HFC-32 with a synthetic polyolester oil at temperatures from 20 to 75{degrees}C and oil mass fractions from 0.44 to 1. Estimated uncertainties in the measured viscosities do not exceed {plus_minus}1.2 and {plus_minus}1.8% for the pure fluorocarbon and the mixtures, respectively. It is found that viscosity isotherms for HFC-32 at subcritical temperatures exhibit a minimum with increasing pressure, with the viscosity decreasing as much as 10% relative to its value at one atmosphere. Correlations are presented for dilute gas viscosities, excess viscosities, and saturated liquid and vapor viscosities. These correlations are shown to fit this data within experimental uncertainties. For HFC-32/lubricant mixtures, a free-volume viscosity model has been applied to correlate the experimental data.

Geller, V.Z. [Thermophysics Research Center, San Francisco, CA (United States); Paulaitis, M.E. [Univ. of Delaware, Newark, DE (United States); Bivens, D.B. [E.I. du Pont Nemours and Co., Wilmington, DE (United States)

1996-01-01

9

Ozone friendly HFC134a\\/HC mixture compatible with mineral oil in refrigeration system improves energy efficiency of a walk in cooler  

Microsoft Academic Search

In the event of chlorofluorocarbon (CFC) phase out, identifying a long term alternative to meet all our requirements in respect of system performance and service is an important area for research in the refrigeration and air conditioning (RAC) sector. Even though HFC134a and the HC blend (containing 55.2% HC600a and 44.8% HC290) have been reported to be substitutes for CFC12,

S. Joseph Sekhar; K. Senthil Kumar; D. Mohan Lal

2004-01-01

10

PERFORMANCE OF CHLORINE-FREE BINARY ZEOTROPIC REFRIGERANT MIXTURES IN A HEAT PUMP  

EPA Science Inventory

The report gives results of a study that uses a simulation model and an experimental heat pump apparatus with counterflow heat exchangers to show that two hydrofluorocarbon (HFC) refrigerant mixtures, HFC-32/-152a and HFC-32/-134a, may be considered to be replacements for hydroch...

11

Dynamic Viscosity for HFC-134a + Polyether mixtures up to 373.15 K and 140 MPa at low polyether concentration. Measurements and Modelling.  

E-print Network

1 Dynamic Viscosity for HFC-134a + Polyether mixtures up to 373.15 K and 140 MPa at low polyether: This paper reports viscosity data for mixtures containing a refrigerant (HFC-134a) and a lubricant. A specially designed isobaric transfer falling-body viscometer is used in this work. The viscosity

Paris-Sud XI, Université de

12

Cycle performance testing of nonazeotropic mixtures of HFC-142A/HCFC-124 and HFC-32/HCFC-124 with enhanced surface heat exchangers  

NASA Astrophysics Data System (ADS)

In an effort to improve the efficiency of residential heat pumps using alternative refrigerants, two nonazeotropic refrigerant mixtures (NARM's) were tested over a range of heat exchanger capacities to determine their cooling mode performance at US Department of Energy (DOE) heat pump rating conditions of 82 F (27.8 C). The two mixtures, 30% HFC-32/70% HCFC-124 and 75% HFC-143a/25% HCFC-124, were selected on the basis of a previous study that screened refrigerant pairs using such factors as boiling point, stability, ozone depletion potential (ODP), and coefficient of performance (COP) to determine suitable candidates for residential heat pump performance. Three refrigerant-side heat transfer enhancements were tested to determine improvements to overall system performance. Comparisons were made on the basis of the COP as a function of capacity. The results for one of the heat exchanger combinations, a segmented evaporator and finned condenser, were quite promising. Improvements in COP, relative to that for HCFC-22, were from 9 to 17% for the 30% HFC-32/70% HCFC-124 mixture and from 5 to 9% for the 75% HFC-143a/25% HCFC-124 NARM. Another combination, a smooth tube evaporator with a perforated foil insert and finned condenser, had similar gains at low capacities but experienced decreased performance at the higher capacities. The final combination, a smooth tube evaporator with a perforated foil insert and smooth tube condenser with a bent tab insert resulted in poor performance.

Vineyard, E. A.; Conklin, J. C.; Brown, A. J.

13

Simulation of vapor-compression refrigeration cycles using HFC134a and CFC12  

Microsoft Academic Search

A performance comparison analysis of vapor-compression refrigeration systems using refrigerant HFC134a and CFC12 is presented. The analysis is based on computer simulation of actual cycles rather than the ideal cycles. The simulation models for HFC134a and CFC12 are developed on the basis of fluid properties and thermo-hydraulic characteristics obtained from available experimental data and\\/or correlations. Using the simulation model thus

Q. Chen; R. C. Prasad

1999-01-01

14

Determination of properties of PVE lubricants with HFC refrigerants[PolyVinylEther  

SciTech Connect

Polyalkyleneglycol (PAG) and polyol ester (POE) have been developed as refrigeration lubricants, used with HFC134a. PAG is used for automotive air conditioning systems and POE is used for domestic reciprocating refrigerators and for A/C systems. Although PAG exhibits good lubricity performance, it is difficult to use for domestic reciprocating refrigerators due to its low dielectric property. POE is difficult to use for automotive A/C systems, due to hydrolysis and poor lubricity performance. Polyvinylether (PVE) can be used in place of PAG and POE with HFC refrigerants. PVE is used for A/C systems as well as refrigerator and freezer applications. PVE is an ideal lubricant for use with HFCs.

Kaneko, Masato; Sakanoue, Shuichi; Tazaki, Toshihiro; Tominaga, Shoichi; Takagi, Minoru; Goodin, M.

1999-07-01

15

MODELING AND DESIGN STUDY USING HFC-236EA AS AN ALTERNATIVE REFRIGERANT IN A CENTRIFUGAL COMPRESSOR  

EPA Science Inventory

The report gives results of an investigation of the operation of a centrifugal compressor--part of a chlorofluorocarbon (CFC)-114 chiller installation--with the new refrigerant hydrofluorocarbon (HFC)-236ea, a proposed alternative to CFC-114. A large set of CFC-236ea operating da...

16

Global emissions of refrigerants HCFC-22 and HFC-134a: Unforeseen seasonal contributions.  

PubMed

HCFC-22 (CHClF2) and HFC-134a (CH2FCF3) are two major gases currently used worldwide in domestic and commercial refrigeration and air conditioning. HCFC-22 contributes to stratospheric ozone depletion, and both species are potent greenhouse gases. In this work, we study in situ observations of HCFC-22 and HFC-134a taken from research aircraft over the Pacific Ocean in a 3-y span [HIaper-Pole-to-Pole Observations (HIPPO) 2009-2011] and combine these data with long-term ground observations from global surface sites [National Oceanic and Atmospheric Administration (NOAA) and Advanced Global Atmospheric Gases Experiment (AGAGE) networks]. We find the global annual emissions of HCFC-22 and HFC-134a have increased substantially over the past two decades. Emissions of HFC-134a are consistently higher compared with the United Nations Framework Convention on Climate Change (UNFCCC) inventory since 2000, by 60% more in recent years (2009-2012). Apart from these decadal emission constraints, we also quantify recent seasonal emission patterns showing that summertime emissions of HCFC-22 and HFC-134a are two to three times higher than wintertime emissions. This unforeseen large seasonal variation indicates that unaccounted mechanisms controlling refrigerant gas emissions are missing in the existing inventory estimates. Possible mechanisms enhancing refrigerant losses in summer are (i) higher vapor pressure in the sealed compartment of the system at summer high temperatures and (ii) more frequent use and service of refrigerators and air conditioners in summer months. Our results suggest that engineering (e.g., better temperature/vibration-resistant system sealing and new system design of more compact/efficient components) and regulatory (e.g., reinforcing system service regulations) steps to improve containment of these gases from working devices could effectively reduce their release to the atmosphere. PMID:25422438

Xiang, Bin; Patra, Prabir K; Montzka, Stephen A; Miller, Scot M; Elkins, James W; Moore, Fred L; Atlas, Elliot L; Miller, Ben R; Weiss, Ray F; Prinn, Ronald G; Wofsy, Steven C

2014-12-01

17

Study on the Interaction Coefficients in PR Equation with vdW Mixing Rules for HFC and HC Binary Mixtures  

NASA Astrophysics Data System (ADS)

The Peng-Robinson equation of state with the van der Waals mixing rules was used to correlate vapor-liquid equilibrium (VLE) data for HFC/HC, HFC/HFC, and HC/HC binary mixtures. The interaction parameter k ij was obtained for every binary mixture. It was assumed that k ij has contributions from the two components, and each component has its own constant contribution factor k i for the mixture, and the values of k ij indicate the degree in difference of properties between the two components. Therefore, the interaction parameters k ij is proposed as: k ij = k i - k j . The values of the mixing factor k i for Hydrofluorocarbons (HFCs) and Hydrocarbons (HCs), including propane, isobutane, n-butane, R23, R32, R125, R143a, R134a, R152a, R227ea R236fa, R236ea, and R245fa, were obtained by least-square fitting. In total, 39 refrigerant binary mixtures were analyzed on the basis of this method, and the results showed good agreement with experimental data. The overall average absolute deviations of pressure and vapor mole fraction are 1.3 % and 0.0089, respectively.

Chen, Jian-Xin; Hu, Peng; Chen, Ze-Shao

2008-12-01

18

Evaluation of ozone-friendly hydrofluoropropane-based zeotropic refrigerant mixtures in a Lorenz-Meutzner refrigerator/freezer  

SciTech Connect

In this study, the L-M R/F having two evaporators and two intercoolers was experimentally tested in an environmental chamber according to Association of Home Appliance Manufacturers/Department of Energy testing standards using several hydrofluoropropane-based zeotropic mixtures. The results are compared to baseline testing with HFC-134a. A refrigerant sampling loop was added to determine the running composition of the mixture and its effect on the R/F performance.

Baskin, E.; Bayoglu, E.; Delafield, F.R.

1995-01-01

19

Evaluation of ozone-friendly hydrofluoropropane-based zeotropic refrigerant mixtures in a Lorenz-Meutzner refrigerator\\/freezer  

Microsoft Academic Search

In this study, the L-M R\\/F having two evaporators and two intercoolers was experimentally tested in an environmental chamber according to Association of Home Appliance Manufacturers\\/Department of Energy testing standards using several hydrofluoropropane-based zeotropic mixtures. The results are compared to baseline testing with HFC-134a. A refrigerant sampling loop was added to determine the running composition of the mixture and its

E. Baskin; E. Bayoglu; F. R. Delafield

1995-01-01

20

Miscibility comparison for three refrigerant mixtures and four component refrigerants  

SciTech Connect

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 miscibility 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.

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

1999-07-01

21

Solubility, viscosity and density of refrigerant/lubricant mixtures  

SciTech Connect

This report presents results on low refrigerant concentration (70, 80, 90, and 100 weight percent lubricant) mixtures of the following fluids: CFC-12/ISO 32 naphthenic mineral oil; HCFC-22/ISO 32 naphthenic mineral oil; and HFC-134a/ISO 32 pentaerythritol ester mixed acid. These data have been reduced to engineering form and are presented in the form of a Daniel Chart. Scatter diagrams are given for the first fluid listed above, with the intent of illustrating the quality of data as well as providing the rationale for selecting the particular functional forms chosen to represent the experimental data. Equations are given along with statistical measures of goodness of fit.

Henderson, D.R.

1993-01-01

22

Performance of a two-cycle refrigerator/freezer using HFC refrigerants  

SciTech Connect

A two-cycle 18 ft{sup 3} (0.51 m{sup 3}) refrigerator/freezer was tested utilizing American National Standards Institute/Association of Home Appliance Manufacturers (ANSI/AHAM) standards for energy consumption testing. A 34.9% energy consumption reduction was realized for a 1984 model refrigerator/freezer (1020 kWh original energy use). This paper presents a proven method of reducing the current Department of Energy (DOE) minimum energy-efficiency standards for refrigerator/freezers to the proposed year 2001 standards utilizing existing technology. For a top-mount, frost-free refrigerator/freezer having the above volume, the current DOE minimum energy standard is 770 kWh/year, and the proposed DOE year 2001 standard is 530 kWh/year (a 31% reduction). Therefore, some significant reductions may be obtained by implementing the modifications discussed in this paper into newer refrigerator/freezer models. The paper gives an overview of the modifications implemented by a Danish university on a US refrigerator/freezer and presents experimental performance testing results of the refrigerator/freezer. The modifications will cause the refrigerator/freezer to be more expensive, but the performance enhancements should offset cost. No cost analysis is presented in this paper, but a detailed cost analysis of a two-cycle refrigerator/freezer is contained in a 1993 US Environmental Protection Agency (EPA) report (EPA 1993). The refrigerator/freezer was tested using four refrigerants and compressors. Two compressors and refrigerants were tested in the freezer cycle, and four were tested in the fresh food cycle.

Baskin, E.; Delafield, F.R.

1999-07-01

23

Elastohydrodynamic Lubrication with Polyolester Lubricants and HFC Refrigerants, Final Report, Volume 2  

SciTech Connect

Lubrication properties of refrigeration lubricants were investigated in high pressure nonconforming contacts under different conditions of temperature, rolling speed, and refrigerant concentration. The program was based upon the recognition that the lubrication regime in refrigeration compressors is generally elastohydrodynamic or hydrodynamic, as determined by the operating conditions of the compressor and the properties of the lubricant. Depending on the compressor design, elastohydrodynamic lubrication conditions exist in many rolling and sliding elements of refrigeration compressors such as roller element bearings, gears, and rotors. The formation of an elastohydrodynamic film separating rubbing surfaces is important in preventing the wear and failure of compressor elements. It is, therefore, important to predict the elastohydrodynamic (EHD) performance of lubricants under realistic tribocontact renditions. This is, however, difficult as the lubricant properties that control film formation are critically dependent upon pressure and shear, and cannot be evaluated using conventional laboratory instruments. In this study, the elastohydrodynamic behavior of refrigeration lubricants with and without the presence of refrigerants was investigated using the ultrathin film EHD interferometry technique. This technique enables very thin films, down to less than 5 nm, to be measured accurately within an EHD contact under realistic conditions of temperature, shear, and pressure. The technique was adapted to the study of lubricant refrigerant mixtures. Film thickness measurements were obtained on refrigeration lubricants as a function of speed, temperature, and refrigerant concentration. The effects of lubricant viscosity, temperature, rolling speed, and refrigerant concentration on EHD film formation were investigated. From the film thickness measurements, effective pressure-viscosity coefficients were calculated. The lubricants studied in this project included two naphthenic mineral oils (NMO), four polyolesters (POE), and two polyvinyl ether (PVE) fluids. These fluids represented viscosity grades of ISO 32 and ISO 68 and are shown in a table. Refrigerants studied included R-22, R-134a, and R-410A. Film thickness measurements were conducted at 23 C, 45 C, and 65 C with refrigerant concentrations ranging from zero to 60% by weight.

Gunsel, Selda; Pozebanchuk, Michael

1999-04-01

24

EVALUATION OF PERFORMANCE AND COMPOSITION SHIFT OF ZEOTROPIC MIXTURES IN A LORENZ-MEUTZNER REFRIGERATOR/FREEZER  

EPA Science Inventory

Results from previous testing of this refrigerator/freezer (R/F) using a 750 Btu/hr compressor and several zeotrophic mixtures revealed a performance enhancement up to 16 percent above that of HFC-134a. In the study presented in this paper, the Lorenz-Meutzner (LM) R/F equipped ...

25

Analysis of Capillary Tube Sludge in Refrigeration Circuit with HFC 134 a  

NASA Astrophysics Data System (ADS)

We conducted a continuous test with a refrigeration test circuit using HFC 134 a,and we made a study of the form and components of the sludge inside the capillary tube comparing different kinds of lubricant from this perspective. A rotary compressor was used for the test, and HAB oil, blended oil and ester oil were employed as the lubricants. The results showed that the capillary sludge consists mainly of a copper oxide which is caused by corrosion in the case of the HAB oil, and mainly a metal soap, a decomposition product and polymeric product of the lubricant, and zeolite in the case of the ester oil. In order to decrease the amount of these sludges, it is necessary, in the former case, to remove the remaining chlorine solvents and other impurities in the constituent parts of the refrigeration test circuit and, in the latter case, to develop a stabler lubricant and zeolite. In the case of the blended oil, we discovered that zeolite and ohter substances are deposited in the capillary tube over the course of time.

Nakayama, Yoshinori; Yamamoto, Thutomu; Takahashi, Yuuichi; Shimizu, Yasuhiko; Takizawa, Kikuo; Yamasita, Tsugito

26

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 ...

27

Development of New Refrigeration Circuit to Control Refrigerant Mixture Composition  

NASA Astrophysics Data System (ADS)

The use of refrigerant mixture is an important subject of heat-pump technology and its research and developments have been promoted all over the world. We have tried to apply mixed refrigerants to air-conditioners, and developed an unique technology for efficiently separating and varying the mixing ratio of the refrigerants inside the refrigeration circuit. The mixed fluorinated refrigerants of R22-R13B1 were adapted to increase the heating capacity. Effects of shapes of packings and diameters of column were examined by an experimental apparatus of rectifier only, and a small rectifier with new coiled packings was developed. In the new circuit, the bottom of the rectifier is connected with condenser and evaporator by lines in parallel with expansion device. In the rectifying mode, the lower boiling-point refrigerant is stored in a reservoir connected to the top of the rectifier, and a main circuit is operated with the higher boiling-point refrigerant. Then the heating capacity, the input wattage and the fluid pressure of a heat-pump operating with the separated refrigerants are decreased to a lower level and its energy efficiency was improved through an inspection of the rectifying vapour generation method. The technique of estimating the composition of mixture operating in the circuit was developed, too, and the calculated values almost coincide with the experimetal values.

Yoshida, Yuji; Suzuki, Sigeo; Nakatani, Kazuo; Mukai, Yuji; Adachi, Masaaki

28

Heat exchanger analysis for nonazeotropic refrigerant mixtures  

SciTech Connect

A fundamental method for analyzing heat exchangers using pure refrigerants and nonazeotropic refrigerant mixtures is presented. The method allows for calculation of heat and mass transfer between moist air and nonazeotropic refrigerant mixtures and predicts local parameters of air and mixtures. Both single and two phase refrigerants can be analyzed with this method. Algorithms for the use of this model are presented. Data and calculated thermal performance for two conventional types of air-side geometries are also presented. The algorithms to calculate thermal performance of heat exchangers can be used for either conventional or enhanced geometries. A comparison of crossflow, cross-counterflow, and counterflow heat exchangers is given. The algorithms are sufficient for design and development of equipment using pure and mixed refrigerants.

Poz, M.Y. [Russian Association of Engineers for Heating, Ventilation, Air Conditioning, Heat Supply and Building Thermal Physics (ABOK), Moscow (Russian Federation); Conklin, J.C. [Oak Ridge National Lab., TN (United States)

1994-02-01

29

Chemical and thermal stability of refrigerant-lubricant mixtures with metals  

SciTech Connect

This report presents completed sealed tube stability test results for the following eight refrigerant/lubricant mixtures: R-22/mineral oil; R-124/alkylbenzene; R-134a/pentaerythritol (PE) ester (mixed acid); R- 134a/PE (branched acid); R-134a/ PE (100 cSt viscosity); R- 142b/alkylbenzene; R-143a/ PE (branched acid); R-152a/alkylbenzene. Partial results are shown for an additional eight refrigerant-lubricant mixtures. Though work is in progress, no data are available at this point in time for the five remaining test mixtures. Reported are: visual observations on aged sealed tubes, gas chromatographic analyses on the vapor phase contents of the tubes, chloride ion contents of HCFC containing mixtures or fluoride ion contents of HFC mixtures, and total acid number values and infrared analysis results for mixtures containing ester lubricants.

Huttenlocher, D.F.

1992-07-10

30

Estimation of Freezing Point of Hydrocarbon and Hydrofluorocarbon Mixtures for Mixed Refrigerant jt Cryocooler  

NASA Astrophysics Data System (ADS)

Estimating the freezing point of refrigerant is an essential part in designing an MR JT (Mixed refrigerant Joule-Thomson) cryocooler to prevent itself from clogging and to operate with stability. There were researches on estimating freezing point, but some of them resulted in the wrong prediction of clogging. In this paper, the freezing point of the MR is precisely estimated with caution of clogging. The solubility of HC (hydrocarbon) and HFC (hydrofluorocarbon) mixture components are obtained with their activity coefficients, which represent the molecular interaction among the components. The freezing points of the MR JT cryocooler are systematically investigated in the operating temperature range from 70 K to 90 K.

Hwang, G.; Lee, J.; Jeong, S.

2010-04-01

31

Nearly Azeotropic Mixtures To Replace Refrigerant 12  

NASA Technical Reports Server (NTRS)

Number of nearly azeotropic fluid mixtures have saturation pressures similar to Refrigerant 12 while being about 2 percent as damaging to ozone layer. Five mixtures of R134a, R152a, R124, and R142b have low boiling-point spreads, low toxicity, and low ozone-damaging capability, are nonflammable, and more compatible with conventional oils than R134a. Pressure of combinations nearly equal to R12, and mixtures may be good "drop-in substitutes". Overall composition not altered by leakage. Usable in commercial, automotive, and household refrigerators and air conditioners.

Jones, Jack A.

1992-01-01

32

Ideal-Gas Heat Capacity Values and Equations for Hydrofluorocarbon (HFC) Refrigerants Based on Speed-of-Sound Measurements  

Microsoft Academic Search

Final values of ideal-gas heat capacity c0p derived from speed-of-sound measurements using an acoustic spherical resonator and equations of c0p as a simple function of temperature are provided from an overall assessment of speed-of-sound measurements for five hydrofluorocarbon (HFC) refrigerants, difluoromethane (R32), pentafluoroethane (R125), 1,1,1,2-tetrafluoroethane (R134a), 1,1,1-trifluoroethane (R143a), and 1,1-difluoroethane (R152a). Some of the experimental results had systematic errors in

H. Sato; T. Kojima; K. Ogawa

2002-01-01

33

Estimated 2017 Refrigerant Emissions of 2,3,3,3-Tetrafluoropropene (HFC-1234yf) in the United States Resulting from Automobile Air Conditioning  

EPA Science Inventory

In response to recent regulations and concern over climate change, the global automotive community is evaluating alternatives to the current refrigerant used in automobile air conditioning units, 1,1,1,2-tetrafluoroethane, HFC-134a. One potential alternative is 2,3,3,3-tetrafluor...

34

Performance of environmentally friendly CFC-12 replacements for refrigerator/freezers  

SciTech Connect

The paper presents the capacity and energy consumption of refrigerant replacements for HFC-134a and/or CFC-12 as determined by experimental testing and analysis. Refrigerator/freezer (R/F) tests were run according to the Association of Home Appliance Manufacturer`s testing conditions in an environmental test chamber. The charge was optimized for each refrigerant, and the results were compared to those for HFC-134a and CFC-12. The numerical model and experiment results were compared to verify the model. The paper investigates HFC-245cb/HFC-134 and HFC-134. Computer modeling predicts that these azeotropes will perform similarly to HFC-134a, which has a higher global warming potential than any of the mixtures except HFC-245cb/HFC-134.

Baskin, E.; Bayoglu, E.S.; Delafield, F.R.

1995-12-31

35

Chemical and thermal stability of refrigerant-lubricant mixtures with metals. Quarterly report, 1 April 1992--30 June 1992  

SciTech Connect

This report presents completed sealed tube stability test results for the following eight refrigerant/lubricant mixtures: R-22/mineral oil; R-124/alkylbenzene; R-134a/pentaerythritol (PE) ester (mixed acid); R- 134a/PE (branched acid); R-134a/ PE (100 cSt viscosity); R- 142b/alkylbenzene; R-143a/ PE (branched acid); R-152a/alkylbenzene. Partial results are shown for an additional eight refrigerant-lubricant mixtures. Though work is in progress, no data are available at this point in time for the five remaining test mixtures. Reported are: visual observations on aged sealed tubes, gas chromatographic analyses on the vapor phase contents of the tubes, chloride ion contents of HCFC containing mixtures or fluoride ion contents of HFC mixtures, and total acid number values and infrared analysis results for mixtures containing ester lubricants.

Huttenlocher, D.F.

1992-07-10

36

Theoretical Analysis of Heat Pump Cycle Characteristics with Pure Refrigerants and Binary Refrigerant Mixtures  

NASA Astrophysics Data System (ADS)

In recent years there has been an increasing interest of the use of nonazeotropic binary mixtures to improve performance in heat pump systems, and to restrict the consumption of chlorofluorocarbon (CFC) refrigerants as internationally agreed-upon in the Montreal Protocol. However, the available knowledge on the thermophysical properties of mixtures is very much limited particularly with respect to quantitative information. In order to systematize cycle performance with Refrigerant 12 (CCl2F2) + Refrigerant 22 (CHClF2) and Refrigerant 22 + Refrigerant 114 (CClF2-CClF2) systems which are technically important halogenated refrigerant mixtures, the heat pump cycle analysis in case of using these mixtures was theoretically studied. It became clear that the maximum coefficients of performance with various pure refrigerants and binary refrigerant mixtures were obtained at the reduced condensing temperature being 0.9 when the same temperature difference between condensing and evaporating temperature was chosen.

Kagawa, Noboru; Uematsu, Masahiko; Watanabe, Koichi

37

Chemical and thermal stability of refrigerant-lubricant mixture with metal  

SciTech Connect

This report presents completed sealed tube stability test results for the R-123/mineral oil mixture and preliminary results for seven of the eighteen contracted refrigerant-lubricant mixtures. The R-123 mixture was tested at 105, 150, and 175{degrees}C. The results obtained indicate that prolonged exposure to temperatures of about 150{degree}C and higher will lead to rapid chemical deterioration of the R-123/mineral oil system. Chlorotrifluoroethane (R-133a) and trifluoroethane (R-143a) have been identified as decomposition products of R-123. Testing at 150 and 175{degrees}C have been completed for the HCFC refrigerants R-22, R-124, and R-142b with either mineral oil or alkylbenzene lubricants. These mixtures were very stable at the indicated temperatures. Testing at a higher temperature level will be necessary to define their upper temperature limits. Similarily, partial test results are available for HFC refrigerants R-32, R-125, R-134a (two esters), and R-143a with pentaerythritol ester lubricants at the 150 and 175{degrees}C temperature levels. Again, all five mixtures were found to be extremely stable at the test temperatures and additional testing will be needed to establish their upper temperature limits.

Huttenlocher, D.F. (Spauschus Associates, Inc., Atlanta, GA (United States))

1992-03-31

38

Evaluation of a two-evaporator refrigerator-freezer using nonazeotropic refrigerant mixtures. Final report  

SciTech Connect

The temperature of a nonazeotropic mixture of refrigerants changes during evaporation and condensation at constant pressure. Refrigerant mixtures offer the potential of better matching the two temperature levels (approximately 38/sup 0/F in the fresh food compartment and 5/sup 0/F in the freezer) in a household refrigerator-freezer than a single refrigerant. This feature may reduce energy consumption. The objective of this project was to investigate, through laboratory testing, the feasibility of using refrigerant mixtures to save energy. The unit selected for testing was the Amana ESTR-18D, two evaporator refrigerator-freezer developed jointly under US Department of Energy sponsorship by Arthur D. Little, Inc., and Amana Refrigeration, Inc. Tests using two mixture concentrations of R22 and R114 refrigerants demonstrated reliable refrigerator performance but no appreciable energy savings. An analytical model was developed to identify modifications to the refrigeration system in order to realize the benefits of mixed refrigerants. Based on the model, the expansion device was modified to reduce the system pressure ratio. Predicted benefits in evaporator heat exchanger effectiveness were observed, but were offset by the reduced heat capacity and density of the mixtures compared to the standard refrigerant. No energy savings were demonstrated with the ESTR-18D test unit. 9 references, 6 figures, 9 tables.

Not Available

1984-09-01

39

Experimental analysis of refrigerant mixtures flow through adiabatic capillary tubes  

Microsoft Academic Search

This paper presents an experimental study on HCFC 22 alternative refrigerant mixtures flow through capillary tubes. Results for R-410A and R-407C show that the main operational parameters affect in a similar way the performance of capillary tubes for both refrigerants. The influence of geometry on the bahaviour of capillary tubes in refrigeration systems is characterised. An analysis on the differences

Flávio Augusto Sanzovo Fiorelli; Alex Alberto Silva Huerta; Otávio de Mattos Silvares

2002-01-01

40

REFLEAK: NIST Leak/Recharge Simulation Program for Refrigerant Mixtures  

National Institute of Standards and Technology Data Gateway

SRD 73 NIST REFLEAK: NIST Leak/Recharge Simulation Program for Refrigerant Mixtures (PC database for purchase)   REFLEAK estimates composition changes of zeotropic mixtures in leak and recharge processes.

41

Evaluation of vapor compression cycles using nonazeotropic refrigerant mixtures  

Microsoft Academic Search

A comprehensive investigation is carried out, on a systematic and consistent basis, to explore a range of advanced heat pump cycle concepts using nonazeotropic refrigerants for COP enhancement and capacity modulation along with the trade-offs associated with refrigerant mixture selection. The objectives of the study were to: identify candidate nonazeotropic mixtures and advanced heat pump cycle concepts with emphasis on

Richard L. Merriam

1988-01-01

42

Energy and global warming impacts of HFC refrigerants and emerging technologies: TEWI-III  

SciTech Connect

The use of hydrofluorocarbons (BFCs) which were developed as alternative refrigerants and insulating foam blowing agents to replace chlorofluorocarbons (CFCs) is now being affected by scientific investigations of greenhouse warming and questions about the effects of refrigerants and blowing agents on global warming. A Total Equivalent Warming Impact (TEWI) assessment analyzes the environmental affects of these halogenated working fluids in energy consuming applications by combining a direct effect resulting from the inadvertent release of HFCs to the atmosphere with an indirect effect resulting from the combustion of fossil fuels needed to provide the energy to operate equipment using these compounds as working fluids. TEWI is a more balanced measure of environmental impact because it is not based solely on the global warming potential (GWP) of the working fluid. It also shows the environmental benefit of efficient technologies that result in less CO{sub 2} generation and eventual emission to the earth`s atmosphere. The goal of TEWI is to assess total global warming impact of all the gases released to the atmosphere, including CO{sub 2} emissions from energy conversion. Alternative chemicals and technologies have been proposed as substitutes for HFCs in the vapor-compression cycle for refrigeration and air conditioning and for polymer foams in appliance and building insulations which claim substantial environmental benefits. Among these alternatives are: (1) Hydrocarbon (HC) refrigerants and blowing agents which have zero ozone depleting potential and a negligible global warming potential, (2) CO{sub 2} as a refrigerant and blowing agent, (3) Ammonia (NH{sub 3}) vapor compression systems, (4) Absorption chiller and heat pumping cycles using ammonia/water or lithium bromide/water, and (5) Evacuated panel insulations. This paper summarizes major results and conclusions of the detailed final report on the TEWI-111 study.

Sand, J.R.; Fischer, S.K.; Baxter, V.D.

1997-06-01

43

Solubility, viscosity and density of refrigerant/lubricant mixtures. Quarterly technical progress report, 1 October--31 December 1992  

SciTech Connect

This report presents results on low refrigerant concentration (70, 80, 90, and 100 weight percent lubricant) mixtures of the following fluids: CFC-12/ISO 32 naphthenic mineral oil; HCFC-22/ISO 32 naphthenic mineral oil; and HFC-134a/ISO 32 pentaerythritol ester mixed acid. These data have been reduced to engineering form and are presented in the form of a Daniel Chart. Scatter diagrams are given for the first fluid listed above, with the intent of illustrating the quality of data as well as providing the rationale for selecting the particular functional forms chosen to represent the experimental data. Equations are given along with statistical measures of goodness of fit.

Henderson, D.R.

1993-01-01

44

Performance of a Throttle Cycle Refrigerator with Nitrogen-Hydrocarbon and Argon-Hydrocarbon Mixtures  

NASA Astrophysics Data System (ADS)

Throttle cycle refrigerators are a class of vapor compression refrigerators that can provide refrigeration at cryogenic temperatures and operate with refrigerant mixtures. The performance of our prototype refrigerators with nitrogen-hydrocarbon, nitrogen-hydrocarbon-helium and argon-hydrocarbon refrigerant mixtures is presented in this paper.

Venkatarathnam, G.; Senthil Kumar, P.; Srinivasa Murthy, S.

2004-06-01

45

Theoretical Analysis of Heat Pump Cycle Characteristics with Pure Refrigerants and Binary Refrigerant Mixtures  

NASA Astrophysics Data System (ADS)

In recent years there has been an increasing interest of the use of nonazeotropic binary mixtures to improve performance in heat pump systems, and to restrict the consumption of chlorofluorocarbon (CFC) refrigerants as internationally agreed-upon in the Montreal Protocol. However, the available knowledge on the thermophysical properties of mixtures is very much limited particularly with respect to quantitative information. In order to examine cycle performance for Refrigerant 12 (CCl2F2) + Refrigerant 22 (CHClF2) and Refrigerant 22 + Refrigerant 114 (CClF2-CClF2) systems which are technically important halogenated refrigerant mixtures, the heat pump cycle analysis in case of using pure Refrigerants 12, 22 and 114 was theoretically carried out in the present paper. For the purpose of systematizing the heat pump cycle characteristics with pure refrigerants, the cycle analysis for Refrigerants 502, 13B1, 152a, 717 (NH3) and 290 (C3H8) was also examined. It became clear that the maximum coefficients of performance with various refrigerants were obtained at the reduced condensing temperature being 0.9 when the same temperature difference between condensing and evaporating temperature was chosen.

Kagawa, Noboru; Uematsu, Masahiko; Watanabe, Koichi

46

Evaluation of vapor compression cycles using nonazeotropic refrigerant mixtures  

NASA Astrophysics Data System (ADS)

A comprehensive investigation is carried out, on a systematic and consistent basis, to explore a range of advanced heat pump cycle concepts using nonazeotropic refrigerants for COP enhancement and capacity modulation along with the trade-offs associated with refrigerant mixture selection. The objectives of the study were to: identify candidate nonazeotropic mixtures and advanced heat pump cycle concepts with emphasis on their potential for single-speed capacity modulation with mixture composition control; assess the effect of conjunction with nonazeotropic mixture cycles; evaluate the cycles analytically and recommend the most promising cycles and mixtures for further development; and provide recommendations relating to the needs for additional refrigerant property data, experimental studies of basic heat transfer phenomena with mixed refrigerants, development of system components, and/or more detailed modeling of specific components.

Merriam, Richard L.

47

A Dynamic Model of a Vapor Compression Refrigeration Cycle using Zeotropic Refrigerant Mixtures  

NASA Astrophysics Data System (ADS)

A dynamic model is developed for a vapor compression refrigeration cycle with zeotropic refrigerant mixtures. In this model, the refrigeration cycle is represented by elements, such as a compressor and heat exchangers and connecting points of each element. The continuity equation of pressure and the conservation equation of mass and energy at each connecting point are used as the equations of the refrigeration cycle. To solve the equations, inlet pressure, inlet mass flow rate or outlet pressure of each element, enthalpy and the circulating composition of each connecting point are modified. In this way, a versatile modeling of refrigeration cycles is realized. In addition, including conservation of mass of each composition of zeotropic refrigerant mixtures in this model, dynamic characteristics of compositions are calculated.

Unezaki, Fumitake; Matsuoka, Fumio

48

The Influence of the Lubricant Mixture into a Refrigerant on the Condensation Heat Transfer in Tube  

NASA Astrophysics Data System (ADS)

In a refrigerator and an air conditioner, it is a well-known fact that the contamination of lubricant into a pure refrigerant has a great influence on the heat transfer characteristics and two-phase flow behavior at the condenser and evaporator. However, up to now, in the most of heat exchanger design, the refrigerant has been regarded as a pure one. On the other hand, a recent condenser tube diameter tends to be fine to overcome the various demands on the compactness and the high performance, especially required for the alternative refrigerant. Unfortunately, quantitative studies of the tube less than 6 mm in diameter were insufficient, moreover, only few studies have been made including the effect of the oil contamination on the condensation heat transfer. In this study, we employed HFC134a as a refrigerant and PAG-oil as a lubricant and experiments with a flat tube and three kinds of circular tube which has different diameters were made. By using the flow visualization data, a new flow pattern map being applicable both of a pure and oil-lubricant mixture was proposed. Moreover, by examining the local heat transfer coefficient and pressure drop, the most sensitive flow pattern affected by contamination of lubricant was specified and the detailed discussion on the quantitative effect of oil contamination on condensation heat transfer including the effect of tube geometry was carried out. Finally, based on these results, new correlation for heat transfer and pressure drop was suggested, and it predicted our data successfully well up to a mass flux of 150kg/(m2•s.)

Katsuta, Masafumi; Miyai, Ryo; Komatsu, Tomohiro; Kawai, Akinari

49

Frontiers in thermoacoustic refrigeration and mixture separation  

E-print Network

waves. Stirling's "hot-air engine" of the early 19th century was one of the first heat engines to use oscillating thermodynamics in a gas in a sealed system. Since then, many related engines and refrigerators have been developed. The efficient, mature members of this family of engines and refrigerators are used

50

Flow Characteristics of Refrigerant-Oil Mixture through Narrow Clearance  

NASA Astrophysics Data System (ADS)

Leakage flow through a narrow clearance in refrigerant compressors is a flow of refrigeration oil mixed with refrigerant. Its characteristics are very complicated because there is a possibility of a separation of vapor refrigerant from the oil according to a change of refrigerant solubility with pressure drop in the clearance. In this study, we studied the flow characteristics of refrigerant-oil miture through the narrow clearance experimentally and theoreticalIy. At first we investigated the characteristics of the two-phase flow through the narrow clearance by using a two-phase analytical model. The characteristics were also analyzed by a single phase model and the limitation of the homogeneous model was discussed by comparing results of the both models. On the other hand, the flow characteristics were measured by using an experimental channel having the narrow clearance. The followings were clarified. (1) The separation of vapor refrigerant from the liquid mixture in the channel does not progress according to the change of saturation solubility and the condition of the flowing liquid is in a super saturated condition. (2) The diverging shape of the channel induces the vapor separation. (3) The vapor separation decreases flow rate of the liquid mixture through the clearance, and the flow rate can be estimated by the analysis with an appropriate separation ratio.

Fukuta, Mitsuhiro; Yanagisawa, Tadashi; Shimizu, Takashi; Date, Hisashi; Ogi, Yasuhiro

51

Laboratory evaluation of an ozone-safe nonazeotropic refrigerant mixture in a Lorenz-Meutzner refrigerator freezer design  

Microsoft Academic Search

The Lorenz-Meutzner refrigerator freezer (RF) circuit has been proposed as a design which would operate with nonazeotropic refrigerant mixtures (NARMS) and significantly increase the thermodynamic efficiency of household refrigerators. Several ozone-safe and more environmentally acceptable refrigerants are known which could be blended into a NARM to replace R-12 for this domestic refrigeration application. Laboratory tests were performed on a Lorenz-Meutzner

J. R. Sand; E. A. Vineyard; V. D. Baxter

1992-01-01

52

Artificial neural network analysis of heat pumps using refrigerant mixtures  

Microsoft Academic Search

In this study, we have investigated the performance of a vapor compression heat pump with different ratios of R12\\/R22 refrigerant mixtures using artificial neural networks (ANN). Experimental studies were completed to obtain training and test data. Mixing ratio, evaporator inlet temperature and condenser pressure were used as input layer, while the outputs are coefficient of performance (COP) and rational efficiency

Erol Arcaklio?lu; Ali Eri?en; Ramazan Yilmaz

2004-01-01

53

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...

54

Chemical and thermal stability of refrigerant-lubricant mixture with metal. Materials compatibility and lubricants research on CFC-refrigerant substitutes: Quarterly report, 1 February 1992--31 March 1992  

SciTech Connect

This report presents completed sealed tube stability test results for the R-123/mineral oil mixture and preliminary results for seven of the eighteen contracted refrigerant-lubricant mixtures. The R-123 mixture was tested at 105, 150, and 175{degrees}C. The results obtained indicate that prolonged exposure to temperatures of about 150{degree}C and higher will lead to rapid chemical deterioration of the R-123/mineral oil system. Chlorotrifluoroethane (R-133a) and trifluoroethane (R-143a) have been identified as decomposition products of R-123. Testing at 150 and 175{degrees}C have been completed for the HCFC refrigerants R-22, R-124, and R-142b with either mineral oil or alkylbenzene lubricants. These mixtures were very stable at the indicated temperatures. Testing at a higher temperature level will be necessary to define their upper temperature limits. Similarily, partial test results are available for HFC refrigerants R-32, R-125, R-134a (two esters), and R-143a with pentaerythritol ester lubricants at the 150 and 175{degrees}C temperature levels. Again, all five mixtures were found to be extremely stable at the test temperatures and additional testing will be needed to establish their upper temperature limits.

Huttenlocher, D.F. [Spauschus Associates, Inc., Atlanta, GA (United States)

1992-03-31

55

A Dynamic Model of a Vapor Compression Refrigeration Cycle using Zeotropic Refrigerant Mixtures  

NASA Astrophysics Data System (ADS)

In order to prove the effectiveness of the developed model, reported in the first report, about dynamics of a vapor compression refrigeration cycle with zeotropic refrigerant mixtures, simulation results are compared with the experimental results obtained for R-407C (R-32/R-125/R-134a=23/25/52wt%).The simulation results are consistent well with the experimental results. As a result of the numerical analysis of dynamic characteristics of composition changing, the variation of compositions in the refrigeration cycle is caused by the variation of the existing compositions of accumulator. The time constant of the composition is approximately equal to the time constant of the pressure and the mass distribution.

Unezaki, Fumitake; Matsuoka, Fumio

56

Evaluation of nonazeotropic refrigerant mixtures for capacity modulation  

SciTech Connect

A test program is underway at the Oak Ridge National Laboratory (ORNL) to evaluate the potential performance improvements from using nonazeotropic refrigerant mixtures in residential heat pumps. The goals of the research effort are to achieve (1) capacity control by adjusting the composition, (2) increased capacity, relative to R22, at low ambient temperatures, and (3) matching of the refrigerant temperature differentials to the source and sink fluid temperature differentials. Performance improvements are expected to result from decreasing the cycling losses and the amount of resistance heat required at low ambient temperatures along with reducing the irreversibilities in the heat exchangers. Initial results for a mixture of R13B1/R152a show a potential capacity modulation from 12431 Btu/h (3643 W) at 17 F (/minus/8.3/degree/C) to 8550 Btu/h (2506 W) at 47 F (8.3/degree/C) in heating and from 7451 Btu/h (2184 W) at 82 F (27. 8/degree/C) to 9188 Btu/h (2693 W) at 95 F (35/degree/C) in cooling. Other refrigerant pairs which are safer from an ozone depletion standpoint are under consideration for later testing. 10 refs., 5 figs., 4 tabs.

Vineyard, E.A.; Sand, J.R.

1988-01-01

57

Simulation of nonazeotropic refrigerant mixtures for use in a dual-circuit refrigerator\\/freezer with countercurrent heat exchanges  

Microsoft Academic Search

The paper discusses the simulation of Non-azeotropic Refrigerant Mixtures (NARMs) for use in a dual-circuit refrigerator\\/freezer (RF) with countercurrent heat exchangers. The simulated RF has two complete and independent refrigeration cycles for its two compartments. It uses a NARM in each cycle and countercurrent heat exchangers throughout. In a standard cabinet, the RF is simulated to provide energy savings of

J. C. Bare; C. L. Gage; R. Radermacher; D. S. Jung

1992-01-01

58

Simulation of nonazeotropic refrigerant mixtures for use in a dual-circuit refrigerator\\/freezer with countercurrent heat exchangers  

Microsoft Academic Search

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. In a standard cabinet, this RF appears to provide energy savings of 24%, compared to current U.S. RF designs. The NARMs modeled with the best performance

J. C. Bare; C. L. Gage; R. Radermacher; D. Jung

1991-01-01

59

Experimental results with hydrocarbon mixtures in domestic refrigerator/freezers  

SciTech Connect

With propane/n-butane blends, energy savings up to 6% were achieved in a domestic refrigerator/freezer compared to the baseline test with R-12. The hydrocarbon mixtures were tested as drop-in substitutes. All the hardware remained the same, only the capillary tube was lengthened to control the flow rate. The additional capillary tube length, the blend concentration, and the charge were adjusted to determine the optimum performance. The best result of 2.29 kWh/day was achieved with a blend of 70% R-290 and 30% R-600, 70 g of charge, and an additional capillary tube length of 5 ft.

Liu, B.Y.; Tomasek, M.L.; Radermacher, R. [Univ. of Maryland, College Park, MD (United States). Center for Environmental Energy Engineering

1995-08-01

60

Evaluation of supplementary\\/retrofit refrigerants for automobile air-conditioners charged with CFC12  

Microsoft Academic Search

In this study, thermodynamic performance of supplementary\\/retrofit refrigerant mixtures for CFC12 used in existing automobile air-conditioners was examined. A thermodynamic computer analysis of an automobile air-conditioner was carried out for the initial screening of possible mixture candidates, and refrigerant mixtures composed of HCFC22, HFC134a, HCFC142b, RE170 (dimethylether), HC290 (propane), and HC600a (iso-butane) were proposed to supplement CFC12. Also a breadboard

Dongsoo Jung; Hyunchul Lee

1999-01-01

61

Thermal Response Of TXV-controlled Heat Pump Systems Operating With Refrigerant Mixtures  

Microsoft Academic Search

Research into the possibility of using azeotropic and nonazeotropic refrigerant mixtures in heat pump systems has gained enormous popularity in the past feu decades. Uhile past studies have investigated the increase in system capacity from using refrigerant blends, these studies have neglected to discuss the problems associated uith metering such mixtures, especially in the case of the nonazeotropic pairs. It

Lawrence R. Grzyll; John J. Silvestri; Isaac Schantz

1990-01-01

62

Evaluation of ozone-friendly hydrofluoropropane-based zeotropic refrigerant mixtures in a Lorenz-Meutzner refrigerator/freezer  

SciTech Connect

The design of the Lorenz-Meutzner refrigerator/freezer has two evaporators (located in the freezer and fresh food compartments), which makes it a leading candidate for use of zeotropic refrigerant mixtures. Zeotropic mixtures can have significant temperature glides during evaporation and condensation. Performance of the zeotropic mixture can be maximized in the LM design by permitting the lower end of the temperature glide to occur in the freezer compartment evaporator and the higher end in the fresh food compartment evaporator. Several hydrofluoropropane-based zeotropes (e.g., R-227 ea/R-245ca) have been shown through steady-state modeling to outperform R-134a by up to 15%. Results from previous testing of this refrigerator/freezer using R-32/R-124 (zeotropic mixture) were published in an ASHRAE paper (Sand et al. 1993). Their results showed performance gains of approximately 3% over R-12. In the study presented in this paper, the Lorenz-Meutzner refrigerator/freezer having two evaporators and two intercoolers was experimentally tested in an environmental chamber according to Association of Home Appliance Manufacturers/Department of Energy (AHAM/DOE) testing standards using several hydrofluoropropane-based zeotropic mixtures. The results are compared to baseline testing with R-134a. The R-245ca/R-134a and R-245ca/R-152a mixtures performed comparably to R-134a. R-245ca/R-270 outperformed all zeotropic mixtures and R-134a by at least 16%. Also, a refrigerant sampling loop is added to determine the running composition of the mixture and its effects on the performance of the refrigerator/freezer.

Baskin, E. [Environmental Protection Agency, Research Triangle Park, NC (United States); Bayoglu, E.S.; Delafield, F.R. [Acurex Environmental Corp., Durham, NC (United States)

1997-12-31

63

Influence of Refrigerant Oil on Evaporator Performance  

NASA Astrophysics Data System (ADS)

Because of the phase-out CFC Freon series required by Montreal Protocal, the conversion to HFC alternatives for vapor compression refrigeration system have been in progress. The each component design of these system should need to be reassessed, however, to improve the performance and compactness of the evaporator, an influence of the refrigerant oil on the refrigerant side heat transfer remains as an important and unsolved subject. In this article, the previous research progresses on the thermophysical properties, two-phase flow regimes and heat transfer in evaporator tube of refrigerant and oil mixture are briefly reviewed and the ability of these results to the combination of the alternative refrigerant and oil system is discussed. According to the review, the limited quantitative agreements were obtained from the perfect miscible refrigerant and oil mixture and, in particular, the much detailed research on the heat transfer mechanisms are required in future.

Kim, Jong Soo; Katsuta, Masafumi

64

Laboratory evaluation of an ozone-safe nonazeotropic refrigerant mixture in a Lorenz-Meutzner refrigerator freezer design  

SciTech Connect

The Lorenz-Meutzner refrigerator freezer (RF) circuit has been proposed as a design which would operate with nonazcotropic refrigerant mixtures (NARMS) and significantly increase the thermodynamic efficiency of household refrigerators. Several ozone-safe and more environmentally acceptable refrigerants are known which could be blended into a NARM to replace R-12 for this domestic refrigeration application. Laboratory tests were performed on a Lorenz-Meutzner (L-M) RF using an R-32/R-124 NARM. Comparisons are made between the baseline performance of the refrigerator with R-12 before it was modified to the L-Ni design and that of the L-M circuit operating with R-12 and the NARM. Circuiting and component changes resulting from initial testing of this unit are described. Computer modeling and compressor calorimeter results for R-12 and the NARM used in the test unit are also presented. Small performance gains ({approx} 3%) are seen for the NARM over R-12 in the same refrigerator freezer circuit. Modeling results and steady-state data suggest larger improvements ({approx} 15%) are possible. It is felt that the larger improvements predicted from modeling and compressor calorimetry data are not being realized due to poor heat transfer and refrigerant circuiting arrangements.

Sand, J.R.; Vineyard, E.A.; Baxter, V.D.

1992-11-01

65

Laboratory evaluation of an ozone-safe nonazeotropic refrigerant mixture in a Lorenz-Meutzner refrigerator freezer design  

SciTech Connect

The Lorenz-Meutzner refrigerator freezer (RF) circuit has been proposed as a design which would operate with nonazcotropic refrigerant mixtures (NARMS) and significantly increase the thermodynamic efficiency of household refrigerators. Several ozone-safe and more environmentally acceptable refrigerants are known which could be blended into a NARM to replace R-12 for this domestic refrigeration application. Laboratory tests were performed on a Lorenz-Meutzner (L-M) RF using an R-32/R-124 NARM. Comparisons are made between the baseline performance of the refrigerator with R-12 before it was modified to the L-Ni design and that of the L-M circuit operating with R-12 and the NARM. Circuiting and component changes resulting from initial testing of this unit are described. Computer modeling and compressor calorimeter results for R-12 and the NARM used in the test unit are also presented. Small performance gains ({approx} 3%) are seen for the NARM over R-12 in the same refrigerator freezer circuit. Modeling results and steady-state data suggest larger improvements ({approx} 15%) are possible. It is felt that the larger improvements predicted from modeling and compressor calorimetry data are not being realized due to poor heat transfer and refrigerant circuiting arrangements.

Sand, J.R.; Vineyard, E.A.; Baxter, V.D.

1992-01-01

66

Performance of chlorine-free binary zeotropic refrigerant mixtures in a heat pump  

Microsoft Academic Search

The phase-out of the currently used refrigerants during the next decade requires fast and accurate methods to evaluate possible alternatives for the existing refrigerants. The report investigates possible replacement refrigerants for R22, where the replacements are binary zeotropic mixtures of the following hydrofluorocarbons (HFCs): R23, R32, R125, R134a, and R152a. The method, that was chosen, is based on three steps:

J. Pannock; D. A. Didion

1991-01-01

67

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...

68

Simulation of nonazeotropic refrigerant mixtures for use in a dual-circuit refrigerator/freezer with countercurrent heat exchangers  

SciTech Connect

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. In a standard cabinet, this RF appears to provide energy savings of 24%, compared to current U.S. RF designs. The NARMs modeled with the best performance included R-32/-152a, R-22/-142b, and R-32/-142b. An 18% improvement can be expected from the dual-circuit system using R-12 alone, and an additional 6% improvement can be gained by replacing R-12 with the selected NARMs in countercurrent heat exchangers. The advantages of the system include greatly reduced energy consumption, easy temperature and humidity control for each compartment, no humidity or odors transferred between compartments, and increased time between defrost cycles.

Bare, J.C.; Gage, C.L.; Radermacher, R.; Jung, D.

1991-01-01

69

TRANSPORT PROPERTY MEASUREMENTS OF HFC-236EA  

EPA Science Inventory

The report gives results of an evaluation of transport properties of 1,1,1,2,3,3,-hexafluoropropane (HFC-236ea), with liquid viscosity and thermal conductivity being the two main transport properties of interest. In addition, the specific heat and density of refrigerant/lubrican...

70

TRANSPORT PROPERTY MEASUREMENTS OF HFC-236EA  

EPA Science Inventory

The report gives results of an evaluation of transport properties of 1, 1, 1, 2, 3, 3-hexafluoropropane (HFC-236ea), with liquid viscosity and thermal conductivity being the two main transport properties of interest. In addition, the specific heat and density of refrigerant/lubri...

71

FLAME SUPPRESSION AND LUBRICANT INTERACTION OF HYDROCARBON MIXTURES FOR HOUSEHOLD REFRIGERANT/FREEZERS  

EPA Science Inventory

The paper discusses the flame suppression and lubricant interaction of hydrocarbon (HC) mixtures for household refrigerator/freezers (R/Fs). he work focuses on blending the minimum amount of a fluoroiodocarbon (FIC) with previously optimized R/F-tested HC mixtures to reduce their...

72

Prediction of Heat Transfer Characteristics of Binary Refrigerant Mixtures in a Plate-Fin Condenser  

NASA Astrophysics Data System (ADS)

The heat transfer characteristics of binary refrigerant mixtures in a plate-fin condenser are experimentally investigated using a vapor compression heat transformer, in which binary refrigerant mixtures of R 134a/ R 123 are used as the working fluid and water is used as both heat sink and source. Pure refrigerants of R 22 and R 134a are also tested as the working fluid. The experimental ranges of heat flux and mass velocity are from 2 to 20 kW/m2 and from 50 to 100 kg/m2s, respectively. The heat transfer characteristics of the condensation and vapor single-phase flow of pure and mixed refrigerants are discussed, and empirical correlation equations of the condensate heat transfer and vapor single-phase heat transfer are proposed. The correlation equation of water-side heat transfer is also presented. Combining these correlation equations with a correlation equation of vapor mass transfer based on the Chilton-Colburn analogy, a prediction model for condensation of the binary refrigerant mixtures in a plate-fin heat exchanger is developed based on the assumption that the phase equilibrium is only established at the vapor-liquid interface. The calculation results for the pure and mixed refrigerants agree well with the present experimental data. The mass transfer characteristics are also revealed from the calculation results.

Yara, Tomoyasu; Koyama, Shigeru

73

Modeling of a heat pump charged with a non-azeotropic refrigerant mixture  

NASA Astrophysics Data System (ADS)

An analysis of the vapor compression cycle and the main components of an air-to-air heat pump charged with a binary non-azeotropic mixture has been performed for steady-state operation. The general heat pump simulation model HPBI has been formulated which is based on independent, analytical models of system components and the logic linking them together. The logic of the program requires an iterative solution of refrigerant pressure and enthalpy balances, and refrigerant mixture and individual mixture component mass inventories. The modeling effort emphasis was on the local thermodynamic phenomena which were described by fundamental heat transfer equations and equation of state relationships among material properties. In the compressor model several refrigerant locations were identified and the processes taking place between these locations accounted for all significant heat and pressure losses.

Domanski, P.

1986-01-01

74

TESTING OF REFRIGERANT MIXTURES IN RESIDENTIAL HEAT PUMPS  

EPA Science Inventory

The report gives results of an investigation of four possibilities for replacing Hydrochlorofluorocarbon-22 (HCFC-22) with the non-ozone-depleting new refrigerants R-407D and R-407C in residential heat pumps. The first and simplest scenario was a retrofit with no hardware modific...

75

Performance of chlorine-free binary zeotropic refrigerant mixtures in a heat pump  

SciTech Connect

The phase-out of the currently used refrigerants during the next decade requires fast and accurate methods to evaluate possible alternatives for the existing refrigerants. The report investigates possible replacement refrigerants for R22, where the replacements are binary zeotropic mixtures of the following hydrofluorocarbons (HFCs): R23, R32, R125, R134a, and R152a. The method, that was chosen, is based on three steps: (1) determining possible mixture components, (2) evaluating all fifteen possible mixtures using a simulation program developed by NIST and determining the best performing mixtures, (3) evaluating the best performing mixtures in a NIST built test facility. Following the path, two refrigerant mixtures, R32/R134a and R32/R152a were found to perform better than R22 with respect to COP and volumetric capacity for certain composition ranges. The used simulation model proved to be a very precise tool in finding possible replacement fluids and their possible performance advantages. The results give the confidence that this time saving combination of simulation and testing is a very powerful engineering tool.

Pannock, J.; Didion, D.A.

1991-12-01

76

Accelerated screening methods for determining chemical and thermal stability of refrigerant-lubricant mixtures, Part 1: Method assessment. Final report  

SciTech Connect

This report presents results of a literature search performed to identify analytical techniques suitable for accelerated screening of chemical and thermal stabilities of different refrigerant/lubricant combinations. Search focused on three areas: Chemical stability data of HFC-134a and other non-chlorine containing refrigerant candidates; chemical stability data of CFC-12, HCFC-22, and other chlorine containing refrigerants; and accelerated thermal analytical techniques. Literature was catalogued and an abstract was written for each journal article or technical report. Several thermal analytical techniques were identified as candidates for development into accelerated screening tests. They are easy to operate, are common to most laboratories, and are expected to produce refrigerant/lubricant stability evaluations which agree with the current stability test ANSI/ASHRAE (American National Standards Institute/American Society of Heating, Refrigerating, and Air-Conditioning Engineers) Standard 97-1989, ``Sealed Glass Tube Method to Test the Chemical Stability of Material for Use Within Refrigerant Systems.`` Initial results of one accelerated thermal analytical candidate, DTA, are presented for CFC-12/mineral oil and HCFC-22/mineral oil combinations. Also described is research which will be performed in Part II to optimize the selected candidate.

Kauffman, R.

1993-04-01

77

Simulation of nonazeotropic refrigerant mixtures for use in a dual-circuit refrigerator/freezer with countercurrent heat exchanges  

SciTech Connect

The paper discusses the simulation of Non-azeotropic Refrigerant Mixtures (NARMs) for use in a dual-circuit refrigerator/freezer (RF) with countercurrent heat exchangers. The simulated RF has two complete and independent refrigeration cycles for its two compartments. It uses a NARM in each cycle and countercurrent heat exchangers throughout. In a standard cabinet, the RF is simulated to provide energy savings of 24 percent compared to current U.S. RF designs. The NARMs modeled with the best performance are R-32/-152a, R-32/-142b, and R-22/-142b. An 18 percent improvement can be expected from the dual-circuit system using R-12 alone, and an additional 6 percent improvement can be gained by replacing R-12 with the selected NARMs in countercurrent heat exchangers. Advantages of the system include greatly reduced energy consumption, easy temperature and humidity control for each compartment, no humidity or odors transferred between compartments, and increased time between defrost cycles. Disadvantages include additional hardware requirements, compressor size, and the difficulties of using a NARM.

Bare, J.C.; Gage, C.L.; Radermacher, R.; Jung, D.S.

1992-01-01

78

Thermodynamic Estimation Method of Ternary Refrigerant Mixtures Using New Mixing Rules  

NASA Astrophysics Data System (ADS)

Binary and ternary refrigerant mixtures are attracting attentions in view of the energy saving and the ozone problem. This paper proposes modified mixing rules of two-constant (a,b) cubic equation of state for ternary mixtures. The addition of the ternary interaction parameter c123 to the mixing rule, occurring in conjunction with the parameter b,was examined in the calculation of thermodynamic properties in comparison with common mixing rules. The validity of new mixing rules was evaluated by using literary vapor-liquid equilibrium date of ternary refrigerant mixtures i. e. R14-R23-R13,R13B1-R12-R152a,R22-R12-R114,R290-R22-R115 and R12-R152a-R113. It was found that the ternary interaction parameter C123 contributes to the accuracy of the vapor pressure and is almost equal irrespective to the measured temperature. The three-dimensional representation system of the phase diagram of ternary refrigerant mixtures was also developed in order to decide compositions of alternative mixtures.

Yoshida, Yuji; Kodama, Hisasi; Funakura, Masami; Arita, Koji

79

Acute Neurobehavioral Effects in Rats from Exposure to HFC 134a or CFC 12  

Microsoft Academic Search

1,1,1,2-Tetrafluoroethane (HFC 134a), a chlorine-free hydrofluoroalkane, is internationally replacing billions of pounds of dichlorodifluoromethane (CFC 12) for coolant, refrigerant and aerosol propellant applications. The ALC50 for HFC 134a in rats is 567,000ppm for 4h; its potential for cardiac epinephrine sensitization in beagle dogs is acceptable (75,000ppm); and its capacity to induce carcinogenicity or developmental disorders in animals is minimal. HFC

Glenn D Ritchie; Edward C Kimmel; Larry E Bowen; James E Reboulet; John Rossi

2001-01-01

80

The Effect of Circuiting Arrangement on the Thermal Performance of Refrigeration Mixtures in Tube-and-Fin Condensing Heat Exchangers  

Microsoft Academic Search

For the pure or azeotropic refrigerants typically used in;\\u000apresent air conditioning and refrigeration applications, the;\\u000arefrigerant changes phase at a constant temperature. Thus, the;\\u000arefrigerant circuiting arrangement such as crossfiow,;\\u000acounterfiow, or cross-counterflow, has no effect on the thermal;\\u000aperformance. For zeotropic refrigerant mixtures, however, the;\\u000aphase-change occurs over a temperature range, or \\

D. T. Chen; J. C. Conklin

1999-01-01

81

NEW CHEMICAL ALTERNATIVE FOR OZONE-DEPLETING SUBSTANCES: HFC-236FA  

EPA Science Inventory

The report gives results of a preliminary evaluation of a new hydrofluorocarbon (HFC)--HFC-236fa or 1,1,1,3,3,3-hexafluoropropane--as a possible alternative for chlorofluorocarbon (CFC)-114 (1,2-dichloro-1,1,2,2-tetrafluoroethane) refrigerant for chillers and as a possible fire s...

82

Energy and exergy analysis of new refrigerant mixtures in an Organic Rankine Cycle for low temperature power generation  

Microsoft Academic Search

This paper presents and discusses the performance of environmentally-friendly refrigerant mixtures in an Organic Rankine Cycle (ORC) for power generation. The performance has been compared at low and medium waste heat temperatures to other organic and non-organic fluids.The refrigerant mixtures boil at extremely low temperatures and are capable of efficiently capturing waste heat at temperatures less than 27°C (80°F). The

S. M. Sami

2010-01-01

83

Evaluation of HFC 245ca and HFC 236ea as foam blowing agents  

NASA Technical Reports Server (NTRS)

Hydrochlorofluorocarbon (HCFC) 141b has been selected as the interim blowing agent for use in urethane insulations on NASA's Space Shuttle External Tank. Due to the expected limited commercial lifetime of this material, research efforts at the NASA Thermal Protection Systems Materials Research Laboratory at the Marshall Space Flight Center are now being devoted to the identification and development of alternatives with zero ozone depletion potential. Physical blowing agents identified to date have included hydrocarbons, fluorocarbons, hydrofluoroethers, and more predominantly, hydrofluorocarbons (HFCs). The majority of the HFC evaluations in industry have focused on the more readily available, low boiling candidates such as HFC 134a. Higher boiling HFC candidates that could be handled at ambient conditions and use current processing equipment would be more desirable. This paper will describe results from a research program of two such candidate HFC's performed as a cooperative effort between Martin Marietta Manned Space Systems, the U.S. Environmental Protection Agency, and Oak Ridge National Laboratories. The purpose of this effort was to perform a cursory evaluation of the developmental HFC's 245ca and 236ea as blowing agents in urethane based insulations. These two materials were selected from screening tests of 37 C2, C3, and C4 isomers based on physical properties, atmospheric lifetime, flammability, estimated toxicity, difficulty of synthesis, suitability for dual use as a refrigerant, and other factors. Solubility of the two materials in typical foam components was tested, pour foaming trials were performed, and preliminary data were gathered regarding foam insulation performance.

Sharpe, Jon; Macarthur, Doug; Kollie, Tom; Graves, Ron; Liu, Matthew; Hendriks, Robert V.

1995-01-01

84

Thermodynamic performance limit and evaporator design considerations for NARM-based domestic refrigerator-freeze systems. Rept. for Aug 89-May 90. [Non-Azeotropic Refrigerant Mixtures  

SciTech Connect

The paper gives results of an investigation of non-azeotropic refrigerant mixtures (NARMs) for a two-temperature-level heat exchange process found in a domestic refrigerator-freezer. Ideal (constant air temperature) heat exchange processes are assumed. The results allow the effects of intercooling between the evaporator refrigerant stream and the condenser outlet stream to be examined systematically. Three refrigerant pairs, R22/R142b, R22/R123, and R32/R142b, were studied, but the results for only R22/R123 are presented because of its unique temperature glide curvature. Practical implementation of a Lorenz cycle constrains evaporator design. An evaporator module design is presented which meets the NARM system constraints.

Smith, M.K.; Heun, M.C.; Crawford, R.R.; Newell, T.A.

1990-01-01

85

Horizontal-flow boiling heat transfer using refrigerant mixtures: Final report  

SciTech Connect

Mixture effects were studied on horizontal convective heat transfer for both nonazeotropic, R22/R114, and azeotropic, R12/R152a, mixtures. A test facility was designed, constructed, and operated to simulate evaporators in heat pump and refrigeration systems. More than 3000 local two-phase heat transfer coefficients were obtained under steady state condition for annular flow at a reduced pressure of 0.08. The results indicated that there were two distant heat transfer regions; partial boiling and convective evaporation. In the partial boiling region, heat transfer coefficients were strongly dependent upon heat flux; the heat flux dependence disappeared for high vapor qualities. A full suppression of nucleate boiling was observed for both pure and mixed refrigerants. For a given heat and mass flux, nucleate boiling was suppressed at lower qualities for mixtures than for pure fluids. The unique phenomenon of loss of available superheat for mixtures caused nucleate boiling to be suppressed at lower qualities. An analytical study was performed to predict the transition quality by utilizing a theory of onset of nuclear boiling and phase equilibrium data. The prediction agreed very well with the present data. 77 refs., 62 figs., 14 tabs.

Jung, D.S.; Didion, D.A.

1989-05-01

86

Compatibility of refrigerants and lubricants with motor materials  

SciTech Connect

During this last quarter, evaluations were complete on the motor materials after 500-hr exposures to refrigerants CFC-123, HFC-134a and HCFC-22 at 90{degrees}C. Materials were also evaluated after exposure to nitrogen at 127{degrees}C to determine effect of the thermal exposure. Other exposures were started during this quarter with refrigerants HCFC-124, HFC-125, HFC-143a, HFC-32 and HFC-152a. One 500 hr exposure is set up per week and one is analyzed the same week. This will enable Trane to complete the 500 hour exposures by the end of the year.

Doerr, R.; Kujak, S.

1992-07-23

87

Efficiency of vapor compression heat pumps based on non-azeotropic refrigerant mixtures  

NASA Astrophysics Data System (ADS)

The work presents the results of cycle computation for vapor compression pumps based on ozone-safe mixed refrigerants. Non-azeotropic binary refrugerants R32/R152a (30/70) and R32/R134a (30/70) were considere as working substances. Properties of non-azeotropic refrigerants were calculated according to the additivity method of thermodynamic functions and method of Lemmon and Jacobsen. Deviations in the values of thermophysical properties obtained with two methods have been determined. It is shown that at the use of nonazeotropic mixture R32/R152a (30/70), energy conversion ratio increases by 2.2-3.6 % compared with the results for R32/R134a (30/70) at temperature difference between the processes of boiling and condensation from 28 to 53 °C.

Mezentseva, N. N.

2011-06-01

88

40 CFR Appendix C to Subpart B of... - SAE J2788 Standard for Recovery/Recycle and Recovery/Recycle/Recharging Equipment for HFC-134a...  

Code of Federal Regulations, 2012 CFR

...82 Protection of Environment ENVIRONMENTAL PROTECTION...for the recovery/recycling of HFC-134a that...Refrigerant Recovery/Recycling Equipment 3. Specification...automotive service garage environment and be capable of continuous... 4. Refrigerant Recycling Equipment...

2012-07-01

89

40 CFR Appendix C to Subpart B of... - SAE J2788 Standard for Recovery/Recycle and Recovery/Recycle/Recharging Equipment for HFC-134a...  

Code of Federal Regulations, 2013 CFR

...82 Protection of Environment ENVIRONMENTAL PROTECTION...for the recovery/recycling of HFC-134a that...Refrigerant Recovery/Recycling Equipment 3. Specification...automotive service garage environment and be capable of continuous... 4. Refrigerant Recycling Equipment...

2013-07-01

90

40 CFR Appendix C to Subpart B of... - SAE J2788 Standard for Recovery/Recycle and Recovery/Recycle/Recharging Equipment for HFC-134a...  

...82 Protection of Environment ENVIRONMENTAL PROTECTION...for the recovery/recycling of HFC-134a that...Refrigerant Recovery/Recycling Equipment 3. Specification...automotive service garage environment and be capable of continuous... 4. Refrigerant Recycling Equipment...

2014-07-01

91

Thermal conductivity of HFC-32, HFC-125, and HFC-134a in the solid phase  

SciTech Connect

Measurements of the thermal conductivity of HFC-32, HFC-125, and HFC-134a were carried out for the first time in both solid and liquid phases at the saturation pressure at room temperature and in the temperature ranges from 120 to 263, from 140 to 213, and from 130 to 295 K, respectively. A transient hot-wire instrument using one bare platinum wire was employed for measurements, with an uncertainty of less than {+-}2%. The experimental results demonstrated that the thermal conductivity of HFC-32, HFC-125, and HFC-134a in the solid phase showed a positive temperature dependence. For HFC-32 and HFC-125, there were big jumps between the solid and the liquid thermal conductivity at the melting point. But for HFC-134a, the solid and liquid thermal conductivity at the melting point is almost-continuous.

Gao, X.; Nagasaka, Y.; Nagashima, A. [Keio Univ., Yokohama (Japan). Dept. of Mechanical Engineering] [Keio Univ., Yokohama (Japan). Dept. of Mechanical Engineering

1998-03-01

92

Evaluation of performance and composition shift of zeotropic mixtures in a Lorenz-Meutzner refrigerator/freezer  

SciTech Connect

Results from previous testing of this refrigerator/freezer using a 750 Btu/h compressor and several zeotropic mixtures revealed a performance enhancement up to 16% above that of hydrofluorocarbon R-134a. In the study presented in this paper, the Lorenz-Meutzner (LM) refrigerator/freezer equipped with a 1060 Btu/h compressor, two evaporators, and two intercoolers was experimentally tested in an environmental chamber according to the Association of Home Appliance Manufacturers/Department of Energy (AHAM/DOE) testing standards using several hydrofluoropropane-based zeotropic mixtures. The results are compared to baseline testing with R-134a and results obtained using the 750 Btu/h compressor. Hydrofluorocarbons R-245ca/R-152a performed comparably to R-134a. R-245ca/hydrocarbon R-270 (cyclopropane C{sub 3}H{sub 6}) outperformed all zeotropic mixtures and R-134a by at least 12.2 {+-} 0.7%. All refrigerants performed better using the larger compressor due to its inherently better efficiency. Refrigerant samples taken during refrigerator/freezer operation revealed substantial composition shifts (e.g., a 30% running composition shift of R-134a in the R-245ca/R-134a mixture). Sand et al. (1993) obtained an approximately 20% energy reduction using steady-state on-cycle energy consumption results; a comparison was made between chlorofluorocarbon R-12 and a hydrofluorocarbon R-32/hydrochlorofluorocarbon R-124 mixture. Lorenz and Meutzner (1975), originators of the Lorenz-Meutzner refrigerator/freezer design, state that the following parameters influence the optimum performance of the design: (1) heat exchanger size, (2) capillary tube length, (3) refrigerant charge, and (4) compressor size. This work investigates three of these parameters--capillary tube length, compressor size, and refrigerant charge.

Baskin, E.; Smith, N.D.; Delafield, F.R.; Tufts, M.W.

1999-07-01

93

Experimental investigation of moderately high temperature water source heat pump with non-azeotropic refrigerant mixtures  

Microsoft Academic Search

Experimental investigations were carried out on non-azeotropic refrigerant mixtures, named M1A (mass fraction of 20%R152a and 80%R245fa), M1B (mass fraction of 37% R152a and 63%R245fa) and M1C (mass fraction of 50%R152a and 50%R245fa), based on a water-to-water heat pump system in the condensing temperature range of 70–90°C with a cycle temperature lift of 45°C. Performance of R245fa was tested for

Shengjun Zhang; Huaixin Wang; Tao Guo

2010-01-01

94

Performance optimization of a Lorenz–Meutzner cycle charged with hydrocarbon mixtures for a domestic refrigerator-freezer  

Microsoft Academic Search

A Lorenz–Meutzner cycle (called the “LM cycle”) for a domestic refrigerator-freezer (RF) has energy saving potential because of lower entropy generation in the fresh food compartment (R)-evaporator and lower compression ratio due to higher mean evaporating temperature, compared to a conventional cycle using pure refrigerant. In this study, a thermodynamic analysis for the optimum compositions of hydrocarbon (HC) mixtures and

Won Jae Yoon; Kookjeong Seo; Hyun Joon Chung; Eun-Ji Lee; Yongchan Kim

95

Thermal conductivity of alternative refrigerants in the liquid phase  

SciTech Connect

Measurements of the thermal conductivity of five alternative refrigerants, namely, difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,1-trifluorethane (HFC-143a), and dichloropentafluoropropanes (HCFC-225ca and HCFC-225cb), are carried out in the liquid phase. The range of temperature is 253-324 K for HFC-32, 257-305 K for HFC-125, 268-314 K for HFC-134a, 267-325 K for HCF-225ca, and 286-345 K for HCFC-225cb. The pressure range is from saturation to 30 MPa. The reproducibility of the data is better than 0.5%, and the accuracy of the data is estimated to be of the order of 1%. The experimental results for the thermal conductivity of each substance are correlated by an equation which is a function of temperature and pressure. A short discussion is given to the comparison of the present results with literature values for HFC-125. The saturated liquid thermal conductivity values of HFC-32, HFC-125, and HFC-143a are compared with those of chlorodifluoromethane (HCFC-22) and tetrafluoroethane (HFC-134a) and it is shown that the value of HFC-32 is highest, while that of HFC-125 is lowest, among these substances. The dependence of thermal conductivity on number of fluorine atoms among the refrigerants with the same number of carbon and hydrogen atoms is discussed.

Yata, J.; Hori, M. [Kyoto Inst. of Technology (Japan); Kobayashi, K. [Kobe Steel Co., Ltd. (Japan); Minamiyama, T. [Fukyuama Univ. (Japan)

1996-05-01

96

Accelerated test methods for predicting the life of motor materials exposed to refrigerant/lubricant mixtures. Phase 1, Conceptual design: Final report  

SciTech Connect

The federally mandated phase-out of chlorofluorocarbon refrigerants requires screening tests for motor materials compatibility with alternative refrigerant/lubricant mixtures. In the current phase of the program, ARTI is supporting tests of promising candidate refrigeration/lubricant systems in key refrigeration component systems such as bearings and hermetic motor insulation systems to screen for more subtle detrimental effects and allow estimates of motor-compressor life. This report covers: mechanisms of failure of hermetic motor insulation, current methods for estimation of life of hermetic motors, and conceptual design of improved stator simulator device for testing of alternative refrigerant/lubricant mixtures.

Ellis, P.F. II; Ferguson, A.

1993-08-18

97

Refrigerator  

SciTech Connect

A refrigerator is described comprising: (a) a housing having a vent compartment and an insulated box having a cooler compartment and a freezer compartment; (b) a thermoelectric heat pump means mounted in the housing, the heat pump means including a finned heat sink of high temperature coefficient material mounted in the vent compartment. A hot plate is attached to the heat sink. A thermopile has a hot side connected to the hot plate and a cold side, a block of high temperature coefficient material is connected to the cold side. An L-shaped bracket of high temperature coefficient material having a vertical portion attached to the block and a horizontal portion extends into the freezer compartment. A freezer compartment of high temperature coefficient material has a bottom attached to the L-shaped horizontal portion. The bottom portion has walls forming an ice cube tray receiving recess whereby the continuous structure of high temperature coefficient material exists between the thermopile and ice cube tray receiving recess to produce a sub freezing temperature in the recess; and (c) an ice cube tray having a shape corresponding to that of the ice cube tray receiving recess whereby five sides of the ice cube tray are in freezing engagement with the bottom recess forming walls for freezing ice cubes.

Burke, E.J.

1987-02-24

98

Performance of mixture refrigerant R152a\\/R125\\/R32 in domestic air-conditioner  

Microsoft Academic Search

This work reports a ternary blend R152a\\/R125\\/R32 with a mass ratio of 48\\/18\\/34 as a potential alternative to R22. A computer code has been developed with NIST REFPROP 7.0 for the comparative analysis of thermophysical properties and refrigerant performance of this new mixture and of R22. A drop-in test of this new mixture was performed in a domestic air-conditioner originally

Jiangtao Wu; Yingjie Chu; Jing Hu; Zhigang Liu

2009-01-01

99

(Discussion of domestic refrigerator/freezer (R/F) design for nonazeotropic refrigerant mixtures (NARMs), Hannover, W. Germany, and visit to Kassel, W. Germany, May 2--5, 1989): Foreign trip report  

SciTech Connect

The purpose of this trip was to meet with Dr. H. Kruse at the University of Hannover and discuss a domestic refrigerator/freezer (R/F) design for nonazeotropic refrigerant mixtures (NARMs), inspect a R/F modified to work with NARMs, and acquire the rational and computer codes for modeling NARM R/F performance for this design.

Sand, J.R.; Vineyard, E.A.

1989-05-18

100

Compatibility of refrigerants and lubricants with motor materials. Quarterly technical progress report, April 1, 1992--June 30, 1992  

SciTech Connect

During this last quarter, evaluations were complete on the motor materials after 500-hr exposures to refrigerants CFC-123, HFC-134a and HCFC-22 at 90{degrees}C. Materials were also evaluated after exposure to nitrogen at 127{degrees}C to determine effect of the thermal exposure. Other exposures were started during this quarter with refrigerants HCFC-124, HFC-125, HFC-143a, HFC-32 and HFC-152a. One 500 hr exposure is set up per week and one is analyzed the same week. This will enable Trane to complete the 500 hour exposures by the end of the year.

Doerr, R.; Kujak, S.

1992-07-23

101

HEAT TRANSFER EVALUATION OF HFC-236EA AND CFC-114 IN CONDENSATION AND EVAPORATION  

EPA Science Inventory

The report gives results of a heat transfer evaluation of the refrigerants hexafluoropropane (HFC-236ea) and 1,1,2,2-dichloro-tetrafluoroethane (CFC-114). (NOTE: With the mandatory phase-out of chlorofluorocarbons (CFCs), as dictated by the Montreal Protocol and Clean Air Act Ame...

102

NEW CHEMICAL ALTERNATIVE FOR OZONE-DEPLETING SUBSTANCES: HFC-236EA  

EPA Science Inventory

The report gives results of a preliminary evaluation of a new hydrofluorocarbon (HFC-236ea or 1, 1, 1, 2, 3, 3-hexafluoropropane) as a possible alternative for chlorofluorocarbon (CFC)-114 (1, 2-dichloro-1, 1, 2, 2-tetrafluoroethane) refrigerant in chillers and high-temperature i...

103

RETROFITTING AN AUTOMOTIVE AIR CONDITIONER WITH HFC-134A, ADDITIVE, AND MINERAL OIL  

EPA Science Inventory

The paper gives results of an evaluation of a lubricant additive developed for use in retrofitting motor vehicle air conditioners. he additive was designed to enable HFC-134a to be used as a retrofit refrigerant with the existing mineral oil in CVC-12 systems. he goal of the proj...

104

Two-Phase Flow of HCFC-22 and HFC-134a through Short Tube Orifices  

E-print Network

HCFC-22 and HFC-134a were used with short tube orifices having length to diameter ratios ranging from 5 to 20 in a 9.53 mm (3/8 in.) refrigerant line to investigate both two-phase and subcooled liquid flow entering the short tubes. Flow temperature...

Yongchan, K.

2008-01-23

105

Emissions and environmental impacts from air-conditioning and refrigeration systems  

Microsoft Academic Search

The impacts of air conditioning and refrigeration systems on stratospheric ozone are primarily linked to release of ozone-depleting refrigerants. Their contributions to global warming stem both from release of refrigerants and from emission of greenhouse gases (GHGs) for associated energy use. Because the energy-related component has a significantly higher warming impact, phaseout of hydrofluorocarbon (HFC) refrigerants with less efficient options

James M. Calm

2002-01-01

106

Performance of environmentally friendly CFC12 replacements for refrigerator\\/freezers  

Microsoft Academic Search

The paper presents the capacity and energy consumption of refrigerant replacements for HFC-134a and\\/or CFC-12 as determined by experimental testing and analysis. Refrigerator\\/freezer (R\\/F) tests were run according to the Association of Home Appliance Manufacturer`s testing conditions in an environmental test chamber. The charge was optimized for each refrigerant, and the results were compared to those for HFC-134a and CFC-12.

E. Baskin; E. S. Bayoglu; F. R. Delafield

1995-01-01

107

Properties and Cycle Performance of Refrigerant Blends Operating Near and Above the Refrigerant Critical Point, Task 1: Refrigerant Properties  

SciTech Connect

The main goal of this project was to investigate and compare the performance of an R410A air conditioner to that of an R22 air conditioner, with specific interest in performance at high ambient temperatures at which the condenser of the R410A system may be operating above the refrigerant's critical point. Part 1 of this project consisted of measuring thermodynamic properties R125, R410A and R507A, measuring viscosity and thermal conductivity of R410A and R507A and comparing data to mixture models in NIST REFPROP database. For R125, isochoric (constant volume) heat capacity was measured over a temperature range of 305 to 397 K (32 to 124 C) at pressures up to 20 MPa. For R410A, isochoric heat capacity was measured along 8 isochores with a temperature range of 303 to 397 K (30 to 124 C) at pressures up to 18 MPa. Pressure-density-temperature was also measured along 14 isochores over a temperature range of 200 to 400 K (-73 to 127 C) at pressures up to 35 MPa and thermal conductivity along 6 isotherms over a temperature range of 301 to 404 K (28 to 131 C) with pressures to 38 MPa. For R507A, viscosity was measured along 5 isotherms over a temperature range of 301 to 421 K (28 to 148 C) at pressures up to 83 MPa and thermal conductivity along 6 isotherms over a temperature range of 301 to 404 K (28 to 131 C) with pressures to 38 MPa. Mixture models were developed to calculate the thermodynamic properties of HFC refrigerant mixtures containing R32, R125, R134a and/or R125. The form of the model is the same for all the blends considered, but blend-specific mixing functions are required for the blends R32/125 (R410 blends) and R32/134a (a constituent binary of R407 blends). The systems R125/134a, R125/143a, R134a/143a, and R134a/152a share a common, generalized mixing function. The new equation of state for R125 is believed to be the most accurate and comprehensive formulation of the properties for that fluid. Likewise, the mixture model developed in this work is the latest state-of-the-art for thermodynamic properties of HFC refrigerant blends. These models were incorporated into version 7 of NIST REFPROP database.

Mark O. McLinden; Arno Laesecke; Eric W. Lemmon; Joseph W. Magee; Richard A. Perkins

2002-08-30

108

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

SciTech Connect

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 refrigerants 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.

Fricke, Brian A [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL; Vineyard, Edward Allan [ORNL] [ORNL

2013-01-01

109

Greenhouse gas emissions for refrigerant choices in room air conditioner units.  

PubMed

In this work, potential replacement refrigerants for window-mounted room air conditioners (RACs) in the U.S. have been evaluated using a greenhouse gas (GHG) emissions analysis. CO(2)-equivalent emissions for several hydrofluoroethers (HFEs) and other potential replacements were compared to the most widely used refrigerants today. Included in this comparison are pure refrigerants that make up a number of hydrofluorocarbon (HFC) mixtures, pure hydrocarbons, and historically used refrigerants such as propane and ammonia. GHG emissions from direct and indirect sources were considered in this thermodynamic analysis. Propylene, dimethyl ether, ammonia, R-152a, propane, and HFE-152a all performed effectively in a 1 ton window unit and produced slightly lower emissions than the currently used R-22 and R-134a. The results suggest that regulation of HFCs in this application would have some effect on reducing emissions since end-of-life emissions remain at 55% of total refrigerant charge despite EPA regulations that mandate 80% recovery. Even so, offsite emissions due to energy generation dominate over direct GHG emissions and all the refrigerants perform similarly in totals of indirect GHG emissions. PMID:23136858

Galka, Michael D; Lownsbury, James M; Blowers, Paul

2012-12-01

110

Performance of A Vapour Compression Heat Pump System Using A Nonazeotropic Refrigerant Mixture  

NASA Astrophysics Data System (ADS)

An experimental study of the performance of a vapour compression heat pump system using a HCFC22 and CFC114 mixture of 20, 40, 60 and 100 mass% of HCFC22 as a working fluid was carried out. Heat Transfer characteristics of the condenser and the evaporator were also investigated. The condenser and the evaporator were counter flow heat exchangers with a smooth copper tube of 12 mmID and 8 m length. The experiments were performed under the conditions that the flow rates of the heat source and sink water and their inlet temperatures of the heat exchangers were kept constant, maintaining the constant evaporating temperature at the inlet of the evaporater. The results indicate that the coefficients of performance (COP) in case of the mixtures are about 45% higher than that of pure HCFC22 in the range of CFC1l4 mass fraction from 0.6 to 0.8 and the effect of the composition of mixtures on COP is well agreement with that obtained from the thermodynamic cycle analysis. Overall heat transfer coefficient of mixtures decreases with increasing CFC114 mass fraction of the mixture and the empirical correlation for the effect of the composion of the mixture on condensation heat transfer is obtained.

Goto, Masao; Kanbe, Kouji; Sakai, Takanori; Inoue, Norihiro

111

Proceedings of the 1993 non-fluorocarbon insulation, refrigeration and air conditioning technology workshop  

SciTech Connect

Sessions included: HFC blown polyurethanes, carbon dioxide blown foam and extruded polystyrenes, plastic foam insulations, evacuated panel insulation, refrigeration and air conditioning, absorption and adsorption and stirling cycle refrigeration, innovative cooling technologies, and natural refrigerants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

Not Available

1994-09-01

112

Proceedings of the 1993 Non-Fluorocarbon Insulation, Refrigeration and Air Conditioning Technology Workshop  

NASA Astrophysics Data System (ADS)

Sessions included: HFC blown polyurethanes, carbon dioxide blown foam and extruded polystyrenes, plastic foam insulations, evacuated panel insulation, refrigeration and air conditioning, absorption and adsorption and stirling cycle refrigeration, innovative cooling technologies, and natural refrigerants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

113

Evaluation of HFC-245ca for commercial use in low pressure chillers. Final report, Volume I  

SciTech Connect

Federal regulations banned the production of CFC-11 on January 1, 1996. HCFC-123, the only commercial alternative, will be limited to service applications after January 1, 2020 and will be eliminated from production on January 1, 2030. HFC-245ca has been identified as a potential replacement for CFC-11 in retrofit applications and for HCFC-123 in new chillers, but the marginal flammability of HFC-245ca is a major obstacle to its commercial use as a refrigerant in the United States. This report assesses the commercial viability of HFC-245ca based on its experimental performance in a direct drive low pressure centrifugal chiller exclusive of its flammability characteristics. Three different impeller diameters were tested in the chiller, with all impellers having identical discharge blade angles. Experimental work included tests in a 200 ton 3 stage direct drive chiller with 3 impeller sets properly sized for each of three refrigerants, CFC-11, HCFC-123, and HFC-245ca. The commercial viability assessment focused on both retrofit and new product performance and cost.

Keuper, E.F. [Trane Co., LaCrosse, WI (United States)] [Trane Co., LaCrosse, WI (United States)

1996-03-01

114

Positive Displacement Compressor Technology for Refrigeration  

NASA Astrophysics Data System (ADS)

Trends of compressor technologies for refrigerators, freezers and condensing units are presented in this paper. HFC refrigerants such as R134a and R404C are promising candidates as an altemative for R12. Performance of reciprocating and rotary compressors in the operation with R134A is described. In addition, compressor technologies such as efficiency improvement are described in the cases of reciprocating, rotary and scroll compressors.

Nagatomo, Shigemi

115

Performance of a conventional residential-sized heat pump operating with a nonazeotropic binary refrigerant mixture  

SciTech Connect

The report presents laboratory-performance measurements of a relatively unmodified residential heat pump designed for R22 when charged with a nonazeotropic, binary mixture of R13B1 and R152a. Results are presented for various sizes of fixed-expansion devices. The effect of gliding temperature within the saturation zone was found to be small. The experimental investigation confirmed that flash distillation within the accumulator would improve low-temperature heating performance. The measured performance was approximately 11% lower in both efficiency and capacity than R22 for air conditioning. The high-temperature heating efficiency was 3% lower than R22. The low-temperature heating capacity was 14% higher and efficiency 2% higher than R22. These results show a substantial improvement over R22 for heating applications at the expense of reduced cooling-mode performance. Further performance enhancement for this or other mixtures is expected through various system modifications that remain to be studied.

Mulroy, W.; Didion, D.

1986-10-01

116

Thermodynamic and transport properties of some alternative ozone-safe refrigerants for industrial refrigeration equipment: Study in Belarus and Ukraine  

NASA Astrophysics Data System (ADS)

The study of several hydrofluorocarbons (HFC) and fluorocarbons (FC) and their binary mixtures that have no ozone-depleting ability is being carried Out in the framework of Belarus National Program. The fluids include HFCs R134a. R152a, R135, and R32, and FC R218. The following properties are being investigated: ( I ) phase equilibrium parameters including the boiling and condensing curve and critical point, thermophysical properties at these parameters, and heat of evaporation: (2) isobaric and isochoric heat capacity, ethalpy, and entropy in the gas and liquid state: (3) speed of sound, thermal conductivity. viscosity, and density in the gas and liquid state: (4) dielectric properties and surface tension: (5) behavior of combined construction materials inside the refrigerant medium: and (6) solubility in compressor oils and other technological characteristics. The series of results obtained by authors during the period 1990 1993 is presented.

Grebenkov, A. J.; Zhelezny, V. P.; Klepatsky, P. M.; Beljajeva, O. V.; Chernjak, Yu. A.; Kotelevsky, Yu. G.; Timofejev, B. D.

1996-05-01

117

Thermodynamic and transport properties of some alternative ozone-safe refrigerants for industrial refrigeration equipment: Study in Belarus and Ukraine  

SciTech Connect

The study of several hydrofluorocarbons (HFC) and fluorocarbons (FC) and their binary mixtures that have no ozone-depleting ability is being carried out in the framework of Belarus National program. The fluids include HFCs R134a, R152a, R125, and R32, and FC R218. The following properties are being investigated: (1) phase equilibrium parameters including the boiling and condensing curve and critical point, thermophysical properties at these parameters, and heat of evaporation; (2) isobaric and isochoric heat capacity, ethalpy, and entropy in the gas and liquid state; (3) speed of sound, thermal conductivity, viscosity, and density in the gas and liquid state; (4) dielectric properties and surface tension; (5) behavior of combined construction materials inside the refrigerant medium; and (6) solubility in compressor oils and other technological characteristics. The series of results obtained by authors during the period 1990-1993 is presented.

Grebenkov, A.J.; Klepatsky, P.M.; Beljajeva, O.V. [Inst. of Power Engineering Problems, Minsk (Belgium)] [and others

1996-05-01

118

The performance of a residential heat pump operating with a nonazeotropic binary refrigerant mixture  

NASA Astrophysics Data System (ADS)

Results of laboratory measurement of the performance change of a substantially unmodified residential heat pump designed for 222 when charged with a non azeotropic, binary mixture of R1381 and R152a is presented. Results are presented for various sizes of fixed expansion devices. The effect of gliding temperature in the saturation zone was found to be small. The effect of compositions shift by flash distillation in the accumulator was found to measurably improve low temperature heating performance. It was further observed that some system modification (such as the addition of a receiver) could have further enhanced this low temperature heating performance improvement.

Didion, D.; Mulroy, W.

119

Study of the Vapor-Liquid Coexistence Curve and the Critical Curve for Nonazeotropic Refrigerant Mixture R152a + R114 System  

NASA Astrophysics Data System (ADS)

Measurements of the vapor-liquid coexistence curve in the critical region for the refrigerant mixture of R152a (CH3CHF2: 1, l-difluoroethane) +R 114 (CCIF2CCIF2 :1, 2-dichloro-1, 1, 2, 2-tetrafluoroethane) system were made by visual observation of the disappearance of the meniscus at the vapor-liquid interface within an optical cell. Forty-eight saturated densities along the vapor-liquid coexistence curve between 204 and 861 kg·m-3 for five different compositions of 10, 20, 50, 80 and 90 wt% R 152a were obtained in the temperature range 370 to 409 K. The experimental errors of temperature, density, and mass fraction were estimated within ±10mK, ±0.5% and +0.05 %, respectively. On the basis of these measurements, the critical parameters of five different compositions for the R 152a +R 114 system were determined in consideration of the meniscus disappearance level as well as intensity of the critical opalescence. In accordance with the previous results of three other refrigerant mixtures, i.e., R 12 +R 22 system, R 22 +R 114 system and R 13B1 + R 114 system, the coexistence curve and critical curve on the temperature-density diagram for binary refrigerant mixtures were discussed. In addition, correlations of its composition dependence for this system were proposed.

Kabata, Yasuo; Higashi, Yukihiro; Uematsu, Masahiko; Watanabe, Koichi

120

A Vapor-Liquid Equilibria Model for Hydrofluorocarbons and Their Binary Mixtures  

NASA Astrophysics Data System (ADS)

A novel thermodynamic model has been proposed so as to calculate the thermodynamic properties at the vapor-liquid coexistence of HFC (hydrofluorocarbon) refrigerants and their binary mixtures. This model has been developed by modifying the Patel-Teja equation, well-known cubic equation of state, for HFC refrigerants, R- 32, R-125, R-134a, and their binary mixtures for temperatures from 220 K to their critical temperatures. The developed model has features in calculating various thermodynamic properties with ease but accurately. The calculated results on the vapor-liquid equilibrium (VLE) properties by the present model illustrate its superiority to the conventional cubic equations of state. A comparison of the proposed model with the so-called modified Benedict-Webb-Rubin (MBWR) model and the multi-term Helmholtz function model confirms equivalent effectiveness and accuracy by the present model and, therefore, it would be concluded that the proposed model is very powerful in various practical application in refrigeration industry.

Li, Jin; Sato, Haruki; Yokozeki, Akimichi; Watanabe, Koichi

121

ZnO nanorefrigerant in R152a refrigeration system for energy conservation and green environment  

NASA Astrophysics Data System (ADS)

In this paper the reliability and performance of a vapour compression refrigeration system with ZnO nanoparticles in the working fluid was investigated experimentally. Nanorefrigerant was synthesized on the basis of the concept of the nanofluids, which was prepared by mixing ZnO nanoparticles with R152a refrigerant. The conventional refrigerant R134a has a global warming potential (GWP) of 1300 whereas R152a has a significant reduced value of GWP of 140 only. An experimental test rig is designed and fabricated indigenously in the laboratory to carry out the investigations. ZnO nanoparticles with refrigerant mixture were used in HFC R152a refrigeration system. The system performance with nanoparticles was then investigated. The concentration of nano ZnO ranges in the order of 0.1% v, 0.3% v and 0.5%v with particle size of 50 nm and 150 g of R152a was charged and tests were conducted. The compressor suction pressure, discharge pressure and evaporator temperature were measured. The results indicated that ZnO nanorefrigerant works normally and safely in the system. The ZnO nanoparticle concentration is an important factor considered for heat transfer enhancement in the refrigeration system. The performance of the system was significantly improved with 21% less energy consumption when 0.5%v ZnO-R152a refrigerant. Both the suction pressure and discharge pressure were lowered by 10.5% when nanorefrigerant was used. The evaporator temperature was reduced by 6% with the use of nanorefrigerant. Hence ZnO nanoparticles could be used in refrigeration system to considerably reduce energy consumption. The usage of R152a with zero ozone depleting potential (ODP) and very less GWP and thus provides a green and clean environment. The complete experimental results and their analysis are reported in the main paper.

Sendil Kumar, D.; Elansezhian, R.

2014-03-01

122

Performance testing of a semi-hermetic compressor with HFC-236EA and CFC-114 at chiller conditions. Report for December 1993-May 1994  

SciTech Connect

The paper gives results of tests of both HFC-236ea and CFC-114 at a range of temperatures covering surface craft and submarine chiller conditions. Evaporating temperatures ranged from 1.7 to 12.8 C, and condensing temperatures from 40.6 to 65.6 C, in order to develop a nine-point test map. Polyol ester oil was used with the refrigerants. The tests evaluated suction and discharge pressures, their difference and ratio, cooling capacity, electric power input, compressor energy efficiency ratio (coefficient of performance), electric current, and compressor volumetric and isentropic energy efficiency. Compressor discharge, motor winding, and oil temperature were also monitored. HFC-236ea is one of the strongest candidates for a CFC-114 alternative in surface craft and submarine chillers. Some material compatibility and oil miscibility work has also been performed in support of HFC-236ea as a refrigerant.

Kazachki, G.S.; Hendriks, R.V.

1994-12-31

123

Thermal conductivity and PVT measurements of pentafluoroethane (refrigerant HFC-125)  

SciTech Connect

By means of the transient and steady-state coaxial cylinder methods, the thermal conductivity of pentfluoroethane was investigated at temperatures from 187 to 419 K and pressures from atmospheric to 6.0 MPa. The estimated uncertainty of the measured results is {+-} (2-3)%. The operation of the experimental apparatus was validated by measuring the thermal conductivity of R22 and R12. Determinations of the vapor pressure and PVT properties were carried out by a constant-volume apparatus for the temperature range 263 to 443 K, pressures up to 6 MPa, and densities from 36 to 516 kg m{sub -3}. The uncertainties in temperature, pressure, and density are less than {+-}10 mK, {+-}0.08%, and {+-}0.1%, respectively.

Tsvetkov, O.B.; Kletski, A.V.; Laptev, Yu.A. [Technological Institute of Refrigeration, St. Petersburg (Russian Federation)

1995-09-01

124

Study on the compatibility of insulation materials for hermetic motor under alternative refrigerants and new lubricants atmosphere  

NASA Astrophysics Data System (ADS)

HFC407C and HFC410A were introduced as the alternative refrigerants for HCFC22 in air conditioner to follow the Motreal protocol. But HFCs were also regulated by the Kyoto protocol and natural refrigerants like hydrocarbon (HC) and CO2 are researched and introduced in the market. Under these circumstances the compatibility of motor insulation materials for hermetic motor under alternative refrigerants and lubricants become important. In this paper we discuss the compatibility of magnet wires and films of hermetic motor for air conditioner under atmosphere of HFC407C and HFC410A with POE and PVE lubricants and also discuss it under atmosphere of R600a with mineral oil and CO2 with PAG lubricant in comparison of conventional atmosphere.

Komatsubara, Takeo; Sunaga, Takeshi; Takahashi, Yasuki

125

Thermodynamic Properties for A Drop-in Refrigerant R-SP34E  

NASA Astrophysics Data System (ADS)

Although a transition into several promising HFC alternative refrigerants and their mixtures from conventional CFC and/or HCFC refrigerants is steadily in progress, there still remains a niche to pursue a drop-in refrigerant in some limited engineering applications where the advantage of retrofitting can be emphasized.R-SP34E is one of such drop-in refrigerants to complement R-12 which is a ternary mixture refrigerant consisted of R-134a with minor fractions of propane and ethanol. In this paper, the fundamental thermodynamic properties such as VLE properties and gas-phase PVT properties of R-SP34E are presented. This paper reports the first sets of measured data including 7 dew-and bubble-point pressures and 73 gas-phase PVT properties in the extensive range of temperatures 300-380 K, pressures 0.1-5.2 MPa, and densities up to around the critical density, obtained by employing the Burnett apparatus. In order to complement and confirm the reliability of the measurements, thermodynamic models including a dew-point pressure correlation and a truncated virial equation of state were originally developed in this study. The models were confirmed to exhibit not only excellent reproducibility of the measurements but also the thermodynamic consistency regarding the temperature dependence of the second and third virial coefficients and derived properties such as specific heats or speed of sound. By presenting the reliable thermodynamic model, a systematic information about the thermodynamic properties of R-SP34E is provided in this paper.

Kayukawa, Yohei; Hondo, Takashi; Watanabe, Koichi

126

Atmospheric histories and global emissions of the anthropogenic hydrofluorocarbons HFC-365mfc, HFC-245fa, HFC-227ea, and HFC-236fa  

E-print Network

We report on ground-based atmospheric measurements and emission estimates of the four anthropogenic hydrofluorocarbons (HFCs) HFC-365mfc (CH[subscript 3]CF[subscript 2]CH[subscript 2]CF[subscript 3], 1,1,1,3,3-pentafluorobutane), ...

Rigby, Matthew

127

Laboratory testing of a heat pump system with water-to-water, counterflow heat exchangers using various compositions of an R13B1\\/R152a nonazeotropic refrigerant mixture  

Microsoft Academic Search

Testing was performed with a nonazeotropic refrigerant mixture of R13B1\\/R152a to determine its ability to achieve capacity, relative to R\\/22, at low ambient temperatures. The selection of such a mixture could improve the efficiency of a heat pump by decreasing the cycling losses, which account for approximately 7-12% of the annual energy use, along with decreasing the amount of resistance

Vineyard

1987-01-01

128

Performance of a residential heat pump operating with a non-azeotropic binary refrigerant mixture - an interim report. [R22 vs non-azeotropic binary mixture of R13B1 and R152a  

SciTech Connect

This report presents results of laboratory measurement of the performance change of a substantially unmodified residential heat pump designed for R22 when charged with a non-azeotropic, binary mixture of R13B1 and R152a. Results are presented for various sizes of fixed expansion devices. The effect of gliding temperature in the saturation zone was found to be small. The effect of composition shift by flash distillation in the accumulator was found to measurably improve low temperature heating performance. There appears to be an inherent trade-off when operating an unmodified heat pump with mixtures so as to increase capacity at lower temperatures. This trade-off is that as the evaporator pressure decreases and refrigerant begins to flood through to the accumulator and thus allowing the composition shift to occur, the subcooling on the high pressure side also decreases causing a decrease in the available latent enthalpy difference. A possible solution to this problem might be to increase the amount of initial charge. This would cause on increase in head pressures which could be a problem in the cooling mode. A possible solution to this excessive head pressure problem would be to incorporate a receiver in the system in the branch line just ahead of the expansion device for the outdoor coil. Thus, when this coil is acting as an evaporator (i.e., heating mode) the stored refrigerant would be released into the circulating system allowing for more composition shift to occur. Such a solution will be pursued as one of the items of study during the next phase of this project. 9 refs., 11 figs., 1 tab.

Didion, D.; Mulroy, W.

1984-01-01

129

Pool boiling of enhanced heat transfer surfaces in refrigerant-oil mixtures and aqueous calcium sulfate solutions  

Microsoft Academic Search

Pool boiling data of structured surfaces in R113\\/3GS oil mixtures show a general decrease in heat transfer with oil concentration, degradation in performance of all surfaces at 10% oil, no change in enhancement of the structured surfaces over plain surface, and restoration of performance of the enhanced surfaces upon cleaning in denatured alcohol. Fouling data of structured surfaces in pool

L. A. Curcio; E. F. Somerscales

1994-01-01

130

Alternative refrigerants and refrigeration cycles for domestic refrigerators  

SciTech Connect

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) 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.

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

1992-12-01

131

Malone refrigeration  

SciTech Connect

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.

Swift, G.W.

1993-01-01

132

Energy and global warming impacts of next generation refrigeration and air conditioning technologies  

SciTech Connect

Significant developments have occurred in hydrofluorocarbon (HFC) and the application of ammonia and hydrocarbons as refrigerant working fluids since the original TEWI (Total Equivalent Warming Impact) report in 1991. System operating and performance data on alternative refrigerants and refrigeration technologies justify and updated evaluation of these new alternative refrigerants and competing technologies in well-characterized applications. Analytical and experimental results are used to show quantitative comparisons between HFCS, HFC blends, hydrocarbons, and ammonia, used as refrigerants. An objective evaluation is presented for commercial and near commercial non-CFC refrigerants/blowing agents and alternative refrigeration technologies. This information is needed for objective and quantitative decisions on policies addressing greenhouse gas emissions from refrigeration and air conditioning equipment. The evaluation assesses the energy use and global warming impacts of refrigeration and air conditioning technologies that could be commercialized during the phase out of HCFCS. Quantitative comparison TEWI for two application areas are presented. Opportunities for significant reductions in TEWI are seen with currently known refrigerants through improved maintenance and servicing practices and improved product designs.

Sand, J.R.; Fischer, S.K.; Baxter, V.D.

1996-10-01

133

Thermoacoustic refrigeration  

NASA Technical Reports Server (NTRS)

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.

Garrett, Steven L.; Hofler, Thomas J.

1991-01-01

134

Malone refrigeration  

NASA Astrophysics Data System (ADS)

Malone refrigeration is the use of a liquid near its critical point, without evaporation, as the working fluid in a refrigeration cycle such as the Stirling cycle. We discuss relevant properties of appropriate liquids, and we describe two Malone refrigerators. The first, which was completed several years ago, established the basic principles of use for liquids in such cycles. The second, now under construction, is a linear, free-piston machine.

Swift, G. W.

135

Thermotile Refrigerators  

NASA Technical Reports Server (NTRS)

Thermoelectric tiles provide cooling exactly where needed. Thermotile is modular thermoelectric cooling unit that incorporates sensor and electronic circuitry in addition to thermoelectric device. Refrigerator/freezer is lined with thermotiles clipped into supporting lattices. Small fans used to circulate air in refrigerator and freezer compartments. Elimination of conventional mechanical refrigeration machinery reduces number of moving parts and completely eliminates noise and vibration. Data capabilities of thermotile refrigeration system used for diagnosis of defects or monitoring local temperatures. Thermotiles produced by automated manufacturing techniques. Custom shapes molded as needed.

Park, Brian V.

1994-01-01

136

Adsorption of hydrofluorocarbons HFC134 and HFC134A on X and Y zeolites: Effect of ion-exchange on selectivity and heat of adsorption  

Microsoft Academic Search

Adsorption isotherms and heats of adsorption were measured for HFC-134 (1,1,2,2-tetrafluoroethane) and HFC-134a (1,1,1,2-tetrafluoroethane) on a series of ion-exchanged (H, Li, Na, Rb, Cs) faujasites using volumetric and calorimetric techniques. The species and number of ions present in the zeolite strongly influence the heats of adsorption and the preferential adsorption of HFC-134 compared to HFC-134a. The selectivity is considerably higher

Scott Savitz; Flor R. Siperstein; Robert Huber; Stephen M. Tieri; Raymond J. Gorte; Alan L. Myers; Clare P. Grey; David R. Corbin

1999-01-01

137

Literature survey of heat transfer enhancement techniques in refrigeration applications  

SciTech Connect

A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerant heat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.

Jensen, M.K.; Shome, B. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Mechanical Engineering, Aeronautical Engineering and Mechanics

1994-05-01

138

Global emissions of HFC23 estimated to year 2015  

Microsoft Academic Search

HFC-23 (trifluoromethane, fluoroform, CHF3) is a powerful greenhouse gas that is formed at the reactor stage of the manufacture of HCFC-22 (chlorodifluoromethane, CHClF2). The amount formed depends on the conditions used in the manufacturing process and, for individual plants, lies between 1% and 4% of the production of HCFC-22. While it is possible to reduce the formation of HFC-23 by

A. McCulloch; A. A. Lindley

2007-01-01

139

Heat transfer during condensation of HFC-134a and R-404A inside of a horizontal smooth and micro-fin tube  

SciTech Connect

In recent small and medium capacity refrigeration systems, the condenser tubes are provided with micro-fins from inside. The vapour refrigerant at the compressor outlet and the condenser inlet is in superheat state. As it advances in the condenser it is in two phases and at the outlet it is in sub cooled liquid. The heat transfer coefficient (HTC) during condensation of HFC-134a and R-404A in a smooth (8.56 mm ID) and micro-fin tubes (8.96 mm ID) are experimentally investigated. Different from previous studies, the present experiments are performed for various condensing temperatures, with superheating and sub cooling and using hermetically sealed compressor. The test runs are done at average saturated condensing temperatures ranging from 35 C to 60 C. The mass fluxes are between 90 and 800 kg m{sup -2} s{sup -1}. The experimental results indicate that the average HTC increases with mass flux but decreases with increasing condensing temperature for both smooth and micro-fin tubes. The average condensation HTCs of HFC-134a and R-404A for the micro-fin tubes were 1.5-2.5 and 1.3-2 times larger than that in smooth tube respectively. The HTCs for R-404A are less than that of HFC-134a. New correlations based on the data gathered during the experimentation for predicting condensation HTCs are proposed for wide range of operating conditions. (author)

Sapali, S.N. [Govt. College of Engineering, Department of Mechanical Engineering, Shivaji Nagar, Pune, Maharashtra 411 005 (India); Patil, Pradeep A. [AISSMS College of Engineering, Pune University, Mechanical Engineering Department, Kennedy Road, Near R.T.O., Pune, Maharashtra 411 001 (India)

2010-11-15

140

Thermodynamic properties for the alternative refrigerants  

Microsoft Academic Search

Models commonly used to calculate the thermodynamic properties of refrigerants are summarized. For pure refrigerants, the virial, cubic, Martin-Hou, Benedict-Webb-Rubin, and Helmholtz energy equations of state and the extended corresponding states model are discussed. High-accuracy formulations for 16 refrigerants are recommended. These models may be extended to mixtures through the use of mixing rules applied either to the parameters of

Mark O McLinden; Eric W Lemmon; Richard T Jacobsen

1998-01-01

141

Laboratory testing of a heat pump system with water-to-water, counterflow heat exchangers using various compositions of an R13B1/R152a nonazeotropic refrigerant mixture  

SciTech Connect

Testing was performed with a nonazeotropic refrigerant mixture of R13B1/R152a to determine its ability to achieve capacity, relative to R/22, at low ambient temperatures. The selection of such a mixture could improve the efficiency of a heat pump by decreasing the cycling losses, which account for approximately 7-12% of the annual energy use, along with decreasing the amount of resistance heat required at low ambient temperatures. Results for the mixture show a potential capacity modulation from 12431 Btu/hr (3643 W) at 17 F (-8.3 deg C) to 8550 Btu/hr (2506 W) at 47 F (8.3 deg C) in heating and from 7451 Btu/h (2184 W) at 82 F (27.8 deg C) to 9188 Btu/h (2693 W) at 95 F (35 deg C) in cooling. An analysis of the coefficients of performance for the mixture and its pure components is presented along with a comparison against results obtained with R/22. The comparison is based on maintaining equivalent inlet and exit water temperatures in the evaporator and condenser for both R/22 and the mixtures. 4 refs., 8 figs., 4 tabs.

Vineyard, E.A.

1987-01-01

142

Atmospheric trend and emission estimates for HFC-43-10mee (1999 to 2010)  

NASA Astrophysics Data System (ADS)

We present the first atmospheric measurements of HFC-43-10mee (1,1,1,2,2,3,4,5,5,5-decafluoropentane), an anthropogenic gas introduced in the mid-1990s as a substitute for CFC-113 (1,1,2-trichlorotrifluoroethane). The global warming potential of this HFC (hydrofluorocarbon) has been reported as 1640 (100-year time horizon), hence, its inclusion within a class of chemicals in the Kyoto Protocol and now its consideration for addition in the Montreal Protocol. Commercial HFC-43-10mee is a mixture of two diastereomers; both detectable using the Medusa GC-MS cryogenic trapping system (Miller et al., 2008), and included in our calculations for total HFC-43-10mee concentration. Chen et al. [2010] recently reported that the diastereomers have identical lifetimes in the troposphere of ?18 years. Our northern hemisphere (NH) tropospheric record spans from 1999 to present day, utilizing 12 archive samples together with recent in situ measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE) program at Trinidad Head and La Jolla, California. Precisions of < 0.01 ppt (parts-per-trillion, dry air mole fraction) allow for observation of an accelerated rise from 0.04 ppt in 2000 (growth rate of 0.01 ppt/yr) to 0.10 ppt in 2005 (0.02 ppt/yr) and 0.21 ppt in 2010 (0.03 ppt/yr). From the experimentally defined mole fractions in the background NH, we estimate the growth trend in the southern hemisphere using a simple box model which includes the stratosphere. Further, we estimate ‘top-down’ emissions to the global atmosphere for 2009 at ? 1200 tonnes. ‘Bottom-up’ estimates from the Emission Database for Global Atmospheric Research (EDGAR) v.4.0 only include emissions from Austria and France in 2005, which total 206 tonnes. For comparison, the global emissions in 2005 from our model equate to ? 800 tonnes. Further measurement and modeling efforts are warranted together with projections of future consumption. References: Miller, B. R., R. F. Weiss, P. K. Salameh, T. Tanhua, B. R. Greally, J. Mühle, and P. G. Simmonds (2008), Medusa: A sample preconcentration and GC/MS detector system for in situ measurements of atmospheric trace halocarbons, hydrocarbons and sulfur compounds, Anal. Chem., 80, 1536- 1545. Chen, L., S. Uchimaru, K. Kutsuna, K.Tokuhashi and A. Sekiya (2010), Kinetics study of gas-phase reactions of erythro/threo-CF3CHFCHFC2F5 with OH radicals at 253-328 K, Chem. Phys. Lett., 488, 22-26

Arnold, T.; Ivy, D. J.; Muhle, J.; Harth, C. M.; Salameh, P.; Weiss, R. F.

2010-12-01

143

Recent Refrigeration Cycle Technologies for Household Refrigerators  

NASA Astrophysics Data System (ADS)

The household refrigerator is one of the most important and the biggest energy-consuming home appliances. This paper summarize recent refrigeration cycle developments in the field of domestic household refrigerators based on a survey of publications.

Nagatomo, Shigemi

144

Inventory and mitigation opportunities for HFC-134a emissions from nonprofessional automotive service  

NASA Astrophysics Data System (ADS)

Many vehicle owners in the United States recharge their vehicles' air conditioning systems with small containers of hydrofluorocarbon-134a (HFC-134a, CH2FCF3), at a frequency estimated to be once every year on average. Such nonprofessional service produces immediate emissions of this potent greenhouse gas during service and from the residual heel in partially used containers. The nonprofessional operations are also associated with increased delayed refrigerant emissions that occur because owners are less likely to repair leaks than professional technicians. In California, an estimated 1.3 million nonprofessional service operations performed each year generate 0.27 ± 0.07 million metric ton CO2 equivalent (MMTCO2e) of immediate emissions and 0.54 ± 0.08 MMTCO2e of delayed emissions, using a Global Warming Potential of 1300 for HFC-134a. The immediate emissions can be largely mitigated by a regulation that requires self-sealing valves and improved labeling instructions on the containers, a deposit-return-recycling program for the containers, and a consumer education program. If 95% of the used containers were to be returned by consumers for recycling of the container heel, the annual immediate emissions would be reduced by 0.26 ± 0.07 MMTCO2e. In the United States, an estimated 24 million nonprofessional service operations are performed each year, generating 5.1 ± 1.4 MMTCO2e of immediate emissions and 10.4 ± 1.5 MMTCO2e of delayed emissions. Mitigation measures equivalent to the California regulation would reduce nationwide immediate emissions by 4.9 ± 1.4 MMTCO2e, if 95% of the used cans were returned for recycling. These business-as-usual emissions and mitigation potentials are projected to stay approximately constant until around 2022, and remain at significant levels into the 2030s.

Zhan, Tao; Potts, Winston; Collins, John F.; Austin, Jeff

2014-12-01

145

Thermoelectric refrigerator  

NASA Technical Reports Server (NTRS)

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.

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

146

Atmospheric lifetime and global warming potential of HFC245fa  

Microsoft Academic Search

We describe the method used to compute the global warming potential of hydrofluorocarbon (HFC) 245fa (CHF2CH2CF3). The Atmospheric and Environmental Research (AER) two-dimensional (latitude-height) chemistry-transport model was used to calculate the atmospheric lifetime and atmospheric scale height of HFC-245fa. Assuming that reaction with OH is the only removal mechanism, the recommended rate constant from Jet Propulsion Laboratory [1997] (6.1×10-13exp(-1330\\/T)cm-3s-1) implies

Malcolm Ko; Run-Lie Shia; Nien-Dak Sze; Hillel Magid; Robert G. Bray

1999-01-01

147

Properties and Cycle Performance of Refrigerant Blends Operating Near and Above the Refrigerant Critical Point, Task 2: Air Conditioner System Study  

SciTech Connect

The main goal of this project was to investigate and compare the performance of an R410A air conditioner to that of an R22 air conditioner, with specific interest in performance at high ambient temperatures at which the condenser of the R410A system may be operating above the refrigerant's critical point. Part 1 of this project consisted of conducting comprehensive measurements of thermophysical for refrigerant R125 and refrigerant blends R410A and R507A and developing new equation of state formulations and mixture models for predicting thermophysical properties of HFC refrigerant blends. Part 2 of this project conducted performance measurements of split-system, 3-ton R22 and R410A residential air conditioners in the 80 to 135 F (27.8 to 57.2 C) outdoor temperature range and development of a system performance model. The performance data was used in preparing a beta version of EVAP-COND, a windows-based simulation package for predicting performance of finned-tube evaporators and condensers. The modeling portion of this project also included the formulation of a model for an air-conditioner equipped with a thermal expansion valve (TXV). Capacity and energy efficiency ratio (EER) were measured and compared. The R22 system's performance was measured over the outdoor ambient temperature range of 80 to 135 F (27.8 to 57.2 C). The same test range was planned for the R410A system. However, the compressor's safety system cut off the compressor at the 135.0 F (57.2 C) test temperature. The highest measurement on this system was at 130.0 F (54.4 C). Subsequently, a custom-manufactured R410A compressor with a disabled safety system and a more powerful motor was installed and performance was measured at outdoor temperatures up to 155.0 F (68.3 C). Both systems had similar capacity and EER performance at 82.0 F (27.8 C). The capacity and EER degradation of both systems were nearly linearly dependent with rising ambient outdoor ambient test temperatures. The performance degradation of R410A at higher temperatures was greater than R22. However, the R22 and R410A systems both operated normally during all tests. Visual observations of the R410A system provided no indication of vibrations or TXV hunting at high ambient outdoor test conditions with the compressor operating in the transcritical regime.

Piotr A. Domanski; W. Vance Payne

2002-10-31

148

Supercooling Refrigerator  

NASA Technical Reports Server (NTRS)

A Goddard/Philips research project resulted in a refrigeration system which works without seals, lubricants or bearings. The system, originally developed to cool satellite-based scientific instruments, has an extensive range of potential spinoffs. It is called the Stirling Cycle Cryogenic Cooler and eliminates friction by using electronically controlled linear magnetic bearings. Mechanical failure, contamination are eliminated.

1986-01-01

149

Kylteknik ("KYL")Kylteknik ("KYL") RefrigerationRefrigerationRefrigerationRefrigeration  

E-print Network

, geothermal energy, solar energy, biogas fuel, etc. Absorption refrigeration involves absorption requires temperatures above 0 °C) Ammonia / water AR system /1Ammonia / water AR system /1 Hot Engineering Piispankatu 8, 20500 Turku 4/40 ...continues #12;Ammonia / water AR system /2Ammonia / water AR

Zevenhoven, Ron

150

HFC-6000 for Nuclear I and C Upgrade  

SciTech Connect

The scalability of the HFC-6000 product line makes it an effective solution for nuclear power plant I and C upgrade applications. Its 19-in. rack-mounted platform provides a modular structure whose components can be used for many different nuclear power plant safety applications. This single-platform solution reduces the overall complexity of I and C implementation by minimizing operational and maintenance requirements. The HFC-6000 product line is designed to operate with either single or multiple control remote units in each channel. The main controller module in a remote unit is the system controller (HFCSBC06), which executes control logic programs, I/O scan, and C-Link communication. All three functions are handled by dedicated 64/32-bit microprocessors. A redundant configuration of system controllers consists of two HFC-SBC06 modules and one HFC-DPM06 dual-ported memory module. The hardware interface with external peripheral equipment is provided by an HFC-PCC06 peripheral interface module in the same rack. This module communicates with dedicated Control Switch Modules (the operator interface for digital control) and M/A stations (the operator interface for analog control), which are mounted on the plant main control board. Individual input/output modules serve as the hardware interface with the field devices under control and are implemented by different types of I/O modules. Each I/O module has a redundant serial communication interface. This serial interface employs a proprietary poll-response intercommunication link (ICL) protocol for communication with the system controllers. When a remote is configured with redundant controllers, the two ICL interfaces on each I/O module are connected to separate system controllers to create a redundant link. The I/O modules can be installed locally or remotely. If the I/O modules are physically remote from the controller, the ICL can be implemented with fiber optics to provide physical and electrical isolation from non-safety components. An HFC-FPD06 Flat Panel Display Module can be used as a human-machine interface (HMI). This HMI is composed of a qualified flat panel display and an HFC-FPC06 FPD controller. The FPC06 module has hardware interfaces for both the ICL and the fast Ethernet C-Link. It is configured as a subordinate to the HFC-SBC06 system controller and controls graphic displays on the HMI; it can also perform data voting and validation functions for redundant or triple redundant safety channels. The HFC-FPC06 can be used in either single or redundant configurations. The Power Supply Module consists of a redundant, rack-mounted power supply set. The typical configuration provides 24-vdc for all logic functions and 48-vdc for excitation power. Individual power supplies are redundant and hot swappable. Currently, HFC-6000 system is being installed in Kori Units no.1 to no.4 for its AAC D/G control and monitoring system and several other NPP I and C upgrade projects. (authors)

Taylor, Jonathan; Hsu, Allen; Gerardis, Terry; Stevens, John; McCreary, Tim; Yang, Steve [HF Controls Corporation, 16650 Westgrove Dr., Suite 500s (United States)

2006-07-01

151

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

SciTech Connect

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 LCCP 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.

Beshr, Mohamed [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Radermacher, Reinhard [University of Maryland, College Park

2014-01-01

152

Boiling heat transfer of refrigerant R-600a\\/R-290-oil mixtures in the serpentine small-diameter U-tubes  

Microsoft Academic Search

Flow boiling experiments for refrigerant R-600a, and R-290 mixed with the lubricating oil (EMKARATE) in the serpentine small-diameter (2.46mm) U-tubes are reported. The tests were conducted at the nominal inlet pressure of 186.2kPa, vapor qualities (0–0.76), mass flux of 100–320 (kg\\/m2s) and inlet oil concentrations from 0 to 5mass% oil. It was noted that a significant degradation of heat transfer

Mao-Yu Wen; Ching-Yen Ho; Jang-Kuen Jang

2007-01-01

153

Condensation heat-transfer and pressure drop characteristics of refrigerant R-290\\/R-600a–oil mixtures in serpentine small-diameter U-tubes  

Microsoft Academic Search

Flow condensing experiments for refrigerant R-290, and R-600a mixed with the lubricating oil (EMKARATE RL 32H) in serpentine small-diameter (2.46mm) U-tubes are reported. The tests were run at the saturation temperature of 40°C, vapor qualities of 0.41–0.82, mass flux of 300–600 (kg\\/m2s) and inlet oil concentrations from 0 to 5mass% oil. It was found that the condensation heat-transfer coefficients increased

Mao-Yu Wen; Ching-Yen Ho

2009-01-01

154

Refrigerant pressurization system with a two-phase condensing ejector  

DOEpatents

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.

Bergander, Mark (Madison, CT)

2009-07-14

155

Global emissions of HFC-143a (CH3CF3) and HFC-32 (CH2F2) from in situ and air archive atmospheric observations  

NASA Astrophysics Data System (ADS)

High-frequency, in situ observations from the Advanced Global Atmospheric Gases Experiment (AGAGE), for the period 2003 to 2012, combined with archive flask measurements dating back to 1977, have been used to capture the rapid growth of HFC-143a (CH3CF3) and HFC-32 (CH2F2) mole fractions and emissions into the atmosphere. Here we report the first in situ global measurements of these two gases. HFC-143a and HFC-32 are the third and sixth most abundant hydrofluorocarbons (HFCs) respectively and they currently make an appreciable contribution to the HFCs in terms of atmospheric radiative forcing (1.7 ± 0.04 and 0.7 ± 0.02 mW m-2 in 2012 respectively). In 2012 the global average mole fraction of HFC-143a was 13.4 ± 0.3 ppt (1?) in the lower troposphere and its growth rate was 1.4 ± 0.04 ppt yr-1; HFC-32 had a global mean mole fraction of 6.2 ± 0.2 ppt and a growth rate of 1.1 ± 0.04 ppt yr-1 in 2012. The extensive observations presented in this work have been combined with an atmospheric transport model to simulate global atmospheric abundances and derive global emission estimates. It is estimated that 23 ± 3 Gg yr-1 of HFC-143a and 21 ± 11 Gg yr-1 of HFC-32 were emitted globally in 2012, and the emission rates are estimated to be increasing by 7 ± 5% yr-1 for HFC-143a and 14 ± 11% yr-1 for HFC-32.

O'Doherty, S.; Rigby, M.; Mühle, J.; Ivy, D. J.; Miller, B. R.; Young, D.; Simmonds, P. G.; Reimann, S.; Vollmer, M. K.; Krummel, P. B.; Fraser, P. J.; Steele, L. P.; Dunse, B.; Salameh, P. K.; Harth, C. M.; Arnold, T.; Weiss, R. F.; Kim, J.; Park, S.; Li, S.; Lunder, C.; Hermansen, O.; Schmidbauer, N.; Zhou, L. X.; Yao, B.; Wang, R. H. J.; Manning, A. J.; Prinn, R. G.

2014-09-01

156

Global emissions of HFC-143a (CH3CF3) and HFC-32 (CH2F2) from in situ and air archive atmospheric observations  

NASA Astrophysics Data System (ADS)

High frequency, in situ observations from the Advanced Global Atmospheric Gases Experiment (AGAGE), for the period 2003 to 2012, combined with archive flask measurements dating back to 1977, have been used to capture the rapid growth of HFC-143a (CH3CF3) and HFC-32 (CH2F2) mole fractions and emissions into the atmosphere. Here we report the first in situ global measurements of these two gases. HFC-143a and HFC-32 are the third and sixth most abundant HFCs respectively and they currently make an appreciable contribution to the HFCs in terms of atmospheric radiative forcing (1.7 and 0.7 mW m2 in 2012, respectively). In 2012 the global average mole fraction of HFC-143a was 13.4 ± 0.3 ppt (1-sigma) in the lower troposphere and its growth rate was 1.4 ± 0.04 ppt yr-1; HFC-32 had a global mean mole fraction of 6.2 ± 0.2 ppt and a growth rate of 1.1 ± 0.04 ppt yr-1 in 2012. The extensive observations presented in this work have been combined with an atmospheric transport model to simulate global atmospheric abundances and derive global emission estimates. It is estimated that 23 ± 3 Gg yr-1 of HFC-143a and 21 ± 11 Gg yr-1 of HFC-32 were emitted globally in 2012, and the emission rates are estimated to be increasing 7 ± 5% yr-1 for HFC-143a and 14 ± 11% yr-1 for HFC-32.

O'Doherty, S.; Rigby, M.; Mühle, J.; Ivy, D. J.; Miller, B. R.; Young, D.; Simmonds, P. G.; Reimann, S.; Vollmer, M. K.; Krummel, P. B.; Fraser, P. J.; Steele, L. P.; Dunse, B.; Salameh, P. K.; Harth, C. M.; Arnold, T.; Weiss, R. F.; Kim, J.; Park, S.; Li, S.; Lunder, C.; Hermansen, O.; Schmidbauer, N.; Zhou, L. X.; Yao, B.; Wang, R. H. J.; Manning, A.; Prinn, R. G.

2014-03-01

157

Choked flow mechanism of HFC-134a flowing through short-tube orifices  

SciTech Connect

This paper is a continuation of the author's previous work. New experimental data on the occurrence of choked flow phenomenon and mass flow rate of HFC-134a inside short-tube orifices under choked flow condition are presented. Short-tube orifices diameters ranging from 0.406 mm to 0.686 mm with lengths ranging from 1 mm to 3 mm which can be applied to a miniature vapour-compression refrigeration system are examined. The experimental results indicated that the occurrence of choked flow phenomena inside short-tube orifices is different from that obtained from short-tube orifice diameters of greater than 1 mm, which are typically used in air-conditioner. The beginning of choked flow is dependent on the downstream pressure, degree of subcooling, and length-to-diameter ratio. Under choked flow condition, the mass flow rate is greatly varied with the short-tube orifice dimension, but it is slightly affected by the operating conditions. A correlation of mass flow rate through short-tube orifices is proposed in terms of the dimensionless parameters. The predicted results show good agreement with experimental data with a mean deviation of 4.69%. (author) transfer coefficient was also proposed. (author)

Nilpueng, Kitti; Wongwises, Somchai [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok (Thailand)

2011-02-15

158

Oil separator for refrigeration systems  

SciTech Connect

This patent describes a method of separating oil from the mixture of compressed refrigerant gas, in which oil is entrained, which is discharged from a screw compressor to an oil separator in a refrigeration system. It comprises delivering the mixture at compressor pressure to the oil separator; splitting the flow of the mixture into relatively equal portions prior to separating the oil therefrom; delivering each of the split portions of the mixture to a different location internal of the oil separator; imparting a swirling motion to each of the portions of the mixture at each of the different locations internal of the separator so as to centrifugally disentrain oil from each of the portions of the mixture at each of the different locations; collecting the oil disentrained from each of the portions of the mixture at each of the different locations in a common sump; and driving the disentrained oil and the gas from which the oil has been disentrained out of the oil separator under the impetus of compressor discharge pressure.

Carey, M.D.

1991-07-09

159

Refrigerant directly cooled capacitors  

DOEpatents

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.

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

160

Fluorescent refrigeration  

DOEpatents

Fluorescent refrigeration is based on selective radiative pumping, using substantially monochromatic radiation, of quantum excitations which are then endothermically redistributed to higher energies. Ultimately, the populated energy levels radiatively deexcite emitting, on the average, more radiant energy than was initially absorbed. The material utilized to accomplish the cooling must have dimensions such that the exciting radiation is strongly absorbed, but the fluorescence may exit the material through a significantly smaller optical pathlength. Optical fibers and mirrored glasses and crystals provide this requirement. 6 figs.

Epstein, R.I.; Edwards, B.C.; Buchwald, M.I.; Gosnell, T.R.

1995-09-05

161

Research on HFC network broadband access using WLAN technology  

NASA Astrophysics Data System (ADS)

Current broadband access system such as ADSL can not satisfy the network applications as the development of network services. In this paper, we proposed to use WLAN technology on the HFC network as a terminal broadband access plan. First of all, theoretical analysis is given to support the feasibility of using WLAN technology on the HFC network. Then, transmission experiments and results of the proposed plan are described in this paper. The key point of the plan is to use a WLAN access point device as a modem to modulate the baseband Ethernet signal into 2.4GHz WLAN signal which then be transmitted via coaxial cable(COAX). The experimental results show that the average traffic throughput of the system could reach to approximate 20Mbps which is the theoretical throughput of 802.11g WLAN transmission. And the transmission throughput has no remarkable change no matter there is CATV signal in the system or not. Finally, conclusions are drawn out: The proposed system can work properly. WLAN signal is quite suitable to be transmitted in the coaxial cable. CATV signal and WLAN signal are not interfering with each other in the system. Using WLAN on the existing coaxial cable which has already accessed to thousands of people's home could be a cost-effective plan for broadband access on the HFC network.

Chang, Yuguang; Liu, Deming; Zhang, Shu; Wu, Guangsheng

2007-11-01

162

Reduced-temperature processing and consolidation of ultra-refractory Ta4HfC5  

SciTech Connect

TaC, HfC, and WC powders were subjected to high-energy milling and hot pressing to produce Ta4HfC5, a composite of Ta(4)HfC5 + 30 vol.% WC, and a composite of Ta4HfC5 + 50 vol.% WC. Sub-micron powders were examined after four different milling intervals prior to hot pressing. XRD was used to verify proper phase formation. SEM, relative density, and hardness measurements were used to examine the resulting phases. Hot pressed compacts of Ta4HfC5 showed densification as high as 98.6% along with Vickers hardness values of 21.4 GPa. Similarly, Ta4HfC5 + 30 vol.% WC exhibited 99% densification with a Vickers hardness of 22.5 GPa. These levels of densification were achieved at 1500 degrees C, which is lower than any previously reported sintering temperature for Ta4HfC5. Microhardness values measured in this study were higher than those previously reported for Ta4HfC5. The WC additions to Ta4HfC5 were found to improve densification and increase microhardness. (C) 2013 Elsevier Ltd. All rights reserved.

Gaballa, Osama [Ames Laboratory; Cook, B. A. [TRI International; Russell, A. M. [Ames Laboratory

2013-04-26

163

LABORATORY INVESTIGATIONS OF INTERACTIONS OF IRRADIATED O-XYLENE/NOX/SO2/AIR MIXTURES WITH AQUEOUS MEDIA CONTAINING SODIUM FLUORIDE, SODIUM TRIFLUOROACETATE, AMMONIUM NITRATE AND HYDROGEN PEROXIDE  

EPA Science Inventory

Laboratory experiments were conducted to investigate interactions between complex air mixtures and aqueous films containing hydrolysis products of hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) oxidation products. he experiments consisted of exposing aqueous films con...

164

Aging of Polyurethane Foam Insulation in Simulated Refrigerator Panels--Three-Year Results with Third-Generation Blowing Agents  

SciTech Connect

Laboratory data are presented on the effect of constant-temperature aging on the apparent thermal conductivity of polyurethane foam insulation for refrigerators and freezers. The foam specimens were blown with HCFC-141b and with three of its potential replacements--HFC-134a, HFC-245fa, and cyclopentane. Specimens were aged at constant temperatures of 90 F, 40 F, and -10 F. Thermal conductivity measurements were made on two types of specimens: full-thickness simulated refrigerator panels containing foam enclosed between solid plastic sheets, and thin slices of core foam cut from similar panels. Results are presented for the first three years of a multi-year aging study. Preliminary comparisons of measured data with predictions of a mathematical aging model are presented.

Wilkes, K.E.

2001-05-29

165

Aging of Polyurethane Foam Insulation in Simulated Refrigerator Panels--One-Year Results with Third-Generation Blowing Agents  

SciTech Connect

Laboratory data are presented on the effect of constant-temperature aging on the apparent thermal conductivity of polyurethane foam insulation for refrigerators and freezers. The foam specimens were blown with HCFC-141b and with three of its potential replacements--HFC-134a, HFC-245fa, and cyclopentane. Specimens were aged at constant temperatures of 90 F, 40 F, and {minus}10 F. Thermal conductivity measurements were made on two types of specimens: full-thickness simulated refrigerator panels containing foam enclosed between solid plastic sheets, and thin slices of core foam cut from similar panels. Results are presented for the first year of a multi-year study for the full-thickness panels and for about 1-1/2 years of aging for the core-foam specimens.

Gabbard, W.A.; Weaver, F.J.; Wilkes, K.E.

1999-09-27

166

REACH. Refrigeration Units.  

ERIC Educational Resources Information Center

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…

Snow, Rufus; And Others

167

The performance of a triple pressure level absorption cycle (TPLAC) with working fluids based on the absorbent DMEU and the refrigerants R22, R32, R124, R125, R134a and R152a  

Microsoft Academic Search

This paper compares the performance of a single-stage triple pressure level (TPL) absorption cycle with different refrigerant–absorbent pairs. Four HFC refrigerants namely: R32, R125, R134a and R152a which are alternative to HCFC, such as R22 and R124, in combination with the absorbent dimethylethylenurea (DMEU) were considered. The highest coefficient of performance (COP) and the lowest circulation ratio (f), were found

M. Jelinek; A. Levy; I. Borde

2008-01-01

168

Investigation of horizontal flow boiling of pure and mixed refrigerants  

SciTech Connect

The research involved determining experimental heat-transfer coefficients (HTC), examining the phenomena involved in the physical process, and analyzing the predictive ability of available models and correlations. This work was done for pure R152a and R13B1 and for mixtures of these refrigerants. The mixtures yielded sharply lower heat transfer coefficients than either pure refrigerant. With pure refrigerants, full suppression of nucleate boiling (FSNB) occurs only at rather low pressures. Correlative evidence suggests that suppression is easier to achieve with mixtures than pure fluids. In the evaporation-dominated heat-transfer regime, Chen's correlation was successfully applied to the refrigerants with and without the occurrence of FSNB conditions. In the nucleate-boiling-dominated regime, the Stephan and Abdelsalam method was validated for pure fluids, and used successfully with Thome's method for mixtures. Pressure-drop correlations for pure fluids were also extended to mixtures without modification.

Ross, H.D.

1986-11-01

169

ARTI refrigerant database  

SciTech Connect

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.

Calm, J.M.

1996-11-15

170

ARTI refrigerant database  

SciTech Connect

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilities 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.

Calm, J.M. [Calm (James M.), Great Falls, VA (United States)

1999-01-01

171

ARTI refrigerant database  

SciTech Connect

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.

Calm, J.M.

1996-07-01

172

EVALUATION OF HFC-245FA AS A POTENTIAL ALTERNATIVE FOR CFC-11 IN LOW PRESSURE CHILLERS  

EPA Science Inventory

The paper reports results of an evaluation of HFC-245fa as a potential alternative for CFC-11 in low pressure chillers. (NOTE: It was reported previously that HFC245ca (1,1,2,2,3-pentafluoro-propane) has many attributes that make it an attractive candidate alternative for CFC-11 ...

173

NEW CHEMICAL ALTERNATIVE FOR OZONE-DEPLETING SUBSTANCES: HFC-245CA  

EPA Science Inventory

The report gives results of a preliminary evaluation of a new hydrofluorocarbon (HFC) -- HFC-245ca or 1,1,2,2,3-pentafluoropropane -- as a possible alternative for chlorofluorocarbon (CFC)-11 (trichlorofluoromethane) and hydrochlorofluorocarbon (HCFC)-123 (1,1,1-trifluoro-2,2-dic...

174

Adsorption of hydrofluorocarbons HFC-134 and HFC-134A on X and Y zeolites: Effect of ion-exchange on selectivity and heat of adsorption  

SciTech Connect

Adsorption isotherms and heats of adsorption were measured for HFC-134 (1,1,2,2-tetrafluoroethane) and HFC-134a (1,1,1,2-tetrafluoroethane) on a series of ion-exchanged (H, Li, Na, Rb, Cs) faujasites using volumetric and calorimetric techniques. The species and number of ions present in the zeolite strongly influence the heats of adsorption and the preferential adsorption of HFC-134 compared to HFC-134a. The selectivity is considerably higher in X than in Y zeolites because of the larger number of nonframework ions in X zeolites. The saturation capacity is six molecules per supercavity for both HFCs. The differences in observed heats of adsorption (except for RbX) can be explained by reasonable and consistent values of dispersion and ion-dipole electrostatic energies. The high selectivities for NaX and RbX indicate that either zeolite would be highly effective for gas separation.

Savitz, S.; Siperstein, F.R.; Huber, R.; Tieri, S.M.; Gorte, R.J.; Myers, A.L.; Grey, C.P.; Corbin, D.R.

1999-09-30

175

Adsorption of Hydrofluorocarbons HFC-134 and HFC-134A on X and Y Zeolites: Effect of Ion-Exchange on Selectivity and Heat of Adsorption  

E-print Network

species generally. 2. Experimental Section Materials. Ion-exchanged X and Y zeolites were provided by DuPont.) The adsorbates, HFC-134 (1,1,2,2-tetrafluoroethane) and HFC-134a (1,1,1,2-tetrafluoroethane) were provided by DuPont. Dehydration factors, f, defined as were obtained by TGA (DuPont Instruments TGA model 951) up to 500 °C

Siperstein, Flor R.

176

46 CFR 154.1735 - Methyl acetylene-propadiene mixture.  

Code of Federal Regulations, 2012 CFR

...is: (i) Maximum methyl acetylene and propadiene molar ratio of 3 to 1; (ii) Maximum combined concentration of methyl...acetylene-propadiene mixture must have a refrigeration system without vapor compression or have a refrigeration system with the following...

2012-10-01

177

46 CFR 154.1735 - Methyl acetylene-propadiene mixture.  

Code of Federal Regulations, 2013 CFR

...is: (i) Maximum methyl acetylene and propadiene molar ratio of 3 to 1; (ii) Maximum combined concentration of methyl...acetylene-propadiene mixture must have a refrigeration system without vapor compression or have a refrigeration system with the following...

2013-10-01

178

46 CFR 154.1735 - Methyl acetylene-propadiene mixture.  

...is: (i) Maximum methyl acetylene and propadiene molar ratio of 3 to 1; (ii) Maximum combined concentration of methyl...acetylene-propadiene mixture must have a refrigeration system without vapor compression or have a refrigeration system with the following...

2014-10-01

179

46 CFR 154.1735 - Methyl acetylene-propadiene mixture.  

Code of Federal Regulations, 2011 CFR

...is: (i) Maximum methyl acetylene and propadiene molar ratio of 3 to 1; (ii) Maximum combined concentration of methyl...acetylene-propadiene mixture must have a refrigeration system without vapor compression or have a refrigeration system with the following...

2011-10-01

180

Performance of a residential heat pump operating with a non-azeotropic binary refrigerant mixture - an interim report. [R22 vs non-azeotropic binary mixture of R13B1 and R152a  

Microsoft Academic Search

This report presents results of laboratory measurement of the performance change of a substantially unmodified residential heat pump designed for R22 when charged with a non-azeotropic, binary mixture of R13B1 and R152a. Results are presented for various sizes of fixed expansion devices. The effect of gliding temperature in the saturation zone was found to be small. The effect of composition

D. Didion; W. Mulroy

1984-01-01

181

Microminiature Refrigeration  

NASA Astrophysics Data System (ADS)

The dramatic growth of industrial cryogenics in the past century has overshadowed the need for cryogenics on a smaller scale. Today, small scale, MEMS or microminiature refrigerators constitute a small part of the field, but one with a unique role to play, often in instrumentation. Key attributes of these coolers have proved to be their small size, low noise, fast response, and low cost. The small size has enabled the integration of the instrument and cooler. The fast response and low noise have made possible instruments of unique capabilities. Opportunities exist for the seamless integration of cryogenics in other products, but to succeed here, companies need strength in both cryogenics and a broad range of other disciplines, including materials science, electronics, and software. To offset economies of scale, new fabrication technologies have had to be created, and others are needed. Some key elements remain to be developed before more widespread use of this technology will be seen. Better miniature heat exchangers and regenerators are needed. Development of miniature compressors to power the coolers could herald a new world of cooled devices analogous to the revolution created by fractional horsepower electric motors in the past fifty years. Opportunities abound!

Little, W. A.

2008-03-01

182

Refrigerating machine oil  

SciTech Connect

Refrigerating machine oil to be filled in a sealed motorcompressor unit constituting a refrigerating cycle system including an electric refrigerator, an electric cold-storage box, a small-scaled electric refrigerating show-case, a small-scaled electric cold-storage show-case and the like, is arranged to have a specifically enhanced property, in which smaller initial driving power consumption of the sealed motor-compressor and easier supply of the predetermined amount of the refrigerating machine oil to the refrigerating system are both guaranteed even in a rather low environmental temperature condition.

Nozawa, K.

1981-03-17

183

Influence of Oil on Refrigerant Evaporator Performance  

NASA Astrophysics Data System (ADS)

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%.

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

184

Operational issues in a two-way HFC environment  

NASA Astrophysics Data System (ADS)

The push to reduce system operating cost and increase performance in a traditional cable television tree-and-branch architecture has led system designers to pursue the hybrid fiber- coaxial (HFC) architecture as a viable solution. This solution, which joins the photonic world with radio frequency (rf) transmission, yields favorable results with respect to transporting analog video services. As a result, system operating enhancements such as improved carrier- to-noise ratios, improved carrier-to-distortion measurements, and fewer active components in cascade are possible. In addition, an enabling platform for the deployment of other two-way interactive services, facilitating duplex transmission, is successfully accomplished. In order to realize this network, there are some acute operational issues that need to be addressed. The picture quality problems of the past have been minimized. However, the thought of transporting telephony and other digitally formatted signals gives rise to other technical operating concerns. The adverse effects of impulse noise and ingress in the down and upstream paths of the HFC plant on digital signals and ancillary data services are described in this paper. Experimental data shows how these impairments affect network reliability from a technical operational context.

Mends-Cole, Alex

1995-11-01

185

ARTI Refrigerant Database  

SciTech Connect

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.

Calm, J.M. [Calm (James M.), Great Falls, VA (United States)

1994-05-27

186

Plant Site Refrigeration Upgrade  

E-print Network

Bayer Corporation operates a multi-division manufacturing facility in Bushy Park, South Carolina. Low temperature refrigeration (-4°F) is required by many of the chemical manufacturing areas and is provided by a Plant Site Refrigeration System...

Zdrojewski, R.; Healy, M.; Ramsey, J.

187

Refrigeration for Cryogenic Sensors  

NASA Technical Reports Server (NTRS)

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.

Gasser, M. G. (editor)

1983-01-01

188

Save with Hybrid Refrigeration  

E-print Network

of refrigeration, consisting of an ammonia absorption refrigeration (AAR) unit and a mechanical compression refrigera tion (MCR) unit, is presented in this article. This paper will briefly describe process configur ation, advantages and utility consumption..., equip ment cost and direct field cost comparisons of such a hybri~ refrigeration unit over its coun terpart, a cascading MCR unit, in a Rectisol application. INTRODUCTION COMBINING REFRIGERATION SYSTEMS can save energy where two levels...

Chung, C. W.

189

Theoretical investigations on simultaneous operation of vapour compression refrigeration cycle and Stirling cycle in miniature Stirling cooler with two-component two-phase mixture  

NASA Astrophysics Data System (ADS)

The cyclic analysis of Stirling cycle working with a single gaseous fluid is modified to suit two-component two-phase mixtures. When the results were examined carefully, these showed that a substantial increase in cooling effect is obtained. In order to understand how the two-component two-phase working fluid functions in the Stirling cooler, some other processes, generally not coming into picture with a single gaseous fluid, are also considered to get good idea about the working of the cooler and then the estimates about the performance of the cooler are obtained. The processes include, simultaneous compression of gases with different ratios of Cp and Cv, the drop-wise condensation, isentropic expansion of liquid in presence of other gas, the entrainment process as observed in heat pipes, and saturation process as observed in air humidification process. The change in regenerator effectiveness due to condensation in the regenerator also has to be considered. How the above mentioned processes are affecting the system performance is discussed in detail. The analysis shows that the Stirling cycle and vapour compression cycle with isentropic expansion operate simultaneously. The criterion for selection of the gaseous carrier fluid and the condensable fluid, which undergoes phase change is established. For selection of carrier gas, helium and hydrogen are considered and for the condensable fluid, nitrogen, carbon mono-oxide, nitrogen-tri-fluoride and neon are compared. Using the above mentioned criterion, helium and nitrogen combination has been chosen for cold tip temperatures in liquid nitrogen temperature range. The paper discusses the analytical approach and the results indicate that the presence of vapour compression cycle with isentropic expansion, operating under a small difference between the condensation and evaporation temperatures, leads to high values of cooling effect and coefficient of performance (COP). It also shows that beyond a certain concentration, the cooling effect starts dropping and becomes zero at certain higher concentration. It can be mentioned that no changes in the hardware are necessary as the cooler can operate at pressures lower than normal working pressure and still provide large capacity with marginally higher power input.

Bapat, S. L.

2000-01-01

190

Energy-efficiency directory of refrigerators and refrigerator-freezers  

Microsoft Academic Search

Information is presented about the energy costs of operating refrigerators and refrigerator-freezers and includes the type of refrigerator or refrigerator-freezer, the fresh food volume, the freezer volume, the total volume, and the yearly energy cost. The directory lists all currently marketed electric refrigerators and refrigerator-freezers that have Energy Guide labels. The Federal Trade Commission requires manufacturers who distribute refrigerators and

T. G. Statt; J. L. Coggins

1981-01-01

191

The thermal conductivity of CFC alternatives HFC-125 and HCFC-141b in the liquid phase  

SciTech Connect

The liquid thermal conductivities of the CFC alternatives, HFC-125, and HCFC-141b measured by a transient hot-wire apparatus with one bare platinum wire are reported in the temperature ranges from 193 to 333 K (HFC- 125, CHF{sub 2}{center_dot}CF{sub 3}) and from 193 to 393 K (HCFC-141b, CCl{sub 2}F-CF{sub 3}), in the pressure ranges from 2 to 30 MPa (HFC-125) and from 0.1 to 30 MPa (HCFC- 141b), respectively. The results have been estimated to have an accurancy of {+-}0.5%. The liquid thermal conductives obtained have been correlated by a polynomial of temperature and pressure which can represent the experimental results within the standard deviations of 0.49% for HFC-125 and 0.46% for HCFC-141b, respectively.

Gao, X.; Yamada, T.; Nagasaka, Y. [Keio Univ., Yokohama (Japan)] [and others

1996-03-01

192

Performance and heat transfer characteristics of HFC134a and CFC12 in a water chiller  

Microsoft Academic Search

A water chiller with an open reciprocating compressor has been used to comparatively assess the performance of HFC-134a with reference to CFC-12 under as close to identical conditions as possible. Performance characteristics of the chiller under retrofit conditions show that HFC-134a offers better cooling load and coefficients of performance vis-a-vis CFC-12 for identical operating conditions. Further heat transfer analysis of

S. Devotta; M. G. Parande; V. R. Patwardhan

1998-01-01

193

HFC-134a emissions from mobile air conditioning in China from 1995 to 2030  

NASA Astrophysics Data System (ADS)

Since 1995, 1,1,1,2-tetrafluoroethane (CH2FCF3, HFC-134a) has become the most important substitute of CFC-12 in mobile air conditioning (MAC) in China and MAC sector has dominated all the emissions of HFC-134a. In this study, we developed an accurate, updated and county-level inventory of the HFC-134a emissions from MAC in China for the period of 1995-2030 with an improved bottom-up method. Our estimation indicated that the total HFC-134a emissions kept growing at increase rates of ?100% per year for 1995-2000 and ?34% per year for 2001-2010. In 2010, HFC-134a emissions from MAC in China reached 16.7 Gg (10.5-22.7 Gg at 95% confidential interval), equivalent to 21.7 Tg CO2 (CO2-eq). Furthermore, the emissions in China estimated in this study accounted for 9.8% of global HFC-134a emissions and 29.0% of total emissions from Non-Annex_I countries in 2010. Due to the more advanced social-economic conditions and more intensive ownership of automobiles, greater HFC-134a were observed to come from big cities in East China. Under a Business-as-usual (BAU) Scenario, projected emissions will grow to 89.4 (57.9-123.9) Gg (about 75.3-161.1 Tg CO2-eq) in 2030, but under an Alternative Scenario, 88.6% of the projected emissions under BAU scenario could be curbed. Our estimation demonstrates huge emission mitigation potential of HFC-134a in China's MAC sector.

Su, Shenshen; Fang, Xuekun; Li, Li; Wu, Jing; Zhang, Jianbo; Xu, Weiguang; Hu, Jianxin

2015-02-01

194

Historical emissions of HFC-23 (CHF3) in China and projections upon policy options by 2050.  

PubMed

Trifluoromethane (CHF3, HFC-23) is one of the hydrofluorocarbons (HFCs) regulated under the Kyoto Protocol with a global warming potential (GWP) of 14?800 (100-year). China's past, present, and future HFC-23 emissions are of considerable interest to researchers and policymakers involved in climate change. In this study, we compiled a comprehensive historical inventory (1980-2012) and a projection (2013-2050) of HFC-23 production, abatements, and emissions in China. Results show that HFC-23 production in China increased from 0.08 ± 0.05 Gg/yr in 1980 to 15.4 ± 2.1 Gg/yr (228 ± 31 Tg/yr CO2-eq) in 2012, while actual HFC-23 emissions reached a peak of 10.5 ± 1.8 Gg/yr (155 ± 27 Tg/y CO2-eq) in 2006, and decreased to a minimum of 7.3 ± 1.3 Gg/yr (108 ± 19 Tg/yr CO2-eq) in 2008 and 2009. Under the examined business-as-usual (BAU) scenario, the cumulative emissions of HFC-23 in China over the period 2013-2050 are projected to be 609 Gg (9015 Tg CO2-eq which approximates China's 2012 CO2 emissions). Currently, China's annual HFC-23 emissions are much higher than those from the developed countries, while it is estimated that by year 2027, China's historic contribution to the global atmospheric burden of HFC-23 will have surpassed that of the developed nations under the BAU scenario. PMID:24605818

Fang, Xuekun; Miller, Benjamin R; Su, Shenshen; Wu, Jing; Zhang, Jianbo; Hu, Jianxin

2014-04-01

195

Characteristics of a Mixed Refrigerant Vapor Compression Cycle  

NASA Astrophysics Data System (ADS)

In comparison with conventional refrigerants, the use of non-azeotropic binary mixtures of refrigerants in vapor compression refrigerating systems can result in extension of the application limits, higher reliability, and savings in power consumption. This paper discusses the high temperature heat pump system performance operating with mixed refrigerants. In order to survey the system performances with various mixtures, six kinds of mixtures are examined : R22-R1l4, R22-R11, R12-R114, R12-R11, R 12-R113, and R22-R12. Thermodynamic properties of the first five mixtures are calculated from the Peng-Robinson equation of state with the mixing rules proposed by Ototake, and R22-R12 mixtures by the BWR type equation of state proposed by Kagawa et al. When counter-flow heat exchangers with large surface areas are used for the evaporator and the condenser, the temperature differences between the refrigerant and the heat sink / source fluids can be reduced, and so the energy waste resulting from irreversible heat trasfer can be reduced. Comparing the mixed refrigerants with the pure ones by fixing the refrigerant temperature at the evaporator inlet and the dewpoint temperature at the condenser, higher coefficients of performance (COP), lower condensing pressures, and lower pressure ratios in the refrigerant compressor can be realized. But the performances of the mixtures with R114 as a less volatile component are not so good. When the heat transfer surface area is not large, the mean temperature difference becomes large. If the dewpoint temperatures at the evaporator and the condenser fixed, the range of composition for the improvement of the COP is restricted.

Hihara, Eiji; Muneta, Yoshihiro; Saito, Takamoto

196

ARTI refrigerant database  

SciTech Connect

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. 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 may be added at a later date. The database identifies sources of specific information on 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. Citations in this report are divided into the following topics: thermophysical properties; materials compatibility; lubricants and tribology; application data; safety; test and analysis methods; impacts; regulatory actions; substitute refrigerants; identification; absorption and adsorption; research programs; and miscellaneous documents. Information is also presented on ordering instructions for the computerized version.

Calm, J.M. [Calm (James M.), Great Falls, VA (United States)] [Calm (James M.), Great Falls, VA (United States)

1996-04-15

197

Refrigeration systems program summary  

NASA Astrophysics Data System (ADS)

In addition to saving energy, deploying advanced refrigeration technologies can substantially benefit the environment. Chlorofluorocarbons (CFCs) have been identified as a major cause of potential global climate change and about 20 pct. of the CFCs consumed by the U.S. are due to refrigeration systems. As the international Montreal Protocol will phase out CFC compounds no later than 2000, there is tremendous need to develop safe non-CFC refrigerants and working fluids, alternative refrigeration cycles, and non-CFC insulations for appliances. The U.S. Department of Energy (DOE) established the Refrigeration System Program in 1977 to lead a national effort to accelerate the deployment of cost effective and energy efficient air conditioning and refrigeration technologies. The program primarily conducts research and development on advanced refrigeration technologies. The program, managed by the Office of Building Technologies, which reports to DOE's Assistant Secretary for Conversation and Renewable Energy, encompasses several key activities such as investigating alternative refrigerants and refrigeration cycles, developing advanced technologies for future air conditioning and refrigeration equipment designs, and developing advanced appliance insulations.

1991-12-01

198

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

SciTech Connect

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; system 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.

Abdelaziz, Omar [ORNL] [ORNL; Fricke, Brian A [ORNL] [ORNL; Vineyard, Edward Allan [ORNL] [ORNL

2012-01-01

199

ARTI refrigerant database  

SciTech Connect

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 manufactures 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 may be added at a later date. The database identifies sources of specific information on many refrigerants including propane, ammonia, water, carbon dioxide, propylene, ethers, and others as well as azeotropic and zeotropic blends of these fluids. 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.

Calm, J.M. [Calm (James M.), Great Falls, VA (United States)

1998-08-01

200

ARTI refrigerant database  

SciTech Connect

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 may 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.

Calm, J.M.

1997-02-01

201

Energy-efficiency directory of refrigerators and refrigerator-freezers  

SciTech Connect

Information is presented about the energy costs of operating refrigerators and refrigerator-freezers and includes the type of refrigerator or refrigerator-freezer, the fresh food volume, the freezer volume, the total volume, and the yearly energy cost. The directory lists all currently marketed electric refrigerators and refrigerator-freezers that have Energy Guide labels. The Federal Trade Commission requires manufacturers who distribute refrigerators and refrigerator-freezers to attach Energy Guide labels to appliances manufactured on or after May 19, 1980. The data have been measured by manufacturers and/or their agents according to US Government standard test procedures.

Statt, T.G.; Coggins, J.L.

1981-06-01

202

Chemically assisted mechanical refrigeration process  

DOEpatents

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.

Vobach, A.R.

1987-11-24

203

Chemically assisted mechanical refrigeration process  

DOEpatents

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.

Vobach, Arnold R. (6006 Allentown Dr., Spring, TX 77389)

1987-01-01

204

Chemically assisted mechanical refrigeration process  

DOEpatents

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.

Vobach, A.R.

1987-06-23

205

Chemically assisted mechanical refrigeration process  

DOEpatents

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.

Vobach, Arnold R. (6006 Allentown Dr., Spring, TX 77379)

1987-01-01

206

Waste Heat Recovery from Refrigeration  

E-print Network

-product of the refrigeration cycle becomes economically justifiable. This paper treats the history of the refrigeration machine, and the modern developments which have made available the system concept of waste heat recovery from refrigeration. A typical application...

Jackson, H. Z.

1982-01-01

207

Miscibility of lubricants with refrigerants, Phase 1  

SciTech Connect

Miscibility data have been obtained for a variety of non-CFC refrigerants and their potential lubricants. Ten different refrigerants and seven different lubricants were investigated. Experiments are being performed in two phases: Phase I, reported herein, focuses on performing screening tests for miscibility and Phase II consists of developing miscibility plots. The miscibility tests are being performed in a test facility consisting of a series of miniature test cells submerged in a constant temperature bath. The bath temperature can be precisely controlled over a temperature range of -50 C to 90C(-58 F to 194 F). The test cells are constructed to allow for complete visibility of lubricant-refrigerant mixtures under all test conditions.

Pate, M.B.; Zoz, S.C.; Berkenbosch, L.J. (Iowa State Univ. of Science and Technology, Ames, IA (United States). Dept. of Agricultural Engineering)

1992-10-01

208

HFC-134a Emissions in China: An Inventory for 1995-2030  

NASA Astrophysics Data System (ADS)

HFC-134a is the most important substitute of CFC-12 used in the mobile air-conditioner in China since 1995. The bottom-up method was used to estimate HFC-134a emissions in China, from 1995 to 2030, basing on updated automobile industry data and latest emission characters. From 1995, total HFC-134a emission has kept a high growth rate of nearly 60% per year, and reached 16,414.3 Mg (11,959.4-20,834.5 Mg) in 2010, which was equivalent to 23.5 Mt CO2-eq emissions. Furthermore, the emissions in China accounted for nearly half of total emissions of Non-AnnexI countries in 2008. As for provincial emissions in 2010, provinces with emission greater than 1,000 Mg are Guangdong, Shandong, Jiangsu and Beijing. Quantitative relationship between provincial HFC-134a emissions and GRP of the Tertiary Industry was used to estimate HFC-134a emissions at county level, and Hangzhou municipal district held the maximum emission intensity (4,605 Mg/10,000 km2). For HFC-134a, emissions calculated from the observations within 46 cities through Euler box model are in good agreement with the corresponding emissions estimated from the bottom-up method, verifying that the emission inventory at county level adequately describes the emission spatial pattern. For the future emissions of HFC-134a, projected emissions will reach 89,370.4 Mg (65,959.7- 114,068.2 Mg) in 2030 under the Business-as-usual (BAU) Scenario, but under the Alternative Scenario, a emission reduction potential of 88.6% of the projected BAU emissions would be obtained.

Su, Shenshen; Fang, Xuekun; Wu, Jing; Li, Li; Hu, Jianxin; Han, Jiarui

2014-05-01

209

HFC-23 (CHF3) emission trend response to HCFC-22 (CHClF2) production and recent HFC-23 emission abatement measures  

E-print Network

HFC-23 (also known as CHF3 [CHF subscript 3], fluoroform or trifluoromethane) is a potent greenhouse gas (GHG), with a global warming potential (GWP) of 14 800 for a 100-year time horizon. It is an unavoidable by-product ...

Miller, B. R.

210

Selection of the most suitable refrigerant for a shell and tube condenser  

NASA Astrophysics Data System (ADS)

A theoretical performance study on a shell and tube condenser with various refrigerant blends was conducted for various ratios proposed by other researchers in the literature. The theoretical results showed that all of the alternative refrigerants investigated in the analysis have a slightly lower convective heat transfer coefficient than their base refrigerants. The refrigerant mixture of R290/R600, R152a/R125/R32 and R32/R134a were found to be the most proper replacement refrigerant among the alternatives.

Dalkilic, A. S.; Mahian, O.; Wongwises, S.

2014-02-01

211

ARTI Refrigerant Database  

SciTech Connect

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, though some may be added at a later date. The database identifies sources of specific information on R-32, R-123, R-124, R- 125, R-134a, R-141b, R142b, R-143a, R-152a, R-290 (propane), R-717 (ammonia), ethers, and others as well as azeotropic and zeotropic blends of these fluids. It addresses polyalkylene glycol (PAG), ester, and other lubricants. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits.

Calm, J.M.

1992-04-30

212

Rotary two-phase refrigeration apparatus and method  

SciTech Connect

Rotary vacuum evaporation of a primary refrigerant cools a secondary refrigerant mixed with it. The secondary refrigerant does not change state and meanders through a low pressure cooling circuit for refrigeration applications. The primary refrigerant changes state and remains in a short and secure circuit. Evaporation is produced at a surface around the axis of rotation and within the mixture by opposed centrifugal and centripetal forces acting through a narrow afferent mesial passage between rotating disks mounted on a hollow shaft. Vapor is stripped from the surface, scrubbed by cyclonic flow through the afferent mesial passage, and condensed by a centrifugal compressor, which is a centrifugal pump having its inlet communicating with the bore of the hollow shaft and the afferent mesial passage. Latent heat is drawn off by water, making this a water heater, and the water is produced by de-humidification. The primary refrigerant and the secondary refrigerant are cheap and environmentally harmless, e.g. propylene glycol and acetone. A method and apparatus for refrigeration using only water is disclosed. Energy efficiency is maximized by avoidance of positive displacement pumps and narrow conduits, and by operation during times when excess power is in the grid. 7 figs.

McCutchen, W.H.

1994-01-04

213

saturated liquid. The region above the vapor line is superheated vapor; that below the lower line is subcooled liquid. The region enclosed by the pair represents a mixture of liquid and  

E-print Network

for refrigeration at two different temperature levels--for the freezer compartment and for the refrigerator from the freezer compartment to the refrigerator compartment, and (2) p, the refrigerant will be a mixture of liquid and vapor, as usually occurs in a single-refrigerant system. One

Oak Ridge National Laboratory

214

Actinide extraction from simulated and irradiated spent nuclear fuel using TBP solutions in HFC-134a  

SciTech Connect

It was demonstrated that solutions of TBP-nitric acid adduct in liquid Freon HFC-134a (1.2 MPa, 25 deg. C) allowed for recovery of uranium with nearly the same effectiveness as supercritical CO{sub 2} at 30 MPa. At nearly quantitative recovery of U and Pu, a DF of ca. 10 can be attained on dissolution and extraction of simulated SNF samples. The possibility of recovery of actinides contained in cakes produced by oxide conversion of simulated and irradiated SNF with solutions of TBP and DBE in Freon HFC-134a was shown. (authors)

Shadrin, A.; Babain, V.; Kamachev, V.; Murzin, A.; Shafikov, D.; Dormidonova, A. [Khlopin Radium Institute, RPA, 28, 2-nd Murinskii ay., St-Petersburg (Russian Federation)

2008-07-01

215

Thermoacoustic engines and refrigerators  

SciTech Connect

This report is a transcript of a practice lecture given in preparation for a review lecture on the operation of thermoacoustic engines and refrigerators. The author begins by a brief review of the thermodynamic principles underlying the operation of thermoacoustic engines and refrigerators. Remember from thermodynamics class that there are two kinds of heat engines, the heat engine or the prime mover which produces work from heat, and the refrigerator or heat pump that uses work to pump heat. The device operates between two thermal reservoirs at temperatures T{sub hot} and T{sub cold}. In the heat engine, heat flows into the device from the reservoir at T{sub hot}, produces work, and delivers waste heat into the reservoir at T{sub cold}. In the refrigerator, work flows into the device, lifting heat Q{sub cold} from reservoir at T{sub cold} and rejecting waste heat into the reservoir at T{sub hot}.

Swift, G.

1996-12-31

216

Joule Thomson refrigerator  

NASA Astrophysics Data System (ADS)

A bi-directional Joule Thomson refrigerator is described, which is of simple construction at the cold end of the refrigerator. Compressed gas flowing in either direction through the Joule Thomson expander valve and becoming liquid, is captured in a container in direct continuous contact with the heat load. The Joule Thomson valve is responsive to the temperature of the working fluid near the valve, to vary the flow resistance through the valve so as to maintain a generally constant flow mass between the time that the refrigerator is first turned on and the fluid is warm, and the time when the refrigerator is near its coldest temperature and the fluid is cold. The valve is operated by differences in thermal coefficients of expansion of materials to squeeze and release a small tube which acts as the expander valve.

Chan, Chung K.; Gatewood, John R.

1988-10-01

217

Miniature thermoacoustic refrigerator  

NASA Astrophysics Data System (ADS)

A miniature thermoacoustic refrigerator was developed for cooling electronic components. The refrigerator is driven at 5,000 Hz by a piezoelectric driver and it consists of an acoustic resonator, a stack, and copper heat exchangers. The working fluid is pressurized helium gas between 10 to 20 atmospheres. Sound was produced with different piezoelectric drivers, a monomorph, a bimorph, and Tonpilz driver to achieve the highest intensity possible. Since the operating frequency is high, the refrigerator is compact, being about 10 cm long. Temperature differences of 12 C across the stack were achieved at sound levels of 160 dB. The performance of the refrigerator scaled with frequency according to existing models of thermoacoustic heat engines.

Symko, Orest G.

1994-04-01

218

Near azeotropic mixture substitute  

NASA Technical Reports Server (NTRS)

The present invention comprises a refrigerant mixture consisting of a first mole fraction of 1,1,1,2-tetrafluoroethane (R134a) and a second mole fraction of a component selected from the group consisting of a mixture of CHClFCF.sub.3 (R124) and CH.sub.3 CClF.sub.2 (R142b); a mixture of CHF.sub.2 CH.sub.3 (R152a) and CHClFCF.sub.3 (R124); a mixture of CHF.sub.2 CH.sub.3 (R152a) and CH.sub.3 CClF.sub.2 (R142b); and a mixture of CHClFCF.sub.3 (R124), CH.sub.3 CClF.sub.2 (R142b) and CHF.sub.2 CH.sub.3 (R152a).

Jones, Jack A. (Inventor)

1996-01-01

219

DOE/AHAM advanced refrigerator technology development project  

SciTech Connect

As part of the effort to improve residential energy efficiency and reduce greenhouse emissions from power plants, several design options were investigated for improving the energy efficiency of a conventionally designed domestic refrigerator-freezer. The program goal was to reduce the energy consumption of a 20-ft{sup 3} (570-L) top-mount refrigerator-freeze to 1.00 kWh/d, a 50% reduction from the 1993 National Appliance Energy Conservation Act (NAECA) standard. The options--such as improved cabinet and door insulation, a high-efficiency compressor, a low-wattage fan, a large counterflow evaporator, and adaptive defrost control--were incorporated into prototype refrigerator-freezer cabinets and refrigeration systems. The refrigerant HFC-134a was used as a replacement for CFC-12. The baseline energy performance of the production refrigerator-freezers, along with cabinet heat load and compressor calorimeter test results, were extensively documented to provide a firm basis for experimentally measured energy savings. The project consisted of three main phases: (1) an evaluation of energy-efficient design options using computer simulation models and experimental testing, (2) design and testing of an initial prototype unit, and (3) energy and economic analyses of a final prototype. The final prototype achieved an energy consumption level of 0.93 kWh/d--an improvement of 45% over the baseline unit and 54% over the 1993 NAECA standard for 20-fg{sup 3} (570-L) units. The manufacturer`s cost for those improvements was estimated at $134; assuming that cost is doubled for the consumer, it would take about 11.4 years to pay for the design changes. Since the payback period was thought to be unfeasible, a second, more cost-effective design was also tested. Its energy consumption level was 1.16 kWh/d, a 42% energy savings, at a manufacturer`s cost increase of $53. Again assuming a 100% markup, the payback for this unit would be 6.6 years.

Vineyard, E.A.; Sand, J.R.; Rice, C.K.; Linkous, R.L.; Hardin, C.V.; Bohman, R.H.

1997-03-01

220

THERMODYNAMIC PERFORMANCE LIMIT AND EVAPORATOR DESIGN CONSIDERATIONS FOR NARM-BASED DOMESTIC REFRIGERATOR-FREEZER SYSTEMS  

EPA Science Inventory

The paper gives results of an investigation of non-azeotrophic refrigerant mixtures (NARMs) for a two-temperature-level heat exchange process found in a domestic refrigerator-freezer. deal (constant air temperature) heat exhcange processes are assumed. he results allow the effect...

221

Elevated temperature ablation resistance of HfC particle-reinforced tungsten composites  

E-print Network

Elevated temperature ablation resistance of HfC particle-reinforced tungsten composites Dongju Lee ablation rates of the composites were much lower than those of monolithic tungsten. The improvementC reinforcement. © 2013 Elsevier Ltd. All rights reserved. 1. Introduction Tungsten and its alloys

Hong, Soon Hyung

222

HEAT TRANSFER EVALUATION OF HFC-236FA IN CONDENSATION AND EVAPORATION  

EPA Science Inventory

The report gives results of an evaluation of the shell-side heat transfer performance of hydrofluorocarbon (HFC)-236fa, which is considered to be a potential substitute for chlorofluorocarbon (CFC)-114 in Navy shipboard chillers, for both conventional finned [1024- and 1575-fpm (...

223

HEAT TRANSFER EVALUATION OF HFC-236FA IN CONDENSATION AND EVAPORATION  

EPA Science Inventory

The report gives results of an evaluation of the shell-side heat transfer performance of hydrofluorocarbon (HFC)-236fa, which is considered to be a potential substitute for chlorofluorocarbon (CFC)-114 in Navy shipboard chillers, for both conventional finned (1024- and 1575-fpm (...

224

HEAT TRANSFER EVALUATION OF HFC-236EA WITH HIGH PERFORMANCE ENHANCED TUBES IN CONDENSATION AND EVAPORATION  

EPA Science Inventory

The report gives results of an evaluation of the heat transfer performance of pure hydrofluorocarbon (HFC)-236ea for high performance enhanced tubes which had not been previously used in Navy shipboard chillers. Shell-side heat transfer coefficient data are presented for conde...

225

HEAT TRANSFER EVALUATION OF HFC-236EA WITH HIGH PERFORMANCE ENHANCED TUBES IN CONDENSATION AND EVAPORATION  

EPA Science Inventory

The report gives results of an evaluation of the heat transfer performance of pure hydrofluorocarbon (HFC)-236ea for high performance enhanced tubes which had not been previously used in Navy shipboard chillers. Shell-side heat transfer coefficient data are presented for condensa...

226

Evidence for under-reported western European emissions of the potent greenhouse gas HFC-23  

NASA Astrophysics Data System (ADS)

Western European emission inventories of the potent greenhouse gas trifluoromethane (HFC-23) are validated at a country level by combining 2-hourly atmospheric in-situ measurements at Jungfraujoch (Switzerland) and Mace Head (Ireland) with Lagrangian transport simulations. HFC-23 has an atmospheric lifetime of ˜270 yr and a 100-yr global warming potential (GWP) of 14,800 and is unintentionally produced during the manufacture of chlorodifluoromethane (HCFC-22). For the study region we derive emissions of 144-216 Mg/yr for July 2008-July 2010, which are 60-140% higher than the official emissions gathered from the national reports for the year 2009. The largest discrepancy is found for Italy, where our estimate of 26-56 Mg/yr exceeds the national inventory (2.6 Mg/yr) by more than an order of magnitude. These findings suggest that non-reported emissions from Annex 1 countries partly explain the recently derived gap between global bottom-up and top-down HFC-23 emission estimates. The results presented here provide independent information to relevant authorities on effective reporting of HFC-23 emissions, and demonstrate the potential of atmospheric measurements for real-world verification of greenhouse gas emissions.

Keller, Christoph A.; Brunner, Dominik; Henne, Stephan; Vollmer, Martin K.; O'Doherty, Simon; Reimann, Stefan

2011-08-01

227

Future emissions and atmospheric fate of HFC-1234yf from mobile air conditioners in Europe.  

PubMed

HFC-1234yf (2,3,3,3-tetrafluoropropene) is under discussion for replacing HFC-134a (1,1,1,2-tetrafluoroethane) as a cooling agent in mobile air conditioners (MACs) in the European vehicle fleet. Some HFC-1234yf will be released into the atmosphere, where it is almost completely transformed to the persistent trifluoroacetic acid (TFA). Future emissions of HFC-1234yf after a complete conversion of the European vehicle fleet were assessed. Taking current day leakage rates and predicted vehicle numbers for the year 2020 into account, European total HFC-1234yf emissions from MACs were predicted to range between 11.0 and 19.2 Gg yr(-1). Resulting TFA deposition rates and rainwater concentrations over Europe were assessed with two Lagrangian chemistry transport models. Mean European summer-time TFA mixing ratios of about 0.15 ppt (high emission scenario) will surpass previously measured levels in background air in Germany and Switzerland by more than a factor of 10. Mean deposition rates (wet + dry) of TFA were estimated to be 0.65-0.76 kg km(-2) yr(-1), with a maxium of ?2.0 kg km(-2) yr(-1) occurring in Northern Italy. About 30-40% of the European HFC-1234yf emissions were deposited as TFA within Europe, while the remaining fraction was exported toward the Atlantic Ocean, Central Asia, Northern, and Tropical Africa. Largest annual mean TFA concentrations in rainwater were simulated over the Mediterranean and Northern Africa, reaching up to 2500 ng L(-1), while maxima over the continent of about 2000 ng L(-1) occurred in the Czech Republic and Southern Germany. These highest annual mean concentrations are at least 60 times lower than previously determined to be a safe level for the most sensitive aquatic life-forms. Rainwater concentrations during individual rain events would still be 1 order of magnitude lower than the no effect level. To verify these results future occasional sampling of TFA in the atmospheric environment should be considered. If future HFC-1234yf emissions surpass amounts used here studies of TFA accumulation in endorheic basins and other sensitive areas should be aspired. PMID:22225403

Henne, Stephan; Shallcross, Dudley E; Reimann, Stefan; Xiao, Ping; Brunner, Dominik; O'Doherty, Simon; Buchmann, Brigitte

2012-02-01

228

One of the limitations of using refrigerant mixtures to achieve capacity modulation is that the range of capacity control and the temperature glide are both functions of the difference  

E-print Network

the mixture to exceed a temperature glide of 30 F (16.7°C). The mixture .R13Bl/R152a was selected for analysis problems. R13B1 has been mentioned as being potentially damaging to the ozone layer, while R152a could

Oak Ridge National Laboratory

229

Refrigeration and Air-Conditioning Technology Workshop  

NASA Astrophysics Data System (ADS)

The Alternative Fluorocarbon Environmental Acceptability Study (AFEAS), a consortium of fluorocarbon manufacturers, and the U.S. Department of Energy (DOE) are collaborating on a project to evaluate the energy use and global warming impacts of CFC alternatives. The goal of this project is to identify technologies that could replace the use of CFC's in refrigeration, heating, and air-conditioning equipment; to evaluate the direct impacts of chemical emissions on global warming; and to compile accurate estimates of energy use and indirect CO2 emissions of substitute technologies. The first phase of this work focused on alternatives that could be commercialized before the year 2000. The second phase of the project is examining not-in-kind and next-generation technologies that could be developed to replace CFC's, HCFC's, and HFC's over a longer period. As part of this effort, Oak Ridge National Laboratory held a workshop on June 23-25, 1993. The preliminary agenda covered a broad range of alternative technologies and at least one speaker was invited to make a brief presentation at the workshop on each technology. Some of the invited speakers were unable to participate, and in a few cases other experts could not be identified. As a result, those technologies were not represented at the workshop. Each speaker was asked to prepare a five to seven page paper addressing six key issues concerning the technology he/she is developing. These points are listed in the sidebar. Each expert also spoke for 20 to 25 minutes at the workshop and answered questions from the other participants concerning the presentation and area of expertise. The primary goal of the presentations and discussions was to identify the developmental state of the technology and to obtain comparable data on system efficiencies.

Lewis, P. J.; Counce, D. M.

1993-12-01

230

Determination of a vapor compression refrigeration system refrigerant charge  

NASA Astrophysics Data System (ADS)

A physical model is established in this paper to describe the heat transfer and two phase flow of a refrigerant in the evaporator and condenser of a vapor compression refrigeration system. The model is then used to determine the refrigerant charge in vapor compression units. The model is used for a sensitivity analysis to determine the effect that varing design parameters on the refrigerant charge. The model is also used to evaluate the effect of refrigerant charge and the thermal physical properties on the refrigeration cycle. The predicted value of the refrigerant charge and experimental data agree well. The model and the method presented in this paper could be used to design vapour compression units such as domestic refrigerators and air conditioners.

Yang, Chun-Xin; Dang, Chao-Bin

1995-09-01

231

ARTI Refrigerant Database  

SciTech Connect

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 including 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.

Cain, J.M. (Calm (James M.), Great Falls, VA (United States))

1993-04-30

232

Downhole pulse tube refrigerators  

SciTech Connect

This report summarizes a preliminary design study to explore the plausibility of using pulse tube refrigeration to cool instruments in a hot down-hole environment. The original motivation was to maintain Dave Reagor`s high-temperature superconducting electronics at 75 K, but the study has evolved to include three target design criteria: cooling at 30 C in a 300 C environment, cooling at 75 K in a 50 C environment, cooling at both 75 K and 30 C in a 250 C environment. These specific temperatures were chosen arbitrarily, as representative of what is possible. The primary goals are low cost, reliability, and small package diameter. Pulse-tube refrigeration is a rapidly growing sub-field of cryogenic refrigeration. The pulse tube refrigerator has recently become the simplest, cheapest, most rugged and reliable low-power cryocooler. The authors expect this technology will be applicable downhole because of the ratio of hot to cold temperatures (in absolute units, such as Kelvin) of interest in deep drilling is comparable to the ratios routinely achieved with cryogenic pulse-tube refrigerators.

Swift, G.; Gardner, D. [Los Alamos National Lab., NM (United States). Condensed Matter and Thermal Physics Group

1997-12-01

233

ARTI Refrigerant Database  

SciTech Connect

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 refrigerant circuits. A computerized version is available that includes retrieval software.

Calm, J.M.

1992-11-09

234

Adsorption Refrigeration System  

SciTech Connect

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 drawbacks 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.

Wang, Kai [ORNL; Vineyard, Edward Allan [ORNL

2011-01-01

235

Refrigerator recycling and CFCs  

SciTech Connect

Utility-sponsored refrigerator and freezer pick-up programs have removed almost 900,000 inefficient appliances from the North American electric grid to date. While the CFC-12 refrigerant from the discarded appliances is typically removed and recycled, in all but a few programs the CFC-11 in the foam insulation is not. About a quarter-billion pounds of CFC-11 are banked in refrigerator foam in the United States. Release of this ``bank`` of CFC, combined with that from foam insulation used in buildings, will be the largest source of future emissions if preventive measures are not taken. Methods exist to recover the CFC for reuse or to destroy it by incineration. The task of recycling or destroying the CFCs and other materials from millions of refrigerators is a daunting challenge, but one in which utilities can play a leadership role. E Source believes that utilities can profitably serve as the catalyst for public-private partnerships that deliver comprehensive refrigerator recycling. Rather than treating such efforts solely as a DSM resource acquisition, utilities could position these programs as a multifaceted service delivery that offers convenient appliance removal for homeowners, a solid waste minimization service for landfills, a source of recycled materials for industry, and a CFC recovery and/or disposal service in support of the HVAC industry and society`s atmospheric protection goals and laws. Financial mechanisms could be developed through these public-private enterprises to ensure that utilities are compensated for the extra cost of fully recycling refrigerators, including the foam CFC.

Shepard, M.; Hawthorne, W.; Wilson, A.

1994-12-31

236

Magnetic refrigeration for spacecraft systems  

SciTech Connect

Magnetic refrigerators, i.e., those that use the magnetocaloric effect of a magnetic working material in a thermodynamic cycle, offer potentially reliable, and efficient refrigeration over a variety of temperature ranges and cooling powers. A descriptive analysis of magnetic refrigeration systems is performed with particular emphasis on more efficient infrared detector cooling. Three types of magnetic refrigerator designs are introduced to illustrate some of the possibilities.

Barclay, J.A.

1981-01-01

237

MOBILE AIR CONDITIONER REFRIGERANT EVALUATION  

EPA Science Inventory

The paper discusses an evaluation of refrigerant from mobile air conditioners. The data gathered indicate that CFC-l2 refrigerant does not degrade significantly with use. Furthermore, while small amounts of contaminant are removed with the refrigerant during servicing, most of th...

238

COLD STORAGE DESIGN REFRIGERATION EQUIPMENT  

E-print Network

COLD STORAGE DESIGN AND REFRIGERATION EQUIPMENT REFRIGERATION OF FISH - PART 1 \\ "..\\- ,,, T I Fishery Leaflet 427 Washington 25, D. C. June 1956 REFRIGERATION OF FISH - PART em; COlD STORAGE DESIGN (Section 1), and F. Bruce Sanford (Section 1) Table of Contents Pages Section 1 - Cold Storage Design

239

Exergy analysis of magnetic refrigeration  

E-print Network

One of the main challenges of the industry today is to face its impact on global warming considering that the greenhouse effect problem is not be solved completely yet. Magnetic refrigeration represents an environment-safe refrigeration technology. The magnetic refrigeration is analysed using the second law analysis and introducing exergy in order to obtain a model for engineering application.

Lucia, Umberto

2010-01-01

240

Evaluation of design options for improving the energy efficiency of an environmentally safe domestic refrigerator-freezer  

SciTech Connect

In order to reduce greenhouse emissions from power plants and respond to regulatory actions arising from the National Appliance Energy Conservation Act (NAECA), several design options were investigated for improving the energy efficiency of a conventionally designed, domestic refrigerator-freezer. The options, such as improved cabinet insulation and high-efficiency compressor and fans, were incorporated into a prototype refrigerator-freezer cabinet and refrigeration system to produce a unit that is superior from an environmental viewpoint due to its lower energy consumption and the use of refrigerant HFC-134a as a replacement for CFC-12. Baseline energy performance of the original 1993 production refrigerator-freezer, along with cabinet heat load and compressor calorimeter test results, were extensively documented to provide a firm basis for experimentally measured energy savings. A detailed refrigerator system computer model was used to evaluate the energy savings for several design modifications that, collectively, could achieve a targeted energy consumption of 1.00 kWh/d for a 20 ft{sup 3} (570 l) top-mount, automatic-defrost, refrigerator-freezer. The energy consumption goal represents a 50% reduction in the 1993 NAECA standard for units of this size. Following the modeling simulation, laboratory prototypes were fabricated and tested to experimentally verify the analytical results and aid in improving the model in those areas where discrepancies occurred. While the 1.00 kWh/d goal was not achieved with the modifications, a substantial energy efficiency improvement of 22% (1.41 kWh/d) was demonstrated using near-term technologies. It is noted that each improvement exacts a penalty in terms of increased cost or system complexity/reliability. Further work on this project will analyze cost-effectiveness of the design changes and investigate alternative, more-elaborate, refrigeration system changes to further reduce energy consumption.

Vineyard, E.A.; Sand, J.R. [Oak Ridge National Lab., TN (United States); Bohman, R.H.

1995-03-01

241

The Effect of Modified Atmosphere Packaging and Addition of Rosemary Extract, Sodium Acetate and Calcium Lactate Mixture on the Quality of Pre-cooked Hamburger Patties during Refrigerated Storage  

PubMed Central

The effect of modified atmosphere packaging (MAP; 30% CO2+70% N2 or 100% N2) and an additive mixture (500 ppm rosemary extract, 3,000 ppm sodium acetate and 1,500 ppm calcium lactate) on the quality of pre-cooked hamburger patties during storage at 5°C for 14 d was evaluated. The addition of the additive mixture reduced aerobic and anaerobic bacteria counts in both 30% CO2-MAP (30% CO2+70% N2) and 100% N2-MAP (p<0.05). The 30% CO2-MAP was more effective to suppress the microbial growth than 100% N2-MAP, moreover the 30% CO2-MAP combined with additive mixture resulted in the lowest bacterial counts. The hamburger patties with additive mixture showed lower CIE L* and CIE a*, and higher CIE b* than those with no additive mixture. The 30% CO2-MAP tended to decrease the TBARS during storage regardless of the addition of additives. The use of 30% CO2-MAP in combination with additives mixture was effective for maintaining the quality and extending the shelf-life of pre-cooked hamburger patties. PMID:25049716

Muhlisin; Kang, Sun Moon; Choi, Won Hee; Lee, Keun Taik; Cheong, Sung Hee; Lee, Sung Ki

2013-01-01

242

PERFORMANCE EVALUATION OF A VARIABLE SPEED, MIXED REFRIGERANT HEAT PUMP  

EPA Science Inventory

The report gives results of an evaluation of the performance of an innovative heat pump, equipped with a distillation column to shift the composition of a zeotropic refrigerant mixture. t gives results of U.S. Department of Energy (DOE) rating tests and seasonal energy calculatio...

243

Compressor calorimeter performance of refrigerant blends: Comparative methods and results for a refrigerator/freezer application  

SciTech Connect

A protocol was developed to define calorimeter operating pressures for nonazeotropic refrigerant mixtures (NARMs) which corresponded with the saturated evaporator and condenser temperatures commonly used for pure refrigerants. Compressor calorimeter results were obtained using this equivalent-mean-temperature (EMT) approach and a generally applied Association of Home Appliance Manufacturers (AHAM) procedure at conditions characteristic of a domestic refrigerator-freezer application. Tests with R-12 and two NARMs indicate that compressor volumetric and isentropic efficiencies are nearly the same for refrigerants with similar capacities and pressure ratios. The liquid-line temperature conditions specified in the AHAM calorimeter rating procedure for refrigerator-freezer compressors were found to preferentially derate NARM performance relative to R-12. Conversion of calorimeter data taken with a fixed liquid-line temperature to a uniform minimal level of condenser subcooling is recommended as a fairer procedure when NARMs are involved. Compressor energy-efficiency-ratio (EER) and capacity data measured as a result of the EMT approach were compared to system performance calculated using an equivalent-heat-exchanger-loading (EHXL) protocol based on a Lorenz-Meutzner (L-M) refrigerator-freezer modeling program. The EHXL protocol was used to transform the calorimeter results into a more relevant representation of potential L-M cycle performance. The EMT method used to set up the calorimeter tests and the AHAM liquid-line conditions combined to significantly understate the cycle potential of NARMs relative to that predicted at the more appropriate EHXL conditions. Compressor conditions representative of larger heat exchanger sizes were also found to give a smaller L-M cycle advantage relative to R-12.

Rice, C K; Sand, J R

1993-01-01

244

Investigation of pressure drop in capillary tube for mixed refrigerant Joule-Thomson cryocooler  

SciTech Connect

A capillary tube is commonly used in small capacity refrigeration and air-conditioning systems. It is also a preferred expansion device in mixed refrigerant Joule-Thomson (MR J-T) cryocoolers, since it is inexpensive and simple in configuration. However, the flow inside a capillary tube is complex, since flashing process that occurs in case of refrigeration and air-conditioning systems is metastable. A mixture of refrigerants such as nitrogen, methane, ethane, propane and iso-butane expands below its inversion temperature in the capillary tube of MR J-T cryocooler and reaches cryogenic temperature. The mass flow rate of refrigerant mixture circulating through capillary tube depends on the pressure difference across it. There are many empirical correlations which predict pressure drop across the capillary tube. However, they have not been tested for refrigerant mixtures and for operating conditions of the cryocooler. The present paper assesses the existing empirical correlations for predicting overall pressure drop across the capillary tube for the MR J-T cryocooler. The empirical correlations refer to homogeneous as well as separated flow models. Experiments are carried out to measure the overall pressure drop across the capillary tube for the cooler. Three different compositions of refrigerant mixture are used to study the pressure drop variations. The predicted overall pressure drop across the capillary tube is compared with the experimentally obtained value. The predictions obtained using homogeneous model show better match with the experimental results compared to separated flow models.

Ardhapurkar, P. M. [Mechanical Engineering Department, Indian Institute of Technology Bombay, Mumbai, MS 400 076 India and S. S. G. M. College of Engineering Shegaon, MS 444 203 (India); Sridharan, Arunkumar; Atrey, M. D. [Mechanical Engineering Department, Indian Institute of Technology Bombay, Mumbai, MS 400 076 (India)

2014-01-29

245

Education in Helium Refrigeration  

SciTech Connect

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.

Gistau Baguer, G. M. [38330, Biviers (France)

2004-06-23

246

Solar Powered Refrigeration System  

NASA Astrophysics Data System (ADS)

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.

Ewert, Michael K.; Bergeron, David J., III

2002-09-01

247

Solar Powered Refrigeration System  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

248

On refrigerant compressors  

Microsoft Academic Search

The purpose of the work was to critically re-examine and investigate the evaluation of refrigerant compressors and to determine and discriminate between the factors which influence their characteristics. The objectives also included the investigation of techniques by which the characteristics can be established and the suggestion of ways in which compressor performance can be described and quantified. The particular compressor

Jim McGovern

1988-01-01

249

Heat powered refrigeration compressor  

NASA Astrophysics Data System (ADS)

This prototype will be of similar capacity as the compressor that will eventually be commercially produced. This unit can operate on almost any moderate temperature water heat source. This heat source could include such applications as industrial waste heat, solar, wood burning stove, resistance electrical heat produced by a windmill, or even perhaps heat put out by the condenser of another refrigeration system.

Goad, R. R.

250

76 FR 57612 - Energy Efficiency Program for Consumer Products: Test Procedures for Residential Refrigerators...  

Federal Register 2010, 2011, 2012, 2013

...Residential Refrigerators, Refrigerator-Freezers, and Freezers AGENCY...residential refrigerators, refrigerator-freezers, and freezers that will...Residential Refrigerators, Refrigerator- Freezers, and Freezers'' and...

2011-09-15

251

Global and regional emissions of HFC125 (CHF2CF3) from in situ and air archive atmospheric observations at AGAGE and SOGE observatories  

Microsoft Academic Search

High-frequency, in situ observations from the Advanced Global Atmospheric Gases Experiment (AGAGE) and System for Observation of halogenated Greenhouse gases in Europe (SOGE) networks for the period 1998 to 2008, combined with archive flask measurements dating back to 1978, have been used to capture the rapid growth of HFC-125 (CHF2CF3) in the atmosphere. HFC-125 is the fifth most abundant HFC,

S. O'Doherty; D. M. Cunnold; B. R. Miller; J. Mühle; A. McCulloch; P. G. Simmonds; A. J. Manning; S. Reimann; M. K. Vollmer; B. R. Greally; R. G. Prinn; P. J. Fraser; L. P. Steele; P. B. Krummel; B. L. Dunse; L. W. Porter; C. R. Lunder; N. Schmidbauer; O. Hermansen; P. K. Salameh; C. M. Harth; R. H. J. Wang; R. F. Weiss

2009-01-01

252

The thermal conductivity of liquid 1,1,1,2-tetrafluoroethane (HFC 134a)  

Microsoft Academic Search

The thermal conductivity of HFC 134a was measured in the liquid phase with the polarized transient hot-wire technique. The\\u000a experiments were performed at temperatures from 213 to 293 K at pressures up to 20 MPa. The data were analyzed to obtain correlations\\u000a in terms of density and pressure. This study is part of an international project coordinated by the Subcommittee

A. N. Gurova; U. V. Mardolcar; C. A. Nieto de Castro

1997-01-01

253

EFFECT OF RE-HEATING ON VIABILITY OF A 5-STRAIN MIXTURE OF L. MONOCYTOGENES IN VACUUM-SEALED PKGS OF FRANKFURTERS,COMMERCIALLY PREPARED WITH AND WITHOUT 2.0% POTASSIUM LACTATE, FOLLOWING REFRIGERATED OR FROZEN STORAGE  

Technology Transfer Automated Retrieval System (TEKTRAN)

The purpose of this study was to assess the effect of product formulation and storage times and temperatures on the viability of Listeria monocytogenes after re-heating of frankfurters. Individual links were inoculated with about 8.0 log10 CFU/package of a five-strain mixture of the pathogen, vacuu...

254

Quantitative comparisons of absorption cross-section spectra and integrated intensities of HFC-143a  

NASA Astrophysics Data System (ADS)

The integrated absorption cross-sections of HFC-143a (CH3CF3) differ substantially in the literature. This leads to an important uncertainty on the value of the radiative efficiency of this molecule. The ambiguity on the absorption cross-sections of HFC-143a is highlighted by the existence of two significantly different datasets in the HITRAN database. To solve the issue, we performed high-resolution Fourier transform infrared laboratory measurements of HFC-13a and compared the spectra with the two HITRAN datasets and with the data from the Pacific Northwest National Laboratory (PNNL). The experimental methods and data analysis techniques are examined and typical sources of errors are discussed. The integrated intensities of the main bands are compared to other literature values. It was found that the integrated absorption cross-section values in the highest range - around 13.8 ×10-17 cm .molecule-1 in the 570-1500 cm-1 spectral band - show the most consistency between authors.

Le Bris, Karine; Graham, Laura

2015-01-01

255

Thermal conductivity of halogenated ethanes, HFC-134a, HCFC-123, and HCFC-141b  

SciTech Connect

The gaseous thermal conductivity of three CFC alternatives, HFC-134a (1,1,1,2-tetrafluoroethane), HCFC-123 (1,1-dichloro-2,2,2-trifluoroethane), and HCFC-141b (1,1-dichloro-1-fluoroethane), has been measured in the temperature ranges 273-363 K (HFC-134a) and 313-373K (HCFC-123, JCFC-141b) at pressures up to saturation. The measurements were performed with a new improved transient hot-wire apparatus. The uncertainty of the experimental data is estimated to be within 1%. The gaseous thermal conductivity obtained in this work together with the liquid thermal-conductivity data from the literature were correlated with temperature and density by an empirical equation based on the excess thermal-conductivity concept. The equation is found to represent the experimental results with average deviations of 2.5% for HFC-134a, 0.75% for HCFC-123, and 0.55% for HCFC-141B, respectively.

Yamamoto, R. (Kyoto Univ. (Japan)); Matsuo, S.; Tanaka, Y. (Kobe Univ. (Japan))

1993-01-01

256

The thermal conductivity of liquid 1,1,1,2-tetrafluoroethane (HFC-134a)  

SciTech Connect

The thermal conductivity of HFC 134a was measured in the liquid phase with the polarized transient hot-wire technique. The experiments were performed at temperatures from 213 to 293 K at pressures up to 20 MPa. The data were analyzed to obtain correlations in terms of density and pressure. This study is part of an international project coordinated by the Subcommittee on Transport Properties of Commission I.2 of IUPAC, conducted to investigate the large discrepancies between the results reported by various authors for the transport properties of HFC 134a, using samples of different origin. Two samples of HFC 134a from different sources have been used. The thermal conductivity of the first sample was measured along the saturation line as a function of temperature and the data were presented earlier. The thermal conductivity of the second one, the round-robin sample, was measured as a function of pressure and temperature. These data were extrapolated to the saturation line and compared with the data obtained, previously in order to demonstrate the importance of the sample origin and their real purity. The accuracy of the measurements is estimated to be 0.5%. Finally, the results are compared with the existing literature data.

Gurova, A.N.; Mardolcar, U.V. [Inst. Superior Tecnico, Lisboa (Portugal). Dept. de Fisica; Nieto de Castro, C.A. [Univ. de Lisboa (Portugal)

1997-09-01

257

Design analysis of the Einstein refrigeration cycle  

SciTech Connect

After developing the theory of relativity, Albert Einstein spent several years working with Leo Szilard on absorption refrigeration cycles. In 1930, they obtained a US patent for a unique single pressure absorption cycle. The single pressure eliminates the need for a solution pump. Their cycle has only recently been rediscovered. The cycle utilizes butane as its refrigerant, ammonia as a pressure equalizing fluid, and water as an absorbing fluid. This cycle is dramatically different in both concept and detail than the better-known ammonia-water-hydrogen cycle. In this study, thermodynamic and mixture property models of the Einstein cycle were created to gain insight into the cycle's operating characteristics and to calculate its performance. A conceptual demonstration model was built and successfully operated, showing for the first time the viability of the cycle. The model results found that the system pressure is an important design parameter, with the COP having an optimum when the system pressure is equal to the saturation pressure of the butane refrigerant. It was also found that for a given system pressure, there is a maximum condenser-absorber temperature and a minimum evaporator temperature.

Shelton, S.V.; Delano, A.; Schaefer, L.A.

1999-07-01

258

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

Code of Federal Regulations, 2010 CFR

...false Definitions concerning commercial refrigerators, freezers and refrigerator-freezers. 431.62 Section 431.62 Energy...COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Refrigerators, Freezers and Refrigerator-Freezers §...

2010-01-01

259

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

Code of Federal Regulations, 2012 CFR

...false Definitions concerning commercial refrigerators, freezers and refrigerator-freezers. 431.62 Section 431.62 Energy...COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Refrigerators, Freezers and Refrigerator-Freezers §...

2012-01-01

260

16 CFR Appendix A2 to Part 305 - Refrigerators and Refrigerators-Freezers With Manual Defrost  

...2014-01-01 2014-01-01 false Refrigerators and Refrigerators-Freezers With Manual Defrost A2 Appendix A2...Appendix A2 to Part 305—Refrigerators and Refrigerators-Freezers With Manual Defrost Range...

2014-01-01

261

16 CFR Appendix A2 to Part 305 - Refrigerators and Refrigerators-Freezers With Manual Defrost  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Refrigerators and Refrigerators-Freezers With Manual Defrost A2 Appendix A2...Appendix A2 to Part 305—Refrigerators and Refrigerators-Freezers With Manual Defrost Range...

2011-01-01

262

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

Code of Federal Regulations, 2011 CFR

...false Definitions concerning commercial refrigerators, freezers and refrigerator-freezers. 431.62 Section 431.62 Energy...COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Refrigerators, Freezers and Refrigerator-Freezers §...

2011-01-01

263

16 CFR Appendix A2 to Part 305 - Refrigerators and Refrigerators-Freezers With Manual Defrost  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Refrigerators and Refrigerators-Freezers With Manual Defrost A2 Appendix A2...Appendix A2 to Part 305—Refrigerators and Refrigerators-Freezers With Manual Defrost Range...

2012-01-01

264

16 CFR Appendix A2 to Part 305 - Refrigerators and Refrigerators-Freezers With Manual Defrost  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Refrigerators and Refrigerators-Freezers With Manual Defrost A2 Appendix A2...Appendix A2 to Part 305—Refrigerators and Refrigerators-Freezers With Manual Defrost Range...

2013-01-01

265

16 CFR Appendix A2 to Part 305 - Refrigerators and Refrigerators-Freezers With Manual Defrost  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Refrigerators and Refrigerators-Freezers With Manual Defrost A2 Appendix A2...Appendix A2 to Part 305—Refrigerators and Refrigerators-Freezers With Manual Defrost Range...

2010-01-01

266

Discussion of Refrigeration Cycle Using Carbon Dioxide as Refrigerant  

NASA Astrophysics Data System (ADS)

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.

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

267

Compact acoustic refrigerator  

SciTech Connect

This invention is comprised of a compact acoustic refrigeration system that 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.

Bennett, G.A.

1991-12-31

268

Flammability Indices for Refrigerants  

NASA Astrophysics Data System (ADS)

This paper introduces a new index to classify flammable refrigerants. A question on flammability indices that ASHRAE employs arose from combustion test results of R152a and ammonia. Conventional methods of not only ASHRAE but also ISO and Japanese High-pressure gas safety law to classify the flammability of refrigerants are evaluated to show why these methods conflict with the test results. The key finding of this paper is that the ratio of stoichiometric concentration to LFL concentration (R factor) represents the test results most precisely. In addition, it has excellent correlation with other flammability parameters such as flame speed and pressure rise coefficient. Classification according to this index gives reasonable flammability order of substances including ammonia, R152a and carbon monoxide. Theoretical background why this index gives good correlation is also discussed as well as the insufficient part of this method.

Kataoka, Osami

269

Refrigerants in Transition  

E-print Network

ozone layer, resulting in harm to human health and the environment. LEGISLATIVE ACTION As a result of recogn~z~ng that these con cerns were of a global nature, an international meeting was held in Montreal, Canada. A document, called the Montreal.... Table I. Comparison of Selected Refrigerants Refrigerant Ozone Depletion Global Warming Potential Potential CFC-l1 1.0 1.0 CFC-12 1.0 3.1 CFC-113 0.8 1.4 * CFC-114 1.0 3.9 * CFC-115 0.6 7.6 * HCFC-22 0.05 0.35 HCFC-123 0.02 0.02 HCFC-124 0.02 0...

Stouppe, D. E.

270

Compact acoustic refrigerator  

DOEpatents

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.

Bennett, G.A.

1992-11-24

271

Superfluid thermodynamic cycle refrigerator  

DOEpatents

A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of .sup.3 He in a single phase .sup.3 He-.sup.4 He solution. The .sup.3 He in superfluid .sup.4 He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid .sup.3 He at an initial concentration in superfluid .sup.4 He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of .sup.4 He while restricting passage of .sup.3 He. The .sup.3 He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

Swift, Gregory W. (Santa Fe, NM); Kotsubo, Vincent Y. (La Canada, CA)

1992-01-01

272

Dual mixed refrigerant natural gas liquefaction  

Microsoft Academic Search

A process and apparatus is described for liquefying natural gas using two closed cycle, multicomponent refrigerants wherein a low level refrigerant cools and liquefies the gas by indirect heat exchange and a high level refrigerant cools and partially liquefies the low level refrigerant by indirect multistage heat exchange. The high level refrigerant is phase separated in order to use lighter

Y.-N. Liu; J. W. Pervier

1985-01-01

273

APPLIANCE EFFICIENCY REGULATIONS FOR REFRIGERATORS AND FREEZERS  

E-print Network

#12;#12;APPLIANCE EFFICIENCY REGULATIONS FOR REFRIGERATORS AND FREEZERS ROOM AIR CONDITIONERS sold in California: (a) Refrigerators, refrigerator-freezers, and freezers which can be operated in recreational vehicles and other mobile equipment; (2) those refrigerators and refrigerator-freezers with total

274

Instability of refrigeration system – A review  

Microsoft Academic Search

It is essential to ensure the stability for the normal operation of refrigeration systems. This paper reviews the researches on the theory and solutions of the instability of refrigeration systems. The instability of refrigeration systems includes two aspects: the two-phase flow instability in refrigeration system, the instability on refrigeration system control characteristics. As an inherent characteristic of two-phase evaporating flow,

Nan Liang; Shuangquan Shao; Hongbo Xu; Changqing Tian

2010-01-01

275

Refrigeration and Food Safety  

MedlinePLUS

... Administrative Forms Standard Forms Skip Navigation Z7_0Q0619C0JGR010IFST1G5B10H1 Web Content Viewer (JSR 286) Actions ${title} Loading... / Topics / ... Food Safety / Refrigeration and Food Safety Z7_0Q0619C0JGR010IFST1G5B10H3 Web Content Viewer (JSR 286) Actions ${title} Loading... Z7_ ...

276

Australian HFC, PFC and SF6 emissions: atmospheric verification  

NASA Astrophysics Data System (ADS)

The synthetic greenhouse gases (GHGs: hydrofluorocarbons - HFCs, perfluorocarbons - PFCs, and sulfur hexafluoride - SF6), emitted largely by the refrigeration, aluminium and electricity distribution industries respectively, are currently responsible for less than 2% of Australia's net long-lived GHG emissions (DCCEE, 2011). Nevertheless, they have attracted the attention of policymakers because (1) if their growth in concentrations and emissions continues unabated, particularly HFCs - currently growing at 10% per year - then they could be responsible globally (and in Australia) for more than 10% of the radiative forcing due to long-lived GHGs by 2050 (Velders et al., 2009); and (2) they provide the opportunity for a very cost-effective GHG mitigation strategy, because emissions can be reduced significantly through better engineering to minimize emissions, through a ban on dispersive uses (as solvents for example) and through the use of low GWP (Global Warming Potential) alternatives (for example hydrofluoroethers - HFEs). CSIRO, through its involvement in the AGAGE global program of monitoring non-carbon dioxide GHGs (Prinn et al., 2000), has been making high precision in situ measurements (12 per day) of HFCs, PFCs and SF6 at Cape Grim, Tasmania, since 2004, using a gas chromatograph-mass spectrometer detector (GC-MSD) fitted with a custom-built cryo-focussing unit (Medusa: Miller et al., 2008). The resultant data have been used to derive Australian emissions by inverse modelling (NAME, TAPM) and interspecies correlation (ISC). The overall agreement between so-called bottom-up estimates of Australian emissions, as reported to the UNFCCC (United Nations Framework Convention on Climate Change), and top-down estimates from atmospheric observations, using NAME, TAPM and ISC, is encouraging. Australian UNFCCC reported emissions (DCCEE, 2011) generally agree to within of 10% of emissions calculated from Cape Grim data, scaled on a population basis, with some notable exceptions. References DCCEE (2011), Australian National Greenhouse Accounts, National Inventory Report 2009, Volume 1, Australian Government Department of Climate Change and Energy Efficiency, 284 pp, April 2011. Miller, B., R. Weiss, P. Salameh, T. Tanhua, B. Greally, J. Muhle & P. Simmonds, Medusa: a sample pre-concentration and GC-MS detector system for in situ measurements of atmospheric trace halocarbons, hydrocarbons and sulphur compounds, Anal. Chem., 80 (5), 1536-1545, 2008. Prinn, R., R. Weiss, P. Fraser, P. Simmonds, D. Cunnold, F. Alyea, S. O'Doherty, P. Salameh, B. Miller, J. Huang, R. Wang, D. Hartley, C. Harth, P. Steele, G. Sturrock, P. Midgley & A. McCulloch, A history of chemically and radiatively important gases in air deduced from ALE/GAGE/AGAGE, Journal of Geophysical Research - Atmospheres, 105 (D14): 17751-17792, 2000.

Fraser, P.; Dunse, B.; Krummel, P. B.; Steele, P.; Manning, A. J.

2011-12-01

277

Thermoacoustic Refrigerator's Stack Optimization  

NASA Astrophysics Data System (ADS)

The standing wave thermoacoustic refrigerator, which uses sound generation to transfer heat, was developed rapidly during the past four decades. It was regarded as a new, promising and environmentally benign alternative to conventional compression vapor refrigerators, although it was not competitive regarding the coefficient of performance (COP) yet. Thus the aim of this paper is to enhance thermoacoustic refrigerator's stack performance through optimization. A computational optimization procedure of thermoacoustic stack design was fully developed. The procedure was designed to achieve optimal coefficient of performance based on most of the design and operating parameters. Cooling load and acoustic power governing equations were set assuming the linear thermoacoustic theory. Lagrange multipliers method was used as an optimization technique tool to solve the governing equations. Numerical analyses results of the developed design procedure are presented. The results showed that the stack design parameters are the most significant parameters for the optimal overall performance. The coefficient of performance obtained increases by about 48.8% from the published experimental optimization methods. The results are in good agreement with past established studies.

El-Fawal, Mawahib Hassan; Mohd-Ghazali, Normah; Yaacob, Mohd. Shafik; Darus, Amer Nordin

2010-06-01

278

Vaccine refrigerator testing. Final report  

SciTech Connect

For the Central American Health Clinic Project initiated in 1986, Sandia National Laboratories and the Florida Solar Energy Center recognized the need for a test and evaluation program for vaccine refrigeration systems. At the Florida Solar Energy Center, side-by-side testing of three photovoltaic powered vaccine refrigerators began in 1987. The testing was expanded in 1988 to include a kerosene absorption refrigerator. This report presents observations, conclusions, and recommendations derived from testing the four vaccine refrigeration systems. Information is presented pertaining to the refrigerators, photovoltaic arrays, battery subsystems, charge controllers, and user requirements. This report should be of interest to designers, manufacturers, installers, and users of photovoltaic-powered vaccine refrigeration systems and components.

Ventre, G.G. [Univ. of Central Florida, Orlando, FL (United States); Kilfoyle, D.; Marion, B. [Florida Solar Energy Center, Cape Canaveral, FL (United States)

1990-06-01

279

Performance of HCFC22 alternative refrigerants  

SciTech Connect

In this study, 14 refrigerant mixtures composed of R32, R125, R134a, R152a, R290(Propane) and R1270(Propylene) were tested in a breadboard heat pump in an attempt to replace R22 used in residential air-conditioners. The test heat pump was of 1 ton capacity with water as the secondary heat transfer fluids. All tests were conducted under ARI test A condition. Test results how that ternary mixtures composed of R32, R125, and R134a have 4 {approximately} 5% higher coefficient of performance(COP) and capacity than R22. Hence they seem to be promising alternatives for R22. On the other hand, ternary mixtures containing R125, R134a, and R152a have lower COPs and capacities than R22. R290/R134 azeotrope also shows 3--4% increases in COP and capacity. The compressor discharge and dome temperatures of all the mixtures tested are lower than those of R22 by 15.9--34.7 C and 5.5--14.3 C respectively, indicating that these mixtures would offer better system reliability and longer life time than R22. Finally, the test results with a suction line heat exchanger (SLHX) indicated that SLHX must be used with special care in air-conditioners since its effect is fluid dependent.

Jung, D.; Kim, C.B.; Song, Y.J.; Park, B.J.

1999-07-01

280

Japanese activities in refrigeration technology  

NASA Astrophysics Data System (ADS)

This paper reviews recent activities in refrigeration technology in Japan. The projects described are stimulated by growing industrial needs or form part of large national projects. The JNR project on the MAGLEV train is currently the most powerful activity and it demands knowledge in all the different disciplines of cryogenics in particular on various scales of refrigeration. Research activities are also directed towards the development of Stirling cycle and magnetic refrigerators for applications in a wider area.

Fujita, T.; Ohtsuka, T.; Ishizaki, Y.

281

NICE3: Industrial Refrigeration System  

SciTech Connect

Energy Concepts has developed an absorption-augmented system as a cost-effective means of achieving more cooling capacity with a substantial reduction in energy consumption and greenhouse gas emissions for industrial refrigeration. It cuts fuel consumption by 30% by combining an internal combustion engine with a mechanical compression refrigeration system and an absorption refrigeration system. The absorption system is powered by engine waste heat. Conventional industrial refrigeration uses mechanical vapor compression, powered by electric motors, which results in higher energy costs. By the year 2010, the new system could cut fuel consumption by 19 trillion Btu and greenhouse emissions by more than 1 million tons per year.

Simon, P.

1999-09-29

282

63 FR 58767 - Refrigeration Compressors From Singapore  

Federal Register 2010, 2011, 2012, 2013

...701-TA-B (Review)] Refrigeration Compressors From Singapore AGENCY: United States...suspended investigation on refrigeration compressors from Singapore...suspended investigation on refrigeration compressors from Singapore would be likely to...

1998-11-02

283

49 CFR 173.174 - Refrigerating machines.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation...Class 1 and Class 7 § 173.174 Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg...

2012-10-01

284

49 CFR 173.174 - Refrigerating machines.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation...Class 1 and Class 7 § 173.174 Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg...

2010-10-01

285

49 CFR 173.174 - Refrigerating machines.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation...Class 1 and Class 7 § 173.174 Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg...

2013-10-01

286

49 CFR 173.174 - Refrigerating machines.  

...2014-10-01 2014-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation...Class 1 and Class 7 § 173.174 Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg...

2014-10-01

287

49 CFR 173.174 - Refrigerating machines.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation...Class 1 and Class 7 § 173.174 Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg...

2011-10-01

288

Sudden death involving inhalation of 1,1-difluoroethane (HFC-152a) with spray cleaner: three case reports.  

PubMed

Spray cleaner is a cleaning product containing compressed 1,1-difluoroethane (HFC-152a) to blow dust off electric devices and other sensitive equipment; however, it is also inhaled to induce euphoria. This report describes three cases of death involving HFC-152a inhalation with spray cleaner under different circumstances. In case 1, death was during inhalation for euphoria with which led to having frostbite. In case 2, death may have been associated with suicidal intention. Case 3 was also considered an accidental autoerotic death. In all three cases, HFC-152a was detected at 99.2-136.2mg/l in blood samples, 94.5-191.9 mg/l in urine samples and 3.6-18.4 mg in the gastric contents according to gas chromatography with flame ionization detection. To prevent death associated with HFC-152a inhalation from spray cleaner, the danger of the sudden death should be announced to people, given the ready availability of commercial products containing HFC-152a. PMID:20875935

Sakai, Kentaro; Maruyama-Maebashi, Kyoko; Takatsu, Akihiro; Fukui, Kenji; Nagai, Tomonori; Aoyagi, Miwako; Ochiai, Eriko; Iwadate, Kimiharu

2011-03-20

289

Investigations on two-phase heat exchanger for mixed refrigerant Joule-Thomson cryocooler  

NASA Astrophysics Data System (ADS)

The design of the recuperative heat exchanger used to pre-cool the refrigerant mixture prior to J-T expansion is crucial for the efficient operation of the mixed refrigerant Joule- Thomson (MR J-T) cryocooler. The multi-component non-azeotropic refrigerant mixture undergoes boiling and condensation heat transfer simultaneously in the heat exchanger. Therefore, it is important to analyze the performance of the heat exchanger in terms of temperature distribution with respect to the mixture of gases used. In the present work, temperature measurements are carried out at the ends of the heat exchanger for high pressure stream, while eight sensors are installed at equal distance along the length of heat exchanger to measure temperature of low pressure stream. The paper reports variation in heat transfer coefficient along the length of the heat exchanger. The variation is discussed with respect to temperature distribution across the length and changes in thermo-physical properties of the gas mixture.

Ardhapurkar, Purushottam; Sridharan, Arunkumar; Atrey, Milind

2012-06-01

290

Refrigerator-freezer energy testing with alternative refrigerants  

SciTech Connect

As a result of the Montreal Protocol that limits the production of ozone-depleting refrigerants, manufacturers are searching for alternatives to replace the R12 that is presently used in residential refrigerator-freezers. Before an alternative can be selected, several issues must be resolved. Among these are energy impacts, system compatibility, cost, and availability. In an effort to determine the energy impacts of some of the alternatives, energy consumption tests were performed in accordance with section 8 of the Association of Home Appliance Manufacturers (AHAM) standard for household refrigerators and household freezers. The results are presented for an 18 cubic foot (0.51 cubic meter), top-mount refrigerator-freezer with a static condenser using the following refrigerants: R12, R500, R12/Dimethyl-ether (DME), R22/R142b, and R134a. Conclusions from the AHAM test are that R500 and R12 /DME have a reduced energy consumption relative to R12 when replaced in the test unit with no modifications to the refrigeration system. Run times were slightly lower than R12 for both refrigerants indicating a higher capacity. While the R134a and R22/R142b results were less promising refrigeration system, such as a different capillary tube or compressor, may improve their performance. 12 refs., 2 figs., 3 tabs.

Vineyard, E.A.; Sand, J.R.; Miller, W.A.

1989-01-01

291

Field emission from single-crystalline HfC nanowires Jinshi Yuan, Han Zhang, Jie Tang, Norio Shinya, Kiyomi Nakajima et al.  

E-print Network

Field emission from single-crystalline HfC nanowires Jinshi Yuan, Han Zhang, Jie Tang, Norio Shinya emission from single-crystalline HfC nanowires Jinshi Yuan,1,2 Han Zhang,3 Jie Tang,1,2 Norio Shinya,1

Qin, Lu-Chang

292

The refrigerator revolution  

SciTech Connect

This article discusses how a simple, new technology threw the best-laid plans of the chemical and refrigerator industries into disarray-and provided a new perspective on how future environmental agreements can be reached. In recent years, a series of massive business mergers has mesmerized the industrial world. However in the early 1990s a German environmentalist, triggered global reprocussions in the wake of the mandate to phase out the use of ozone depleting substances. The economic and political background of this is explained in detail.

Ayres, E.; French, H.

1996-09-01

293

Cycling Joule Thomson refrigerator  

NASA Astrophysics Data System (ADS)

A symmetrical adsorption pump/compressor system having a pair of mirror image legs and a Joule Thomson expander, or valve, interposed between the legs thereof for providing a, efficient refrigeration cycle is described. The system further includes a plurality of gas operational heat switches adapted selectively to transfer heat from a thermal load and to transfer or discharge heat through a heat projector, such as a radiator or the like. The heat switches comprise heat pressurizable chambers adapted for alternate pressurization in response to adsorption and desorption of a pressurizing gas confined therein.

Tward, E.

1983-01-01

294

Superinsulation in refrigerators and freezers  

Microsoft Academic Search

The results presented here were obtained during Phase 4 of the first CRADA, which had the specific objective of determining the lifetime of superinsulations when installed in simulated refrigerator doors. The second CRADA was established to evaluate and test design concepts proposed to significantly reduce energy consumption in a refrigerator-freezer that is representative of approximately 60% of the US market.

E. Vineyard; T. K. Stovall; K. E. Wilkes; K. W. Childs

1998-01-01

295

The vapor compression refrigeration cycle  

Microsoft Academic Search

This article is a review of the basic principles of a cycle widely used to create the refrigeration effect that provides both human comfort and process cooling. While a semantic differentiation often is made for cooling and dehumidifying air for human comfort (air conditioning) and cooling for products and processes (refrigeration), all mechanical cooling applications depend on the previously mentioned

Pannkoke

1995-01-01

296

Atmospheric degradation mechanisms of hydrogen containing chlorofluorocarbons (HCFC) and fluorocarbons (HFC)  

NASA Technical Reports Server (NTRS)

The current knowledge of atmospheric degradation of hydrogen containing chlorofluorocarbons (HCFC 22 (CHClF2), HCFC 123 (CHCl2CF3), HCFC 124 (CHClFCF3), HCFC 141b (CFCl2CH3), HCFC 142b (CF2ClCH3)) and fluorocarbons (HFC 125 (CHF2CF3), HFC 134a (CH2FCF3), HFC 152a (CHF2CH3)) is assessed. Except for the initiation reaction by OH radicals, there are virtually no experimental data available concerning the subsequent oxidative breakdown of these molecules. However, from an analogy to the degradation mechanisms of simple alkanes, some useful guidelines as to the expected intermediates and final products can be derived. A noteable exception from this analogy, however, appears for the oxi-radicals. Here, halogen substitution induces new reaction types (C-Cl and C-C bond ruptures) which are unknown to the unsubstituted analogues and which modify the nature of the expected carbonyl products. Based on an evaluation of these processes using estimated bond strength data, the following simplified rules with regards to the chlorine content of the HCFC's may be deduced: (1) HCFC's containing one chlorine atom such as 22 and 142b seem to release their chlorine content essentially instantaneous with the initial attack on the parent by OH radicals, and for HCFC 124, such release is apparently prevented; (2) HCFC's such as 123 and 141b with two chlorine atoms are expected to release only one of these instantaneously; and the second chlorine atom may be stored in potentially long-lived carbonyl compounds such as CF3CClO or CClFO.

Zellner, Reinhard

1990-01-01

297

Helium dilution refrigeration system  

DOEpatents

A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains .sup.3 He and .sup.4 He liquids which are precooled by a coupled container containing .sup.3 He liquid, enabling the phase separation of a .sup.3 He rich liquid phase from a dilute .sup.3 He-.sup.4 He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the .sup.3 He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute .sup.3 He-.sup.4 He liquid phase.

Roach, Patrick R. (Darien, IL); Gray, Kenneth E. (Naperville, IL)

1988-01-01

298

Malone cycle refrigerator development  

SciTech Connect

This paper describes the progress made in demonstrating a Malone Cycle Refrigerator/Freezer. The Malone cycle is similar to the Stirling cycle but uses a supercritical fluid in place of real gas. In the approach, solid-metal diaphragms are used to seal and sweep the working volumes against the high working fluid pressures required in Malone cycle machines. This feature eliminates the friction and leakage that accounted for nearly half the losses in the best piston-defined Malone cycle machines built to date. The authors successfully built a Malone cycle refrigerator that: (1) used CO{sub 2} as the working fluid, (2) operated at pressures up to 19.3 Mpa (2,800 psi), (3) achieved a cold end metal temperatures of {minus}29 C ({minus}20 F), and (4) produced over 400 Watts of cooling at near ambient temperatures. The critical diaphragm components operated flawlessly throughout characterization and performance testing, supporting the conclusion of high reliability based on analysis of fatigue date and actual strain measurements.

Shimko, M.A.; Crowley, C.J.

1999-07-01

299

Development of jt Coolers Operating at Cryogenic Temperatures with Nonflammable Mixed Refrigerants  

NASA Astrophysics Data System (ADS)

Throttle cycle coolers, operating with mixed refrigerants have been already used at refrigeration temperatures down to 70 K. An industrial single-stage, oil lubricated compressor can be used to provide both, a relatively low cost and long operational time. Application of nonflammable mixed refrigerants is important for safety, transportation, service and maintenance. However, it is more difficult to provide a required refrigeration performance and long-term reliability due to properties of nonflammable components. The paper presents experimental and modeling data for single-stage coolers operating in a temperature range of 80 to 150 K. The nonflammable components were selected to develop mixed refrigerants for the desired temperature ranges. A gas refrigerant supply technology is used for a single-stage cooler design. The minimal achievable temperature is restricted by the freezing point of the mixture. Selected gas refrigerant technology restricts the maximal refrigeration capacity. However, it allows a compromise between stable, long-term reliable operation and simplicity of equipment design. Stability of operation of small-scale, highly reliable coolers has been proven by the data accumulated over more than one year of testing.

Khatri, A.; Boiarski, M.

2008-03-01

300

Comparative study of the performance of an ejector refrigeration cycle operating with various refrigerants  

Microsoft Academic Search

Ejector refrigeration systems have attracted many research activities in recent years. These systems traditionally operate with water as refrigerant with low COP values. Other refrigerants commonly used in mechanical vapour compression cycles may provide better performance for ejector refrigeration cycles. Eleven refrigerants, including water, halocarbon compounds (CFCs, HCFCs and HFCs), a cyclic organic compound, and an azeotrope, are chosen as

Da-Wen Sun

1999-01-01

301

Refrigerator: Refrigerators and freezers are not typically constructed to assure that there is no  

E-print Network

LAB SAFETY Refrigerator: Refrigerators and freezers are not typically constructed to assure temperature of the refrigerator rises. This results in an increase in the concentration of flammable vapors within the refrigerator's interior. When power is restored, a spark generated by the refrigerator light

Cohen, Robert E.

302

77 FR 7547 - Energy Conservation Standards for Wine Chillers and Miscellaneous Refrigeration Products: Public...  

Federal Register 2010, 2011, 2012, 2013

...standards/residential/refrigerators_freezers.html. DATES: DOE will...standards for refrigerators, refrigerator-freezers, and freezers (residential...1) Refrigerators and refrigerator-freezers with manual...

2012-02-13

303

HFC-43-10mee atmospheric abundances and global emission estimates  

NASA Astrophysics Data System (ADS)

report in situ atmospheric measurements of hydrofluorocarbon HFC-43-10mee (C5H2F10; 1,1,1,2,2,3,4,5,5,5-decafluoropentane) from seven observatories at various latitudes, together with measurements of archived air samples and recent Antarctic flask air samples. The global mean tropospheric abundance was 0.21 ± 0.05 ppt (parts per trillion, dry air mole fraction) in 2012, rising from 0.04 ± 0.03 ppt in 2000. We combine the measurements with a model and an inverse method to estimate rising global emissions—from 0.43 ± 0.34 Gg yr-1 in 2000 to 1.13 ± 0.31 Gg yr-1 in 2012 (~1.9 Tg CO2-eq yr-1 based on a 100 year global warming potential of 1660). HFC-43-10mee—a cleaning solvent used in the electronics industry—is currently a minor contributor to global radiative forcing relative to total HFCs; however, our calculated emissions highlight a significant difference from the available reported figures and projected estimates.

Arnold, Tim; Ivy, Diane J.; Harth, Christina M.; Vollmer, Martin K.; Mühle, Jens; Salameh, Peter K.; Paul Steele, L.; Krummel, Paul B.; Wang, Ray H. J.; Young, Dickon; Lunder, Chris R.; Hermansen, Ove; Rhee, Tae Siek; Kim, Jooil; Reimann, Stefan; O'Doherty, Simon; Fraser, Paul J.; Simmonds, Peter G.; Prinn, Ronald G.; Weiss, Ray F.

2014-03-01

304

Cryogenic refrigeration apparatus  

DOEpatents

A technique for producing a cold environment in a refrigerant system in which input fluid from a compressor at a first temperature is introduced into an input channel of the system and is pre-cooled to a second temperature for supply to one of at least two stages of the system, and to a third temperature for supply to another stage thereof. The temperatures at such stages are reduced to fourth and fifth temperatures below the second and third temperatures, respectively. Fluid at the fourth temperature from the one stage is returned through the input channel to the compressor and fluid at the fifth temperature from the other stage is returned to the compressor through an output channel so that pre-cooling of the input fluid to the one stage occurs by regenerative cooling and counterflow cooling and pre-cooling of the input fluid to the other stage occurs primarily by counterflow cooling.

Crunkleton, James A. (Cambridge, MA)

1992-01-01

305

Synopsis of residential refrigerator/freezer alternative refrigerants evaluation  

SciTech Connect

The experimental testing on residential refrigerator/freezers (R/Fs) is summarized in this paper. R/F testing focused on two areas: alternative refrigerants and equipment configurations. The refrigerants evaluated consisted of single components, azeotropes, and zeotropes derived from hydrofluorocarbons (HFCs) and hydrocarbons (HCs). These refrigerants were evaluated in conventional and unconventional R/F designs. Major and minor design modifications were studied. Minor modifications consisted of various capillary tube lengths, door insulations, and compressors, while major modifications included two-evaporator and two-cycle R/F systems. Results obtained from testing the two-cycle system will be discussed in a later paper. This paper presents the experimental results of alternative technologies evaluated as replacements for ozone depleting chemicals.

Baskin, E. [Environmental Protection Agency, Research Triangle Park, NC (United States)

1998-12-31

306

Refrigerator-freezer energy testing with alternative refrigerants  

Microsoft Academic Search

As a result of the Montreal Protocol that limits the production of ozone-depleting refrigerants, manufacturers are searching for alternatives to replace the R12 that is presently used in residential refrigerator-freezers. Before an alternative can be selected, several issues must be resolved. Among these are energy impacts, system compatibility, cost, and availability. In an effort to determine the energy impacts of

E. A. Vineyard; J. R. Sand; W. A. Miller

1989-01-01

307

Refrigerator-freezer energy testing with alternative refrigerants  

SciTech Connect

As a result of the Montreal Protocol (UNEP 1987) that limits the production of ozone-depleting refrigerants, manufacturers are searching for alternatives to replace the R12 that is presently used in residential refrigerator-freezers. Before an alternative can be selected, several issues must resolved. Among these are energy impacts, system compatibility, cost, and availability, In an effort to determine the energy impacts of some of the alternatives, energy consumption tests were performed in accordance with section 8 of the Association of Home Appliance Manufacturers (AHAM) standard for household refrigerators and household freezers (AHAM 1985). The results are presented for an 18 ft{sup 3} (0.51 m{sup 3}), top mount refrigerators-freezer with a static condenser using the following refrigerants: R 12, R500, R12/dimethylether (DME), R22/R142b, and R134a. Conclusions from the AHAM test are that R500 and R12/DME have a reduced energy consumption relative to R12 when replaced in the test unit with no modifications to the refrigeration system. Run times were slightly lower than R12 for both refrigerants, indicating a higher capacity. While the R134a and R22/R142b results were less promising (6.8% and 8.5% higher energy consumption, respectively), changes to the refrigeration system, such as a different capillary tube or compressor, may improve their performance. It is noted that the test results are only an initial step in determining a replacement for R12.

Sand, J.R. (Oak Ridge National Lab., Oak Ridge, TN (US)); Vineyard, E.A.; Sand, J.R.

1989-01-01

308

Near azeotropic mixture substitute for dichlorodifluoromethane  

NASA Technical Reports Server (NTRS)

A refrigerant and a process of formulating thereof that consists of a mixture of a first mole fraction of CH.sub.2 FCF.sub.3 and a second mole fraction of a component selected from the group consisting of a mixture of CHClFCF.sub.3 and CH.sub.3 CClF.sub.2 ; a mixture of CHF.sub.2 CH.sub.3 and CH.sub.3 CClF.sub.2 ; and a mixture of CHClFCF.sub.3, CH.sub.3 CClF.sub.2 and CHF.sub.2 CH.sub.3.

Jones, Jack A. (Inventor)

1998-01-01

309

PERFORMANCE TESTING OF A SEMI-HERMETIC COMPRESSOR WITH HFC-236EA AND CFC-114 AT CHILLER CONDITIONS  

EPA Science Inventory

The paper gives results of tests of both HFC-236ea and CFC-114 at a range of temperatures covering surface craft and submarine chiller conditions. vaporating temperatures ranged from 1.7 to 12.8 C, and condensing temperatures from 40.6 to 65.6 C, in order to develop a nine-point ...

310

Energy Efficient, Environmentally Friendly Refrigerants  

E-print Network

This paper describes a new family of safe, environmentally friendly, high performance substitute refrigerants for application in manufacturing and facilities operations. Due to the Montreal Protocol and subsequent environmental regulations, CFC...

Nimitz, J.; Glass, S.; Dhooge, P. M.

311

Control system for thermoelectric refrigerator  

NASA Technical Reports Server (NTRS)

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).

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

1996-01-01

312

Inert hydrocarbon-based refrigerants  

Microsoft Academic Search

This paper determines the flammability properties of two hydrocarbon blends, natural gas and propane–butane refrigerant, mixed with CF3I and C3F7H inerting agents. Four flammability envelopes are obtained allowing the determination of the minimum inerting concentrations and the maximum hydrocarbon to suppressant weight ratios for formulating non-flammable hydrocarbon refrigerants. These ratios are calculated from the slopes of lines drawn from the

B. Z. Dlugogorski; R. K. Hichens; E. M. Kennedy

2002-01-01

313

Predicting the viscosity of halogenated hydrocarbon mixtures  

Microsoft Academic Search

The viscosity of three refrigerant mixtures, namely R125–R134a, R152a–R134a and propane–R134a, has been evaluated by a prediction method based on kinetic theory. The method has no adjustable parameters and, in essence, relies upon knowledge of the viscosity of the pure components to predict the viscosity of a mixture by means of rigid-sphere formalism. The predictions have been compared with experimental

V. Vesovic

2002-01-01

314

Initial parametric results using CYCLEZ---An LMTD-specified, Lorenz-Meutzner cycle refrigerator-freezer model  

SciTech Connect

A computer model representing a two-evaporator, two-intercooler refrigerator-freezer operating at steady-state with nonazeotropic refrigerant mixtures (CYCLEZ) has been developed at Oak Ridge National Laboratory (ORNL). This model is being used to assess the effects of system design and operating parameters on the cycle performance of a refrigerator-freezer designed around the Lorenz- Meutzner (L-M) circuit. Separate evaporators for the freezer and fresh-food compartments are modeled, as well as two intercoolers that subcool liquid refrigerant from the condenser by heat transfer with low-pressure refrigerant. The CYCLEZ refrigerator/freezer model is derived form the CYCLEZ heat-pump model developed originally by the National Institute of Standards and Technology (NIST). CYCLEZ currently uses the Carnahan-Starling-DeSantis (CSD) equation-of-state to compute refrigerant thermodynamic properties , so that new refrigerants can easily be added. Condenser and evaporator heat-exchanger performance are defined by user-specified overall LMTDs which allow equivalent heat-exchanger sizing per unit refrigeration load to be maintained for different refrigerant mixtures. A more consistent formulation of overall heat-exchanger LMTD is applied across the condenser superheated and two-phase regions as well as over the two evaporators. Source and sink conditions are specified in terms of inlet and outlet temperatures of the external fluid streams. Intercooler high-side (subcooling) {delta} Ts and relative fresh-food-to-freezer load ratio are also user-specified. These features make this model well suited for evaluating the optimal thermodynamic cycle requirements of the five heat exchangers used in the L-M refrigerator/freezer circuit. 13 refs., 6 figs., 1 tab.

Rice, C.K.; Sand, J.R.

1990-01-01

315

Auto defrost refrigerator  

SciTech Connect

A refrigerator is described including: an upper freezer compartment, a lower fresh food compartment and an insulating partition separating the compartments; an evaporator chamber separate from the freezer and fresh food compartment and above the fresh food compartment; means for conducting relatively cold air from the chamber to the freezer compartment and means for conducting relatively cold air from the chamber to the fresh food compartment; return means for returning relatively warm air from the freezer compartment to the chamber; duct means connecting the lower portion of the fresh food compartment with the chamber for returning relative warm air from the fresh food compartment to the chamber; evaporator means, including a first evaporator section positioned in the evaporator chamber and a second evaporator section positioned in the duct means, for cooling air passing thereover; and fan means for withdrawing relatively warm air from the compartments, circulating the air from the freezer compartment over the first evaporator section, circulating the air from the fresh food compartment serially over both the second and first evaporator sections and discharging cooled air from the evaporator chamber.

Schulze, J.L.

1988-05-03

316

Performance Analysis of the Absorption Refrigeration Cycle using TFE/NMP as a Working Fluid  

NASA Astrophysics Data System (ADS)

Performance analysis was made for the absorption refrigeration cycle using TFE/NMP as a working fluid. In the calculation the steady states model, and the separation and mixture of refrigerant model were constructed. The experimental equipment of the absorption refrigeration cycle was also manufactured. The calculation model and the experimental equipment consisted of the generator, the condenser, the evaporator, the absorber, the partial condenser, the rectifier, the reservoir, the heat recovery heat exchanger, the solution pump and the expansion valve. The reservoir was used to store the liquid refrigerant for changing the solution concentration in the cycle. The calculation and experimental results showed the agreement at the lower generation temperature, but presented the opposite trend because of the influence of the heat release in the partial condenser. The calculation and experimental results showed the good agreement for the separation and mixture of refrigerant process. In results, it was found that this absorption refrigeration cycle using TFE/NMP as a working fluid had possibility to utilize recovering the wide range waste heat to energy.

Kato, Masashi; Tsujimori, Atsushi; Morita, Hajime

317

Modelling of a refrigerating system coupled with a refrigerated room  

NASA Astrophysics Data System (ADS)

The development of a set of comprehensive computer models to simulate and analyze both steady state and non steady state behavior of a refrigerating system coupled with a refrigerated room is described. The refrigerating system is a single stage vapor compression system consisting of four basic elements: a reciprocating piston compressor, a dry expansion evaporator (or cooler), a shell and tube watercooled condensor and a thermostatic expansion valve. To validate the computer models, a test plant on which steady state and dynamic measurements were carried out, was set up. Experiments to determine several empirical constants encountered in the models were done, and the simulation results were compared with a series of measurements within a wide range of operation conditions. The validated models were applied to the prediction of the air distributions in a cold store and the study of a system with different capacity control systems, proving the capability and reliability of the models.

Wang, Hongwei

1991-08-01

318

Superinsulation in refrigerators and freezers  

SciTech Connect

The results presented here were obtained during Phase 4 of the first CRADA, which had the specific objective of determining the lifetime of superinsulations when installed in simulated refrigerator doors. The second CRADA was established to evaluate and test design concepts proposed to significantly reduce energy consumption in a refrigerator-freezer that is representative of approximately 60% of the US market. The stated goal of this CRADA is to demonstrate advanced technologies which reduce, by 50%, the 1993 National Appliance Energy Conservation Act (NAECA) standard energy consumption for a 20 ft{sup 3} (570 L) top-mount, automatic-defrost, refrigerator-freezer. For a unit this size, the goal translates to an energy consumption of 1.003 kWh/d. The general objective of the research is to facilitate the introduction of efficient appliances by demonstrating design changes that can be effectively incorporated into new products. In previous work on this project, a Phase 1 prototype refrigerator-freezer achieved an energy consumption of 1.413 kWh/d [Vineyard, et al., 1995]. Following discussions with an advisory group comprised of all the major refrigerator-freezer manufacturers, several options were considered for the Phase 2 effort, one of which was cabinet heat load reductions.

Vineyard, E.; Stovall, T.K.; Wilkes, K.E.; Childs, K.W.

1998-02-01

319

Observations of 1,1-difluoroethane (HFC152a) at AGAGE and SOGE monitoring stations in 1994-2004 and derived global and regional emission estimates  

Microsoft Academic Search

Ground-based in situ measurements of 1,1-difluoroethane (HFC-152a, CH3CHF2) which is regulated under the Kyoto Protocol are reported under the auspices of the AGAGE (Advanced Global Atmospheric Gases Experiment) and SOGE (System of Observation of halogenated Greenhouse gases in Europe) programs. Observations of HFC-152a at five locations (four European and one Australian) over a 10 year period were recorded. The annual

B. R. Greally; A. J. Manning; S. Reimann; A. McCulloch; J. Huang; B. L. Dunse; P. G. Simmonds; R. G. Prinn; P. J. Fraser; D. M. Cunnold; S. O'Doherty; L. W. Porter; K. Stemmler; M. K. Vollmer; C. R. Lunder; N. Schmidbauer; O. Hermansen; J. Arduini; P. K. Salameh; P. B. Krummel; R. H. J. Wang; D. Folini; R. F. Weiss; M. Maione; G. Nickless; F. Stordal; R. G. Derwent

2007-01-01

320

Krypton based adsorption type cryogenic refrigerator  

NASA Technical Reports Server (NTRS)

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

Jones, Jack A. (inventor); Schember, Helene (inventor)

1987-01-01

321

Krypton based adsorption type cryogenic refrigerator  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

322

Thermoelectric refrigerator having improved temperature stabilization means  

DOEpatents

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.

Falco, Charles M. (Woodridge, IL)

1982-01-01

323

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...

324

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, ...

325

Energy Saving with Absorption Refrigeration Technologies  

E-print Network

ENERGY SAVING WITH ABSORPTION REFRIGERATION TECHNOLOGIES Richard C. Davis Carrier International Corporation Syracuse, New York ABSTRACT Absorption refrigeration technology can be an economical and cost effective means of reducing energy...

Davis, R. C.

1984-01-01

326

M. Bahrami ENSC 461 (S 11) Refrigeration Cycle 1 Refrigeration Cycle  

E-print Network

-1 involves expansion of two-phase flow in a turbine. The Ideal VaporCompression Refrigeration Cycle The vapor-compression refrigeration is the most widely used cycle for refrigerators, air- conditioners, and heat pumps. Fig. 5-2: Schematic for ideal vapor-compression refrigeration cycle. Assumptions for ideal

Bahrami, Majid

327

Acoustic impedance measurements of pulse tube refrigerators  

NASA Astrophysics Data System (ADS)

Complex acoustic impedance is determined in a prototype refrigerator that can mimic orifice-type, inertance-type, and double inlet-type pulse tube refrigerators from simultaneous measurements of pressure and velocity oscillations at the cold end. The impedance measurements revealed the means by which the oscillatory flow condition in the basic pulse tube refrigerator is improved by additional components such as a valve and a tank. The working mechanism of pulse tube refrigerators is explained based on an electrical circuit analogy.

Iwase, Takashi; Biwa, Tetsushi; Yazaki, Taichi

2010-02-01

328

Pot-in-Pot Refrigeration  

NSDL National Science Digital Library

In this activity (on page 2 of PDF), learners create a low-tech refrigerator that requires no electricity to keep food from spoiling. It uses only clay pots, one smaller than the other and separated by wet sand. As the water evaporates from the sand, it lowers the temperature inside the inner pot, similar to how evaporation from a sweaty person lowers the person's body temperature. This "refrigerator" with no moving parts is great for exploring evaporative cooling, as well as scientific innovation, especially since it has been used successfully in Africa.

Omsi

2004-01-01

329

Ternary Dy-Er-Al magnetic refrigerants  

DOEpatents

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.

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

1995-07-25

330

Ternary Dy-Er-Al magnetic refrigerants  

DOEpatents

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.

Gschneidner, Jr., Karl A. (Ames, IA); Takeya, Hiroyuki (Ibaraki, JP)

1995-07-25

331

Solar Refrigerators Store Life-Saving Vaccines  

NASA Technical Reports Server (NTRS)

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.

2014-01-01

332

Method and apparatus for desuperheating refrigerant  

DOEpatents

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.

Zess, James A. (Kelso, WA); Drost, M. Kevin (Richland, WA); Call, Charles J. (Richland, WA)

1997-01-01

333

Conversion of centrifugal chillers to alternate refrigerants  

Microsoft Academic Search

The discovery of the adverse effect of certain chloroflourocarbon refrigerants on the upper atmosphere brought about the need to eliminate the offending refrigerants and replace them with those that are environmentally friendly. The use of a refrigerant different from that used in the original design of a centrifugal chiller creates issues of capacity, efficiency and reliability. The scope of the

G. E. Roark

1995-01-01

334

Ideal orifice pulse tube refrigerator performance  

NASA Technical Reports Server (NTRS)

The recent development of orifice pulse tube refrigerators has raised questions as to what limits their ultimate performance. Using an analogy to the Stirling cycle refrigerator, the efficiency (cooling power per unit input power) of an ideal orifice pulse tube refrigerator is shown to be T1/T0, the ratio of the cold temperature to the hot temperature.

Kittel, P.

1992-01-01

335

Ideal orifice pulse tube refrigerator performance  

Microsoft Academic Search

The recent development of orifice pulse tube refrigerators has raised questions as to what limits their ultimate performance. Using an analogy to the Stirling cycle refrigerator, the efficiency (cooling power per unit input power) of an ideal orifice pulse tube refrigerator is shown to be T1\\/T0, the ratio of the cold temperature to the hot temperature.

P. Kittel

1992-01-01

336

World trade of refrigerators and freezers  

Microsoft Academic Search

This market research provides an overview of the world trade of refrigerators and freezers, with data at world-wide level and data on the evolution of appliances trade in 60 countries (selected according to their contribution to international trade of refrigerators and freezers). Data on production and consumption in quantity are included for each of the 60 countries.The growth of refrigerators

Aurelio Volpe; Stefania Pelizzari; Donatella Cheri

2007-01-01

337

78 FR 53374 - Energy Conservation Program for Consumer Products: Test Procedures for Refrigerators...  

Federal Register 2010, 2011, 2012, 2013

...Procedures for Refrigerators, Refrigerator-Freezers, and Freezers AGENCY...procedures for refrigerators, refrigerator-freezers, and freezers in the Federal...procedures for refrigerators, refrigerator-freezers, and freezers and...

2013-08-29

338

Technical Trend of Refrigeration System using Natural Working Fluids  

NASA Astrophysics Data System (ADS)

Technical trend of refrigeration system using natural refrigerants (or natural working fluids) was generally overviewed mainly by the proceedings of the International Conference of Natural Working Fluids past these few years. Hydrocarbon, carbon dioxide, water and air are mainly used as new refrigerants. Risk assessment of these flammable refrigerants was widely discussed. Hydrocarbon has been already widely used for refrigerators in Germany. Carbon-dioxide is now focused as a new refrigerant for air-conditioners of automobiles and water heaters. Turbo chiller with water as refrigerant has been tested in Germany. Air cycle refrigeration systems were applied to commercial freezer and for transportation. Natural refrigerants are also paid attention as secondary refrigerants.

Hara, Toshitsugu

339

Measurements of HFC-134a and HCFC-22 in groundwater and unsaturated-zone air: implications for HFCs and HCFCs as dating tracers  

USGS Publications Warehouse

A new analytical method using gas chromatography with an atomic emission detector (GC–AED) was developed for measurement of ambient concentrations of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) in soil, air, and groundwater, with the goal of determining their utility as groundwater age tracers. The analytical detection limits of HCFC-22 (difluorochloromethane, CHClF2) and HFC-134a (1,2,2,2-tetrafluoroethane, C2H2F4) in 1 L groundwater samples are 4.3 × 10? 1 and 2.1 × 10? 1 pmol kg? 1, respectively, corresponding to equilibrium gas-phase mixing ratios of approximately 5–6 parts per trillion by volume (pptv). Under optimal conditions, post-1960 (HCFC-22) and post-1995 (HFC-134a) recharge could be identified using these tracers in stable, unmixed groundwater samples. Ambient concentrations of HCFC-22 and HFC-134a were measured in 50 groundwater samples from 27 locations in northern and western parts of Virginia, Tennessee, and North Carolina (USA), and 3 unsaturated-zone profiles were collected in northern Virginia. Mixing ratios of both HCFC-22 and HFC-134a decrease with depth in unsaturated-zone gas profiles with an accompanying increase in CO2 and loss of O2. Apparently, ambient concentrations of HCFC-22 and HFC-134a are readily consumed by methanotrophic bacteria under aerobic conditions in the unsaturated zone. The results of this study indicate that soils are a sink for these two greenhouse gases. These observations contradict the previously reported results from microcosm experiments that found that degradation was limited above-ambient HFC-134a. The groundwater HFC and HCFC concentrations were compared with concentrations of chlorofluorocarbons (CFCs, CFC-11, CFC-12, CFC-113) and sulfur hexafluoride (SF6). Nearly all samples had measured HCFC-22 or HFC-134a that were below concentrations predicted by the CFCs and SF6, with many samples showing a complete loss of HCFC-22 and HFC-134a. This study indicates that HCFC-22 and HFC-134a are not conservative as environmental tracers and leaves in question the usefulness of other HCFCs and HFCs as candidate age tracers.

Haase, Karl B.; Busenberg, Eurybiades; Plummer, L. Niel; Casile, Gerolamo; Sanford, Ward E.

2014-01-01

340

Solar-Powered Refrigeration System  

NASA Astrophysics Data System (ADS)

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.

Ewert, Michael K.; Bergeron, David J., III

2002-10-01

341

Performance modeling of optical refrigerators  

Microsoft Academic Search

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

Gary Mills; Allan Mord

2006-01-01

342

Solar-Powered Refrigeration System  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

343

Solar-Powered Refrigeration System  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

344

Model Based Control Refrigeration Systems  

E-print Network

Model Based Control of Refrigeration Systems Ph.D. Thesis Lars Finn Sloth Larsen Central R & D Sloth Larsen Printing: Budolfi tryk Aps #12;To my wife Helena #12;#12;Preface and Acknowledgments and Innovation and Danfoss A/S. November 2005, Nordborg, Denmark Lars Finn Sloth Larsen v #12;#12;Summary

345

Low-temperature magnetic refrigerator  

DOEpatents

The disclosure is directed to a low temperature 4 to 20 K. refrigeration apparatus and method utilizing a ring of magnetic material moving through a magnetic field. Heat exchange is accomplished in and out of the magnetic field to appropriately utilize the device to execute Carnot and Stirling cycles.

Barclay, John A. (Los Alamos, NM)

1985-01-01

346

Measures to Control Forming of Oil in a Refrigerant Compressor  

NASA Astrophysics Data System (ADS)

Foaming of lubricating oil in a rotary compressor induces flowing out of the oil from the compressor, which deteriorates reliability of the compressor. This study investigates foaming characteristics of oil-refrigerant mixture by using an experimental apparatus which models foaming in the compressor. The experiments reveal that the foaming caused by blade rotation can be controlled by a plate which prevents a vortex from swallowing up the vapor and that the foaming caused by vapor blow can be depressed by a blow pipe extending above the mixture. Based on these results, measures to control foaming in a practical rotary compressor are investigated by using an experimental refrigerating cycle. From measurement of the foaming, it is proved that a simple cover which separates discharge blow from the mixture under a motor has a great effect of defoaming. Collection of oil which is pumped up through a shaft is also effective in decreasing the foaming. In addition, improvement of transient performance of the cycle is obtained by controlling the foaming.

Yanagisawa, Tadashi; Shimizu, Takashi; Fukuta, Mitsuhiro; Mizuno, Yoshihito

347

Application of magnetic refrigeration and its assessment  

NASA Astrophysics Data System (ADS)

Magnetic refrigeration has the potential to replace conventional refrigeration—with often problematic refrigerants—in several niche markets or even some main markets of the refrigeration domain. Based on this insight, for the Swiss Federal Office of Energy a list of almost all existing refrigeration technologies was worked out. Then an evaluation how good magnetic refrigeration applies to each of these technologies was performed. For this purpose a calculation tool to determine the coefficient of performance ( COP) and the exergy efficiency as a function of the magnetic field strength and the rotation frequency of a rotary-type magnetic refrigerator was developed. The evaluation clearly shows that some application domains are more ideal for a replacement of conventional refrigerators by their magnetic counterparts than others. In the pre-study, four good examples were chosen for a more comprehensive investigation and working out of more detailed results. In this article, the calculation method is briefly described. COP values and exergy efficiencies of one very suitable technology, namely the magnetic household refrigerator, are presented for different operation conditions. Summarizing, it is stated that magnetic refrigeration is a serious environmentally benign alternative to some conventional cooling, refrigeration and air-conditioning technologies.

Kitanovski, Andrej; Egolf, Peter W.

2009-04-01

348

Demand Side Management (DSM) Through Absorption Refrigeration Systems  

E-print Network

to generate required refrigeration, is also an ideal solution to both reducing the industrial waste heat and to replace the CFC refrigerant operated mechanical driven refrigeration system. The concept of using waste heat for absorption refrigeration... refrigeration potential will be illustrated by two recent case studies. INTRODUCTION This paper deals with a Demand Side Management (DSM) option of using waste heat for refrigeration. Absorption Refrigeration from waste heat offers a viable option for DSM...

Chao, P. Y.; Shukla, D.; Amarnath, A.; Mergens, E.

349

Shear viscosity of binary mixtures: The Gay-Berne potential  

NASA Astrophysics Data System (ADS)

The Gay-Berne (GB) potential model is an interesting and useful model to study the real systems. Using the potential model, we intend to examine the thermodynamical properties of some anisotropic binary mixtures in two different phases, liquid and gas. For this purpose, we apply the integral equation method and solve numerically the Percus-Yevick (PY) integral equation. Then, we obtain the expansion coefficients of correlation functions to calculate the thermodynamical properties. Finally, we compare our results with the available experimental data [e.g., HFC-125 + propane, R-125/143a, methanol + toluene, benzene + methanol, cyclohexane + ethanol, benzene + ethanol, carbon tetrachloride + ethyl acetate, and methanol + ethanol]. The results show that the GB potential model is capable for predicting the thermodynamical properties of binary mixtures with acceptable accuracy.

Khordad, R.

2012-05-01

350

Evaluation on environment-friendly refrigerants with similar normal boiling points in ejector refrigeration system  

NASA Astrophysics Data System (ADS)

Based on the "hypothetical throat area" theory and the "constant-pressure mixing" theory, a thermodynamic model for ejector was set up by introducing the real properties of refrigerants. Refrigerants which have similar normal boiling points with each other may act as replacement to each other in substitute progress. In this paper, eight environment-friendly refrigerants were divided into 4 pairs for study according to their normal boiling point. In each refrigerant pair, the entrainment ratios of ejector, system COP, pump power et al. of refrigerants were compared and analyzed. Lastly, the performances of the transcritical and subcritical ejector refrigeration cycles with propylene were calculated and compared.

Wang, F.; Shen, S. Q.; Li, D. Y.

2014-12-01

351

Synchronized discrete multitone: a bandwidth-efficient solution for the upstream channel of an HFC system  

NASA Astrophysics Data System (ADS)

Discrete multitone (DMT) has been accepted as a very effective modulation technique for point-to-point transmission on a channel whose SNR is highly frequency-dependent, and it has been adopted by ANSI as the standard for ADSL [up to 7 Mbit/s on unshielded twisted- pair (UTP)]. Synchronized DMT (SDMT), a variation of DMT for multipoint-to-point transmission, will be proposed to the ATIS committee T1E1.4 for VDSL (up to 51.8 Mbit/s on hybrid fiber/UTP), and to the IEEE committee 802.14 for the upstream channel of an HFC system. This paper describes the method of synchronization, which allows the efficient combination of signals from multiple transmitters without the use of guard bands in either the frequency- or time-domain. It also describes a protocol for controlling access to the shared channel by these transmitters, which may have widely varying needs for data rates and formats.

Bingham, John A.

1995-11-01

352

Dilution Refrigerator for Nuclear Refrigeration and Cryogenic Thermometry Studies  

NASA Astrophysics Data System (ADS)

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.

Nakagawa, Hisashi; Hata, Tohru

2014-07-01

353

Separating Mixtures  

NSDL National Science Digital Library

Students learn how to classify materials as mixtures, elements or compounds and identify the properties of each type. The concept of separation of mixtures is also introduced since nearly every element or compound is found naturally in an impure state such as a mixture of two or more substances, and it is common that chemical engineers use separation techniques to separate mixtures into their individual components. For example, the separation of crude oil into purified hydrocarbons such as natural gas, gasoline, diesel, jet fuel and/or lubricants.

2014-09-18

354

Quantum-enhanced absorption refrigerators  

E-print Network

Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators.

Luis A. Correa; José P. Palao; Daniel Alonso; Gerardo Adesso

2014-02-05

355

Quantum-enhanced absorption refrigerators.  

PubMed

Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators. PMID:24492860

Correa, Luis A; Palao, José P; Alonso, Daniel; Adesso, Gerardo

2014-01-01

356

Quantum-enhanced absorption refrigerators  

PubMed Central

Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators. PMID:24492860

Correa, Luis A.; Palao, José P.; Alonso, Daniel; Adesso, Gerardo

2014-01-01

357

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

ERIC Educational Resources Information Center

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…

Carey, John

358

Control method for mixed refrigerant based natural gas liquefier  

Microsoft Academic Search

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

Kenneth J. Kountz; Patrick M. Bishop

2003-01-01

359

Dual mixed refrigerant natural gas liquefaction with staged compression  

Microsoft Academic Search

An apparatus and process for liquefying natural gas using two closed-cycle, multicomponent refrigerants; a low level refrigerant which cools the natural gas and a high level refrigerant which cools the low level refrigerant wherein the improvement comprises phase separating the high level refrigerant after compression and fully liquefying the vapor phase stream against external cooling fluid after additional compression.

1985-01-01

360

Suction muffler for refrigeration compressor  

DOEpatents

A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell.

Nelson, Richard T. (Worthington, OH); Middleton, Marc G. (West Jefferson, OH)

1983-01-01

361

Suction muffler for refrigeration compressor  

DOEpatents

A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell. 5 figs.

Nelson, R.T.; Middleton, M.G.

1983-01-25

362

Magnetic refrigerator for hydrogen liquefaction  

NASA Astrophysics Data System (ADS)

This paper reviews the status of magnetic refrigeration system for hydrogen liquefaction. There is no doubt that hydrogen is one of most important energy sources in the near future. In particular, liquid hydrogen can be utilized for infrastructure construction consisting of storage and transportation. When we compare the consuming energy of hydrogen liquefaction with high pressurized hydrogen gas, FOM must be larger than 0.57 for hydrogen liquefaction. Thus, we need to develop a highly efficient liquefaction method. Magnetic refrigeration using the magneto-caloric effect has potential to realize not only the higher liquefaction efficiency >50%, but also to be environmentally friendly and cost effective. Our hydrogen magnetic refrigeration system consists of Carnot cycle for liquefaction stage and AMR (active magnetic regenerator) cycle for precooling stages. For the Carnot cycle, we develop the high efficient system with >80% liquefaction efficiency by using the heat pipe. For the AMR cycle, we studied two kinds of displacer systems, which transferred the working fluid. We confirmed the AMR effect with the cooling temperature span of 12 K for 1.8 T of the magnetic field and 6 s of the cycle. By using the simulation, we estimate the efficiency of the hydrogen liquefaction plant for 10 kg/day. A FOM of 0.47 is obtained for operation temperature between 20 K and 77 K including LN2 work input.

Numazawa, T.; Kamiya, K.; Utaki, T.; Matsumoto, K.

2014-07-01

363

Air-source heat pump carbon footprints: HFC impacts and comparison to other heat sources  

Microsoft Academic Search

European governments see that heat pumps could reduce carbon emissions in space- and hot-water heating. EU’s Renewable Energy Directive designates heat pumps as renewable – eligible for various subsidies – if their carbon footprints are below an implied, average threshold. This threshold omits carbon generated by manufacture and emission of a heat-pump’s fluorocarbon refrigerant. It also omits the footprint of

Eric P. Johnson

2011-01-01

364

Solid-vapor adsorption refrigeration system development  

NASA Astrophysics Data System (ADS)

The study describes the development of heat-activated industrial refrigeration systems using ammoniated complex compound sorption media. The focus was on single-stage cycles for low temperature (+20 F and below) refrigeration. Compared to vapor compression refrigeration, these cycles have the advantages of lower operating energy costs, reduction of peak electrical demand and associated demand charges, and reduced maintenance costs due to replacement of the compressor with solid-state sorbers. In many cases, particularly for refrigeration at -40 F and below, complex compound sorption cycles also have the potential for lower first cost than conventional electrically driven refrigeration systems. Technical issues addressed included the following: economic optimization of sorber design, demonstration of cyclic stability of the sorption reactions, construction material compatibility, and reactor scale-up. Sorption reactions for refrigeration at -40 and -70 F were demonstrated. Optimum heat exchanger configuration, complex compound loading, and cycle time were determined.

Rockenfeller, U.; Kirol, L.; Graebel, B.

1991-12-01

365

Compatibility of refrigerants and lubricants with elastomers  

SciTech Connect

Information contained in this reporters 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. Swell measurements have been made on approximately 50% of the proposed elastomers (94 total)in both the lubricant (7 total) and refrigerant (10 total) materials. Swell behavior in the these fluids have 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 hours and 24 hours for samples removed from the refrigerant test fluids and 24 hours after removal from the lubricants.

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

1992-07-01

366

40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant  

Code of Federal Regulations, 2010 CFR

...Analysis in Design (Design FMEA), Potential Failure Mode and Effects Analysis in Manufacturing and...Failure Mode and Effects Analysis for Machinery (Machinery...shall be applied to the design and development of service...not exceed 80% of the tank's rated volume at...

2010-07-01

367

40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant  

Code of Federal Regulations, 2012 CFR

40 Protection of Environment 18 2012-07-01...82 Protection of Environment ENVIRONMENTAL PROTECTION...Standard or allow for recycling of the recovered...Equipment and Recovery/Recycling/Recharging for Mobile...automotive service garage environment as defined in...

2012-07-01

368

40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant  

Code of Federal Regulations, 2013 CFR

40 Protection of Environment 18 2013-07-01...82 Protection of Environment ENVIRONMENTAL PROTECTION...Standard or allow for recycling of the recovered...Equipment and Recovery/Recycling/Recharging for Mobile...automotive service garage environment as defined in...

2013-07-01

369

40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant  

Code of Federal Regulations, 2011 CFR

40 Protection of Environment 17 2011-07-01...82 Protection of Environment ENVIRONMENTAL PROTECTION...Standard or allow for recycling of the recovered...Equipment and Recovery/Recycling/Recharging for Mobile...automotive service garage environment as defined in...

2011-07-01

370

40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant  

40 Protection of Environment 18 2014-07-01...82 Protection of Environment ENVIRONMENTAL PROTECTION...Standard or allow for recycling of the recovered...Equipment and Recovery/Recycling/Recharging for Mobile...automotive service garage environment as defined in...

2014-07-01

371

Manganese Nitride Sorption Joule-Thomson Refrigerator  

NASA Technical Reports Server (NTRS)

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.

Jones, Jack A.; Phillips, Wayne M.

1992-01-01

372

Environmental Fate of the Next Generation Refrigerant 2,3,3,3-Tetrafluoropropene (HFO-1234yf).  

PubMed

The hydrofluoroolefin 2,3,3,3-tetrafluoropropene (HFO-1234yf) has been introduced to replace 1,1,1,2-tetrafluoroethane (HFC-134a) as refrigerant in mobile, including vehicle, air conditioning systems because of its lower global warming potential. HFO-1234yf is volatile at ambient temperatures; however, high production volumes and widespread handling are expected to release this fluorocarbon into terrestrial and aquatic environments, including groundwater. Laboratory experiments explored HFO-1234yf degradation by (i) microbial processes under oxic and anoxic conditions, (ii) abiotic processes mediated by reactive mineral phases and zerovalent iron (Fe(0), ZVI), and (iii) cobalamin-catalyzed biomimetic transformation. These investigations demonstrated that HFO-1234yf was recalcitrant to microbial (co)metabolism and no transformation was observed in incubations with ZVI, makinawite (FeS), sulfate green rust (GRSO4), magnetite (Fe3O4), and manganese oxide (MnO2). Sequential reductive defluorination of HFO-1234yf to 3,3,3-trifluoropropene and 3,3-dichloropropene with concomitant stoichiometric release of fluoride occurred in incubations with reduced cobalamins (e.g., vitamin B12) indicating that biomolecules can transform HFO-1234yf at circumneutral pH and at ambient temperature. Taken together, these findings suggest that HFO-1234yf recalcitrance in aquifers should be expected; however, HFO-1234yf is not inert and a biomolecule may mediate reductive transformation in low redox environments, albeit at low rates. PMID:25329364

Im, Jeongdae; Walshe-Langford, Gillian E; Moon, Ji-Won; Löffler, Frank E

2014-11-18

373

Development of a novel refrigeration system for refrigerated trucks incorporating phase change material  

Microsoft Academic Search

An innovative refrigeration system incorporating phase change material (PCM) is proposed to maintain refrigerated trucks at the desired thermal conditions. The advantage of using PCM to maintain low temperatures is that a conventional refrigeration system does not have to be located on-board the vehicle. In addition, the system consumes less energy and produces much lower local greenhouse gas (GHG) emissions.

Ming Liu; Wasim Saman; Frank Bruno

2012-01-01

374

GEA Refrigeration Technologies / GEA Refrigeration Germany GmbH Wolfgang Dietrich / Dr. Ole Fredrich  

E-print Network

efficiency Recommended applications Screw and piston compressor based heat pumps #12;GEA Refrigeration ammonia Type of use chiller & heat pump Compressor Expansion valve Refrigerant Evaporator Condenser Qe Motor Qoc Oil-cooler (screws) Desuperheater Qd #12;GEA Refrigeration Technologies10 Achema 2012

Oak Ridge National Laboratory

375

Zeotropic mixtures of halocarbons as working fluids in binary geothermal power generation cycles  

Microsoft Academic Search

The performance of Rankine cycle binary systems for geothermal power generation using a hydrothermal resource has been investigated. To date, in addition to many pure fluids, mixtures of Paraffin-type hydrocarbons and water-ammonia mixtures have been investigated. This paper gives the results of consideration of mixtures of halocarbons as working fluids in these power cycles. The performance of mixtures of Refrigerant-114

Bliem

1987-01-01

376

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...

377

49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.  

...2014-10-01 2014-10-01 false Hydrogen chloride, refrigerated liquid...114 and 120) § 179.102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated liquid...

2014-10-01

378

49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.  

...2014-10-01 2014-10-01 false Carbon dioxide, refrigerated liquid. 179...114 and 120) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid...

2014-10-01

379

Miscibility of lubricants with refrigerants, Phase 1. Final report, 6 February 1992--15 October 1992  

SciTech Connect

Miscibility data have been obtained for a variety of non-CFC refrigerants and their potential lubricants. Ten different refrigerants and seven different lubricants were investigated. Experiments are being performed in two phases: Phase I, reported herein, focuses on performing screening tests for miscibility and Phase II consists of developing miscibility plots. The miscibility tests are being performed in a test facility consisting of a series of miniature test cells submerged in a constant temperature bath. The bath temperature can be precisely controlled over a temperature range of -50 C to 90C(-58 F to 194 F). The test cells are constructed to allow for complete visibility of lubricant-refrigerant mixtures under all test conditions.

Pate, M.B.; Zoz, S.C.; Berkenbosch, L.J. [Iowa State Univ. of Science and Technology, Ames, IA (United States). Dept. of Agricultural Engineering

1992-10-01

380

Measurements of the thermal conductivity of HFC-134a in the temperature range from 300 to 530 K at pressures up to 50 MPa  

SciTech Connect

Measurements of the thermal conductivity of HFC-134a made in a coaxial cylinder cell operating in steady state are reported. The measurements of the thermal conductivity of HFC-134a were performed along several quasi-isotherms between 300 and 530 K in the gas phase and the liquid phase. The pressure ranged from 0.1 to 50 MPa. Based on the experimental data, a black-ground equation is provided to calculate the thermal conductivity outside the critical region as a function of temperature and pressure. A careful analysis of the various sources of errors leads to an estimated uncertainty of {+-} 1.5%.

Le Neindre, B.; Garrabos, Y.

1999-09-01

381

Measurements of the thermal conductivity of HFC-125 in the temperature range from 300 to 515 K at pressures up to 53 MPa  

SciTech Connect

Measurements of the thermal conductivity of HFC-125 that have been made by a coaxial cylinder cell operating in steady state are reported. The measurements of the thermal conductivity of HFC-125 were performed along several quasi-isotherms between 300 and 515 K in the gas phase and the liquid phase. The pressure range covered varies from 0.1 to 53 MPa. Based on the measurement of more than 600 points, an empirical equation is provided to describe the thermal conductivity outside the critical region as a function of temperature and density. A careful analysis of the various sources of error leads to an estimated uncertainty of approximately {+-}1.5%.

Le Neindre, B. [Univ. Paris Nord, Villetaneuse (France). Institut Galilee] [Univ. Paris Nord, Villetaneuse (France). Institut Galilee; Garrabos, Y. [Univ. de Bordeaux 1, Pessac (France). Institut de Chimie de la Matiere Condensee] [Univ. de Bordeaux 1, Pessac (France). Institut de Chimie de la Matiere Condensee

1999-03-01

382

Mixture effects on horizontal convective boiling heat transfer  

Microsoft Academic Search

Mixture effects were studied in horizontal convective heat transfer for both nonazeotropic, R22\\/R114, and azeotropic, R12\\/R152a, mixtures. A test facility was designed, constructed, and operated to simulate evaporators in heat pump and refrigeration systems. More than 3000 local two-phase heat transfer coefficients were obtained under steady state condition for annular flow at a reduced pressure of 0.08. The ranges of

1988-01-01

383

Seven-effect absorption refrigeration  

DOEpatents

A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

DeVault, Robert C. (Knoxville, TN); Biermann, Wendell J. (Fayetteville, NY)

1989-01-01

384

Closed cycle liquid helium refrigerators  

NASA Astrophysics Data System (ADS)

We have developed closed cycle liquid helium refrigerators using a Joule Thomson circuit precooled by commercially available two staged Gifford Mac Mahon cryocoolers. The Joule Thomson counterflow heat exchangers are modular and have been thermo-hydraulically characterized. Fully automatic cool down and operation are achieved by two pneumatically driven by pass and expansion valves. Several apparatus have been built or are under assembly with cooling power ranging from 100 mW up to 5 Watt, for temperature ranging from 2.8 K up to 4.5 K. A trouble free operation with several warm up and cool down cycles has been proven over 7000 hours.

Claudet, G.; Lagnier, R.; Ravex, A.

385

Optimization of Industrial Refrigeration Systems  

E-print Network

of thermodynamics (energy balance) and the second law of thermodynamics (entropy balance) for the evaporative condenser an::! given by: W 21 + W 22 + (mOl hOI +01 31 h 31 ) I = (m02h02 + m 33 h 33 + m 43 h 43 ) (EQ17) W 21 +W22+Spr+(mOsOI +m 3I s 31... refrigeration designs the potential energy must be included in the evaluation when sizing the inter-: coolers and the accumulator). Spr represents the en tropy production within the control volume and Sii i~ the specific entropy of the corresponding mass...

Flack, P. J.; Sharp, M. K.; Case, M. E.; Gregory, R. W.; Case, P. L.

386

Seven-effect absorption refrigeration  

DOEpatents

A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit. 1 fig.

DeVault, R.C.; Biermann, W.J.

1989-05-09

387

A solar and electrical solid sorption refrigerator  

Microsoft Academic Search

A new solar and electrical refrigerator based on solid sorption phenomena was designed and tested. This refrigerator has very short (15 min) non-intermittent two adsorber heat recovery cycles and uses an active carbon fibre as a sorbent bed and ammonia as a working fluid. The system management involves only the actuation of valves of special type to change the direction

Leonard Leonardovich Vasiliev; Donatos Algirdo Mishkinis; Alexander Antonovich Antukh; Leonid Leonardovich Vasiliev

1999-01-01

388

Reusable tube piercing tool for refrigerant recovery  

SciTech Connect

A refrigerant tube piercing tool is described capable of being removably and sealingly mounted on a refrigerant tube of copper or the like in a sealed refrigerant system to enable the recovery of refrigerant from the sealed system without discharge into the atmosphere. The tool includes a pair of clamp members one of which includes a sealing member and passageway combined with a threaded, pointed piercing member that is manually threaded into engagement with the tube for forming a hole therein and a fitting having a Schrader valve incorporated therein to which a hose leading to a recovery tank can be connected to enable refrigerant to be transferred into the recovery tank for subsequent use. The tool is reusable and can be removed after the refrigerant has been transferred into the recovery tank in order that the leak or other problem with respect to the refrigerant system can be repaired at which time the hole formed in the tube is closed by soldering or the like with the refrigerant system then being recharged. 5 figs.

Price, L.D.; Scheiben, F.M.

1994-01-04

389

Natural Refrigerant, Geothermal Heating & Cooling Solutions  

E-print Network

Natural Refrigerant, Geothermal Heating & Cooling Solutions Lalit Chordia, PhD, Marc Portnoff 150.thargeo.com Thar Geothermal, LLC © 2013 All Rights Reserved CO2MFORT ADVANTAGE Nature's Talk Outline · Introduction to Thar Geothermal · Carbon Dioxide (R744) the Environmentally Exceptional Refrigerant · Thar

390

DESIGN ANALYSIS OF THE EINSTEIN REFRIGERATION CYCLE  

Microsoft Academic Search

After developing the theory of relativity, Albert Einstein spent several years working with Leo Szilard on absorption refrigeration cycles. In 1930, they obtained a U.S. patent for a unique single pressure absorption cycle. The single pressure eliminates the need for a solution pump. Their cycle has only recently been rediscovered. The cycle u tilizes butane as its refrigerant, ammonia as

Sam V. Shelton; Andrew Delano; Laura A. Schaefer

1998-01-01

391

A rocket-borne He-3 refrigerator  

NASA Technical Reports Server (NTRS)

A self-contained, recyclable He-3 refrigerator suitable for use in space has been developed. The refrigerator is compact, has no moving parts, and requires only electrical connections and thermal contact in order to operate from a 2 K cold stage. A charcoal adsorption pump is used to efficiently condense and cool the He-3. Sintered copper confines the He-3 to the evaporator in zero-gravity and, in fact, allows the refrigerator to operate upside-down in the laboratory. Mounted on a 2 K cold stage, the refrigerator provides 100 microwatts of cooling power at 346 mK, with a 7 hour hold time. On a 1.5 K cold stage, the lowest temperature achieved is 277 mK. The refrigerator has been vibration tested at 7.5 G amplitude from 30 to 400 Hz and 15 G amplitude from 400 to 2000 Hz.

Duband, L.; Alsop, D.; Lange, A.; Kittel, P.

1990-01-01

392

Dynamic simulation of a reverse Brayton refrigerator  

SciTech Connect

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.

Peng, N.; Xiong, L. Y.; Dong, B.; Liu, L. Q. [State Key Laboratory of Technologies in Space Cryogenic Propellants, Technical Institute of Physics and Chemistry, CAS, Beijing, 100190 (China); Lei, L. L.; Tang, J. C. [State Key Laboratory of Technologies in Space Cryogenic Propellants, Technical Institute of Physics and Chemistry, CAS, Beijing, 100190 China and Graduate University of Chinese Academy of Sciences, Beijing, 100190 (China)

2014-01-29

393

Dynamic simulation of a reverse Brayton refrigerator  

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

394

Compatibility of refrigerants and lubricants with elastomers  

SciTech Connect

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. 97% of the swell measurements have been made to date. The other 3% of the measurements are contingent on the availability of additional quantities of R-32. Swell behavior in the fluids have 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 hours and 24 hours for samples removed from the refrigerant test fluids and 24 hours after removal from the lubricants.

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

1992-10-01

395

Oil cooled, hermetic refrigerant compressor  

DOEpatents

A hermetic refrigerant compressor having an electric motor and compressor assembly in a hermetic shell is cooled by oil which is first cooled in an external cooler 18 and is then delivered through the shell to the top of the motor rotor 24 where most of it is flung radially outwardly within the confined space provided by the cap 50 which channels the flow of most of the oil around the top of the stator 26 and then out to a multiplicity of holes 52 to flow down to the sump and provide further cooling of the motor and compressor. Part of the oil descends internally of the motor to the annular chamber 58 to provide oil cooling of the lower part of the motor, with this oil exiting through vent hole 62 also to the sump. Suction gas with entrained oil and liquid refrigerant therein is delivered to an oil separator 68 from which the suction gas passes by a confined path in pipe 66 to the suction plenum 64 and the separated oil drops from the separator to the sump. By providing the oil cooling of the parts, the suction gas is not used for cooling purposes and accordingly increase in superheat is substantially avoided in the passage of the suction gas through the shell to the suction plenum 64.

English, William A. (Murrysville, PA); Young, Robert R. (Murrysville, PA)

1985-01-01

396

A PERFORMANCE EVALUATION OF A VARIABLE SPEED, MIXED REFRIGERANT HEAT PUMP. SUMMARY. EPA/600/SR-92/053  

EPA Science Inventory

The performance of an innovative heat pump, equipped with a distillation column to shift the composition of a zeotropic refrigerant mixture, was evaluated. The results of U.S. Department of Energy (DOE) rating tests and seasonal energy calcuations are reported with the main cycl...

397

Choice of Compressor Equipment for Compression-Throttling Cycles of Natural Gas Liquefaction Using a Mixed Refrigerant  

Microsoft Academic Search

We consider the prospects of improving compression-throttling cycles, the operating pressures of flows of a mixed refrigerant, the effect of the compressor efficiency on the specific energy inputs, the specifics of the hydrocarbon mixtures, and the economic aspects of liquefied natural gas production when compressors with a natural gas engine are used.

V. E. Gerasimov; R. V. Darbinyan; V. A. Peredel’skii

2005-01-01

398

Growth characteristics of Listeria monocytogenes as affected by a -native microflora in cooked ham under refrigerated and temperature abuse conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study examined the growth characteristics of L. monocytogenes as affected by a native microflora in cooked ham at refrigerated and abuse temperatures. A five-strain mixture of L. monocytogenes and a native microflora isolated from cooked meat were inoculated alone (monocultured) or co-inoculate...

399

First and second law analysis of a new power and refrigeration thermodynamic cycle using a solar heat source  

Microsoft Academic Search

The first and second laws of thermodynamics were used to analyze a novel thermodynamic cycle proposed by Goswami in 1995 that uses an ammonia–water binary mixture as the working fluid, while producing both power and refrigeration simultaneously. The thermodynamic performance of the cycle was optimized for maximum second law efficiency using a commercially available optimization program. A maximum second law

Afif Akel Hasan; D. Yogi Goswami; Sanjay Vijayaraghavan

2002-01-01

400

Refrigerator/freezer energy use: Measured values vs. simulation results  

SciTech Connect

The EPA Refrigerator Analysis (ERA) program was utilized in the engineering analysis performed to support the proposed refrigerator/freezer standards in the United States. In this paper the accuracy of the ERA program for predicting the energy consumption of domestic refrigerators, freezers, and refrigerator-freezers is studied by comparing the predicted energy consumption with the measured energy consumption.

Hakim, S.H.; Turiel, I. [Lawrence Berkeley National Lab., CA (United States). Energy and Environment Div.

1997-12-31

401

Design of a 126 Litre Refrigerator\\/Freezer Commercial Prototype  

Microsoft Academic Search

Designing a thermoelectric (TE) refrigerator\\/freezer to cost and performance targets set by refrigerator manufacturers is a difficult task which requires innovation and creative design, coupled with sound engineering practices. A 126 litre refrigerator, incorporating a 36 litre freezer compartment, was designed, built and performance tested to strict cost, efficiency and performance targets set by Matsushita Refrigeration Company (MARCO). The design

M. Davis; B. Manners; P. Clarke

402

Combined marine refrigerating and air conditioning system using thermal storage  

Microsoft Academic Search

A refrigerating and air conditioning system is described for a marine vessel which comprises: (a) a single compressor means to create a pressure differential in the refrigerant gas, and (b) a water cooled condenser to cause the pressurized refrigerant gas to liquify, and (c) a receiver to store liquidized refrigerant gas, and (d) a heat transfer means to transfer heat

Alston

1993-01-01

403

Dual-circuit, multiple-effect refrigeration system and method  

DOEpatents

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.

DeVault, Robert C. (Knoxville, TN)

1995-01-01

404

Valved pulse tube refrigerator development  

NASA Astrophysics Data System (ADS)

The pulse tube refrigerator is inherently reliable since it contains no moving parts at low temperature. However, the performance of a simple pulse tube is typically lower than that of other cryocoolers both in terms of COP and temperature differential per stage. Recent work indicates that the valved pulse tube, otherwise known as the orifice pulse tube, is able to reach much lower temperatures than the simple design, 31 K having been achieved in a two stage device. The addition of the valve and buffer volume subtly alters the heat pumping mechanism in the pulse tube. The valved pulse tube is described and the nature of the heat pumping machine explained. The current status of the device is reviewed.

Richardson, R. N.

405

Ferroelectric Stirling-Cycle Refrigerator  

NASA Technical Reports Server (NTRS)

A Stirling-cycle refrigerator has a three-pump configuration and pumping sequence, in which one pump serves as a compressor. one pump serves as an expander, and one pump serves as a displacer. The pumps are ferroelectrically actuated diaphragm pumps which are coordinated by synchronizing the ferroelectric-actuator voltages in such a way that the net effect of the displacer is to reduce the deleterious effect of dead space; that is, to circulate a greater fraction of the working fluid through the heat exchangers than would be possible by use of the compressor and expander alone. In addition. the displacer can be controlled separately to make the flow of working fluid in the heat exchangers turbulent (to increase the rate of transfer of heat at the cost of greater resistance to flow) or laminar (to decrease the resistance to flow at the cost of a lower heat-transfer rate).

Jalink, Antony, Jr. (Inventor); Hellbaum, Richard F. (Inventor); Rohrbach, Wayne W. (Inventor)

1999-01-01

406

Maximum profit performance of an absorption refrigerator  

SciTech Connect

The operation of an absorption refrigerator is viewed as a production process with exergy as its output. The relations between the optimal profit and COP (coefficient of performance), and the COP bound at the maximum profit of the refrigerator are derived based on a general heat transfer law. The results provide a theoretical basis for developing and utilizing a variety of absorption refrigerators. The focus of this paper is to search the compromise optimization between economics (profit) and the utilization factor (COP) for finite-time endoreversible thermodynamic cycles.

Chen, L.; Sun, F. [Naval Academy of Engineering, Wuhan (China)] [Naval Academy of Engineering, Wuhan (China); Wu, C. [Naval Academy, Annapolis, MD (United States). Mechanical Engineering Dept.] [Naval Academy, Annapolis, MD (United States). Mechanical Engineering Dept.

1996-12-01

407

Refrigerant charge management in a heat pump water heater  

DOEpatents

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.

Chen, Jie; Hampton, Justin W.

2014-06-24

408

Available energy analysis of new tandem double-capillary tube refrigeration system for refrigerator-freezers  

Microsoft Academic Search

A new tandem double-capillary tube refrigeration system for refrigerator-freezers is proposed. A capillary tube was added\\u000a between the two evaporators in the fresh and frozen food storage chests to raise the evaporation temperature of the refrigerating\\u000a chamber, and reduce the heat exchange temperature difference and the available energy loss. Peng-Robinson (P-R) equation of\\u000a state was adopted to calculate the thermodynamic

He Maogang; Song Xinzhou; Zhang Ying; Zhang Jiantao

2008-01-01

409

The performance analysis of a hydrocarbon refrigerant R-600a in a household refrigerator\\/freezer  

Microsoft Academic Search

The performance of a hydrocarbon refrigerant, R-600a, as an alternative for R-12 has been evaluated in a 215 ? household auto-defrost\\u000a refrigerator\\/freezer. A theoretical analysis was performed with NIST REFPROP, based on the ASHRAE refrigeration cycle and\\u000a a series of tests with R-600a was conducted according to the Korea Standard (KS C 9305). All the tests were performed in the

Man-Hoe Kim; Byung-Han Lim; Euy-Sung Chu

1998-01-01

410

A Solar-Gas\\/Electrical Solid Sorption Refrigerator  

Microsoft Academic Search

\\u000a Refrigeration technologies have been critical in the evolution of the production and distribution systems a long period of\\u000a time. The concept of solar-powered refrigeration cycles is known at least two decades and several refrigerators operating\\u000a on this principle are commercially available. Cohen and Cosar [1], have analyzed solar powered refrigeration. Guilleminot [2] demonstrated solar sorption refrigeration with cycle day\\/night to

L. L. Vasiliev; D. A. Mishkinis; A. A. Antukh

411

Energy and irreversibility analysis of a cascade refrigeration system for various refrigerant couples  

Microsoft Academic Search

This study deals with energy and irreversibility analysis of a cascade refrigeration system employing various refrigerant couples, namely R152a–R23, R290–R23, R507–R23, R234a–R23, R717–R23 and R404a–R23, using a computer code developed for this aim. It is assumed that the refrigeration load is 1kW, the refrigerated space temperature is ?40°C, and the environment temperature is 300K, while the degrees of condenser subcooling

A. Kilicarslan; M. Hosoz

2010-01-01

412

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

SciTech Connect

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 conditioning 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.

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

2012-01-01

413

Energy use of icemaking in domestic refrigerators  

SciTech Connect

This study was designed to develop and test a procedure to measure the electrical consumption of ice making in domestic refrigerators. The Department of Energy (DOE) test procedure was modified to include the energy used for icemaking in conventional refrigerators and those equipped with automatic icemakers. The procedure assumed that 500 grams of ice would be produced daily. Using the new test procedure and the existing DOE test (as a benchmark), four refrigerators equipped with automatic icemakers were tested for ice-making energy use. With the revised test, gross electricity consumption increased about 10% (100 kWh/yr) due to automatic icemaking but about 5% (55 kWh/yr) could be attributed to the special features of the automatic icemaker. The test also confirmed the feasibility of establishing procedures for measuring energy use of specific loads and other activities related to domestic refrigerators. Field testing and subsequent retesting revealed a 14% increase in energy use.

Meier, A. [Lawrence Berkeley National Lab., CA (United States). Energy and Environment Div.; Martinez, M.S. [ENVEST-SCE, Irwindale, CA (United States)

1996-02-01

414

Buy-back program recycles old refrigerators  

SciTech Connect

A refrigerator Buy-Back Program was initiated by the regional power utility, BC Hydron in 1990, with six pilot collection areas in British Columbia. As a result of the program's initial success, BC Hydro started a facility to dismantle old refrigerators, and the utility plans to expand its Refrigerator Buy-Back Program province-wide. BC Hydro's Refrigerator Buy-Back is the first utility-sponsored program of its kind in Canada. Similar appliance recycling efforts are underway in Milwaukee, Wisconsin and Hartford, Connecticut. Each of these programs was initiated to conserve electricity, but added benefits include waste reduction and removal of potential hazards such as freons and PCBs from the environment.

Musick, M.

1991-06-01

415

Enclosure for thermoelectric refrigerator and method  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

416

Intra-molecular refrigeration in enzymes  

E-print Network

We present a simple mechanism for intra-molecular refrigeration, where parts of a molecule are actively cooled below the environmental temperature. We discuss the potential role and applications of such a mechanism in biology, in particular in enzymatic reactions.

Hans J. Briegel; Sandu Popescu

2009-12-14

417

Refrigerant Compliance Updated: July 12, 2012  

E-print Network

........................................................................ 1 C. Recycling and Recovery Equipment of refrigerants into the environment. In accordance with Article 22 of the Indiana Administrative Code (326 IAC 22 - Stratospheric Ozone Protection) as well as Section 608 (National Recycling and Emission Reduction Program

Holland, Jeffrey

418

Refrigeration system having standing wave compressor  

DOEpatents

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.

Lucas, Timothy S. (Glen Allen, VA)

1992-01-01

419

Shuttle kit freezer refrigeration unit conceptual design  

NASA Technical Reports Server (NTRS)

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.

Copeland, R. J.

1975-01-01

420

Defrost Temperature Termination in Supermarket Refrigeration Systems  

SciTech Connect

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, 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.

Fricke, Brian A [ORNL; Sharma, Vishaldeep [ORNL

2011-11-01

421

21 CFR 1250.34 - Refrigeration equipment.  

Code of Federal Regulations, 2012 CFR

...REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment. Each...

2012-04-01

422

21 CFR 1250.34 - Refrigeration equipment.  

Code of Federal Regulations, 2011 CFR

...REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment. Each...

2011-04-01

423

21 CFR 1250.34 - Refrigeration equipment.  

Code of Federal Regulations, 2010 CFR

...REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment. Each...

2010-04-01

424

21 CFR 1250.34 - Refrigeration equipment.  

Code of Federal Regulations, 2013 CFR

...REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment. Each...

2013-04-01

425

21 CFR 1250.34 - Refrigeration equipment.  

...REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment. Each...

2014-04-01

426

Elastic Metal Alloy Refrigerants: Thermoelastic Cooling  

SciTech Connect

BEETIT Project: UMD is developing an energy-efficient cooling system that eliminates the need for synthetic refrigerants that harm the environment. More than 90% of the cooling and refrigeration systems in the U.S. today use vapor compression systems which rely on liquid to vapor phase transformation of synthetic refrigerants to absorb or release heat. Thermoelastic cooling systems, however, use a solid-state material—an elastic shape memory metal alloy—as a refrigerant and a solid to solid phase transformation to absorb or release heat. UMD is developing and testing shape memory alloys and a cooling device that alternately absorbs or creates heat in much the same way as a vapor compression system, but with significantly less energy and a smaller operational footprint.

None

2010-10-01

427

The miniature Joule-Thomson refrigerator  

NASA Astrophysics Data System (ADS)

Some models of planar cryogenic miniature refrigerator realizing simple Joule-Thomson cycle were worked out. The construction base is heat exchanger consisting of several thin metallic plates (stainless steel) connected by diffusion welding in vacuum. The channels are produced by means of modern technologies of photolythographie with electrochemical etching. The thermostatic temperature of 100 K was obtained by operating of refrigerator models on air and nitrogen gas, starting period duration is about 50 s.

Mikulin, Eugeny; Shevich, Jury; Danilenko, Tatiana; Solovov, Nikolay; Veselov, Valentin

428

Combined cold compressor/ejector helium refrigerator  

DOEpatents

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.

Brown, Donald P. (Southold, NY)

1985-01-01

429

Solid-Vapor Sorption Refrigeration Systems  

E-print Network

the problem from both directions. This proposal addresses only the second direction, the application of a new, highly efficient, refrigeration cycle using ammonia. Many industrial processes produce waste heat at various temperatures. This waste heat can... simultaneously approach the problem from both directions. This proposal addresses only the second direction, the application of a new, highly efficient, refrigeration cycle using ammonia. Many industrial processes produce waste heat at various temperatures...

Graebel, W.; Rockenfeller, U.; Kirol, L.

430

ARI delegation to Japan on Alternative Refrigerants  

SciTech Connect

Researchers from ARI member companies spoke at the International Conference on Alternative Refrigerants in Tokyo and visited several Japanese organizations for the purpose of exchanging information on alternative refrigerants. The specific purpose of the meetings was to review the methods being utilized to screen alternatives to CFCs and HCFCs: materials compatibility screening methods, lubricant testing techniques, as well as flammability studies. A list of papers presented at the conference is included.

Not Available

1993-02-01

431

Solar Refrigerator/Freezers For Vaccines  

NASA Technical Reports Server (NTRS)

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.

Ratajczak, Anthony F.

1988-01-01

432

The Oak Ridge Refrigerant Management Program  

SciTech Connect

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 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 Program.

Kevil, T.H.

1995-03-01

433

Vaccine refrigeration technologies and power sources  

SciTech Connect

Adequate refrigeration of vaccines is an essential component of the worldwide child immunization effort sponsored cooperatively by such development assistance agencies as the World Health Organization, the United Nations Children's Fund, and the US Agency for International Development (AID), and by developing countries. Unfortunately, the areas in most urgent need of effective immunization programs are often far from reliable refrigerated storage facilities or energy services. Selection of an appropriate energy supply and/or refrigeration technology has been seen as a limiting factor in effective immunization programs. In response to this problem, this document has been prepared to assist in the selection of reliable and affordable refrigeration systems. It provides information on refrigeration technologies and energy sources currently employed in the vaccine cold chain and discusses possible responses to a variety of energy-related problems, including intermittent or unreliable electric service, and unreliable supply, unavailability, or poor quality of fuels for refrigerators in health centers not served by the electric power grid. 18 refs., 5 figs.

Rovero, C.; Waddle, D. (Oak Ridge Associated Universities, Inc., TN (USA); Oak Ridge National Lab., TN (USA))

1989-10-01

434

Energy Efficient Operation of Ammonia Refrigeration Systems  

SciTech Connect

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, employ 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.

Mohammed, Abdul Qayyum [University of Dayton, Ohio] [University of Dayton, Ohio; Wenning, Thomas J [ORNL] [ORNL; Sever, Franc [University of Dayton, Ohio] [University of Dayton, Ohio; Kissock, Professor Kelly [University of Dayton, Ohio] [University of Dayton, Ohio

2013-01-01

435

Near azeotropic mixture substitute for dichlorodifluoromethane  

NASA Technical Reports Server (NTRS)

The present invention comprises a refrigerant mixture having two halocarbon components. The first component is present in a mole fraction of about 0.7 to less than 1.0 while the second component is present in a mole fraction of more than 0.0 to about 0.3. The first component is CH.sub.2 FCF.sub.3. The second component can be CHClFCF.sub.3, CH.sub.3 CClF.sub.2, a mixture of CHClFCF.sub.3 and CH.sub.3 CClF.sub.2, a mixture of CHF.sub.2 CH.sub.3 and CHClFCF.sub.3, a mixture of CHF.sub.2 CH.sub.3 and CH.sub.3 CClF.sub.2, or a mixture of CHClFCF.sub.3, CH.sub.3 CClF.sub.2 and CHF.sub.2 CH.sub.3. The preferred embodiment of this invention comprises about 0.7 to less than 1.0 mole fraction CH.sub.2 FCF.sub.3, and more than 0.0 to about 0.3 mole fraction of a mixture of CHClFCF.sub.3 and CH.sub.3 CClF.sub.2. The most preferred embodiment of this invention comprises about 0.7 to less than 1.0 mole fraction CH.sub.2 FCF.sub.3 and more than 0.0 to about 0.3 mole fraction CH.sub.3 CClF.sub.2. The resulting refrigerant has a vapor pressure close to-that of CF.sub.2 Cl.sub.2, a nearly constant vapor pressure with evaporation, and is substantially less damaging to the Earth's ozone layer than CF.sub.2 Cl.sub.2.

Jones, Jack A. (Inventor)

1996-01-01

436

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 ...

437

Efficient electrochemical refrigeration power plant using natural gas with ?100% CO2 capture  

NASA Astrophysics Data System (ADS)

We propose an efficient Natural Gas (NG) based Solid Oxide Fuel Cell (SOFC) power plant equipped with ?100% CO2 capture. The power plant uses a unique refrigeration based process to capture and liquefy CO2 from the SOFC exhaust. The capture of CO2 is carried out via condensation and purification using two rectifying columns operating at different pressures. The uncondensed gas mixture, comprising of relatively high purity unconverted fuel, is recycled to the SOFC and found to boost the power generation of the SOFC by 22%, when compared to a stand alone SOFC. If Liquefied Natural Gas (LNG) is available at the plant gate, then the refrigeration available from its evaporation is used for CO2 Capture and Liquefaction (CO2CL). If NG is utilized, then a Mixed Refrigerant (MR) vapor compression cycle is utilized for CO2CL. Alternatively, the necessary refrigeration can be supplied by evaporating the captured liquid CO2 at a lower pressure, which is then compressed to supercritical pressures for pipeline transportation. From rigorous simulations, the power generation efficiency of the proposed processes is found to be 70-76% based on lower heating value (LHV). The benefit of the proposed processes is evident when the efficiency of 73% for a conventional SOFC-Gas turbine power plant without CO2 capture is compared with an equivalent efficiency of 71.2% for the proposed process with CO2CL.

Al-musleh, Easa I.; Mallapragada, Dharik S.; Agrawal, Rakesh

2015-01-01

438

Boiling heat transfer of refrigerant R-113 in a small-diameter, horizontal tube  

SciTech Connect

Results of a study of boiling heat transfer from refrigerant R-113 in a small-diameter (2.92-mm) tube are reported. Local heat transfer coefficients over a range of heat fluxes, mass fluxes, and equilibrium mass qualities were measured. The measured coefficients were used to evaluate eight different heat transfer correlations, some of which have been developed specifically for refrigerants. High heat fluxes and low flow rates are inherent in small channels, and this combination results in high boiling numbers. The high boiling number of the collected data shows that the nucleation mechanism was dominant. As a result, the two-phase correlations that predicted this dominance also predicted the data best if they also properly modeled the physical parameters. The correlations of Lazarek and Black and of Shah, as modified in this study, predicted the data very well. It is also shown that a simple form, suggested by Stephan and Abdelsalam for nucleate boiling, correlates the data equally well. This study is part of a research program in multiphase flow and heat transfer, with the overall objective of developing validated design correlations and predictive methods that will facilitate the design and optimization of compact heat exchangers for use with environmentally acceptable alternatives for chlorofluorocarbon (CFC) refrigerants and refrigerant mixtures.

Wambsganss, M.W.; Jendrzejczyk, J.A.; Tran, T.N. [Argonne National Lab., IL (United States); France, D.M. [Illinois Univ., Chicago, IL (United States). Dept. of Mechanical Engineering

1992-01-01

439

Visualization and measurement of refrigerant flow in compression-type refrigerator by neutron radiography  

NASA Astrophysics Data System (ADS)

The refrigerant two-phase flows in a capillary tube and a distributor used in a compression-type refrigerator were visualized by real-time neutron radiography. The thermal neutron radiography system of JRR-3M at the Japan Atomic Energy Research Institute was used. In the visualization experiments of the two-phase flow in the capillary tube of 2 mm I.D., a cooled CCD camera was used, and the axial one-dimensional distributions of void fraction were measured. For the distributor, a high sensitivity video camera with a silicone intensified target tube was used. From the visualized images, the refrigerant behaviors in the distributor were clearly shown, and the liquid fraction in each tube was measured. As a result, it was shown that the refrigerant behaviors in the distributor effected the distributing performance of the refrigerant flow.

Asano, H.; Takenaka, N.; Fujii, T.; Shibata, Y.; Ebisu, T.; Matsubayashi, M.

1999-11-01

440

Barocaloric effect and the pressure induced solid state refrigerator  

SciTech Connect

The current refrigerators are based on the heating and cooling of fluids under external pressure variation. The great inconvenience of this refrigeration technology is the damage caused to the environment by the refrigerant fluids. In this paper, we discuss the magnetic barocaloric effect, i.e., the heating or cooling of magnetic materials under pressure variation and its application in the construction of refrigerators using solid magnetic compounds as refrigerant materials and pressure as the external agent. The discussion presented in this paper points out that such a pressure induced solid state refrigerator can be very interesting because it is not harmful to the environment and can exhibit a good performance.

Oliveira, N. A. de [Instituto de Fisica Armando Dias Tavares Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier 524, Rio de Janeiro, 20550-013, RJ (Brazil)

2011-03-01

441

Influence of locust bean gum\\/?-carrageenan mixtures on whipping and mechanical properties and stability of dairy creams  

Microsoft Academic Search

The influence of locust bean gum (LBG)–?-carrageenan mixtures on whipping properties and rheological properties of whipped dairy cream was analysed as a function of the gum concentration. Whipping properties (time and overrun) and mechanical properties (creep compliance and extrusion tests) were studied on whipped cream immediately after whipping and after 24h refrigeration (5°C). The stabiliser mixtures in the studied concentration

M. M Camacho; N Mart??nez-Navarrete; A Chiralt

1998-01-01

442

A Superfluid Pulse Tube Refrigerator Without Moving Parts for Sub-Kelvin Cooling  

NASA Technical Reports Server (NTRS)

A report describes a pulse tube refrigerator that uses a mixture of He-3 and superfluid He-4 to cool to temperatures below 300 mK, while rejecting heat at temperatures up to 1.7 K. The refrigerator is driven by a novel thermodynamically reversible pump that is capable of pumping the He-3 He-4 mixture without the need for moving parts. The refrigerator consists of a reversible thermal magnetic pump module, two warm heat exchangers, a recuperative heat exchanger, two cold heat exchangers, two pulse tubes, and an orifice. It is two superfluid pulse tubes that run 180 out of phase. All components of this machine except the reversible thermal pump have been demonstrated at least as proof-of-concept physical models in previous superfluid Stirling cycle machines. The pump consists of two canisters packed with pieces of gadolinium gallium garnet (GGG). The canisters are connected by a superleak (a porous piece of VYCOR glass). A superconducting magnetic coil surrounds each of the canisters.

Miller, Franklin K.

2012-01-01

443

The thermal conductivity of binary mixtures of liquid R22 with R142b and R152a at low temperatures  

NASA Astrophysics Data System (ADS)

The paper presents the thermal conductivity of mixtures of liquid refrigerants, The group of systems studied consists of two binary mixtures of R22/R142b and R22/R152a. The measurements have been carried out in the temperature range 160 300 K for pressures From 0.2 to 8.0 MPa in a transient coaxial-cylinder instrument. The uncertainty of the thermal conductivity data is estimated to be ±2%. The experimental method and apparatus were validated by using the measurements of refrigerant R22. The results presented have been used to develop a correlation for the description of the thermal conductivity of refrigerants.

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

1996-05-01

444

Cold chain: solar refrigerator field tested.  

PubMed

The Health Ministries of Colombia and Peru, in collaboration with the Expanded Program on Immunization (EPI)/Pan American Health Organization (PAHO) and the Centers for Disease Control (CDC), have begun field testing a solar-powered vaccine refrigerator. The aim of the fields trials is to determine whether solar refrigerators can maintain the temperatures required for vaccine storage (+4-8 degrees Celsius) and produce ice at a rate of 2 kg/24 hours under different environmental conditions. these refrigerators would be particularly useful in areas that lack a consistent supply of good quality fuel or where the electrical supply is intermittent or nonexistent. Full appraisal of this technology will require 2 years of field testing; Colombia and Peru expect to complete testing in 1985. To date, 5 models have passed CDC-developed specifications, all of which are manufactured in the US. PAHO/WHO recommends that health ministries should consider the following guidelines in considering the purchase of a particular system: the initial purchase should be for a limited quantity (about 5) of refrigerators to permit field testing; solar panels should meet specific criteria; consideration should be given only to those models that have passed qualification tests; each unit should be fully equipped with monitoring devices and spare parts; and a trained refrigerator technician should be available to repair the equipment. PMID:12314506

1983-04-01

445

Refrigerator DSM programs: Status and prospects  

SciTech Connect

The energy use of new refrigerators in the US has decreased by nearly 50 percent since 1980, driven by federal standards and utility demand-side management (DSM) programs. With today`s new refrigerators so much more efficient than earlier products, are refrigerators still an attractive target for demand-side management efforts? An E Source analysis of US utility programs reveals the following: (1) The retirement of older, inefficient refrigerators from homes with two or more units is generally a cost-effective DSM approach, with savings of about 1,000 kWh per year for every spare unit that is eliminated from use and not replaced with a new model. (2) Hundreds of new models exceed federal efficiency standards by at least 10 percent, using 50 to 300 kWh per year less than the standards allow. Modest incentives for these machines can still be cost-effective for some utilities, although many rebate programs have been dropped. (3) More utilities are targeting rebates and other incentives ``upstream`` to retailers or manufacturers as a means of increasing the leverage of DSM investments. (4) Multi-utility efforts, such as the establishment of uniform performance targets by several utilities, can be more effective than individual utility programs in moving the market for higher efficiency refrigerators, and are getting increasing attention.

George, K.L.; Shepard, M.

1994-12-31

446

Potential Refrigerants for Power Electronics Cooling  

SciTech Connect

In the past, automotive refrigerants have conventionally been used solely for the purpose of air conditioning. However, with the development of hybrid-electric vehicles and the incorporation of power electronics (PEs) into the automobile, automotive refrigerants are taking on a new role. Unfortunately, PEs have lifetimes and functionalities that are highly dependent on temperature and as a result thermal control plays an important role in the performance of PEs. Typically, PEs are placed in the engine compartment where the internal combustion engine (ICE) already produces substantial heat. Along with the ICE heat, the additional thermal energy produced by PEs themselves forces designers to use different cooling methods to prevent overheating. Generally, heat sinks and separate cooling loops are used to maintain the temperature. Disturbingly, the thermal control system can consume one third of the total volume and may weigh more than the PEs [1]. Hence, other avenues have been sought to cool PEs, including submerging PEs in automobile refrigerants to take advantage of two-phase cooling. The objective of this report is to explore the different automotive refrigerants presently available that could be used for PE cooling. Evaluation of the refrigerants will be done by comparing environmental effects and some thermo-physical properties important to two-phase cooling, specifically measuring the dielectric strengths of potential candidates. Results of this report will be used to assess the different candidates with good potential for future use in PE cooling.

Starke, M.R.

2005-10-24

447

Comparative analysis of CO 2 -based transcritical Rankine cycle and HFC245fa-based subcritical organic Rankine cycle using low-temperature geothermal source  

Microsoft Academic Search

A detailed thermodynamic and techno-economic comparison is presented for a CO2-based transcritical Rankine cycle and a subcritical organic Rankine cycle (ORC) using HFC245fa (1,1,1,3,3-pentafluoro-propane)\\u000a as the working fluid driven by the low-temperature geothermal source, in order to determine the configuration that presents\\u000a the maximum net power output with a minimum investment. The evaluations of both Rankine cycles have been performed

Tao Guo; HuaiXin Wang; ShengJun Zhang

2010-01-01

448

CONTROL OF HYDROCARBON EMISSIONS FROM GASOLINE LOADING BY REFRIGERATION SYSTEMS  

EPA Science Inventory

The report gives results of a study of the capabilities of refrigeration systems, operated at three temperatures, to control volatile organic compound (VOC) emissions from truck loading at bulk gasoline terminals. Achievable VOC emission rates were calculated for refrigeration sy...

449

46 CFR 98.25-35 - Refrigerated systems.  

Code of Federal Regulations, 2011 CFR

...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-35 Refrigerated systems. (a) Where refrigerated systems are installed to maintain...

2011-10-01

450

46 CFR 98.25-35 - Refrigerated systems.  

...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-35 Refrigerated systems. (a) Where refrigerated systems are installed to maintain...

2014-10-01

451

46 CFR 98.25-35 - Refrigerated systems.  

Code of Federal Regulations, 2013 CFR

...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-35 Refrigerated systems. (a) Where refrigerated systems are installed to maintain...

2013-10-01

452

46 CFR 98.25-35 - Refrigerated systems.  

Code of Federal Regulations, 2010 CFR

...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-35 Refrigerated systems. (a) Where refrigerated systems are installed to maintain...

2010-10-01

453

46 CFR 98.25-35 - Refrigerated systems.  

Code of Federal Regulations, 2012 CFR

...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-35 Refrigerated systems. (a) Where refrigerated systems are installed to maintain...

2012-10-01

454

Fully portable, highly flexible dilution refrigerator systems for neutron scattering  

E-print Network

775 Fully portable, highly flexible dilution refrigerator systems for neutron scattering P. A systems developed specifically for neutron scattering environ- ments. The refrigerators are completely relatively recently however, the lowest temperatures available in almost all neutron scattering laboratories

Boyer, Edmond

455

TEMPERATURE PREDICTION IN DOMESTIC REFRIGERATOR: DETERMINIST AND STOCHASTIC APPROACHES  

E-print Network

TEMPERATURE PREDICTION IN DOMESTIC REFRIGERATOR: DETERMINIST AND STOCHASTIC APPROACHES O. LAGUERRE temperature and thermostat setting, on air and load temperatures in non ventilated domestic refrigerator inside the cavity. The normal distribution of ambient and thermostat temperatures was developed to fit

Paris-Sud XI, Université de

456

Optimal Design Refrigeration System for a Mucilage Glue Fiber Factory  

E-print Network

In a mucilage glue fiber factory, the design of the refrigeration system takes into account the characteristics of mucilage glue fiber production and fully uses the refrigeration compressor heat to economize energy and reduce the production cost...

Tan, C.; Liu, J.; Tang, F.; Liu, Y.

2006-01-01

457

Optimal performance of endoreversible quantum refrigerators  

E-print Network

The derivation of general performance benchmarks is important in the design of highly optimized heat engines and refrigerators. To obtain them, one may model phenomenologically the leading sources of irreversibility ending up with results which are model-independent, but limited in scope. Alternatively, one can take a simple physical system realizing a thermodynamic cycle and assess its optimal operation from a complete microscopic description. We follow this approach in order to derive the coefficient of performance at maximum cooling rate for \\textit{any} endoreversible quantum refrigerator. At striking variance with the \\textit{universality} of the optimal efficiency of heat engines, we find that the cooling performance at maximum power is crucially determined by the details of the specific system-bath interaction mechanism. A closed analytical benchmark is found for endoreversible refrigerators weakly coupled to unstructured bosonic heat baths: an ubiquitous case study in quantum thermodynamics.

Luis A. Correa; José P. Palao; Gerardo Adesso; Daniel Alonso

2014-08-03

458

Optimal performance of endoreversible quantum refrigerators  

NASA Astrophysics Data System (ADS)

The derivation of general performance benchmarks is important in the design of highly optimized heat engines and refrigerators. To obtain them, one may model phenomenologically the leading sources of irreversibility ending up with results that are model independent, but limited in scope. Alternatively, one can take a simple physical system realizing a thermodynamic cycle and assess its optimal operation from a complete microscopic description. We follow this approach in order to derive the coefficient of performance at maximum cooling rate for any endoreversible quantum refrigerator. At striking variance with the universality of the optimal efficiency of heat engines, we find that the cooling performance at maximum power is crucially determined by the details of the specific system-bath interaction mechanism. A closed analytical benchmark is found for endoreversible refrigerators weakly coupled to unstructured bosonic heat baths: an ubiquitous case study in quantum thermodynamics.

Correa, Luis A.; Palao, José P.; Adesso, Gerardo; Alonso, Daniel

2014-12-01

459

Load leveling on industrial refrigeration systems  

NASA Astrophysics Data System (ADS)

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.

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

1982-01-01

460

An adiabatic demagnetization refrigerator for SIRTF  

SciTech Connect

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). The authors have built one such refrigerator which employs a ferric ammonium alum salt pill suspended by nylon threads in a 3 Tesla solenoid. The resonant modes of this suspension are above 100 Hz. The heat leak to the salt pill is <0.5 ..mu..W. The system has a hold time at 0.1 /sup 0/K of >12 hours. The cold stage temperature is regulated with a feedback loop that controls the magnetic field. A second, similar refrigerator is being built as a SIRTF prototype to fly on a balloon-borne telescope. It will employ a ferromagnetic shield. The possibility of using high T/sub c/ leads to the superconducting magnet and a solenoid-actuated heat switch are also discussed.

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

1989-02-01

461

Toxicity Data to Determine Refrigerant Concentration Limits  

SciTech Connect

This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

Calm, James M.

2000-09-30

462

Analysis of a combined Rankine–vapour–compression refrigeration cycle  

Microsoft Academic Search

This paper describes a theoretical analysis of a heat-powered refrigeration cycle, a combined Rankine–vapour–compression refrigeration cycle. This refrigeration cycle combines an Organic Rankine Cycle and a vapour–compression cycle. The cycle can be powered by low grade thermal energy as low as 60°C and can produce cooling temperature as low as ?10°C. In the analysis, two combined Rankine–vapour–compression refrigeration cycles were

Satha Aphornratana; Thanarath Sriveerakul

2010-01-01

463

Simulation results of single refrigerants for use in a dual-circuit refrigerator/freezer  

SciTech Connect

Dual-circuit RFs have been shown to have a theoretical advantage over single-evaporator RFs if the compressor efficiencies of the separate loops are equivalent to the compressor efficiency of the combined system. Single refrigerants were analyzed to determine the optimum pure refrigerant in each of the two separate freezer and fresh food loops. R-152a and R-142b were determined to be the optimum single refrigerants in the dual-circuit system. With the assumptions made, theoretical energy savings of up to 23% of compressor power are possible.

Bare, J.C. (Environmental Protection Agency, Research Triangle Park, NC (United States))

1992-02-01

464

Boiling Heat Transfer to Halogenated Hydrocarbon Refrigerants  

NASA Astrophysics Data System (ADS)

The current state of knowledge on heat transfer to boiling refrigerants (halogenated hydrocarbons) in a pool and flowing inside a horizontal tube is reviewed with an emphasis on information relevant to the design of refrigerant evaporators, and some recommendations are made for future research. The review covers two-phase flow pattern, heat transfer characteristics, correlation of heat transfer coefficient, influence of oil, heat transfer augmentation, boiling from tube-bundle, influence of return bend, burnout heat flux, film boiling, dryout and post-dryout heat transfer.

Yoshida, Suguru; Fujita, Yasunobu

465

Helium refrigeration considerations for cryomodule design  

SciTech Connect

Many of the present day accelerators are based on superconducting radio frequency (SRF) cavities, packaged in cryo-modules (CM), which depend on helium refrigeration at sub-atmospheric pressures, nominally 2 K. These specialized helium refrigeration systems are quite cost intensive to produce and operate. Particularly as there is typically no work extraction below the 4.5-K supply, it is important that the exergy loss between this temperature level and the CM load temperature(s) be minimized by the process configuration choices. This paper will present, compare and discuss several possible helium distribution process arrangements to support the CM loads.

Ganni, V.; Knudsen, P. [Thomas Jefferson National Accelerator Facility (JLab), Newport News, VA 23606 (United States)

2014-01-29

466

Literature survey on thermophysical properties of refrigerants  

SciTech Connect

A bibliographic compilation is given on thermophysical properties of the environmentally acceptable hydrofluorocarbon blends R404A, R407C, and R410A. These refrigerant blends are still under investigation and meant to replace the transitional hydrochlorofluorocarbon R22 and the azeotrope R502. In a second part reliable formulations to calculate thermophysical-property surfaces of some selected well investigated fluids used in refrigeration are recommended. The fluids water, air, carbon dioxide, ammonia, R134a, R123, and R152a are subjects of that part.

Krauss, R.; Stephan, K. [Univ. Stuttgart (Germany). Inst. fuer Technische Thermodynamik and Thermische Verfahrenstechnik

1998-11-01

467

Literature Survey on Thermophysical Properties of Refrigerants  

NASA Astrophysics Data System (ADS)

A bibliographic compilation is given on thermophysical properties of the environmentally acceptable hydrofluorocarbon blends R404A, R407C, and R410A. These refrigerant blends are still under investigation and meant to replace the transitional hydrochlorofluorocarbon R22 and the azeotrope R502. In a second part reliable formulations to calculate thermophysical-property surfaces of some selected well investigated fluids used in refrigeration are recommended. The fluids water, air, carbon dioxide, ammonia, R134a, R123, and R152a are subjects of that part.

Krauss, R.; Stephan, K.

1998-11-01

468

Eddy current heating in magnetic refrigerators  

NASA Technical Reports Server (NTRS)

Eddy current heating can be a significant source of parasitic heating in low temperature magnetic refrigerators. To study this problem a technique to approximate the heating due to eddy currents has been developed. A formula is presented for estimating the heating within a variety of shapes commonly found in magnetic refrigerators. These shapes include circular, square, and rectangular rods; cylindrical and split cylindrical shells; wire loops; and 'coil foil. One set of components evaluated are different types of thermal radiation shields. This comparison shows that a simple split shield is almost as effective (only 23 percent more heating) as using a shield, with the same axial thermal conductivity, made of 'coil foil'.

Kittel, Peter

1990-01-01

469

Entanglement enhances cooling in microscopic quantum refrigerators.  

PubMed

Small self-contained quantum thermal machines function without external source of work or control but using only incoherent interactions with thermal baths. Here we investigate the role of entanglement in a small self-contained quantum refrigerator. We first show that entanglement is detrimental as far as efficiency is concerned-fridges operating at efficiencies close to the Carnot limit do not feature any entanglement. Moving away from the Carnot regime, we show that entanglement can enhance cooling and energy transport. Hence, a truly quantum refrigerator can outperform a classical one. Furthermore, the amount of entanglement alone quantifies the enhancement in cooling. PMID:24730798

Brunner, Nicolas; Huber, Marcus; Linden, Noah; Popescu, Sandu; Silva, Ralph; Skrzypczyk, Paul

2014-03-01

470

Design of Industrial Process Refrigeration Systems  

E-print Network

DESIGN OF INDUSTRIAL PROCESS REfRIGERATION SYSTEMS W.O. WITHERELL AOVENTg Technolog1st Un10n Carb1de Corporat1on South Charleston, West V1rg~n1a ABSTRACT ~hen considering electric driven refrigeration compressors, proper integration... with the process may result in reduced power consl.lllltion. However, the total uti I itV situation must be cons idered when eva Iuat i ng the cOl1llressor dr i ver . Conyers ion frOOl steam drivers to electric drivers may be IOClre econOOlical when cons ider i...

Witherell, W. D.

471

An analytical screening of alternatives for R-502 in low-temperature refrigerating applications  

NASA Astrophysics Data System (ADS)

R-502 is used as the working fluid of low-temperature refrigerating systems with evaporating temperatures as low as -40 F (-40 C). It was selected as the refrigerant of choice for these applications because it is both nonflammable and nontoxic and has an acceptable compressor discharge temperature when used in a high-efficiency vapor-compression system. Replacement fluids are going to be needed for use in place of R-502, however, because of the provisions of the Montreal Protocol. R-502 is an azeotropic blend of R-22 and R-115, and R-115 is a chlorofluorocarbon (CFC). The provisions of the Montreal Protocol currently require a total phase-out of the production of all fully halogenated CFCs, including R-115, by the year 2000. Consequently, replacement fluids will be needed for new and existing equipment. This study was initiated to identify other possible fluids that can be used either in new or retrofit applications for low-temperature refrigerant. It includes an evaluation of predicted cycle efficiency, system capacity, pressure ratio, fluid flammability, and compressor discharge temperature. Eight different chemical compounds are considered for use as pure refrigerants as well as components in binary and ternary mixtures: R-134a, R-134, R-125, R-143a, R-152a, R-32, R-124, and R-22. An exhaustive study of the composition of blends was performed to determine the mass fractions of each component in the mixtures that are most promising on the basis of efficiency, flammability, low discharge temperature, and acceptable capacity and pressure ratio. Several blends are identified for further laboratory and analytical evaluation.

Fischer, S. K.

472

Evaporative system for water and beverage refrigeration in hot countries  

E-print Network

Evaporative system for water and beverage refrigeration in hot countries A Saleh1 and MA Al-Nimr2 1 Abstract: The present study proposes an evaporative refrigerating system used to keep water or other are found to be consistent with the available literature data. Keywords: evaporative refrigeration, heat

473

1st TECCS meeting, 26th April 2007 Adsorption Refrigeration  

E-print Network

bed, both to reduce the cycle time / size and to use regenerative cycles. 2.Doing it with zero cost cycles for: Heat pumps Refrigerators Air conditioning Driven by heat from: Fossil fuels Bio fuels Waste refrigerant into a solid as the basis of a refrigeration cycle. It all started with Faraday in 1821... #12;1st

Davies, Christopher

474

DEVELOPMENT OF A HIGH EFFICIENCY, AUTOMATIC DEFROSTING REFRIGERATOR-FREEZER  

E-print Network

#12;DEVELOPMENT OF A HIGH EFFICIENCY, AUTOMATIC DEFROSTING REFRIGERATOR-FREEZER Richard F. Topping-efficient refrigerator- freezer prototype involving the Department of Energy's Oak Ridge National Laboratory, Arthur D refrigerator-freezers. The resulting 16 cubic foot prototype uses significantly less energy than the most

Oak Ridge National Laboratory

475

Control method for mixed refrigerant based natural gas liquefier  

DOEpatents

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.

Kountz, Kenneth J. (Palatine, IL); Bishop, Patrick M. (Chicago, IL)

2003-01-01

476

Method and apparatus for de-superheating refrigerant  

DOEpatents

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.

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

1997-11-25

477

Carbon Dioxide and Ionic Liquid Refrigerants: Compact, Efficient Air Conditioning with Ionic Liquid-Based Refrigerants  

SciTech Connect

BEETIT Project: Notre Dame is developing an air-conditioning system with a new ionic liquid and CO2 as the working fluid. Synthetic refrigerants used in air conditioning and refrigeration systems are potent GHGs and can trap 1,000 times more heat in the atmosphere than CO2 alone—making CO2 an attractive alternative for synthetic refrigerants in cooling systems. However, operating cooling systems with pure CO2 requires prohibitively high pressures and expensive hardware. Notre Dame is creating a new fluid made of CO2 and ionic liquid that enables the use of CO2 at low pressures and requires minimal changes to existing hardware and production lines. This new fluid also produces no harmful emissions and can improve the efficiency of air conditioning systems— enabling new use of CO2 as a refrigerant in cooling systems.

None

2010-10-01

478

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

DOEpatents

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.

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

2006-02-07

479

Visualization and measurement of refrigerant flow in compression-type refrigerator by neutron radiography  

Microsoft Academic Search

The refrigerant two-phase flows in a capillary tube and a distributor used in a compression-type refrigerator were visualized by real-time neutron radiography. The thermal neutron radiography system of JRR-3M at the Japan Atomic Energy Research Institute was used. In the visualization experiments of the two-phase flow in the capillary tube of 2mm I.D., a cooled CCD camera was used, and

H. Asano; N. Takenaka; T. Fujii; Y. Shibata; T. Ebisu; M. Matsubayashi

1999-01-01

480

Simulation Results of Single Refrigerants for Use in Dual-Circuit Refrigerator\\/Freezer  

Microsoft Academic Search

Dual-circuit RFs have been shown to have a theoretical advantage over single-evaporator RFs if the compressor efficiencies of the separate loops are equivalent to the compressor efficiency of the combined system. Single refrigerants were analyzed to determine the optimum pure refrigerant in each of the two separate freezer and fresh food loops. R-152a and R-142b were determined to be the

Jane C. Bare

1992-01-01

481

Air Conditioning and Refrigeration Supplementary Units.  

ERIC Educational Resources Information Center

This document contains supplemental materials for special needs high school students intended to facilitate their mainstreaming in regular air conditioning and refrigeration courses. Teacher's materials precede the materials for students and include general notes for the instructor, additional suggestions, two references, a questionnaire on the…

Winston, Del; And Others

482

The Absorption Refrigerator as a Thermal Transformer  

ERIC Educational Resources Information Center

The absorption refrigerator can be considered a thermal transformer, that is, a device that is analogous to the electric transformer. The analogy is based on the correspondence between the extensive quantities, entropy and electric charge and the intensive variables, temperature and electric potential. (Contains 1 footnote and 6 figures.)

Herrmann, F.

2009-01-01

483

Air Conditioning and Refrigeration. Book One.  

ERIC Educational Resources Information Center

Designed to provide students with the basic skills for an occupation in air conditioning and refrigeration, this curriculum guide includes seven major areas, each consisting of one or more units of instruction. These areas and their respective units are titled as follows: Orientation (history and development, and job opportunities), Safety…

Wantiez, Gary W.

484

Uninterrupted power supply for autonomous small refrigerators  

Microsoft Academic Search

The objective of this paper is to describe salient features of a small refrigerator powered by a field of photovoltaic panels backed up by a petrol-start, kerosene-run portable generator set. Such units find applications in medical shops, veterinary applications and storage of vaccines in primary health centers. The modular arrangement allows use of certain components as a part of an

Thomachan A. Kattakayam; K. Srinivasan

1998-01-01

485

Residential Refrigerator Recycling Ninth Year Retention Study  

E-print Network

Residential Refrigerator Recycling Ninth Year Retention Study Study ID Nos. 546B, 563 Prepared RECYCLING PROGRAMS Study ID Nos. 546B and 563 Prepared for Southern California Edison Rosemead, California Prepared by KEMA Inc. Madison, Wisconsin July 22, 2004 Copyright © 2004 by KEMA Inc. All rights reserved

486

Air Conditioning and Refrigeration. Book Two.  

ERIC Educational Resources Information Center

This curriculum guide (book II), along with book I, is designed to provide students with the basic skills for an occupation in air conditioning and refrigeration. Six major areas are included, each consisting of one or more units of instruction. These areas and their respective units are titled as follows: Electricity (fundamentals of electricity,…

Wantiez, Gary W.

487

Refrigeration in a world without CFCs  

SciTech Connect

In an era of heightened awareness of energy efficiency and the associated environmental impacts, many industries, worldwide, are exploring ``environmentally friendly`` technologies that provide equivalent or improved performance while reducing or eliminating harmful side effects. The refrigeration and air conditioning industry, due to its reliance on CFCs and HCFCs has invested in research in alternatives to the industry standard vapor compression machines. One alternative technology with great promise is chemical absorption. Absorption chillers offer comparable refrigeration output with reduced SO{sub 2}, CO{sub 2}, and NO{sub x} emissions. Additionally, absorption chillers do not use CFCs or HCFCs, refrigerants that contribute to ozone depletion and global warming. The purpose of this paper is to provide an introduction for those new to absorption technology as well as a discussion of selected high efficiency cycles and environmental impacts for those familiar with absorption. The introduction will include a brief history of absorption and a description of the basic refrigeration cycle, while the advanced sections will discuss triple-effect technology and a life-cycle or ``systems`` approach to evaluating global warming impacts.

Garland, R.W. [U.S. Dept. of Energy, Washington D.C. (United States); Adcock, P.W. [Oak Ridge National Lab., TN (United States)

1996-09-01

488

Metrics for Air Conditioning & Refrigeration, Heating, Ventilating.  

ERIC Educational Resources Information Center

Designed to meet the job-related metric measurement needs of the air conditioning and refrigeration, heating and ventilating student, this instructional package is one of three for the construction occupations cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already…

Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

489

Solar aqua-ammonia absorption refrigerator simulation  

Microsoft Academic Search

Thermodynamic analysis of an Ammonia-water absorption refrigeration cycle performance, using solar energy in the generator, is simulated by means of a PC program. The economic feasibility of the system for ice production is studied in two southern locations of Spain. For the solar energy collection unit, a Compound Parabolic Collector (CPC) is considered. The optimal value of the Coefficient of

E. Elegido; J. M. De Juana; M. A. Herrero

1991-01-01

490

Application of refrigeration system in electronics cooling  

Microsoft Academic Search

An experimental investigation of the transient response of the vapor compression refrigeration (VCR) system to rapid change in evaporator (simulated electronics) heat load is presented. In this study, the VCR system is designed and constructed specifically for applications to cool high heat flux electronics and high-end computers. Temperature and pressure data were measured at pre-selected locations to study the behavior

A. G. Agwu Nnanna

2006-01-01

491

Variable refrigerant flow systems: A review  

Microsoft Academic Search

This review study presents a detailed overview of the configurations of the outdoor and indoor units of a multi-split variable refrigerant flow (VRF) system, and its operations, applications, marketing and cost. Besides, a detailed review about the experimental and numerical studies asso