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1

Vapor–Liquid Equilibria of CFC Alternative Refrigerant Mixtures: Trifluoromethane (HFC23)+Difluoromethane (HFC32), Trifluoromethane (HFC23)+Pentafluoroethane (HFC125), and Pentafluoroethane (HFC125)+1,1-Difluoroethane (HFC152a)  

Microsoft Academic Search

Isothermal vapor–liquid equilibria for three binary mixtures of CFC alternative refrigerants were determined in an equilibrium apparatus in which both phases were continuously recirculated. The pressures and vapor and liquid compositions were measured for the binary systems trifluoromethane (HFC-23)+difluoromethane (HFC-32) and trifluoromethane (HFC-23)+pentafluoroethane (HFC-125) at 283.15 and 293.15 K and pentafluoroethane (HFC-125)+1,1-difluoroethane (HFC-152a) at 293.15 K. The experimental data were

J. S. Lim; J.-Y. Park; B.-G. Lee

2000-01-01

2

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...

3

Performance evaluation of two azeotropic refrigerant mixtures of HFC134a with R-290 (propane) and R-600a (isobutane)  

Microsoft Academic Search

The reduction in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) production and the scheduled phase-out of these ozone-depleting refrigerants require the development and determination of environmentally safe refrigerants for use in heat pumps, water chillers, air conditioners, and refrigerators. This paper presents a performance evaluation of a generic heat pump with two azeotropic refrigerant mixtures of HFC-134a (1,1,1,2-tetrachloroethane) with R-290 (propane) and

M. S. Kim; W. J. Mulroy; D. A. Didion

1994-01-01

4

An Assessment of Thermodynamic Models for HFC Refrigerant Mixtures Through the Critical-Point Calculation  

NASA Astrophysics Data System (ADS)

An assessment of thermodynamic models for HFC refrigerant mixtures based on Helmholtz energy equations of state was made through critical-point calculations for ternary and quaternary mixtures. The calculations were performed using critical-point criteria expressed in terms of the Helmholtz free energy. For three ternary mixtures: difluoromethane (R-32) + pentafluoroethane (R-125) + 1,1,1,2-tetrafluoroethane (R-134a), R-125 + R-134a + 1,1,1-trifluoroethane (R-143a), and carbon dioxide (CO2) + R-32 + R-134a, and one quaternary mixture, R-32 + R-125 + R-134a + R-143a, calculated critical points were compared with experimental values, and the capability of the mixture models for representing the critical behavior was discussed.

Akasaka, Ryo

2008-08-01

5

Performance evaluation of two azeotropic refrigerant mixtures of HFC-134a with R-290 (propane) and R-600a (isobutane)  

SciTech Connect

The reduction in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) production and the scheduled phase-out of these ozone-depleting refrigerants require the development and determination of environmentally safe refrigerants for use in heat pumps, water chillers, air conditioners, and refrigerators. This paper presents a performance evaluation of a generic heat pump with two azeotropic refrigerant mixtures of HFC-134a (1,1,1,2-tetrachloroethane) with R-290 (propane) and R-600a (isobutane); R-290/134a (45/55 by mass percentage) and R-134a/600a (80/20 by mass percentage). The performance characteristics of the azeotropes were compared with pure CFC-12, HFC-134a, HCFC-22, and R-290 at the high temperature cooling and heating conditions including those using liquid-line/suction-line heat exchange. The coefficient of performance of R-290/134a is lower than that of HCFC-22 and R-290, and R-134a/600a shows higher coefficient of performance than CFC-12 and HFC-134a. The capacity for R-290/134a is higher than that for HCFC-22 and R-290, and R-134a/600a exhibits higher system capacity than CFC-12 and HFC-134a. Experimental results show that the discharge temperatures of the studied azeotropic mixtures are lower than those of the pure refrigerants, CFC-12 and HCFC-22.

Kim, M.S.; Mulroy, W.J.; Didion, D.A. (National Inst. of Standards and Technology, Gaithersburg, MD (United States). Building and Fire Research Lab.)

1994-06-01

6

Improved energy efficiency for CFC domestic refrigerators retrofitted with ozone-friendly HFC134a\\/HC refrigerant mixture  

Microsoft Academic Search

Conversion of CFC12 systems to eco-friendly ones will be a major thrust area for refrigeration sector in the near future. As and when an existing CFC (chlorofluorocarbon) system has to be recharged it is advisable to retrofit the system with an eco-friendly energy efficient refrigerant. Presently two potential substitutes, namely, HFC134a and HC blends are available as drop in substitutes

S. Joseph Sekhar; D. Mohan Lal; S. Renganarayanan

2004-01-01

7

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

8

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...

9

Evaluation for Practical Application of HFC Refrigerants  

NASA Astrophysics Data System (ADS)

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

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

10

Vapor+Liquid Equilibrium Measurements and Correlation of the Binary Refrigerant Mixtures Difluoromethane (HFC32)+1,1,1,2,3,3-Hexafluoropropane (HFC236ea) and Pentafluoroethane (HFC125)+1,1,1,2,3,3-Hexafluoropropane (HFC236ea) at 288.6, 303.2, and 318.2 K  

Microsoft Academic Search

Isothermal vapor–liquid equilibria (VLE) for the binary systems of difluoromethane (HFC-32)+1,1,1,2,3,3-hexafluoropropane (HFC-236ea) and pentafluoroethane (HFC-125)+1,1,1,2,3,3-hexafluoropropane (HFC-236ea) were measured at 288.6, 303.2, and 318.2 K using an apparatus in which the vapor phase was recirculated through the liquid. The phase composition at equilibrium was measured by gas chromatography, based on calibration using gravimetrically prepared mixtures. Both systems show a slight deviation

S. Bobbo; L. Fedele; M. Scattolini; R. Camporese

2000-01-01

11

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

12

Performance of a Small-sized Refrigeration Comperssor Using HFC-134a  

NASA Astrophysics Data System (ADS)

When CFC-12 is replaced by HFC-134a in small-sized refrigeration compressors for domestic refrigerators, the coefficient of performance (COP) of rotary compressors decreases. On the other hand,the COP of reciprocating compressors is almost the same as that of CFC-12. The main causes of rotary compressor performance decrease are higher viscosity of HFC-134a/oil mixture,and greater re-expansion loss of gas in clearance volume. The performance is improved by optimizing the oil viscosity through directly measuring viscosity of HFC-134a/oil mixture inside the compressor chamber with a viscosity sensor. Difference of oil type has small influence on the COP.

Kohsokabe, Hirokatsu; Endoh, Kazuhiro; Kunugi, Yoshifumi; Iwata, Hiroshi; Hata, Hiroaki; Fujiwara, Mitsuru

13

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...

14

Gaseous thermal conductivity of difluoromethane (HFC-32), pentafluoroethane (HFC-125), and their mixtures  

NASA Astrophysics Data System (ADS)

The gaseous thermal conductivity of dilluoromethane (HFC-32). pentalluoroethane (HFC-125). and their binary mixtures was measured with a transient hot-wire apparatus in the temperature ranges 283 333 K at pressures up to saturation. The uncertainty of the data is estimated to be within I %. The thermal conductivity as a function of composition of the mixtures at constant pressure and temperature is found to have a small maximum near 0.3 0.4 mole fraction of HFC-32. The gaseous thermal-conductivity data obtained for pure HFC-32 and HFC-125 were correlated with temperature and density together with the liquid thermal-conductivity data from the literature, based on the excess thermal-conductivity concept. The composition dependence of the thermal conductivity at a constant temperature is represented with the aid of the Wassiljewa equation.

Tanaka, Y.; Matsuo, S.; Taya, S.

1995-01-01

15

HFC-134A and HCFC-22 supermarket refrigeration demonstration and laboratory testing. Phase I. Final report  

SciTech Connect

Aspen Systems and a team of nineteen agencies and industry participants conducted a series of tests to determine the performance of HFC-134a, HCFC-22, and CFC-502 for supermarket application. This effort constitutes the first phase of a larger project aimed at carrying out both laboratory and demonstration tests of the most viable HFC refrigerants and the refrigerants they replace. The results of the Phase I effort are presented in the present report. The second phase of the project has also been completed. It centered on testing all viable HFC replacement refrigerants for CFC-502. These were HFC-507, HFC-404A, and HFC-407A. The latter results are published in the Phase II report for this project. As part of Phase I, a refrigeration rack utilizing a horizontal open drive screw compressor was constructed in our laboratory. This refrigeration rack is a duplicate of one we have installed in a supermarket in Clifton Park, NY.

NONE

1996-04-01

16

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

17

Gaseous thermal conductivity of difluoromethane (HFC32), pentafluoroethane (HFC125), and their mixtures  

Microsoft Academic Search

The gaseous thermal conductivity of dilluoromethane (HFC-32). pentalluoroethane (HFC-125). and their binary mixtures was measured with a transient hot-wire apparatus in the temperature ranges 283–333 K at pressures up to saturation. The uncertainty of the data is estimated to be within I %. The thermal conductivity as a function of composition of the mixtures at constant pressure and temperature is

Y. Tanaka; S. Matsuo; S. Taya

1995-01-01

18

An Experimental Investigaton of the Effect of Oil on Convective Heat Trasfer and Pressure Drop of a HFC-32/HRC-125 Mixture  

E-print Network

The heat transfer coefficients and pressure drops of HCFC-22 and a 50% mass mixture of HFC-32/HFC-125 were experimentally measured under flow boiling conditions in a smooth tube. The refrigerants were flowed through an 8 mm diameter smooth tube...

McJimsey, Bert Ashford

19

Solubility, viscosity and density of refrigerant/lubricant mixtures  

SciTech Connect

This report presents results for 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, CFC-12/ISO 100 naphthenic mineral oil, HFC-134a/ISO 22 pentaerythritol ester mixed acid, HFC-134a/ISO 32 pentaerythritol ester mixed acid [number sign]1, HFC-134a/ISO 68 pentaerythritol ester mixed acid, HFC-134a/ISO 100 pentaerythritol ester mixed acid, HFC-134a/ISO 32 pentaerythritol ester mixed acid [number sign]2, HCFC-123/ISO 32 naphthenic mineral oil, HCFC-123/ISO 100 naphthenic mineral oil, HCFC-123/150 SUS alkylbenzene, HCFC-123/300 SUS alkylbenzene. These data have been reduced to engineering form and are presented in the form of a Daniel Chart. Equations are given along with statistical measures of goodness of fit.

Henderson, D.R.

1993-04-01

20

Viscosity of gaseous mixtures of HFC125 (pentafluoroethane) + HFC134a (1,1,1,2-tetrafluoroethane) under pressure  

Microsoft Academic Search

This paper reports experimental results for the viscosity of gaseous mixtures of HFC-125 (pentafluoroethane) + HFC-134a (1,1,1,2-tetrafluoroethane) under pressure. The measurements were carried out with an oscillating-disk viscometer of the Maxwell type at temperatures from 298.15 to 423.15K. The viscosity was measured for three mixtures (mole fraction of HFC-125 is 0.7510, 0.5001 or 0.2508). The viscosity at normal pressure was

Chiaki Yokoyama; Tomomichi Nishino; Mitsuo Takahashi

2000-01-01

21

Simulation of vapor-compression refrigeration cycles using HFC134a and CFC12  

SciTech Connect

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 developed, system performance with HFC134a and CFC12 are examined. A comparison of the performance of HFC134a and CFC12 is presented using COP (and compressor power) as a criterion for the same cooling load. Results indicate that the COP for HFC134a is slightly (about 3%) lower than that for a CFC12 system. This means that the power requirement for a HFC134a system is slightly higher than that for CFC12 system for an identical cooling requirement. A comparison of these two systems from a thermodynamic point of view is also presented using exergy loss as a performance evaluation criterion. These results indicate that the HFC134a system is only slightly inferior to the CFC 12 systems due to a higher (about 3%) exergy loss with HFC134a.

Chen, Q. [Combustion Dynamics Ltd., Halifax, Nova Scotia (Canada)] [Combustion Dynamics Ltd., Halifax, Nova Scotia (Canada); Prasad, R.C. [Univ. of New Brunswick, Saint John, New Brunswick (Canada). Dept. of Engineering] [Univ. of New Brunswick, Saint John, New Brunswick (Canada). Dept. of Engineering

1999-05-01

22

New concepts for refrigerant leak detection and mixture measurement  

SciTech Connect

Since the discovery that chlorofluorocarbons (CFCs) destroy the ozone layer, the need to reduce the release of these refrigerants into the environment has become critical. A total ban of ozone-depleting CFCs is expected within a few years, and hydrofluorocarbons (HFCs) and fluorocarbons (FCs) and their mixtures are expected to be used during a transition period. Several HFC and FC refrigerants are currently being considered as CFC substitutes. The electronic refrigerant leak detectors currently being considered as CFC substitutes. The electronic refrigerant leak detectors currently on the market were developed to detect CFCs and are not as sensitive to HFCs. Although incremental improvement can be made to these devices to detect HFCs, they often lead to increased false signals. Also, there is no simple device available to measure the composition of a refrigerant mixture. The authors present two new concepts to aid in the development of two portable instruments that can be used for HFC leak detection and for quantitative measurement of refrigerant mixture compositions. The development of simple, easy-to-use portable leak detectors and refrigerant mixture meters is essential to the wide use of alternative refrigerants in industry.

Chen, F.C.; Allman, S.L.; Chen, C.H.

1993-12-31

23

Solubility of HFC-134a refrigerant in glycol-type compounds: Effects of glycol structure. [1,1,1,2-tetrafluoroethane  

SciTech Connect

Environmental concerns have dictated the replacement of CFC-12 refrigerant with HFC-134a in air-conditioning (A/C) systems. Since polyglycols are synthetic compounds compatible with HFC-134a and considered as lubricants for the A/C compressor, interactions of HFC-134a with glycol-type compounds and thermodynamic properties of the solutions are important in designing an A/C system. In this work, the solubility of HFC-134a in four glycol-type compounds was measured at [minus]5 to 80 C and 90 to 960 kPa. HFC-134a had the greatest solubility in tetraethylene glycol dimethyl ether. HFC-134a was less soluble in hexylene glycol and tetraethylene glycol and least soluble in triethylene glycol. Mixtures of HFC-134a with TRIG or TGDE showed phase separation. Solubility data were used to calculate the activity coefficient of HFC-134a in glycol solutions. An equation of the form, ln[gamma][sub r] = (1 [minus] x[sub r])[A + Bx[sub r

Tseregounis, S.I.; Riley, M.J. (General Motors Research and Development Center, Warren, MI (United States). Fuels and Lubricants Dept.)

1994-04-01

24

Helmholtz Energy Equations of State for HFC and Natural Refrigerants and Their Applications to Calculations of Thermodynamic Properties  

NASA Astrophysics Data System (ADS)

This paper overviews Helmholtz energy equations of state for pure HFC and natural refrigerants. The equations of state consist of the ideal-gas part and the residual part. The ideal-gas part can be calculated from the ideal-gas isobaric heat capacity according to the ideal-gas law, and the residual part is determined empirically by fitting to experimental thermodynamic property data. Polynomial and exponential terms are used to represent the residual part. Some equations have more complex terms for accurate descriptions of critical behavior. Mixture models for applications of the pure-fluid equations of state to refrigerant mixtures are summarized. Until now, two mixture models have been developed for HFC refrigerant mixtures. This paper also discusses calculation methods for the pvT relation, vapor-liquid equilibrium, and critical point using Helmholtz energy equations of state. Few literature discusses the methods in detail, although such information is very precious to make a computer program for calculating thermodynamic properties.

Akasaka, Ryo

25

Performance investigation of capillary tubes for machine tool coolers retrofitted with HFC-407C refrigerant  

NASA Astrophysics Data System (ADS)

The machine tool coolers are the best managers of coolant temperature in avoiding the deviation of spindle centerline for machine tools. However, the machine coolers are facing the compressed schedule to phase out the HCFC (hydro-chloro-floro-carbon) refrigerant and little attention has been paid to comparative study on sizing capillary tube for retrofitted HFC (hydro-floro-carbon) refrigerant. In this paper, the adiabatic flow in capillary tube is analyzed and modeled for retrofitting of HFC-407C refrigerant in a machine tool cooler system. A computer code including determining the length of sub-cooled flow region and the two phase region of capillary tube is developed. Comparative study of HCFC-22 and HFC-407C in a capillary tube is derived and conducted to simplify the traditional trial-and-error method of predicting the length of capillary tubes. Besides, experimental investigation is carried out by field tests to verify the simulation model and cooling performance of the machine tool cooler system. The results from the experiments reveal that the numerical model provides an effective approach to determine the performance data of capillary tube specific for retrofitting a HFC-407C machine tool cooler. The developed machine tool cooler system is not only directly compatible with new HFC-407C refrigerant, but can also perform a cost-effective temperature control specific for industrial machines.

Wang, Fujen; Chang, Tongbou; Chiang, Weiming; Lee, Haochung

2012-09-01

26

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...

27

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

28

Releases of refrigerant gases (CFC-12, HCFC-22 and HFC-134a) to the atmosphere  

NASA Astrophysics Data System (ADS)

Two of the gases, CFC-12 (dichlorodifluoromethane, CF 2Cl 2) and HCFC-22 (chlorodifluoromethane, CHClF 2) have long histories of emission from refrigeration and other uses. Production and sales records show the expected fall in the amounts of CFC-12 used in refrigeration after the Montreal Protocol came into effect but this does not seem to have been accompanied by significant substitution by HCFC-22, demand for which appears governed by organic growth. HFC-134a (1,1,1,2-tetrafluoroethane, CH 2FCF 3) is a relative newcomer that has partially substituted for CFC-12. After developing a single data set for the global use of each substance in refrigeration, foam blowing and aerosol propulsion, and other promptly emissive uses, annual releases of the compounds were estimated by applying emission functions derived from surveying both the producers of the chemicals and the principal industrial users. For CFC-12 and HFC-134a, atmospheric concentrations calculated from the emissions estimated here are in good agreement with observations, verifying that the emission functions adequately describe the relationship between the quantities in use, the atmospheric lifetimes of 100 and 14.6 years, respectively, and the extent of release into the atmosphere. The agreement between observation and calculation is poorer for HCFC-22, if its atmospheric lifetime is 12 years, but becomes much closer with a lifetime of 10 years. An 80% reduction in CFC requirement has been substituted only to the extent of 25% by HFC-134a. This is consistent with improved technology to curtail leakage and so enable lower system charges that, in turn, translate into less demand. For the same reason, the refrigeration emission function for HFC-134a over the period 1990-2000 was not significantly different from that of CFC-12. The lower absolute rate of leakage and lower absolute charge sizes combining to maintain a similar relative rate of loss.

McCulloch, Archie; Midgley, Pauline M.; Ashford, Paul

29

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

30

Comparison of HFC-134a and the ternary blend, Suva MP39, as replacements for the refrigerant, CGC-12  

NASA Astrophysics Data System (ADS)

The refrigerant gas CFC-12 has been widely used in Royal Australian Navy (RAN) equipment. With the Montreal protocol phase-out of this and other ozone depleting substances, alternative refrigerant gases must be identified. These replacements would ideally have the same efficiency as CFC-12, cause no health and safety risks and allow changeover to proceed with minimal costs. This paper reviews the attributes of two refrigerant gases, HFC-134a and Suva MP39, which are being considered by the RAN.

Fletcher, Lyn E.

1993-09-01

31

Solubility, viscosity and density of refrigerant/lubricant mixtures. Quarterly technical progress report, 1 January--31 March 1993  

SciTech Connect

This report presents results for 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, CFC-12/ISO 100 naphthenic mineral oil, HFC-134a/ISO 22 pentaerythritol ester mixed acid, HFC-134a/ISO 32 pentaerythritol ester mixed acid {number_sign}1, HFC-134a/ISO 68 pentaerythritol ester mixed acid, HFC-134a/ISO 100 pentaerythritol ester mixed acid, HFC-134a/ISO 32 pentaerythritol ester mixed acid {number_sign}2, HCFC-123/ISO 32 naphthenic mineral oil, HCFC-123/ISO 100 naphthenic mineral oil, HCFC-123/150 SUS alkylbenzene, HCFC-123/300 SUS alkylbenzene. These data have been reduced to engineering form and are presented in the form of a Daniel Chart. Equations are given along with statistical measures of goodness of fit.

Henderson, D.R.

1993-04-01

32

Performance characteristics of HFC-134a and HFC-410A refrigeration system using a short-tube orifice as an expansion device  

NASA Astrophysics Data System (ADS)

In the present article, the effect of heat source temperature, heat sink temperature, short-tube orifice diameter and short-tube orifice length on the performance characteristics of HFC-140A and HFC-134a refrigeration system using a short-tube orifice as expansion device, i.e., mass flow rate, cooling capacity, compressor pressure ratio, power consumption, and second law efficiency are experimentally studied. The short-tube orifices diameters ranging from 0.849 to 1.085 mm with length ranging from 10 to 20 mm are used in this examination. The test run are done at heat source temperature ranging between 16.5 and 18.5°C, and heat sink temperature ranging between 30 and 35°C. The results show that the tendency of second law efficiency is increased as the short-tube orifice diameter and heat source temperature are enhanced, but it is decreased by increasing the short-tube orifice length and heat sink temperature. Under the similar conditions, the mass flow rate, cooling capacity, and compressor power consumption obtained from HFC-410A are higher than those obtained from HFC-134a.

Nilpueng, Kitti; Supavarasuwat, Chietta; Wongwises, Somchai

2011-10-01

33

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

34

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 ...

35

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 ...

36

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

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

37

IMPROVING THE ENERGY EFFECTIVENESS OF DOMESTIC REFRIGERATORS BY THE APPLICATION OF REFRIGERANT MIXTURES*  

E-print Network

#12;IMPROVING THE ENERGY EFFECTIVENESS OF DOMESTIC REFRIGERATORS BY THE APPLICATION OF REFRIGERANT.S. and foreign literature on the use of a mixture of refrigerants rather than a single one in a refrigeration-evaporator refrigerator typical of domestic refrigerators showed an energy savings of 12 percent. By acceptance

Oak Ridge National Laboratory

38

Phase equilibria of chlorofluorocarbon alternative refrigerant mixtures  

SciTech Connect

Isothermal vapor-liquid equilibrium data were determined for binary systems of difluoromethane/1,1,1,2-tetrafluoroethane (HFC-32/HFC-134a), difluoromethane/pentafluoroethane (HFC-32/HFC-125), difluoromethane/1,1,1-trifluoroethane (HFC-32/HFC-143A), and difluoromethane/1,1-difluoroethane (HFC-32/HFC-152a). The vapor and liquid compositions and pressures were measured in a circulation-type apparatus at 303.15 K and 323.15 K. The experimental data were compared with literature results and correlated with the Canahan-Starling-De Santis equation of state within the uncertainty of {+-}1.0%.

Lee, B.G.; Park, J.Y.; Lim, J.S.; Cho, S.Y.; Park, K.Y. [Korea Inst. of Science and Technology, Seoul (Korea, Republic of)] [Korea Inst. of Science and Technology, Seoul (Korea, Republic of)

1999-03-01

39

Modeling and design study using HFC-236ea as an alternative refrigerant in a centrifugal compressor. Final report, January 1994-September 1995  

SciTech Connect

The Environmental Protection Agency (EPA) in cooperation with the Navy has been seeking a CFC-114 drop-in placement. One alternative HFC refrigerant which appears to satisfy all physical and chemical characteristics for the Navy fleet was found to be HFC-236ea refrigerant. The project represents a part of the investigation directed to evaluate this CFC-114 alternative refrigerant as a possible drop-in replacement in Navy chillers. The objective of the study was to conduct a thorough literature review regarding centrifugal compressors and the, on the basis of the information gathered, build an accurate but simple compressor model utilizing the available compressor experimental data. Further, the developed compressor model would be used to suggest eventual design adjustments to enhance compressor performance with the alternative HFC-236ea refrigerant.

Popovic, P.; Shapiro, H.N.

1997-04-01

40

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

Microsoft Academic Search

The Peng-Robinson equation of state with the van der Waals mixing rules was used to correlate vapor–liquid equilibrium (VLE)\\u000a data for HFC\\/HC, HFC\\/HFC, and HC\\/HC binary mixtures. The interaction parameter k\\u000a \\u000a ij\\u000a was obtained for every binary mixture. It was assumed that k\\u000a \\u000a ij\\u000a has contributions from the two components, and each component has its own constant contribution factor k

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

2008-01-01

41

Application of nanoparticles in domestic refrigerators  

Microsoft Academic Search

The reliability and performance of a domestic refrigerator with nanoparticles in the working fluid was investigated experimentally. Mineral oil with TiO2 nanoparticles mixtures were used as the lubricant instead of Polyol-ester (POE) oil in the 1,1,1,2-tetrafluoroethane (HFC134a) refrigerator. The compatibility of nonmetallic materials in the system with the HFC134a and mineral oil–nanoparticles mixtures was studied before the refrigerator performance tests.

Sheng-shan Bi; Lin Shi; Li-li Zhang

2008-01-01

42

Condensation of Downward-Flowing Zeotropic Mixture HCFC-123/HFC-134a on a Staggered Bundle of Horizontal Low-Finned Tubes  

NASA Astrophysics Data System (ADS)

Expenmentswere conducted to obtain row-by-row heat transfer data during condensation of downward-flowing zeotropic refrigerant mixture HCFC-123/HFC-134 a on a staggered bundle of horizontal low-finned tubes. The vapor temperature and the HFC-134a m ass fraction at the tube bundle inlet were maintained at about 50°C and 14% respectively. The refrigerant mass velocity ranged from 9 to 33 kg/m2s, and the condensation temperature difference from 2 to 12K. Four kinds of low-finned tubes with different fin geometry were tested. The highest heat transfer coefficient was obtained with a tube which showed the highest performance for HCFC-123. However, the effect of fin geometry was much smaller for the mixture than for HCFC-123. The heat transfer coefficient and the vapor-phase mass transfer coefficient decreased significantly with decreasing mass velocity. On the other hand, the mass transfer coefficient increased with condensation temperature difference. This was due to the effect of suction associated with condensation. On the basis of the analogy between heat and mass transfer, a dimensionless correlation of the mass transfer coefficient was developed for each tube.

Honda, Hiroshi; Takamatsu, Hiroshi; Takata, Nobuo

43

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...

44

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

45

Relative permittivity and resistivity of liquid HFC refrigerants under high pressure  

SciTech Connect

The static relative permittivity (dielectric constant) and the resistivity of HFC-236ea (CF{sub 3}-CHF-CHF{sub 2}) and HFC-245fa (CF{sub 3}-CH{sub 2}-CHF{sub 2}) in the liquid phase were studied at temperatures from 293 to 343 K and pressures from 0.1 to 50 MPa. The relative permittivity was measured by a concentric-cylinder-type capacitance cell with an LCR meter with an uncertainty of less than 0.1%. The resistivity was measured by a high resistance meter using plane-parallel platinum electrodes installed in a borosilicate glass syringe. It was found that the relative permittivities and the resistivities of liquid HFC-236ea and HFC-245fa at 303 K and 0.101325 MPa are about 5.13 and 6.54 and 1.5 {times} 10{sup 10} and 0.2 {times} 10{sup 10} {Omega} {center_dot} cm, respectively. The relative permittivity and the resistivity increase monotonically with increasing pressure and decreasing temperature.

Tanaka, Y.; Matsuo, S.; Sotani, T.; Kondo, T.; Matsuo, T. [Kobe Univ. (Japan). Dept. of Chemical Science and Engineering] [Kobe Univ. (Japan). Dept. of Chemical Science and Engineering

1999-01-01

46

Elastohydrodynamic Lubrication with Polyolester Lubricants and HFC Refrigerants, Final Report, Volume 1  

SciTech Connect

The objective of this study was to investigate the film formation properties of refrigeration lubricants using the ultrathin film elastohydrodynamic (EHD) interferometry technique and to study the effects of refrigerants on film formation. Film thickness measurements were conducted as a function of lubricant viscosity, speed, temperature, and refrigerant concentration. Based on the EHD film thickness data, effective pressure-viscosity coefficients were calculated for the test fluids at different temperatures and the effects of refrigerants on pressure-viscosity properties were investigated.

Gunsel, Selda; Pozebanchuk, Michael

1999-04-01

47

Accelerated screening methods for determining chemical and thermal stability of refrigerant-lubricant mixtures part II: Experimental comparisons and verification of methods. Quarterly technical progress report, October 1, 1993--March 31, 1994  

SciTech Connect

The research reported herein continued to concentrate on in situ conductivity measurements for development into an accelerated screening method for determining the chemical and thermal stabilities of refrigerant/lubricant mixtures. The work reported herein was performed in two phases. In the first phase, sealed tubes were prepared with steel catalysts and mixtures of CFC-12, HCFC-22, HFC-134a, and HFC-32/HFC-134a (zeotrope 30:70) refrigerants with oils as described in ANSI/ASHRAE Method 97-1989. In the second phase of work, modified sealed tubes, with and without steel catalysts present, were used to perform in situ conductivity measurements on mixtures of CFC-12 refrigerant with oils. The isothermal in situ conductivity measurements were compared with conventional tests, e.g., color measurements, gas chromatography, and trace metals to evaluate the capabilities of in situ conductivity for determining the chemical and thermal stabilities of refrigerant/lubricant mixtures. Other sets of tests were performed using ramped temperature conditions from 175{degrees}C (347{degrees}F) to 205{degrees}C (401{degrees}F) to evaluate the capabilities of in situ conductivity for detecting the onset of rapid degradation in CFC-12, HCFC-22 and HFC-134a refrigerant mixtures with naphthenic oil aged with and without steel catalysts present.

Kauffman, R. [Dayton Univ., OH (United States). Research Inst.

1994-07-01

48

Emissions of the refrigerants HFC-134a, HCFC-22, and CFC-12 from road traffic: results from a tunnel study (Gubrist Tunnel, Switzerland).  

PubMed

This study presents the quantification of the emissions of the refrigerants CFC-12 (CCl2F2), HCFC-22 (CHClF2), and HFC-134a (CF3CH2F) from road traffic in Switzerland. These gases are used as refrigerants in car air conditioning systems (A/C-systems) and in cool aggregates for refrigeration transport. All three substances act as greenhouse gases, and CFC-12 and HCFC-22 are in addition stratospheric ozone depleting chemicals. The measurements have been performed in a highway tunnel in the area of Zürich and cover a large number of individual vehicles, which are thought to be representative of a typical European car fleet. The average emission rates per vehicle were found to be 1.0 +/- 0.2 mg h(-1) for CFC-12, 0.6 +/- 0.4 mg h(-1) for HCFC-22, and 6.2 +/- 0.8 mg h(-1) for HFC-134a. These emission factors have been measured for driving vehicles and represent an average emission rate for all types of vehicles regardless of whether they are equipped with an A/C-unit or not. For an average vehicle equipped with an A/C-unit, these results translate into losses of about 14 mg h(-1) for HFC-134a and 20-30 mg h(-1) for CFC-12, when the estimated distribution of HFC-134a-A/C-units (45%) and CFC-12-A/C-units (3-5%) in the car fleet were taken into account. The emissions of CFC-12 and HFC-134a were mainly attributed to the losses from A/C-systems of passenger cars, whereas the emissions of HCFC-22 originate from losses of refrigeration systems of transport trucks. The observed emissions are discussed in respect to their environmental impact and compared to the overall greenhouse gas emissions of road traffic. PMID:15112799

Stemmler, Konrad; O'Doherty, Simon; Buchmann, Brigitte; Reimann, Stefan

2004-04-01

49

GAS CHROMATOGRAPHIC RETENTION PARAMETERS DATABASE FOR REFRIGERANT MIXTURE COMPOSITION MANAGEMENT  

EPA Science Inventory

Composition management of mixed refrigerant systems is a challenging problem in the laboratory, manufacturing facilities, and large refrigeration machinery. Ths issue of composition management is especially critical for the maintenance of machinery that utilizes zeotropic mixture...

50

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

Microsoft Academic Search

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

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

1997-01-01

51

Releases of refrigerant gases (CFC12, HCFC22 and HFC134a) to the atmosphere  

Microsoft Academic Search

Two of the gases, CFC-12 (dichlorodifluoromethane, CF2Cl2) and HCFC-22 (chlorodifluoromethane, CHClF2) have long histories of emission from refrigeration and other uses. Production and sales records show the expected fall in the amounts of CFC-12 used in refrigeration after the Montreal Protocol came into effect but this does not seem to have been accompanied by significant substitution by HCFC-22, demand for

Archie McCulloch; Pauline M Midgley; Paul Ashford

2003-01-01

52

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.

53

Viscosity of Gaseous Mixtures of HFC-125 + Propane from 298.15 to 423.15 K at Pressures to 6.7 MPa  

NASA Astrophysics Data System (ADS)

This paper reports experimental results for the viscosity of gaseous mixtures of HFC-125 (pentafluoroethane) + propane. The measurements were carried out with an oscillating-disk viscometer of the Maxwell type at temperatures from 298.15 to 423.15 K. The viscosity was measured for two mixtures containing 50.11 and 75.03 mol% HFC-125 in propane. The viscosity at normal pressure was analyzed with the extended law of corresponding states developed by Kestin et al., and the scaling parameters were obtained for unlike-pair interactions between HFC-125 and propane. The modified Enskog theory developed by Vesovic and Wakeham was applied to predict the viscosity for the binary gaseous mixtures under pressure. From comparisons between experimental results and calculated values of the HFC-125 + propane system, it should be concluded that the Vesovic-Wakeham method gives reliable predictions for the viscosity of a gaseous mixture containing both polar and nonpolar compounds.

Yokoyama, C.; Nishino, T.; Takahashi, M.

2006-05-01

54

Compatibility of lubricant additives with HFC refrigerants and synthetic lubricants. Final report, Part 1  

SciTech Connect

Part one of this research provides manufacturers of components of air-conditioning and refrigeration equipment with a useful list of lubricant additives, sources, functional properties and chemical species. The list in part one is comprised of domestic lubricant additive suppliers and the results of a literature search that was specifically targeted for additives reported to be useful in polyolester chemistry.

Cavestri, R.C. [Imagination Resources, Inc., Dublin, OH (United States)

1997-07-01

55

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

56

Two-phase heat transfer coefficients of three HFC refrigerants inside a horizontal smooth tube, part I: evaporation  

Microsoft Academic Search

This paper presents experimental heat transfer results obtained during the evaporation of Isceon 59, R407C and R404A in a horizontal tube. The results have been compared with existing correlations which characterise the evaporative heat transfer coefficient to assess the validity of these models for refrigerant mixtures. The results compared well with the (Gungor K.E., Winterton, R.H.S. Simplified general correlation for

X. Boissieux; M. R. Heikal; R. A. Johns

2000-01-01

57

P?Tx measurements for HFC134a + triethylene glycol dimethylether system  

Microsoft Academic Search

Experimental densities in the compressed liquid phase are reported for 1,1,1,2-tetrafluoroethane (HFC-134a), triethylene glycol dimethylether (TriEGDME) and six of their mixtures from 293.15 to 373.15K and at pressures up to 60MPa. From the experimental results, we have analysed the volumetric behaviour of HFC-134a+TriEGDME. In almost all the measurement range, the density of the refrigerant is greater than that of the

M. J. P. Comuñas; J. Fernández; A. Baylaucq; X. Canet; C. Boned

2002-01-01

58

Azeotropy in the natural and synthetic refrigerant mixtures  

Microsoft Academic Search

A novel approach for the prediction of azeotrope formation in a mixture that does not require vapour–liquid equilibrium calculations is developed. The method employs neural networks and global phase diagram methodologies to correlate azeotropic data for binary mixtures based only on critical properties and acentric factor of the individual components in refrigerant mixtures. Analytical expressions to predict azeotropy and double

Sergey Artemenko; Victor Mazur

2007-01-01

59

Testing of propane\\/isobutane mixture in domestic refrigerators  

Microsoft Academic Search

The performance of a propane\\/isobutane (R290\\/R600a) mixture was examined for domestic refrigerators. A thermodynamic cycle analysis indicated that the propane\\/isobutane mixture in the composition range of 0.2 to 0.6 mass fraction of propane yields an increase in the coefficient of performance (COP) of up to 2.3% as compared to CFC12. For the actual tests, two commercial refrigerators of 299 and

Dongsoo Jung; Chong-Bo Kim; Kilhong Song

2000-01-01

60

The application of propane\\/butane mixture for domestic refrigerators  

Microsoft Academic Search

This work investigates the result of an experimental study carried out to determine the performance of a domestic refrigerator when a propane\\/butane mixture is used as a possible replacement to the traditional refrigerant CFC 12. The used propane\\/butane mixture is liquefied petroleum gas (LPG) which is locally available and comprises 24.4% propane, 56.4% butane and 17.2% isobutane. The LPG is

M. A. Alsaad; M. A. Hammad

1998-01-01

61

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

NASA Technical Reports Server (NTRS)

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

Westra, Douglas G.

1993-01-01

62

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

63

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

64

Foaming characteristics of refigerant/lubricant mixtures  

SciTech Connect

The air-conditioning and refrigeration industry has moved to HFC refrigerants which have zero ozone depletion and low global warming potential due to regulations on CFC and HCFC refrigerants and concerns for the environment. The change in refrigerants has prompted the switch from mineral oil and alkylbenzene lubricants to polyolester-based lubricants. This change has also brought about a desire for lubricant, refrigerant and compressor manufacturers to understand the foaming properties of alternative refrigerant/ lubricant mixtures, as well as the mechanisms which affect these properties. The objectives of this investigation are to experimentally determine the foaming absorption and desorption rates of HFC and blended refrigerants in polyolester lubricant and to define the characteristics of the foam formed when the refrigerant leaves the refrigerant/ lubricant mixture after being exposed to a pressure drop. The refrigerants being examined include baseline refrigerants: CFC-12 (R-12) and HCFC-22 (R-22); alternative refrigerants: HFC-32 (R-32), R-125, R-134a, and R-143a; and blended refrigerants: R-404A, R-407C, and R-410A. The baseline refrigerants are tested with ISO 32 (Witco 3GS) and ISO 68 (4GS) mineral oils while the alternative and blended refrigerants are tested with two ISO 68 polyolesters (Witco SL68 and ICI RL68H).

Goswami, D.Y.; Shah, D.O.; Jotshi, C.K.; Bhagwat, S.; Leung, M.; Gregory, A.

1997-04-01

65

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...

66

Simulation and Test Results of Hydrocarbon Mixtures in a Modified-Lorenz-Meutzner Cycle Domestic Refrigerator  

Microsoft Academic Search

In an effort to minimize the energy consumption of domestic refrigerators\\/freezers with environmentally safe refrigerants, one R-22\\/123 mixture and three hydrocarbon mixtures were theoretically and experimentally investigated in a modified-Lorenz-Meutzner cycle refrigerator. All the measured and simulated performance improvements reported in the present paper are with reference to the performance of a conventional single-evaporator R-12 refrigerator-freezer system. The computer simulation

Zhijing Liu; Imam Haider; Reinhard Radermacher

1995-01-01

67

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

68

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

69

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

70

Performance analysis of the natural mixture R744\\/R600a refrigeration cycle  

Microsoft Academic Search

Environmental conservation issue advances the refrigerant substitute for the Freons. Natural working fluid must be a perfect choice. Therefore, natural friendly refrigerants R744 and R600a are selected in this research to be a binary mixture. Such a mixture can weaken their shortcomings by decreasing high heat rejection pressure as that of pure R744, and reducing flammability as that of pure

Xianping Zhang; Aidong Chen; Huanlin Duan

2010-01-01

71

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

NASA Astrophysics Data System (ADS)

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 (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 (approximately 3 percent) are seen for the NARM over R-12 in the same refrigerator freezer circuit. Modeling results and steady-state data suggest larger improvements (approximately 15 percent) 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.

72

Zero-ODP refrigerants for low tonnage centrifugal chiller systems  

SciTech Connect

This paper investigates the use of several zero-ozone depleting potential (zero-ODP) HFC refrigerants, including HFC-134a, HFC-227ca, HFC-227ea, HFC-236cb, HFC-236fa, HFC-245cb, and HFC-254cb for centrifugal chiller applications. The authors took into account the thermodynamic properties of the refrigerant and aerodynamic characteristics of the impeller compression process in this evaluation. For a given operating temperature lift, there are significant differences in the enthalpy rise required by each refrigerant and this variation in enthalpy rise directly affects compressor size, efficiency, and performance. A comparison of the HFC refrigerant candidates with CFC-114 shows that HFC-236ea, HFC-227ca and HFC-227ea are viable alternatives for centrifugal water chillers, HFC-236ea has properties closest to CFC-114, and will result in comparable performance, but will require a slightly larger impeller and a purge system. Using HFC-227ca or HFC-227ea results in a significantly lower enthalpy rise requirement, potentially allowing single-stage compression, however, wet compression could be a problem. Single-stage compression gives an overall performance advantage over CFC-114 (operating with 3--5 C of liquid subcooling), and when considering thermodynamics and aerodynamics, as is necessary in centrifugal applications, the authors find that HFC-227ca and HFC-227ea have additional advantages over HFC-236ea and CFC-114.

Gui, F.; Back, D.D.; Scaringe, R.P.; Grzyll, L.R.

1996-12-31

73

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...

74

Experimental study of the refrigeration cycle performance for the R744\\/R290 mixtures  

Microsoft Academic Search

A new binary mixture of R744 and R290 as an alternative natural refrigerant to R13 was first presented in this paper. Its environmental performance is friendly. It has an ODP of zero and GWP smaller than 20. Experimental studies for this mixture and R13 were performed on a cascade refrigeration system only with modification to capillary in low-temperature circuit. COP

Baolian Niu; Yufeng Zhang

2007-01-01

75

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

76

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

EPA Science Inventory

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

77

Thermodynamic Properties of the Mixtures R23\\/R744 and R41\\/R744 and their Efficiency as Refrigerants  

Microsoft Academic Search

Mixtures of refrigerants are widely used as working substances for refrigerating plants. Among them, mixtures of ozone-safe and natural refrigerants, in particular R23\\/R744 and R41\\/R744, are important. For calculating their thermodynamic properties, we compiled equations of state on the basis of the method in (1). According to this reference, the equation of state for a mixture is presented as a

Aleksandr Vasserman C; Valentine Malchevsky S

78

Experimental investigation of low-pressure refrigerant mixtures for micro cryogenic coolers  

NASA Astrophysics Data System (ADS)

Micro Cryogenic Coolers (MCCs) can achieve very small sizes and high efficiencies when operating with a refrigerant mixture, but micro-scale compressors have a limited pressure output. Four refrigerant mixtures were designed to operate between 0.4 MPa and 0.1 MPa, and tested in a MCC system both with and without pre-cooling. For comparison, two pure refrigerants were tested as well. Without pre-cooling, each mixture exhibited considerably lower cooling power than the design value. With pre-cooling, the mixtures exhibited unsteady cooling temperatures accompanied by flow pulsations after a period of time. The low cooling power, unsteady temperatures, and time required for the pulsations to occur are analyzed in terms of composition change due to liquid hold-up in the annular and intermittent flow regimes.

Lewis, Ryan; Wang, Yunda; Bradley, Peter E.; Huber, Marcia L.; Radebaugh, Ray; Lee, Y. C.

2013-02-01

79

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...

80

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...

81

CO 2 Compressors for Light Commercial Refrigeration  

Microsoft Academic Search

1. ABSTRACT HFC refrigerant has been identified as a contributing factor with regard to global warming. This fact has put pressure on most of the refrigeration industry to replace the HFC refrigerant fluids currently employed in vapor compression systems. In this search for an environmental friendly technology, Carbon Dioxide (CO 2) has emerged as a leading candidate to be a

Ricardo A. Maciel; Marino Bassi

82

Performance Analysis of heat pump cycle using CO2/DME refrigerant mixture  

NASA Astrophysics Data System (ADS)

Performance analyses have been carried out for a heat pump cycle using zeotropic refrigerant mixtures of carbon dioxide (CO2) and dimethyl ether (DME). In order to clarify the characteristics and coefficient of performance (COP) of CO2/DME heat pump cycle, the concentration of mixture was varied over a wide range. The calculation conditions were established as a hot-water supply system and the calculations were conducted by considering the heat transfer between the refrigerant and heat source/sink water. Because the heat transfer between refrigerant and heat source/sink water strongly affects on the cycle behavior, effects of the heat transfer capability parameter were investigated. The heat pump cycle is formed around the critical point for high CO2 concentration mixtures and it is formed under the critical point for low CO2 concentration mixtures. The COP has the maximum at a certain pressure for each mixture and the COPs of the mixture and pure DME are higher than that of pure CO2. Operating pressure decreases with increase of DME concentration. The effects of heat transfer between the refrigerant and heat source/sink water on characteristics of the cycle have also been clarified.

Onaka, Yoji; Miyara, Akio; Tsubaki, Koutaro; Koyama, Shigeru

83

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...

84

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

85

Human Safety and Pharmacokinetics of the CFC Alternative Propellants HFC 134a (1,1,1,2-Tetrafluoroethane) and HFC 227 (1,1,1,2,3,3,3-Heptafluoropropane) Following Whole-Body Exposure  

Microsoft Academic Search

HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3,3-heptafluoropropane) are used to replace chlorofluorocarbons (CFCs) in refrigerant and aerosol applications, including medical use in metered-dose inhalers. Production and consumption of CFCs are being phased out under the Montreal Protocol on Substances that Deplete the Ozone Layer. The safety and pharmacokinetics of HFC 134a and HFC 227 were assessed in two separate double-blind

H. H. Emmen; E. M. G. Hoogendijk; W. A. A. Klöpping-Ketelaars; H. Muijser; E. Duistermaat; J. C. Ravensberg; D. J. Alexander; D. Borkhataria; G. M. Rusch; B. Schmit

2000-01-01

86

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

Code of Federal Regulations, 2014 CFR

...possibility of refrigerant contamination from hydrocarbons, leak sealants...also shall alert to possible contamination problems to the recovery...45 000 ppm (by weight) of oil (polyalkylene glycol oil with 46-160 cst...

2014-07-01

87

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

...possibility of refrigerant contamination from hydrocarbons, leak sealants...also shall alert to possible contamination problems to the recovery...45 000 ppm (by weight) of oil (polyalkylene glycol oil with 46-160 cst...

2012-07-01

88

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

...possibility of refrigerant contamination from hydrocarbons, leak sealants...also shall alert to possible contamination problems to the recovery...45 000 ppm (by weight) of oil (polyalkylene glycol oil with 46-160 cst...

2011-07-01

89

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

...possibility of refrigerant contamination from hydrocarbons, leak sealants...also shall alert to possible contamination problems to the recovery...45 000 ppm (by weight) of oil (polyalkylene glycol oil with 46-160 cst...

2010-07-01

90

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

...possibility of refrigerant contamination from hydrocarbons, leak sealants...also shall alert to possible contamination problems to the recovery...45 000 ppm (by weight) of oil (polyalkylene glycol oil with 46-160 cst...

2013-07-01

91

The performance of propane\\/isobutane mixtures in a vapour-compression refrigeration system  

Microsoft Academic Search

Experiments have been conducted to investigate the performance of hydrocarbon refrigerants in a hermetic vapour-compression system. It is shown that propane and propane\\/isobutane mixtures may be used in an unmodified R12 system and give better COPs than R12 under the same operating conditions.

R. N. Richardson; J. S. Butterworth

1995-01-01

92

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

93

Review of secondary loop refrigeration systems  

Microsoft Academic Search

Due to the environmental damage caused by HFC refrigerants, there is an increasing universal interest to research environmentally friendly fluids in refrigerants and alternative approaches to the traditional DX refrigeration system. These refrigerants include ammonia, carbon dioxide, hydrocarbon, R152a and HFO1234yf. Major drawbacks of these refrigerants are their potential flammability and safety hazards. One way to overcome this issue is

Kai Wang; Magnus Eisele; Yunho Hwang; Reinhard Radermacher

2010-01-01

94

Thermodynamic calculations for mixtures of environmentally safe refrigerants using the Lee-Kesler-Ploecker equation of state  

SciTech Connect

The imminent phaseout of R-11, R-12, and R-115 because of their high ozone depletion potentials has prompted many independent investigations of alternative or substitute refrigerants, either as pure compounds or as mixtures of two or more environmentally acceptable fluids. There are several motivations for investigating mixtures. There are very few pure compounds which can be used for refrigerants that are non-toxic, non-flammable, and also have very low ozone depleting potentials (ODP) and greenhouse warming potentials (GWP). Mixtures composed of three or more components offer a distinct advantage in that careful selection of the components could permit a flammable refrigerant to be used in a blend that remains non-flammable under all conceivable conditions. Also, component concentrations in ternary or higher order mixtures can be adjusted to linearize the temperature-enthalpy profile of a mixture making it more suitable for applications where secondary fluids are heated or cooled through large temperature glides (i.e., refrigeration and air conditioning). The computer model LKPSIM was constructed from subroutines written by Ulf Ploecker and incorporated into a Lorenz cycle refrigerator/freezer simulation model for binary refrigerant mixtures developed at the University of Hannover. Modifications were made to the Hannover routines to compute thermodynamic properties for mixtures of three or more components, the list of available refrigerants was expanded from 11 to 17 possible choices, and a new correlation was developed for computing the interaction coefficients for mixtures of halocarbon refrigerants. Tables of refrigerant molecular weights, critical temperatures and pressures, normal boiling points, acentric factors, and coefficients for fits to the ideal gas heat capacity for each refrigerant are built into a menu-driven data input routine for ease of use. 11 refs., 6 figs., 2 tabs.

Fischer, S.K.; Sand, J.R.

1990-01-01

95

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

96

Lubricants for HFC-134a Compatible Rotary Compressors  

NASA Astrophysics Data System (ADS)

In replacing CFC-12 with HFC-134a for refrigerator compressors, the compatibility with lubricating oil, and lubrication in general, are of major concern. HFC-134a dose not have adequate solubility with current lubricating oils because of its molecular structure. Current oils also do not provide enough lubricating action when using HFC-134a. A new oil and new materials have to be utilized in order to use HFC-134a. Developing a new lubricating oil involved numerous tests of different combinations of many polyolester synthetic oils and additives. One of the pre-evaluated methods was pursued via sealed tube tests. Lubricated parts were selected by studies involving a plane-on-roller type of wear test machine and by analyzing the traces of acid material commonly created during the lubricating action. The matrices of new lubricating oils and new lubricated materials were estimated based on durability tests conducted on compressors and refrigerators. Results showed that polyolester synthetic oils having a low total acid value and including certain quantities of additives did not break down into a tar-like substance and they did not produce composite particles in the operating compressors and refrigerators. The study also found that ceramics and anti-corrosion alloy steel possessed good adrasion-reducing qualities. Based on our evaluation, we will implement compressor reliability tests and apply HFC-134a to rotary compressors for refrigerators.

Takaichi, Kenji; Sakai, Hisakazu

97

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...

98

Evaluation of capillary tube performance for CFC-12 and HFC-134a  

SciTech Connect

The paper presents comparison in flow characteristics for CFC-12 and HFC-134a in capillary tube. The results revealed that even with minor differences in refrigerant properties between CFC-12 and HFC-134a, the differences in flow characteristics may be significant. Theoretical results predicted that 15% difference or more in critical tube length may be expected.

Wong, T.N.; Ooi, K.T. [Nanyang Technological Univ., Singapore (Singapore). School of Mechanical and Production Engineering] [Nanyang Technological Univ., Singapore (Singapore). School of Mechanical and Production Engineering

1996-11-01

99

Tribological evaluation of some aluminum-based materials in lubricant\\/refrigerant mixtures  

Microsoft Academic Search

The tribological characteristics of various aluminum alloys, surface treated 356 aluminum alloy and an aluminum composite are evaluated in lubricant\\/refrigerant (L\\/R) mixtures. The evaluation is based on a cylindrical pin\\/disc line contact geometry. This research program consists of two parts. The first part focuses mainly on materials screening of various aluminum\\/steel contact pairs lubricated by polyolester\\/R134a (tetrafluoroethane) and polyalkylene glycol

Hyung Yoon; Todor Sheiretov; Cris Cusano

1998-01-01

100

Accelerated screening methods for determining chemical and thermal stability of refreigerant-lubricant mixtures. Part II: Experimental comparison and verification of methods. Final report, volume I  

SciTech Connect

The research reported herein was performed to develop an accelerated screening method for determining the chemical and thermal stabilities of refrigerant/lubricant mixtures. The developed screening method was designed to be safe and to produce accelerated stability rankings that are in agreement with the rankings determined by the current test, Sealed Glass Tube Method to Test the Chemical Stability of Material for Use Within Refrigerant Systems, ANSI/ASHRAE Method 97-1989. The accelerated screening test developed was designed to be independent of refrigerant and lubricant compositions and to be used with a wide variety of construction materials. The studied refrigerants included CFC-11, CFC-12, HCFC-22, HFC-134a, and HFC-32/HFC-134a (zeotrope 30:70 by weight). The studied lubricants were selected from the chemical classes of mineral oil, alkylbenzene oil, polyglycols, and polyolesters. The work reported herein was performed in three phases. In the first phase, previously identified thermal analytical techniques were evaluated for development into an accelerated screening method for refrigerant/lubricant mixtures. The identified thermal analytical techniques used in situ measurements of color, temperature, or conductivity to monitor the degradation of the heated refrigerant/lubricant mixtures. The identified thermal analytical techniques also used catalysts such as ferric fluoride to accelerate the degradation of the heated refrigerant/lubricant mixtures. The thermal analytical technique employing in situ conductivity measurements was determined to be the most suitable for development into an accelerated screening method.

Kauffman, R. [Univ. of Dayton Research Institute, Dayton, OH (United States)

1995-09-01

101

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

102

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

103

Pool boiling heat transfer of refrigerant mixtures R32/R125  

SciTech Connect

Nucleate pool boiling heat transfer of new, environmentally harmless refrigerant mixtures R32/R125 has been systematically investigated in a wide range of pressure and heat flux under saturation conditions using a horizontal platinum wire (d = 0.1 mm). The platinum wire served as both heating element and resistance thermometer. The experimental results are compared with calculated values using a modified Jungnickel correlation. The comparison between all calculated data and experimental data shows good agreement. Most of the data fall within {+-}20% of the correlation. The mean average deviation is {+-}8.25%.

Shen, J.; Spindler, K.; Hahne, E.

1999-11-01

104

Compatibility of refrigerants and lubricants with motor materials  

SciTech Connect

During the compatibility study of 10 pure refrigerants with 24 motor materials, it was observed that the greatest damage to the insulation system was caused by absorption of refrigerant followed by rapid desorption. The observed effects were blisters, cracking, internal bubbles and delamination. Measured results includes decreased bond strength, dielectric strength and overall integrity of the material. Refrigerants HCFC-22, HFC-32, HFC-134 and HFC-152a exhibited this phenomena. The effect of HCFC-22 was most severe of the tested refrigerants. Since HCFC-22 has an excellent reliability history with many of the materials tested, compatibility with the new refrigerants is expected.

Doerr, R.; Kujak, S.

1992-10-01

105

Occupational exposure to fluorinated hydrocarbons during refrigeration repair work.  

PubMed

This study describes refrigeration repair workers' occupational exposures to halogenated refrigerants, focusing on difluorochloromethane (HCFC 22), tetrafluoroethane (HFC 134a) and a mixture of tri-, tetra- and pentafluoroethane (R404A) in 30 work operations. Unlike earlier reported studies, the present study includes working procedures involving welding in order to measure possible occupational exposure to decomposition products. The measurements included hydrogen fluoride (HF), hydrogen chloride (HCl), phosgene (COCl2) and volatile organic compounds (VOC). The exposures were assessed during work operations on small-scale cooling installations like refrigerators and freezers. The repair workers' occupational exposures to refrigerants were moderate, and the major part of the exposures were associated with specific working procedures lasting for relatively short periods of time (<20 min). During these exposure events the concentrations were occasionally high (up to 42434 mg m(-3)). Although welding operations lasted only for short periods of time, HF was detected in 9 out of 15 samples when HCFC 22, HFC 134a or R404A had been used. Hydrogen chloride was detected in 3 out of 5 samples in air polluted with HCFC 22. Phosgene was not detected. A large number of VOCs in various concentrations were found during welding. Except for the applied refrigerants, halogenated compounds were only found in one sample. PMID:12729261

Gjølstad, Merete; Ellingsen, Dag G; Espeland, Oscar; Nordby, Karl-Christian; Evenseth, Harald; Thorud, Syvert; Skaugset, Nils Petter; Thomassen, Yngvar

2003-04-01

106

Thermal conductivity of alternative refrigerants in the liquid phase  

NASA Astrophysics Data System (ADS)

Measurements ofthe thermal conductivity of five alternative refrigerants. namely, difluoromethane HFC-321. pentafluoroethane (HFC-125), 1,1,1-trifluoroethane (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 HCFC-225ca, and 286 345 K for HCFC-225cb, The pressure rank 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 ofeach 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.; Kobayashi, K.; Minamiyama, T.

1996-05-01

107

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

108

International Journal of Thermophysics, Vol. 20, No. 1, 1999 Vapor-Liquid Equilibria of Alternative Refrigerants  

E-print Network

Refrigerants by Molecular Dynamics Simulations1 M. Lisal,2 R. Budinsky,3 V. Vacek,3 and K. Aim2, 4 Alternative refrigerants HFC-152a (CHF2CH3), HFC-143a (CF3CH3), HFC- 134a (CF3CH2F), and HCFC-142b (CF2ClCH3) are modeled Republic. 4 To whom correspondence should be addressed. KEY WORDS: alternative refrigerants; Gibbs

Lisal, Martin

109

Blends of carbon dioxide and HFCs as working fluids for the low-temperature circuit in cascade refrigerating systems  

Microsoft Academic Search

This paper describes an analysis on the performances of a cascade refrigeration cycle operated with blends of carbon dioxide (CO2, or R744) and hydrofluorocarbons (HFC) as the low-temperature working fluid. The aim of this work was to study the possibility of using carbon dioxide mixtures in those applications where temperatures below CO2 triple point (216.58K) are needed. The analysis was

Giovanni Di Nicola; Giuliano Giuliani; Fabio Polonara; Roman Stryjek

2005-01-01

110

COMPARISON OF CFC-114 AND HFC-236EA PERFORMANCE IN SHIPBOARD VAPOR COMPRESSION SYSTEMS  

EPA Science Inventory

The report gives results of a comparison of the performance of two refrigerants - 1,1,1,2,3,3-hexafluoropropane (HFC-236ea) and 1,2-dichloro-tetrafluoroethane (CFC-114) - in shipboard vapor compression refrigeration systems. (NOTE: In compliance with the Montreal Protocol and Dep...

111

Solubility, viscosity and density of refrigerant/lubricant mixtures. Final technical report, [1 October 1992--19 April 1994  

SciTech Connect

This report presents the results of experimental measurements on low refrigerant concentration mixtures (0, 10, 20 and 30 weight percent) and high refrigerant concentration mixtures (80, 90 and 100 weight percent) of chlorofluorocarbon (CFC) 12, hydrochlorofluorocarbons (HCFC`s) 22, 123, 124 and 142b, and hydrofluorocarbons (BFC`s) 134a, 32, 125, 152a and 143a with mineral oil, alkylbenzene, polyalkylene glycol and polyolester lubricants. Viscosity, solubility (vapor pressure) and density data are reported for thirty five working fluids which are selected combinations of these refrigerants and companion lubricants. These data, reduced to engineering form, are presented in the form of a Daniel Chart and a plot of density versus temperature and composition. Extensive numerical analysis has been performed in order to derive equations which allow two independent variables (temperature and composition) and to provide for corrections in composition due to vapor space volume in the test apparatus.

Henderson, D.R.

1994-04-01

112

A refrigeration system for supermarkets using natural refrigerant CO 2  

Microsoft Academic Search

This paper describes a refrigeration system using a natural refrigerant that has been developed to reduce significantly both direct and indirect greenhouse gas emissions. The new system uses both R-404A and CO2<\\/sub> (R-744) as refrigerants. The new system has very low global warming potential compared with conventional HFC systems which reduces significantly direct emissions. Indirect emissions are also much reduced

A. Campbell; G. G. Maidment; J. F. Missenden

2007-01-01

113

Immediate opportunity for large greenhouse gas emissions reductions with new mobile air conditioning refrigerants  

Microsoft Academic Search

Vehicle air conditioning, or “mobile air conditioning” (MAC), has a significant impact on the Earth's climate. HFC-134a, the predominant refrigerant in today's MAC, has a global warming potential (GWP) of 1430. MAC is responsible for a third of global HFC emissions and is the single largest user of HFC-134a. Fortunately, three technically and economically feasible low-GWP refrigerant alternatives exist, making

Kristen N. Taddonio

2010-01-01

114

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

115

Human safety and pharmacokinetics of the CFC alternative propellants HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3, 3-heptafluoropropane) following whole-body exposure.  

PubMed

HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3, 3-heptafluoropropane) are used to replace chlorofluorocarbons (CFCs) in refrigerant and aerosol applications, including medical use in metered-dose inhalers. Production and consumption of CFCs are being phased out under the Montreal Protocol on Substances that Deplete the Ozone Layer. The safety and pharmacokinetics of HFC 134a and HFC 227 were assessed in two separate double-blind studies. Each HFC (hydrofluorocarbon) was administered via whole-body exposure as a vapor to eight (four male and four female) healthy volunteers. Volunteers were exposed, once weekly for 1 h, first to air and then to ascending concentrations of HFC (1000, 2000, 4000, and 8000 parts per million (ppm)), interspersed with a second air exposure and two CFC 12 (dichlorodifluoromethane) exposures (1000 and 4000 ppm). Comparison of either HFC 134a or HFC 227 to CFC 12 or air gave no clinically significant results for any of the measured laboratory parameters. There were no notable adverse events, there was no evidence of effects on the central nervous system, and there were no symptoms of upper respiratory tract irritation. HFC 134a, HFC 227, and CFC 12 blood concentrations increased rapidly and in an exposure-concentration-dependent manner, although not strictly proportionally, and approached steady state. Maximum blood concentrations (C(max)) tended to be higher in males than females; in the HFC 227 study, these were statistically significantly (P < 0. 05) higher in males for each HFC 227 and CFC 12 exposure level. In the HFC 134a study, the gender difference in C(max) was only statistically significant (P < 0.05) for CFC 12 at 4000 ppm and HFC 134a at 8000 ppm. Following the end of exposure, blood concentrations declined rapidly, predominantly biphasically and independent of exposure concentration. For the HFC 134a study, the t(1/2)alpha (alpha elimination half-life) was short for both CFC 12 and HFC 134a (<11 min). The t(1/2)beta (beta elimination half-life) across all exposure concentrations was a mean of 36 and 42 min for CFC 12 and HFC 134a, respectively. Mean residence time (MRT) was an overall mean of 42 and 44 min for CFC 12 and HFC 134a, respectively. In the HFC 227 study, t(1/2)alpha for both CFC 12 and HFC 227, at each exposure level, was short (<9 min) and tended to be lower in males than females. For CFC 12 mean t(1/2)beta ranged from 23 to 43 min and for HFC 227 the mean range was 19-92 min. The values tended to be lower for females than males for HFC 227. For both CFC 12 and HFC 227, MRT was statistically significantly lower (P < 0.05) in males than females and independent of exposure concentration. For CFC 12, MRT was a mean of 37 and 45 min for males and females, respectively, and for HFC 227 MRT was a mean of 36 and 42 min, respectively. Exposure of healthy volunteers to exposure levels up to 8000 ppm HFC 134a, 8000 ppm HFC 227, and 4000 ppm CFC 12 did not result in any adverse effects on pulse, blood pressure, electrocardiogram, or lung function. PMID:11029265

Emmen, H H; Hoogendijk, E M; Klöpping-Ketelaars, W A; Muijser, H; Duistermaat, E; Ravensberg, J C; Alexander, D J; Borkhataria, D; Rusch, G M; Schmit, B

2000-08-01

116

Thermophysical Properties of the Refrigerant Mixtures R417A and R417B from Dynamic Light Scattering (DLS)  

NASA Astrophysics Data System (ADS)

Dynamic light scattering (DLS) has been used for the measurement of several thermophysical properties of the refrigerant mixtures R417A (50 % by mass 1,1,1,2-tetrafluoroethane—R134a, 46.6 % pentafluoroethane—R125, 3.4 % n-butane—R600) and R417B (79 % by mass R125, 18.25 % R134a, 2.75 % R600). Both refrigerant mixtures are designed for a replacement of R22 (chlorodifluoromethane) in existing refrigeration systems. Thermal diffusivity and sound speed have been obtained by light scattering from the bulk fluid for the liquid phase under saturation conditions over a temperature range from about 283 K up to the liquid-vapor critical point with estimated uncertainties between 1 % and 3 % and between 0.5 % and 2 %, respectively. By applying the method of DLS to a liquid-vapor interface, also called surface light scattering, the saturated liquid kinematic viscosity and surface tension have been determined simultaneously. These properties have been measured from 253.15 K up to the liquid-vapor critical point with estimated uncertainties between 1 % and 3 % for kinematic viscosity and between 1 % and 2 % for surface tension. The measured thermal diffusivity, sound speed, kinematic viscosity, and surface tension are represented by interpolating expressions with differences between the experimental and calculated values that are comparable with but always smaller than the uncertainties. The results are discussed in detail in comparison with literature data and with various prediction methods.

Heller, A.; Rausch, M. H.; Flohr, F.; Leipertz, A.; Fröba, A. P.

2012-03-01

117

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

SciTech Connect

During the compatibility study of 10 pure refrigerants with 24 motor materials, it was observed that the greatest damage to the insulation system was caused by absorption of refrigerant followed by rapid desorption. The observed effects were blisters, cracking, internal bubbles and delamination. Measured results includes decreased bond strength, dielectric strength and overall integrity of the material. Refrigerants HCFC-22, HFC-32, HFC-134 and HFC-152a exhibited this phenomena. The effect of HCFC-22 was most severe of the tested refrigerants. Since HCFC-22 has an excellent reliability history with many of the materials tested, compatibility with the new refrigerants is expected.

Doerr, R.; Kujak, S.

1992-10-01

118

How to convert CFC-12 chillers to HFC-134A  

SciTech Connect

With less than three years to go before CFC production comes to a halt, the need to retrofit, replace, or manage the containment of CFC-based HVAC systems is a pressing concern for everyone with equipment that runs on a CFC refrigerant today. For building owners and others whose properties are cooled by large tonnage centrifugal chillers operating on CFC, the problem is even more serious. The HVAC industry does not have the capacity to replace every centrifugal chiller currently running on CFCs with new, ozone-safe equipment prior to the December 31, 1995 phaseout deadline. After the phaseout date, CFC refrigerants will be both difficult to find and expensive to purchase. In addition, the possibility of a new equipment order bottleneck is very real as the demand for ozone-safe centrifugal chillers continues to grow in upcoming months. As a result, when retrofitting is feasible, it should be considered as an alternative to purchasing new equipment. This article discusses how one such conversion option - retrofitting with HFC-134a - pertains to centrifugal chillers that currently operate on CFC-12 or R-500. The author reviews the procedure, performance, and costs of an HFC-134a conversion and explain why owners of CFC-12 and R-500 machines should consider the many benefits retrofitting with HFC-134a can offer.

Bell, A.M. (SnyderGeneral Corp., Minneapolis, MN (United States))

1993-04-01

119

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

120

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...

121

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

122

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

Microsoft Academic Search

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

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

1996-01-01

123

Alternatives for CFC-12 refrigerant in automotive air conditioning. Report for October 1996-March 1997  

SciTech Connect

Ten refrigerants including CFC-12, HFC-134a, and eight refrigerant blends were tested in an instrumented automotive air-conditioning system designed for CFC-12. The refrigerants were compared at three test conditions for refrigeration capacity, coefficient of performance, compressor discharge pressure, compressor discharge temperature, and evaporator outlet pressure. The results were obtained by testing all the refrigerants in the same system under the same conditions, and the results provide an indication of the comparative performance of the refrigerants.

Jetter, J.J.; Delafield, F.R.

1997-12-31

124

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

125

Acute neurobehavioral effects in rats from exposure to HFC 134a or CFC 12.  

PubMed

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 567,000 ppm for 4 h; its potential for cardiac epinephrine sensitization in beagle dogs is acceptable (75,000 ppm); and its capacity to induce carcinogenicity or developmental disorders in animals is minimal. HFC 134a, with a serum half life estimated at 4-11 min, has been accepted for use as a propellant in metered-dose inhalant products, implying a low human toxicity risk from periodic brief exposures. There has been little published human or animal research evaluating possible neurobehavioral toxicity from longer HFC 134a exposures, as may be expected to occur in operational scenarios. In this study, male Wistar rats were exposed to various concentrations of HFC 134a or CFC 12 for up to 30 min while performing in either a rotarod/motorized running wheel apparatus or in an operant chamber The relative neurobehavioral toxicity of CFC 12 and its ozone-depleting substance replacement HFC 134a was assessed by comparing both gross motor system incapacitation and more subtle changes in ability to perform an operant discrimination task. It was shown that exposure to HFC 134a or CFC 12 concentrations from 40,000 to 470,000 ppm, for up to 30 min, induced neurobehavioral deficits in every subject, ranging from reduced operant efficiency to apparent anesthesia. For neurobehavioral endpoints examined in these experiments, HFC 134a inhalation was shown to induce deficits more rapidly, and at lower concentrations when compared to CFC 12 exposure. PMID:11405255

Ritchie, G D; Kimmel, E C; Bowen, L E; Reboulet, J E; Rossi, J

2001-04-01

126

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

127

Extraction of nitric acid and uranyl nitrate by TBP in HFC134a  

Microsoft Academic Search

It was found that commercial refrigerant HFC-134a (1,1,1,2-tetrafluoroethane) dissolves 19±2 and 25±2vol.% TBP at 1.2MPa and 25°C and at 2.8MPa and 80°C, respectively. The TBP solutions in HFC-134a effectively extract nitric acid; the [HNO3]:[TBP] molar ratio changes from 1.5:1 to 2.3:1. Experimental data showed that the recovery of uranium from uranyl nitrate in a single operation using TBP solutions in

A. Shadrin; V. Kamachev; A. Murzin; D. Shafikov

2007-01-01

128

Global emissions of the hydrofluorocarbons (HFCs) HFC-365mfc, HFC-245fa, HFC-227ea, and HFC-236fa based on atmospheric observations  

NASA Astrophysics Data System (ADS)

We report on the atmospheric measurements and global emissions of the hydrofluorocarbons (HFCs) HFC-365mfc (CH3CH2CF2CF3, 1,1,1,3,3-pentafluorobutane), HFC-245fa (CHF2CH2CF3, 1,1,1,3,3-pentafluoropropane), HFC-227ea (CF3CHFCF3, 1,1,1,2,3,3,3-heptafluoropropane), and HFC-236fa (CF3CH2CF3, 1,1,1,3,3,3-hexafluoropropane). These measurements are from in-situ observations at stations of AGAGE (Advanced Global Atmospheric Gases Experiment) and SOGE (System for Observations of Halogenated Greenhouse Gases in Europe), and from the Korean station Gosan. We also report on flask sample measurements from the Antarctic stations King Sejong and Troll, and extend our records back to the 1970s using archived air samples of both hemispheres. All data are used in a global 12-box 2-dimensional atmospheric transport model to derive global abundances and emission estimates. All four HFCs have strongly increased in the atmosphere in recent years with growth rates at nearly 10 %, resulting in dry air mole fractions at the end of 2009 of 0.49 ppt for HFC-365mfc, 1.00 ppt for HFC-245fa, and 0.51 ppt for HFC-227ea. HFC-236fa, for which we report the first atmospheric measurements, is less abundant and has grown to 0.069 ppt at the end of 2009. Our model results show rapidly growing emissions of HFC-365mfc and HFC-245fa after 2002 but surprisingly these have now started to decline to globally 2.7 kt/yr (HFC-365mfc) and 6.1 kt/yr (HFC-245fa). On the other hand HFC-227ea and HFC-236fa show uninterrupted growth in their emissions of 2.5 kt/yr and 0.2 kt/yr at the end of 2009.

Vollmer, M. K.; Miller, B. R.; Rigby, M. L.; Reimann, S.; Muhle, J.; Agage, Soge, Snu Members, Kopri Members

2010-12-01

129

Potential effects of HFC-152a on global ozone and climate  

SciTech Connect

The hydrofluorocarbon, CH[sub 3]CHF[sub 2], also referred to as HFC-152a, is being considered by the chemical industry for a variety of potential uses, including as a refrigerant, aerosol propellant, and foam blowing agent Many of these uses of HFC-152a will be as replacements for chlorofluorocarbons (CFCs) such as CFC-11 and CFC-12 that are of concern because of their effects on stratospheric ozone and on climate. The purpose of this paper is to review the current scientific understanding of the potential for HFC-152a to have an impact on the atmospheric environment, with emphasis on the potential effects on global ozone and climate.

Wuebbles, D.J.

1993-01-01

130

Potential effects of HFC-152a on global ozone and climate  

SciTech Connect

The hydrofluorocarbon, CH{sub 3}CHF{sub 2}, also referred to as HFC-152a, is being considered by the chemical industry for a variety of potential uses, including as a refrigerant, aerosol propellant, and foam blowing agent Many of these uses of HFC-152a will be as replacements for chlorofluorocarbons (CFCs) such as CFC-11 and CFC-12 that are of concern because of their effects on stratospheric ozone and on climate. The purpose of this paper is to review the current scientific understanding of the potential for HFC-152a to have an impact on the atmospheric environment, with emphasis on the potential effects on global ozone and climate.

Wuebbles, D.J.

1993-01-01

131

Relative permittivity measurements of 1,1,1,2-tetrafluoroethane (HFC 134a), pentafluoroethane (HFC 125), and difluoromethane (HFC 32)  

Microsoft Academic Search

The relative permittivity of HFC 134a, HFC 32, and HFC 125 was measured as a function of temperature and pressure, to cover the liquid and gaseous states. The temperature range studied was 303 to 403 K, and the pressure range was 4.0 to 30.0 MPa. The relative permittivity, ε, could be fitted to the reduced density ρ{sub r} using the

Andrew P. Abbott; Christopher A. Eardley; Richard Tooth

1999-01-01

132

Relative permittivity measurements of 1,1,1,2-tetrafluoroethane (HFC 134a), pentafluoroethane (HFC 125), and difluoromethane (HFC 32)  

SciTech Connect

The relative permittivity of HFC 134a, HFC 32, and HFC 125 was measured as a function of temperature and pressure, to cover the liquid and gaseous states. The temperature range studied was 303 to 403 K, and the pressure range was 4.0 to 30.0 MPa. The relative permittivity, {epsilon}, could be fitted to the reduced density {rho}{sub r} using the function ({epsilon} {minus} 1)/(2{epsilon} + 1). The dipole moment of HFC 134 a in the liquid phase has been calculated.

Abbott, A.P.; Eardley, C.A.; Tooth, R. [Leicester Univ. (United Kingdom). Chemistry Dept.] [Leicester Univ. (United Kingdom). Chemistry Dept.

1999-01-01

133

Retrofitting an automotive air conditioner with HFC-134a, additive, and mineral oil. Final report, October 1992-May 1994  

SciTech Connect

The paper gives results of an evaluation of a lubricant additive developed for use in retrofitting motor vehicle air conditioners. The additive was designed to enable HFC-134a to be used as a retrofit refrigerant with the existing mineral oil in CFC-12 systems. The goal of the project was to provide preliminary feasibility testing of the additive. The cooling effect of the test system retrofitted with HFC-134a and the oil additive was nearly the same as that of the original system with CFC 12 refrigerant. If lubricant additives prove to be successful, miscible lubricants may not be needed for retrofitting some automotive systems. The retrofitting procedure might be simplified and the cost to consumers might be reduced. It has not been determined if retrofitting systems with HFC-134a and oil additives is feasible for a wider range of operating conditions and types of equipment, including the applicability of orifice tube/suction accumulator systems.

Jetter, J.J.; Delafield, F.R.

1994-05-01

134

Friction and wear of the lubricated vane and roller materials in a carbon dioxide refrigerant  

Microsoft Academic Search

Due to environmental concerns, carbon dioxide (CO2), a natural refrigerant, is an attractive alternative refrigerant to replace the current HFC refrigerants that are used in air conditioning systems. This paper investigated the friction and wear characteristics of sliding surfaces between a vane and an orbiting roller in a compressor in order to develop a new compressor, and especially a rotary

Hong-Gyu Jeon; Se-Doo Oh; Young-Ze Lee

2009-01-01

135

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.

136

Two-phase flow of HFC-134a and CFC-12 through short-tube orifices  

SciTech Connect

Short-tube orifices have been widely used as an expansion device on automotive and residential-sized air conditioners in the United States. The design for optimum performance of these systems requires predicting correct flow characteristics through short tubes for a given set of operating conditions. Insufficient data are available on how any of the new replacement refrigerants will perform in short-tube orifices relative to conventional refrigerants. This paper compares experimental mass flow results with HFC-134a and CFC-12 for a variety of inlet conditions and short-tube geometries. Five sharp-edged short-tube orifices with 7 < LID < 20 and 1.10 mm (0.0435 in.) < D < 1.72 mm (0.0676 in.) were tested with HFC-134a and CFC-12. Both two-phase and subcooled liquid flow conditions entering the short tube were examined for condensing temperatures ranging from 35.4 C (96 F) to 53.8 C (129 F), for subcooling as high as 13.9 C (25 F), and for qualities as high as 10% at the inlet of the short tube. The effects of downstream pressure were also investigated by lowering the downstream pressure from the upstream saturation pressure down to 310 kPa (45 psia). For HFC-134a, two types of measurements were made during this study-mass flow tests and pressure distribution inside the orifice. For CFC-12, only mass flow tests were performed The results with CFC-12 were compared with those of HFC-134a with the same upstream temperature conditions. A comparison of these two refrigerants was made as a function of the main operating variables (upstream pressure, subcooling, and downstream pressure) and short-tube geometry. Semi-empirical models for both HFC-134a and CFC-12 were developed for the prediction of mass flow rate through short tubes.

Kim, Y.; O`Neal, D.L. [Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering; Yuan, X. [Xi`an Jiatong Univ., Xi`an (China). Dept. of Power Machinery

1994-12-31

137

Reproductive and developmental toxicity of hydrofluorocarbons used as refrigerants.  

PubMed

The present paper summarizes data on the reproductive and developmental toxicity of hydrofluorocarbons (HFCs), including pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), difluoromethane (HFC-32) and 1,1,1,3,3-pentafluoropropane (HFC-245fa), used as refrigerants, published in openly available scientific literature. No developmental toxicity of HFC-125 was found even at 50,000 ppm in rats or rabbits. Although HFC-134a exhibited no dominant lethal effect or reproductive toxicity in rats, it caused low body weight in pre- and postnatal offspring and slightly retarded skeletal ossification in fetuses at 50,000 ppm in rats. No maternal or developmental toxicity was noted after exposure to HFC-143a even at 40,000 ppm in rats or rabbits or HFC-152a even at 50,000 ppm in rats. HFC-32 is slightly maternally and developmentally toxic at 50,000 ppm in rats, but not in rabbits. HFC-245fa caused decreases in maternal body weight and food consumption at 10,000 and 50,000 ppm and fetal weight at 50 000ppm. No evidence of teratogenicity for these HFCs was noted in rats or rabbits. There is limited information about the reproductive toxicity of these HFCs. Animal studies remain necessary for risk assessments of chemicals because it is difficult to find alternative methods to determine the toxic effects of chemicals. It is required to reduce emissions of organic vapors containing HFCs to reduce the risk of exposure. PMID:19914373

Ema, Makoto; Naya, Masato; Yoshida, Kikuo; Nagaosa, Ryuichi

2010-04-01

138

Design and simulation of a heat pump for simultaneous heating and cooling using HFC or CO2  

E-print Network

as a working fluid Paul BYRNE, Jacques MIRIEL, Yves LENAT paul.byrne@univ-rennes1.fr Equipe MTH ­ Laboratoire LGCGM - INSA de Rennes 20 avenue des buttes de Coësmes - CS 14 315 - 35 043 Rennes Cedex ­ France Tel refrigerants are studied: HFC R407C and carbon dioxide. HFCs provide good performance, but new restrictive

Paris-Sud XI, Université de

139

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

140

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

NASA Astrophysics Data System (ADS)

We report on ground-based atmospheric measurements and emission estimates of the four anthropogenic hydrofluorocarbons (HFCs) HFC-365mfc (CH3CF2CH2CF3, 1,1,1,3,3-pentafluorobutane), HFC-245fa (CHF2CH2CF3, 1,1,1,3,3-pentafluoropropane), HFC-227ea (CF3CHFCF3, 1,1,1,2,3,3,3-heptafluoropropane), and HFC-236fa (CF3CH2CF3, 1,1,1,3,3,3-hexafluoropropane). In situ measurements are from the global monitoring sites of the Advanced Global Atmospheric Gases Experiment (AGAGE), the System for Observations of Halogenated Greenhouse Gases in Europe (SOGE), and Gosan (South Korea). We include the first halocarbon flask sample measurements from the Antarctic research stations King Sejong and Troll. We also present measurements of archived air samples from both hemispheres back to the 1970s. We use a two-dimensional atmospheric transport model to simulate global atmospheric abundances and to estimate global emissions. HFC-365mfc and HFC-245fa first appeared in the atmosphere only ˜1 decade ago; they have grown rapidly to globally averaged dry air mole fractions of 0.53 ppt (in parts per trillion, 10-12) and 1.1 ppt, respectively, by the end of 2010. In contrast, HFC-227ea first appeared in the global atmosphere in the 1980s and has since grown to ˜0.58 ppt. We report the first measurements of HFC-236fa in the atmosphere. This long-lived compound was present in the atmosphere at only 0.074 ppt in 2010. All four substances exhibit yearly growth rates of >8% yr-1 at the end of 2010. We find rapidly increasing emissions for the foam-blowing compounds HFC-365mfc and HFC-245fa starting in ˜2002. After peaking in 2006 (HFC-365mfc: 3.2 kt yr-1, HFC-245fa: 6.5 kt yr-1), emissions began to decline. Our results for these two compounds suggest that recent estimates from long-term projections (to the late 21st century) have strongly overestimated emissions for the early years of the projections (˜2005-2010). Global HFC-227ea and HFC-236fa emissions have grown to average values of 2.4 kt yr-1 and 0.18 kt yr-1 over the 2008-2010 period, respectively.

Vollmer, Martin K.; Miller, Benjamin R.; Rigby, Matthew; Reimann, Stefan; Mühle, Jens; Krummel, Paul B.; O'Doherty, Simon; Kim, Jooil; Rhee, Tae Siek; Weiss, Ray F.; Fraser, Paul J.; Simmonds, Peter G.; Salameh, Peter K.; Harth, Christina M.; Wang, Ray H. J.; Steele, L. Paul; Young, Dickon; Lunder, Chris R.; Hermansen, Ove; Ivy, Diane; Arnold, Tim; Schmidbauer, Norbert; Kim, Kyung-Ryul; Greally, Brian R.; Hill, Matthias; Leist, Michael; Wenger, Angelina; Prinn, Ronald G.

2011-04-01

141

Measurements of gaseous PVTx properties and saturated vapor densities of refrigerant mixture R-125 + R-143a  

SciTech Connect

The experimental PVTx properties of a binary refrigerant mixture, R-125 (pentafluoroethane) + R-143a (1,1,1-trifluoroethane), have been measured for a composition of 50 mass% R-125 by a constant-mass method coupled with an expansion procedure in a range of temperatures from 305 to 400 K, pressures from 1.5 to 6.1 MPa, and densities from 92 to 300 kg {center_dot} m{sup {minus}3}. The experimental uncertainties of the present measurements are estimated to be within {+-} 7.2 mK in temperature, {+-} 3.0 ,Pa in pressure, {+-} 0.12 kg {center_dot} m{sup {minus}3} in density, and {+-} 0.040 mass% in composition. The sample purities are 99.953 mass% for R-125 and 99.998% for R-143a. Seven saturated vapor densities and dew point pressures of the R-125 + r-143a system were determined, on the basis of rather detailed PVTx properties measured in the vicinity of the saturation boundary as well as the thermodynamic behavior of isochores near saturation. The second and third virial coefficients for temperatures from 330 to 400 K were also determined.

Uchida, H.; Sato, H.; Watanabe, K. [Keio Univ., Yokohama (Japan). Dept. of System Design Engineering] [Keio Univ., Yokohama (Japan). Dept. of System Design Engineering

1999-01-01

142

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

NASA Astrophysics Data System (ADS)

HFC-23 (also known as CHF3, 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 of HCFC-22 (CHClF2, chlorodifluoromethane) production. HCFC-22, an ozone depleting substance (ODS), is used extensively in commercial refrigeration and air conditioning, in the extruded polystyrene (XPS) foam industries (dispersive applications) and also as a feedstock in fluoropolymer manufacture (a non-dispersive use). Aside from small markets in specialty uses, HFC-23 has historically been considered a waste gas that was, and often still is, simply vented to the atmosphere. Efforts have been made in the past two decades to reduce HFC-23 emissions, including destruction (incineration) in facilities in developing countries under the United Nations Framework Convention on Climate Change's (UNFCCC) Clean Development Mechanism (CDM), and by process optimization and/or voluntary incineration by most producers in developed countries. We present observations of lower-tropospheric mole fractions of HFC-23 measured by "Medusa" GC/MSD instruments from ambient air sampled in situ at the Advanced Global Atmospheric Gases Experiment (AGAGE) network of five remote sites and in Cape Grim air archive (CGAA) samples (1978-2009) from Tasmania, Australia. These observations are used with the AGAGE 2-D atmospheric 12-box model and an inverse method to produce model mole fractions and a "top-down" HFC-23 emission history. The model 2009 annual mean global lower-tropospheric background abundance is 22.8 (±0.2) pmol mol-1. The derived HFC-23 emissions show a "plateau" during 1997-2003, followed by a rapid ~50% increase to a peak of 15.0 (+1.3/-1.2) Gg/yr in 2006. Following this peak, emissions of HFC-23 declined rapidly to 8.6 (+0.9/-1.0) Gg/yr in 2009, the lowest annual emission of the past 15 years. We derive a 1990-2008 "bottom-up" HFC-23 emission history using data from the United Nations Environment Programme and the UNFCCC. Comparison with the top-down HFC-23 emission history shows agreement within the stated uncertainties. In the 1990s, HFC-23 emissions from developed countries dominated all other sources, then began to decline and eventually became fairly constant during 2003-2008. From the beginning of that plateau, the major factor determining the annual dynamics of global HFC-23 emissions became the historical rise of HCFC-22 production for dispersive uses in developing countries to a peak in 2007. Thereafter in 2007-2009, incineration through CDM projects became a larger factor, reducing global HFC-23 emissions despite rapidly rising HCFC-22 feedstock production in developing countries.

Miller, B. R.; Rigby, M.; Kuijpers, L. J. M.; Krummel, P. B.; Steele, L. P.; Leist, M.; Fraser, P. J.; McCulloch, A.; Harth, C.; Salameh, P.; Mühle, J.; Weiss, R. F.; Prinn, R. G.; Wang, R. H. J.; O'Doherty, S.; Greally, B. R.; Simmonds, P. G.

2010-05-01

143

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

NASA Astrophysics Data System (ADS)

HFC-23 (also known as CHF3, 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 of HCFC-22 (CHClF2, chlorodifluoromethane) production. HCFC-22, an ozone depleting substance (ODS), is used extensively in commercial refrigeration and air conditioning, in the extruded polystyrene (XPS) foam industries (dispersive applications) and also as a feedstock in fluoropolymer manufacture (a non-dispersive use). Aside from small markets in specialty uses, HFC-23 has historically been considered a waste gas that was, and often still is, simply vented to the atmosphere. Efforts have been made in the past two decades to reduce HFC-23 emissions, including destruction (incineration) in facilities in developing countries under the United Nations Framework Convention on Climate Change's (UNFCCC) Clean Development Mechanism (CDM), and by process optimization and/or voluntary incineration by most producers in developed countries. We present observations of lower-tropospheric mole fractions of HFC-23 measured by "Medusa" GC/MSD instruments from ambient air sampled in situ at the Advanced Global Atmospheric Gases Experiment (AGAGE) network of five remote sites (2007-2009) and in Cape Grim air archive (CGAA) samples (1978-2009) from Tasmania, Australia. These observations are used with the AGAGE 2-D atmospheric 12-box model and an inverse method to produce model mole fractions and a "top-down" HFC-23 emission history. The model 2009 annual mean global lower-tropospheric background abundance is 22.6 (±0.2) pmol mol-1. The derived HFC-23 emissions show a "plateau" during 1997-2003, followed by a rapid ~50% increase to a peak of 15.0 (+1.3/-1.2) Gg/yr in 2006. Following this peak, emissions of HFC-23 declined rapidly to 8.6 (+0.9/-1.0) Gg/yr in 2009, the lowest annual emission of the past 15 years. We derive a 1990-2008 "bottom-up" HFC-23 emission history using data from the United Nations Environment Programme and the UNFCCC. Comparison with the top-down HFC-23 emission history shows agreement within the stated uncertainties. In the 1990s, HFC-23 emissions from developed countries dominated all other sources, then began to decline and eventually became fairly constant during 2003-2008. By this point, with developed countries' emissions essentially at a plateau, the major factor controlling the annual dynamics of global HFC-23 emissions became the historical rise of developing countries' HCFC-22 dispersive use production, which peaked in 2007. Thereafter in 2007-2009, incineration through CDM projects became a larger factor, reducing global HFC-23 emissions despite rapidly rising HCFC-22 feedstock production in developing countries.

Miller, B. R.; Rigby, M.; Kuijpers, L. J. M.; Krummel, P. B.; Steele, L. P.; Leist, M.; Fraser, P. J.; McCulloch, A.; Harth, C.; Salameh, P.; Mühle, J.; Weiss, R. F.; Prinn, R. G.; Wang, R. H. J.; O'Doherty, S.; Greally, B. R.; Simmonds, P. G.

2010-08-01

144

Applications of the Simple Multi-Fluid Model to Correlations of the Vapor-Liquid Equilibrium of Refrigerant Mixtures Containing Carbon Dioxide  

NASA Astrophysics Data System (ADS)

This study presents a simple multi-fluid model for Helmholtz energy equations of state. The model contains only three parameters, whereas rigorous multi-fluid models developed for several industrially important mixtures usually have more than 10 parameters and coefficients. Therefore, the model can be applied to mixtures where experimental data is limited. Vapor-liquid equilibrium (VLE) of the following seven mixtures have been successfully correlated with the model: CO2 + difluoromethane (R-32), CO2 + trifluoromethane (R-23), CO2 + fluoromethane (R-41), CO2 + 1,1,1,2- tetrafluoroethane (R-134a), CO2 + pentafluoroethane (R-125), CO2 + 1,1-difluoroethane (R-152a), and CO2 + dimethyl ether (DME). The best currently available equations of state for the pure refrigerants were used for the correlations. For all mixtures, average deviations in calculated bubble-point pressures from experimental values are within 2%. The simple multi-fluid model will be helpful for design and simulations of heat pumps and refrigeration systems using the mixtures as working fluid.

Akasaka, Ryo

145

First Observations of the Fourth Generation Synthetic Halocarbons HFC-1234yf, HFC-1234ze(E), and HCFC-1233zd(E) in the Atmosphere.  

PubMed

Halogenated alkenes are a class of anthropogenic substances, which replace ozone-depleting substances and long-lived greenhouse gases in the foam-blowing, refrigeration, and solvent sectors. We report the first multiyear atmospheric measurements of the hydrofluorocarbons HFC-1234yf (2,3,3,3-tetrafluoroprop-1-ene, CF3CF?CH2), and HFC-1234ze(E) (E-1,3,3,3-tetrafluoroprop-1-ene trans-CF3CH?CHF), and the hydrochlorofluorocarbon HCFC-1233zd(E) (E-1-chloro-3,3,3-trifluoroprop-1-ene trans-CF3CH?CHCl) from the high altitude observatory at Jungfraujoch and from urban Dubendorf (Switzerland). When observations started in 2011 HFC-1234yf was undetectable at Jungfraujoch (mole fractions <0.003 ppt, parts-per-trillion, 10(-12)) but since then the percentage of measurements with detectable mole fractions has steadily increased to 4.5% in 2014. By contrast, in 2014 HFC-1234ze(E) was detectable in half of our samples at Jungfraujoch and in all samples at Dubendorf demonstrating the wide use of this compound within the air mass footprints of the stations. Our back trajectory analysis for the Jungfraujoch observations suggests high emission strength of HFC-1234ze(E) in the Belgium/Netherlands region. HCFC-1233zd(E) is present at very low mole fractions (typically <0.03 ppt) at both stations, and features pronounced seasonality and a general absence of pollution events during our 2013-2014 measurements. This is indicative of the presence of significant emissions from source locations outside the footprints of the two stations. Based on a simple one-box model calculation we estimate globally increasing HCFC-1233zd(E) emissions from 0.2 Gg yr(-1) in 2013 to 0.5 Gg yr(-1) for 2014. PMID:25625175

Vollmer, Martin K; Reimann, Stefan; Hill, Matthias; Brunner, Dominik

2015-03-01

146

Surface tension of pentafluoroethane (HFC125)  

Microsoft Academic Search

A set of accurate surface-tension data for HFC-125 has been obtained experimentally with both an absolute capillary rise technique and a differential capillary rise technique in the temperature range of 233.15–333.15 K. The purity of the experimental HFC-125 sample is 99.98 wt%. The two sets of experimental results with an absolute capillary rise method agree well with each other and,

M. F. Liu; L. Z. Han; M. S. Zhu

1994-01-01

147

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

NASA Astrophysics Data System (ADS)

By means of the transient and steady-state coaxial cylinder methods, the thermal conductivity of pentafluoroethane 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-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.; Asambaev, A. J.; Zausaev, I. A.

1995-09-01

148

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

149

Thermal conductivity and PVT measurements of pentafluoroethane (refrigerant HFC125)  

Microsoft Academic Search

By means of the transient and steady-state coaxial cylinder methods, the thermal conductivity of pentafluoroethane 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

O. B. Tsvetkov; A. V. Kletski; Yu. A. Laptev; A. J. Asambaev; I. A. Zausaev

1995-01-01

150

Thermal conductivity and PVT measurements of pentafluoroethane (refrigerant HFC125)  

Microsoft Academic Search

By means of the transient and steady-state coaxial cylinder methods, the thermal conductivity of pentafluoroethane 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

O. B. Tsvetkov; A. V. Kletski; Yu. A. Laptev; A. J. Asambaev; I. A. Zausaev

1995-01-01

151

Enhancing the performance of evaporative spray cooling in air cycle refrigeration and air conditioning technology  

Microsoft Academic Search

The phase out of CFC refrigerants and the concern over their proposed replacements, HFC, has led to a reassessment of many natural refrigeration technologies including air cycle. It is recognised that to fulfil the full potential of air cycle technology, improvements in system energy consumption must be made. One area where it is believed that significant energy savings can be

S. Hamlin; R. Hunt; S. A. Tassou

1998-01-01

152

The effect of blowing agent choice on energy use and global warming impact of a refrigerator  

Microsoft Academic Search

A study, comparing the effect of blowing agent selection on energy consumption and the life cycle climate performance (LCCP) of a typical European refrigerator is discussed. Energy consumption of prototype European-style refrigerators made with a foam formulation with HFC-245fa as the blowing agent was measured and compared with energy consumption of the same model as currently produced (using a foam

Robert W. Johnson

2004-01-01

153

Viscosity of Alternative Refrigerants R407C and R407E in the Vapor Phase from 298.15 to 423.15 K  

NASA Astrophysics Data System (ADS)

This paper presents new measurements of the viscosity of gaseous R407C (23 mass% HFC-32, 25 mass% HFC-125, 52 mass% HFC-143a) and R407E (25 mass% HFC-32, 15 mass% HFC-125, 60 mass% HFC-143a). The measurements were carried out with an oscillating-disk viscometer of the Maxwell type at temperatures from 298.15 to 423.15 K. The densities of these two fluid mixtures were calculated with the equation-of-state model in REFPROP. The viscosity at normal pressures was analyzed with the extended law of corresponding states developed by Kestin et al., and the scaling parameters needed in the analysis were obtained from our previous studies for the viscosity of the binary mixtures consisting of HFC-32, HFC-125, and HFC-134a. The modified Enskog theory developed by Vesovic and Wakeham (V-W method) was applied to predict the viscosity for the ternary gaseous HFC mixtures under pressure. As for the calculation of pseudo-radial distribution functions in mixtures, a method based on the equation of state for hard-sphere fluid mixtures proposed by Carnahan-Starling was applied. It was found that the V-W method can predict the viscosity of R407C and R407E without any additional parameters for the ternary mixture.

Yokoyama, C.; Takahashi, M.; Tomida, D.

2006-05-01

154

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

155

Potentially acceptable substitutes for the chlorofluorocarbons: properties and performance features of HFC134a, HCFC123, and HCFC141b  

Microsoft Academic Search

Potentially acceptable substitutes are known for CFC-11 and CFC-12-the most important Chlorofluorocarbons. HFC-134a could replace CFC-12 in airconditioning and refrigeration and both HCFC-123 and HCFC-141b show promise as CFC-11 substitutes. The replacement molecules all have significantly reduced greenhouse and ozone depletion potentials compared to their fully halogenated counterparts. HCFC-123 is theoretically a less efficient blowing agent than CFC-11, but 141b

B. Sukornick

1989-01-01

156

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

157

Global warming impacts of ozone-safe refrigerants and refrigeration, heating, and air-conditioning technologies  

SciTech Connect

International agreements mandate the phase-out of many chlorine containing compounds that are used as the working fluid in refrigeration, air-conditioning, and heating equipment. Many of the chemical compounds that have been proposed, and are being used in place of the class of refrigerants eliminated by the Montreal Protocol are now being questioned because of their possible contributions to global warming. Natural refrigerants are put forth as inherently superior to manufactured refrigerants because they have very low or zero global warming potentials (GWPs). Questions are being raised about whether or not these manufactured refrigerants, primarily hydrofluorocarbons (HFCs), should be regulated and perhaps phased out in much the same manner as CFCs and HCFCs. Several of the major applications of refrigerants are examined in this paper and the results of an analysis of their contributions to greenhouse warming are presented. Supermarket refrigeration is shown to be an application where alternative technologies have the potential to reduce emissions of greenhouse gases (GHG) significantly with no clear advantage to either natural or HFC refrigerants. Mixed results are presented for automobile air conditioners with opportunities to reduce GHG emissions dependent on climate and comfort criteria. GHG emissions for hermetic and factory built systems (i.e. household refrigerators/freezers, unitary equipment, chillers) are shown to be dominated by energy use with much greater potential for reduction through efficiency improvements than by selection of refrigerant. The results for refrigerators also illustrate that hydrocarbon and carbon dioxide blown foam insulation have lower overall effects on GHG emissions than HFC blown foams at the cost of increased energy use.

Fischer, S.; Sand, J.; Baxter, V.

1997-12-01

158

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

159

Two-phase frictional pressure drop of R-134a and R-410A refrigerant-oil mixtures in straight tubes and U-type wavy tubes  

SciTech Connect

This study presents single-phase and two-phase pressure drop data for R-134a/oil mixture flowing in a wavy tube with inner diameter of D=5.07mm and curvature ratio 2R/D=5.18 and R-410A/oil mixture flowing in a wavy tube of D=3.25mm and 2R/D=3.91. Both mixtures have oil concentration C=0%, 1%, 3% and 5% for the tests. The ratio of frictional factor between U-bend in wavy tube and straight tube (f{sub C}/f{sub S}) is about 3.5 for Re<2500 and is approximate 2.5 for Re=3500-25,000 for oil and liquid R-134a mixture flowing in the 5.07mm diameter wavy tube. The influence of oil concentration on single-phase friction factor is negligible, provided that the properties are based on the mixture of lubricant and refrigerant. The ratio between two-phase pressure gradients of U-bend and straight tube is about 2.5-3.5. This ratio is increased with oil concentration and vapor quality. The influence of oil is augmented at a higher mass flux for liquid spreading around the periphery at an annular flow pattern. Moreover, the influence of lubricant becomes more evident of a U-bend configuration. This is associated the induced swirled flow motion and an early change of flow pattern from stratified to annular flow pattern. The frictional two-phase multiplier for straight tube can be fairly correlated by using the Chisholm correlation for the data having Martinelli parameter X between 0.05 and 1.0. Fridel correlation also shows a good agreement with a mean deviation of 17.6% to all the straight tube data. For the two-phase pressure drop in U-bend, the revised Geary correlation agrees very well with the R-134a and R-410A oil-refrigerant data with a mean deviation of 16.4%. (author)

Chen, Ing Youn; Wu, Yu-Shi [Mechanical Engineering Department, National Yunlin University of Science and Technology, Yunlin 640 (Taiwan); Chang, Yu-Juei; Wang, Chi-Chuan [Energy and Resource Laboratories, Industrial Technology Research Institute Hsinchu 310 (Taiwan)

2007-02-15

160

Refrigeration and thermometry of liquid {sup 3}He-{sup 4}He mixtures in the ballistic regime  

SciTech Connect

The ballistic regime of liquid {sup 3}He-{sup 4}He mixtures is characterized by a large mean free path {lambda} of the thermal excitations compared to the characteristic dimension of the experiment. We report on investigations of the transport properties of mixtures as well as superfluid {sup 3}He in the ballistic regime by means of the vibrating wire technique. In order to avoid possible sources of heat leaks into the liquid, the experimental setup was built as far as possible of pure materials only. The contribution of a Ag sinter to the heat leak as well as its influence on the attainable minimum temperature of the mixtures were investigated by performing measurements in two similar setups which differed in the size of the heat exchanger by about one order of magnitude. Moreover, we have used the vibrating wire partly immersed in the superfluid {sup 3}He-B phase of a phase-separated mixture as a very sensitive, continuously monitoring thermometer for liquid mixtures in their ballistic regime. The achieved minimum temperature of a 6.8%-mixture at p = 0.35 bar and of a 9.5%-mixture at p = 9.8 bar was 130 {mu}K. This value can be considered as an upper limit for the temperature of the mixtures as the damping of the vibrating wire thermometer saturates at this temperature due to its intrinsic properties.

Koenig, R.; Betat, A.; Pobell, F. [Universitaet Bayreuth (Germany)

1994-11-01

161

Potentially acceptable substitutes for the chlorofluorocarbons: Properties and performance features of HFC-134a, HCFC-123, and HCFC-141b  

SciTech Connect

Potentially acceptable substitutes are known for CFC-11 and CFC-12 - the most important chlorofluorocarbons. HFC-134a could replace CFC-12 in air-conditioning and refrigeration and both HCFC-123 and HCFC-141b show promise as CFC-11 substitutes. The replacement molecules all have significantly reduced greenhouse and ozone depletion potentials compared to their fully halogenated counterparts. HCFC-123 is theoretically a less efficient blowing agent than CFC-11, but 141b is more efficient. Results from experimental foaming tests confirm these relationships and show that initial insulating values are slightly lower for 141 b and 123 than 11. Both substitutes are nonflammable liquids. Based on its physical properties, HFC-134a is an excellent replacement candidate for CFC-12. In addition, it is more thermally stable than CFC-12. A new family of HFC-134a compatible lubricant oils will be required. The estimated coefficient of performance (COP) of 134a is 96-98% that of CFC-12. Subacute toxicity tests show HFC-134a to have a low order of toxicity. HCFC-123 reveals no serious side effects at a concentration of 0.1% in subchronic tests and the inhalation toxicity of 141b is lower than that of CFC-11 based on a 6-h exposure. Chronic tests on all the new candidates will have to be completed for large-scale commercial use. Allied-Signal is conducting process development at a highly accelerated pace, and they plan to begin commercialization of substitutes within 5 years.

Sukornick, B. (Allied-Signal Inc., Buffalo, NY (USA))

1989-05-01

162

Overview of CFC replacement issues for household refrigeration  

NASA Astrophysics Data System (ADS)

In 1974, the famous ozone depletion theory of Rowland and Molina claimed that chlorofluorocarbons (CFCs) diffuse into the stratosphere where they are broken down by photolysis to release chlorine atoms that catalytically destroy ozone. Although the understanding of the science is still imperfect, there is little doubt that CFCs play a major role in the Antarctic ozone hole phenomenon and the decline in ozone observed in the rest of the world. Another issue that has become increasingly important is the potential of CFCs to change the earth's temperature and to modify the climate. While the main impact in global warming is made by increased concentrations of carbon dioxide, CFCs and other trace gases also contribute to this effect. In an effort to respond to the global environmental threat, a CFC protocol was adopted during a diplomatic conference in Montreal. This document, known as the Montreal Protocol, was ratified in 1988 and put into effect on January 1, 1989. In accordance with Article 6 of the Montreal Protocol, the countries that signed the agreement shall periodically assess the control measures provided for in the Protocol. As part of that assessment process, household refrigeration was investigated to determine the status of CFC-12 replacements. The conclusion was that much progress has been made towards finding a suitable replacement. Compressors designed for HFC-134a have efficiencies comparable to those for CFC-12 and acceptable reliability tests have been obtained with ester lubricants. In addition, other replacements such as R-152a and refrigerant mixtures exist, but will require more study. Cycle options, such as the Stirling cycle, may be viable, but are further out in the future. The impact of new refrigerants is expected to result in elimination of CFC-12 consumption in developed countries by 1997 and in developing countries by 2005.

Vineyard, E. A.; Roke, L.; Hallett, F.

163

Overview of CFC replacement issues for household refrigeration  

SciTech Connect

In 1974, the famous ozone depletion theory of Rowland and Molina claimed that chlorofluorocarbons (CFCs) diffuse into the stratosphere where they are broken down by photolysis to release chlorine atoms that catalytically destroy ozone. Although the understanding of the science is still imperfect, there is little doubt that CFCs play a major role in the Antarctic ozone hole phenomenon and the decline in ozone observed in the rest of the world. Another issue that has become increasingly important is the potential of CFCs to change the earth`s temperature and to modify the climate. While the main impact in global warming is made by increased concentrations of carbon dioxide, CFCs and other trace gases also contribute to this effect. In an effort to respond to the global environmental threat, a CFC protocol was adopted during a diplomatic conference in Montreal. This document, known as the Montreal Protocol, was ratified in 1988 and put into effect on January 1, 1989. In accordance with Article 6 of the Montreal Protocol, the countries that signed the agreement shall periodically assess the control measures provided for in the Protocol. As part of that assessment process, household refrigeration was investigated to determine the status of CFC-12 replacements. The conclusion was that much progress has been made towards finding a suitable replacement. Compressors designed for HFC-134a have efficiencies comparable to those for CFC-12 and acceptable reliability tests have been obtained with ester lubricants. In addition, other replacements such as R-152a and refrigerant mixtures exist, but will require more study. Cycle options, such as the Stirling cycle, may be viable, but are further out in the future. The impact of new refrigerants is expected to result in elimination of CFC-12 consumption in developed countries by 1997 and in developing countries by 2005.

Vineyard, E.A. [Oak Ridge National Lab., TN (United States); Roke, L. [Fisher and Paykel, Auckland (New Zealand); Hallett, F. [Frigidaire, Washington, DC (United States)

1991-12-31

164

Overview of CFC replacement issues for household refrigeration  

SciTech Connect

In 1974, the famous ozone depletion theory of Rowland and Molina claimed that chlorofluorocarbons (CFCs) diffuse into the stratosphere where they are broken down by photolysis to release chlorine atoms that catalytically destroy ozone. Although the understanding of the science is still imperfect, there is little doubt that CFCs play a major role in the Antarctic ozone hole phenomenon and the decline in ozone observed in the rest of the world. Another issue that has become increasingly important is the potential of CFCs to change the earth's temperature and to modify the climate. While the main impact in global warming is made by increased concentrations of carbon dioxide, CFCs and other trace gases also contribute to this effect. In an effort to respond to the global environmental threat, a CFC protocol was adopted during a diplomatic conference in Montreal. This document, known as the Montreal Protocol, was ratified in 1988 and put into effect on January 1, 1989. In accordance with Article 6 of the Montreal Protocol, the countries that signed the agreement shall periodically assess the control measures provided for in the Protocol. As part of that assessment process, household refrigeration was investigated to determine the status of CFC-12 replacements. The conclusion was that much progress has been made towards finding a suitable replacement. Compressors designed for HFC-134a have efficiencies comparable to those for CFC-12 and acceptable reliability tests have been obtained with ester lubricants. In addition, other replacements such as R-152a and refrigerant mixtures exist, but will require more study. Cycle options, such as the Stirling cycle, may be viable, but are further out in the future. The impact of new refrigerants is expected to result in elimination of CFC-12 consumption in developed countries by 1997 and in developing countries by 2005.

Vineyard, E.A. (Oak Ridge National Lab., TN (United States)); Roke, L. (Fisher and Paykel, Auckland (New Zealand)); Hallett, F. (Frigidaire, Washington, DC (United States))

1991-01-01

165

Surface tension of pentafluoroethane (HFC-125)  

NASA Astrophysics Data System (ADS)

A set of accurate surface-tension data for HFC-125 has been obtained experimentally with both an absolute capillary rise technique and a differential capillary rise technique in the temperature range of 233.15 333.15 K. The purity of the experimental HFC-125 sample is 99.98 wt%. The two sets of experimental results with an absolute capillary rise method agree well with each other and, also, with the experimental results with a differential capillary rise method. The absolute deviations of experimental results with these two methods are within 0.01 mN · m-1. The relative deviation are within 0.2%. A van der Waals surface-tension correlation is also proposed.

Liu, M. F.; Han, L. Z.; Zhu, M. S.

1994-09-01

166

Dielectric Properties of Liquid Pentafluoroethane (HFC125)  

Microsoft Academic Search

This paper reports measurements of the static relative permittivity of HFC-125 in the liquid phase, performed by using the direct capacitance method at 10 kHz, for temperatures from 214 to 304 K and pressures up to 16 MPa. The repeatability of the measurements was found to be of the order of ±0.7×10-3and the uncertainty is estimated to be better than

L. M. Pereira; F. E. de Brito; A. N. Gurova; U. V. Mardolcar; C. A. Nieto de Castro

2001-01-01

167

Ultra High Pressure Tribometer for Testing CO2 Refrigerant at Chamber Pressures up to 2000 psi to Simulate Compressor Conditions  

Microsoft Academic Search

The growing interest for using the natural refrigerant carbon dioxide (CO2) in refrigeration and air-conditioning applications instead of HFC refrigerants, due to environmental concerns, has led to the development of an ultra high pressure tribometer (UHPT) specifically tailored for testing in CO2 environment. The existing research on tribology related to CO2 environment has focused on investigations at relatively low chamber

NICHOLAOS G. DEMAS; ANDREAS A. POLYCARPOU

2006-01-01

168

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

169

Alternative refrigerants and refrigeration cycles for domestic refrigerators  

NASA Astrophysics Data System (ADS)

This project initially focused on using nonazeotropic refrigerant mixtures (NARM's) 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 NARM's 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 NARM's 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

170

1. INTRODUCTION As a result of the phas e-out of CFC and HCFC refrigerants  

E-print Network

1 1. INTRODUCTION As a result of the phas e-out of CFC and HCFC refrigerants in heat pump, refrigeration and air-conditioning systems, the binary and ternary refrigerant mixtures have received attention for several mixtures. In this study, additional experimental data for refrigerant mixtures from different

Kandlikar, Satish

171

Physical properties of fluorinated propane and butane derivatives as alternative refrigerants  

NASA Astrophysics Data System (ADS)

The paper presents physical property measurements for 24 fluorinated propane and butane derivatives and one fluorinated ether which include melting point, boiling point, vapor pressure below the boiling point, heat of vaporization at the boiling point, critical properties (temperature and density), and liquid-phase heat capacities at 40 C. Measured vapor pressures are reported to the critical temperature for four of the compounds: HFC-227ea, HFC-245cb, HFC-236ea, and HFE-125a. These measured data, combined with estimated vapor-phase densities, heat capacities, and vapor pressures, may be used to evaluate the potentials of these chemicals as alternative refrigerants. Modified corresponding states methods, using HFC-134a as a reference fluid, are presented as a way to obtain the needed estimated data, and the accuracy of these methods is judged by comparisons with measured data.

Beyerlein, A.; Desmarteau, D.; Hwang, S.; Smith, N.; Joyner, P.

172

HFC-134a conversion of large tonnage, multi-stage centrifugal chillers: Lessons learned  

SciTech Connect

On December 31, 1995, worldwide production of CFC refrigerants will come to a complete and permanent stop. Trigen-Nassau has effected a comprehensive CFC program, including refrigerant containment and the first refrigerant conversion in a plant of this type. Trigen-Nassau initiated its containment program prior to July 1, 1992, the effective date of the no venting law. The course of action included scheduled leak checking of all machines and prompt repair of leaks. Centrifugal Services, an independent service contractor performed these repairs. In 1994, Trigen contacted Centrifugal to perform a refrigerant conversion on a multi-stage, centrifugal chiller, with a nominal capacity of 2500 tons at the Central Utilities Plant. The machine is a York OM open drive, steam turbine driven machine, designed for R-500. The machine is now running with HFC-134a (Dupont Suva MP-Cold). This successful conversion was performed without modification to the steam turbine or the compressor impeller. The conversion is now complete, and the machine has been reliably producing 2450 tons of chilling.

Orsetti, M.V. [Trigen-Nassau Energy Corp., Garden City, NY (United States); Tangel, T.E. [Centrifugal Services Inc., New York, NY (United States)

1995-12-31

173

Evaporation heat transfer and pressure drop of HFC134a in a helically coiled concentric tube-in-tube heat exchanger  

Microsoft Academic Search

The two-phase heat transfer coefficient and pressure drop of HFC-134a during evaporation inside a smooth helically coiled concentric tube-in-tube heat exchanger are experimentally investigated. The test section is a 5.786-m long helically coiled tube with refrigerant flowing in the inner tube and heating water flowing in the annulus. The inner tube is made from copper tubing of 9.52mm outer diameter

Somchai Wongwises; Maitree Polsongkram

2006-01-01

174

Condensation heat transfer and pressure drop of HFC134a in a helically coiled concentric tube-in-tube heat exchanger  

Microsoft Academic Search

The two-phase heat transfer coefficient and pressure drop of pure HFC-134a condensing inside a smooth helically coiled concentric tube-in-tube heat exchanger are experimentally investigated. The test section is a 5.786m long helically coiled double tube with refrigerant flowing in the inner tube and cooling water flowing in the annulus. The inner tube is made from smooth copper tubing of 9.52mm

Somchai Wongwises; Maitree Polsongkram

2006-01-01

175

Wear and Galling of 356-T6 Aluminum-on-Steel in Low Amplitude Reciprocating Sliding in the Presence of Synthetic Lubricants in HFC134a Atmosphere  

Microsoft Academic Search

The wear and galling of 356-T6 aluminum against steel in low amplitude reciprocating motion (5° oscillation) has been studied in a block-on-ring wear test machine. The lest utilized stepwise increasing loads (9-454 kg range) lubricants in CFC-12 or HFC-134a refrigerant atmospheres. For three lubricants utilized [a mineral oil (M100), a polyalkylene glycol (U8), and an esterified polypropylene oxide glycol (D1)

Spyros I. Tseregounis

1996-01-01

176

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

177

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

E-print Network

-20% of world energy use is linked to the food chain Refrigeration plays an important role in the cycleRefrigerationRefrigerationRefrigeration coursecourse # 424503.0# 424503.0 v.v. 20122012 6. Food cooling and freezingg f g Ron Zevenhoven Ã?Ã?bo Akademi Refigeration / Kylteknik 6 1 Th l ti f f d6.1 Thermal properties of foods 7.11.2012Ã?bo Akademi Univ - Thermal

Zevenhoven, Ron

178

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

SciTech Connect

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 boiling of sat. aq. CaSO{sub 4} solution show that effects of fouling (wall superheat changes, deposit weight) are more pronounced at 80 kW/m{sup 2} than at 10 kW/m{sup 2} heat flux; precipitation fouling show an effect within the first 2 h exposure. High flux surfaces have lower deposition weight than other surfaces; thus the deposition rate may depend strongly on wall superheat. The numerous nucleation sites of the enhanced surfaces provide more turbulent motion near the boiling surface than for the plain surface; thus the removal rate should be greater for an enhanced surface, although no removal of a deposit was ever observed.

Curcio, L.A.; Somerscales, E.F.

1994-08-01

179

Experimental evaluation of automotive air-conditioning using HFC-134a and HC-134a  

NASA Astrophysics Data System (ADS)

An experimental study to evaluate the energy consumption of an automotive air conditioning is presented. In this study, these refrigerants will be tested using the experimental rig which simulated the actual cars as a cabin complete with a cooling system component of the actual car that is as the blower, evaporator, condenser, radiators, electric motor, which acts as a vehicle engine, and then the electric motor will operate the compressor using a belt and pulley system, as well as to the alternator will recharge the battery. The compressor working with the fluids HFC-134a and HC-134a and has been tested varying the speed in the range 1000, 1500, 2000 and 2500 rpm. The measurements taken during the one hour experimental periods at 2-minutes interval times for temperature setpoint of 20°C with internal heat loads 0, 500, 700 and 1000 W. The final results of this study show an overall better energy consumption of the HFC-134a compared with the HC-134a.

Nasution, Henry; Zainudin, Muhammad Amir; Aziz, Azhar Abdul; Latiff, Zulkarnain Abdul; Perang, Mohd Rozi Mohd; Rahman, Abd Halim Abdul

2012-06-01

180

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

181

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

182

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.

183

CFC prices rise above dropping HFC prices, spread should widen  

SciTech Connect

Chlorofluorocarbon (CFC) replacement hydrofluorocarbon (HFC)-134a has gained an economic edge over CFC-12 in the U.S. says ICI Americas Chemicals & Plastics president Robin Gadsby. Although conversion costs are keeping many customers from making the switch. Gadsby says demand for HFC-134a should exceed global capacity in the mid-1990s. He adds that ICI can recoup its $430-million investment in HFCs.

Kirschner, E.

1993-12-15

184

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

185

Oil-return characteristics of refrigerant oils in split heat pump system  

SciTech Connect

Currently, HFC substitute refrigerants for R-22 are being evaluated in air-conditioning and heat pump applications. The oil return characteristics and heat transfer effects of the lubricants are being studied again. Based on commercial refrigeration experience POEs are the lubricants of choice for HFC refrigerants. POEs have two major drawbacks: hygroscopicity and high cost. Thus the question is raised to what extent is it possible to replace POEs with a lower cost, but immiscible, oil such as mineral oil. It is the purpose of this study to experimentally investigate the oil return behavior of R-407C with mineral oil in a split three-ton heat pump in comparison to R407C/POE and R-22/Mineral Oil.

Sundaresan, S.G. [Copeland Corp., Sidney, OH (United States). Materials Engineering and Systems Chemistry; Radermacher, R.

1996-08-01

186

Accelerated screening methods for determining chemical and thermal stability of refrigerant-lubricant mixtures: Part 2, Experimental comparison and verification of methods. Quarterly technical progress report, 1 March 1993--30 June 1993  

SciTech Connect

Initial research focused on conductivity measurements to perform in heated situ degradation measurements of CFC-12/mineral oil and HCFC-22/mineral oil mixtures at 175C in sealed glass tubes. Tungsten rods were sealed into round bottoms of the sealed tubes to provide electrical connections for in situ conductivity measurements. Steel, Cu and W were used as catalysts as well as conductivity probes. Conductivity measurements have been made with both ac and dc voltage inputs. Preliminary results indicate that in situ conductivity measurements correlate with refrigerant/lubricant degradation as determined by other analytical techniques (color, gas chromatography). Some of the continuous conductivity measurement tests appear to accelerate as well as monitor the refrigerant/lubricant degradation. W posts with a valve steel catalyst appear optimum combination for conductivity measurements. Ferric fluoride catalysts and differential thermal analysis were also investigated. Initial tests indicate that the ferric fluoride catalyst has potential for testing lubricant stability at temperatures lower than 175C . Differential thermal analysis have minimal potential for in situ measurements of long-term refrigerant/lubricant degradation processes.

Kauffman, R.

1993-10-01

187

The development of a proff of principle superfluid Joule-Thomson refrigerator for cooling below 1 Kelvin  

E-print Network

A new type of sub-Kelvin refrigerator, the superfluid Joule-Thomson refrigerator, has been developed and its performance has been experimentally verified. This refrigerator uses a liquid superfluid mixture of He and 4He ...

Miller, Franklin K., 1970-

2005-01-01

188

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

189

Aging of polyurethane foam insulation in simulated refrigerator walls  

SciTech Connect

Laboratory data are presented on the thermal conductivity of polyurethane foam insulation in composite test panels that simulate refrigerator walls. The test panels consisted of a steel skin, an ABS plastic liner, and a polyurethane foam core. Foam cores were produced with three different blowing agents (CFC-11, HCFC-141b, and a HCFC-142/22 blend). Periodic thermal measurements have been made on these panels over a three and one half year period in an effort to detect aging processes. Data obtained on foam encased in the panels were compared with measurements on thin foam slices that were removed from similar panels. The data show that the encapsulation of the foam in the solid boundary materials greatly reduces the aging rate. The plan is presented for a follow-on project that is being conducted on the aging of foams blown with HCFC-141b, HFC-134a, HFC-245fa, and cyclopentane.

Wilkes, K.E.; Yarbrough, D.W.; Weaver, F.J.

1997-10-01

190

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

191

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

192

Alternatives to ozone depleting refrigerants in test equipment  

NASA Technical Reports Server (NTRS)

This paper describes the initial results of a refrigerant retrofit project at the Aerospace Guidance and Metrology Center (AGMC) at Newark Air Force Base, Ohio. The objective is to convert selected types of test equipment to properly operate on hydrofluorocarbon (HFC) alternative refrigerants, having no ozone depleting potential, without compromising system reliability or durability. This paper discusses the primary technical issues and summarizes the test results for 17 different types of test equipment: ten environmental chambers, two ultralow temperature freezers, two coolant recirculators, one temperature control unit, one vapor degreaser, and one refrigerant recovery system. The postconversion performance test results have been very encouraging: system capacity and input power remained virtually unchanged. In some cases, the minimum operating temperature increased by a few degrees as a result of the conversion, but never beyond AGMC's functional requirements.

Hall, Richard L.; Johnson, Madeleine R.

1995-01-01

193

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

194

Viscosity of gaseous HFC-125 (pentafluoroethane) under high pressures  

SciTech Connect

This paper reports experimental results for the viscosity of gaseous HFC-125 (pentafluoroethane) under high pressures. The measurements were carried out with an oscillating-disk viscometer of the Maxwell type at temperatures from 298.15 to 423.15 K and at pressures up to the saturated vapor pressures at each temperature at subcritical conditions or up to 9 MPa at supercritical temperatures. Intermolecular scaling parameters of HFC-125 for the extended corresponding states were determined from the viscosity data at 0.1 MPa. An empirical viscosity equation is proposed to interpolate the present experimental results as a function of temperature and density.

Takahashi, M.; Shibasaki-Kitakawa, N.; Yokoyama, C. [Tohoku Univ., Sendai (Japan). Inst. for Chemical Reaction Science] [Tohoku Univ., Sendai (Japan). Inst. for Chemical Reaction Science

1999-03-01

195

Refrigeration Showcases  

NASA Technical Reports Server (NTRS)

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

1997-01-01

196

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

197

6th IIR Gustav Lorentzen Natural Working Fluids Conference Refrigerating concept for small supermarkets using multiple modular cascade systems with carbon dioxide and propylene  

Microsoft Academic Search

This paper presents a project that has been partly funded by the Danish Environmental Protection Agency (Heerup, 2004) in order to increase the number of available technical solutions as an alternative to fulfilling the requirements of Statutory Order no. 552 of 2 July 2002 Regulating Certain Industrial Greenhouse Gases, which implies limiting the size of HFC refrigerant charges to a

Christian Heerup

198

HFC -Hosaeus Fitness Center Romney -Romney Dance Studio  

E-print Network

$30 Wall Rock Climbing Tennis Clinics (5-weeks) Ongoing Enrollment TBD TBD $40 HFC Ski Conditioning Arts Relaxation Techniques Oct 8, 15 & 22 Tuesdays 12:10-1 pm $25 RSF Mind & Body Intro to Rock Climbing Sep 17 - Oct 10 T/Th 2-3 pm $30 Wall Bouldering Training & Technique Oct 22 - Nov 14 T/Th 2-3 pm

Maxwell, Bruce D.

199

The Hierarchical Fair Competition (HFC) Model for Parallel Evolutionary Algorithms  

E-print Network

fitness tend to survive. New "explorer" individuals in fairly different regions of the search space computation is inspired by the stratified competition often seen in society and biology. Subpopulations, but not of a higher one. HFC's balanced exploration and exploitation, while avoiding premature convergence, is shown

Hu, Jianjun

200

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

E-print Network

(v-c), (2) absorption, (3) gas expansionp p ( ), ( ) p , ( ) g p and (4) thermo-electric (T The energy input occurs at the point where the pressure of the refrigerant gas is increased Pictures: S90 6-compression Absorption Absorption + heat exchange Process comparison /2Process comparison /2 In the compressor, work

Zevenhoven, Ron

201

Cryogenic refrigerator  

Microsoft Academic Search

This patent describes a modified Stirling cycle cryogenic refrigerator. It has a first piston for compressing a working gas in a first cylinder, a second piston for expanding such working gas in a second cylinder, channel means connecting the first and second cylinders, and a cold head in thermal contact with the working gas in the second cylinder. It comprises:

Malaker

1989-01-01

202

Experiment and simulation on the performance of an autocascade refrigeration system using carbon dioxide as a refrigerant  

Microsoft Academic Search

The main purpose of this study is to investigate the performance of an autocascade refrigeration system using zeotropic refrigerant mixtures of R744\\/134a and R744\\/290. One of the advantages of this system is the possibility of keeping the highest pressure of the system within a limit by selecting the composition of a refrigerant mixture as compared to that in the vapor

S. G Kim; M. S Kim

2002-01-01

203

Carbon dioxide emission implications if hydrofluorocarbons are regulated: a refrigeration case study.  

PubMed

The U.S. is strongly considering regulating hydrofluorocarbons (HFCs) due to their global climate change forcing effects. A drop-in replacement hydrofluoroether has been evaluated using a gate-to-grave life cycle assessment of greenhouse gas emissions for the trade-offs between direct and indirect carbon dioxide equivalent emissions compared to a current HFC and a historically used refrigerant. The results indicate current regulations being considered may increase global climate change. PMID:20050659

Blowers, Paul; Lownsbury, James M

2010-03-01

204

Magnetic Refrigeration Development  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

205

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

Adsorption of Hydrofluorocarbons HFC-134 and HFC-134A on X and Y Zeolites: Effect of Ion volumetric and calorimetric techniques. The species and number of ions present in the zeolite strongly. The selectivity is considerably higher in X than in Y zeolites because of the larger number of nonframework ions

Siperstein, Flor R.

206

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

E-print Network

to 50-200 C for hot water and steam A great benefit is that the cycle can be used as a cooling system a refrigeration cycle for heating is referred to as a heat gif heating is referred to as a heat pump (mostly based on a vapour-compression cycle) /heat_pump.g Heat pumps make use of low- temperature (waste) heat, replacing

Zevenhoven, Ron

207

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

208

Measurements with a recuperative superfluid Stirling refrigerator  

SciTech Connect

A superfluid Stirling refrigerator cooled to 168 mK using a 4.9% {sup 3}He- {sup 4}He mixture and exhausting its waste heat at 383 mK. Cooling power versus temperature and speed is presented for 4.9%, 17%, and 36% mixtures. At the highest concentration, a dissipation mechanism of unknown origin is observed.

Watanabe, A.; Swift, G.W.; Brisson, J.G.

1995-08-01

209

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

210

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

211

Analysis of Solar features behavior using HELIO/HFC  

NASA Astrophysics Data System (ADS)

The Heliospheric Feature Catalogue (HFC) developed in the FP7 HELIO program gives access to the description of several features, extending in time, for some of them from 1996 to now. The concerned features are: Filaments, prominences, photospheric and coronal active regions, coronal holes, sunspots and radio type III. We present here an overview of the way features behave during the Solar cycle, showing that some of their characteristics are very cycle-dependant while some others seem to be independent.

Aboudarham, Jean; Bonnin, Xavier; Renié, Christian

2014-05-01

212

Viscosity of Gaseous HFC125 (Pentafluoroethane) Under High Pressures  

Microsoft Academic Search

This paper reports experimental results lor the viscosity of gaseous HFC-125 (pentafluoroethane) under high pressures. The measurements were carried out with an oscillating-disk viscometer of the Maxwell type at temperatures from 298.15 to 423.15 K and at pressures up to the saturated vapor pressures at each temperature at subcritical conditions or up to 9 MPa at supercritical temperatures. Intermolecular scaling

M. Takahashi; N. Shibasaki-Kitakawa; C. Yokoyama

1999-01-01

213

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

214

Handling and disposal of polyol ester refrigeration lubricants  

SciTech Connect

With the introduction of hydrofluorocarbon (HFC) refrigerants there has been a move away from conventional mineral oil basestocks to refrigerant lubricants based on polyol esters. As with all new applications there is an onus upon responsible manufacturers to proactively provide competent advice on the use and disposal of these new substances. The purpose of this paper is to give an overview of this area. The following areas are reviewed: storage and logistical issues -- regulatory issues, storage conditions, specifications; handling of polyol ester basestocks -- toxicity, vapor inhalation, skin irritancy, protective clothing advice; addivated oils -- general review, issues around the use of phosphates; used oils -- potential breakdown products, potential toxicological concerns; and disposal and re-use -- biodegradability, ecotoxicity, disposal by incineration, recycling.

Randles, S.J.; Penman, M.G.

1995-12-31

215

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...

216

Monitoring refrigeration energy useage  

Microsoft Academic Search

Refrigerators use more energy than any other kitchen appliance -- an unsurprising fact considering that refrigerators operate 24 hours a day, 365 days a year to keep food at a safe temperature. In many low-income households, refrigerators eat up more than half the electricity consumed in one year. And if the refrigerator in a family's home is functioning poorly, the

J. Cavallo; J. Mapp

2000-01-01

217

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

218

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

219

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

220

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 ...

221

Rate constants for the reactions of OH with HFC-134a (CF3CH2F) and HFC-134 (CHF2CHF2)  

NASA Technical Reports Server (NTRS)

Measurements of rate constants for HFC-134 (CF2HCF2H) relative to CH3CCl3, HFC-125, and HFC-134a are reported. The measurements were made in a slow-flow, temperature controlled photochemical reactor, and were based on relative rates of disappearance of the parent compounds as measured by FTIR spectroscopy. Hydroxyl radicals were generated by 254-nm photolysis of O3 in the presence of water vapor. NASA/JPL rate constants for the reference compounds are used to derive temperature-dependent rate constants of both compounds. Rate constants obtained from the different reference compounds are in excellent agreement. The presently recommended rate constant for HFC-134a is about 25 percent too high.

Demore, W. B.

1993-01-01

222

Flammability limits of isobutane and its mixtures with various gases  

Microsoft Academic Search

Flammability limits of isobutane and five kinds of binary mixtures of isobutane were measured by the ASHRAE method. Propane, nitrogen, carbon dioxide, chloroform, and HFC-125 (1,1,1,2,2-pentafluoroethane) were used as the counter part gases in the mixtures. The observed data were analyzed using the equations based on Le Chatelier's formula. The flammability limits of mixtures with propane were well explained by

Shigeo Kondo; Kenji Takizawa; Akifumi Takahashi; Kazuaki Tokuhashi; Akira Sekiya

2007-01-01

223

An investigation of the performance of a scroll compressor under liquid refrigerant injection  

Microsoft Academic Search

In this study, fundamental and practical influence of liquid refrigerant injection on the performance of a refrigerant scroll compressor has been investigated experimentally and theoretically. In the theoretical analysis, a compression model of vapor\\/liquid mixture is developed by taking account of heat transfer from the cylinder wall to suction, compression and injection refrigerant. An experiment has been done under the

Asit K. Dutta; Tadashi Yanagisawa; Mitsuhiro Fukuta

2001-01-01

224

Method and refrigerants for replacing existing refrigerants in centrifugal compressors  

SciTech Connect

This patent describes a method for replacing an existing refrigerant in a centrifugal compressor. It comprises selecting a desired impeller Mach number for the centrifugal compressor; selecting a base refrigerant constituent; combining at least one additive refrigerant constituent with the base refrigerant constituent to form a replacement refrigerant having at least one physical or chemical property different from the existing refrigerant and substantially providing the desired impeller Mach number in the centrifugal compressor; and replacing the existing refrigerant with the replacement refrigerant.

Kopko, W.L.

1991-12-31

225

Liquid-air partition coefficients of 1,1-difluoroethane (HFC152a), 1,1,1-trifluoroethane (HFC143a), 1,1,1,2-tetrafluoroethane (HFC134a), 1,1,1,2,2-pentafluoroethane (HFC125) and 1,1,1,3,3-pentafluoropropane (HFC245fa).  

PubMed

Blood-air and tissue-blood coefficients (lambda) are essential to characterize the uptake and disposition of volatile substances, e.g. by physiologically based pharmacokinetic (PBPK) modelling. Highly volatile chemicals, including many hydrofluorocarbons (HFC) have low solubility in liquid media. These characteristics pose challenges for determining lambda values. A modified head-space vial equilibrium method was used to determine lambda values for five widely used HFCs. The method is based on automated head-space gas chromatography and injection of equal amount of chemical in two head-space vials with identical air phase volumes but different volumes of the liquid phase. The liquids used were water (physiological saline), fresh human blood, and olive oil. The average lambda values (n = 8) were as follows: 1,1-difluoroethane (HFC152a) - 1.08 (blood-air), 1.11 (water-air) and 5.6 (oil-air); 1,1,1-trifluoroethane (HFC143a) - 0.15, 0.15 and 1.90; 1,1,1,2-tetrafluoroethane (HFC134a) - 0.36, 0.35 and 3.5; 1,1,1,2,2-pentafluoroethane (HFC125) - 0.083, 0.074 and 1.71; and 1,1,1,3,3-pentafluoropropane (HFC245fa) - 0.62, 0.58 and 12.1. The lambda values appeared to be concentration-independent in the investigated range (2-200 ppm). In spite of the low lambda values, the method errors were modest, with coefficients of variation of 9, 11 and 10% for water, blood and oil, respectively. PMID:19701883

Ernstgård, Lena; Lind, Birger; Andersen, Melvin E; Johanson, Gunnar

2010-01-01

226

Optimal refrigerator  

E-print Network

We study a refrigerator model which consists of two $n$-level systems interacting via a pulsed external field. Each system couples to its own thermal bath at temperatures $T_h$ and $T_c$, respectively ($\\theta\\equiv T_c/T_hrefrigerator functions in two steps: thermally isolated interaction between the systems driven by the external field and isothermal relaxation back to equilibrium. There is a complementarity between the power of heat transfer from the cold bath and the efficiency: the latter nullifies when the former is maximized and {\\it vice versa}. A reasonable compromise is achieved by optimizing the product of the heat-power and efficiency over the Hamiltonian of the two system. The efficiency is then found to be bounded from below by $\\zeta_{\\rm CA}=\\frac{1}{\\sqrt{1-\\theta}}-1$ (an analogue of the Curzon-Ahlborn efficiency), besides being bound from above by the Carnot efficiency $\\zeta_{\\rm C} = \\frac{1}{1-\\theta}-1$. The lower bound is reached in the equilibrium limit $\\theta\\to 1$. The Carnot bound is reached (for a finite power and a finite amount of heat transferred per cycle) for $\\ln n\\gg 1$. If the above maximization is constrained by assuming homogeneous energy spectra for both systems, the efficiency is bounded from above by $\\zeta_{\\rm CA}$ and converges to it for $n\\gg 1$.

Armen E. Allahverdyan; Karen Hovhannisyan; Guenter Mahler

2010-07-25

227

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

228

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

229

Flammability limits of isobutane and its mixtures with various gases.  

PubMed

Flammability limits of isobutane and five kinds of binary mixtures of isobutane were measured by the ASHRAE method. Propane, nitrogen, carbon dioxide, chloroform, and HFC-125 (1,1,1,2,2-pentafluoroethane) were used as the counter part gases in the mixtures. The observed data were analyzed using the equations based on Le Chatelier's formula. The flammability limits of mixtures with propane were well explained by the original Le Chatelier's formula. The flammability limits of mixtures with nitrogen and the ones with carbon dioxide were adequately analyzed by the extended Le Chatelier's formula. It was found that the extended Le Chatelier's formula is also applicable to the flammability limits of mixtures with chloroform and HFC-125. PMID:17433539

Kondo, Shigeo; Takizawa, Kenji; Takahashi, Akifumi; Tokuhashi, Kazuaki; Sekiya, Akira

2007-09-30

230

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

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.

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

1994-05-27

232

Multiannual Top-Down Estimate of HFC-23 Emissions in East Asia.  

PubMed

Trifluoromethane (CHF3, HFC-23), with a 100-year global warming potential (GWP) of 12400, is regulated under the Kyoto Protocol. HFC-23 emissions in East Asia, especially in China, are currently thought to represent the majority of global HFC-23 emissions. This study provides both a bottom-up emission inventory and the multiannual top-down estimate of HFC-23 emissions in East Asia during 2007-2012. The new bottom-up inventory yields improved simulated HFC-23 mixing ratios compared to previous bottom-up inventories. The top-down estimate uses inverse modeling to further improve the model-measurement agreement. Results show that China contributed 94-98% of all HFC-23 emissions in East Asia. Annual a posteriori emissions from China were around 6.3 Gg/yr during the period 2007-2010 after which they increased to 7.1 ± 0.7 Gg/yr in 2011 and 8.8 ± 0.8 Gg/yr in 2012. For the first time, this study also provides a top-down estimate of HFC-23/HCFC-22 (chlorodifluoromethane, CHClF2) coproduction ratios in non-CDM (Clean Development Mechanism) HCFC-22 production plants as well as in all HCFC-22 production plants in China. PMID:25785483

Fang, X; Stohl, A; Yokouchi, Y; Kim, J; Li, S; Saito, T; Park, S; Hu, J

2015-04-01

233

ALTERNATIVES FOR OZONE-DEPLETING REFRIGERANTS  

EPA Science Inventory

The paper gives results of tests of 2 of 11 compounds and several mixtures selected for intensive evaluation from about 40 new synthesized compounds that may serve as environmentally safe and effective refrigerant alternatives over the long term. he two compounds are: 1, 1, 1, 2,...

234

Determining rate of refrigerant emissions from nonprofessional automotive service through a southern California field study  

NASA Astrophysics Data System (ADS)

Vehicle owners in the United States can recharge their vehicles' air conditioning systems with small containers of hydrofluorocarbon-134a (HFC-134a, CH2FCF3). This refrigerant, with a Global Warming Potential of 1430, may be emitted to the atmosphere during the recharging operation and from the residual heel in partially used containers, contributing to climate change. A field study was conducted in southern California to quantify the rate of refrigerant emissions from nonprofessional recharging practices and identify emission mitigation opportunities. Based on the results of the study, an average of 489 g of HFC-134a is used when recharging the sample vehicles with an average nominal charge of 858 g. An average 67% of the container content is effectively charged into the systems, 11% of the refrigerant is released during service, and the remaining 22% is left in the containers after operations are completed. A comparison with two other independent studies indicates that the findings of the current study may be applicable not only to southern California, but also to the entire U.S.

Zhan, Tao; Clodic, Denis; Palandre, Lionel; Trémoulet, Arnaud; Riachi, Youssef

2013-11-01

235

Alternate refrigerants and lubricants for the microclimate cooling system. Final report, December 1991-March 1992  

SciTech Connect

This research identified, explored, and evaluated the use of alternative refrigerants and lubricants in vapor compression cycle for refrigeration. With impending phaseouts of chlorofluorocarbons (CFC`s), there is an immediate need to find suitable replacements for use existing systems, as well as new systems designed to operate with the new substances. The alternative refrigerants and lubricants have certain problems when used in retrofitted systems. Differences in properties must also be considered when designing a system for use with the alternatives. For Microclimate Cooling Systems, HFC-134a is considered when designing a system for use with the alternatives. For Microclimate Cooling Systems, HFC-134A is considered to be the best candidate. R-134a requires a higher pressure increase to achieve a good refigeration cycle; however, 134a necessities the use of a new lubricant. For 134a, a polyolester lubricant is the best choice. It has desirable properties and a very low ecotoxicity rating. It is also compatible with CFC-12. This allows a system run with an ester based lubricant and R-12 to be easily retrofitted to operate on 134.

Wolfson, M.W.

1992-09-01

236

Refrigerant Leakage Detection and Diagnosis for a Distributed Refrigeration System  

Microsoft Academic Search

A new technique to detect and diagnose leakage in a distributed refrigeration system is proposed in this paper. Unlike a simple refrigeration system of an HVAC system, a distributed refrigeration system, such as the refrigeration system in a supermarket, consists of several racks of compressors and evaporators, large condenser systems on the roof, meters of refrigerant piping systems, and liquid

Kriengkrai Assawamartbunlue; Michael J. Brandemuehl

2006-01-01

237

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

238

Toxicological Evaluation of 1,1,1,2,2-Pentafluoroethane (HFC125)  

Microsoft Academic Search

Toxicological Evaluation of 1,1,1,2,2-Pentafluoroethane (HFC125). Kawano, T., Trochimowicz, H. J., Maliverno, G., and Rusch, G. M. (1995). Fundam. Appl. Toxicol. 28, 223-231.Acute, subacute, and subchronic inhalation toxicity studies, developmental toxicity studies, a cardiac sensitization evaluation, and mutagenicity assays were conducted with pentafluoroethane (HFC-125). In the acute study, rats were exposed to a single concentration of 800,000 ppm for 4 hr.

Toshihiko Kawano; Henry J. Trochimowicz; Giuseppe Malinverno; George M. Rusch

1995-01-01

239

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

240

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

241

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

242

Monitoring refrigeration energy useage.  

SciTech Connect

Refrigerators use more energy than any other kitchen appliance -- an unsurprising fact considering that refrigerators operate 24 hours a day, 365 days a year to keep food at a safe temperature. In many low-income households, refrigerators eat up more than half the electricity consumed in one year. And if the refrigerator in a family's home is functioning poorly, the cost to the consumer can be enormous. Discovering whether an existing refrigerator is operating inefficiently enough to warrant replacing it is an extremely difficult task for a resident who sees only a monthly electric bill. Only by knowing the approximate usage of the existing unit can anyone tell whether it would pay to buy a new, energy-efficient refrigerator. The savings from replacing older refrigerators can be substantial, and collecting the data needed to determine when refrigerators should be replaced is easier and less costly than one might think. In both Chicago and New York City, replacing existing units cut refrigerator electricity usage by more than 50%. Monitoring to develop an average usage for the existing stock of refrigerators is a task that can be completed by maintenance staff in a reasonably short time -- and identifying poorly performing units that should be immediately replaced can take just two hours of monitoring.

Cavallo, J.; Mapp, J.; Energy Systems; Wisconsin Energy Bureau

2000-05-01

243

Isochoric p–?–T Measurements for Binary Refrigerant Mixtures Containing Difluoromethane (R32), Pentafluoroethane (R125), 1,1,1,2-Tetrafluoroethane (R134a), and 1,1,1-Trifluoroethane (R143a) from 200 to 400 K at Pressures to 35 MPa  

Microsoft Academic Search

The p–?–T relationships were measured for binary refrigerant mixtures by an isochoric method with gravimetric determinations of the amount of substance. Temperatures ranged from 200 to 400 K, while pressures extended up to 35 MPa. Measurements were conducted on compressed gas and liquid samples with the following mole fraction compositions: 0.4997 R32+0.5003 R134a, 0.3288 R32+0.6712 R134a, 0.4996 R32+0.5004 R125, 0.5001

J. W. Magee; W. M. Haynes

2000-01-01

244

Dryout Quality for Refrigerants Flowing in Horizontal Evaporator Tubes  

NASA Astrophysics Data System (ADS)

The present paper reports an investigation of the dryout quality for refrigerants flowing in horizontal evaporator tubes. Experiments were made for the flow of boiling HFC-134a and HCFC-22 inside smooth tubes and a spirally grooved (micro-fin) tube. At given conditions, dryout proceeded over a certain quality range. Therefore two dryout qualities were defined; dryout inception quality at which the circumferentially averaged (axially local) heat transfer coefficient began to decrease rapidly, and dryout completion quality at which the decrease in the heat transfer coefficient ended. Based on the experimental data, the characteristics of both dryout qualities were clarified, and thereby the dryout qualities were classified into three characteristic regimes for the smooth tube and two regimes for the micro-fin tube. A dimensionless correlation of each dryout quality, which can reproduce the measurement successfully, was developed for the respective tubes.

Mori, Hideo; Kakimoto, Yasushi; Ohishi, Katsumi

245

Top-down Estimation of Emission Strengths of Major Anthropogenic Halocarbons from China Using High-frequency Measurements with HCFC22\\/HFC23 as Tracers  

Microsoft Academic Search

In this study we present calculations of Chinese emissions of most major anthropogenic halocarbon species, including CFCs (CFC-11, CFC-12), HCFCs (HCFC-22, HCFC-141b, HCFC-142b), HFCs (HFC-134a, HFC-125, HFC-152a, HFC-23, HFC-143a, HFC-32), H-1211, PFCs(CF4, PFC-116, PFC-218) and solvents (CH3Cl, CH2Cl2, CHCl3, CCl4), using data from high-frequency measurements made with a automated GC-MSD instrument (``Medusa'') operated at Gosan station (126°E, 33°N, Jeju Island,

K. Kim; J. Kim; S. Li; J. Muhle; A. Stohl; S. Kim; G. Lee; R. F. Weiss

2009-01-01

246

Refrigerator Based on Chemisorption  

NASA Technical Reports Server (NTRS)

Reversible chemical reaction generates pressurized oxygen for cooling. Concept for cryogenic refrigerator based on chemical absorption of oxygen by praseodymium/cerium oxide (PCO) compound. Refrigerator produces cryogenic liquid for cooling infrared sensors. Also used for liquefying air and separating oxygen from nitrogen in air. In chemisorption refrigerator, PCO alternately absorbs and desorbs oxygen depending on whether cooled or heated. One pair of compressors accepts oxygen while others releases it. Compressed oxygen liquefied when precooked and expanded.

Jones, Jack A.

1987-01-01

247

How to convert CFC12 chillers to HFC134A  

Microsoft Academic Search

With less than three years to go before CFC production comes to a halt, the need to retrofit, replace, or manage the containment of CFC-based HVAC systems is a pressing concern for everyone with equipment that runs on a CFC refrigerant today. For building owners and others whose properties are cooled by large tonnage centrifugal chillers operating on CFC, the

Bell

1993-01-01

248

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

249

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

250

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

251

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

252

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

253

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

254

Assessment of Environmentally Friendly Refrigerants for Window Air Conditioners  

SciTech Connect

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

Bansal, Pradeep [ORNL] [ORNL; Shen, Bo [ORNL] [ORNL

2014-01-01

255

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

256

Listeria monocytogenes survival in refrigerator dill pickles.  

PubMed

Listeria monocytogenes can survive and grow in refrigerated foods with pH values of approximately 4.0 to 5.0 and salt concentrations of 3 to 4%. Home-fermented refrigerator dill pickles fit this description. Contamination of this product with L. monocytogenes could cause serious problems because these items are not heated prior to consumption. L. monocytogenes survival and growth patterns were investigated in refrigerator dill pickles at 1.3, 3.8, and 7.6% salt concentrations. Pickling cucumbers were dipped into an inoculum of L. monocytogenes, brine mixtures were added, and cucumbers were held at room temperature for 1 week and then refrigerated for up to 3 months. The pH, NaCl percentage, titratable acidity percentage, and total populations of Listeria and aerobic, psychrotrophic, and lactic acid bacteria were measured at the addition of brine, after 2, 4, and 7 days of storage at room temperature, and then weekly during refrigerated storage. The initial Listeria population was 5.4 to 5.6 log CFU/cm2 on cucumber surfaces and 3.9 to 4.6 log CFU/g internally. There was an approximate 0.3- to 1-log increase during room temperature fermentation followed by a population decline during refrigerator storage, with a greater decrease in the brines with the highest NaCl concentration. Up to 49 days, the internal tissue of pickles with 1.3, 3.8, or 7.6% salt concentrations were presumptively positive for L. monocytogenes by the enrichment method, and at 91 days the surfaces of such pickles were still positive for L. monocytogenes. Populations of total aerobes and lactic acid bacteria increased during room temperature storage and decreased gradually during refrigerated storage. PMID:16300073

Kim, Jin Kyung; D'Sa, Elaine M; Harrison, Mark A; Harrison, Judy A; Andress, Elizabeth L

2005-11-01

257

Solubility, density and viscosity of mixtures of isobutane (R-600a) and a linear alkylbenzene lubricant oil  

Microsoft Academic Search

Isobutane (R-600a) is a well established environmentally friendly substitute for hydrofluorocarbon and chlorofluorocarbon refrigerants in vapor compression refrigeration applications. In order to improve the performance and reliability of compressors and refrigerators, the behavior of the thermophysical properties of refrigerant–lubricant mixtures must be well understood, as the choice of lubricant oil plays an important role in determining the system equalizing pressure

Moisés A. Marcelino Neto; Jader R. Barbosa Jr.

2010-01-01

258

An evaluation on the environmental consequences of residual CFCs from obsolete household refrigerators in China  

SciTech Connect

Chlorofluorocarbons (CFCs) contained in household refrigerators consist mainly of CFC-11 and CFC-12, which will be eventually released into the environment. Consequentially, environmental releases of these refrigerants will lead to ozone depletion and contribute significantly to the greenhouse effect, if waste refrigerators are not disposed of properly. In the present paper, the potential release of residual CFCs and their substitutes from obsolete household refrigerators in China is examined, and their contributions to ozone depletion and greenhouse effect are compared with those of other recognized ozone-depleting substances (ODS) and greenhouse gases (GHGs). The results imply that annual potential amounts of released residual CFC-11 and CFC-12 will reach their maximums at 4600 and 2300 tons, respectively in 2011, and then decrease gradually to zero until 2020. Meanwhile, the amounts of their most widely used substitutes HCFC-141b and HFC-134a will keep increasing. Subsequently, the contribution ratio of these CFCs and their substitutes to ozone depletion will remain at 25% through 2011, and reach its peak value of 34% by 2018. The contribution to greenhouse effect will reach its peak value of 0.57% by 2010. Moreover, the contribution ratio of these CFCs to the total global release of CFCs will steadily increase, reaching its peak of 15% by 2018. Thus, this period from 2010 to 2018 is a crucial time during which residual CFCs and their substitutes from obsolete household refrigerators in China will contribute significantly to ozone depletion.

Zhao Xiangyang; Duan Huabo [Department of Environmental Science and Engineering, Tsinghua University, Beijing (China); Li Jinhui, E-mail: jinhui@tsinghua.edu.cn [Department of Environmental Science and Engineering, Tsinghua University, Beijing (China)

2011-03-15

259

An evaluation on the environmental consequences of residual CFCs from obsolete household refrigerators in China.  

PubMed

Chlorofluorocarbons (CFCs) contained in household refrigerators consist mainly of CFC-11 and CFC-12, which will be eventually released into the environment. Consequentially, environmental releases of these refrigerants will lead to ozone depletion and contribute significantly to the greenhouse effect, if waste refrigerators are not disposed of properly. In the present paper, the potential release of residual CFCs and their substitutes from obsolete household refrigerators in China is examined, and their contributions to ozone depletion and greenhouse effect are compared with those of other recognized ozone-depleting substances (ODS) and greenhouse gases (GHGs). The results imply that annual potential amounts of released residual CFC-11 and CFC-12 will reach their maximums at 4600 and 2300 tons, respectively in 2011, and then decrease gradually to zero until 2020. Meanwhile, the amounts of their most widely used substitutes HCFC-141b and HFC-134a will keep increasing. Subsequently, the contribution ratio of these CFCs and their substitutes to ozone depletion will remain at 25% through 2011, and reach its peak value of 34% by 2018. The contribution to greenhouse effect will reach its peak value of 0.57% by 2010. Moreover, the contribution ratio of these CFCs to the total global release of CFCs will steadily increase, reaching its peak of 15% by 2018. Thus, this period from 2010 to 2018 is a crucial time during which residual CFCs and their substitutes from obsolete household refrigerators in China will contribute significantly to ozone depletion. PMID:21093246

Zhao, Xiangyang; Duan, Huabo; Li, Jinhui

2011-03-01

260

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

261

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

262

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 AND REFRIGERATION EQUIPMENT By Charles Butler (Section 1), Joseph W. Slavin (Sections 1, 2, and 3), Max Patashnik

263

Ejectors: applications in refrigeration technology  

Microsoft Academic Search

This paper provides a literature review on ejectors and their applications in refrigeration. A number of studies are grouped and discussed in several topics, i.e. background and theory of ejector and jet refrigeration cycle, performance characteristics, working fluid and improvement of jet refrigerator. Moreover, other applications of an ejector in other types of refrigeration system are also described.

Kanjanapon Chunnanond; Satha Aphornratana

2004-01-01

264

Experimental study of PVT properties of HFC-125 (CHF{sub 2}CF{sub 3})  

SciTech Connect

Pressure-volume temperature (PVT) properties and vapor pressures of HFC-125 (pentafluoroethane; CHF{sub 2}CF{sub 3}) have been experimentally obtained. Vapor pressures of HFC-125 have been measured in the range of temperatures from 223 to 338 K and pressures up to 3.54 MPa with uncertainties of 5 mK and 2.5 kPa, respectively. The vapor pressure equation for this substance was correlated based on the present data. PVT properties of HFC-125 have been determined with a constant-volume apparatus in the range of temperatures from 280 to 473 K, pressures up to 17 MPa, and densities up to 1145 kg, m{sup {minus}3} with uncertainties of 5 mK, 2.5 kPa, and 0.01%, respectively. All of the available experimental PVT property data were compared with the equation of state correlated by Wilson et al.

Oguchi, K.; Murano, A.; Omata, K., Yada, N. [Kanagawa Inst. of Technology, Kanagawa (Japan)

1996-01-01

265

Toxicological evaluation of 1,1,1,2,2-pentafluoroethane (HFC-125).  

PubMed

Acute, subacute, and subchronic inhalation toxicity studies, developmental toxicity studies, a cardiac sensitization evaluation, and mutagenicity assays were conducted with pentafluoroethane (HFC-125). In the acute study, rats were exposed to a single concentration of 800,000 ppm for 4 hr. Ataxic gait and abnormal respiration were observed during exposure but not after exposure. There was no mortality or other signs of toxicity. Repeated exposures of rats to 50,000 ppm, 6 hr/day, 5 days/week for either 4 or 13 weeks elicited no effects on body weight, food consumption, clinical signs, hematology, biochemistry, urinalysis, organ weight, or tissue morphology. Positive evidence of cardiac sensitization in response to an intravenous epinephrine challenge in dogs was seen at 100,000 ppm and above, but not at 75,000 ppm. HFC-125 was not mutagenic in Salmonella typhimurium and Escherichia coli strains at concentrations of 20 to 100% (v/v) with and without activation. No evidence of clastogenic activity was observed in cultured Chinese hamster ovary (CHO) cells or human lymphocytes at < or = 70% HFC-125 when treatments were conducted for 3-4 hr with activation or for 24 and 48 hr (human lymphocytes only) without activation. However, a statistically significant increase in chromosomally aberrant cells was observed in CHO cells at 60% HFC-125 when treatment without activation was extended to 48 hr. The biological significance of this effect is questionable since signs of severe toxicity were also present. In vivo, no micronuclei were induced in mouse bone marrow at concentrations as high as 600,000 ppm HFC-125 for a 6-hr exposure. In addition, HFC-125 did not induce embryotoxic or teratogenic effects in either the rat or the rabbit at exposure concentrations as high as 50,000 ppm. PMID:8835232

Kawano, T; Trochimowicz, H J; Malinverno, G; Rusch, G M

1995-12-01

266

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

267

Refrigerant Compliance Updated: July 12, 2012  

E-print Network

Refrigerant Compliance Policy Updated: July 12, 2012 #12;TABLE OF CONTENTS The official version ........................................................................................................ 3 A. Refrigerant Compliance Manager (RCM).................................................................. 3 B. Refrigerant Inventory Coordinator (RIC

Holland, Jeffrey

268

Leakage Flow Characteristics in Expander for CO2 Refrigeration Cycle  

NASA Astrophysics Data System (ADS)

Carbon dioxide (CO2) is considered to be an alternative to HFC refrigerants due to its non-flammability, non-toxicity and small global warming potential. To improve the performance of the CO2 refrigeration cycle, using an expander as an expansion device to recover a throttling loss has been examined. Since an inlet condition of the expander is supercritical and an exit is subcritical, leakage through a narrow clearance in the expander becomes a transcritical flow where the condition changes from the supercritical to the subcritical. It is necessary to clarify the characteristics of the transcritical leakage flow through the narrow clearance, because the leakage flow has serious influence on the expander performance. In this study, the transcritical leakage flow is modeled analytically and the flow characteristic is examined by the model. The calculated mass flow rate agrees with the experimental one. It is found that frictional loss accounts for a half of pressure drop both in the supercritical and two phase region at any inlet temperature tested in this study. In addition, the sealing effect of oil on the transcritical leakage flow rate is shown to be little.

Fukuta, Mitsuhiro; Adachi, Masaaki; Yanagisawa, Tadashi; Ogi, Yasuhiro

269

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

270

Optomechanics: Photons refrigerating phonons  

NASA Astrophysics Data System (ADS)

Optomechanics is a promising route towards the observation of quantum effects in relatively large structures. Three papers, each discussing a different implementation, now combine optical sideband and cryogenic cooling to refrigerate mechanical resonators to fewer than 60 phonons.

Cleland, Andrew

2009-07-01

271

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...

272

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

273

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

274

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 (...

275

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 (...

276

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...

277

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...

278

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

279

The effect of refrigerants in the mixed lubrication regime  

SciTech Connect

Because of environmental concerns, CFC (chlorofluorocarbon) refrigerants must be replaced with HFCs (hydrofluorocarbons). As a result, many tribological problems are caused especially in rotary piston compressors. To solve the problem, the effects of refrigerants on friction and wear characteristics of the oil and refrigerant mixtures at the mixed lubrication regime are investigated. The difference in refrigerants are clearly observed not only in boundary but also in the mixed lubrication regime. The effects of operating conditions on sliding conditions and experimental results are also discussed. It is concluded that for practical application where long life is essential, experiments must be conducted under the mixed lubrication regime. Also, the importance of defining the lubrication regime in terms of film parameter is emphasized.

Mizuhara, Kazuyuki [Mechanical Engineering Lab., Tsukuba (Japan). Tribology Div.; Tomimoto, Makoto [Hoya Corp., Kitaoka (Japan)

1997-12-31

280

21 CFR 1250.34 - Refrigeration equipment.  

Code of Federal Regulations, 2010 CFR

...Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment. Each refrigerator shall be equipped with a thermometer located in the warmest portion thereof. Waste water drains from ice boxes, refrigerating equipment, and refrigerated...

2010-04-01

281

21 CFR 1250.34 - Refrigeration equipment.  

Code of Federal Regulations, 2011 CFR

...Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment. Each refrigerator shall be equipped with a thermometer located in the warmest portion thereof. Waste water drains from ice boxes, refrigerating equipment, and refrigerated...

2011-04-01

282

21 CFR 1250.34 - Refrigeration equipment.  

Code of Federal Regulations, 2013 CFR

...Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment. Each refrigerator shall be equipped with a thermometer located in the warmest portion thereof. Waste water drains from ice boxes, refrigerating equipment, and refrigerated...

2013-04-01

283

21 CFR 1250.34 - Refrigeration equipment.  

Code of Federal Regulations, 2014 CFR

...Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment. Each refrigerator shall be equipped with a thermometer located in the warmest portion thereof. Waste water drains from ice boxes, refrigerating equipment, and refrigerated...

2014-04-01

284

21 CFR 1250.34 - Refrigeration equipment.  

Code of Federal Regulations, 2012 CFR

...Land and Air Conveyances, and Vessels § 1250.34 Refrigeration equipment. Each refrigerator shall be equipped with a thermometer located in the warmest portion thereof. Waste water drains from ice boxes, refrigerating equipment, and refrigerated...

2012-04-01

285

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

286

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

287

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

288

Waste Heat Recovery from Refrigeration  

E-print Network

heat recovery from refrigeration machines is a concept which has great potential for implementation in many businesses. If a parallel requirement for refrigeration and hot water exists, the installation of a system to provide hot water as a by...

Jackson, H. Z.

1982-01-01

289

Superfluid Stirling refrigerator with a counterflow regenerator  

SciTech Connect

The superfluid Stirling refrigerator (SSR) uses a [sup 3]He-[sup 4]He liquid mixture as a working fluid. It operates at temperatures below 2 K where the [sup 4]He component of the working fluid is superfluid. The [sup 3]He component of the working fluid, to first approximation, behaves thermodynamically like an ideal gas in the inert background of superfluid [sup 4]He. Using pistons equipped with a superleak bypass, it is possible to expand and compress the [sup 3]He solute gas.'' The SSR is a Stirling machine equipped with these superleaked'' pistons to take advantage of the properties of the [sup 3]He solute to cool below 1 K. The proof of principle was shown by Kotsubo and Swift in 1990. There are three other techniques for cooling below 1 K: (1) the [sup 3]He-[sup 4]He dilution refrigerator which utilizes the endothermic heat of mixing of [sup 3]He into [sup 4]He to reach temperatures below 0.010 K; (2) the evaporation of [sup 3]He which can reach temperatures of 0.3 K; and, (3) adiabatic demagnetization of a paramagnetic salt. There are several advantages of the SSR over each of the other techniques. The power consumption of a dilution refrigerator is typically on the order of kilowatts; whereas, the SSR consumes hundreds of watts. The SSR has the potential to cool below 0.3 K and out-perform the evaporative [sup 3]He refrigerator. Adiabatic demagnetization often requires magnetic shielding between the refrigerator and the object to be cooled; obviously, the SSR requires no such shielding. There is an interest in developing subkelvin cryocoolers for satellite-borne X-ray and infrared detectors. In space applications, the power consumption of an SSR can be reduced to tens of watts. This coupled with the SSR's insensitivity to a zero G environment makes it an attractive option to cool detectors in space.

Brisson, J.G.; Swift, G.W.

1992-01-01

290

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

291

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

292

Japanese refrigerators field testing  

SciTech Connect

Residential refrigerators consume the equivalent of 1700 megawatts (MW) of baseload power in the Bonneville Power Administration (BPA) service area. Japanese manufacturers have designed refrigerator units that appear more energy efficient than some currently available American models. This report summarizes preliminary findings from field testing of 12 refrigerators of Japanese manufacture to evaluate annual kilowatt hour (kWh) use during actual operation. The units have also undergone laboratory testing sponsored by BPA at ETL Testing Laboratories, Inc. in Cortland, New York. A final report of the project -- due at the end of 1989 -- will correlate in detail the results of field and laboratory tests in comparison to performance ratings determined by the manufacturer.

Lou, A.T.

1989-03-01

293

Japanese Refrigerators Field Testing.  

SciTech Connect

Residential refrigerators consume the equivalent of 1700 megawatts (MW) of baseload power in the Bonneville Power Administration (BPA) service area. Japanese manufacturers have designed refrigerator units that appear more energy efficient than some currently available American models. This report summarizes preliminary findings from field testing of 12 refrigerators of Japanese manufacture to evaluate annual kilowatt hour (kWh) use during actual operation. The units have also undergone laboratory testing sponsored by BPA at ETL Testing Laboratories, Inc. in Cortland, New York. A final report of the project -- due at the end of 1989 -- will correlate in detail the results of field and laboratory tests in comparison to performance ratings determined by the manufacturer.

Lou, Albert T.

1989-03-01

294

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

295

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

296

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...

297

Model Based Control Refrigeration Systems  

E-print Network

Model Based Control of Refrigeration Systems Ph.D. Thesis Lars Finn Sloth Larsen Central R & D University, Denmark. The work has been carried out at the Central R&D - Refrigeration and Air Conditioning The subject for this Ph.D. thesis is model based control of refrigeration systems. Model based control covers

298

Status Of Sorption Cryogenic Refrigeration  

NASA Technical Reports Server (NTRS)

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

Jones, Jack A.

1988-01-01

299

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...

300

Refrigerants in Transition  

E-print Network

on the magnetocaloric effect which observes that magnetic materials heat in a magnetic field and cool upon removal from it. It has been said to be up to 40 times more efficient and 257. less expensive than conventional gas cycle refrigeration for very low... refrigeration is based on the magnetocaloric effect which observes that magnetic materials heat in a magnetic field and cool upon removal from it. It has been said to be up to 40 times more efficient and 25% less expensive than conventional gas cycle...

Stouppe, D. E.

301

Refrigeration for photomultipliers.  

PubMed

A closed-cycle mechanical refrigeration system has been adapted to cool photomultipliers automatically. Temperature is adjustable between +50 degrees and -55 degrees C and is stable to within +/-0.30 degrees C. An important feature of the design is the flexible connection to the cold box which allows extensive freedom of motion; this freedom is particularly important in astronomy where the cold box is mounted on the end of a telescope. Liquid Freon refrigerants have been used to cool photomultipliers for rocket flights. A brief description of two methods is given. PMID:20057521

Broadfoot, A L

1966-08-01

302

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

SciTech Connect

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

Shrestha, Som S [ORNL] [ORNL; Sharma, Vishaldeep [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL

2014-01-01

303

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

304

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

305

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

NASA Astrophysics Data System (ADS)

A protocol was developed to define calorimeter operating pressures for nonazeotropic refrigerant mixtures (NARM's) 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 NARM's 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 NARM's 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 NARM's 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

306

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

NASA Astrophysics Data System (ADS)

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.; Sridharan, Arunkumar; Atrey, M. D.

2014-01-01

307

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

308

Dilution refrigeration for space applications  

NASA Technical Reports Server (NTRS)

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

Israelsson, U. E.; Petrac, D.

1990-01-01

309

Step piston pulse tube refrigerator  

NASA Astrophysics Data System (ADS)

In this paper, a numerical simulation is done for a step piston pulse tube refrigerator. The step piston pulse tube refrigerator is a modification of an inertance tube pulse tube refrigerator, which has a step piston compressor. The step piston in a step cylinder forms a compression space which is connected to the after cooler and an expansion space which is connected to the buffer. Numerical simulation shows that it is more effective at higher refrigeration temperature. It also shows there is an optimum swept volume ratio of the expansion space over the compression space, and an optimum diameter and length of the inertance tube for a given refrigerator.

Zhu, Shaowei

2014-11-01

310

Thermoacoustic engines and refrigerators  

SciTech Connect

We ordinarily think of a sound wave in a gas as consisting of coupled pressure and displacement oscillations. However, temperature oscillations always accompany the pressure changes. The combination of all these oscillations, and their interaction with solid boundaries, produces a rich variety of `thermoacoustic` effects. Although these effects as they occur in every-day life are too small to be noticed, one can harness extremely loud sound waves in acoustically sealed chambers to produce powerful heat engines, heat pumps and refrigerators. Whereas typical engines and refrigerators have crankshaft-coupled pistons or rotating turbines, thermoacoustic engines and refrigerators have at most a single flexing moving part (as in a loudspeaker) with no sliding seals. Thermoacoustic devices may be of practical use where simplicity, reliability or low cost is more important than the highest efficiency (although one cannot say much more about their cost-competitiveness at this early stage). This paper discusses the fundamentals of thermoacoustic engines and refrigerators, research in this field, and their commercial development. 16 refs., 5 figs.

Swift, G.W. [Los Alamos National Lab., NM (United States)

1995-07-01

311

Improved cryogenic refrigeration system  

NASA Technical Reports Server (NTRS)

Two-position shuttle valve simplifies valving arrangement and crank-shaft configuration in gas-balancing and Stirling-cycle refrigeration systems used to produce temperatures below 173 degrees K. It connects the displacer and regenerator alternately to the supply line or the return line of the compressor, and establishes constant pressure on the drive piston.

Higa, W. H.

1967-01-01

312

Auto defrost refrigerator  

Microsoft Academic Search

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

Schulze

1988-01-01

313

An International Standard Equation of State for the Thermodynamic Properties of HFC-125 (Pentafluoroethane)  

NASA Astrophysics Data System (ADS)

An 18-coefficient modified Benedict-Webb-Rubin equation of state for HFC-125 (pentafluoroethane) has been developed. Correlations of vapor pressure and saturated liquid density are also presented. This equation of state has been developed using experimental data for the relationship of pressure-volume-temperature of fluid, saturation properties, isochoric heat capacity data, and speed of sound data. The equation of state is valid in the superheated gaseous phase and the compressed liquid phase at pressures up to 68 MPa, densities to 1700 kg/m3, and temperatures from the triple point (172.52 K) to 475 K. This equation of state has been selected as an international standard formulation for HFC-125 based on an evaluation of the available equations of state by Annex 18 of the International Energy Agency.

Piao, Chun-Cheng; Noguchi, Masahiro

1998-07-01

314

An International Standard Equation of State for the Thermodynamic Properties of HFC125 (Pentafluoroethane)  

Microsoft Academic Search

An 18-coefficient modified Benedict–Webb–Rubin equation of state for HFC-125 (pentafluoroethane) has been developed. Correlations of vapor pressure and saturated liquid density are also presented. This equation of state has been developed using experimental data for the relationship of pressure-volume-temperature of fluid, saturation properties, isochoric heat capacity data, and speed of sound data. The equation of state is valid in the

Chun-Cheng Piao; Masahiro Noguchi

1998-01-01

315

10 CFR 429.42 - Commercial refrigerators, freezers, and refrigerator-freezers.  

Code of Federal Regulations, 2014 CFR

...refrigerator-freezers, self-contained commercial refrigerators, freezers, and refrigerator-freezers without doors, commercial ice-cream freezers, and commercial refrigeration equipment with two or more compartments (i.e., hybrid...

2014-01-01

316

10 CFR 429.42 - Commercial refrigerators, freezers, and refrigerator-freezers.  

Code of Federal Regulations, 2012 CFR

...refrigerator-freezers, self-contained commercial refrigerators, freezers, and refrigerator-freezers without doors, commercial ice-cream freezers, and commercial refrigeration equipment with two or more compartments (i.e., hybrid...

2012-01-01

317

10 CFR 429.42 - Commercial refrigerators, freezers, and refrigerator-freezers.  

Code of Federal Regulations, 2013 CFR

...refrigerator-freezers, self-contained commercial refrigerators, freezers, and refrigerator-freezers without doors, commercial ice-cream freezers, and commercial refrigeration equipment with two or more compartments (i.e., hybrid...

2013-01-01

318

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 to Part 305...Part 305—Refrigerators and Refrigerators-Freezers With Manual Defrost Range Information...

2010-01-01

319

10 CFR 429.14 - Residential refrigerators, refrigerator-freezers and freezers.  

Code of Federal Regulations, 2014 CFR

...residential refrigerators, refrigerator-freezers, and freezers...are applicable to residential refrigerators, refrigerator-freezers and freezers; and...the basic model has variable defrost control (in which...

2014-01-01

320

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 to Part 305...Part 305—Refrigerators and Refrigerators-Freezers With Manual Defrost Range Information...

2013-01-01

321

10 CFR 429.14 - Residential refrigerators, refrigerator-freezers and freezers.  

Code of Federal Regulations, 2013 CFR

...residential refrigerators, refrigerator-freezers, and freezers...are applicable to residential refrigerators, refrigerator-freezers and freezers; and...the basic model has variable defrost control (in which...

2013-01-01

322

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

Code of Federal Regulations, 2014 CFR

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

2014-01-01

323

10 CFR 429.14 - Residential refrigerators, refrigerator-freezers and freezers.  

Code of Federal Regulations, 2012 CFR

...residential refrigerators, refrigerator-freezers, and freezers...are applicable to residential refrigerators, refrigerator-freezers and freezers; and...the basic model has variable defrost control (in which...

2012-01-01

324

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 to Part 305...Part 305—Refrigerators and Refrigerators-Freezers With Manual Defrost Range Information...

2011-01-01

325

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 to Part 305...Part 305—Refrigerators and Refrigerators-Freezers With Manual Defrost Range Information...

2012-01-01

326

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...

327

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

328

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

329

Magnetic refrigeration apparatus with belt of ferro or paramagnetic material  

DOEpatents

A magnetic refrigerator operating in the 12 to 77 K range utilizes a belt which carries ferromagnetic or paramagnetic material and which is disposed in a loop which passes through the center of a solenoidal magnet to achieve cooling. The magnetic material carried by the belt, which can be blocks in frames of a linked belt, can be a mixture of substances with different Curie temperatures arranged such that the Curie temperatures progressively increase from one edge of the belt to the other. This magnetic refrigerator can be used to cool and liquefy hydrogen or other fluids.

Barclay, J.A.; Stewart, W.F.; Henke, M.D.; Kalash, K.E.

1986-04-03

330

Measurement of viscosity, density, and gas solubility of refrigerant blends in selected synthetic lubricants. Quarterly report, July 1 to September 30, 1993  

SciTech Connect

Liquid/liquid miscibilities of four different 32 ISO VG polyolesters and one alkylbenzene at three concentrations has been determined with five refrigerant blends, including HC-290. A vapor lubricant equilibrium (VLE) viscosity reduction of 32 ISO VG mineral oil with HCFC-22 has been completed. Composite viscosity reduction information by the fractionate components from R-502 in 32 ISO VG mineral oil has been obtained from {minus}10{degrees}C (14{degrees}F) to 125{degrees}C (257{degrees}F) isotherms. Vapor lubricant equilibrium (VLE) viscosity reduction for 32 ISO VG mixed acid polyolester with HFC-134a has also been completed.

Cavestri, R.C. [Imagination Resources, Inc., Dublin, OH (United States)

1993-10-01

331

BNL Refrigerant Overview Presentation to the  

E-print Network

BNL Refrigerant Overview Presentation to the BER and CAC Ed Murphy, PE Chief Engineer / Manager is a heating process. Refrigeration is an engineered "cycle" where the refrigerant is made to evaporate) to the cycle. Refrigerants are the "working fluids" in refrigeration, air conditioning and heat pumping systems

Homes, Christopher C.

332

Evaluation of alternative refrigerant—adsorbent pairs for refrigeration cycles  

Microsoft Academic Search

The refrigerant-adsorbent pairs at present preferred for solid-sorption refrigeration cycles are ammonia-carbon, methanol-carbon, ammonia salts and water-zeolite. Porosity tests have been carried out on a range of alternatives, including R32 and butane, as refrigerants and new monolithic carbon adsorbents. The results of fitting to the Dubinin equation and modelling of cycles based on these pairs are presented. Ammonia is still

R. E. Critoph

1996-01-01

333

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

334

Safety testing of domestic refrigerators using flammable refrigerants  

Microsoft Academic Search

A domestic refrigerator with flammable refrigerant was tested according to the methods specified in the safety Standard, IEC\\/EN 60335-2-24.The tests were all carried out as specified in the Standard. Some of the test specifications were straightforward but some tests ambiguous and gave different results depending on the method used.The method of testing the protection of the refrigeration circuit does not

Andrew Gigiel

2004-01-01

335

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

336

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

337

Compact acoustic refrigerator  

DOEpatents

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

Bennett, Gloria A. (Los Alamos, NM)

1992-01-01

338

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. 12 figs.

Swift, G.W.; Kotsubo, V.Y.

1992-12-22

339

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

340

Reciprocating Magnetic Refrigerator  

NASA Technical Reports Server (NTRS)

Unit cools to 4 K by adiabatic demagnetization. Two porous matrices of paramagnetic material gadolinium/gallium/garnet held in long piston called displacer, machined out of Micarta (phenol formaldehyde polymer). Holes in side of displacer allow heat-exchange fluid to flow to and through matrices within. Piston seals on displacer prevent substantial mixing of fluid in two loops. Magnetic refrigerator provides continuous rather than "one-shot" cooling.

Johnson, D. L.

1985-01-01

341

Downhole pulse tube refrigerators  

Microsoft Academic Search

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

G. Swift; D. Gardner

1997-01-01

342

The APL satellite refrigerator program  

NASA Astrophysics Data System (ADS)

Four satellite refrigerators were built and installed on a satellite to cool gamma ray spectrometers. The p-78-1 satellite, launched on February 24, 1979, was the first satellite to carry gamma ray detectors that were cooled by mechanical refrigerators. Still operating successfully after over 18 months in orbit, this is the first satellite experiment of any kind on which mechanical refrigerators have been operated for longer than a few weeks. This report describes the selection and specifications of the refrigerators as determined by APL and Lockheed, the design and construction of the refrigerators by Philips Laboratories, the design and construction of the motor drive and instrumentation electronics by APL, the APL qualification and acceptance test programs, and the APL laboratory life test program. The orbital performance of the refrigerators is discussed.

Leffel, C. S., Jr.; Vonbriesen, R.

1981-07-01

343

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

344

Vapor pressure of pentafluoroethane and trifluoroiodomethane  

Microsoft Academic Search

Pentafluoroethane (HFC-125) and trifluoroiodomethane (CF3I) are considered as promising refrigerant alternatives, especially as components in mixtures, to replace CFCs or HCFCs. Effective\\u000a uses of HFC-125 and CF3I require that the thermophysical properties be accurately measured. In the present work, vapor pressure data of HFC-125 and\\u000a CF3I have been measured in the temperature range from 292 to 337 K and 288

Chang Zhang; Yuanyuan Duan; Lin Shi; Mingshan Zhu; Lizhong Han

2001-01-01

345

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

346

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

347

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

348

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

349

49 CFR 173.174 - Refrigerating machines.  

Code of Federal Regulations, 2014 CFR

...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

350

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

351

CO 2 and R410A: Two-phase flow visualizations and flow boiling measurements at medium (0.50) reduced pressure  

Microsoft Academic Search

The conversion to more environmentally friendly refrigerants is of prime importance for refrigeration and air-conditioning industries. A first option for the substitution of the fluids which use was banned could be natural refrigerants, such as CO2, or HFC mixtures with low global warming and zero ozone depletion impacts. To determine the heat transfer characteristics during flow boiling of CO2 a

R. Mastrullo; A. W. Mauro; J. R. Thome; G. P. Vanoli

352

Natural refrigerants for refrigeration and air-conditioning systems  

Microsoft Academic Search

In the past, several natural working fluids were used in refrigeration and air-conditioning systems. However, the appearance of CFCs caused a drastic reduction in the utilisation of those fluids. Understanding of the environmental damage of CFCs focused attention on alternative refrigerants. From these, the ones that have minimum (or nil) environmental impact are natural ones. This paper presents a review

S. B. Riffat; C. F. Afonso; A. C. Oliveira; D. A. Reay

1997-01-01

353

Sun synchronous solar refrigeration  

NASA Astrophysics Data System (ADS)

The primary goal of this project was to prototype a complete Sun Synchronous Solar Powered Refrigerator. The key element to the technology is the development of the hermetic motor compressor assembly. The prototype was to be developed to either the stage where Polar Products could receive additional venture capital or to the point whereby Polar could use their own capital to manufacture the systems. Our goal was to construct a prototype which would be the next step to a proven and market ready product. To demonstrate the technology under laboratory conditions was a very minimal goal.

354

Cycling Joule Thomson refrigerator  

NASA Technical Reports Server (NTRS)

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. (inventor)

1983-01-01

355

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

356

He dilution refrigerator  

NASA Astrophysics Data System (ADS)

We describe the preparation of ultracold atomic clouds in a dilution refrigerator. The closed-cycle 3He/4He cryostat was custom made to provide optical access for laser cooling, optical manipulation and detection of atoms. We show that the cryostat meets the requirements for cold atom experiments, specifically in terms of operating a magneto-optical trap, magnetic traps and magnetic transport under ultrahigh vacuum conditions. The presented system is a step toward the creation of a quantum hybrid system combining ultracold atoms and solid-state quantum devices.

Jessen, F.; Knufinke, M.; Bell, S. C.; Vergien, P.; Hattermann, H.; Weiss, P.; Rudolph, M.; Reinschmidt, M.; Meyer, K.; Gaber, T.; Cano, D.; Günther, A.; Bernon, S.; Koelle, D.; Kleiner, R.; Fortágh, J.

2014-09-01

357

Regenerative Sorption Refrigerator  

NASA Technical Reports Server (NTRS)

Two-stage sorption refrigerator achieves increased efficiency via regenerative-heating concept in which waste heat from praseodymium/cerium oxide (PCO) chemisorption compressor runs charcoal/krypton (C/Kr) sorption compressor. Waste heat from each PCO sorption compressor used to power surrounding C/Kr sorption compressor. Flows of heat in two compressor modules controlled by gas-gap thermal switches. Has no wearing moving parts other than extremely long life, room-temperature check valves operating about twice per hour. Virtually no measurable vibration, and has potential operating life of at least ten years.

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

1991-01-01

358

Heat transfer of oil-contaminated HFC134a in a horizontal evaporator  

Microsoft Academic Search

The introduction of chlorine-free refrigerants to the market requires experimental investigations of their behaviour in heat pumps and refrigerators. One particular area of interest is the effect of the new oils on the heat transfer in evaporators and condensers. Oil can either increase or decrease the heat transfer coefficient. This paper presents the results from an experimental investigation of the

K Hambraeus

1995-01-01

359

Semiconductor-based optical refrigerator  

DOEpatents

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

Epstein, Richard I. (Santa Fe, NM); Edwards, Bradley C. (Nekoosa, WI); Sheik-Bahae, Mansoor (Albuquerque, NM)

2002-01-01

360

Magnetocaloric effect and magnetic refrigeration  

Microsoft Academic Search

The phenomenon of the magnetocaloric effect along with recent progress and the future needs in both the characterization and exploration of new magnetic refrigerant materials with respect to their magnetocaloric properties are discussed. Also the recent progress in magnetic refrigerator design is reviewed.

Vitalij K. Pecharsky; Karl A. Gschneidner Jr

1999-01-01

361

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

362

Refrigerator temperature and defrost control  

Microsoft Academic Search

This patent describes a refrigerator having cooling means including an evaporator and a compressor for cooling a refrigerated compartment. The compressor has first and second power terminals and defrost means for heating the evaporator to remove frost. The defrost means has first and second power terminals, and a source of power coupled to first and second power conductors, an electrical

Janke

1987-01-01

363

TRAÇABILITY OF REFRIGERANT LEAK TIGHTNESS  

Microsoft Academic Search

Nowadays leak detection is widely used in various fields such as the automotive and the refri geration industries. In France, the leak tightness of insta llations charged with refrigerants must be controlled period ically by refrigerant detectors, whose sensitivity thresholds are qualified according to several tests described in t he European standard EN 14624. The tests described in the European

Isabelle Morgado; Pierre Otal; Jean-Claude Legras; Denis Clodic

364

Auxiliary outside air refrigerating mechanism  

Microsoft Academic Search

This patent describes an auxiliary outside air refrigerating means for a refrigerated storage room such as a cooler or the like comprising: a heat exchanger having two pairs of inlets and outlets for receiving and re-circulating air supplies from two separate sources and a heat exchange means for transferring heat between the two air supplies without admixing the two air

1986-01-01

365

Auxiliary outside air refrigeration system  

Microsoft Academic Search

An auxiliary outside air refrigeration system is described for cooling an enclosure comprising: a conventional refrigeration system operably disposed to cool the air inside the enclosure; a first airflow passage connecting the interior of the enclosure with a source of ambient air; a motorized outside air fan positioned to move cooler air from the exterior of the enclosure through the

Travers

1993-01-01

366

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

367

Helium dilution refrigeration system  

DOEpatents

A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation is disclosed. 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. 2 figs.

Roach, P.R.; Gray, K.E.

1988-09-13

368

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

E-print Network

M. Bahrami ENSC 461 (S 11) Refrigeration Cycle 1 Refrigeration Cycle Heat flows in direction a low-temperature to high-temperature requires a refrigerator and/or heat pump. Refrigerators and heat of refrigerators and heat pumps is expressed in terms of coefficient of performance (COP): innet H HP innet L R W Q

Bahrami, Majid

369

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.

370

Report of Refrigerated Medication Loss UConn Health  

E-print Network

Report of Refrigerated Medication Loss UConn Health Please complete form & return to John Dempsey Other (Specify): Phone: E-mail: Address: Location of Refrigerator Affected: Date/time refrigerator was out of temperature range: Describe the event below: How long was the refrigerator out of range (hours

Oliver, Douglas L.

371

Solar Powered Intermittent Absorption Refrigeration Unit  

Microsoft Academic Search

The study investigated and evaluated the feasibility of an absorption refrigeration unit on solar power. Its effectiveness as a viable refrigeration option for use in household refrigerators or as an energy efficient and environmentally friendly alternative to conventional refrigerated air conditioning units used in the offices are evaluated. A prototype model that is capable of producing a temperature change in

M. G. Rasul; A. Murphy

372

Modeling supermarket refrigeration energy use and demand  

Microsoft Academic Search

A computer model has been developed that can predict the performance of supermarket refrigeration equipment to within 3% of field test measurements. The Supermarket Refrigeration Energy Use and Demand Model has been used to simulate currently available refrigerants R-12, R-502 and R-22, and is being further developed to address alternative refrigerants. This paper reports that the model is expected to

M. H. Blatt; M. K. Khattar; D. H. Walker

1991-01-01

373

Magnetic refrigeration for maser amplifier cooling  

NASA Technical Reports Server (NTRS)

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

Johnson, D. L.

1982-01-01

374

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

NASA Astrophysics Data System (ADS)

We 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

375

The Quantum Absorption Refrigerator  

E-print Network

A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermodynamics. The third law is quantified, the cooling power J_c vanishes as J_c proportional to T_c^{alpha}, when T_c approach 0, where alpha =d+1 for dissipation by emission and absorption of quanta described by a linear coupling to a thermal bosonic field, where d is the dimension of the bath.

Amikam Levy; Ronnie Kosloff

2011-11-09

376

Multistation refrigeration system  

NASA Technical Reports Server (NTRS)

A closed cycle refrigeration (CCR) system is disclosed for providing cooling at different parts of a maser. The CCR includes a first station for cooling the maser's parts, except the amplifier portion, to 4.5 K. The CCR further includes means with a 3.0 K station for cooling the maser's amplifier to 3.0 K and, thereby, increases the maser's gain and/or bandwith by a significant factor. The means which provide the 3.0 K cooling include a pressure regulator, heat exchangers, an expansion valve, and a vacuum pump, which coact to cause helium, provided from a compressor, to liquefy and thereafter expand so as to vaporize. The heat of vaporization for the helium is provided by the maser amplifier, which is thereby cooled to 3.0 K.

Wiebe, E. R. (inventor)

1978-01-01

377

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. 6 figs.

Crunkleton, J.A.

1992-03-31

378

Solid-Vapor Sorption Refrigeration Systems  

E-print Network

Complex compound sorption reactions are ideally suited for use in refrigeration cycles as an economically viable alternative to CFC refrigerants. Complex compound refrigeration provides a number of energy-saving advantages over present refrigeration... systems beyond the elimination of CFCs. The elimination of moving parts in complex compound equipment lowers maintenance cost. Also, when ammonia is used as the refrigerant, the replacement of the compressor by the complex compound allows for direct...

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

379

Carbon dioxide as a natural refrigerant  

Microsoft Academic Search

In the beginnings of mechanical refrigeration, at the end of the nineteenth century, carbon dioxide was one of the fi rst refrigerants to be used in compression-type refrigerating machines, later gaining widespread application mainly onboard refrigerated ships, but common in other sectors of refrigeration as well. It was only immediately after World War II that CO2<\\/sub> was rapidly eclipsed as

Alberto Cavallini; Claudio Zilio

2007-01-01

380

Field performance of residential refrigerators and combination refrigerator-freezers  

Microsoft Academic Search

Evaluation of the performance of household refrigerators and combination refrigerator-freezers was undertaken in a field experiment to determine the effect of room environment and occupant-usage habits on energy consumption of these appliances. This report presents the results of such an experiment in ten townhouses at Twin Rivers, NJ. One-door manual defrost and two-door frost-free models of various sizes were studied.

Y. L. Chang; R. A. Grot

1979-01-01

381

Using Acid Number as a Leading Indicator of Refrigeration and Air Conditioning System Performance  

SciTech Connect

This report summarizes a literature review to assess the acidity characteristics of the older mineral oil and newer polyolester (POE) refrigeration systems as well as to evaluate acid measuring techniques used in other non-aqueous systems which may be applicable for refrigeration systems. Failure in the older chlorofluorocarbon/hydrochlorofluorocarbon (CFC/HCFC) / mineral oil systems was primarily due to thermal degradation of the refrigerant which resulted in the formation of hydrochloric and hydrofluoric acids. These are strong mineral acids, which can, over time, severely corrode the system metals and lead to the formation of copper plating on iron surfaces. The oil lubricants used in the older systems were relatively stable and were not prone to hydrolytic degradation due to the low solubility of water in oil. The refrigerants in the newer hydrofluorocarbon (HFC)/POE systems are much more thermally stable than the older CFC/HCFC refrigerants and mineral acid formation is negligible. However, acidity is produced in the new systems by hydrolytic decomposition of the POE lubricants with water to produce the parent organic acids and alcohols used to prepare the POE. The individual acids can therefore vary but they are generally C5 to C9 carboxylic acids. Organic acids are much weaker and far less corrosive to metals than the mineral acids from the older systems but they can, over long time periods, react with metals to form carboxylic metal salts. The salts tend to accumulate in narrow areas such as capillary tubes, particularly if residual hydrocarbon processing chemicals are present in the system, which can lead to plugging. The rate of acid production from POEs varies on a number of factors including chemical structure, moisture levels, temperature, acid concentration and metals. The hydrolysis rate of reaction can be reduced by using driers to reduce the free water concentration and by using scavenging chemicals which react with the system acids. Total acid number (TAN), which includes both mineral acids and organic acids, is therefore a useful indicator which can be used to monitor the condition of the system in order to perform remedial maintenance, when required, to prevent system failure. The critical TAN value is the acid level at which remedial action should be taken to prevent the onset of rapid acid formation which can result in system failure. The level of 0.05 mg KOH/g of oil was established for CFC/mineral oil systems based on analysis of 700 used lubricants from operating systems and failed units. There is no consensus within the refrigeration industry as to the critical TAN value for HFC/POE systems, however, the value will be higher than the CFC/mineral oil systems critical TAN value because of the much weaker organic acids produced from POE. A similar study of used POE lubricants should be performed to establish a critical TAN limit for POE systems. Titrimetric analysis per ASTM procedures is the most commonly used method to determine TAN values in lubricants in the refrigeration industry and other industries dealing with lubricating oils. For field measurements, acid test kits are often used since they provide rapid, semi-quantitative TAN results.

Dennis Cartlidge; Hans Schellhase

2003-07-31

382

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

383

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.

384

Short-Cycle Adsorption Refrigerator  

NASA Technical Reports Server (NTRS)

Modular adsorption/Joule-Thomson-effect refrigerator offers fast regeneration; adsorption/desorption cycle time expected to be 1 minute. Pressurized hydrogen generated by bank of compressor modules during heating phase passes through system of check valves and expands in Joule-Thomson junction as it enters refrigeration chamber. Hydrogen absorbs heat from load before it is sucked out by another bank of compressor modules in cooling phase.

Chan, C. K.

1988-01-01

385

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

NASA Astrophysics Data System (ADS)

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 from 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.

Rice, C. Keith; Sand, James R.

386

Non-intrusive refrigerant charge indicator  

DOEpatents

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

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

2005-03-22

387

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

388

Expendable refrigeration control  

SciTech Connect

This patent describes, in a refrigeration system, an apparatus for controlling the opening and closing operation of a liquid flow valve for dispensing fluid fed thereto from a reservoir and using the inherent gas pressure from the reservoir, comprising in combination: (a) a pneumatic piston operated actuator device having a piston side and a rod side, the rod side being operable connected to the flow valve for opening and closing the same; and (b) control means for controlling the operation of the pneumatic actuator device. The control means has a first pneumatic linear timer valve having a cycle time delay and is connected to a gas pressure line of the reservoir. A second pneumatic linear timer valve has an injection time delay and also connected to the gas pressure line of the reservoir, the first and second pneumatic linear timer valves being interconnected through a control valve. A pneumatic actuator control valve is connected to the gas pressure line of the reservoir and to the piston side and rod side of the actuator device for controlling the operation of the actuator device. The first pneumatic linear timer valve is connected to the actuator control valve to operate same after the cycle time delay to cause the actuator device to operate the liquid flow valve to dispense fluid from the reservoir and to further actuate the second pneumatic linear device to initiate the injection time delay and open condition of the liquid flow valve.

Clarke, K.J.; Lamb, G.

1986-12-23

389

Containing CFC refrigerants; The conversion to new refrigerants  

SciTech Connect

This paper reports that the key equipment for air conditioning large commercial buildings is the centrifugal chiller. More than 80,000 of these chillers are in operation today in the U.S. and Canada. Some reputable scientists have concluded, however, that the refrigerant used in most of these chillers, a chlorofluorocarbon (CFC) designated CFC-11, contributes to the degradation of the earth's protective ozone layer when it is emitted, rises into the upper atmosphere, and decomposes. The evidence has spurred state, national and even international action to restrict CFCs. At conferences of the United Nations Environmental Programs, agreement was reached on a worldwide ban of CFC production by the year 2000, with severe limitations on their production before then. These include CFC-11 and CFC-12, both used in some unitary air conditioning systems. What happens now Trane, manufacturer of more than half of the centrifugal chillers operating in the United States and Canada, recommends a choice of programs that are the subject of this article. They permit either safe, continued use of present chillers and refrigerant, or an easy conversion to an ozone-friendly refrigerant in the same chillers and, later, a switch to new chiller equipment totally compatible with the new refrigerant. In the immediate future, it means preventing CFC emission releases into the atmosphere and, eventually, a carefully-prepared switchover to a new refrigerant by properly-engineered equipment modifications.

Siebert, B. (Trane Co., La Crosse, WI (United States))

1991-01-01

390

Top-down Estimation of Emission Strengths of Major Anthropogenic Halocarbons from China Using High-frequency Measurements with HCFC-22/HFC-23 as Tracers  

NASA Astrophysics Data System (ADS)

In this study we present calculations of Chinese emissions of most major anthropogenic halocarbon species, including CFCs (CFC-11, CFC-12), HCFCs (HCFC-22, HCFC-141b, HCFC-142b), HFCs (HFC-134a, HFC-125, HFC-152a, HFC-23, HFC-143a, HFC-32), H-1211, PFCs(CF4, PFC-116, PFC-218) and solvents (CH3Cl, CH2Cl2, CHCl3, CCl4), using data from high-frequency measurements made with a automated GC-MSD instrument (“Medusa”) operated at Gosan station (126°E, 33°N, Jeju Island, Korea) under the Advanced Global Atmospheric Gases Experiment(AGAGE) network. China is one of the top consumers of HCFC-22 in the world, and enhancement of HCFC-22 seem to correlate well with enhancements in most other species, indicative of its wide use. HFC-23 is special in that most its emission occur during HCFC-22 production (1~4% of HCFC-22 production). Considering that China is one of the world’s largest producers of HFC-23, pollution events of HFC-23 indicate influence of specific industrial regions in the vicinity of HCFC-22 production plants. Using measurements during November 2007 ~ December 2008, we analyze pollution occurrence and magnitudes of HCFC-22 data based on the AGAGE pollution algorithm, then use three-dimensional air mass trajectory models to separate pollution events of Chinese origin. From these Chinese pollution events, we analyze the concurrent episodes of pollution in other species to find a enhancement ratio against HCFC-22, which is converted to actual emission rates by multiplying independently calculated values for HCFC-22 emission rates. Similar methodology is used with HFC-23 for a subset of species that show good correlation with both HCFC-22 and HFC-23 enhancements. Our methodology provide a means to assess Chinese emissions of almost all important halocarbons, and the coupled tracer approach provides the means to test the validity of our calculations. Comparing our results to both top-down and bottom-up emissions estimates performed for China as well as global, the importance of Chinese emissions to the global budget can be clearly seen with substantial emissions of CFCs and HCFCs coming from China. While developed countries have been overall faster in adopting HFCs resulting in relatively less total emissions in China, a number of compounds show large Chinese emissions, which may be largely underestimated in current bottom-up studies.

Kim, K.; Kim, J.; Li, S.; Muhle, J.; Stohl, A.; Kim, S.; Lee, G.; Weiss, R. F.

2009-12-01

391

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

392

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

E-print Network

GEA Refrigeration Technologies / GEA Refrigeration Germany GmbH Wolfgang Dietrich / Dr. Ole Fredrich GEA Grasso heat pumps using ammonia ­ the megawatt range #12;GEA Refrigeration Technologies2 efficiency Recommended applications Screw and piston compressor based heat pumps #12;GEA Refrigeration

Oak Ridge National Laboratory

393

IIR Workshop on Refrigerant Charge Reduction in Refrigerating Systems Corresponding author: P. Leblay  

E-print Network

3rd IIR Workshop on Refrigerant Charge Reduction in Refrigerating Systems Corresponding author: P on the refrigerant side and louver fins on the air side. The flat tubes are grouped within a header, to use the heat diameter implies a refrigerant distribution much more penalizing for these exchangers than for round tube

Paris-Sud XI, Université de

394

A review of pulse tube refrigeration  

NASA Technical Reports Server (NTRS)

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

Radebaugh, Ray

1990-01-01

395

A review of absorption refrigeration technologies  

Microsoft Academic Search

This paper provides a literature review on absorption refrigeration technology. A number of research options such as various types of absorption refrigeration systems, research on working fluids, and improvement of absorption processes are discussed.

Pongsid Srikhirin; Satha Aphornratana; Supachart Chungpaibulpatana

2001-01-01

396

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

397

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

398

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...

399

Mixture Experiments  

SciTech Connect

A mixture experiment involves combining two or more components in various proportions or amounts and then measuring one or more responses for the resulting end products. Other factors that affect the response(s), such as process variables and/or the total amount of the mixture, may also be studied in the experiment. A mixture experiment design specifies the combinations of mixture components and other experimental factors (if any) to be studied and the response variable(s) to be measured. Mixture experiment data analyses are then used to achieve the desired goals, which may include (i) understanding the effects of components and other factors on the response(s), (ii) identifying components and other factors with significant and nonsignificant effects on the response(s), (iii) developing models for predicting the response(s) as functions of the mixture components and any other factors, and (iv) developing end-products with desired values and uncertainties of the response(s). Given a mixture experiment problem, a practitioner must consider the possible approaches for designing the experiment and analyzing the data, and then select the approach best suited to the problem. Eight possible approaches include 1) component proportions, 2) mathematically independent variables, 3) slack variable, 4) mixture amount, 5) component amounts, 6) mixture process variable, 7) mixture of mixtures, and 8) multi-factor mixture. The article provides an overview of the mixture experiment designs, models, and data analyses for these approaches.

Piepel, Gregory F.

2007-12-01

400

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

401

Theoretical and experimental investigation of an ammonia–water power and refrigeration thermodynamic cycle  

Microsoft Academic Search

A combined thermal power and cooling cycle proposed by Goswami is under intensive investigation, both theoretically and experimentally. The proposed cycle combines the Rankine and absorption refrigeration cycles, using a binary ammonia–water mixture as the working fluid. This cycle can be used as a bottoming cycle using waste heat from a conventional power cycle or an independent cycle using low

G Tamm; D. Y Goswami; S Lu; A. A Hasan

2004-01-01

402

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

403

Method of operating a transport refrigeration system  

Microsoft Academic Search

A method of enhancing the defrost cycle of a truck refrigeration system which lacks a dedicated prime mover of the internal combustion type, is described comprising the steps of: providing a transport refrigeration system having a first compressor operatively coupled to the engine of the associated truck, a second compressor operatively coupled to an electric motor, and a single refrigeration

1988-01-01

404

Compact heat exchanger for refrigeration systems  

Microsoft Academic Search

In combination with a vapor\\/compression refrigeration system, a defrosting apparatus for receiving mixed phase refrigerant emanating from the system evaporator outlet during system defrost, and transmitting only superheated gaseous refrigerant to the system compressor inlet, is described comprising: a cylindrical metal body having a preselected length, diameter and wall thickness, and top and bottom ends; a metal defrost tube means

1988-01-01

405

IEA ANNEX 26: ADVANCED SUPERMARKET REFRIGERATION SYSTEMS  

Microsoft Academic Search

SUMMARY Present supermarket refrigeration systems require very large refrigerant charges and are heavy electricity consumers. IEA Annex 26 was formed to investigate and help promote use of energy efficient, low-charge refrigeration system designs. Analyses show that advanced systems can reduce energy consumption by over 10% and total equivalent warming impact (TEWI) by as much as 60%. Further, they show that

Van D. Baxter

406

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

407

Absorption refrigeration: cooling with hot water  

Microsoft Academic Search

The absorption cycle is a process by which refrigeration effect is produced through the use of two fluids and some quantity of heat input, rather than electrical input as in the more familiar vapor compression cycle. Both vapor compression and absorption refrigeration cycles accomplish the removal of heat through the evaporation of a refrigerant at a low pressure and the

Rafferty

1984-01-01

408

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

409

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

410

Wheel-type magnetic refrigerator  

DOEpatents

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

Barclay, J.A.

1983-10-11

411

Refrigerator temperature and defrost control  

SciTech Connect

This patent describes a refrigerator having cooling means including an evaporator and a compressor for cooling a refrigerated compartment. The compressor has first and second power terminals and defrost means for heating the evaporator to remove frost. The defrost means has first and second power terminals, and a source of power coupled to first and second power conductors, an electrical control for controlling the application of power to the power terminals of each of the compressor and the defrost means. The control comprises: defrost initiation means for producing a defrost initiation signal upon a determination that the energization of the defrost means is desired.

Janke, D.E.

1987-05-12

412

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.

2012-06-26

413

Wheel-type magnetic refrigerator  

DOEpatents

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

Barclay, J.A.

1982-01-20

414

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

415

Catalyst development for the selective hydrogenolysis of CCl 2F 2 (CFC12) into CH 2F 2 (HFC32)  

Microsoft Academic Search

A good catalyst for the selective hydrogenolysis of waste CCl2F2(CFC-12) into the high added value product CH2F2(HFC-32) has been developed. This catalyst is based on palladium on activated carbon and shows a high selectivity (70–90%) at all conversion levels. It is important to purify the activated carbon support prior to impregnation of the palladium salt. A nitrogen heat pretreatment enhances

E. J. A. X. van de Sandt; A. Wiersma; M. Makkee; H. van Bekkum; J. A. Moulijn

1997-01-01

416

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

417

Magnetic refrigeration using flux compression in superconductors  

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

418

Optimization of Industrial Refrigeration Systems  

E-print Network

A computer program designed to optimize the size of an evaporative condenser in a two-stage industrial refrigeration plant was created. The program sizes both the high-stage and low-stage compressors and an evaporative condenser. Once the initial...

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

419

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

420

Heat Transfer Characteristics of Natural Refrigerant Mixitures(Propane/n-Butane,Propane/i-Butane) in a Counter Flow Type Double-tube Condenser  

NASA Astrophysics Data System (ADS)

This paper deals with the heat exchange performance prediction of a counter flow type double-tube condenser for natural binary refrigerant mixtures composed of Propane/n-Butane or Propane/i-Butane. The local characteristics of heat transfer, mass transfer and pressure drop are calculated using a prediction method developed by the authors. The total pressure drop and the overall heat transfer coefficient are also evaluated on various heat exchange conditions. The calculated results of the natural refrigerant mixtures are compared with those of pure refrigerant HCFC22. In conclusion, natural binary refrigerant mixtures composed of Propane/n-Butane or Propane/i-Butane are appropriate candidates to replace HCFC22 from the viewpoint of heat transfer characteristics.

Koyama, Shigeru; Lee, Sang-Mu; Ishibashi, Akira

421

Vapor pressure of pentafluoroethane and trifluoroiodomethane  

NASA Astrophysics Data System (ADS)

Pentafluoroethane (HFC-125) and trifluoroiodomethane (CF3I) are considered as promising refrigerant alternatives, especially as components in mixtures, to replace CFCs or HCFCs. Effective uses of HFC-125 and CF3I require that the thermophysical properties be accurately measured. In the present work, vapor pressure data of HFC-125 and CF3I have been measured in the temperature range from 292 to 337 K and 288 to 336 K, respectively. Maximum total pressure uncertainty of HFC-125 data is estimated to be within ±1.2 kPa and ±780 Pa for CF3I. Based on the data set and literature values, the vapor pressure equations for HFC-125 and CF3I have been developed. The relative deviation of the equations correlate the measurements within 0.022% for HFC-125 and 0.068% for CF3I, respectively.

Zhang, Chang; Duan, Yuanyuan; Shi, Lin; Zhu, Mingshan; Han, Lizhong

2001-07-01

422

Keeping Cool With Solar-Powered Refrigeration  

NASA Technical Reports Server (NTRS)

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

2003-01-01

423

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

424

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

425

Magnetic Refrigeration: Perfecting the Process  

NSDL National Science Digital Library

Currently, conventional refrigeration technology cyclically pressurizes and depressurizes Chlorofluorocarbons (commonly known as Freon) to provide cooling in modern air conditioners and kitchen refrigerators. One of the main problems with this process is the unavoidable leakage of Freon into the atmosphere, causing ozone depletion and pollution. Additionally, current refrigeration cannot easily reach temperatures below 30 K (-405° F), which are necessary for satellite sensor cooling and hydrogen liquification (for the future fleet of hydrogen-powered cars) without multi-stage cooling that can be grossly inefficient. An exciting and revolutionary alternative to the presently inefficient and environmentally harmful conventional refrigeration is magnetic refrigeration. This technology is based on the magnetocaloric effect of a material (the temperature change of that material due to the alignment of its magnetic spins when subjected to a magnetic field). Prototype magnetic refrigerators use metal alloys and permanent magnets to exploit this effect. A metal alloy is cyclically magnetized and demagnetized to provide powerful and efficient cooling without damage to the earth’s atmosphere. The alloy is placed in the cooling chamber and a strong magnetic field is applied to magnetize the substance, thereby increasing its temperature but cooling the surrounding air in the refrigeration compartment. Then the material is removed from both the cooling chamber and the magnetic field. This allows the atomic spins to return to a disordered state and the stored heat to be released, preparing the material for another cycle of cooling. Magnetic refrigeration is both nondestructive and theoretically more efficient than either vapor expansion or radiant cooling. In order to optimize the cooling effects of a magnetic refrigerator, a metal alloy must be found that exhibits optimal magnetocaloric effects at temperature ranges of interest. A recent publication in Nature (“Hysteresis losses in Gd5Ge2Si2 by addition of iron”, Nature, Volume 429, 24 June 2004, pages 853-857) shows that certain compounds, doped with iron, possess greatly enhanced effects. This project was focused on examining Holmium-Titanium-Germanium (HoTiGe) alloys doped with iron under the prediction they would also possess similar enhancements. Improved cooling potential around 90 K (-298° F) was previously documented by a group of Dutch scientists (“Magnetic-phase transitions and magnetocaloric effects”, Physica B, Volume 319, 15 February 2002, pages 174-192). This summer, we revisited the Dutch research and found large magnetocaloric effects on this particular system at 15 K (-433° F) and 2 K (-456° F) as well. Further, we have identified the specific phase of the alloy that is responsible for these low-temperature magnetocaloric effects, Ho58Ti5Ge36Fe. These results could have a major impact on low-temperature cooling techniques in the future by greatly improving the efficiency of magnetic cooling at low temperatures.

Baumgold, Ben

2005-01-01

426

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.

National Science Foundation GK-12 and Research Experience for Teachers (RET) Programs,

427

Containing CFC refrigerants; The conversion to new refrigerants  

Microsoft Academic Search

This paper reports that the key equipment for air conditioning large commercial buildings is the centrifugal chiller. More than 80,000 of these chillers are in operation today in the U.S. and Canada. Some reputable scientists have concluded, however, that the refrigerant used in most of these chillers, a chlorofluorocarbon (CFC) designated CFC-11, contributes to the degradation of the earth's protective

Siebert

1991-01-01

428

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

429

Chiral mixtures  

NASA Astrophysics Data System (ADS)

An index evaluating the amount of chirality of a mixture of colored random variables is defined. Properties are established. Extreme chiral mixtures are characterized and examples are given. Connections between chirality, Wasserstein distances, and least squares Procrustes methods are pointed out.

Petitjean, Michel

2002-08-01

430

A compact rotating dilution refrigerator  

E-print Network

We describe the design and performance of a new rotating dilution refrigerator that will primarily be used for investigating the dynamics of quantized vortices in superfluid 4He. All equipment required to operate the refrigerator and perform experimental measurements is mounted on two synchronously driven, but mechanically decoupled, rotating carousels. The design allows for relative simplicity of operation and maintenance and occupies a minimal amount of space in the laboratory. Only two connections between the laboratory and rotating frames are required for the transmission of electrical power and helium gas recovery. Measurements on the stability of rotation show that rotation is smooth to around 0.001 rad/s up to angular velocities in excess of 2.5 rad/s. The behavior of a high-Q mechanical resonator during rapid changes in rotation has also been investigated.

Fear, M J; Chorlton, D A; Zmeev, D E; Gillott, S J; Sellers, M C; Richardson, P P; Agrawal, H; Batey, G; Golov, A I

2013-01-01

431

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

432

ASHRAE thermodynamic properties of refrigerants  

SciTech Connect

This edition contains formulations with a higher degree of accuracy for many fluids and covers a wider range of values than formulations used to produce previous ASHRAE tables. Available in either Inch-Pound (I-P) or International System units (SI). Covers thermodynamic property formulations for halocarbons, ammonia, carbon dioxide, hydrocarbons, and cryogenic fluids. Appendix contains ANSI/ASHRAE Standard 34-78. ''Number Designation of Refrigerants.''

Not Available

1986-01-01

433

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

434

Cryogen-free dilution refrigerators  

NASA Astrophysics Data System (ADS)

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

Uhlig, K.

2012-12-01

435

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

436

Magnetocaloric refrigeration near room temperature (invited)  

NASA Astrophysics Data System (ADS)

Modern society relies on readily available refrigeration. The ideal cooling machine would be a compact, solid state, silent and energy-efficient heat pump that does not require maintenance. Magnetic refrigeration has three prominent advantages compared to compressor-based refrigeration. First, there are no harmful gases involved, second it may be built more compact as the working material is a solid and third magnetic refrigerators generate much less noise. Recently, a new class of magnetic refrigerant materials for room-temperature applications was discovered. These new materials have important advantages over existing magnetic coolants: They exhibit a large magnetocaloric effect (MCE) in conjunction with a magnetic phase transition of first order. This MCE is, larger than that of Gd metal, which is used in the demonstration refrigerators built to explore the potential of this evolving technology. In the present review, we compare the different materials considering both scientific aspects and industrial applicability.

Brück, E.; Tegus, O.; Thanh, D. T. C.; Buschow, K. H. J.

2007-03-01

437

TOPICAL REVIEW: Developments in magnetocaloric refrigeration  

NASA Astrophysics Data System (ADS)

Modern society relies on readily available refrigeration. Magnetic refrigeration has three prominent advantages compared with compressor-based refrigeration. First, there are no harmful gases involved; second, it may be built more compactly as the working material is a solid; and third, magnetic refrigerators generate much less noise. Recently a new class of magnetic refrigerant-materials for room-temperature applications was discovered. These new materials have important advantages over existing magnetic coolants: they exhibit a large magnetocaloric effect (MCE) in conjunction with a magnetic phase-transition of first order. This MCE is larger than that of Gd metal, which is used in the demonstration refrigerators built to explore the potential of this evolving technology. In the present review we compare the different materials considering both scientific aspects and industrial applicability. Because fundamental aspects of MCE are not so widely discussed, we also give some theoretical considerations.

Brück, Ekkes

2005-12-01

438

High-Performance, Low Environmental Impact Refrigerants  

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

439

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

440

Analysis of Secondary-Loop Refrigeration Systems Using Carbon Dioxide as a Volatile Secondary Refrigerant  

Microsoft Academic Search

A secondary-loop refrigeration system, using ammonia in the primary-loop and carbon dioxide as a volatile secondary refrigerant, was investigated as an alternative system for supermarkets. Ammonia and carbon dioxide are naturally occurring substances which have zero ozone depletion and zero effective global warming potential. The use of these natural refrigerants provides a long-term solution to environmental problems associated with refrigeration.

Scott W. Inlow; Eckhard A. Groll

1996-01-01

441

Optimization of characteristics of refrigerating machine operating with recharging of compressor cylinder with refrigerant  

Microsoft Academic Search

The results of scientific and technical research for improving the characteristics of small refrigerating machines (SRM) by\\u000a adapting them to effective natural refrigerants (R600a and R600) are reported. A method, which consists in recharging (supplementary\\u000a charging) of the compressor cylinder with a refrigerant in a Voorhees refrigerating machine, has been proposed for reducing\\u000a losses in the compressor. The results of

G. K. Lavrenchenko

2008-01-01

442

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

443

Heat Pipe Applications in Sorption Refrigerators  

Microsoft Academic Search

\\u000a Some sorption refrigeration machines (sorption technologies) developed in Belarus are presented in this paper with emphasises\\u000a on different heat pipes application: conventional heat pipes, heat pipe panels, loop heat pipes, vapour-dynamic thermosyphons,\\u000a etc. Heat pipes are very flexible systems with regards to the effective thermal control. They can easily be implemented inside\\u000a sorption refrigerators and other types of refrigerators [1].

L. L. Vasiliev; A. G. Kulakov

444

Solar refrigeration - Study of dry absorption  

NASA Astrophysics Data System (ADS)

Because the severe conditions imposed by ambient temperatures on solar refrigeration equipment in the tropics limit the choice of an absorption system, the thermokinetic characteristics of a calcium chloride/ammonia absorption cycle were examined. The refrigeration equipment employed works in two stages: vaporization and condensation of ammonia during the day and regeneration during the night. It is concluded that the refrigeration aparatus will be too cumbersome to serve as a portable system.

Flechon, J.; Machizaud, F.

445

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 (GR(SO4)), magnetite (Fe(3)O(4)), 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

446

Experimental studies of isobutane (R600a) as the refrigerant in domestic refrigeration system  

Microsoft Academic Search

This paper presents an experimental study on the performance of a domestic vapor-compression refrigeration system with isobutane (R600a) as the refrigerant. The input power of the compressor varied between 230 and 300 W, while the amount of the charged refrigerant was about 150 g. The expansion and heat transfer components of the system were capillary tubes and plate heat exchangers,

Y. S Lee; C. C Su

2002-01-01

447

Materials compatibility and lubricants research on CFC-refrigerant substitutes: Thermophysical properties  

SciTech Connect

Numerous fluids have been identified as promising alternative refrigerants, but much of the information needed to predict their behavior as pure fluids and as components in mixtures does not exist. In particular, reliable thermophysical properties data and models are needed to predict the performance of the new refrigerants in heating and cooling equipment, and to design and optimize equipment to be reliable and energy efficient. The objective of this project is to provide highly accurate, selected thermophysical properties data for Refrigerants 32, 123, 124, and 125, and to use these data to fit simple and complex equations of state and detailed transport property models. The new data will fill in the gaps in existing data sets and resolve the problems and uncertainties that exist in and between the data sets. This report describes the progress made during the first quarter of this fifteen-month project, which was initiated in late January, 1992.

Kayser, R.F. (National Inst. of Standards and Technology, Gaithersburg, MD (United States). Thermophysics Div.)

1992-04-01

448

University of Connecticut Daily Temperature Log Specimen Refrigerator Log  

E-print Network

University of Connecticut Daily Temperature Log ­ Specimen Refrigerator Log Month / Year Clinical ___ Fac. Mgmt. Resolution: 31 ___ Fac. Mgmt. Resolution: If the refrigerator temperature falls out refrigerator. This record must be kept for one year and then destroyed per State requirement

Oliver, Douglas L.

449

46 CFR 58.20-15 - Installation of refrigerating machinery.  

Code of Federal Regulations, 2014 CFR

...ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Refrigeration Machinery § 58.20-15 Installation of refrigerating...control device located outside the compartment. (c) All refrigeration compressor spaces shall be effectively ventilated and...

2014-10-01

450

46 CFR 130.230 - Protection from refrigerants.  

Code of Federal Regulations, 2013 CFR

...230 Protection from refrigerants. (a) For each refrigeration system that exceeds 0.6 cubic meters (20 cubic...stowed convenient to, but outside, the space containing the refrigeration equipment. (c) A complete recharge in the form...

2013-10-01

451

16 Heat Transfer and Air Flow in a Domestic Refrigerator  

E-print Network

445 16 Heat Transfer and Air Flow in a Domestic Refrigerator Onrawee Laguerre UMR Génie Industriel...............................................447 16.2.1 Studies in Domestic Refrigerators...................................................................................... 451 16.3 Cold Production System in Domestic Refrigerators

Paris-Sud XI, Université de

452

46 CFR 130.230 - Protection from refrigerants.  

Code of Federal Regulations, 2014 CFR

...230 Protection from refrigerants. (a) For each refrigeration system that exceeds 0.6 cubic meters (20 cubic...stowed convenient to, but outside, the space containing the refrigeration equipment. (c) A complete recharge in the form...

2014-10-01

453

46 CFR 130.230 - Protection from refrigerants.  

Code of Federal Regulations, 2011 CFR

...230 Protection from refrigerants. (a) For each refrigeration system that exceeds 0.6 cubic meters (20 cubic...stowed convenient to, but outside, the space containing the refrigeration equipment. (c) A complete recharge in the form...

2011-10-01

454

46 CFR 130.230 - Protection from refrigerants.  

Code of Federal Regulations, 2012 CFR

...230 Protection from refrigerants. (a) For each refrigeration system that exceeds 0.6 cubic meters (20 cubic...stowed convenient to, but outside, the space containing the refrigeration equipment. (c) A complete recharge in the form...

2012-10-01

455

46 CFR 58.20-20 - Refrigeration piping.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Refrigeration piping. 58.20-20 Section 58.20-20 Shipping...Refrigeration Machinery § 58.20-20 Refrigeration piping. (a) All piping materials shall be suitable for handling...

2014-10-01

456

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...

457

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

Code of Federal Regulations, 2014 CFR

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

2014-10-01

458

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

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide, refrigerated liquid. 179...and 120) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must...

2013-10-01

459

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Carbon dioxide, refrigerated liquid. 179...and 120) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must...

2010-10-01

460

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide, refrigerated liquid. 179...and 120) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must...

2012-10-01

461

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

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide, refrigerated liquid. 179...and 120) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must...

2011-10-01

462

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

Code of Federal Regulations, 2014 CFR

...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

463

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 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...

2012-10-01

464

Ideal-gas specific heat and second virial coefficient of HFC-125 based on sound-velocity measurements  

NASA Astrophysics Data System (ADS)

The sound velocity in gaseous pentafluoroethane (HFC-125, CF3CHF2) has been measured by means of a spherical acoustic resonator, Seventy-two sound-velocity values were measured with an uncertainty of ±0.01% at temperatures from 273 to 343 K and pressures from 101 to 250 kPa. The ideal-gas specific heats and the second acoustic-virial coefficients have been determined on the basis of the Sound-velocity measurements. The second virial coefficients calculated from the present sound-velocity measurements agree with literature values which were determined from PVT measurements by means of a Burnett method.

Hozumi, T.; Sato, H.; Watanabe, K.

1996-05-01

465

REVIEW OF SUPERCONDUCTING MAGNETOMETERS AND CRYOGENIC REFRIGERATION TECHNIQUES  

E-print Network

3. REVIEW OF SUPERCONDUCTING MAGNETOMETERS AND CRYOGENIC REFRIGERATION TECHNIQUES By W. S. GOREE and handling problems may be encountered in field applications. Closed cycle miniature refrigerators could make

Boyer, Edmond

466

46 CFR 128.410 - Ship's service refrigeration systems.  

Code of Federal Regulations, 2010 CFR

... Ship's service refrigeration systems. 128...SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS... Ship's service refrigeration systems. No self-contained unit either for air-conditioning or for...

2010-10-01

467

46 CFR 128.410 - Ship's service refrigeration systems.  

Code of Federal Regulations, 2011 CFR

... Ship's service refrigeration systems. 128...SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS... Ship's service refrigeration systems. No self-contained unit either for air-conditioning or for...

2011-10-01

468

Prediction of Dangerous Time in Case Hydrocarbon Refrigerant Leaks into Household Refrigerator Cabinet  

NASA Astrophysics Data System (ADS)

Hydrocarbon refrigerators are now on sale in European countries. However, hydrocarbons are flammable. A common claim is that concentration of hydrocarbon in the refrigerator could exceed the lower explosive limit by a sudden leak and then a spark ignites a flame causing overpressure. There is the need of the studies on potential risks originated from the use of flammable refrigerants. Thus, the flow rate of the fresh air into the refrigerator cabinet has been defined experimentally, and the spatial average concentration in the refrigerator cabinet has been analyzed theoretically to predict the dangerous time in excess of the lower explosive limit.

Meguro, Takatoshi; Kaji, Nobufuji; Miyake, Kunihiro

469

Vapour–liquid equilibrium measurements and correlation for the pentafluoroethane (R125) + n-butane (R600) system  

Microsoft Academic Search

Mixtures formed by hydrocarbons (HC) and hydrofluorocarbons (HFC) are considered promising possible substitutes for the chlorinated refrigerants and for HFC with high global warming potential (GWP). Following our studies on this kind of systems, vapour–liquid equilibria (VLE) experimental data for the R125+R600 system were measured at temperatures 278.15 and 298.15K by means of a static analytical method, with preliminary recirculation

L. Fedele; S. Bobbo; R. Camporese; R. Stryjek

2005-01-01

470

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

471

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

472

Feasibility Study of an Automotive Thermoacoustic Refrigerator  

Microsoft Academic Search

Concerns regarding the environmental impact associated with the use of current vapour-compression refrigeration systems in automobiles have led to the investigation of alternative 'green' technologies. Thermoacoustic refrigera- tion, an emerging 'green' technology based upon the purposeful use of high-pressure sound waves to provide cooling, is the most promising replacement investigated so far. Thermoacoustic refrigerators use environmentally benign gases, are relatively

Luke Zoontjens; Carl Howard; Anthony Zander; Ben Cazzolato

2005-01-01

473

Bypass and monitoring circuit for refrigeration system  

Microsoft Academic Search

A bypass and monitoring circuit is described for use with a refrigeration system having means to sense a need to initiate a defrost cycle and means to reset the defrost cycle upon sensing the defrosting of the refrigeration system. The circuit comprises: first means to sense whether the duration of each defrost cycle exceeds a certain period; and second means,

G. Kyzer; J. Smollon

1987-01-01

474

Your Mileage May Vary. [Refrigerator Energy Guide  

Microsoft Academic Search

The annual energy costs of operating a refrigerator (for several energy prices) and an indication of the range for similar units appear on the yellow Energy Guide. These figures are the result of a standardized test performed by the manufacturer as required by the Federal trade Commission (FTC) for all refrigerators sold in the United States. The manufacturer must test

Heinemeier

2009-01-01

475

Absorption refrigeration and heat pump system  

Microsoft Academic Search

A method of defrosting a multiple effect absorption refrigeration and heating system having means for switching a refrigerant flow from a second heat exchanger operating as a condenser in the heating mode to a first heat exchanger operating as an evaporator in the heating mode, with the first heat exchanger in heat transfer relationship with an ambient fluid and the

E. M. Purvis; E. A. Jr. Reid; F. B. Cook; S. P. Cremean

1988-01-01

476

Energy saving change of phase refrigeration system  

Microsoft Academic Search

An improved change of phase refrigeration system is disclosed utilizing low compressor head pressures to maximize compressor efficiency, employing a relatively low temperature cooling medium to cool refrigerant gases, using a metering device which is operable at a relatively low pressure differential to feed condensate to the evaporator coil and providing additional controls to temporarily increase head pressure and thus

A. Perez; E. E. Bowman

1978-01-01

477

Asset Management Equipment Disposal Form -Refrigerant Recovery  

E-print Network

Asset Management Equipment Disposal Form - Refrigerant Recovery Safe Disposal Requirements Under EPA's rule, equipment that is typically dismantled on site before disposal (e.g., retail food the refrigerant recovered in accordance with EPA's requirements for servicing. However, equipment that typically

Sin, Peter

478

Theoretical Evaluation of Carbon Dioxide Refrigeration Cycle  

Microsoft Academic Search

Concerns of ozone depletion and global warming call for investigation of natural refrigerants. In this study the performance potential of the carbon dioxide refrigeration cycle is investigated theoretically. For this purpose, two cycle simulation models were developed. One is an Evans-Perkins cycle model for R-22, and the other is a transcritical cycle model for CO2. By using these models, the

Yunho Hwang; Reinhard Radermacher

1998-01-01

479

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

480

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

481

Proceedings: commercial refrigeration research workshop. Summary  

Microsoft Academic Search

The purpose of this workshop was to identify the state-of-the-art and determine research needs for improving energy use and demand in commercial refrigeration applications. Workshop attendees included research and development, technical operations and marketing people from manufacturers of supermarket refrigeration, space conditioning, and energy management systems equipment, and from supermarket chains and electric utilities. Presentations were given on best current

Blatt

1984-01-01

482

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...

483

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...

484

Sorption compressor/mechanical expander hybrid refrigeration  

NASA Technical Reports Server (NTRS)

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

Jones, J. A.; Britcliffe, M.

1987-01-01

485

Permanent magnet array for the magnetic refrigerator  

NASA Astrophysics Data System (ADS)

Recent research into the development of magnetic refrigeration (MR) operating at room temperature has shown that it can provide a reliable, energy-efficient cooling system. To enhance the cooling power of the magnetic refrigerator, it is required to use a magnetic refrigerant material with large magnetocaloric effect (MCE) at the appropriate temperature. Most advanced magnetic refrigerant materials show largest MCE at high applied magnetic fields generated by a superconducting magnet. For application of MCE to air conditioners or household refrigerators, it is essential to develop a permanent magnet array to form a compact, strong, and energy-efficient magnetic field generator. Generating a magnetic field well above the remanence of a permanent magnet material is hard to achieve through conventional designs. A permanent magnet array based on a hollow cylindrical flux source is found to provide an appropriate geometry and magnetic field strength for MR applications.

Lee, S. J.; Kenkel, J. M.; Pecharsky, V. K.; Jiles, D. C.

2002-05-01

486

Compatibility of refrigerants and lubricants with elastomers  

SciTech Connect

Information contained in this report is designed to assist the air-conditioning and