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Development of Cladding Materials for Evacuated Panel Superinsulation

Description: This Cooperative Research and Development Agreement (CRADA) was among E.I. DuPont de Nemours and Company, VacuPanel, Inc., and Lockheed Martin Energy Research Corp. Evacuated panel superinsulations have thermal resistivities (R) substantially above that of conventional existing insulation without the environmental problems of some insulations such as foam insulations blown with Chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs).
Date: November 1, 1999
Creator: Wilkes, K.E.; Weaver, F.J.; Cumberbatch, G.M.; Begnoche, B.; Brodie, V.; Lamb, W. et al.
Partner: UNT Libraries Government Documents Department

Boiling Heat Transfer of Refrigerant R-113 in a Small-Diameter, Horizontal Tube

Description: Results of a study of boiling heat transfer from refrigerant R-113 in a small-diameter (2.92-mm) tube are reported. Local heat transfer coefficients over a range of heat fluxes, mass fluxes, and equilibrium mass qualities were measured. The measured coefficients were used to evaluate eight different heat transfer correlations, some of which have been developed specifically for refrigerants. High heat fluxes and low flow rates are inherent in small channels, and this combination results in high boiling numbers. The high boiling number of the collected data shows that the nucleation mechanism was dominant. As a result, the two-phase correlations that predicted this dominance also predicted the data best if they also properly modeled the physical parameters. The correlations of Lazarek and Black and of Shah, as modified in this study, predicted the data very well. It is also shown that a simple form, suggested by Stephan and Abdelsalam for nucleate boiling, correlates the data equally well. This study is part of a research program in multiphase flow and heat transfer, with the overall objective of developing validated design correlations and predictive methods that will facilitate the design and optimization of compact heat exchangers for use with environmentally acceptable alternatives for chlorofluorocarbon (CFC) refrigerants and refrigerant mixtures.
Date: January 1992
Creator: Wambsganss, M. W.; France, D. M.; Jendrzejczyk, J. A. & Tran, T. N.
Partner: UNT Libraries Government Documents Department

Lean flammability limit as a fundamental refrigerant property. Phase 1, Interim technical report, 1 October 1994--31 March 1995

Description: Due to the ozone-depleting effects of commonly used chlorofluorocarbon refrigerants, safe environmentally-friendly replacements must be found. HFC-32 (CH{sub 2}F{sub 2}) and other hydrochlorofluorocarbons are potential candidates; however, in contrast with the CFCs, many of these compounds are flammable. Testing the flammability limits of these hydrochlorofluorocarbons using traditional ASTM E-681 methods has produced a range of limits depending upon the vessel and ignition source used. This project demonstrates the feasibility of defining a fundamental flammability limit of HFC-32, that occurs at the limit of a zero strain rate and is independent of ignition source. Using a counterflow twin-flame burner to define extinction points for different strain rates, an extrapolation to zero strain rate is performed. Using this technique, preliminary results on the lean flammability limit of HFC-32 and the critical flammability ratio of HFC-125 (C{sub 2}HF{sub 5}) in ETC-32 are reported.
Date: March 31, 1995
Creator: Womeldorf, C.; King, M. & Grosshandler, W.
Partner: UNT Libraries Government Documents Department

An evaluation of alternative cleaning methods for removing an organic contaminant from a stainless steel part

Description: As of December 1995, the manufacture of Freon, along with many other chlorofluorocarbons (CFCs), was prohibited by the Clean Air Act of 1990 (CAA). The ban of CFC solvents has forced manufacturers across the country to search for alternative metal cleaning techniques. The objective of this study was to develop a thorough, scientific based approach for resolving one specific manufacturer`s problem of removing organic contamination from a stainless steel part. This objective was accomplished with an approach that involved: (1) defining the problem, (2) identifying the process constraints, (3) researching alternate cleaning methods, (4) researching applicable government regulations, (5) performing a scientific evaluation and (6) drawing conclusions.
Date: August 1, 1996
Creator: Boyd, J.L.
Partner: UNT Libraries Government Documents Department

Recent development in green buildings

Description: Because of the environmental concerns about some materials used in buildings, particularly chlorofluorocarbon (CFC) fluids used as the blowing agent for insulation materials and as refrigerants used in the air conditioning systems have led to a search for environmentally safe alternatives. For insulation materials, new non-CFC blowing agents are still under development. However, the old insulation materials in the buildings will stay because they do not pose any further environmental damage. It is a different story for refrigerants used in air conditioning systems. This study reports that the change-over from CFC to non-CFC refrigerants in the existing and future air conditioning equipment could be a chance not only to take care of the environmental concerns, but to save energy as well. Alternative air conditioning technologies, such as the desiccant dehumidification and absorption systems, and the potential of some natural substances, such as carbon dioxide, as the future refrigerants are also discussed.
Date: December 31, 1996
Creator: Mei, V.C.
Partner: UNT Libraries Government Documents Department

Thermophysical properties of HCFC alternatives. Quarterly report, 1 April 1996--30 June 1996

Description: Numerous fluids and fluid mixtures have been identified as promising alternatives to the HCFC refrigerants, but, for many of them, reliable thermodynamic data do not exist. In particular, reliable thermodynamic 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 measure, with high accuracy, selected thermodynamic properties data for two pure refrigerants and nine refrigerant blends; these data will be used to fit equations of state and other property models which can be used in equipment design. The new data will fill in gaps in the existing data and resolve problems and differences that exist in and between existing data sets. Most of the studied fluids and blends are potential replacements for HCFC-22 and/or R502; in addition, one pure fluid and one blend are potential replacements for CFC-13 in low temperature refrigeration applications.
Date: July 1, 1996
Creator: Haynes, W.M.
Partner: UNT Libraries Government Documents Department

Materials compatibility and lubricants research on CFC-refrigerant substitutes. Quarterly report, October 1, 1995--December 31, 1995

Description: The quarterly status report for the Materials Compatibility and Lubricants Research Program is presented. Objectives for 1 October 1995--31 December 1995 include completion of contract negotiations for Study of Foaming Characteristics project, and finalizing Phase IV and Phase V projects.
Date: February 1, 1996
Creator: Szymurski, S.R.
Partner: UNT Libraries Government Documents Department

A purge-and-trap capillary column gas chromatographic method for the measurement of halocarbons in water and air

Description: This report describes an automated, accurate, precise and sensitive capillary column purge- and -trap method capable of quantifying CFC-12, CFC-11, CFC-113, CH{sub 3}CCL{sub 3}, and CCL{sub 4} during a single chromatographic analysis in either water or gas phase samples.
Date: June 1, 1996
Creator: Happell, J.D.; Wallace, D.W.R.; Wills, K.D.; Wilke, R.J. & Neill, C.C.
Partner: UNT Libraries Government Documents Department

Thermophysical properties of HCFC alternatives. Quarterly report, October 1, 1994--December 31, 1994

Description: Numerous fluids and fluid mixtures have been identified as promising alternatives to the HCFC refrigerants, but, for many of them, reliable thermodynamic data do not exist. In particular, reliable thermodynamic 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 measure, with high accuracy, selected thermodynamic properties data for two pure refrigerants and nine refrigerant blends; these data will be used to fit equations of state and other property models which can be used in equipment design. The new data will fill in gaps in the existing data and resolve problems and differences that exist in and between existing data sets. Most of the studied fluids and blends are potential replacements for HCFC-22 and/or R502; in addition, one pure fluid and one blend are potential replacements for CFC-13 in low temperature refrigeration applications.
Date: January 1, 1995
Creator: Haynes, W.M.
Partner: UNT Libraries Government Documents Department

Thermophysical properties of HCFC alternatives. Quarterly report, 1 January 1996--31 March 1996

Description: Numerous fluids and fluid mixtures have been identified as promising alternatives to the HCFC refrigerants, but, for many of them, reliable thermodynamic data do not exist. In particular, reliable thermodynamic 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 measure, with high accuracy, selected thermodynamic properties data for two pure refrigerants and nine refrigerant blends; these data will be used to fit equations of state and other property models which can be used in equipment design. The new data will fill in gaps in the existing data and resolve problems and differences that exist in and between existing data sets. Most of the studied fluids and blends are potential replacements for HCFC-22 and/or R502; in addition, one pure fluid and one blend are potential replacements for CFC-13 in low temperature refrigeration applications.
Date: April 1, 1996
Creator: Haynes, W.M.
Partner: UNT Libraries Government Documents Department

Evaluation of HFC-245ca for commercial use in low pressure chillers. Final report, Volume II: Chiller test data

Description: The data presented here were taken under Trane Laboratory Test Order 23127 between May and October 1995. The chiller was a 200 nominal ton three stage direct drive centrifugal chiller with two economizers. Three sets of impellers, three refrigerants and two oils were tested in the chiller according to the following matrix. Trane 22 is a mineral oil and Solest 68 is a polyolester oil. Runs 1 through 6 were to optimize the refrigerant charge using CFC-11. This was determined to be 360 lbm (163.3 Kg) and this value was used for all three refrigerants. The chiller takes a charge of six gallons of oil (22.7 liters). These data which follow are divided into Large Impeller, Medium Impeller and Small Impeller sets further subdivided by Imperial and Metric presentation. The data were taken in Imperial Units. These data are presented in four-page sets. Page 1 shows the reduced chiller test data. Page 2 shows some supporting calculations by curve fit, such as motor efficiency and motor speed. Pages 3 and 4 show the raw data as delivered by the laboratory. All following four-page sets are repetition of the form but for successive test runs.
Date: March 1, 1996
Creator: Keuper, E.F.
Partner: UNT Libraries Government Documents Department

Vapor-Explosion Experiments with Subcooled Freon

Description: Vapor-explosion experiments were conducted in a well-wetted Freon-22 and mineral-oil system in which the initial temperature of both the Freon and the mineral oil were varied over a wide range. These experiments were specifically conducted to investigate the importance of interface temperature in determining the explosive behavior of a given system. The results clearly demonstrate that the interface temperature developed upon intimate liquid-liquid contact is a valid characterization of the explosive potential of a given system.
Date: June 1977
Creator: Henry, Robert E. & McUmber, Louis M.
Partner: UNT Libraries Government Documents Department

Occurrence of Critical Heat Flux During Blowdown with Flow Reversal

Description: A small-scale experiment using Freon-11 at 130 degrees F (54.4 degrees C) and 65 psia (0.45 MPa) in a well-instrumented, transparent annular test section was used to study the occurrence of critical heat flux (CHF) during blow-down with flow reversal. The inner stainless steel tube of the annulus was uniformly heated over its 61-cm length. Inlet and exit void fractions were measured by a capacitance technique. Flow-regime transition was observed with high-speed photography. A 1-hr contact time between Freon-11 and nitrogen at 130 degrees F (54.4 degrees C) and 60 psig (0.517 MPa) was found to greatly affect the steady-state sub-cooled-boiling initial conditions. Delay in bubble growth was observed in adiabatic blow-down runs. This was caused by the conditions of thermodynamic non-equilibrium required for the unstable bubble growth. For the diabatic runs, equilibrium was more closely approached in the test section during the early phase of blow-down.
Date: January 1977
Creator: Leung, J. C. M.
Partner: UNT Libraries Government Documents Department

Compatibility of refrigerants and lubricants with motor materials under retrofit conditions

Description: Compatibility tests were conducted on motor materials to determine whether exposure to the original refrigerant/mineral oil would affect compatibility of the motor materials with the alternative refrigerant/lubricant after retrofit. The motor materials were exposed at elevated temperature to the original refrigerant and mineral oil for 500 hours, followed by exposure to the alternative refrigerant and lubricant for 500 hours. Motor materials exposed to the alternative refrigerant and lubricant (after an initial exposure to the original refrigerant and mineral oil) appeared to be compatible with the alternative refrigerant and lubricant. The only concern was delamination and blistering of the sheet insulation containing Nomex, especially after removal of absorbed refrigerant at high temperature. This was attributed to incompatibility of the adhesive and not to the Nomex itself. Embrittlement of the polyethylene terephthalate (PET) sheet and sleeving insulations was initially observed, but subsequent tests under extremely dry conditions showed that embrittlement of the PET materials was attributed to moisture present during the exposure.
Date: December 1, 1995
Creator: Doerr, R.G. & Waite, T.D.
Partner: UNT Libraries Government Documents Department

Experimental analysis of a window air conditioner with R-22 and zeotropic mixture of R-32/125/134a

Description: This study is the result of the cooperative research and development agreement (CRADA) between Oak Ridge National Laboratory and E.I. Du Pont De Nemours and Company, Inc., (CRADA No. 92-0161) for testing the use of heat exchangers as the evaporator and condenser in an air-conditioning rig. Heat exchangers at typical realistic operating conditions were tested with R-22 and with its potential replacement, a ternary mixture of R-32(30%)/R-125(10%)/R-134a(60%). A test rig was built that provided for operation of the low-temperature exchanger (evaporator) with flooded coils. The test results indicated that the performance of the evaporator heat exchanger using ternary mixture, in terms of cooling capacity, would be around 7.4% less than the performance using R-22. The cooling capacity for both refrigerants improved with flooded evaporator operation by 8.6% for R-22 and by 15% for ternary mixture. Compared with R-22 operation, operation with ternary mixture results in slightly higher compressor discharge pressure, lower compressor discharge temperature, slightly lower compressor power consumption, and a higher compressor high-low pressure ratio. Temperature glide for ternary mixture, for both evaporator and condenser, was clearly evident, but not as pronounced as expected because of the pressure drop (and thus the temperature drop) along the coils. Further improvement of the performance of ternary mixture is possible if the evaporator is arranged in a counter-cross-flow configuration to take advantage of the temperature glide. Current evaporator designs are mostly concurrent-cross-flow, which is more appropriate for single-component refrigerants or azeotropic refrigerant mixtures.
Date: August 1, 1995
Creator: Mei, V.C.; Chen, F.C.; Carlstedt, J. & Hallden, D.
Partner: UNT Libraries Government Documents Department

Experimental comparison of a nearly azeotropic refrigerant blend and R-22 in a water-to-water laboratory test rig

Description: A newly developed, non-ozone-depleting refrigerant blend containing a fluoroiodocarbon compound was compared with R-22 in a laboratory-scale, water-to-water refrigeration cycle test loop. The loop is equipped with a coaxial tube-in-tube condenser, a baffled shell-in-tube evaporator, and a variable-speed compressor. The blend and R-22 were tested at saturated evaporator temperature conditions of about {minus}10 F to {minus}20 F and saturated condenser temperature conditions from about 80--100 F. The compressor speed was varied such that evaporator (cooling) capacity was held constant at approximately the same value for both refrigerants for each test condition. To maintain equal capacity, results showed the compressor speed for the blend to be at least 53% greater than that for R-22. Measured system efficiency with the blend was at least 25% better than for R-22 for near equal operating temperature and capacity conditions. When allowing for maximum impact of the experimental uncertainties, the minimum COP improvement observed for the blend was about 10%. Ideal cycle calculations using the best available property estimates for the blend and the compressor efficiencies observed during the tests also suggested a 10% improvement for the blend over R-22 (almost all due to better isentropic efficiency of the compressor with the blend). Better thermodynamic property data are needed for the blend and further investigations are needed to fully assess its potential for refrigeration equipment applications.
Date: November 1, 1998
Creator: Baxter, V.D.; Chen, D.T.; Linkous, R.L. & Nimitz, J.
Partner: UNT Libraries Government Documents Department

Study of lubricant circulation in HVAC systems

Description: This program was aimed at understanding refrigerant/lubricant circulation issues, developing test data and approximate models that can predict operating regimes where good oil management can be assured. A dynamic test facility was constructed and used to examine oil return under varying system operating conditions. The development of industry guidelines for system reliability in using the new refrigerant blends was a goal of this program. To validate the guidelines, techniques and predictions, this dynamic test facility was used to obtain data to compare to the analytical predictions. The overall program approach undertaken to meet this objective was: (1) to identify poor oil return scenarios and, therefore, the worst case oil return parameters for conventional residential HVAC systems using HCFC-22 and mineral oils, in terms of compressor, suction and exhaust line vapor velocity, and refrigerant viscosity requirements; (2) design and instrument a test apparatus that simulates such conditions, as well as those that might be achieved with HFC and POE mixtures and HFCs and mineral oils; (3) conduct tests with the range of baseline refrigerants and lubricant mixtures to provide experimental data; and (4) prepare, present and interpret the test data to provide an expanded understanding of the phenomena required for good oil circulation in split-system heat pump systems. To convert this general approach into the program specifics, three major tasks were defined and pursued. These are described briefly here and in greater detail in the report body as Task 1, Task 2, and Task 3. The report prepared for ARTI as part of the MCLR Project Number 665-53100 is described in Volumes 1 and 2, ``Study of Lubricant Circulation in the HVAC Systems,`` October 1996, from the same authors as this publication. This record consists of the overheads used in the presentation.
Date: February 1, 1997
Creator: Biancardi, F.; Sienel, T.; Pandy, D. & Michels, H.
Partner: UNT Libraries Government Documents Department

Emissions of greenhouse gases in the United States 1995

Description: This is the fourth Energy Information Administration (EIA) annual report on US emissions of greenhouse gases. This report presents estimates of US anthropogenic (human-caused) emissions of carbon dioxide, methane, nitrous oxide, and several other greenhouse gases for 1988 through 1994. Estimates of 1995 carbon dioxide, nitrous oxide, and halocarbon emissions are also provided, although complete 1995 estimates for methane are not yet available. Emissions of carbon dioxide increased by 1.9% from 1993 to 1994 and by an additional 0.8% from 1994 to 1995. Most carbon dioxide emissions are caused by the burning of fossil fuels for energy consumption, which is strongly related to economic growth, energy prices, and weather. The US economy grew rapidly in 1994 and slowed in 1995. Estimated emissions of methane increased slightly in 1994, as a result of a rise in emissions from energy and agricultural sources. Estimated nitrous oxide emissions increased by 1.8% in 1995, primarily due to increased use of nitrogen fertilizers and higher output of chemicals linked to nitrous oxide emissions. Estimated emissions of hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), which are known to contribute to global warming, increased by nearly 11% in 1995, primarily as a result of increasing substitution for chlorofluorocarbons (CFCs). With the exception of methane, the historical emissions estimates presented in this report are only slightly revised from those in last year`s report.
Date: October 1, 1996
Partner: UNT Libraries Government Documents Department

Carbon dioxide, hydrographic, and chemical data obtained in the South Pacific Ocean (WOCE Sections P16A/P17A, P17E/P19S, and P19C, R/V Knorr, October 1992--April 1993)

Description: This data documentation discusses the procedures and methods used to measure total carbon dioxide concentration (TCO{sub 2}) and partial pressure of CO{sub 2} (pCO{sub 2}) in discrete water samples collected during three expeditions of the Research Vessel (R/V) Knorr in the South Pacific Ocean. Conducted as part of the World Ocean Circulation Experiment (WOCE), the first cruise (WOCE Section P16A/P17A) began in Papeete, Tahiti, French Polynesia, on October 6, 1992, and returned to Papeete on November 25, 1992. The second cruise (WOCE Section P17E/P19S) began in Papeete on December 4, 1992, and finished in Punta Arenas, Chile, on January 22, 1993. The third expedition (WOCE Section P19C) started in Punta Arenas, on February 22 and finished in Panama City, Panama, on April 13, 1993. During the three expeditions, 422 hydrographic stations were occupied. Hydrographic and chemical measurements made along WOCE Sections P16A/P17A, P17E/P19S, and P19C included pressure, temperature, salinity, and oxygen [measured by conductivity, temperature, and depth (CTD) sensor], as well as discrete measurements of salinity, oxygen, phosphate, nitrate, nitrite, silicate, chlorofluorocarbons (CFC-11, CFC-12), TCO{sub 2}, and pCO{sub 2} measured at 4 and 20 C. In addition, potential temperatures were calculated from the measured variables.
Date: June 1, 1998
Creator: Rubin, S.; Goddard, J.G.; Chipman, D.W.; Takahashi, Taro; Sutherland, S.C.; Reid, J.L. et al.
Partner: UNT Libraries Government Documents Department

Products of motor burnout. Second quarterly technical report, October 1, 1994--December 31, 1994

Description: The OSP (Operating Safety Procedure) required for performance of electrical arc testing of CFC replacement fluids was renewed. Electrical breakdown tests at one atmosphere pressure have been performed for R-22, R-134a, and R-125/R-143a (50:50 blend; R-507), and breakdown products identified. No differences in HCFC breakdown products are seen in the presence or absence of lubricant oils. The design of the high pressure-high temperature test stand has been finalized, and construction initiated during this quarter. Three motor stators and rotors were received from Tecumseh Products Company for use in motor burnout tests. A test plan for the motor breakdown tests is in preparation.
Date: January 15, 1995
Creator: Hawley-Fedder, R.
Partner: UNT Libraries Government Documents Department

Development of environmentally conscious cleaning process for leadless chip carrier assemblies. Final report

Description: A cross-functional team of process, product, quality, material, and design lab engineers was assembled to develop an environmentally friendly cleaning process for leadless chip carrier assemblies (LCCAs). Using flush and filter testing, Auger surface analysis, GC-Mass spectrophotometry, production yield results, and electrical testing results over an extended testing period, the team developed an aqueous cleaning process for LCCAs. The aqueous process replaced the Freon vapor degreasing/ultrasonic rinse process.
Date: April 1, 1995
Creator: Adams, B.E.
Partner: UNT Libraries Government Documents Department

Carbon dioxide, hydrographic, and chemical data obtained during the Thomas Washington Cruise TUNES-3 in the equatorial Pacific Ocean (WOCE Section P16C)

Description: This data documentation discusses the procedures and methods used to obtain total carbon dioxide (TCO{sub 2}), total alkalinity (TALK), hydrographic, and chemical data during the Research Vessel Thomas Washington Expedition TUNES-3 in the Equatorial Pacific Ocean (Section P16C). Conducted as a part of the World Ocean Circulation Experiment (WOCE), the cruise began in Papeete, Tahiti, on August 31, 1991, and finished in Honolulu, Hawaii, on October 1, 1991. WOCE Meridional Section P16C along 150{degree}W and between 18{degree}S and 19{degree}N was completed during the 31-day expedition. All 105 hydrographic and 8 large-volume stations were completed to the full water column depth. Station spacing was 30 nautical miles (nm), except between 3{degree}N and 3{degree}S where it was 10 nm. Twenty-five bio-optics stations were sampled for the Joint Global Ocean Flux Study, and at 21 stations carbon dioxide measurements were provided for the US Department of Energy`s CO{sub 2} program. Hydrographic and chemical measurements made along WOCE Section P16C included pressure, temperature, salinity, and oxygen measured by conductivity, temperature, and depth sensor; and bottle salinity, oxygen, phosphate, nitrate, nitrite, silicate, chlorofluorocarbon (CFC)-11, CFC-12, TCO{sub 2}, and TALK. In addition, potential temperatures were calculated from the measured variables.
Date: December 1, 1996
Creator: Goyet, C.; Guenther, P.R.; Keeling, C.D.; Talley, L.D. & Kozyr, A.
Partner: UNT Libraries Government Documents Department