最新刊期
卷 28 ， 期 4 ， 2007
- 摘要：Room temperature magnetic refrigeration is a new highly efficient and environmentally protective technology, and it shows a great applicable prosperity. In this paper, the new development of the magnetic material is described. The thermal dynamic characters of magnetic refrigeration cycles are analyzed. The porous media model of active regenerator of room temperature refrigeration is discussed based on non - Darcian effects. Some new-style prototypes of room temperature refrigeration are presented. The further research of room temperature magnetic refrigeration is suggested.关键词：pyrology;room temperature magnetic refrigeration;Magnetic material;refrigeration cycle;Active regener-ator;Thermal dynamic analysis;porous media1745|353|0更新时间：2025-09-03
- 摘要：In this paper, the characteristics of ammonia refrigerant are described. The application status and existing problems of ammonia refrigeration systems both in China and abroad are analyzed. The development trends of ammonia refrigeration technology including system optimization, improvement of control technology, safety guarantee, and miniaturization of ammonia systems are discussed. Moreover, some main problems to be solved according to safety requirements of Design Codes and Manuals of ammonia refrigeration systems are indicated. In addition, the ideas of simplifying ammonia systems are presented. It is suggested that the development of smallscale ammonia refrigerant compressors should be speeded up, and the theoretical and experimental studies both on ammonia refrigeration equipment and on practical applications should be emphasized in China.关键词：pyrology;Ammonia refrigeration systems;Safety;Application status;Development Trends1723|372|0更新时间：2025-09-03
- 关键词：pyrology;Cryofreezer;Mixed-refrigerants;Throttle refrigerator;Cryo-preservation1753|361|0更新时间：2025-09-03
- 摘要：Experiments on a reciprocating compressor C- L150M82 using R404A and R22 were conducted under low temperature working conditions. The feasibility of replacing R22 with R404A was analyzed based on the experimental data. The results show that with the same configuration and under the low temperature working condition, the refrigerating capacity of the compressor with R404A is greatly higher than that with R22, if the condensing temperature does not change. With the falling of evaporating temperature, the capacity can rise by 10% - 30%. Moreover, at the same condensing temperature, the evaporating temperature for the compressor using R404A can reach - 45%. Furthermore, the discharge temperature of the compressor using R404A is lower than that using R22 significantly. In addition, the application of both superheat and subcool recycles can improve the performance of R404A refrigeration system.1658|351|0更新时间：2025-09-03
- 摘要：Four different concentration TiO2-BaCl2-H2O nanofluids with 20nm TiO2 were prepared by supersonic oscillator through adding hydrophilic dispersant into BaCl2 solution. BaCl2-H2O and TiO2-BaCl2-H2O nanofluids were tested experimentally. The results show that nanofluids have remarkably lower supercooling degree than BaCl2-H2O, and the beginning nucleation time of nanofluids is ahead of BaCl2-H2O. Moreover, their crystallization time is lower than that of BaCl2-H2O. Also, the crystallization mechanism was analyzed for the influence of the nano TiQ2 particles on BaCl2-H2O.1718|364|0更新时间：2025-09-03
- 摘要：Based on the experimental results, thermodynamic properties models and transport properties models of HFC236ea were established. The state equation of HFC236ea was regressed on the basis of Soave-Redlich - Kwong model. The evaporation latent heat model of HFC236ea was achieved by Clausius-Clapegron equation. Coefficient of viscosity, coefficient of heat transfer and other transport properties equations of HFC236ea were built by various polynomial models. In addition, the lgp - h diagram of HFC236ea was drawn out according to the thermodynamic properties models. The error analysis shows that the present models can meet the calculation precision requirement.1665|363|0更新时间：2025-09-03
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- 摘要：A combined cold and heat system driven by a gas engine was set up, The performance of cooling and heating was tested under the nominal conditions of air conditioning. The results show that the cooling heating capacity was 476. 1 kW and 148.7 kW, respectively. Primary energy rate was about 1.9 and energy saving ratio is 37.8%, compared with the conventional cooling and heating system. The effect of the gas engine speed on cooling and heating capacity was also tested. Cooling and heating capacity of the combined system decreased with the decrease of the gas engine speed, but primary energy rate increased with the decrease of the gas engine speed. It may be suggested that the speed of the gas engine be prior to all control parameters under part - load conditions to ensure higher primary energy rate of the system.关键词：Power machinery and engineering;Gas engine;Combined cold and heat;vapor compression refrigeration;Recovery of waste heat1594|367|0更新时间：2025-09-03
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- 摘要：The evaporation heat transfer was experimentally investigated for the slim, cross, smooth and general micro - fin tubes in our study. The results show that the heat transfer coefficients increase with the refrigerant mass flow rate for all tested tubes. The heat transfer coefficient of the cross micro-fin tube is 10% higher than that of the slim micro - fin tube, and again the latter is 10% higher than that of the general micro - fin tube. The pressure drop of the cross micro- fin tube is higher than that of the other micro - fin tubes. Based on the steady state distributed parameter model and the same configuration and test conditions, the performance of evaporators using the these four micro-fin tubes were calculated and compared with each other. The results indicate that the performance of the cross micro - fin tube evaporator is superior to the other evaporators. The pressure drop for the four evaporators is almost identical with a slightly higher pressure drop for the smooth tube evaporator.关键词：engineering thermophysics;Micro-fin tube;Evaporation;experimental research;numerical simulation1501|360|0更新时间：2025-09-03
- 摘要：Experimental studies were conducted at different pressures and temperatures for hypobaric and refrigerated storage of goldpears. Several factors such as storage effects, water losing rate at different storage conditions were analyzed. In addition, the suitable storage parameters for the gold - pears during hypobaric and refrigerated storage conditions were obtained.关键词：horticulture;Vegetable cold chain;Hypobaric and refrigerated storage;Gold-pear1596|349|0更新时间：2025-09-03
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