【作者】 刘焕卫；

【导师】 杨昭；

【作者基本信息】 天津大学 ， 制冷及低温工程， 2012， 博士

【摘要】 节能和环保等问题日益受到国际社会的广泛关注,也成为制冷热泵行业的研究热点。独立式燃气机热泵系统是以天然气或其他清洁能源为一次能源输入,为建筑物提供冷、热、生活热水及系统自备电的节能环保新系统。本文主要针对独立式燃气机热泵系统及新型环保制冷剂进行了理论和实验研究。在新型环保制冷剂方面,采用热工性能优异、市场可获得性、低GWP以及ODP为零的环保制冷剂,并对具有可燃性的环保制冷剂进行了惰化及爆炸极限实验研究。本文对阻燃制冷剂与可燃组元DME、R32、R152a、R290形成的二元混合物在常温常压下进行了爆炸极限实验研究,得到了混合物的爆炸上、下限以及阻燃剂的最小惰化浓度。在此基础上,应用基团贡献法和燃烧学相关理论对上述阻燃制冷剂的抑制系数进行了计算分析,并提出了计算阻燃制冷剂最小惰化浓度的理论估算公式。通过理论估算值和实验测量值之间对比分析可知:在可燃制冷剂火焰传播速度测量(计算)准确前提下,理论估算值和实验结果基本吻合。理论估算公式对可燃制冷剂的理论分析、实验研究以及实际应用等具有重要的指导意义。建立了工质循环性能实验系统,对通过理论分析获得的一种HCFC-22替代制冷剂和一种中高温制冷剂在此实验台上进行了循环性能实验研究。实验结果表明:替代制冷剂充灌HCFC-22系统中,其在相同工况下的制冷量、压比、排气温度以及制冷性能系数均比HCFC-22优异,两者压缩机功率接近,是一种较为理想的HCFC-22替代物;中高温制冷剂充灌HFC-134a系统中,可获得高于80℃的热水,其排气温度为95.3℃、排气压力为1.93MPa、压比小于6.0。在蒸发器进水温度44℃、冷凝器出水温度80℃时,系统性能系数达到2.92。在独立式燃气机热泵供能系统方面。基于替代HFC-134a的新型环保制冷剂,进行了制冷、制热性能实验研究,并对影响独立式燃气机热泵系统的因素(制冷工况——蒸发器进水流量、蒸发器进水温度以及燃气发动机转速等;制热工况——冷凝器进水流量、冷凝器进水温度、燃气发动机转速以及蒸发温度等)进行了定量和定性分析,为独立式燃气机热泵系统的示范及进一步的推广应用奠定了基础。制冷和制热工况性能实验结果表明:独立式燃气机热泵系统应用新型环保制冷剂可获得较高的性能系数(COP)和一次能源利用率(PER)。更多还原

【Abstract】 As the international community pays more and more attention to the energy conservation and environmental protection, which is also becoming a research focus in the refrigeration and heat pump industry. The independent gas engine driven heat pump system (IGEHP) used natural gas or other clean energy as an independent energy input could provide the heating, cooling, hot water and autonomous power supply system. This article has mainly carried out the theoretical and experimental research on the independent gas engine driven heat pump system and new environment-friendly refrigerants.In the aspect of refrigerant, a series of new environment-friendly refrigerants with advantages of thermo-physical properties, market availability, lower global warming potential (GWP) and zero ozone depletion potential (ODP) were adopt. At the same time, the explosion limits of binary mixtures which include nonflammable refrigerants and flammable refrigerants DME, R32, R152a and R290s has been experimentally studied under the conditions of 290~295K and 101.325KPa (one atmosphere pressure, 760mm Hg). Furthermore, parameters of upper flammability limit (UFL), lower flammability limit (LFL) and minimum inert concentration (MIC) of nonflammable refrigerants were also obtained. On this basis, the inhibition coefficient of nonflammable refrigerants was analyzed and a novel equation of predicting the minimum inert concentration of nonflammable refrigerant has been proposed by analyzing the group contribution method and the theory of combustion in binary mixtures. Comparative analysis of the theoretical calculated values and experimental data, the result demonstrates that the theoretical data are in good agreement with experimental results under the condition of flammable refrigerants flame propagate velocity and the stoichiometric concentration exactly, and the novel equation is an excellent tool to analyze the minimum inerting concentration of nonflammable refrigerant. The theoretical results have significance on flammability experimental, theoretical research and the security application.The refrigerants cycle performance test-bed was built up, and performances of two mixture refrigerants (alternative for HCFC-22 and moderately-high temperature refrigerant) have been carried out in this water-to-water cycle performance heat pump system. The results show that the alternative mixture refrigerant can directly charge into the HCFC-22 heat pump system, and the performance of cooling capacity, pressure ratio, discharge temperature and coefficient of performance (COP) are better than that of HCFC-22, on the other hand, the compressor power between the alternative mixture refrigerant and HCFC-22 are close to each other. Therefore, this proposed environment- friendly refrigerant is an excellent alternative refrigerant for HCFC-22; The moderately-high temperature refrigerant charged into HFC-134a heat pump system could obtain above 80℃hot water, and the discharge temperature, condenser pressure and the pressure ratio was just 95.3℃, 19.3MPa and 6.0, respectively. The COP of this mixture refrigerant M2 was above 2.92 under the condition of evaporator water inlet temperature 44℃and condenser water outlet temperature 80℃.In the independent gas engine driven heat pump system scheme, the cooling and heating performance of independent gas engine driven heat pump using new environment-friendly mixture refrigerant (alternative for HFC-134a) has been experimentally studied. Furthermore, several effected factors (cooling model: evaporator water inlet flow rate, evaporator water inlet temperature and gas engine speeds; heating model: condenser water inlet flow rate, condenser water inlet temperature, gas engine speeds and evaporator temperature) on the independent gas engine driven heat pump system have been qualitatively and quantitatively analysed. The experimental results have laid out a foundation of demonstration and further popularization and application of IGEHP. Finally, the independent gas engine driven heat pump system could obtain better coefficient of performance (COP) and primary energy ratio (PER) using new environment-friendly mixture refrigerant.更多还原