共查询到19条相似文献,搜索用时 93 毫秒
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本文引入一种基于基团贡献的逸度系数模型来解决常规模型对非共沸混合制冷剂气液相平衡预测精度不足的问题,该模型只使用较少的共性基团参数就能推算大量多元混合物的物性.使用PR状态方程结合vdW混合规则来描述气相逸度、UNI-FAC模型来描述液相逸度.通过对R32+R236fa非共沸混合工质对的气液相平衡饱和蒸汽压力进行计算,并将结果与实验数据、REFPROP 8.0商业软件计算值对比分析.结果 表明:本文模型比REFPROPS.0软件更适应于混合工质;此外,该模型只考虑基团间相互作用,简化了热物性计算.基于提出的模型,绘制了R32+R236fa非共沸混合工质在278.15~363.15 K的相图. 相似文献
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HFC/HC混合工质的气液性平衡实验研究结果表明,该类型混合工质大多存在共沸现象。根据形成共沸点的热力学条件,以PR状态方程结合vdW混合法则,利用建立的二元相互作用系数kij差值关联模型,对10种HFCs工质(HFC23、HFC32、HFC125、HFC143a、HFC134a、HFC152a、HFC227ea、HFC236fa、HFC236ea、HFC245fa)与3种HCs工质(HC290、HC600a、HC600)相互组合而成的30种HFC/HC混合工质进行了共沸点判断和共沸点性质推算,并与已有气液相平衡实验数据的体系进行对比。结果表明该方法可用于推算HFC/HC混合工质共沸点性质。 相似文献
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《Heat Recovery Systems and CHP》1991,11(6):505-515
The dynamic behaviour characteristics of some non-azeotropic refrigerant binary mixtures have been experimentally studied at various concentrations. The study was performed on a water/air heat pump during the heating mode under start-up conditions. The results presented in this study showed that the state of the non-azeotropic refrigerant mixture and its composition and concentration have a significant effect on the heat pump performance during start-up.In addition, the study demonstrated that non-azeotropic refrigerant mixtures could be potential CFC substitutes in heat pump applications. 相似文献
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《Heat Recovery Systems and CHP》1992,12(4):289-302
In this paper, an experimental investigation of the steady state and dynamic behaviour of a new efficient exhaust heat pump is presented. The proposed system uses environmentally sound non-azeotropic refrigerant mixtures as working fluids.Results showed that the performance has been significantly enhanced by the use of non-azeotropic refrigerant mixtures over R-22. 相似文献
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《Heat Recovery Systems and CHP》1991,11(5):393-405
In this study, a numerical model has been developed to predict the behaviour of non-azeotropic refrigerant mixtures in smooth as well as textured gravity assisted heat pipes.In addition, experiments were performed on fully instrumented heat pipes using pure as well as non-azeotropic refrigerant mixtures to determine their heat-transfer characteristics. The effects of operating conditions on the transport capability have been measured and analyzed.Numerical results showed that the proposed model favourably predicted the performance of the heat pipes under various conditions and compared well with experimental data. 相似文献
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