非共沸工质非完全冷凝实验现象及判据的验证

Experiment and Criterion of Incomplete Condensation of Zeotropic Mixtures

针对非共沸工质可能出现的非完全冷凝现象,首先针对两种非共沸工质进行了实验研究,得到制热量和COP随冷凝器水流量逐渐增加的变化规律,证明非完全冷凝现象存在的可能性和普遍性;然后根据已经提出的此现象是否发生的理论判据(极限流量判别式)进行计算,并用实验测得极限流量对其进行验证;最后,分析了实验与理论计算的差异和原因,并提出完善非完全冷凝现象理论判据的改进方向,即考虑工质在冷凝器中的压降、工质和换热流体间的实际温差和实际换热过程中的各种外力。

Incomplete condensation may occur for zeotropicmixtures used. Experiments for two zeotropic mixtures were conducted and the variation of heating capacity and COP with the increase of water flow rate in a condenser was obtained to confirm the possibility of incomplete condensation. Moreover, an incomplete condensation criterion, a maximum flow rate discriminant, was used for calculation and was verified by the maximum flow rates measured. The difference between experimental and theoretical results was analyzed. It is suggested that pressure drop of zeotropic mixture in a condenser, temperature difference between zeotropic mixture and heat transfer fluid, and other forces during heat exchange should be considered in the criterion.