Heating Performance of Zeotropic Mixture and Temperature Glide Matching with Secondary Fluid
In order to decrease the heat rejection pressure of pure CO2 refrigerating system and meanwhile have sustainable environmentally benefits for working fluild, several natural zeotropic CO2/Propane mixtures are applied to heat pump system to investigate the heating performance. The heat rejection pressure of CO2/Propane mixtures is reduced when the mass fraction of carbon dioxide is decreased. Under the given conditions, there is an optimum range of mass fraction of CO2/Propane of which the mixtures have superior heating coefficient of performance. The temperature glide characteristics of CO2/Propane mixtures at heating mode was also researched to analyze the heat transfer efficiency. Both a sufficient heat exchange area and a good working fluid’s temperature gradient matching with that of the secondary heat transfer fluid contribute to a higher heat transfer efficiency of heat exchanger.
X. P. Zhang et al., "Heating Performance of Zeotropic Mixture and Temperature Glide Matching with Secondary Fluid", Key Engineering Materials, Vols. 474-476, pp. 1657-1660, 2011