Conditions for Compliance Lewis Relationship When Air Flow is Contact with Ice

Abstract

AbstractThe purpose of the article is to check the observance of the theoretical value of the ratio of the heat transfer and moisture transfer coefficients in schemes with direct contact of air flow and ice. Such heat and mass transfer is observed in the seasonal accumulation of natural sources of cold for air-conditioning. Therefore, it is necessary to know heat and mass transfer criteria for the engineering design of cold storages. A theoretical analysis of the observance of the constancy of the heat transfer and mass transfer coefficients for different options of the flow of the cooling process of the air flow in schemes with direct contact of air flow and ice has been carried out. Depending on the option of the process and the method of analysis, possible conditions for observing the similarity of heat exchange and mass exchange processes have been identified, however, in most cases, the processes are not similar. The results of theoretical analysis have been compared with the results of modeling heat exchange and mass exchange processes in the experimental installation. The data obtained during the physical experiment shows that the ratio of heat transfer and moisture transport coefficients is not equal to the theoretical value obtained by Lewis for liquid evaporation. The similarity of heat and moisture transfer processes is not observed over the entire experimental range of changes in the partial pressure of water vapor. This shows the necessarity to improve the theory of heat and mass exchange of air flow with natural sources of cold used for accommodation air conditioning systems.KeywordsCold accumulationHeat exchange (transfer)Moisture exchangeConditioningThermodynamic parameters