The so-called indirect evaporative cooling technology is widely used in air conditioning applications.The thermal characterization of tube-type indirect evaporative coolers,however,still presents challenges which need...The so-called indirect evaporative cooling technology is widely used in air conditioning applications.The thermal characterization of tube-type indirect evaporative coolers,however,still presents challenges which need to be addressed to make this technology more reliable and easy to implement.This experimental study deals with the performances of a tube-type indirect evaporative cooler based on an aluminum tube with a 10 mm diameter.In particular,the required tests were carried out considering a range of dry-bulb temperatures between 16℃ and 18℃ and a temperature difference between the wet-bulb and dry-bulb temperature of 2℃∼4℃.The integrated convective heat transfer coefficient inside the tube in the drenching condition has been found to lie in the range between 36.10 and 437.4(W/(m^(2)⋅K)).展开更多
A simplified model for analysis of heat and mass transfer between air stream and flowing down water film in counter-flow plate heat exchanger which serves as an indirect evaporative cooler is theoretically analyzed in...A simplified model for analysis of heat and mass transfer between air stream and flowing down water film in counter-flow plate heat exchanger which serves as an indirect evaporative cooler is theoretically analyzed in this paper. Indirect evaporative cooler is used for sensible cooling of air which then is used for air conditioning purposes. Mathematical model was developed allowing determining heat transfer surface, outlet air temperature and specific humidity of the air being cooled. To make the model simpler some simplifications have been incorporated. The model has high level of correctness and can be used to calculate and design different types of evaporative heat exchangers. Analysis of results of calculations by the help of the developed model prove that the surface of heat exchanger depends on the thickness of water film layer by the regularity of direct proportionality. Moreover, increasing of the water film thickness brings to the decreasing of the efficiency of evaporative type heat exchanger. The model can be used for correct calculation and design of an evaporative cooling air conditioning systems.展开更多
基金This work was supported by Natural Science Basic Research Program of Shaanxi(2021JQ-689).
文摘The so-called indirect evaporative cooling technology is widely used in air conditioning applications.The thermal characterization of tube-type indirect evaporative coolers,however,still presents challenges which need to be addressed to make this technology more reliable and easy to implement.This experimental study deals with the performances of a tube-type indirect evaporative cooler based on an aluminum tube with a 10 mm diameter.In particular,the required tests were carried out considering a range of dry-bulb temperatures between 16℃ and 18℃ and a temperature difference between the wet-bulb and dry-bulb temperature of 2℃∼4℃.The integrated convective heat transfer coefficient inside the tube in the drenching condition has been found to lie in the range between 36.10 and 437.4(W/(m^(2)⋅K)).
文摘A simplified model for analysis of heat and mass transfer between air stream and flowing down water film in counter-flow plate heat exchanger which serves as an indirect evaporative cooler is theoretically analyzed in this paper. Indirect evaporative cooler is used for sensible cooling of air which then is used for air conditioning purposes. Mathematical model was developed allowing determining heat transfer surface, outlet air temperature and specific humidity of the air being cooled. To make the model simpler some simplifications have been incorporated. The model has high level of correctness and can be used to calculate and design different types of evaporative heat exchangers. Analysis of results of calculations by the help of the developed model prove that the surface of heat exchanger depends on the thickness of water film layer by the regularity of direct proportionality. Moreover, increasing of the water film thickness brings to the decreasing of the efficiency of evaporative type heat exchanger. The model can be used for correct calculation and design of an evaporative cooling air conditioning systems.
