Study On Air-conditioning System With Double Heat Recovery Equipment Using Heat Pipe

Heat pipe with several qualities of super thermal conductivity,stability,small volume and controllability is widely utilized in central air conditioning system.The optimization of heat pipe performance and the development of new heat pipe have also become a hot research topic.In the pursuit of the secondary heat recovery with heat pipe exchanger,a secondary heat recovery heat pipe air conditioning(AC)system was proposed in this paper.We designed and performed this system and set up laboratory bench.What' more,we compared the differences between the system and other systems with theory calculation in this paper.(1)By means of the difference among the system,no heat pipe heat recovery system and normal heat pipe heat recovery system,all-season energy consumption of air condition system was decreased in this system which is combined of porous wick heat pipe exchanger and capillary pump loop heat exchanger.This article used Hefei as a sample,analyzed the energy-consumption of the system in winter and summer.In contrast to no heat pipe air condition system,the 25.7%energy-consumption could be economized in winter,the 22.1%energy-consumption could be economized in summer.Compared with the normal heat pipe heat recovery system energy-consumption,the 25%energy-consumption could be economized in winter,the 22.1%energy-consumption could be economized in summer.(2)According to the requirements of the system,the heat pipe is designed and calculated,the physical and thermal parameters of the heat pipe and heat pipe heat exchanger are designed,and the performance is checked.(3)According to the analysis of experimental data,when the winter fresh air wind velocity is 1.20?1.85 m/s,the heat recovery rate reaches 10%?23.2%.As the summer fresh air velocity is 1.20?2.0m/s and the air temperature difference between indoor and outdoor is 4.2?8.0?,the heat recovery can reach 35%?55%.Meanwhile,the reheat temperature difference is 0?7.4? was provided for air supply.The results indicate that secondary heat recovery HPHE AC system has a unique energy-saving advantage.(4)The asymmetric theory of heat transfer is proposed and the principle formula is deduced to explain the cyclical fluctuation of the temperature difference between the two ends of the heat exchanger,the time effect is lagging,the heat gain is not equal and the thermal efficiency is periodically fluctuating.