Application Research Of Condensing Exhaust Air Heat Recovery Fresh Air All-in-one Unit In Laboratory Animal Facilities

In order to deal with the pollution gases and dust particles produced by laboratory animals in daily operation,the laboratory animal facilities adopt all fresh air airconditioning system.Moreover,due to the strict requirements of laboratory animals on environmental parameters,the air conditioning system needs to operate continuously for24 hours,so that the energy consumption of the air conditioning system of laboratory animal facilities is much higher than that of ordinary buildings.Through calculation and analysis,it is found that the fresh air load accounts for the largest proportion of the air conditioning load,so reducing the fresh air load becomes an important way to reduce the energy consumption of air conditioning.This paper proposes to apply the condensing exhaust heat recovery fresh air all-in-one unit in the air conditioning system of laboratory animal facilities to recover exhaust energy,and discusses the energy-saving,applicability and carbon reduction effect of the condensing exhaust heat recovery fresh air all-in-one unit in five different climate zones of laboratory animal facilities.The main work of this paper includes:(1)In the enthalpy difference laboratory,the variable environmental conditions performance test of condensing exhaust air heat recovery fresh air all-in-one unit under cooling and heating conditions was carried out,and the performance curve fitting was carried out with Matlab software.(2)Seven cities are selected as representatives of the five climate zones,and the air conditioning loads of the representative cities are calculated and analyzed.At the same time,the annual operation of the condensing exhaust air heat recovery fresh air all-in-one unit in seven representative cities is calculated and analyzed.(3)Using Designbuilder simulation software as a tool,the physical model of laboratory animal facilities was established and boundary conditions were set.The simulated energy consumption was compared with the actual energy consumption collected,and errors were analyzed to verify the accuracy of the model.The verified model was used to simulate the annual energy consumption of air conditioning system before and after the use of heat recovery devices in seven representative urban laboratory animal facilities,and the heat recovery effect,energy saving and carbon reduction effect were compared and analyzed.The results show that the annual air conditioning load of laboratory animal facilities in the seven representative cities are dominated by fresh air load,and the proportion of fresh air load is higher in the heating mode than in the cooling mode,reaching over 98%.The proportion of fresh air load in the seven representative cities showed a decreasing trend from north to south in heating condition,and vice versa in cooling condition.Therefore,it is of great potential to take energy-saving measures to reduce the energy consumption of air conditioning system from the fresh air load.The stage of heat recovery units which meet cooling and heating demand in Urumqi,Shenyang,Beijing,Xi’an,Suzhou,Guangzhou and Kunming is 6047 h,6797 h,7898 h,8523 h,8760 h,8704 h,and8760 h,respectively.Through simulation and comparative analysis using Designbuilder,it was found that Urumqi(severe cold zone)and Shenyang(severe cold zone)showed the most significant energy-saving effect after adopting the heat recovery device,with a comprehensive energy saving rate of 20.56% and 21.23% respectively throughout the year.Beijing(cold zone)and Xi’an(cold zone)ranked second,with comprehensive energy saving rates of 16.58% and 14.05% respectively throughout the year.Heat recovery is applicable throughout the year in Suzhou(hot summer and cold winter zone),and the annual comprehensive energy saving rate is 11.82%.In Guangzhou(hot summer and warm winter zone),the main energy saving condition is cooling condition,and the heat recovery effect is relatively poor under heating condition.The annual comprehensive energy saving rate reaches 8.25%.Kunming(temperate zone)is not recommended to promote the heat recovery device,the annual comprehensive energy saving rate is low,only 3.20%.The carbon reduction and carbon reduction rate after adopting the heat recovery technology in Urumqi,Shenyang,Beijing,Xi’an,Suzhou,Guangzhou,and Kunming are 128.65 t,20.56%;104.91 t,21.23%;77.20 t,16.58%;65 t,14.05%;51.15 t,11.82%;29.18 t,8.25%,and 8.08 t,3.25%,respectively.