Numerical Simulation And Application Research Of R404A Air-source Heat Pump For Heating In The Ski Venue

Air source heat pump is widely used in south of Yangtze for its safety,environmental protection,high efficiency and energy saving features.Throughout the 2016 market,air source heat pump industry total capacity exceeded RMB 80 billion which is a big improvement for the development of air source heat pump industry.Due to low ambient temperature,air source heat pump units will appear compressor start-up difficulties,high exhaust temperature,low heating capacity which restrict the air source heat pump in the north cold area of popularization and application in winter.CFCs and HCFCs?such as R12 and R22?which are widely used in refrigeration industry.Such working mediums have serious damage effect to the ozone layer.Internationally,the use of natural industrial materials such as CO₂ and HFCs are being gradually used,such as R404 A.HFCs have none damage to the ozone layer.The exhaust temperature is lower than other working medium when R404 A is used in air source heat pump,so using R404 A air source heat pump system is proposed in this paper.This article compares R404 A with R22,R410 A,R407C in properties.Calculate the performance in ordinary single stage compression air source heat pump cycle of these working mediums,results show that the low temperature adaptability of the R404 A system is the most stable,compressor exhaust temperature is the lowest.R404 A fill gas enthalpy of low temperature air source heat pump system and the cycle parameters are calculated,compared with single stage compression system,results show that R404 A fill gas enthalpy of low temperature air source heat pump system has a better adaptability and stability at low temperature.The 2022 Beijing winter Olympics is held in ChongLi.Now ski venue heating system heat source is R404 A single stage compression air source heat pump system and CO₂ air source heat pump system?scheme 1?with a variety of cooling end?fan coil + geothermal coil,hot air curtain?to ensure venues heating demand.Because R404 A single stage compression air source heat pump system works badly in low temperature,so this paper proposes R404 A EVI air source heat pump system to replace the R404 A single stage compression air source heat pump system,cooperating with CO₂ air source heat pump system for heating the venue?scheme 2?.GAMBIT is applied to establish physical model and meshing.Then using FLUENT software to do numerical simulation research under different schemes of indoor thermal environment.It turns out that using EVI heat pump and CO₂ heat pump system can assure indoor heating temperature above 16 ? on the basis of removing the fan coil.Compared the actual investment and its operation with the two schemes in some aspects,such as: economic,environmental benefits and energy efficiency.Compared with the electric boiler heating system,also it is concluded that the economic benefits of using air source heat pump heating system is better,the conclusion of environmental protection and energy savingbenefits is more apparent.Through the above work,it is concluded that R404 A EVI air source heat pump system can be used to heat source with floor heating system cooling end,and the original CO₂ air source heat pump as a heat source with hot air curtain cooling end,can guarantee the heating demand of venues,more economical,more energy efficient than current heating system.It is in line with the low carbon environmental protection concept of less investment.It is very important to further enlarge the application of air source heat pump as the heat source of winter heating in the north.