Theoretical And Experimental Study On The Performance Of R290 In Coil-Tube Type Ice Storage Air Conditioner

In the context of global warming and double-carbon goal environment,exploring the application of environmental refrigerant and striving for decarbonization of refrigeration industry has become one of the important research topics.Refrigerant R290(propane)has excellent environmental protection and thermodynamic properties,which will has a good development prospect in the air conditioning industry air-conditioning.Combined of the mature cool-storage technology,This paper proposes to use R290 substituting for R134 a to establish an R290 household cold storage air-conditioning system to improve efficiency and reduce costs while reducing the damage to the environment by traditional refrigerant.Firstly,this paper analyzes and compares R290 and R134 a from three aspects: basic physical properties,thermal performance,and safety.The results show that: Compared with R134 a,R290 is more environmentally friendly.It is difficult to dissolve in water,has stable chemical properties and good thermal conductivity.In addition,it’s compatible with traditional refrigeration equipment and materials,and there is no problem in the safe use of small doses.Then,based on the performance of the cold storage air conditioning cycle,the thermodynamic calculations are performed on R290 and R134 a respectively,and the results show that the R290 system has a higher unit volume refrigeration capacity and unit mass refrigeration capacity,and can obtain a refrigeration COP that is basically equivalent to that of the R134 a system;at the same evaporating temperature,The pressure ratio and exhaust temperature of the R290 system are lower than those of the R134 a system,and the exhaust pressure is also within the normal pressure range.Based on theoretical analysis,the coil-tube type ice storage experiment system is built for experimental verification.This paper has completed the processing and construction of cold storage tank,condenser,compressor,electric control cabinet and other equipment,in the end,debugs the refrigeration system.The experimental research on the performance of the R290 in coil-tube type ice storage system is divided into two parts.The refrigerant filling test shows that: too little or too much refrigerant charge will have a negative impact on the cold storage performance of the system.The optimal charge range of R134 a is 1300～1400g,and the optimal charge range of R290 is 500～600g.The optimal charging rate is only 43%～46%of R134 a,which is beneficial to reduce the risk of explosion of R290 cold storage air conditioner.The experiment also compares the performance of the two under the optimal charging rate in cool-storage conditions,and the results show that: R290 has a fast cooling rate,which can shorten the cold storage time,and the unit average cooling capacity of the system is about 52% higher than that of R134 a.In addition,the lower exhaust temperature and pressure ratio of the R290 system are helpful to the stable operation of the system.Through theoretical analysis and experimental testing,this paper summarizes the feasibility of replacing R134 a with R290,and verifies the advantages of R290 in the cold storage condition with rapid temperature drop and high efficiency.