Study Of The Nanorefrigerant Applied In The Automotive Air Conditioning System

The high-efficiency air conditioner would dramatically decrease the energy consumption of the whole automobile,especially the electric vehicle.Therefore,nano-refrigerant gradually captured the worldwide attention due to its excellent heat transfer performance,the application of nano-refrigerant to refrigerant system,according to the pertinent statistics,is an effective method to improve the efficiency of that.This project is mainly on the application of nano-refrigerant in automobile air conditioning system,the flow and heat transfer of nano-refrigerant R134a-Fe₃O₄ were studied via using the technical route of physical property parameter calculation simulation experiment.Through studying the thermophysical properties of nano-refrigerant under different models,a suitable theoretical model was used to solve the equation for calculating the thermophysical properties of nano-refrigerant R134a-Fe₃O₄ at concentrations of 1%,2%,3%,and 5%.Based on the Lattice-Boltzmann method,the heat transfer effect of the nano-refrigerant with different concentrations was obtained by the study on the flow and heat transfer of the nano-refrigerant in the tube from the mesoscopic angle;the CFD simulation method was adopted to study the heat transfer of nano-refrigerant in automobile air-conditioner condensers from the macro perspective,and analyze the flow and heat transfer characteristics of the nano-refrigerant at different concentrations.An automobile air conditioning experimental system was set up to test the refrigerant R134a and the 1%nano-refrigerant R134a-Fe₃O₄,and then the experiment and simulation results will be compared and analyzed.According to the research,nano-refrigerant has a significant increase over the heat transfer performance compared to pure refrigerant.Based on the lattice Boltzmann method,the heat transfer capacity of nano-refrigerant gas R134a-Fe₃O₄ is 39.89%higher than that of R134a refrigerant,and nano-refrigerant liquid is 5.83%higher when the nano-material is in its most efficient state.The CFD simulation results show that the heat transfer capacity of nano-refrigerant gas R134a-Fe₃O₄ is 149.7%higher than that of R134a refrigerant,and the ratio of nano-refrigerant liquid 6.22%.At lab temperature,the COP of the 1%concentration nano-refrigerant R134a-Fe₃O₄ in automobile air conditioning system has increased by 4.75%.From the simulation results and experimental results,it is both found that nano-refrigerant used in automobile air-conditioning system are greatly improved,compared to pure refrigerant,over heat transfer performance and COP.