Experimental Research And Analysis Of Low Temperature Heat Pump Air Conditioning System For Electric Vehicles

The development of electric vehicles is the inevitable result and objective needs of the automotive technology advances, new energy technology development, socio-economic development. With the technical characteristics of energy saving, it can well solve the problem of controlling vehicle emissions and save a lot of oil resources. As a very promising vehicles, to provide a comfortable indoor environment for passengers is also essential for electric vehicles.In cold regions, the current electric cars with common heat pump air conditioning system in the condition of low temperature circulating heating operation with the problems of compression ratio is too large, the exhaust temperature is too high, which can’t meet the requirements of vehicle interior heat and comfort problems claims.This research is the application of the jet with the economy the quasi two-stage compression heat pump low temperature automotive air conditioning, to solve the above problem has a great role in promoting the beneficial results of its electric cars to expand low heat pump air conditioning use (-15℃) range, promote the improvement of automobile air conditioner in heating operation efficiency of energy use.This topic first mainly for discussing the low-temperature heat pump electric vehicle air conditioning systems, introduces the two-stage compression heat pump in the middle of the car injection cycle and the scroll compressor which used in the low-temperature heat pump system.And on the jet with the economic principle of quasi-two-stage compression cycle system uses a theoretical analysis, based on the theoretical analysis of the electric car prototype low-temperature heat pump air conditioning system in determining the vehicle interior temperature, the outdoor ambient temperature change car carried out under heating performance experimental study of the gantry, analyze the impact of changes in the car on the outdoor temperature low temperature heat pump electric vehicle air conditioning system thermal performance data from the experimental results, in addition to the experimental results can be seen from the low-temperature heat pump air conditioning system electric vehicles can effectively avoid the ordinary high compressor discharge temperature heat pump system and inadequate heating performance problems exist in low temperature conditions. Then this research process, low temperature heat pump air conditioning system will be installed on a particular brand of small electric car, the high-temperature air conditioning and refrigeration ring mold test, low temperature heating test vehicle, verify its air conditioning in the real vehicle environment the effect of temperature inside the car can be adjusted to allow the crew to get comfortable level.Finally, based on the second law of thermodynamics for various components of electric vehicles cryogenic heat pump air conditioning systems and heating systems running exergy analysis to arrive at a low temperature heat pump air conditioning system at the time in order to operate the heat pump, the effective energy loss areas, thus symptomatic and rule, the result is to improve the work done to improve the efficiency of the compressor with the pseudo-second spray of economic energy efficiency of key electric vehicle low compression heat pump system. The second is the improvement of vehicle external heat exchanger and the interior heat exchanger is also to improve the low temperature heat pump system for energy efficiency levels.