As we all know, automobile air conditioning system isone of the most important devices to regulate the temperature and air insidethe automobile. The technical level of automobile air conditioning system willdirectly affect the temperature inside the automobile and the effect of airconditioning. In terms of technology development trend, with the change ofautomotive energy driving the development of new energy vehicles, thedevelopment of automotive air conditioning technology also focuses on the followingaspects: compressor electric drive, heat pump cycle auxiliary PTC forheating, high efficiency and lightweight heat exchanger, battery thermalmanagement, comfort and so on. [1] Modern automobiles are generally equippedwith air conditioning systems, which are used to improve the comfort of driversand passengers. The comfort brought by automobile air conditioning is mainlyreflected in the temperature and humidity of the air in the car, the airfreshness and other parameters. The automobile can adjust the interiorenvironment to the most suitable state for human body. [2]

In this context, if the effective application level offuel cell vehicle air conditioning system is improved, it will become one ofthe key research projects. In fact, there are obvious differences betweentraditional fuel vehicle ground air conditioning system and new energy vehicleair conditioning system. Relevant personnel should strengthen the structuraldesign of air conditioning system, so as to ensure the comfort of new energy vehicleair conditioning. On this basis, we will promote the healthy development of newenergy automobile industry in China.

The traditional air conditioning (AC) system consistsof a compressor driven by an engine driven by an electric clutch. Air conditioningadds extra load to the engine of a car by increasing fuel consumption, whichleads to greater emissions. [3] The technology of new energy automobile airconditioning system in our country is developed from the traditional fuelautomobile air conditioning system, which means that the operation structure ofnew energy automobile air conditioning system in our country is similar to thatof traditional fuel automobile air conditioning system to a certain extent. Theworking principle of new energy automobile air conditioning system is the sameas that of traditional fuel system air conditioning system. The electriccompressor of new energy automobile air conditioning system is driven by highvoltage electricity. The electric air conditioning compressor compresses thelow pressure and low temperature steam from evaporator, pressurizes it tocondenser, and makes refrigerant circulate around the system. [4] According tothe actual situation of new energy vehicles, the air-conditioning system of newenergy vehicles is mainly divided into waste heat utilization refrigerationair-conditioning system and heat pump air-conditioning system directlyutilizing electric energy. Heat pump system is a reasonable and feasiblechoice, if it can solve some key problems. Mobile climate control system basedon Magnetocaloric Effect and thermoelectric effect is a complementary methodfor future application. [5] Because the automobile air conditioner firstadjusts the air temperature inside the carriage, it reduces the air temperatureby refrigeration. At present, thermoelectric refrigeration, electric compressorrefrigeration and waste heat refrigeration are the main refrigerationregulation modes for electric vehicle system in China. [6] The use of theseair-conditioning systems will have a certain impact on the structure andfunction of new energy vehicles, so it is necessary to strengthen the analysisand understanding of automobile air-conditioning system technology.Refrigeration system and heating system are two major energy-consuming parts ofair-conditioning system. The main energy consumption of refrigeration system isconcentrated on compressor. It generally needs to consume high-grade energysuch as mechanical energy or electric energy. The energy consumption of heatingsystem is larger, but it can use low-grade energy such as waste heat. [7]

The air conditioning system of new energy vehicles notonly needs to meet the refrigeration needs of new energy vehicles, but alsoneeds to meet the heating needs of new energy vehicles. Because the mainoperating power of new energy automobile air conditioning system comes frommotor and its energy source comes from power battery, the heating mode of airconditioning system can meet the needs of both PTC heating and electric heatingpipe heating modes at the same time, and often adopts the mode of direct use ofbattery power to drive the operation of electric compressor. Other data showthat the system can use the potential energy of compressed hydrogen as the maindriving energy to produce cooling effect for air conditioning and so on. [8]

According to the air-conditioning function of fuelcell vehicle, it can be divided into single-cooling air-conditioning, heat pumpair-conditioning and electrically assisted heating air-conditioning. [9] Forrefrigeration systems, new technologies are used to improve COP values, such ashigh efficiency low temperature differential heat exchanger technology(including evaporator and condenser), energy recovery throttle expansion deviceand high efficiency compressor technology. For heating system, we hope torecover waste heat as much as possible. When the waste heat is small enough tomeet the demand, we should try to reduce the consumption of high-grade energy.If the heat pump heating technology can be studied, the technology cantheoretically achieve more than 3 heating energy efficiency ratio. Electricvehicle heat pump air conditioning system is the development trend. In the airduct of heat pump air conditioning system, the structure of in-car condenserand evaporator is adopted. The refrigerant absorbs the heat load and transfersit to the environment through the condenser. The refrigerant is moved by thecompressor. The power required to supply the compressor comes from the powersource of the vehicle: fuel cells and/or batteries, depending on the controlstrategy. [10]

At present, most domestic automotive enterprises useelectric compressors to drive their work directly by using battery powersupply. Although electric compressors are more important than brushlesspermanent magnet DC motors, if we want to promote some key technologies of newenergy vehicles nationwide, we need to understand urgently. Because the mostadvanced air conditioning systems are not completely sealed and traditional refrigerantsare harmful to the climate (GWP-1400), their emissions must be taken intoaccount on the road to zero-emission vehicles. [11]

It can be predicted that the future developmentdirection of new energy automotive air conditioning system technology in Chinawill mainly focus on two projects: efficient control and energy saving andenvironmental protection. [12] Under this background, improving the effectiveapplication level of new energy automobile air conditioning system will becomea key research direction. How to effectively reduce the energy consumption ofair conditioning system in the use process and break through the existingefficiency conversion value on this basis has become the focus of currentresearch work. In-depth study of heat pump air conditioning system technologyand fuel cell waste heat utilization technology, and on this basis, combinedwith the actual needs of the integration of new energy vehicles, select a newenergy vehicle air conditioning system technology that meets the standards.[13] With the development of society, electric vehicles with new energy usemotors as power devices of air-conditioning system, which has great room forimprovement in control. It can realize more intelligent and efficient controlsystem. Frequency conversion, hot refrigeration and other technologies areexpected to be widely used. [14]

2. 研究的基本内容与方案

Fuel cell vehicles are the trend of thedevelopment of the whole automotive industry at this stage. The vigorousdevelopment of new energy automotive air conditioning system will play animportant role in promoting the development and promotion of new energyautomobiles. A fuel cell bus air conditioning system is designed for the newenergy vehicle air conditioning system, which uses power battery as powersupply and consumes large energy in winter heating system. The main contents ofthis paper are as follows:

1)Reading relevant literature, collectingrelevant literature on fuel cell bus air-conditioning system by scholars athome and abroad, and investigating and analyzing the current research situationof bus air-conditioning system, providing guidance for theoretical research,design and analysis of fuel cell vehicle air-conditioning system in thispaper.