For those who are looking for future automotive research and development topics, some professionals recommend the research direction of heaters for electric vehicles. The small edition gives you why the performance of electric vehicles depends on the heater.
The reason for this is that the use of cold and warm air conditioning in electric vehicles will lead to a significant decline in the range. Especially when using heating and air conditioning, it consumes more electricity. In the past, gasoline vehicles can use the waste heat of engines, so heating only needs a very small amount of electricity compared with refrigeration, but the waste heat of electric vehicles is less (the temperature is also lower), so it is a headache that the energy of rechargeable batteries is consumed by heaters when heating.
At present, most electric vehicles use PTC (Positive Temperature Coefficient) heaters. For example, Mitsubishi’s “i-MiEV” uses PTC heater to heat circulating water, and Nissan’s “Leaf” will be launched in 2010 to heat air directly through PTC heater. Later, Nissan’s air heater was understood to have undergone considerable changes, or abandoned, to use point-to-point, face-to-face heating.
Today, the types of electric vehicle heaters have become diverse, and there are the most patterns abroad. For example, Ebech PTC water heater in Germany has good performance, very compact, high space utilization rate and good heating effect. Using PTC heating technology, PTC has good characteristics of self-control temperature, self-constant temperature and self-saving energy. For example, German Weibo Stone uses natural gas combustion to heat the antifreeze in the chamber to realize liquid heating. For example, Cummins nickel-chromium wire water heater in the United States uses nickel-chromium wire as heating unit to heat antifreeze and complete instant heating cycle. The cost of the water heater is half of that of PTC water heater.
Although many foreign automotive heater giants choose different materials, they basically determine one, that is, the ultimate ideal answer is the water heater.
PTC air heater has several obvious shortcomings:
1. It is a very contradictory topic that the location of PTC is not good. The PTC is ceramic and solid in appearance, and its size is fixed. Using this heater, it is necessary to install it in the air duct of the air conditioning assembly, and the space here is very limited. Therefore, the air conditioning assembly of most existing models can only be used in general. Place an air heater of about 2KW. But in winter, 2KW can not meet the defrosting requirements. Of course, we can re-open the mould, reconstruct the air-conditioning assembly, and continue to expand the power.
2. Safety hazards, generally in winter, the temperature of air outlet of air conditioning assembly is above 50 degrees, so the surface temperature of PTC air heater needs to be close to more than one hundred and close to two Baidu, so there are two safety hazards, one is the fan stops running, the other is the high caused by continuous dry burning of heater when the temperature controller fails. Temperature will melt the air duct. This kind of accident really exists in reality.
However, the air heater in fact has a large domestic market, almost the vast majority of large automobile manufacturers choose PTC air heater, because there is no water heater in China, can only be purchased from abroad, the unit price is tens of thousands of times, this is to strive to strictly control the cost, will electric vehicles landing domestic automobile manufacturers do not want to see. How much is a car?