Today's cars are basically equipped with cooling and heating as standard, which can be both cooled and heated. Refrigeration is relatively simple, press the AC button on the air conditioning panel, as long as the engine is running, there will be cold air. If there is a hot air, the situation will be different. When the car is in a cold start state, you need to wait for a while until the hot air comes out. About 2 to 5 minutes. The reason is that the heating of the air conditioner is now heated by using the heat of the engine cooling water, and if the water temperature does not rise, the hot air will not come out. The headline says that mercedes-benz starts cold at minus 5 degrees, the water temperature is still 0, but soon there will be hot air. I wonder if this is something wrong with the car or if Mercedes has some high-tech. I'll answer one. Is there no quality problem with the car?
Theoretically, even if this happens, the probability of a quality problem is low. The method of judging is simple. After the water temperature rises, adjust the temperature of the air outlet. If the temperature of the air outlet can be adjusted normally, the air conditioning hot air system is normal. Why does hot air appear after Mercedes-Benz starts? At present, there are only three sources of hot air in automobiles. One is a very common engine exhaust heating air conditioning heating system, the second is the PTC electric resistance wire heating air conditioning system, and the third is the heat pump air conditioning system. Engine exhaust heating air conditioning heating system is very common, from the top to tens of millions of Rolls-Royce, from the bottom to thirty thousand Wuling Hongguang all use this. In summary, the principle is to use the waste heat of the engine for heating. As shown in the figure, running the engine at high speed generates a lot of heat. At this time, the coolant flowing through the engine's hot water channel absorbs this heat, and the cooling grille sent to the front of the car is air-cooled or the fan is started for heat dissipation. When heating is required, after any valve is opened, the high-temperature coolant flows into the heater core, the heater core heats up, and the high-temperature air is blown into the interior of the car room through the blower, generating hot air.
PTC thermal resistance line heating air conditioning system, the principle is simpler. PTC heater, also known as PTC heater, is an abbreviation for English Positive Temperature Coefficient, which consists of PTC ceramic heating parts and aluminum tubes. When used, by energizing the PTC thermistor to heat up its own heat, the resistance value enters the transition area, and the surface temperature of the PTC thermistor is maintained by constant temperature heating, and the high temperature PTC heating body burns the surrounding air, so that the air temperature rises, and the blown wind becomes hot air. Now, most electric vehicles without engines use PTC thermal air conditioners. The structure is simple and the quality is stable. The disadvantage is that the energy consumption is high, the peak power is between 4 and 6kw, and the impact on the endurance distance is very large.
Heat pump air conditioning is a relatively economical air conditioning system, which does not require the waste heat of the engine and does not require PTC heating. On the basis of ordinary air conditioning, install a four-way reversing valve, change the operation of the valve, you can replace the function of the original air conditioner evaporator and condenser, the function of cooling indoor air into the function of heating indoor air. In the case of minus 5 degrees, hot air will appear immediately after working together, which is the air conditioning heating system used by Mercedes-Benz in combination with the exhaust air conditioning PTC heating. After the vehicle starts and the driver emits hot air, the Mercedes-Benz begins PTC resistance heating, heating the surrounding air and blowing out hot air. Earlier models of the Mercedes-Benz e-Class, such as the Model 19 Mercedes-Benz E 260 and the new Model 2022 260, combined a 48V light hybrid system for fuel consumption.
The light hybrid system is a P0 class weak hybrid system, the electric motor is directly connected to the transmission, the ISG is integrated into the electric motor, and it is configured between the engine and the transmission. From the surface parameters, the maximum output power and torque of the new ISG motor has increased from 10kW/160Nm of the BSG motor to 15kW/200Nm. That is to say, this light hybrid motor can increase the power supply by up to 15kw. If there is a power supply, the driving car can achieve "air conditioning freedom", even if the engine is not started, it can temporarily maintain the refrigeration of the air conditioning compressor, or when the engine water temperature is low, the engine turns the motor to generate electricity, and the PTC power supply heating If the temperature of the engine rises, Mercedes-Benz will reduce the power of the PTC heat pipe and draw heat from the engine. Due to the continuous development of the technology of Mercedes-Benz engines, especially Mercedes-Benz E-class engines, both the obsolete 264 engine and the latest 265 engines have adopted integrated covers.
Cylinder head is currently the mainstream technology, which can improve the engine warm-up speed, reduce heat loss, and raise the engine temperature to the optimal condition as soon as possible, thereby reducing fuel consumption and vibration. Therefore, the speed of engine preheating of Mercedes-Benz in the case of extremely low temperatures is also relatively fast, and it can be used as soon as possible to blow out warm air with waste heating, replacing PTC heating seamlessly. After all, the reason why the Mercedes-Benz car can blow out hot air when it starts the engine together at extremely low temperatures is to add a PTC heating system to the Mercedes-Benz car to make up for the problem of low water temperature and no warm air. Other cars can't do it because they don't have this PTC heating system. For Mercedes-Benz, the price is high and the positioning is luxurious, and it must be positioned and differentiated in these details in order to show a sense of luxury