Because the heat of hot air is obtained from the coolant. This is not the same as refrigeration. Cold air is obtained by a compressor. The engine must be assisted by a good cooling system when working. The temperature of the combustion chamber in the cylinder is as high as several thousand degrees. If the heat is not released in time, the engine will explode soon.
Air-cooling means that the engine block has fins to dissipate heat. Liquid cooling is the most commonly used cooling method for automobiles at present. Waterways are reserved at high temperature positions such as engine cylinder liner and cylinder head, and coolant flows in the waterways. The cylinder head and the like are like a boiler, constantly heating the coolant in the interlayer to complete the heat dissipation.
First of all, heating warm air in winter will consume the heat of the engine. If the displacement of the engine is relatively small, it is easy for you to say this. Because the heat generated by engine operation is not enough to offset the heat consumed by heating air, it is normal that the water temperature will drop when heating air. If it is a large displacement engine, or when driving at high speed, this problem will not occur.
This situation will only occur when the warm air is turned on under the condition of small displacement+low temperature+low speed driving. This is a normal phenomenon, don't worry. This phenomenon generally does not exist because the temperature of the water tank and the temperature of the heater are two different things. The heater uses the heat energy emitted by the water tank. You should check whether the water pipes in the two water tanks are clear.
Check your power supply system, generator, generator regulator and battery. This is a symptom of low voltage, which is called power failure in jargon. On the other hand, if the displacement of the engine is small and the rotational speed is in a low speed state for a long time, the heat transferred from the engine coolant to the heater core may be less than the heat taken away by the blower.
Then, the temperature of the coolant will gradually decrease, and we will see that the pointer will gradually decrease when it is reflected on the water thermometer. Put it down and it will reach about 60C. So driving in winter, we may see the water temperature drop, which is normal. At this time, the water temperature only tends to the lower limit. As long as we refuel and speed up, the water temperature will gradually return to normal level.
Extended data:
Working principle of heater:
Electric heating heater is a kind of energy-consuming heater that converts electric energy into heat energy to heat the material to be heated.
When working, the low-temperature fluid medium enters its input port through the pipeline under pressure, and takes away the high-temperature heat energy generated when the electric heating element works along the specific heat exchange channel in the electric heating container by using the path designed by the principle of fluid thermodynamics, so as to raise the temperature of the heated medium and obtain the high-temperature medium required by the process at the outlet of the electric heater.
The internal control system of the electric heater automatically adjusts the output power of the electric heater according to the signal of the temperature sensor at the outlet, so that the temperature of the medium at the outlet is uniform; When the heating element overtemperature, the independent overheating protection device of the heating element immediately cuts off the heating power supply, so as to prevent the heating material from coking, deterioration and carbonization due to overtemperature, and even lead to the burning of the heating element in severe cases, thus effectively prolonging the service life of the electric heater.
Baidu encyclopedia-electric heater