What is the reason for car air conditioning not cooling?
For the air conditioning of automobiles, the most common problem we encounter is that after one winter, when the air conditioner is turned on, it is found that the cooling capacity of the air conditioner has decreased; even some air conditioner outlets of the vehicle will blow hot air. What is the reason for car air conditioning not cooling? What if the car air conditioner is not cooling?
The reason why the car air conditioner does not cool
Automobile air conditioners are not cooled. The phenomenon of insufficient air conditioning and sometimes no refrigeration is caused by the refrigeration system. In addition to requiring the maintenance workers to have a good diagnostic thinking and methods, the maintenance process also requires maintenance. Careful and meticulous can completely and completely eliminate the fault. Nowadays, cars are basically equipped with air conditioners, which provide drivers with a comfortable environment in different seasons, but when the air conditioners work for a long time, various faults will occur, especially This phenomenon of insufficient cooling is also more common, so today I would like to discuss with you the principle of automobile air conditioning and the cause of failure and maintenance of insufficient cooling. Before we understand the reasons for the non-refrigeration of automotive air conditioners, let us first understand the working principle of the air conditioning refrigeration system and the composition and function of the air conditioning system!
The car air conditioning system is referred to as the car air conditioning system. The main purpose is to provide a comfortable interior environment for the occupants in any climate and driving conditions. People's environmental requirements are often different due to physical fitness, age, gender, habits and health. But under normal circumstances, the requirements of most people are still roughly the same. The right temperature, the right humidity, the right air flow and the clean air form the three elements of air conditioning: temperature, humidity and cleanliness. A complete automotive air conditioning system achieves the goal of creating a comfortable environment in the cabin by adjusting temperature, humidity, wind speed and ventilation.
First, the general composition and function of automotive air conditioning systems, air conditioning systems generally consist of the following five systems:
(1) Refrigeration system: Cooling or dehumidifying the indoor air or the fresh air entering the vehicle interior from the outside to make the indoor air cool and comfortable.
(2) Heating air system: It is mainly used for heating, heating the indoor air of the vehicle or the fresh air entering the vehicle interior from the outside to achieve the purpose of heating and dehumidification.
(3) Ventilation system: The external fresh air is sucked into the cabin to provide ventilation and ventilation. At the same time, ventilation also plays a good role in preventing fogging of the windshield.
(4) Air purification system: removes dust, odor, smoke and toxic gases from the air inside the vehicle to make the indoor air clean. System: Controls the temperature and pressure of the refrigeration and heating system, and controls the temperature, air volume and flow direction of the air in the vehicle, and improves the normal operation of the air conditioning system.
Second, the working principle of automotive air conditioning refrigeration system
(I) Working principle of automotive air conditioning refrigeration system The automotive air conditioning refrigeration system consists of a compressor, a condenser, a liquid storage dryer, an expansion valve, an evaporator and a blower. As shown in Figure 1, copper pipes (or aluminum pipes) and high-pressure rubber pipes are connected between the components to form a closed system. When the refrigeration system is working, the different states of the refrigeration memory circulate in this closed system, and each cycle has four basic processes:
1. Compression process: The compressor sucks the low-temperature refrigerant gas at the outlet of the evaporator and compresses it into a high-temperature and high-pressure gas-exhausting compressor.
2. Exothermic process: The high temperature and high pressure superheated refrigerant gas enters the condenser. Due to the pressure and temperature decrease, the refrigerant gas condenses into a liquid and releases a large amount of heat.
3. Throttling process: After the refrigerant liquid with higher temperature and pressure passes through the expansion device, the volume becomes larger, the pressure and temperature drop sharply, and the expansion device is eliminated by mist (fine droplets).
4. Endothermic process: The misty refrigerant liquid enters the evaporator, so the boiling point of the refrigerant is much lower than the temperature inside the evaporator, so the refrigerant liquid evaporates into a gas. The surrounding heat is absorbed in a large amount during the evaporation process, and then the low-temperature low-pressure refrigerant vapor enters the compressor again.
The above process can be carried out repeatedly to achieve the purpose of reducing the temperature of the air around the evaporator.
The lack of refrigeration or air-conditioning of automobile air conditioners is a common fault of air conditioners. The basic maintenance methods can be mastered by general maintenance workers, that is, starting from an easy part and finding the cause or part through eye-viewing, called sensory inspection. Another method of detection, the meter detection method, is easily overlooked. This method can often help to find the cause of the fault accurately and quickly.