Principle of automobile air conditioning condenser
I. Working principle of condenser
The condenser is integrated into the front-end module of the whole vehicle and placed at the front end of the vehicle. It is part of the air conditioning system. The condenser transfers the energy of the refrigerant to the surrounding environment, turning the high-temperature and high-pressure refrigerant vapor into a high-temperature and high-pressure refrigerant liquid.
II. Classification of condensers
(1) Tube-sheet type (fin-tube type)
Although the heat exchange efficiency of the tube-sheet type structure is poor, it has a simple structure and low processing cost. After structural improvements, the heat exchange efficiency has also been improved, so it is still widely used. Medium and large automobile air conditioners currently mainly use the tube-sheet type structure.
(2) Tube-belt type
The tube-belt type is welded by a porous flat tube and an S-shaped heat dissipation belt. The heat dissipation effect of the tube-belt condenser is better than that of the tube-fin condenser (generally about 10% higher), but the process is complicated, welding is difficult, and the material requirements are high. It is generally used in the refrigeration device of small cars.
(3) Eel (& fin) plate type
It is to directly sharpen the eel-shaped heat sink on the surface of the flat multi-pass pipe, and then assemble it into a condenser, as shown in the figure. Since the heat sink eel plate and the tube are a whole, there is no contact thermal resistance, so the heat dissipation performance is good; in addition, there is no need for complex welding between the tube and the plate. The connection process has good processability, saves materials, and has excellent vibration resistance. Therefore, it is currently the most advanced automotive air conditioning condenser.
(4) Horizontal flow type
It evolved from the tube belt type and is also composed of flat tubes and heat sinks. The heat sink also has louvered slits, but the flat tubes are not bent into a snake shape, but each one is cut off. There is a header at each end. The refrigerant enters the cylindrical or square header from the pipe joint, and then flows into the elliptical flat tube, flows in parallel to the opposite header, and finally returns through the jumper tube. to the pipe joint seat or another pipe joint.
Through test comparison, the horizontal flow type has a great advantage and is also the main form in the market. But the horizontal flow type is divided into two types, supercooling and non-supercooling.
During the design process, the supercooling type integrates the connecting pipes between the liquid storage tank and the compressor to fully supercool the high-temperature and high-pressure gaseous refrigerant from the compressor. Reduce the volume and weight occupied by the car air conditioner. According to the test, the cooling capacity of the supercooling system can be increased by 5%. At the same time, because of the good cooling effect, the compressor displacement can be reduced to save engine power. At the same time, as an integrated structure; the supercooling condenser is also very convenient in vehicle installation, so it is widely used.
3. Surface treatment of the condenser
Because the condenser is arranged at the front of the car, dust, mud, sand and stones splash onto the condenser, reducing the heat return capacity, acidic substances corrode, and it is easy to rot; anti-glare measures must be taken at the front of the car.
Solution: anti-corrosion and anti-glare (anodized black and black matte paint) treatment, regular cleaning.
