The plate heat exchanger is an important accessory on the refrigeration mainframe.It is a combination of a set of corrugated metal plates with four corner holes for the two liquids for heat transfer to guide the fluid to alternately flow through the respective channels for heat exchange.They are closely arranged, high precision, small in size, high in heat exchange efficiency, space saving, and high in use environment, suitable for use on small refrigeration units. Generally, air-conditioning equipment can be used for 15 to 20 years under normal maintenance and repair conditions, but the reasons for the breakdown of the plate heat exchanger are as follows:
1. Plate heat exchanger quality problem
Compared with the heat exchange surfaces of other heat exchangers, the heat exchange surface of the plate heat exchanger is quite thin (0.5 mm), and the maximum corrosion degree allowed is 0.05 mm/year.
Ordinary plate heat exchangers are usually made of alloy material (304 or 316). 304 is the cheapest of austenitic stainless steels. It has anti-corrosion ability to a certain range of organic substances, but is weak against hydrochloric acid and sulfuric acid.The plate heat exchanger of the air-conditioner is made of 316. After 8 years, it will be inevitable that the plate will penetrate and corrode.
2. Plate heat exchanger maintenance problem
Plate heat exchangers are an important part of heat exchange technology in process industry equipment. The elastic gasket that seals between the various plate fins is a consumable part and is also an easily aging part under natural conditions. If these seals harden, they lose their original elasticity. If it is not retightened or replaced in time, it may cause dripping in the heat exchanger.In addition, the plate heat exchanger needs to be cleaned regularly (cleaned once every two years) after a long period of operation.
The current plate heat exchanger can be disassembled to clean the pieces separately, but some plate heat exchangers cannot be disassembled.It can only be cleaned by opening the valve and wire plug on the inlet and outlet pipes of the heat exchanger, so the heat exchanger is difficult to clean and it is easy to block and scale.Once a part of the passage in the heat exchanger is blocked, the remaining passages have to withstand the flow of all the water in the unit, so that the flow rate through the plate heat exchanger increases, the friction increases, and the wear is accelerated.