The plate heat exchanger is composed of a group of corrugated metal plates. The plate has four corner holes for the heat transfer of two liquids, and guides the fluid to flow through their respective channels for heat exchange. The plates are closely arranged, with high precision, small volume, high heat exchange efficiency, space saving, high environment requirements, suitable for use on small refrigeration units. General air-conditioning equipment can be used for 15-20 years under normal maintenance conditions. Why are the plates of plate heat exchangers broken down? Today we analyze the following three points for you:
1. Construction problem: Only filters are installed in the system, and no electronic water treatment device is installed, so it is difficult to ensure that the pipeline system is not fouled. In addition, if the filter is not cleaned in time, there will be small grit remaining in the circulating water, even if it is basically not harmful to the shell-and-tube heat exchanger, but it will cause damage to the plate heat exchanger plate.
2. Quality problem: Compared with the heat exchange surface of other heat exchangers, the heat exchange surface of the plate heat exchanger plate is quite thin, namely 0.5mm, and the allowable corrosion degree is 0.05mm/year. The material of ordinary plate heat exchanger is usually alloy material (304 or 316). 304 is the cheapest kind of austenitic stainless steel. It has anti-corrosion ability to a certain range of organic matter, but weak resistance to hydrochloric acid and sulfuric acid. The material of the plate heat exchanger of the air conditioner is 304. After 8 years, the plate will break down and corrode.
3. Maintenance issues: Plate heat exchangers are an important component of heat exchange skills in process industrial equipment. The plate heat exchanger gasket that seals between the various plate fins is a wearing part, and is also a part that is prone to aging under natural conditions. Its service life has an important influence on the service life of the plate heat exchanger. If these seals are hardened and lose their original elasticity, and if they are re-tightened or replaced in time, they can cause the heat exchanger to appear as a drip. After long-term operation, the plate heat exchanger needs to be cleaned regularly, usually once every two years. Today's plate heat exchangers can be disassembled and cleaned individually, but some plate heat exchangers cannot be disassembled. They can only be cleaned by opening the valves and plugs on the inlet and outlet pipes of the heat exchanger. Therefore, the heat exchanger is difficult to clean and clean, and it simply blocks and scales. Once a part of the channels in the heat exchanger are blocked, other channels have to accept the flow rate of all the water in the unit. In this way, the flow rate through the plate heat exchanger As it increases, friction increases, and wear increases immediately.