Plate heat exchanger is a kind of heat exchanger formed by pressing thin metal plates into heat exchange plates with a certain corrugated shape, then stacking them and fastening them with frame plates and bolts. The working fluid flows through the narrow and tortuous channel formed between the two plates. The hot and cold fluids pass through the flow channel in sequence, and there is an interlayer plate in the middle to separate the fluids and exchange heat through the plates. There are four types of failures in the use of plate heat exchangers.
(1) The external leakage of the plate heat exchanger is mainly leakage (small volume, discontinuous water droplets) and leakage (large volume, continuous water droplets). The main parts where leakage occurs are the seal between the plate and the plate, the two sealing leak grooves of the plate, and the inner side of the end plate and the compression plate.
(2) The string liquid of the plate heat exchanger is mainly the medium on the higher pressure side stringing into the medium on the lower pressure side. Abnormal pressure and temperature will occur in the system. If the medium is corrosive, it may also cause corrosion of the gasket of the plate heat exchanger. Liquid leakage usually occurs in the diversion area or the second sealing area
(3) The pressure drop of the heat exchanger is large. The medium inlet and outlet pressure drops exceed the design requirements, or are many times higher than the design value, which seriously affects the system's requirements for flow and temperature. If the pressure drop on the hot side is too large in the heating system, the primary side flow will be seriously insufficient.
(4) The heating temperature cannot meet the requirements. The main feature is that the outlet temperature is low, which fails to meet the design requirements.