The internal fluorine-water heat exchanger of the water system air-conditioning host plays the role of heat exchange with the auxiliary refrigerant. There are usually three types of heat exchangers: double-tube heat exchangers, shell-and-tube heat exchangers and plate heat exchangers. The first two are used for large-scale units. The advantages are small pressure loss, low water quality requirements, and not easy to block. The water-water plate heat exchanger is used in small units, and has the advantages of small size and high efficiency. The water system host must have a heat exchanger, and the water-water plate heat exchanger is a better choice. With the long use time and the influence of the use environment, the heat exchanger will gradually appear corrosion problems. So what are the parts that are prone to corrosion?
(1) Corrosion of heat exchanger shell
If the medium in the shell is an electrolyte and the material is carbon steel, and the tube bundle baffle is made of copper alloy, it is easy to corrode. If the welding quality of the shell and accessories is too poor, the water-to-water plate heat exchanger is prone to corrosion.
(2) Corrosion of heat exchange tube
Dirt in the medium and eddy current wear in the inlet medium can cause pipeline corrosion, especially the front inlet is prone to corrosion. This is mainly because the fluid and dead ends are prone to vortex agitation.
(3) The joints between the baffle, the pipe and the tube sheet are prone to joint corrosion
The joints between the heat exchange tube and the tube sheet of the heat exchanger and between the heat exchange tube and the baffle are easily broken in the expansion tube. When there is a gap between the tube sheet and the tube, cl accumulation and oxygen concentration will occur, which will cause corrosion on the surface or gap of the heat exchange tube. The main cause of corrosion of water-water plate heat exchangers is that most heat exchange equipment uses water for heat exchange. As the temperature rises, certain salts will crystallize and adhere to the surface to form scale.