There are many types of heat exchangers, and the operation methods are similar. The common point is that they use a large amount of contact area between the two materials for heat exchange to complete chemical processes such as cooling, condensation, heating and evaporation. The operating conditions of the heat exchanger, the nature of the heat exchange medium, the corrosion rate and the operating cycle determine the maintenance and management of the heat exchanger. The widely used shell-and-tube heat exchanger (pipe-and-tube heat exchanger) is taken as an example to discuss its maintenance management method.
1. Startup of heat exchanger
(1) Firstly use the connecting pipe attached to the casing to completely remove the gas and condensate in the heat exchanger (if the fluid is steam) to avoid water hammering, and then open the exhaust valve.
(2) Pass the cryogenic fluid first, and close the bleed valve when the liquid fills the heat exchanger.
(3) Slowly pass the high-temperature fluid to avoid thermal shock caused by rapid fluid flow due to large temperature difference.
(4) During the temperature rise to the normal operating temperature, the external connecting bolts should be retightened to prevent the gasket from leaking tightly.