During the application period, the plate-type heat exchanger unit will cause equipment failure, affect the heat exchange efficiency, and the use effect and service life due to various factors. So, what are the reasons for the decrease in the heat exchange efficiency of the plate-type heat exchanger unit?
Material and structural factors
Wrong material choice: If the material selection for the plate heat exchanger is improper, such as using materials with a smaller heat transfer coefficient, it will affect the overall heat transfer performance of the heat exchanger. The thermal resistance of the material is large, resulting in a decrease in the efficiency of heat transfer, thereby affecting the heat transfer efficiency.
The structure is not reasonable: if there are design defects in the structure of the plate-type heat exchanger, such as the cold and hot sources cannot fully contact the heat exchange area, it will cause large local temperature differences and the heat exchange area cannot be fully utilized. The heat transfer is uneven, resulting in a decrease in overall heat exchange efficiency.
Fluid factors
Low flow rate or blockage: a low flow rate on one side of the fluid will cause the boundary layer of the fluid on the wall to be too thick, affecting heat transfer. At the same time, particles in the fluid may block the channel of the plate, reducing the fluid flow rate. The heat transfer rate decreases, and the heat transfer efficiency decreases.
Scaling: Impurities in the fluid may deposit on the surface of the plates, forming a scale layer. The scale layer has poor thermal conductivity, which hinders heat transfer, leading to a decrease in the efficiency of heat exchange.
Sealing and Leakage
Gasket aging or damage: After long-term operation, the gasket of the plate heat exchanger may fail due to aging, damage, or detachment. Fluid leakage occurs, resulting in a decrease in heat transfer efficiency, and at the same time, it is possible that the medium mixing affects the normal operation of the system.
Blade deformation or misalignment: The blades may deform or misalign due to accidental impact or improper operation. This destroys the seal, leading to fluid leakage and affecting the heat exchange efficiency.
Changes in Operating Conditions
Temperature difference decrease: The temperature difference between the heat source and the cold source decreases, and the driving force for heat transfer weakens.
Flow rate change: a change in the fluid flow rate, such as a reduction in flow rate, will result in a decrease in the heat transferred through the heat exchanger plate per unit time.
Improper maintenance
Failure to clean in time: After long-term operation, the surface of the plate-type heat exchanger may scale or adhere to impurities. If not cleaned in time, the scale layer and impurities will hinder the heat transfer, resulting in a decrease in heat exchange efficiency.
Maintenance not up to standard: such as not replacing the gasket in time, not repairing the plates thoroughly, etc. The equipment performance gradually declines, and the heat exchange efficiency decreases.
To sum up, the reasons for the decrease in the heat transfer efficiency of the plate-type heat exchanger unit may involve material and structure, fluid, seal and leakage, operating conditions, maintenance and many other aspects. To improve the heat transfer efficiency, it is necessary to start from the design, selection, operation, maintenance and other links, and implement comprehensive measures. For example, select appropriate material and structure, optimize fluid flow rate and flow, strengthen seal and leakage management, clean and maintain equipment regularly, etc.