What are the common failures of heat exchangers?

1. Leakage
Leakage is one of the most common failures of heat exchangers, which is mainly manifested by system pressure drop, loss of coolant or heating medium, which seriously affects the heat exchange effect.
External leakage: The main reasons are dislocation, separation from the sealing groove, damage or aging of the sealing gasket, corrosion and deformation of the plate, uneven or inadequate clamping size, loose clamping bolts, etc.
Internal leakage: The main reasons are aging or damage of the sealing gasket and corrosion and perforation of the plate.
Leakage between the blind plate and the clamping plate: The main reason is that the blind plate is pierced by a hard object.
2. Abnormal pressure drop
Abnormal pressure drop is usually manifested as a pressure drop greater than the design value. Possible reasons include:
The actual flow rate is greater than the design value.
The channel between the plates is blocked.
The entrance of the plate corner hole is blocked.
3. Abnormal heat exchange temperature
Abnormal heat exchange temperature will affect the heat exchange efficiency of the heat exchanger, which is specifically manifested as follows:
The hot side outlet temperature is too high: Possible reasons include too small selection, insufficient heat exchange area, hot side flow greater than the design value, plate scaling, plate blockage or low cold side flow.
The cold side outlet temperature is too low: Possible reasons include low hot side flow or temperature lower than the design value, plate scaling, and plate blockage.
4. Scaling and blockage
Scaling and blockage will seriously affect the heat exchange efficiency of the heat exchanger and lead to energy waste.
Scaling: Inorganic salts dissolved in water in the pipeline crystallize and precipitate, forming scale on the wall of the heat exchange surface such as the condenser, resulting in reduced heat exchange efficiency.
Blockage: Due to the formation of dirt by mud, silt, and humus in the water, coupled with the biological slime formed by bacteria, algae and other microorganisms and their secretions, the pipeline is blocked in severe cases.
5. Corrosion
Corrosion is one of the common failures of heat exchangers. The main reasons are:
The water quality is too acidic or there are too many chemicals in the water.
Lack of effective water treatment measures.
The heat exchanger material itself has defects.
6. Mechanical failure
Mechanical failures come in various forms, including but not limited to metal corrosion, steam or water hammer, thermal expansion and circulation.
Troubleshooting methods
For the above faults, the following troubleshooting methods can be adopted:
Leakage: Check whether the seal is aged or damaged, and replace it if necessary; check whether the connection is loose, and re-tighten it if necessary.
Abnormal pressure drop: Clean the blocked channel to ensure smooth fluid flow.
Abnormal heat exchange temperature: Clean the scale to ensure the cleanliness of the heat exchange surface; check whether the flow meets the design requirements.
Scaling and blockage: Perform chemical cleaning or jet cleaning regularly to remove scale.
Corrosion: Select corrosion-resistant pipes, add corrosion inhibitors, and control the flow rate in the pipe.
Mechanical failure: Check whether the mechanical parts are loose or worn, and replace or reinforce them if necessary.