Common Faults of Plate Heat Exchangers

1. External Leakage

Manifestation:

· Seepage: Small-scale leakage with discontinuous water droplets.

· Leakage: Larger-scale leakage with continuous water droplets.
Common Locations:

· Sealing joints between heat transfer plates.

· Secondary sealing leakage grooves on the plates.

· Inner surface of the end plate and the contact area with the pressure plate.

2. Cross-Contamination (Fluid Mixing)

Manifestation:

· Medium from the high-pressure side flows into the low-pressure side, causing abnormal pressure and temperature in the system.

· If the medium is corrosive, it may corrode the sealing gaskets of the heat exchanger.
Common Locations:

· Flow guiding areas where fluid distribution occurs.

· Secondary sealing zones designed to prevent cross-flow.

3. Excessive Pressure Drop

Manifestation:

· The pressure difference between the inlet and outlet of the medium exceeds the design specification, often by multiple times, severely affecting the system’s flow and temperature requirements.

· In heating systems, a large pressure drop on the hot side can lead to insufficient primary-side flow (inadequate heat source), resulting in the secondary-side outlet temperature failing to meet requirements.

4. Inadequate Heating Temperature

Manifestation:

· The outlet temperature of the medium is lower than the design value, failing to achieve the required heating effect.

These faults often result from gasket aging, misalignment, plate fouling, improper installation, or uneven tightening of bolts. Regular maintenance, including cleaning, gasket inspection, and torque control during assembly, can effectively reduce the occurrence of such issues.