Key Features and Functionality
- Hot gas bypass process: High-temperature, high-pressure discharge gas from the compressor is diverted directly to the evaporator, skipping other system components.
- Temperature elevation: Discharge gas, typically at 60–80 °C, heats the evaporator, enabling rapid frost removal.
System Components
- Bypass piping with solenoid valve:
- Installed at the compressor outlet.
- Regulates gas flow to the evaporator.
- Solenoid valve control:
- Operated via thermostat, timer, electronic controller, or similar devices.
- Hot gas flow:
- Travels from evaporator back to the compressor through dedicated piping.
- Phase change:
- Interaction with low-temperature zones in the evaporator may cause the gas to transition from superheated vapor to saturated liquid.
Protective Measures
- Liquid accumulator: Prevents liquid refrigerant from reaching the compressor, avoiding potential damage.
- KVL valve: Installed before the compressor to prevent excessive suction pressure.
Advantages of the System
- Rapid defrosting: Efficiently removes frost buildup.
- Continuous compressor operation: No need to shut down during the defrost cycle, ideal for high-capacity systems.
Optimization and Control
- Hot gas flow regulation:
- A control valve in the bypass line ensures proper gas distribution, avoiding evaporator flooding.
- System enhancements:
- While the basic setup illustrates functionality, additional components improve defrosting performance and compressor longevity.
- Automatic activation:
- Defrost begins automatically when triggered by a thermostat or programmed schedule, without interrupting compressor operation.
Applications
- High-capacity systems:
- Particularly useful in industrial and commercial applications where compressor shutdown is impractical.
Summary
The hot gas bypass defrosting system offers an efficient solution for frost removal while maintaining continuous compressor operation. Its reliability and effectiveness make it an excellent choice for demanding industrial and commercial refrigeration systems.
