Operation principle
Reverse Carnot cycle:
Through the four major components of compressor, evaporator, condenser and expansion valve, heat is transferred from low-temperature air to high-temperature drying medium.
- Heat absorption: The evaporator absorbs low-temperature heat from the ambient air.
- Heat release: The condenser releases high-temperature heat into the drying box, heating the air and reducing humidity.
Dehumidification and drying:
When the hot and humid air passes through the condenser, the moisture condenses and is discharged (dew point dehumidification), and the latent heat is recovered at the same time, and the energy efficiency ratio (COP) can reach 3-5.
Core components
Compressor
Drives the refrigerant circulation and increases the heat temperature (commonly used scroll/screw type).
Evaporator
Absorbs heat from the ambient air, and the refrigerant evaporates into low-temperature gas.
Condenser
High-temperature refrigerant releases heat to heat and dry the air.
Expansion valve
Throttles and reduces pressure to adjust the refrigerant flow.
Drying box/air duct
Carries the dried material and forces hot air circulation.
Dehumidification system
Condensation dehumidification + heat recovery to reduce the humidity of the drying air.
Control system
Adjusts temperature (40-80℃), humidity, wind speed, and supports intelligent operation (such as PLC/Internet of Things)
Advantages vs. Traditional Drying
| Comparison | Heat Pump Dryer | Coal/Electric Dryer |
| Energy Use | COP≥3, >60% energy savings | Low efficiency, high consumption |
| Temp. Control | ±1°C precision | ±5°C or worse |
| Eco-Friendliness | Zero Emissions | Coal emits SO₂/dust |
| Automation | Smart humidity control, remote monitoring | Manual operation |
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