Application of heat pump dryer in drying industry

The heat pump dryer mainly consists of fin evaporator, compressor, fin condenser and shrinkage valve. Its working principle is the same as that of the refrigeratory. It works according to the reverse Carnot cycle. The difference is that the operating temperature range is different. Heat pump technology emerges in an endless stream, and its use is constantly expanding. It is widely used in air conditioning and industrial fields, and plays an important role in energy saving and environmental protection. Drying is an important process in many industrial production and agricultural processing processes. With the development of national economy, the awareness of environmental protection is gradually deepening. In most developed countries, the energy consumed for drying accounts for 7% - 15% of the total energy consumption, while the thermal efficiency is only 25% - 50%, and most drying processes, especially for heat sensitive materials, will affect their color, nutrition, flavor and organization.

By allowing the working medium to complete the thermal cycle of evaporation (absorbing heat from outdoor environment) compaction_condensation_throttling_re-evaporation from time to time, the heat in the external low temperature environment is transferred to the drying room, and the refrigerant circulates in the system under the action of the compressor. In the future, heat pump dryer will play an important role in the new industrial civilization. It completes the gaseous pressurization and heating process in the compressor (the temperature is as high as 100 C). It enters the internal machine and releases high-temperature heat to heat the air in the drying room. At the same time, it is cooled and converted into liquid. When it runs to the external machine, the liquid rapid endothermic evaporation is transformed into gaseous again. At the same time, the temperature can drop to - 20 C to - 30 C. At this time, the air around the heat absorber will come from time to time. The ground conveys heat to the refrigerant.