Multistage heating and multistage tempering drying type airflow open-cycle heat pump drying system

Abstract

The invention provides a multistage heating and multistage tempering drying type airflow open-cycle heat pump drying system. The system comprises a drying portion, a heat pump system used for generating a drying medium, and an inflowing channel and an outflowing channel which communicate with the drying portion; the drying medium flows into the drying portion through the inflowing channel, dries a to-be-dried material in the drying portion and then is discharged out of the outflowing channel; the drying portion comprises at least one drying chamber, at least two drying segments are arranged in each drying chamber, two or more drying segments are arranged sequentially in a spaced mode, and spaces between the adjacent drying segments form tempering segments; the drying medium from the inflowing channel flows through the drying segments; and the to-be-dried material is dried through one drying segment, then enters one tempering segment to be subjected to tempering, and then enters the next drying segment to be dried. According to the multistage heating and multistage tempering drying type airflow open-cycle heat pump drying system, through arrangement of the multiple heating drying segments and the multiple tempering segments, the drying production intensity of the drying portion is enhanced, and the heating energy efficiency ratios of heat pump units are greatly increased.

Description

technical field [0001] The invention relates to the technical field of drying heat pump design, in particular to an air flow open-circuit circulation drying system with multi-stage heating and multi-stage slow heat pump drying. Background technique [0002] The application of heat pumps to the medium-low temperature drying of wet materials such as wet grains has distinct characteristics of energy saving and environmental protection, and has attracted great attention in the field of thermal technology and all sectors of society. Quite a number of heat pump air-conditioning companies have tested the water for heat pump drying of grains, heat pump drying of wood, heat pump drying of agricultural products such as tobacco leaves, jujubes, wolfberries, grapes, black fungus, and Chinese herbal medicines, food products such as rice noodles, noodles, seafood, and preserved products The heat pump is dry and has achieved good results. [0003] However, the use of heat pumps for grain ...

AI Technical Summary

Problems solved by technology

[0018] The heat pump heating energy efficiency ratio is negatively correlated with the cycle temperature rise (condensing temperature - evaporation temperature) of the heat pump system; the lower the cycle temperature rise, the higher the heating energy efficiency ratio; the higher the cycle temperature rise, the lower the heating energy efficiency ratio , and every time the cycle temperature rise increases by 10°C, the heating energy efficiency ratio will decrease by about 20%; when the cycle temperature rise exceeds 60°C, the economy of the heat pump unit will be very poor

[0019] Second, high temperature drying reduces the quality of grain

[0023] However, as far as grain drying is concerned, the dry air with too high temperature will cause the surface and shallow layer of wet grain to lose water quickly and deeply, and the moisture gradient of internal humidity and external dryness will expand rapidly; Severe imbalance between grain and moisture content, resulting in cracks or even cracks in the grain, reducing the biological activity of the grain, and reducing the taste and quality of the grain

[0024] 3. Dust discharge from the drying device pollutes the air environment

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