A control method for precise temperature-controlled heat pump hot blast stove

Abstract

An accurate temperature control type heat pump hot blast stove control system and control method, wherein a temperature detection unit, a constant temperature adjustment unit and an air supply unit are arranged in the control system; Supply hot air that matches the set temperature into the air supply unit. A precise temperature-controlled heat pump hot blast stove control system and control method of the present invention, aiming at the particularity of the operation of the grain drying heat pump system, solve the problems of the heat pump hot blast stove in the external environment temperature change, the heat pump inlet air temperature change, and the fin frosting. In the case of various changing conditions such as defrosting, the innovative design and intelligent control logic of the system can realize the input selection of multi-stage different heating capacity and the precise control of the DC frequency conversion adjustment system, so as to realize the normal operation of the heat pump and ensure the heat pump The temperature of the outlet air is controlled within ±0.3 degrees of the difference from the set temperature to ensure the quality and quantity of drying materials.

Description

technical field [0001] The invention belongs to the field of grain drying, and in particular relates to a control method for a precise temperature control type heat pump hot blast stove. Background technique [0002] In recent years, my country's grain drying machinery and equipment industry has achieved rapid development, but on the whole it is still in a stage where the market is relatively chaotic, product technology is backward, corporate innovation capabilities are poor, research and development capabilities are weak, and one-time purchase costs are high. Laws and regulations, market level, technical level, etc., promote the sustainable, healthy and orderly development of the dryer industry. Existing grain drying technologies include natural air drying, sun drying, chemical fuel drying, electric heating, infrared, microwave drying, etc. Heat pump products do not have any combustion emissions, and the refrigerant is environmentally friendly refrigerant, which has zero pol...

AI Technical Summary

Problems solved by technology

However, the heat pump hot blast stoves on the market are just at the stage of promotion, and there are still many technologies that need innovation and breakthroughs

[0003] At present, there are still problems with the heat pump hot blast stoves used in the market: 1. When the system is running in winter, the outdoor ambient temperature is low, the evaporation temperature drops, and a thick layer of frost is easy to form on the surface of the evaporator, which leads to a decrease in the outlet air temperature of the unit , can not meet the drying temperature requirements

2. The products currently on the market are basically composed of multiple compressors. When the inlet air temperature of the heat pump hot blast stove changes, the compressor is automatically loaded or unloaded to meet the set air outlet temperature requirements, but each loading and unloading One compressor, so there will be a temperature fluctuation of about 8 degrees in the outlet air temperature, which will lead to uneven drying temperature of the grain, and poor drying effect in some periods of time

3. When the ambient temperature is low, because the unit needs to defrost, the defrosting air temperature will also decrease, which will affect the stability of the air temperature

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