Precise temperature control type heat pump hot blast heater control system and control method

Abstract

Disclosed is a precise temperature control type heat pump hot blast heater control system and control method. A temperature detection unit, a constant temperature adjusting unit and an air supply unitare arranged in the control system. According to the control system, hot air matched with the set temperature is supplied in from the air supply unit through cooperation of the temperature detectionunit and the constant temperature adjusting unit. According to the precise temperature control type heat pump hot blast heater control system and control method, aiming at the particularity of operation of a grain drying heat pump system, when a heat pump hot blast heater is in various change working conditions such as change of the external environment temperature, change of heat pump inlet air temperature, fin frosting and defrosting, through innovative design and intelligent control logic of the control system, input selection of multilevel different heating capacities and precise control direct current frequency conversion adjusting system are achieved, the effect that difference value of the outlet air temperature of the heat pump and the set temperature is controlled and maintained to be within the range of + / -0.3 DEG C is ensured when the heat pump operates normally, and quality and the drying amount of dried material are ensured.

Description

technical field [0001] The invention belongs to the field of grain drying, and in particular relates to a control system and a control method for a precise temperature-controlled 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 as a whole, it is still in a stage of relatively chaotic market, backward product technology, poor innovation ability, weak R&D ability, and high one-time purchase cost. Regulations, market level, technical level, etc., promote the sustainable, healthy and orderly development of the dryer industry. The existing grain drying technologies include natural air drying, sun drying, burning chemical fuel drying, electric heating, infrared, microwave drying, etc. The heat pump products do not have any combustion emissions, and the refrigerants are environmentally friendly refrigerants, which have zero pollution to the ozone layer. Better env...

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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