Control method of drying system and drying system

Abstract

The invention relates to a control method of a drying system and the drying system, and belongs to the technical field of drying control. The drying system comprises a heat pump, an auxiliary electricheating module and a moisture exhaust draught fan. The control method includes the steps of determining the entered drying control stage; obtaining environment parameters of drying space corresponding to the drying control stage; and carrying out linkage control on control objects at the drying control stage according to the environment parameters and variation gradients of the drying space. Thecontrol method of the drying system and the drying system are conductive to promoting the stability of environment parameter changes of the drying space, thus contributing to improving the drying quality of products.

Description

technical field [0001] The application belongs to the technical field of drying control, and in particular relates to a drying system control method and a drying system. Background technique [0002] The heat pump operation and auxiliary electric heating operation control of the traditional dehumidification heat pump dryer are mainly reflected in the following two aspects: [0003] 1. Heat pump heating and temperature rise control stage in drying room: heat pump operation and auxiliary electric heating are turned on synchronously, and they are turned off synchronously after stopping at the temperature point to maximize the temperature rise rate of the drying room. Among them, the dryer is generally equipped with 5 to 10 times as standard. Group auxiliary electric heating adopts the control mode of synchronous operation or synchronous cut-out. [0004] Control Disadvantages: [0005] 1. This control method maximizes the temperature rise rate of the drying room, but the temp...

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Problems solved by technology

[0005] 1. This control method maximizes the temperature rise rate of the drying room, but the temperature rise rate of the drying room cannot be controlled, which may easily lead to failure to meet the process temperature rise and drying curve of the dried crops (for example, if the temperature rise rate is too fast, the dried crops will be browned. Dust hanging due to rapid temperature drying), reducing drying quality

[0006] 2. In this control mode, 5 to 10 groups of auxiliary electric heating are controlled at the same time on and off at the same time (for example, each group of auxiliary electric heating is 2kW, and the heat load fluctuation of the drying room is nearly 10 to 20kW during the start and stop of auxiliary electric heating) , it is very easy to cause drastic fluctuations in the temperature of the drying room at the cut-in and cut-out points of the auxiliary electric heating, increase the inhomogeneity of the temperature field inside the drying room, affect the process accuracy of the temperature control of the drying room, and even reduce the drying quality

[0009] The centrifugal fan has a large dehumidification capacity, simple periodic start-stop control, no sensible heat recovery device, resulting in a large heat loss in the drying room, and the heat pump heating capacity at full load still cannot meet the dehumidification demand, and cannot take into account the temperature and humidity of the drying room need

Excessive moisture removal results in drastic temperature fluctuations in the drying room, which affects the evaporation of moisture in the dried crops. Insufficient moisture removal results in excessive humidity in the drying room, which can easily cause high-temperature, high-humidity corruption of the dried crops.

[0010] Summary: In the traditional dehumidification heat pump dryer, the operation of the heat pump and the auxiliary electric heating are controlled at the same time or at the same time, and the auxiliary electric heating is controlled by synchronous operation or synchronous cut-out, and the centrifugal fan is periodically started and stopped. Control, the above-mentioned control method makes the environmental parameter control of the drying room have the disadvantage of fluctuating violently, which has an adverse effect on the drying quality of the product

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