Control System Of Bulk Curing Barn Baking Based On Internal Circulation Dehumidification

Bulk curing barn was an important carrier for tobacco leaf baking,and baking control was an important way to obtain high quality dry tobacco leaves.Although the domestic tobacco leaf baking technology had been greatly improved at this stage,there were still many problems.The used of coal,biomass,etc.as the main fuel caused waste of resources,harmful gases to pollute the environment,and also leaded to poor controllability of the baking process;The dehumidification method by air venting caused the heat in the smoking chamber and the substances precipitated during the baking process of the tobacco to be directly discharged,which not only reduced the quality of the smoking and the appearance of the tobacco,but also increased the energy consumption.The existing barn control system and baking technology were mainly developed for the coal-fired bulk curing barn.Therefore,the control object was single,the control precision was low,the baking process was simple,and the control requirements of the advanced bulk curing barn were not applicable.In view of the above problems,this paper proposed a method based on internal circulation dehumidification of tobacco leaf baking,an internal circulation dehumidification modification scheme of existing bulk curing barn,and developed a control system based on internal circulation dehumidification baking.The main contents were as follows:(1)By analyzing and studying the main technical parameters,baking method and baking technology of the existing bulk curing barn,the tobacco leaf baking method based on internal circulation dehumidification was proposed;combined with the working principle of the baking method and the traditional tobacco leaf baking process,An "eight-stage" baking technology suitable for internal circulation dehumidification was proposed.(2)According to the structural characteristics of the existing bulk curing barn and the demand for heat generation and dehumidification in the baking process of tobacco leaves,designed the internal circulation dehumidification transformation technical scheme of the existing bulk curing barn,and on this basis,developed for the transformation the inner circulation heating and dehumidifying device of the baking room realized the connection and installation of the modified baking room and the heating and dehumidifying device by the principle of optimal energy utilization.(3)Based on the research and development of the internal circulation dehumidification bulk curing barn renovation and heating and dehumidifying device,design the hardware circuit,fuzzy decoupling controller and embedded software program of the baking control system;the hardware circuit was based on STM32 MCU,It mainly included: temperature acquisition circuit,relay and its drive circuit,display interface circuit,etc.;based on the internal circulation dehumidification baking method and the control requirements of the "eight-stage" baking technology,the fuzzy decoupling control based on multi-parameter was designed.The embedded software program mainly included: a main program module,abaking control module,a heating dehumidification control module,a control algorithm execution program,and the like.(4)According to the internal circulation dehumidification reform scheme of the bulk curing barn,the existing coal-fired barn shall be modified accordingly,the heating and dehumidifying device shall be installed,the baking control system shall be connected,and then the equipment debugging,no-load experiment,tobacco leaf baking test shall be carried out.The test results were analyzed,and the energy-saving effect of using the internal circulation dehumidification bulk curing barn was remarkable.The internal material degradation,transformation and synthesis of tobacco leaves were sufficient,and had high chemical quality.