The Research And Development Design And Performance Of Total Heat Recovery Drying Unit

China is a big country of energy consumption,energy conservation and emission reduction pressure is huge,and drying is the largest energy consumption in the process of agricultural products processing,in the field of drying,research and development of low energy consumption drying equipment,reduce energy waste,reduce costs is an important direction of the current drying industry technology development.In this thesis,the advantages and disadvantages of the current drying methods are analyzed to overcome the impact of drying device on the nutrient composition and drying quality of materials,and a total heat recovery drying device is developed and designed.In this thesis,the design of the drying device includes a jacketed drying box and a jacketed drying box connected with the total heat recovery type air treatment device and the compressor unit and electronic control system integrated as a whole.The form of the device is a closed circulation system,refrigerant circulation and air circulation are through the air treatment device,dehumidification and temperature rise are completed in the air treatment device,no heat loss and heat transfer of the external environment,energy saving and efficient.In this thesis,the performance characteristics of the device are discussed by experiment and calculation.Under theoretical working conditions,through the comparison between the drying device and the ordinary heat pump drying device,it can be concluded that the unit energy consumption of the total heat recovery drying device can reach 1.2kg/(k W ·h)? 3kg/(k W ·h),performance coefficient of COP can reach 2.0 ? 5.0,which can meet the production needs.By changing the condensing temperature and evaporation temperature of the unit,the change of the performance coefficients of the drying unit was analyzed.It was found that the dehumidification and heating coefficient per unit energy consumption of the drying unit increased with the increase of evaporation temperature and decreased with the increase of condensation temperature when other parameters were unchanged.The data acquisition and control in the drying device mainly includes electrical control box and measuring instrument.The data of the sensor is collected by the PLC in the electronic control system.By installing the temperature and humidity sensor and needle probe and other electrical components in the drying oven,the following can be obtained: Material supply air temperature of the drying oven,return air temperature and air relative humidity,return air relative humidity were showed the same change trend,each part of the material in the drying oven drying temperature variation is consistent,considering the change of material moisture content analysis of the process of material drying respectively after preheating temperature,rapid drying,and finally slowly drying process,Finally reached the storage moisture content requirements.Finally,through the comparative experiment of rehydration of materials,it can be concluded that: the experimental dried materials have better color and lustre,no strong color change after soaking in water,and better rehydration is obviously different from other packaging products in the market.The design and production of the experimental drying device meet the use requirements,and realize the original design idea of avoiding the loss of material quality and nutrients caused by high temperature drying,which has a certain promotion value under the condition of controlling the cost.