Research On The Constant Temperature Characteristics And Control System Of Scalability Refrigerator

With the continuous improvement of modern scientific and technological level and living standard,the market demand of agricultural products is becoming more and more diversified.At present,with the rapid development of modern logistics cold chain and the extensive application of refrigeration technology make the refrigeration equipment more and more attention.In this paper,research on the scalability refrigerator,is to solve the problem of fruits and vegetables storage in the old residential buildings of the northern area in winter.There are some shortcomings,such as unsuitable for the storage environment,uncontrollable for the temperature,unfeasible and ventilated for the space,serious string taste,dry consumption.In this paper,the constant temperature characteristics and control system of the scalability refrigerator are studied.Firstly,the thermodynamic calculation of the refrigeration system is carried out.According to the use environment and conditions,the cold load of the refrigerator to be calculated.Refer to its refrigeration conditions and find the relevant thermodynamic parameters,as a basis for the thermal calculation of the refrigeration system,so as to determine the refrigeration components and select the compressor model.Meanwhile the condenser and evaporator are selected and their structural parameters are determined.Secondly,research the constant temperature characteristic of the refrigerator.Using Gambit to build the geometrical model of the refrigerator and divide the mesh,and using Fluent to carry out the numerical analysis,with hypothetical model,define the boundary condition,Fluent solver calculation.The temperature field simulation is carried out on four constant temperature characteristics of the position of the inlet and outlet,the size of the inlet and outlet,the velocity of the inlet,and the thickness of the insulation layer.By comparing the simulation results under different parameters,the best temperature field and flow field distribution were obtained,and the optimum conditions for storage of fruits and vegetables were determined.Finally,design the structure and automatic constant temperature control system of the refrigerator with the above two aspects of research.The overall structure and components of refrigerator were properly designed according to the results of constant temperature characteristics of refrigerator.Meanwhile,establish three-dimensional model.Automatic temperature control system use ARM microcontroller technology.Design the main circuit of the master control system module.The system used incremental PID control to achieve automatic constant temperature control with the main program designed independently.The display interface was designed at the same time.