Establishing a mathematical model for automotive air conditioning systems

The heat exchanger model library utilizes the model library. The user enters the parameters (including the heat exchanger's application code, the heat exchanger's type, the heat exchanger's structural parameters, the material parameters, the evaporator The inlet air volume or the oncoming wind speed of the condenser, the dry and wet bulb temperature of the inlet air, the type of the refrigerant, the flow rate of the refrigerant, and the temperature and pressure value of the refrigerant at the inlet), and the heat exchanger is calculated at a given operating condition The performance of the heat exchanger (including the heat exchange capacity of the condenser, the cooling capacity of the evaporator, the pressure drop at the air side and the inside of the tube, and the temperature and pressure value of the refrigerant at the outlet); this model library can also calculate the heat exchanger structure separately. Changes in parameters, changes in wind speed or air volume at the inlet air of the heat exchanger, changes in the performance of the heat exchanger when the temperature of the inlet air of the heat exchanger changes, and are reflected in the form of curves. The model library can be used to calculate the relationship between opening degree and flow rate of various types of H-type expansion valve and external-balanced expansion valve, providing a reference for the user to choose the expansion valve rationally.

The tank model library calls this model library to calculate the volume and flow resistance of various types of tanks. Reasonable selection of liquid storage tanks for users to provide reference. The model database of the air-conditioning system is based on the thermal load value calculated from the heat load model library, the allowable installation space location of the vehicle, and the existing components and other factors to reasonably match the automotive air-conditioning refrigeration system, and then establish the mathematical model of the automotive air-conditioning system. The following functions can be achieved by using this model library: simulation simulation of bench simulations; calculation of various operating modes can be performed. The calculation of the known refrigerant charge or the required charge capacity can be performed; the calculation of various connection methods can be performed; for a given automotive air-conditioning refrigeration system, changing the compressor speed, changing the condenser inlet air temperature or facing The performance of the automotive air-conditioning refrigeration system (eg, cooling capacity, power consumption, coefficient of performance, evaporator outlet air supply temperature, compression ratio, compressor suction temperature, etc.) under conditions such as wind speed, variable evaporator inlet air temperature, or air volume. The effects of pressure, exhaust temperature, and pressure are represented in a curve, which provides a reference for predicting the matching and operating conditions of the air conditioning system.