Simulation calculation and performance analysis KLD29 roof unit air conditioning unit was selected, and the system simulation model was used to calculate and analyze the influence of air temperature change inside and outside the vehicle on the running performance of air conditioning unit. The air conditioning unit belongs to a return air system, the air volume of the condenser is 10000m3/h, the air volume of the evaporator is 4500m3/h, and the fresh air volume is 1500m3/h. During the operation of the air conditioning unit, the air temperature of the external environment changes, and the change of the ambient air temperature will affect the operating performance of the air conditioning unit. At the same time, the air conditioning load in the car changes due to the flow of passengers and other factors, resulting in changes in the air temperature inside the car, which will also affect the operating performance of the air conditioning unit. When the air temperature in the car changes from 22 °C to 30 °C, and the air temperature outside the car changes from 32 °C to 40 °C, the main performance parameters of the train air conditioning unit change. The evaporating temperature changes with the temperature of the air inside and outside the car. 1) Evaporation temperature The temperature of the air inside the car rises and the evaporating temperature increases. The temperature of the outside air increases and the evaporating temperature increases. When the air temperature in the vehicle changes from 22 °C to 30 °C under the same air temperature outside the vehicle, the evaporation temperature increases by nearly 1 °C; when the air temperature outside the vehicle changes from 32 °C to 40 °C in the same vehicle air temperature The evaporation temperature increased by 3 °C. The condensation temperature varies with the temperature of the air inside and outside the vehicle. 2) Condensation temperature The temperature of the air inside the vehicle increases, and the condensation temperature rises. The temperature of the outside air increases and the condensation temperature increases. In the same outside air temperature, when the air temperature in the car changes from 22 °C to 30 °C, the condensation temperature rises slightly, and the rise value is less than 1 °C; in the same vehicle air temperature, the outside air temperature is from 32 When the temperature changes from °C to 40 °C, the condensation temperature rises to 8 °C. The power consumption of the compressor varies with the temperature of the air inside and outside the vehicle. 3) The power consumption of the compressor increases the air temperature inside the vehicle, and the power consumption of the compressor increases. The air temperature outside the vehicle increases, and the power consumption of the compressor increases. In the same outside air temperature, when the air temperature in the car changes from 22 °C to 30 °C, the power consumption of the compressor increases slightly, increasing by about 1%; in the same air temperature of the car, the air temperature outside the car is from 32 °C. When the temperature changes to ~40 °C, the power consumption of the compressor increases sharply, and the increase rate reaches 13%. The cooling capacity varies with the temperature of the air inside and outside the vehicle. 4) Cooling capacity The air temperature inside the vehicle increases, and the cooling capacity increases. The temperature of the outside air increases and the cooling capacity decreases. At the same outside air temperature, when the air temperature in the vehicle changes from 22 °C to 30 °C, the cooling capacity increases by about 3%; when the air temperature outside the vehicle changes from 32 °C to 40 °C in the same vehicle air temperature, The cooling capacity is reduced by about 3%. The COP changes with the air temperature inside and outside the vehicle. 5) The COP air temperature rises and the COP rises; the outside air temperature rises and the COP decreases. At the same outside air temperature, when the air temperature in the car changes from 22 °C to 30 °C, the COP increases slightly, increasing by about 2%; in the same indoor air temperature, the outside air temperature is from 32 °C to 40 °C. When it changed, COP dropped sharply, dropping by about 14%. The air outlet temperature of the air conditioning unit changes with the air temperature inside and outside the vehicle. 6) The air temperature of the air conditioning unit increases. The air temperature of the air conditioner unit increases, and the air temperature of the air conditioning unit increases. The air temperature outside the vehicle increases, and the air temperature of the air conditioning unit increases. When the air temperature in the vehicle changes from 22 °C to 30 °C under the same air temperature outside the vehicle, the air outlet temperature of the air conditioning unit increases by about 3 °C; in the same air temperature of the vehicle, the air temperature outside the vehicle ranges from 32 °C to 40 °C. When changing, the air outlet temperature of the air conditioning unit rises by about 2 °C. Conclusion 1) The air temperature in the car increases, the evaporating temperature increases, the condensing temperature increases, the compressor power increases, the cooling capacity increases, and the COP increases, but the magnitude of the change is not large; although the air temperature in the car increases, the cooling capacity Increasing, since the inlet air temperature of the evaporator also rises at the same time, the air outlet temperature of the air conditioning unit is increased. 2) The temperature of the air outside the vehicle rises, the evaporation temperature increases, the condensing temperature increases, the compressor power increases, the cooling capacity decreases, the COP decreases, and the air outlet temperature of the air conditioning unit rises, and the magnitude of the change is relatively large. Roll Forming Machine,W Beam Guardrail Forming Machine,Guard Rail Forming Machine Taigong Roll Forming Machinery Co., Ltd. , http://www.hbformingmachine.com
The compressor model compressor uses the efficiency method to establish a model, which simplifies the complex refrigerant flow and heat transfer process inside the compressor to the functional form <5>:) expressed by the lumped parameter method. (121mTPfW=(13) W represents the compressor power (W), and subscripts 1 and 2 represent the compressor inlet and outlet states, respectively.