| With the continuous progress of urbanization in China,the subway in the major cities have been rapid popular,the number of subway passengers is also increasing.The thermal environment of the subway car is also getting more and more attention.Most of the subway cars run underground,and the number of passengers changes dramatically,with ordinary buildings and long-distance trains in the air conditioning control strategy is very different.China is currently in the subway car air conditioning system control there is no clear standard,all over the subway car air conditioning system control methods are also different.In order to meet the requirements of passenger’s thermal comfort and the efficient operation of subway car air-conditioning,it is very important to study the control strategy of subway car air-conditioning.This paper first analyzes the different characteristics of the thermal environment of ordinary residential,office buildings and long distance train air conditioning system and subway car air conditioning system.Through the law of conservation of energy and the characteristics of the subway compartment to build subway car air conditioning system and subway car control mathematical model.The current subway and more temperature as the car thermal environment control objectives there are many shortcomings,prone to overheating and overheating.This paper proposes to use PMV as the control target of subway car thermal environment.Considering the influence of temperature,humidity,wind speed,average radiation temperature,metabolic rate,clothing resistance and other factors on the thermal comfort of the human body,it is more accurate to reflect the thermal comfort of the passengers.To improve the thermal comfort of the passengers and the energy saving of the air-conditioning Very important meaning.According to the outdoor meteorological parameters to determine the human body clothing thermal resistance,according to the number of passengers to calculate the body’s metabolic rate,according to the indoor temperature calculation of the average radiation temperature,through simulation and norms to determine the use of cars for the car,PMV calculated wind speed and humidity.After determining the above parameters based on the PMV calculation formula,the preparation of the relevant procedures to calculate the subway car PMV.Then the fuzzy PID control strategy is proposed.The fuzzy PID controller controls the compressor frequency of the air conditioning unit to change the cooling capacity of the air conditioning unit,thus changing the thermal environment of the car.The traditional subway air conditioning to start and stop the way to control the temperature inside the compartment,the temperature fluctuations.The use of fuzzy PID control strategy real-time adjustment of air conditioning compressor frequency,so that subway cars PMV value has been in the appropriate interval.SIMULINK is used to simulate the fuzzy PID control system of subway vehicle air conditioning,and the simulation results are compared with the traditional PID control.Simulation and comparison show that fuzzy PID control can be better applied to subway vehicle air conditioning system.Finally,according to the control strategy of the subway air conditioning system fuzzy PID controller production,and vehicle air conditioning ground test and controller simulation experiments. |
