Design Of Type B Subway Air Conditioning And Ventilation System And Simulation And Verification Of Passenger Room Flow Field

The development of urbanization promotes the continuous growth of the domestic economy,while enjoying urban civilization,traffic congestion,commuting noise and exhaust pollution have become obstacles to urban development.The subway has many advantages such as high efficiency,low carbon,and environmental protection,which can properly solve the problems caused by traffic.Therefore,cities at all levels are vigorously developing subway transportation.The air supply comfort of the air conditioning system is an important indicator to measure the performance of the subway.Human comfort requirements and the temperature field near the human body are particularly important.In order to avoid excessive differences in wind speed and temperature and affect passengers’ comfort on the subway,the uniformity of temperature and wind speed must be controlled within a reasonable range.The main research contents of this article are as follows:1.According to the design experience of many subway projects in the past,through the parameters and operating environment of the subway vehicles,and from the cooling capacity and air supply of the air conditioning unit,the internal baffle of the air duct system,the main air cavity and the static pressure cavity,waste discharge The system’s air exhaust volume,the air outlet design of the interior grille of the passenger room ceiling,the installation position of various system components in the air conditioning system on the subway vehicle,etc.were analyzed,and the air conditioning and ventilation system of a domestic subway was designed.2.Using computational fluid dynamics technology,created a three-dimensional calculation model of the air duct system in the subway car and the passenger compartment,simulated the turbulent flow field in the passenger compartment,and obtained the sitting head and standing head in the passenger compartment under AW0 and AW2 conditions The distribution of the wind speed field and temperature field at the location has been verified by simulation: when the ambient temperature reaches +33℃,it can ensure that the temperature in the passenger room is not higher than +28℃ under AW2.And the airflow velocity is higher than 0.07m/s,avoiding the "static zone",The average breeze velocity in the passenger compartment 1.7m away from the floor is in the range of 0.3-0.5m/s.3.The cooling capacity and air supply volume of the air conditioning unit were tested in the enthalpy difference method laboratory.And tested the temperature,humidity and wind speed in the AW0 state on the real subway vehicle.When the air conditioning unit system is running,according to the test points specified in the standard,the air velocity is tested to be higher than 0.07m/s,which avoids the "static area".The average breeze speed at 1.7m fromthe floor in the passenger compartment is within the range of 0.4-0.5m/s,the result of the test is similar to the result of the simulation calculation.The results of this article have a guiding significance for the design of subway vehicles.Therefore,the air-conditioning and ventilation system platform suitable for Type B subway vehicles can be promoted.