Research On Heating System And Thermal Comfort Of Metro Vehicle Based On Carbon Fiber

With the rapid development of rail transit,passengers have put forward higher requirements for the comfort of the ride environment.Especially in the winter in the northern region,how to provide the citizens with a warm and comfortable ride environment has become an urgent problem to be solved.In the north of China,subway vehicles generally adopt air conditioning preheating and electric heat pipe auxiliary heating,which has low thermal efficiency and high energy consumption.Due to the electric heater are normally installed at the bottom of the seat,heat dissipation in a way that is mainly rely on natural convection is complete,tend to form local heat concentration,caused by uneven distribution of temperature in carriage,destroy the passengers ride comfort.In order to solve the problems existing in the traditional heating system of subway vehicles,this paper applies the carbon fiber hot line to the heating system of rail vehicles for the first time.Of cars in the amount of heating during the winter has carried on the detailed calculation,and then based on the carbon fiber heating characteristics of the electric heater and the structure of the car,the car ventilation mode and the installation position of heater is analyzed.Then,the annual average of initial investment cost and initial investment cost of carbon fiber electric heating system are calculated respectively.Finally,the temperature field and velocity field of the car are simulated,and the thermal comfort of the car based on carbon fiber electric heating system is analyzed.Through calculation analysis and numerical simulation,it is concluded that the total power of "car A" and "car B and car C" satisfying the requirements of heating is 14.4kW and 15.6kW respectively.The ventilation way on the lower side is more in line with the requirements of car heating.The longitudinal installation of carbon fiber electric heater is more conducive to the improvement of thermal comfort.The initial investment cost of carbon fiber electric heating system is slightly higher than that of traditional electric heating system,but the annual average investment cost is much lower than that of the latter,and the investment payback period only takes 56 days.Under steady state,the temperature field in the carriage is evenly distributed and the thermal comfort is good.Open the door,the temperature field was greatly affected by the near the door,but the car temperature stability of the upper middle area remain above 19 ℃;After the door is closed,the temperature in the carriage returns to the comfortable level,which meets the heating requirements of the subway car.