Calculation And Analysis Of CFD For Heat Flow Field In Locomotive Power Room

Power room is where diesel engine generator set which is the power source of diesel locomotive lies,usually located in the middle of locomotive,and the interior is equipped with diesel engine,main generator,engine intake filter,exciter,etc.The total heat emitted by diesel engine is usually only 35%—45% can be transformed into effective power,while a large part of the remaining heat is discharged directly from the diesel engine.which will not only result in the loss of diesel engine,but also make the ambient temperature of power room too high.Excessive temperature will bring adverse effect to the inspection and maintenance of workers,moreover,it will lead to the failure rate of relevant equipments increased.Through rationally design the structure of power room,it can effectively improve the ventilation and cooling conditions,decrease the ambient temperature of power room,reduce the power consumption of cooling fan,improve the reliability of electrical motor and other equipment.In this paper,the ventilation system of power room is taken as the research object,and the CFD method is used to simulate the ventilation and heat dissipation performance under different work conditions.Firstly,three-dimensional modeling software Creo is used to model the power room of locomotive;Then the heat flow field of power room is simulated based on the CFD software FLUENT,using SIMPLE algorithm,choosing standard k-ε model;Finally,the detailed flow information at different speeds is obtained.The results show that the interior average temperature of initial scheme is higher than 60℃ at different speeds,which does not meet design requirement.The structure of power room is improved and simulated again by analyzing the distribution of parameters,such as temperature,pressure,velocity,turbulence kinetic energy and turbulent dissipation rate in detail,and studying the interior air flow characteristics.After a series of adjustments and optimizations,the optimal structure scheme satisfying the ventilation and heat dissipation requirement is obtained finally.Analyzing the air flow condition before and after the structural improvement,it can be observed that because the optimized scheme add fans to the ventilation openings of power room,speed up the air flow at the vent,significantly enhanced the turbulence performance of fluid,thus the heat transfer effect of ventilation is strengthened,the interior temperature of power room is reduced.The average temperature in each condition can be maintained at about 60℃,which meet the cooling requirement of power room.