| With the continuous advancement of industrialization,China has built many large substations in windy and sandy area.When the wind-sand is large,the dust will cause great harm to the building(construction)and electrical equipment body and operation of the substation,which will seriously affect the safety and stability of the whole system.When the equipment of distribution room of substation is running,it will emit a lot of heat,if not be eliminated in time,the electrical equipment is prone to cause over-temperature faults,which is detrimental to its service life and safety and reliability.Therefore,how to effectively solve the problem of outdoor wind-sand control and indoor ventilation and heat dissipation for the distribution room of substation in windy and sandy area has become a hot topic in recent years.In this paper,the field measurement and simulation calculation of a 35 kV SVC distribution room in Lanzhou New Area were carried out in the early stage.The comparison and analysis of the measured average and the numerical simulation results at the same measuring points show that the coincidence of the two results is good,which verifies the reliability of the numerical model and simulation method used in this paper.Then,based on the actual project of a substation in the windy and sandy area,the 35 kV SVC distribution room with the largest heat dissipation in the substation is taken as the research object,and the main factors affecting the indoor and outdoor flow field of the distribution room in the windy and sandy area are analyzed.The CFD method is used to simulate the two major aspects: The first is to simulate the distribution of the flow field in the original ventilation program,the optimized program,the different supply wind speed,the different supply wind temperature,and the different inlet angle of the louvers,studying the distribution law and exploring the best parameters of that contribute to ventilation and cooling of the distribution room;the second is to simulate the outdoor flow field under the two-phase flow of the wind-sand,studying the influence of different wind speeds and different particle sizes on the outdoor flow field and sand trajectory,and the following conclusions are obtained:(1)Under the premise of ensuring that the air inlet parameters unchanged,considering the optimization schemes,increasing the number of air inlet louvers from 6 to 9,that is,increasing the air inlet area by 50%,can effectively improve the problem of poor ventilation and cooling in distribution room.(2)When the other air inlet parameters are constant,the ventilation cooling effect of the distribution room is more obvious with the increase of the air supply speed;when the air inlet temperature is 303 K and the wind speed reaches 0.5m/s,the residual heat generated by the electrical equipment can be eliminated;When the wind speed is 0.5m/s and the temperaturedoes not exceed 306 K,the indoor high temperature can be effectively reduced;Under the premise of preventing sand and dust,when the angle of the inlet louver is 60°,the ventilation and cooling effect of the distribution room is the best.(3)The outdoor wind-sand flows through the distribution room,and the positive pressure is concentrated on the windward side of the distribution room,the negative pressure is mainly distributed on both sides and the leeward side.As the outdoor wind speed increases,the negative pressure area of the leeward side of the distribution room becomes significantly larger,and the eddy current becomes stronger.The "local strong wind" appears on oblique rear of the top and sides of the distribution room,and its maximum speed is 1.26 times of the incoming wind speed.(4)The distribution of sand trajectories of the same particle size is similar at each wind speed;the distribution of sand trajectories of different particle sizes is different under the same wind speed;the higher the wind speed,the smaller the particle size,the greater the distance of sand from the wind. |
