Research On Thermal And Moisture Environment Simulation And Ventilation Optimization Design Of High Voltage Distribution Room

The stable operation of electrical equipment in high-voltage distribution room is the premise of safe and reliable transmission and distribution of power system.In recent years,more and more 12 k V outdoor power distribution equipment are put into operation,however,due to the structural characteristics such as sealing and compact structure and improper control of hot and humid environment,in the actual operation process,excessive temperature rise and poor indoor hot and humid environment lead to frequent electrical equipment overheating and damp phenomenon;The main content of this paper is to intuitively obtain the temperature rise of the electrical equipment in the actual operation and the heat and humidity level of the environment of the high-voltage distribution room,analyze the relevant influencing factors,so as to carry out effective control.(1)The thermal characteristics of typical electrical equipment switchgear in high-voltage distribution room are analyzed,the structural characteristics of the switchgear are described.combined with the heat transfer theory,the heat balance equation in the cabinet was constructed,then,the three-dimensional simulation model of KYN28A-12 k V intermediate metal-armored shifting switch cabinet was built,the mesh was divided and the boundary conditions were applied,the temperature field was solved by the finite element method to obtain the temperature field distribution of the internal current-carrying loop of the switch cabinet,the results of temperature rise test show that the calculation error is within 4.2%.The analysis shows that due to the existence of contact resistance,the temperature distribution of the downloadable circuit in the normal operation of the switchgear is not uniform,and the overall temperature difference reaches 44.6℃.When there is short-term overload or the ambient temperature is higher than 35℃,the maximum temperature rise of the switchgear will be higher than the allowable value;When the wall convection coefficient changes below 40 W/(m~2·K),it has a great influence on the temperature field of the switch cabinet,but the influence is not obvious when the wall convection coefficient changes above 40 W/(m~2·K).(2)Simplified three-dimensional simulation model was established for the typical high-pressure distribution room,combined with computational fluid dynamics,the heat and humidity distribution and flow field in the high-pressure distribution room environment were simulated,it was found that when the internal switchgear was a stable heat source,the indoor ambient temperature was higher than 35℃,which could not meet the engineering requirements;Then,the distribution characteristics of the heat and humidity environment in the high-pressure distribution room under the ventilation mode were studied,and the influence rules of the location of the tuyere,ventilation volume and environmental temperature and humidity parameters on the indoor temperature and humidity distribution were obtained,as well as the distribution characteristics of indoor heat and humidity coupling.(3)Designed the 6 kinds of high voltage transformer room hot wet environment control ventilation arrangement plan,through the simulation analysis,summarized under different ventilation arrangement scheme,indoor temperature field and flow field distribution features,and the six schemes under room temperature and flow field distribution,get reasonable through the air volume,flow displacement ventilation mode has the highest ratio of air to coverage,the oblique symmetrical arrangement of air supply outlet and exhaust outlet has the best control effect on indoor hot and humid environment.