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地下变电站通风空调系统的研究及节能优化

Study and Energy-saving Optimization of the Ventilationand Air Conditioning System in Underground Transformer Substation

【作者】 杨小平

【导师】 刘刚;

【作者基本信息】 东华大学 , 供热、供燃气、通风及空调工程, 2011, 硕士

【摘要】 城市供电设施是城市基础设施的重要组成部分,随着城市化进程的不断加速,建设全地下变电站是大势所趋。静安(世博)地下变电站是国内首座500kV全地下变电站,站内设备种类多、散热量大,设备安全运行保证要求高,然而目前与此类大型地下变电站通风空调系统设计有关的标准不健全,也缺乏相应的实践经验和参考工程。因此以世博变电站为对象,通过研究其通风空调系统,找到最优化的设计参数,既符合节能的目标,也可以为类似后续工程提供技术支持。本文分地下和地上两个部分来研究变电站的通风空调系统。地下部分首先以发热量最大的220kV主变压器室为研究对象,采用CFD软件根据所测得实际通风数据,对变压器室内的流场和温度场进行数值模拟,湍流模拟采用Realizable k-ε模型,温度项采用Boussinesq假设。模拟结果与实测温度数据得到了很好的吻合,由此验证了本文数值模拟的可靠性。在此基础上通过改变通风方式、送风口高度、风口有效面积等要素,得到节能优化的通风方案。并以此模拟方法研究了其它设备间(电抗器、站用变室、接地变室)的最佳空调送风参数。地上部分为大空间模拟,主要研究排风的扩散路径及其对进风温度的影响,并对室外环境进行简化处理,模拟无外界因素干扰和有室外风(风速、风向)干扰下进风温度的状况,通过尝试各种方法(增大风井距离、排风口高度、地面种植植被等)来降低进风温度受影响的程度。地下部分模拟结果:变压器室内通风管分居在机器对角两侧的送风方式、送风口中心高度在1.5-1.7m之间、送风口有效风速在4.56-5.91m/s之间即风口有效面积在1.4-1.08m2范围最有利于新风的扩散和降温。35kV的电抗器室最佳送风温度为30℃、通风量为21523m3/h,其他设备间送风参数见表4-4。地上部分模拟结果:排风在无外界因素干扰下的扩散不影响进风温度;室外风速在0-5m/s之间时,进风温度受影响的程度有所不同,1m/s时进风温升最大,不同风向下(东南风、南风、西南风)排风的扩散状况不同但对进风温度影响程度差别不大;提高排风口高度、种植树木等方式不能改变排风扩散路径,而增大风井间距、降低地面热力状况的方式可以有效降低进风温度受影响的程度,因此在进排风井所在区域种植草皮并且种植有一定间隔的树木(高大、叶面积密度大)与草坪相结合遮挡太阳辐射,尽可能的降低地面温度是解决问题的有效途径。

【Abstract】 Power supply facilities is an important part of the infrastructure of cities. With the accelerated urbanization process, it is a general trend to construct underground substation. Jing An (EXPO) underground substation is the first 500kV whole underground substation in china, with many species equipments, a great capacity of heat emission, and a high requirement of guarantee for safe running of the equipments. However, now the standards related to the design of ventilation and air conditioning system for such large underground substation are not perfect, the corresponding practice experience and the reference project also lacks. Therefore, by setting the EXPO substation as the object of the study, through investigating on its ventilation and air conditioning system, find the optimized design parameters, not only be in accord with energy conservation target, but also can provide technical support for similar follow-up project.This article is divided into two parts of underground and overground to study ventilation and air conditioning system. For the underground part, first take the 220kV main transformer room for example, according to the actual measured ventilation data, simulate the flow field and temperature field of the transformer room, adopt Realizable k-εturbulence model and Boussinesq assumption. The simulation results tallies with the actual temperature data, which validated the reliability of numerical simulation. On this basis, by changing the ventilation mode, air vent height, air vent effective area etc, we can get an energy saving optimized scheme. The simulation method was used for other devices (such as reactor, station transformer room, grounding transformer room) to find the best supply parameters. Overground part adopt large space simulate, mainly research on the diffusion path of the air exhaust and the influence to the temperature of inlet air, simplified the outdoor environment, simulated the temperature of inlet air on condition that no external factors and have disturbance from outdoor wind (wind speed, wind direction), and tried various methods (increase air shaft distance, air outlets height, ground vegetation etc) to reduce the inlet air temperature affected degree.The simulation results of underground part:the most favorable mode for fresh air diffusion and cooling includes several aspects:separate the ventilating pipe in diagonal on either side of the machine, the height of air supply outlet is between 1.5-1.7m, the effective wind speed is between 4.56-5.91m/s. The optimal supply air temperature of reactor room 35kV is 30℃, the ventilation capacity is 21523m3, air supply parameters of other devices room see table 4-4.The simulation results of overground part:diffusion of air outlet without disturb from external factors will not affect the inlet air temperature, when the outdoor wind speed is b etween 0-5m/s, the air inlet temperature is affected differently, when the speed is lm/s the temperature rise maximized, the diffusion of air outlet is differed with the different wi nddirection (southeast, south, southwest), but this have little difference on the inlet air tem perature affected degree. By improving the air outlet height, planting trees, etc which cann ot change the outlet air diffusion path, but the way of increase air shaft distance, reduce ground thermal condition can effectively reduce the inlet air temperature affected degree. T herefore planted grass in air inlet area and trees have a certain space (tall, leaf area big d ensity), combined with the lawn can block out the solar radiation, reduce ground temperat ure as low as possible is an effective way to solve the problem.

  • 【网络出版投稿人】 东华大学
  • 【网络出版年期】2011年 07期
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