无消防水池的变电站火灾工况数值模拟研究

当前,建于市区的变电站为了节约用地,其消防系统通常不建设消防水池,消防用水直接从市政管网取水,该消防模式下的取水安全及管网响应情况值得关注。论文以某城市中心城区为例,采用EPANET 2.0构建了供水管网模型,针对供水高峰、流量转输和事故爆管3种不利供水条件,开展了无消防水池变电站的消防系统5种不同火灾工况的水力计算与数值模拟研究。结果表明,发生火灾时,由于需水量增加,市政管网自由水头值整体降低,但仅临近变电站的部分节点水头显著降低,不足28 mH_2O。从市政供水管网的两路干管取水灭火,可提高变电站消防供水的可靠性。变电站在管网中的位置不同,其在消防取水时对市政管网的影响差异明显,位于管网末梢的变电站消防取水时,其对供水管网的影响作用显著高于距供水水源较近的变电站。研究成果可为无消防水池变电站的水消防系统的设计和运行提供理论与技术支撑。

Numerical simulation of substation fire conditions without fire pool

At present, to save land, the water for the fire-fighting system of substations built in urban areas is usually taken from the municipal pipe networks directly, instead of building fire pools. More attention should be paid to the safety of water intake and the response of pipe network. Taking the central urban area of city A as an example, a water supply network model was built using EPANET 2.0 in this paper. For three unfavorable water supply conditions, namely peak water supply, flow transfer and accidental pipe burst, hydraulic calculation and numerical simulation of five different fire conditions of fire protection system in substation without fire pool are carried out. The results show that the free head value of municipal pipe network decreases as a whole due to the increase of water demand in case of fire, but only the water head of some nodes near the substation decreases significantly, less than 28 mH2O. The reliability of the fire water supply in substation could be improved when the water is taken from two main pipes of the municipal water supply network. The influence of substation on municipal pipe network is evident when the substation is located in different positions. When the substation located at the end of the pipe network takes water for fire protection, its influence on the water supply network is significantly higher than that of the substation close to the water supply source. The research results can provide theoretical support for the design and operation of water fire protection system in substation without fire pool.