基于FLACS的氢气检测器布置优化

采用某石化装置1∶1模型,以位于框架平台上的氢气分液罐泄漏为例,运用事故后果模拟软件FLACS构建计算流体力学模型并将氢气检测器设置为模型中的检测点,通过氢气泄漏及扩散过程数值模拟获得各检测点的氢气体积分数及响应时间,据此对氢气检测器的布置进行优化。主要研究成果有:1)提出氢气检测器探测效率的评价标准;2)明确工程中氢气检测器相对于潜在释放源的最优水平和竖向位置;3)给出花纹钢板和格栅板2种不同上层平台形式下氢气检测器的布置方案。

Ways to achieve the goal of hydrogen detection optimization on the basis of FLACS

The present paper is to pursue the optimization of the hydrogen detection based on the consequence modeling software known as FLACS. In the practice of our simulation,it is assumed that the flange seal of the hydrogen knock-out drum is located at the platform,which is supposed to fail with the hydrogen jets out of the small hole. In such a situation,it is supposed to create 4 simulated scenarios to denote the same jet direction and different wind directions. To gain the hydrogen concentration data,we have set up the monitoring points at the different horizontal and vertical positions. And,finally,we have managed to optimize the pre-defined concentration rates and adjust their locations accordingly through monitoring the time to reach the monitoring points. The main conclusive points of this paper should include:( 1) On the basis of the first level alarming data as prescribed in GB 50493-2009,the time to arrive at the first level alarming data can be defined as the standard point for the detection efficiency evaluation;( 2) This paper tries to use the newly proposed standard for evaluating the performance of the monitoring points whereas the results indicate that the jet direction plays a decisive role in the location of the hydrogen detectors. Nevertheless,it is not possible to know the jet direction in advance in engineering practice. Therefore,the present paper has brought about the best horizontal and vertical distances to the potential release source on account both of the detection efficiency and the proper cost.( 3) It is also possible both to locate the platform of the hydrogen handling equipments at above platform models of steel plates and the grates of the hydrogen handling equipments.In given paper,we have compared the dispersion of hydrogen under the different platform models. And,in general,for the sake of safety conservation,the grating platform is preferred to be put above the hydrogen handling equipment. As to the hydrogen detectors located under the grating platform,the alarming data should be set lower for better detection efficiency. Thus,the conclusions made above can be expected to benefit engineers to arrange the hydrogen detectors in the petrochemical plants,and help achieve the goal not only to meet the demands of the current specification,but also make it more reasonable and efficient.