开放式厨房燃气泄漏爆炸定量风险评价

Quantitative risk assessment of gas leakage and explosion in open kitchens

各地燃气公司面临越来越多给开放式厨房通气的诉求,但依据国内现行标准规范,开放式厨房不能通气。根据典型开放式厨房的布局尺寸与居民户内燃气系统参数,分别建立了开放式厨房、有隔断厨房布局下的燃气泄漏扩散爆炸数值模型。基于相似理论,研制了开放式厨房燃气泄漏扩散爆炸试验装置并开展了系列试验,验证了数值模型的准确性。提出了以室内爆炸危险区域占比表征事故发生概率、以室内加权平均超压表征事故后果的室内燃气泄漏爆炸定量风险评价方法,并将该方法运用于量化对比某典型户型在开放式厨房和有隔断厨房2种布局方式下的燃气泄漏爆炸风险差异。结果表明:1)开放式厨房布局由于无实体墙阻碍,燃气泄漏扩散范围相对更大,导致其事故发生概率为有隔断厨房布局的2.4倍;但开放式厨房布局具有更低的室内阻塞比,爆炸过程中的湍流强化效应相对较小,使得其事故后果影响也相对较小,仅为有隔断厨房布局的0.57倍;总体而言,开放式厨房布局方式的燃气泄漏爆炸风险更高,是有隔断厨房布局的1.37倍;2)可通过提高户内燃气管道及用气设备本质安全水平、设置燃气泄漏报警联锁停气通风等方式,有效消减和控制开放式厨房用气风险。

Urban gas companies in China are facing more and more gas supply applications for open kitchens each year.However,open kitchens cannot make use of gas for cooking based on the current domestic standards.According to the layout of a typical open kitchen and the actual parameters of indoor gas supply system,numerical models for gas leakage and explosion under the open kitchen layout and the partitioned kitchen layout are established,respectively.The experimental setup for modeling gas leakage and explosion in open kitchens was designed based on the similarity theory.A series of experiments were carried out to verify the accuracy of numerical models.A novel quantitative risk assessment method applicable for indoor gas explosions is presented.The proportion of hazardous area generated by an indoor explosion is used to represent the accident probability,while the weighted average indoor overpressure is adopted to represent the accident consequence.The quantitative risks for indoor gas explosion between the open kitchen layout and the partitioned kitchen layout are evaluated,respectively.The results show that the accident probability of gas explosion for the open kitchen layout is 2.4 times that for the partitioned kitchen layout.It is due to the fact that indoor gas diffusion has no obstruction from the open kitchen walls,resulting in a much larger gas diffusion region.Meanwhile,the accident consequence in the open kitchen layout is only 0.57 times that for the partitioned kitchen layout since there is a less blockage ratio for the open kitchen layout.Consequently,the total risk of gas leakage in the open kitchen layout is 1.37 times that in the partitioned kitchen layout.Finally,effective measures for risk reduction in terms of gas explosion in open kitchens are proposed,including improving the intrinsic safety level of indoor gas facilities and interlocking gas supply and ventilation in case of gas leakage.