沼气制油橇装装置的燃爆风险分析与优化设计

基于经济和技术可行性方面的考虑,沼气制油通常都采用小型模块式橇装化装置,但目前对于该类橇装装置的燃爆风险与优化设计方面的研究极少。为此,以某沼气制油橇装化装置为研究对象,采用HYSYS软件模拟沼气制油生产中可燃气体的动态泄漏过程,计算在过程控制系统干预下的动态气体泄漏速率,进而结合计算流体力学软件(FLACS)预测不同橇装模块(以下简称橇块)的安全间距、不同保护隔板排布方式下的爆炸强度和影响范围。研究结果表明:①增大橇块间的安全间距可以明显降低气云爆炸火焰传播造成的湍流扰动,其中爆炸远端压力监测板的爆炸超压最大值(p_(max))在安全间距为3 m时为721.1 Pa,在安全间距为9 m时则降低为83.68 Pa;②其他变量一致时,点火源位于橇块内部产生的p_(max)值大于两橇块之间;③在橇块两侧加保护隔板会加剧可燃气体爆炸后的超压,在装置实际工况下50 mm大孔动态泄漏导致的p_(max)值为5.784 kPa。结论认为,在橇块单侧增加保护隔板,可以在起到泄压作用的同时降低爆炸伤害(该排布方式不会产生过高爆炸超压);橇块间安全间距设置为6 m或者更大,可以在降低爆炸伤害的前提下尽可能节省装置的空间占位。

Risk analysis of gas explosion on a biogas-to-liquid fuel skid-mounted device and an optimal design

Based on the consideration of economic and technological feasibility, a small-scale skid-mounted device is the main scheme of a biogas-to-liquid fuel plant, neither explosion risk analysis nor optimal design of which, however, have yet been fully investigated at home and abroad. Therefore, in a case study, we adopted the HYSYS to simulated and calculate the rate of dynamic explosive gas leakage in the biogas-to-liquid fuel production process. Then, combined the computational fluid dynamics software FLACS, we predicted safety distances of different skid-mounted modules, explosion strength and influence scope under different layouts of protective baffles. The following results were concluded. (1) To expand such safety distance of modules will obviously reduce turbulence disturbance resulted from flame propagation in gas cloud explosion. When the safety distance was 3 m, the maximum explosion overpressure (pmax) was 721.1 Pa presented at the pressure monitoring board at the distal end of explosion, and was significantly down to 83.68 Pa when the safety distance became 9 m. (2) When other variables are consistent, the pmax value produced by the ignition source inside a module is greater than that between the two modules. (3) Protective partition on both sides of a module will aggravate the overpressure of combustible gas after explosion. The pmax value was up to 5.784 Pa resulted from the macroporous leakage with the diameter of 50 mm under the actual working condition of the device. On this basis, we suggested that protective partition should be installed at one side of a module so as to reduce explosion damage while relieving pressure. This arrangement will not produce excessive explosive overpressure. The safety distance between modules should be 6 m or more than that so as to save the space occupancy of the device as much as possible on the premise of reducing explosion damage.