沼气调峰用LNG混空装置的设计与测试

Design and test of LNG air mixing device for biogas peak shaving

针对沼气产气量不稳定的问题,提出了采用LNG气化掺混空气作为沼气调峰气源的解决方案,设计并加工了一种LNG引射空气混合器,模拟生产实际对引射混合器的运行特性进行了实验研究。结果表明在引射器出口压力一定时,混气比(空气∶天然气)随着进口压力的增加而显著提升;进口压力一定时,混气比随着出口压力的增加而逐渐减小;考虑进出口压力对混气比的共同作用时,提高进口压力,混气比随出口压力升高而降低的趋势减缓;提高出口压力,混气比随进口压力升高而上升的趋势加剧。为获得与沼气发酵罐相同的出口压力,引射器进口压力应为0.25 MPa。

Using the gasified LNG mixing air as source gas of biogas peak shaving was proposed as a solution that the biogas output is unstable.In order to obtain the mixed gas,a LNG air ejector mixer was designed and processed,and the ejector mixer was investigated experimentally in the simulation of actual production for obtaining the operating characteristics.The results indicate that the air and gas mixing ratio markedly rises with the increase of inlet pressure when the outlet pressure is constant,but the result is opposite when the inlet pressure is constant.Under the condition of interacting by both the inlet and outlet pressure,the air and gas mixing ratio drops with the increase of outlet pressure when the inlet pressure increases,and the tendency of dropping is step-down.But the tendency is completely opposite when the outlet pressure increases.In order to match the outlet pressure of biogas fermentation tank,the ejector mixer should keep the inlet pressure of 0.25 MPa.