液化天然气浸没燃烧式气化器数值模拟方法研究
发布时间：2018-08-06 10:30
【摘要】：为了考察在一定设计尺寸下液化天然气(LNG)浸没燃烧式气化系统的天然气出口温度能否达到生产要求,建立了对整个浸没燃烧式气化器(包含燃烧室、下气管和LNG换热器3部分)中一系列流动和传热的数值计算模型。在燃烧室中,采用灰气体加权和模型(WSGGM)计算烟气的吸收系数,利用DO模型求解辐射传递方程,并在考虑对流和辐射的混合传热作用下计算出火焰罩的壁面温度以及烟气、二次空气出口的平均温度;在LNG换热器中,对流体物性剧烈变化的管程进行分段处理并采用两相流体模型来模拟壳程中气液两相的流动和传热过程,在分别获得管壳两侧的平均传热系数后用以计算总的换热系数。所获得的管程和壳程对流换热系数和关联式与已有的文献值符合良好。壳程入口气体温度在500~700℃的范围内变动时,壳程出口气体温度与壳程水浴平均温度略微升高,同时壳程水浴湍动能降低,换热系数稍有减小。模拟获得的天然气出口温度可维持在15℃左右,能满足生产需要。
[Abstract]:In order to investigate whether the outlet temperature of liquefied natural gas (LNG) (LNG) submerged combustion gasification system can meet the production requirements under a certain design size, the whole submerged combustion gasifier (including combustion chamber) is established. The numerical model of a series of flow and heat transfer in the lower tube and LNG heat exchanger. In the combustion chamber, the ash gas weighted sum model (WSGGM) is used to calculate the absorption coefficient of flue gas, the do model is used to solve the radiation transfer equation, and the wall temperature and smoke of the flame cover are calculated by considering the heat transfer of convection and radiation. The average temperature of the secondary air outlet, in the LNG heat exchanger, the pipe side with dramatically changing fluid properties is treated in sections and the two-phase fluid model is used to simulate the gas-liquid two-phase flow and heat transfer process in the shell side. After obtaining the average heat transfer coefficient on both sides of the tube and shell, the total heat transfer coefficient is calculated. The convection heat transfer coefficient and correlation obtained in tube and shell are in good agreement with the available data. When the inlet gas temperature of the shell side changes in the range of 500 ~ 700 鈩，
本文编号：2167450
[Abstract]:In order to investigate whether the outlet temperature of liquefied natural gas (LNG) (LNG) submerged combustion gasification system can meet the production requirements under a certain design size, the whole submerged combustion gasifier (including combustion chamber) is established. The numerical model of a series of flow and heat transfer in the lower tube and LNG heat exchanger. In the combustion chamber, the ash gas weighted sum model (WSGGM) is used to calculate the absorption coefficient of flue gas, the do model is used to solve the radiation transfer equation, and the wall temperature and smoke of the flame cover are calculated by considering the heat transfer of convection and radiation. The average temperature of the secondary air outlet, in the LNG heat exchanger, the pipe side with dramatically changing fluid properties is treated in sections and the two-phase fluid model is used to simulate the gas-liquid two-phase flow and heat transfer process in the shell side. After obtaining the average heat transfer coefficient on both sides of the tube and shell, the total heat transfer coefficient is calculated. The convection heat transfer coefficient and correlation obtained in tube and shell are in good agreement with the available data. When the inlet gas temperature of the shell side changes in the range of 500 ~ 700 鈩，
本文编号：2167450
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