天然气水合物间壁热采实验研究

Experimental Study on Exploitation of Natural Gas Hydrateby by Wall Heat Transfer

利用温度震荡法合成高质量水合物,开展不同间壁换热温度的定容分解开采天然气水合物实验,研究热采过程中产气量和天然气水合物体系导入热量的变化规律,提出纯能量效率概念,同时结合传热学理论,实现了纯能量效率的计算。结果表明:天然气水合物间壁换热开采的纯能量效率介于10~40,间壁温度30℃时的纯能量效率最高,间壁温度增大,整个间壁热采过程的纯能量效率和单位时间的纯能量效率逐渐降低。在天然气水合物间壁热采时,应尽量控制热量的沿程热损失和外逸热损失,使用较低的间壁温度,能够取得较好的水合物开采效益。

High-quality natural gas hydrate was synthesized by temperature oscillation method,and then constant volume decomposition experiments of natural gas hydrate at different wall heat transfer temperatures were carried out to study the relationship between gas production and heat input of natural gas hydrate system during thermal recovery.The concept of pure energy efficiency is put forward,and the calculation of pure energy efficiency is realized according to heat transfer theory.The result shows that the pure energy efficiency of natural gas hydrate wall heat transfer mining is 10~40,and the highest pure energy efficiency is obtained when the wall temperature is 30℃.Then,the pure energy efficiency and the pure energy efficiency of unit time in the process of wall heat transfer recovery gradually decrease with the increase of wall temperature.In the thermal recovery of natural gas hydrate,the heat loss along the course and exogenous heat loss should be controlled as far as possible.Using lower wall temperature can achieve better recovery benefit of natural gas hydrate.