Optimization research on natural gas hydrate hole-bottom freezing sampler based on the heat pipe enhanced heat transfer

Abstract:

Aiming at the key technical bottleneck of low cold source utilization rate in natural gas hydrate hole-bottom freezing sampler， an optimization scheme using heat pipes to enhance heat transfer was proposed. A sampling device test bench was built to conduct indoor experiments on gas hydrate core freezing， and study the effect of heat pipes optimized heat transfer between the cold storage mechanism and the freezing mechanism. Combined with the numerical simulation of heat transfer， the role of heat pipes in the sampler was further analyzed to explore the effects of different initial temperatures of cold sources and core lengths on the freezing effect of the freezing mechanism under the working condition of marine hydrate coring. The research results show that optimizing the structure with the heat pipe makes the temperature distribution of the core more uniform， increases the cold source utilization rate by 31.59%， and the core freezing rate by 42.21%. The use of heat pipes to strengthen heat transfer enhances the freezing effect of the natural gas hydrate hole-bottom freezing sampler， which is of positive significance for promoting the engineering application of the hole-bottom freezing sampler and breaking the monopoly of foreign countries on hydrate sampling technology.