混氢天然气物性规律及管道水合物生成模拟分析

氢能是一种绿色低碳的二次能源，在天然气管道中掺入氢气进行大规模运输是当前研究的热门领域。但氢气与天然气混合后因其物性参数的改变，使管道产生堵塞、氢脆、泄漏、聚积、燃烧和爆炸等问题。基于此，利用Aspen HYSYS软件，选取代表性数据，运用理论研究、数据模拟和数据分析等方法，针对不同混氢比下天然气与氢气混合后的物性变化规律和管道水合物生成情况进行模拟分析。结果表明：随着混氢比增大，混合气体温度先降低再升高，在混氢比为36%时达到最低温度；混合后气体质量密度和比热容比与混氢比呈负相关；质量焓、质量熵、质量基准热值、Z因子、热导率、运动黏度均与混氢比成正相关；随着混氢比增大，水合物生成温度降低，压力升高。可见在天然气管道中适当混入少量氢气可抑制水合物的生成；混氢天然气物性参数变化规律为探究适合不同条件下的最优混氢比、保证管道输送及使用的安全性提供了数据基础。

Physical property law of mixed hydrogen natural gas and simulation analysis of pipeline hydrate formation

Based on carbon peak, carbon neutral background, green low-carbon secondary energy-hydrogen energy, has become the ultimate form of energy use may be mixed in natural gas pipelines for large-scale transport of hydrogen is a hot area of current research. However, due to the change of physical parameters of hydrogen and natural gas, the pipeline has problems such as blockage, hydrogen embrittlement, leakage, accumulation, combustion and explosion. Based on this essential problem, Aspen HYSYS software is used to select representative data, and theoretical research, data simulation and data analysis are used to simulate and analyze the physical property change law and pipeline hydrate formation after natural gas and hydrogen mixing under different mixing ratios. The results show that with the increase of mixed hydrogen ratio, the temperature of mixed gas decreases first and then increases, and the lowest temperature is reached at 36% mixed hydrogen ratio. The gas mass density and Cp/Cv after mixing are negatively correlated with the hydrogen mixing ratio. Mass enthalpy, mass entropy, mass reference calorific value, Z factor, thermal conductivity and kinematic viscosity are positively correlated with hydrogen mixing ratio. With the increase of hydrogen mixing ratio, the hydrate formation temperature decreases and the pressure increases. It can be seen that proper mixing of a small amount of hydrogen in natural gas pipelines can inhibit the formation of hydrates; the variation law of physical parameters of mixed hydrogen natural gas provides a data basis for exploring the optimal mixed hydrogen ratio under different conditions and ensuring the safety of pipeline transportation and use.