摘要
导热系数是天然气水合物(以下简称水合物)重要的热物理学性质参数之一,但实验室制备的水合物样品中不可避免地存在孔隙,难以测得纯水合物导热系数。为此,基于热阻原理提出了一种新的水合物有效导热系数球形串并联模型,并结合已有的实验数据获得了纯甲烷水合物导热系数的半经验方程。同时,利用该模型计算了水合物样品的有效导热系数与孔隙度,分析了制备方法对样品品质的影响。研究结果表明:(1)压力介于4.0~9.5 MPa和温度介于263.15~279.15 K时,纯甲烷水合物的导热系数为0.755 7~0.771 2 W/(m·K);(2)较之于孔隙度,孔隙流体性质对测量值影响更大;(3)样品压实可以有效减小孔隙度,但无法达到零孔隙;(4)溶解气法制备的样品中残留表面活性剂,影响样品纯度;(5)预先压实冰粉法制备的样品平均孔隙度为18.73%±0.23%,优于一般的压实方法,且在纯度上优于溶解气法。结论认为,新的水合物有效导热系数球形串并联模型不仅可以更准确地计算水合物样品导热系数,而且还可以分析样品品质,进而为水合物资源开发和衍生技术的应用提供了可靠的基础数据。
Thermal conductivity is one of the important thermophysical parameters of natural gas hydrate(hereinafter referred to as hydrate),but the thermal conductivity of pure hydrate can be hardly measured because there are inevitably pores in the hydrate samples prepared in the laboratory.Based on the principle of thermal resistance,this paper proposes a new spherical series-parallel model for the effective thermal conductivity of hydrate.Based on the principle of thermal resistance,this paper proposes a new spherical series-parallel model for the effective thermal conductivity of hydrate.The semi-empirical equation of the thermal conductivity of pure methane hydrate was obtained according to the existing experimental data,while through this model,the effective thermal conductivity and porosity of hydrate samples are calculated and the influence of sample preparation method on sample quality is analyzed.And the following research results are obtained.First,the thermal conductivity of pure methane hydrate is in the range of 0.755 7-0.771 2 W/(m·K) under the pressure of 4.0-9.5 MPa and the temperature of 263.15-279.15 K.Second,compared with porosity,the properties of pore fluid have a greater influence on the measurement results.Third,sample compaction can effectively reduce porosity,but cannot realize zero porosity.Fourth,the residual surfactant in the sample prepared by the dissolved gas method impacts the purity of the sample.Fifth,the average porosity of samples prepared by the pre-compacted ice powder method is 18.73% ± 0.23%,which is better than that by the general compaction method.And from the perspective of purity,it is superior to the dissolved gas method.In conclusion,the proposed new spherical series-parallel model for the effective thermal conductivity of hydrate can not only calculate the thermal conductivity of hydrate samples more accurately,but also analyze the sample quality,which provides reliable basic data for the development of hydrate resources and the application of derivative technologies.
作者
孙始财
谷林霖
杨震东
李艳敏
SUN Shicai;GU Linlin;YANG Zhendong;LI Yanmin(Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation//College of Civil Engineering and Architecture,Shandong University of Science and Technology,Qingdao,Shandong 266590,China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2022年第10期131-138,共8页
Natural Gas Industry
基金
国家自然科学基金“水合物降压开采过程中裹挟气泡、砂粒的储层产水多相运移机理”(编号:52074165)
山东省自然科学基金项目“水合物聚散过程中导热性能动态特性”(编号:ZR2019ME116)、“基于地质分层的岩土热物性参数反演研究”(编号:ZR2020ME187)
青岛西海岸新区科技计划项目“LNG冷能—电厂烟气—水合物海水淡化一体化系统研究”(编号:2020-93)。
关键词
天然气水合物
有效导热系数
球形串并联模型
冰粉法
样品制备
样品品质
孔隙度
孔隙流体
Natural gas hydrate
Effective thermal conductivity
Spherical series-parallel model
Ice power method
Sample preparation
Sample quality
Porosity
Pore fluid
