Abstract:

In order to explore the changing law and influencing factors of the filtering performance of natural gas filter elements under high pressure conditions, four types of filter elements were selected as the research objects, and field tests and laboratory performance tests were carried out. The evaluation was carried out in turn according to the technical standards, including the field test for about 410 d, the laboratory test before and after the field test, and the performance test on filter layers. It was found that after the field test, the pressure drop in filter cartridges increased by about 20%, and the rise rate of pressure drop increased even more under the same experiment condition of gas-solid filtration, while the relative difference of the filtration efficiency and quality factor decreased between the four types of filter cartridges. The filter layers were compressed by 7%—31% under the high-pressure condition. As particles were embedded or deposited at the filter media, the permeability of each filter layer generally decreased while the tensile strength of the material increased. Besides, some methods were shown to benefit the stable and reliable operation of the filter cartridge under high pressure conditions, including the selection of fiber material with uniform pore size distribution, composite material with cascade design of filtration accuracy, pleating of filtration layers and inlet side skeleton with pre-separation and diversion functions. The research provides a guidance for the development and optimization of separation cartridges suitable for high-pressure natural gas transportation.

Key words: natural gas, filtration, porous media, pressure drop, pore size

摘要：

为探究高压工况下天然气滤芯的过滤性能变化规律及影响因素，选取了四种规格的滤芯为研究对象，开展了现场实验和实验室性能测试。发现在现场运行410 d后，四种滤芯的压差平均增长约20%，在相同气固过滤实验条件下压差增长速率更大，而四种滤芯的过滤效率和品质因子的差异相对缩小。高压工况下过滤材料压缩了7%~31%，大量颗粒嵌入过滤材料或沉积在表面，各过滤层的透气度普遍下降，而抗拉强度均有所上升。结果表明，选用孔径分布均匀的纤维材料、过滤精度梯级设计的复合材料，对过滤层打褶以及采用导流式骨架，均有助于滤芯在高压运行工况下长周期稳定可靠运行。

关键词: 天然气, 过滤, 多孔介质, 压差, 孔径