1、PDF外文：http:/ 中文3265字1 毕业 设计 （ 论文 ）外文 文献 翻译 （本科学生用） 题 目： 为了未来的发展，液化天然气工艺处理过程中应该注意的问题 学 生 姓 名： 学号 ： 学 部 （系） :
2、城市建设工程学部 专 业 年 级 :级建筑环境与设备工程班 指 导 教 师： 年月日 2 LNG PROCESS SELECTION CONSIDERATIONS FOR FUTURE DEVELOPMENTS John B. Stone Senior LNG Consultant Dawn L. Rymer Senior Engineering Specialist Eric D. Nelson Machinery and Pr
3、ocessing Technology Supervisor Robert D. Denton Senior Process Consultant ExxonMobil Upstream Research Company Houston, Texas, USA ABSTRACT The history of the LNG industry has been dominated by the constant search for economies of scale culminating in the current Qatar mega-trains undergoing final c
4、onstruction, commissioning,start-up and operations. While these large trains are appropriate for the large Qatar gas resources, future, smaller resource developments will necessitate different process selection strategies. The actual LNG process is only one of many factors affecting the optimal choi
5、ce. The choice of equipment, especially cryogenic heat exchangers and refrigerant compressors, can overwhelm small differences in process efficiencies. ExxonMobil has been developing a dual mixed refrigerant (DMR) process that has the potential of offering the scalability and expandability required
6、to meet the needs of new project developments, while also maximizing the number of equipment vendors to allow broader competition and keep costs under control. The process will also have the flexibility to accommodate a wide range of feed compositions, rates, and product sales requirements. BA
7、CKGROUND The startup of the 7.8 million tonnes per year (MTPA) trains in Qatar mark the most recent pinnacle in the search for economies of scale in the LNG industry. However, theapplication of these very large trains for general LNG applications is very limited. To produce this amount of LNG requir
8、es 42 MSCMD (1500 MSCFD) of feed gas. What is often overlooked in the discussion of large LNG trains is that a resource of about 370 GCM (13 TCF) is needed to support the operation of one such train over a 25-year life. This is nearly as large as the Arun field in Indonesia 425 GCM (15 TCF), which w
9、as the backbone of the LNG plant development in that region. For new LNG developments that are often built with a minimum of two identical trains, a truly world-class resource class of 750 GCM (26 TCF) would be required. Even for resources capable of supporting such large trains, very large gas trea
10、ting and preparation trains with a minimum of parallel 3 equipment are also needed to ensure that economies of scale are not lost in the non-LNG facilities. Given the limited supply of gas resources capable of supporting these large trains, future projects will need to find ways to maintain so
11、me cost advantages at smaller capacities. One way to do this is to improve the project execution by selecting a process that gives the maximum flexibility for utilizing compressors, heat exchangers, and drivers with multiple competing vendors. Another desirable feature is using refrigerant as a util
12、ity to allow for facilitated expansion if there is a possibility that several resources can be staged for expansion trains. PROCESS COMPARISON LNG process selection has often been highly influenced by the specific power consumption, i.e., refrigerant compression power divided by the train capacity.
13、This is certainly an important parameter, since refrigerant compressors are the largest single cost and energy consumption components in an LNG train. Conventional wisdom would be that lower specific power consumption would result in lower refrigerant compression costs and additional LNG production from a fixed feed gas rate. In actuality it is a more complicated picture. Figure 1 plots the specific power consumptions for a variety of liquefaction processes against the number of cycles employed based on consistent conditions.
