Rainer Kurz Matt Lubomirsky

索拉透平公司， 加利福尼亚州 圣地亚哥 92123

1 Pipeline Sizing Considerations管线选型考虑

Kurz and Ohanian［1］evaluated different options for pipe diameters，pressure ratings and station spacing for a long distance pipeline.A 3 220 km(2 000 mile)onshore buried gas transmission pipeline for transporting natural gas with a gravity of 0.6 was assumed(Figure 1).

Kurz R 和Ohanian S［1］评估了对于长距离管线，管道直径、压力等级与站场间距的不同选择。本文假定一条3 220 km(2 000 mile)的陆上埋地天然气输送管线，输送气体密度为0.6(图1)。

Assuming that pipes will be available in2”diameter increments from pipe mills，the nearest even increments of the above-mentioned theoretical diameters were selected(24”，28”，and 34”for 152 bar，103 bar and 69 bar(1 bar=0.1 MPa)pressures respectively)and analyzed by varying the number of stations along the pipeline.The result of this refinement is shown in Figure 1，where present value is plotted against number of stations for each pressure level. The minima for each are shown in the chart with present value，total horsepower，and number of stations.In this study，the 69 bar pipeline has the lowest present value，thus would be the most cost effective solution.

Figure 1:Optimum number of stations and optimum maximum operating pressure(MAOP)for the 3 220 km(2 000mile)，560 000Nm3/h sample pipeline.The lowest cost configurations for each MAOP solution are marked(from［1］).图1 一条长3 220 km(2 000 mile)、输量为560 000 Nm3/h

假定来自制管厂的钢管直径以2”的间隔增加，选择24”、28”与34”及其分别对应压力152、103 与69 bar(1 bar=0.1 MPa)的3 条管线，对沿线不同的布站数量进行分析。这样细化研究的结果见图1，图1 中绘制了不同压力等级下布站数量对应的净现值。每种情况的折合净现值如图1 所示，图上反映了投资、总装机功率、压气站数量。该案列说明，69 bar 管线的净现值最低，因此是最经济的解决方案。

In actual practice，for commonality reasons，identical size units will be installed in the stations.In order to have identical power at each station，the station spacing will be adjusted(dependent on the geography)since the stations at the beginning of the line will consume more power than the stations at the end of the line due to the power required for fuel compression. Identical power at each location also depends on site elevation and design ambient temperature，which would define the site available power from a certain engine.

在实际应用中，为了保持机组的统一，同一站内应安装相同的机组。为了保持各站有相同的功率需求，需要根据地形调整站间距，由于沿途各站存在自耗气，下游的输气总量小于首站及管道上游各站，因此管线首站比管线末站消耗更多的压缩功。为保持相同功率而选择的站址也受海拔与设计环境温度影响，因为这些因素决定燃机的实际现场出力。

One of the key findings is，that the optimum is relatively flat in all cases.This meansin particular，that certain considerations may favor larger station spacing，with higher station pressure ratios，and higher MAOP in situations where pipelines are routed through largely unpopulated areas.

其中一个重要发现是，最优方案对于其它方案来说其优势并不特别突出。这就意味着若管线穿过人烟稀少的地区则可以考虑增大站间距，提高站的压比与MAOP(最大允许操作压力)。

2 Typical Application典例应用

For a case study we consider an international long distance pipeline. The total length of the line is about 7 000 km.The pipeline consists of two 42”parallel lines which turn into single a 48”line at the crossing of an international border. The pipeline design throughput is 30 billion Nm3per year and maximum operating pressure of this pipeline is 9.8 MPa.There are 10 compressor stations planned in one area，and over 20 stations in the receiving country.After first gas，it takes 5 years to build up to full capacity.

在案例研究中我们评估了一条跨国长输管线，线路总长度为7 000 km。管线由2 根42”并行管线组成，在跨越国境边界合并为1 根48”管线。管线设计输送能力300 ×108m3/a，最大运行压力9.8 MPa。……