The Black Point Power Station gas supply project

Castle Peak Power Company Limited, Hong Kong (CAPCO).A joint venture between ExxonMobil Energy Ltd. and CLP Power Hong Kong Ltd.

Black Point Power Station (BPPS) was the firstnatural gas-fired power generation facilityin Hong Kong. Its eight single-shaft unitswere put into service in phases from 1996 to 2006,and with 2,500MW of installed capacity, it is oneof the largest gas-fired combined cycle stations inthe world.

The facilities at Black Point were originallydesigned to burn gas from one dedicated source,the Yacheng 13-1 gas field in the South ChinaSea. That supply is now rapidly depleting, and theStation must be prepared for a transition to newsources of gas.

In 2008, the Hong Kong and Central governmentssigned a Memorandum of Understanding toprovide Hong Kong with natural gas from differentnew sources.

The first source to go live is the Second West-East Natural Gas Pipeline. Spanning nearly 9,000kilometres, it is the world’s longest natural gaspipeline passing through 14 different provinces andregions of China. The natural gas from Turkmenistanin Central Asia is then brought all the way throughChina to the Pearl River Delta, reaching Shenzhen,and then be sent along a branch line to BPPS in Hong Kong.

The multiple new gas supplies will have differentqualities from the current source and, similar toissues faced in other parts of the world, the gasqualities may vary more widely from what theinstalled equipment is designed for use. In orderto make the transition, the Station required majorenhancements to enable it to manage a diverse portfolio of future gas sources.

The Project’s objective is to upgrade the Stationwith new gas receiving and gas conditioningsystems. The enhancements give the operatorsflexibility to utilize multiple gas sources concurrentlyeven when each source may have a substantiallydifferent and variable gas quality.

A new Gas Receiving Station (GRS) has been builtto provide a second inlet for gas at BPPS. It adjuststhe temperature and pressure of the secondary gasstream to match the primary gas inlet.

This facility has a large turndown ratio, whichmaximizes the operator’s ability to select the desiredproportions of gas to be received from each inlet.Gas from the new GRS is then conveyed via asecond, parallel distribution system to the eightpower generation units.

Each power generation unit is being retrofittedwith a dynamic Fuel Quality Management System(FQMS). The FQMS reads incoming gas qualitydata and uses a heater to correct the combustionproperties of the gas in real time just upstream ofthe gas turbine.

In conjunction with new turbine hardware andcontrol system upgrades, this modification enableseach generation unit at the Station to regulateand moderate the dynamic changes in its gasspecification that otherwise might push it outsidenormal operating range.

Finally, two of the Station’s eight generation unitsare being upgraded with facilities that will allowoperators to blend gas from both the old and newGRS and send the mixed stream to the gas turbine.Along with the FQMS to manage the combustionproperties, this modification allows the Station evenfiner control over gas source utilization.

When work is completed in 2013, the Gas SupplyProject will have enabled BPPS to operate with abroad portfolio of concurrent gas supplies, eachof which may have different and variable qualityspecifications.

It will be successfully putting into operation aunique combination of technologies that allowsthe Station to source a wide range of gases andpresents a new benchmark in operational flexibilityfor managing multiple gas sources at a gas-firedpower station.