Mad Money Jim Kramer Natural Gas Lecture

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Design principle

Working principle of a combined cycle power plant

In a thermal power station water is the working medium. High pressure steam requires strong, bulky components. High temperatures require expensive alloys made from nickel or cobalt, rather than inexpensive steel. These alloys limit practical steam temperatures to 655 °C while the lower temperature of a steam plant is fixed by the boiling point of water. With these limits, a steam plant has a fixed upper efficiency of 35 to 42%.

An open circuit gas turbine cycle has a compressor, a combustor and a turbine. For gas turbines the amount of metal that must withstand the high temperatures and pressures is small, and lower quantities of expensive materials can be used. In this type of cycle, the input temperature to the turbine (the firing temperature), is relatively high (900 to 1,400 °C). The output temperature of the flue gas is also high (450 to 650 °C). This is therefore high enough to provide heat for a second cycle which uses steam as the working fluid; (a Rankine cycle).

In a combined cycle power plant, the heat of the gas turbine's exhaust is used to generate steam by passing it through a heat recovery steam generator (HRSG) with a live steam temperature between 420 and 580 °C. The condenser of the Rankine cycle is usually cooled by water from a lake, river, sea or cooling towers. This temperature can be as low as 15 °C

In an automotive powerplant, an Otto, Diesel, Atkinson or similar engine would provide one part of the cycle and the waste heat would power a Rankine cycle steam or Stirling engine, which could either power ancillaries (such as the alternator) or be connected to the crankshaft by a turbo compounding system

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http://www.power-technology.com/projects/metcalf/

Natural Gas to Electric

How to create Naural Gas to Electriclty

Located in San Jose, the 602MW Metcalf Energy Center is now delivering power to northern California. Metcalf was the first large power generator in Silicon Valley, and is the cornerstone of energy supply and reliability for the region.

The natural gas plant was constructed by Bechtel Enterprises Inc. and is operated by Calpine Corporation. It was more than six years in the making, and cost close to $400m.

The Metcalf Energy Center lies at the southern base of Tulare Hill in northern Coyote Valley of South San Jose. The power plant itself occupies about 20 acres (half in Santa Clara County, half in the City of San Jose) of the project's 136 acres. Output can provide for the power needs of 600,000 area homes. Additional ambient air monitoring stations have also recently been installed.

COMBINED CYCLE TAKES 30% LESS FUEL
The power plant design has two combustion turbines generating up to 200MW, with steam injection power augmentation. There are two Heat Recovery Steam Generators (HRSGs) with duct burners, and a condensing steam turbine generator that can generate up to 235MW. The combined-cycle design allows Metcalf to consume up to 30% less natural gas than older power plants in the region.