Closed-cycle gas turbine

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Closed-cycle gas turbine schematic

C compressor and T turbine assembly
w high-temperature heat exchanger
w low-temperature heat exchanger
~ mechanical load, e.g. electric generator Schem turb gaz3 en-simple.svg
Closed-cycle gas turbine schematic

C compressor and T turbine assembly
w high-temperature heat exchanger
ʍ low-temperature heat exchanger
~ mechanical load, e.g. electric generator

A closed-cycle gas turbine is a turbine that uses a gas (e.g. air, nitrogen, helium, argon, [1] [2] etc.) for the working fluid as part of a closed thermodynamic system. Heat is supplied from an external source. [3] Such recirculating turbines follow the Brayton cycle. [4] [5]

Contents

Background

The initial patent for a closed-cycle gas turbine (CCGT) was issued in 1935 and they were first used commercially in 1939. [3] Seven CCGT units were built in Switzerland and Germany by 1978. [2] Historically, CCGTs found most use as external combustion engines "with fuels such as bituminous coal, brown coal and blast furnace gas" but were superseded by open cycle gas turbines using cleaner-burning fuels (e.g. "gas or light oil"), especially in highly efficient combined cycle systems. [3] Air-based CCGT systems have demonstrated very high availability and reliability. [6] The most notable helium-based system thus far was Oberhausen 2, a 50 megawatt cogeneration plant that operated from 1975 to 1987 in Germany. [7] Compared to Europe where the technology was originally developed, CCGT is not well known in the US. [8]

Nuclear power

Gas-cooled reactors powering helium-based closed-cycle gas turbines were suggested in 1945. [8] The experimental ML-1 nuclear reactor in the early-1960s used a nitrogen-based CCGT operating at 0.9 MPa. [9] The cancelled pebble bed modular reactor was intended to be coupled with a helium CCGT. [10] Future nuclear (Generation IV reactors) may employ CCGT for power generation, [3] e.g. Flibe Energy intends to produce a liquid fluoride thorium reactor coupled with a CCGT. [11]

Development

Closed-cycle gas turbines hold promise for use with future high temperature solar power [3] and fusion power [2] generation.

They have also been proposed as a technology for use in long-term space exploration. [12]

Supercritical carbon dioxide closed-cycle gas turbines are under development; "The main advantage of the supercritical CO2 cycle is comparable efficiency with the helium Brayton cycle at significantly lower temperature" (550 °C vs. 850 °C), but with the disadvantage of higher pressure (20 MPa vs. 8 MPa). [13] Sandia National Laboratories has a goal of developing a 10 MWe supercritical CO2 demonstration CCGT by 2019. [14]

See also

Related Research Articles

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<span class="mw-page-title-main">Pressurized water reactor</span> Type of nuclear reactor

A pressurized water reactor (PWR) is a type of light-water nuclear reactor. PWRs constitute the large majority of the world's nuclear power plants. In a PWR, the primary coolant (water) is pumped under high pressure to the reactor core where it is heated by the energy released by the fission of atoms. The heated, high pressure water then flows to a steam generator, where it transfers its thermal energy to lower pressure water of a secondary system where steam is generated. The steam then drives turbines, which spin an electric generator. In contrast to a boiling water reactor (BWR), pressure in the primary coolant loop prevents the water from boiling within the reactor. All light-water reactors use ordinary water as both coolant and neutron moderator. Most use anywhere from two to four vertically mounted steam generators; VVER reactors use horizontal steam generators.

<span class="mw-page-title-main">Pebble-bed reactor</span> Type of very-high-temperature reactor

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<span class="mw-page-title-main">Combined cycle power plant</span> Assembly of heat engines that work in tandem from the same source of heat

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<span class="mw-page-title-main">Gas-cooled fast reactor</span> Type of nuclear reactor cooled by a gas

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<span class="mw-page-title-main">Liquid fluoride thorium reactor</span> Type of nuclear reactor that uses molten material as fuel

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References

  1. Nitrogen or Air Versus Helium for Nuclear Closed Cycle Gas Turbines | Atomic Insights
  2. 1 2 3 "AN ASSESSMENT OF THE BRAYTON CYCLE FOR HIGH PERFORMANCE POWER PLANTS" (PDF). Archived from the original (PDF) on 29 June 2010. Retrieved 10 June 2012.
  3. 1 2 3 4 5 Frutschi, Hans Ulrich (2005). Closed-Cycle Gas Turbines. ASME Press. ISBN   0-7918-0226-4. Archived from the original on 21 December 2011. Retrieved 7 December 2011.Note: front matter (including preface and introduction; PDF link) is open access.
  4. Thermodynamics and Propulsion: Brayton Cycle
  5. A REVIEW OF HELIUM GAS TURBINE TECHNOLOGY FOR HIGH-TEMPERATURE GAS-COOLED REACTORS Archived 26 April 2012 at the Wayback Machine
  6. Keller, C. (1978). "Forty years of experience on closed-cycle gas turbines". Annals of Nuclear Energy. 5 (8–10): 405–422. doi:10.1016/0306-4549(78)90021-X.
  7. "Nuclear Power: Small modular reactors". Power Engineering . 7 June 2012. Retrieved 7 June 2012.[ permanent dead link ]
  8. 1 2 McDonald, C. F. (2012). "Helium turbomachinery operating experience from gas turbine power plants and test facilities". Applied Thermal Engineering. 44: 108–181. doi:10.1016/j.applthermaleng.2012.02.041.
  9. "ML-1 Mobile Power System: Reactor in a Box | Atomic Insights". Archived from the original on 22 July 2012. Retrieved 6 June 2012.
  10. IAEA Technical Committee Meeting on "Gas Turbine Power Conversion Systems for Modular HTGRs" [ permanent dead link ], held from 14–16 November 2000 in Palo Alto, California. International Atomic Energy Agency, Vienna (Austria). Technical Working Group on Gas-Cooled Reactors. IAEA-TECDOC--1238, pp:102-113 [ permanent dead link ]
  11. Introduction to Flibe Energy: YouTube Video (~20 min) and PDF Archived 5 April 2012 at the Wayback Machine of slides used
  12. Introduction to Gas Turbines for Non-Engineers (see page 5)
  13. V. Dostal, M.J. Driscoll, P. Hejzlar, "Archived copy" (PDF). Archived from the original (PDF) on 27 December 2010. Retrieved 7 December 2011.{{cite web}}: CS1 maint: archived copy as title (link)MIT-ANP-Series, MIT-ANP-TR-100 (2004)
  14. Sandia National Laboratories: Supercritical CO2-Brayton Cycle