Performance Potential of an Advanced Nuclear Gas Turbine/Cogeneration System (HTGR-GT/C)

Volume 3: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations

1996

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Many variants of the nuclear closed Brayton cycle (NCBC) power plant have been studied over the last five decades, the ultimate goal being the introduction of a high efficiency and environmentally acceptable plant for electrical power generation. With an indirect cycle (IDC) plant the thermal energy from a high temperature reactor (HTR) is transferred to the helium gas turbine power conversion system via an intermediate heat exchanger. Compared with previous direct cycle variants the decoupling of the prime-mover from the reactor has the following advantages, 1) configuration flexibility (eased congestion), 2) good component access, 3) non radioactive power conversion system, 4) ease of maintenance, 5) use of conventional equipment, 6) reduced development effort, and 7) eased adaptability to a fossil-fired source. In addition to being a more practical configuration, a major attribute for the IDC is that it is compatible with long-term plans for development of a high temperature nuclear heat source (NHS) currently underway in Japan. With a NHS in place a logical progression of the HTR would be to deploy a power generation version using an IDC helium gas turbine. This paper sheds new light on the nuclear gas turbine in that it is no longer at the forefront of gas cooled reactor application studies, but rather could be a beneficiary of work currently underway in Japan to develop a nuclear heat source for high temperature process heat. The performance and major features of a future NCBC plant concept are highlighted in this paper. Depending on the market forces prevailing in Asia for small nuclear plants, the NCBC with an indirect cycle helium gas turbine could be available for service around the year 2020.

Section: System Parametersmentioning

confidence: 99%

Section: Helium Circulatorsmentioning

confidence: 99%

The Indirect Cycle: A Logical and Practical Nuclear Gas Turbine Power Plant Concept

Volume 3: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations

1996

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“…The potential of MHR operation at much higher levels of temperature is well known (McDonald, 1986), but this is essentially viewed as afollow-on class of plants taking advantage of a commercial data base from the aforementioned steam cycle plant. The direct cycle gas turbine, operating at a temperature of 950°C (1742°F) has the potential for 50% efficiency when dry-cooled (McDonald, 1987). The stimulus for increasing the reactor outlet temperature to 950°C, however, has never come from the power generating sector,…”

Section: Plant Genesismentioning

confidence: 99%

Advanced Hybrid Gas Turbine Plant Concept for Electrical Power Generation and Alternate Transportation Fuels Production

Volume 3: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations

1991

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In long-term U.S. energy planning three major factors are paramount, (1) environmental considerations will play a major role in power plant design, (2) alternate (and cleaner burning) transportation fuels must be introduced to wean the country from dependence on imported oil, and (3) increasing reliance will be placed on indigenous resources, namely uranium and coal. It will likely take several decades for the above goals to be implemented on a large scale, and will surely necessitate the utilization of advanced technologies. A proposed advanced version of the modular helium reactor (MHR) has bi-modal operating capability in that it can be used for power generation, and the emission-free production of cleanburning fuels to meet transportation needs. The advanced hybrid MHR plant concept utilizes a direct cycle helium nuclear gas turbine for electrical power generation (with an efficiency potential of 50%), and in addition embodies an intermediate heat transport loop for high temperature process heat needed for the emission-free conversion of coal into future cleaner burning transportation fuels, namely methanol, synthetic natural gas, or hydrogen. The high grade sensible reject heat from both the prime-mover and process heat loop is ideally suited for desalination, and thus gives the plant capability for generating three revenue streams. This paper highlights an advanced very high temperature hybrid plant concept, and discusses the enabling technologies necessary to make such an energy complex a reality, perhaps in the first decade of the 21st century. Such a power generating and fuel production facility would be in concert with improved clean air goals, and the national security and economic advantages of making U.S. power and fuel supplies dependent only on indigenous resources. INTRODUCTIONCombined cycle gas turbines, using natural gas as their fuel and exhibiting efficiency values of over 50%, are being ordered in increasing numbers by U.S. utilities. It is projected that these plants will dominate the needed new capacity in the next two decades until the second generation of nuclear power plants has an impact on the energy scene. Today nuclear power represents 6% of the energy used in the U.S., and the next generation of plants, characterized by their modular construction, passive features, and inherently safe characteristics, will play a vital role in meeting increasing electricity demand in an environmentally acceptable manner. The full potential of nuclear power must be exploited if it is to offer a solution to both an improved environment and reduced national dependency on imported crude oil. The MHR, by virtue of its very high temperature capability, is the only type of reactor that can be used as a nuclear heat source in the conversion of coal into alternative cleaner burning transportation fuels. At the necessary reactor outlet temperature of 950°C (1 742°F) advantage can also be taken of a high efficiency direct cycle helium gas turbine for power generation, and this is a major theme of this paper.Be...

“…Many of the technologies necessary to make the gas turbine a reality have been reported previously (McDonald, 1987b) and will be highlighted only here. The HTGR reactor core, consisting of an assemblage of prismatic fuel elements and graphite moderator blocks, has the capability for very high temperature operation.…”

Section: Nuclear Heat Sourcementioning

confidence: 99%

Gas Turbine Power Plant Possibilities With a Nuclear Heat Source: Closed and Open Cycles

Volume 3: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations

1990

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With the capability of burning a variety of fossil fuels, giving high thermal efficiency, and operating with low emissions, the gas turbine is becoming a major prime-mover for a wide spectrum of applications. Almost three decades ago two experimental projects were undertaken in which gas turbines were actually operated with heat from nuclear reactors. In retrospect, these systems were ahead of their time in terms of technology readiness, and prospects of the practical coupling of a gas turbine with a nuclear heat source towards the realization of a high efficiency, pollutant free, dry-cooled power plant has remained a long-term goal, which has been periodically studied in the last twenty years. Technology advancements in both high temperature gas-cooled reactors, and gas turbines now make the concept of a nuclear gas turbine plant realizable. Two possible plant concepts are highlighted in this paper, (1) a direct cycle system involving the integration of a closed-cycle helium gas turbine with a modular high temperature gas cooled reactor (MHTGR), and (2) the utilization of a conventional and proven combined cycle gas turbine, again with the MHTGR, but now involving the use of secondary (helium) and tertiary (air) loops. The open cycle system is more equipment intensive and places demanding requirements on the very high temperature heat exchangers, but has the merit of being able to utilize a conventional combined cycle turbo-generator set. In this paper both power plant concepts are put into perspective in terms of categorizing the most suitable applications, highlighting their major features and characteristics, and identifying the technology requirements. The author would like to dedicate this paper to the late Professor Karl Bammert who actively supported deployment of the closed-cycle gas turbine for several decades with a variety of heat sources including fossil, solar, and nuclear systems.