Closed Cycle Gas Turbines: An ECAS Update — Part 1

1979 ◽  
Author(s):  
H. C. Daudet ◽  
C. A. Kinney
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
System Analysis ◽  
Public Utility ◽  
Department Of Energy ◽  
Closed Cycle ◽  
Study Program ◽  
Study Results

This paper presents a discussion of the significant results of a study program conducted for the Department of Energy to evaluate the potential for closed cycle gas turbines and the associated combustion heater systems for use in coal fired public utility power plants. Two specific problem areas were addressed: (a) the identification and analysis of system concepts which offer high overall plant efficiency consistent with low cost of electricity (COE) from coal-pile-to-bus-bar, and (b) the identification and conceptual design of combustor/heat exchanger concepts compatible for use as the cycle gas primary heater for those plant systems. The study guidelines were based directly upon the ground rules established for the ECAS studies to facilitate comparison of study results. Included is a discussion of a unique computer model approach to accomplish the system analysis and parametric studies performed to evaluate entire closed cycle gas turbine utility power plants with and without Rankine bottoming cycles. Both atmospheric fluidized bed and radiant/convective combustor /heat exchanger systems were addressed. Each incorporated metallic or ceramic heat exchanger technology. The work culminated in conceptual designs of complete coal fired, closed cycle gas turbine power plants. Critical component technology assessment and cost and performance estimates for the plants are also discussed.

scholarly journals The Role of the Recuperator in High Performance Gas Turbine Applications

1978 ◽  
Author(s):  
C. F. McDonald
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Performance ◽  
Waste Heat ◽  
Closed Cycle ◽  
Exhaust Waste Heat ◽  
Prime Movers

With soaring fuel costs and diminishing clean fuel availability, the efficiency of the industrial gas turbine must be improved by utilizing the exhaust waste heat by either incorporating a recuperator or by co-generation, or both. In the future, gas turbines for power generation should be capable of operation on fuels hitherto not exploited in this prime-mover, i.e., coal and nuclear fuel. The recuperative gas turbine can be used for open-cycle, indirect cycle, and closed-cycle applications, the latter now receiving renewed attention because of its adaptability to both fossil (coal) and nuclear (high temperature gas-cooled reactor) heat sources. All of these prime-movers require a viable high temperature heat exchanger for high plant efficiency. In this paper, emphasis is placed on the increasingly important role of the recuperator and the complete spectrum of recuperative gas turbine applications is surveyed, from lightweight propulsion engines, through vehicular and industrial prime-movers, to the large utility size nuclear closed-cycle gas turbine. For each application, the appropriate design criteria, types of recuperator construction (plate-fin or tubular etc.), and heat exchanger material (metal or ceramic) are briefly discussed.

Applying Combined Pinch and Exergy Analysis to Closed-Cycle Gas Turbine System Design

1995 ◽  
Vol 117 (1) ◽  
pp. 47-52 ◽  
Author(s):  
V. R. Dhole ◽  
J. P. Zheng
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Exergy Analysis ◽  
Energy Savings ◽  
Design Guidelines ◽  
Closed Cycle ◽  
Practical Design ◽  
Pinch Technology

Pinch technology has developed into a powerful tool for thermodynamic analysis of chemical processes and associated utilities, resulting in significant energy savings. Conventional pinch analysis identifies the most economical energy consumption in terms of heat loads and provides practical design guidelines to achieve this. However, in analyzing systems involving heat and power, for example, steam and gas turbines, etc., pure heat load analysis is insufficient. Exergy analysis, on the other hand, provides a tool for heat and power analysis, although at times it does not provide clear practical design guidelines. An appropriate combination of pinch and exergy analysis can provide practical methodology for the analysis of heat and power systems. The methodology has been successfully applied to refrigeration systems. This paper introduces the application of a combined pinch and exergy approach to commercial power plants with a demonstration example of a closed-cycle gas turbine (CCGT) system. Efficiency improvement of about 0.82 percent (50.2 to 51.02 percent) can be obtained by application of the new approach. More importantly, the approach can be used as an analysis and screening tool for the various design improvements and is generally applicable to any commercial power generation facility.

The Efficiency of Closed-Cycle Gas Turbines Controlled by Different Methods and Programs

2020 ◽  
pp. 51-63
Author(s):  
V.D. Molyakov ◽  
B.A. Kunikeev ◽  
N.I. Troitskiy
Keyword(s):  
Gas Turbine ◽  
Heat Exchangers ◽  
Gas Turbines ◽  
Power Plants ◽  
Control Method ◽  
Low Pressure ◽  
Working Fluid ◽  
Closed Cycle ◽  
Efficient Operation ◽  
Pressure Compressor

Closed-cycle gas turbine units can be used as power plants for advanced nuclear power stations, spacecraft, ground, surface and underwater vehicles. The purpose and power capacity of closed gas turbine units (CGTU) determine their specific design schemes, taking into account efficient operation of the units both in the nominal (design) mode and in partial power modes. Control methods of both closed and open gas turbine units depend on the scheme and design of the installation but the former differ from the latter mainly in their ability to change gas pressure at the entrance to the low-pressure compressor. This pressure can be changed by controlling the mass circulating in the CGTU circuit, adding or releasing part of the working fluid from the closed system as well as by internal bypassing of the working fluid. At a constant circulating mass in the single-shaft CGTU, the temperature of the gas before the turbines and the shaft speed can be adjusted depending on the type of load. The rotational speed of the turbine shaft, blocked with the compressor, can be adjusted in specific ways, such as changing the cross sections of the flow of the impellers. At a constant mass of the working fluid, the pressure at the entrance to the low-pressure compressor varies depending on the control program. The efficiency of the CGTU in partial power modes depends on the installation scheme, control method and program. The most economical control method is changing the pressure in the circuit. Extraction of the working fluid into special receivers while maintaining the same temperature in all sections of the unit leads to a proportional decrease in the density of the working fluid in all sections and the preservation of gas-dynamic similarity in the nodes (compressors, turbines and pipelines). Specific heat flux rates, and therefore, temperatures change slightly in heat exchangers. As the density decreases, heat fluxes change, as the heat transfer coefficient decreases more slowly than the density of the working fluid. With a decrease in power, this leads to a slight increase in the degree of regeneration and cooling in the heat exchangers. The underestimation of these phenomena in the calculations can be compensated by the underestimation of the growth of losses in partial power modes.

scholarly journals Large Helium Turbines for Nuclear Power Plants

1970 ◽  
Author(s):  
W. Endres
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
State Of The Art ◽  
Short Review ◽  
The State ◽  
Closed Cycle ◽  
The Future

A short review of the state-of-the-art of the closed cycle gas turbine technology is given and the future requirements for large helium turbines are described. The necessary development of components and turbine sizes is outlined. In a second part of the paper the configuration and layout of power plants with gas turbines are discussed.

scholarly journals Evaluation Method for Closed Cycle Gas Turbines in Cogeneration Applications

1980 ◽  
Author(s):  
H. C. Daudet ◽  
S. W. Trimble
Keyword(s):  
Gas Turbines ◽  
Evaluation Method ◽  
Electrical Power ◽  
Industrial Process ◽  
District Heating ◽  
Department Of Energy ◽  
Evaluation Procedure ◽  
Closed Cycle ◽  
Study Program ◽  
Capital Costs

The utilization of coal-fired closed cycle gas turbine/atmospheric fluidized bed (CCGT/AFB) electrical power generating plants for cogeneration was investigated in a Department of Energy-sponsored study program conducted by The Garrett Corporation. Both industrial process and district heating and cooling applications in the 10- to 50-MWe range were considered. An evaluation procedure was developed in which cogeneration plant capital, operating, maintenance, and financing costs are calculated and compared with the cost of providing equivalent services by traditional methods. Computer optimized conceptual designs of the CCGT/AFB plants were prepared, and performance and capital costs were estimated. A broad spectrum of applications including towns, military bases, universities, and industrial processes was surveyed. This paper presents the general evaluation procedure, typical plant designs, and the evaluation of two applications.

Heat Exchanger Design Considerations for Gas Turbine HTGR Power Plant

1977 ◽  
Vol 99 (2) ◽  
pp. 237-245 ◽  
Author(s):  
C. F. McDonald ◽  
T. Van Hagan ◽  
K. Vepa
Keyword(s):  
Heat Exchanger ◽  
Power Plant ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Conversion ◽  
Structural Safety ◽  
Working Fluid ◽  
Closed Cycle ◽  
High Degree ◽  
Cycle Efficiency

The Gas Turbine High Temperature Gas Cooled Reactor (GT-HTGR) power plant combines the existing design HTGR core with a closed-cycle helium gas turbine power conversion system directly in the reactor primary circuit. Unlike open-cycle gas turbines where the recuperative heat exchanger is an optional component, the high cycle efficiency of the nuclear closed-cycle gas turbine is attributable to a high degree to the incorporation of the recuperator (helium-to-helium) and precooler (helium-to-water) exchangers in the power conversion loop. For the integrated plant configuration, a nonintercooled cycle with a high degree of heat recuperation was selected on the basis of performance and economic optimization studies. A recuperator of high effectiveness was chosen because it significantly reduces the optimum pressure ratio (for maximum cycle efficiency), and thus reduces the number of compressor and turbine stages for the low molecular weight, high specific heat, helium working fluid. Heat rejection from the primary system is effected by a helium-to-water precooler, which cools the gas to a low level prior to compression. The fact that the rejection heat is derived from the sensible rather than the latent heat of the cycle working fluid results in dissipation over a wide band of temperature, the high average rejection temperature being advantageous for either direct air cooling or for generation of power in a waste heat cycle. The high heat transfer rates in the recuperator (3100 MWt) and precooler (1895 MWt), combined with the envelope restraints associated with heat exchanger integration in the prestressed concrete reactor vessel, require the use of more compact surface geometries than in contemporary power plant steam generators. Various aspects of surface geometry, flow configuration, mechanical design, fabrication, and integration of the heat exchangers are discussed for a plant in the 1100 MWe class. The influence of cycle parameters on the relative sizes of the recuperator and precooler are also presented. While the preliminary designs included are not meant to represent final solutions, they do embody features that satisfy many of the performance, structural, safety, and economic requirements.

Advanced Particle Control for Coal-Based Power Generation Systems

1989 ◽  
Author(s):  
Steven J. Bossart
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Particle Deposition ◽  
Power Plants ◽  
Turbine Blades ◽  
Combined Cycle ◽  
Department Of Energy ◽  
Power Generation Systems

The Morgantown Energy Technology Center (METC) of the U.S. Department of Energy (DOE) is actively sponsoring research to develop coal-based power generation systems that use coal more efficiently and economically and with lower emissions than conventional pulverized-coal power plants. Some of the more promising of the advanced coal-based power generation systems are shown in Figure 1: pressurized fluidized-bed combustion combined-cycle (PFBC), integrated gasification combined-cycle (IGCC), and direct coal-fueled turbine (DCFT). These systems rely on gas turbines to produce all or a portion of the electrical power generation. An essential feature of each of these systems is the control of particles at high-temperature and high-pressure (HTHP) conditions. Particle control is needed in all advanced power generation systems to meet environmental regulations and to protect the gas turbine and other major system components. Particles can play a significant role in damaging the gas turbine by erosion, deposition, and corrosion. Erosion is caused by the high-speed impaction of particles on the turbine blades. Particle deposition on the turbine blades can impede gas flow and block cooling air. Particle deposition also contributes to corrosive attack when alkali metal compounds adsorbed on the particles react with the gas turbine blades. Incorporation of HTHP particle control technologies into the advanced power generation systems can reduce gas turbine maintenance requirements, increase plant efficiency, reduce plant capital cost, lower the cost of electricity, reduce wastewater treatment requirements, and eliminate the need for post-turbine particle control to meet New Source Performance Standards (NSPS) for particle emissions.

scholarly journals Application of RQL Coal Combustor Technology to Large Utility Gas Turbines

1993 ◽  
Author(s):  
C. Wilkes ◽  
R. A. Wenglarz ◽  
P. J. Hart ◽  
H. C. Mongia
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Heat Engine ◽  
Combined Cycle ◽  
Pulverized Coal ◽  
Department Of Energy ◽  
Cycle Performance ◽  
Proof Of Concept ◽  
Combustion System

This paper describes the application of Allison’s rich-quench-lean (RQL) coal combustor technology to large utility gas turbines in the 100 MWe+ class. The RQL coal combustor technology was first applied to coal derived fuels in the 1970s and has been under development since 1986 as part of a Department of Energy (DOE)-sponsored heat engine program aimed at proof of concept testing of coal-fired gas turbine technology. The 5 MWe proof of concept engine/coal combustion system was first tested on coal water slurry (CWS); it is now being prepared for testing on dry pulverized coal. A design concept to adapt the RQL coal combustor technology developed under the DOE program to large utility-sized gas turbines has been proposed for a Clean Coal V program. The engine and combustion system modifications required for application to coal-fueled combined cycle power plants using 100 MWe+ gas turbines are described. Estimates for emissions and cycle performance are given. Included are comparisons with a conventional pulverized coal plant that illustrates the advantages of incorporating a gas turbine on cycle efficiency and emission rate.

The Closed Cycle Gas Turbine, the Most Efficient Turbine Burning any Fuel

1984 ◽  
Author(s):  
R. Tom Sawyer
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Main Part ◽  
Closed Cycle ◽  
Efficient Type ◽  
Open Cycle ◽  
Burning Coal

The are two types of gas turbines. The open cycle is very well known as for example the JET. The closed cycle in the U.S.A. is just starting to be well known. In Europe the closed cycle gas turbine has been used in power plants, especially in Germany and have been very efficient burning coal. I am going to concentrate on the CCGT - Closed Cycle Gas Turbine as it is the most efficient type of turbine. First I will give a brief report written by Dr. Curt Keller. Then the main part of this paper will give more details about the closed cycle gas turbine (CCGT) using various fuels.

scholarly journals Rapid Positive Load Changes by Gas Injection in Closed Gas Turbine Cycles

1978 ◽  
Author(s):  
H. U. Frutschi
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Gas Injection ◽  
Load Reduction ◽  
Control Methods ◽  
Power Demand ◽  
Closed Cycle ◽  
Autonomous Operation

Spontaneous response to power demand is essential during autonomous operation of power plants. In this case, only control principles with negligible negative momentary effects can be employed. A further requirement is a good part-load efficiency. After a brief description of the most important control methods of closed-cycle gas turbines, the dynamic behavior of the cycle during gas injection for positive load changes is analyzed. A very attractive method is inter-compressor injection from an intermediate pressure reservoir which can be charged from the compressor exit during load reduction. Based on these results, a control system for closed-cycle gas turbine employing gas injection is presented.

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