Bureau of Mines Progress in Developing Open and Closed-Cycle Coal-Burning Gas Turbine Power Plants

1966 ◽  
Vol 88 (4) ◽  
pp. 313-320 ◽  
Author(s):  
J. Smith ◽  
D. C. Strimbeck ◽  
N. H. Coates ◽  
J. P. McGee

Closed-cycle developments include tests of a turbocompressor with hydrodynamic gas bearings. The working fluid is inert gas, with turbine inlet temperatures to 1600 F. A refractory-metal turbine for tests at 1950 F is described. Open-cycle operations for 1963 hours with turbine blades specially designed to resist erosion by coal ash particles are described. Estimated life of the rotor and stator blading was 20,000 and 5000 hours, respectively. Efforts to increase blade life by reducing the amount of ash entering the turbine through improvements in combustion and ash separation systems are described.

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Emmanuel O. Osigwe ◽  
Arnold Gad-Briggs ◽  
Theoklis Nikolaidis ◽  
Pericles Pilidis ◽  
Suresh Sampath

Abstract As demands for clean and sustainable energy renew interests in nuclear power to meet future energy demands, generation IV nuclear reactors are seen as having the potential to provide the improvements required for nuclear power generation. However, for their benefits to be fully realized, it is important to explore the performance of the reactors when coupled to different configurations of closed-cycle gas turbine power conversion systems. The configurations provide variation in performance due to different working fluids over a range of operating pressures and temperatures. The objective of this paper is to undertake analyses at the design and off-design conditions in combination with a recuperated closed-cycle gas turbine and comparing the influence of carbon dioxide and nitrogen as the working fluid in the cycle. The analysis is demonstrated using an in-house tool, which was developed by the authors. The results show that the choice of working fluid controls the range of cycle operating pressures, temperatures, and overall performance of the power plant due to the thermodynamic and heat properties of the fluids. The performance results favored the nitrogen working fluid over CO2 due to the behavior CO2 below its critical conditions. The analyses intend to aid the development of cycles for generation IV nuclear power plants (NPPs) specifically gas-cooled fast reactors (GFRs) and very high-temperature reactors (VHTRs).


Author(s):  
V.D. Molyakov ◽  
B.A. Kunikeev ◽  
N.I. Troitskiy

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.


Author(s):  
James H. Anderson

Ocean thermal energy plants are thermal power plants that use warm ocean surface water as a source of heat and cold seawater from the deep ocean as a heat sink. A historical perspective along with the development of the technology will be presented. A short description describing the subtle differences between OTEC and fossil and nuclear plants will be presented. Open cycle OTEC and closed cycle OTEC will be described with a focus on the influence of choice of working fluid on the design of a plant. Various working fluids could be selected for use in closed cycle OTEC plants. A review and comparison of potential working fluids will address the advantages and disadvantages of the individual fluids. Their characteristics along with a comparison to water as a working fluid in open cycle OTEC will be explained.


Author(s):  
R. Tom Sawyer

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.


2002 ◽  
Vol 124 (06) ◽  
pp. 50-52
Author(s):  
Lee Longston

This article focuses on gas turbines that were produced in 2001 spanning a wide range of capacities. As the engineer's most versatile energy converters, gas turbines producing thrust power continued in 2001 to propel most of the world's aircraft, both military and commercial. The largest commercial jet engines today can produce as much as 120,000 pounds thrust, or some 534,000 Newton. More natural gas pipeline capacity will be added to feed the surge in gas-driven electric power plants that have been corning online in the United States and other parts of the world. The gas turbine may come to be used in a new, commercially promising closed-cycle configuration. A South African company has been working on plans to build and test a prototype of a closed-cycle electric power gas turbine, which uses helium gas as the working fluid and a helium-cooled nuclear reactor to provide heat to power the cycle. If the gas turbine-nuclear reactor power plant is successful, the gas turbine may be the key to yet another energy conversion device, as it has been with record-setting numbers of combined-cycle plants installed worldwide.


Author(s):  
Emmanuel O. Osigwe ◽  
Arnold Gad-Briggs ◽  
Theoklis Nikolaidis ◽  
Pericles Pilidis ◽  
Suresh Sampath

One major challenge to the accurate development of performance simulation tool for component-based nuclear power plant engine models is the difficulty in accessing component performance maps; hence, researchers or engineers often rely on estimation approach using various scaling techniques. This paper describes a multi-fluid scaling approach used to determine the component characteristics of a closed-cycle gas turbine plant from an existing component map with their design data, which can be applied for different working fluids as may be required in closed-cycle gas turbine operations to adapt data from one component map into a new component map. Each component operation is defined by an appropriate change of state equations which describes its thermodynamic behavior, thus, a consideration of the working fluid properties is of high relevance to the scaling approach. The multi-fluid scaling technique described in this paper was used to develop a computer simulation tool called GT-ACYSS, which can be valuable for analyzing the performance of closed-cycle gas turbine operations with different working fluids. This approach makes it easy to theoretically scale existing map using similar or different working fluids without carrying out a full experimental test or repeating the whole design and development process. The results of selected case studies show a reasonable agreement with available data.


Author(s):  
Ali Afrazeh ◽  
Hiwa Khaledi ◽  
Mohammad Bagher Ghofrani

A gas turbine in combination with a nuclear heat source has been subject of study for some years. This paper describes the advantages of a gas turbine combined with an inherently safe and well-proven nuclear heat source. The design of the power conversion system is based on a regenerative, non-intercooled, closed, direct Brayton cycle with high temperature gas-cooled reactor (HTGR), as heat source and helium gas as the working fluid. The plant produces electricity and hot water for district heating (DH). Variation of specific heat, enthalpy and entropy of working fluid with pressure and temperature are included in this model. Advanced blade cooling technology is used in order to allow for a high turbine inlet temperature. The paper starts with an overview of the main characteristics of the nuclear heat source, Then presents a study to determine the specifications of a closed-cycle gas turbine for the HTGR installation. Attention is given to the way such a closed-cycle gas turbine can be modeled. Subsequently the sensitivity of the efficiency to several design choices is investigated. This model is developed in Fortran.


Author(s):  
James K. La Fleur

In May of 1960 La Fleur Enterprises, later to become The La Fleur Corporation, undertook the design of a closed-cycle gas turbine utilizing helium as a working fluid. The useful output of this machine was to be in the form of a stream of helium bled from the last stage of the compressor. This stream was to be used in a low-temperature refrigeration cycle (not described in this paper) and would be returned to the compressor inlet at approximately ambient temperature and at compressor-inlet pressure. The design of this machine was completed by the end of 1960 and construction was initiated immediately. The unit was completed and initial tests were made in the Spring of 1962. This paper covers the design philosophy as it affected the conceptual and preliminary design phases of the project and describes briefly the design of the various components. Photographs of these components and a flow schematic are included.


1968 ◽  
Vol 72 (696) ◽  
pp. 1087-1094 ◽  
Author(s):  
F. J. Bayley ◽  
A. B. Turner

It is well known that the performance of the practical gas turbine cycle, in which compression and expansion are non-isentropic, is critically dependent upon the maximum temperature of the working fluid. In engines in which shaft-power is produced the thermal efficiency and the specific power output rise steadily as the turbine inlet temperature is increased. In jet engines, in which the gas turbine has so far found its greatest success, similar advantages of high temperature operation accrue, more particularly as aircraft speeds increase to utilise the higher resultant jet velocities. Even in high by-pass ratio engines, designed specifically to reduce jet efflux velocities for application to lower speed aircraft, overall engine performance responds very favourably to increased turbine inlet temperatures, in which, moreover, these more severe operating conditions apply continuously during flight, and not only at maximum power as with more conventional cycles.


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