scholarly journals A Semiclosed Cycle Gas Turbine With Carbon Dioxide-Argon as Working Fluid

Author(s):  
Inaki Ulizar ◽  
Pericles Pilidis

This paper describes the performance analysis of a semi closed cycle gas turbine. The working fluid is carbon dioxide and the fuel is low heating value gas synthesised from coal. The objective of the machine is to produce clean electricity with the smallest efficiency penalty. Firstly the thermodynamic properties of the gases in the cycle were obtained as a function of temperature and pressure. Then two performance simulation codes were developed. These have the ability of simulating different configurations of open, closed and semi-closed cycles. The first code was used for cycle optimisation and the second for off-design studies. The design and off-design performance of the machine are predicted. The production of clean electricity will be at the expense of a lower efficiency compared with current equipment. Finally, some critical issues for the development of such a gas turbine are identified.

1997 ◽  
Vol 119 (3) ◽  
pp. 612-616 ◽  
Author(s):  
I. Ulizar ◽  
P. Pilidis

This paper describes the performance analysis of a semiclosed-cycle gas turbine. The working fluid is carbon dioxide and the fuel is low heating value gas synthesized from coal. The objective of the machine is to produce clean electricity with the smallest efficiency penalty. First, the thermodynamic properties of the gases in the cycle were obtained as a function of temperature and pressure. Then two performance simulation codes were developed. These have the ability of simulating different configurations of open, closed, and semiclosed cycles. The first code was used for cycle optimization and the second for off-design studies. The design and off-design performances of the machine are predicted. The production of clean electricity will be at the expense of a lower efficiency compared with current equipment. Finally, some critical issues for the development of such a gas turbine are identified.


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):  
Anthony J. B. Jackson ◽  
Alcides Codeceira Neto ◽  
Matthew W. Whellens ◽  
Harry Audus

The world’s main atmospheric “greenhouse gas” is carbon dioxide (CO2). The CO2 content of the atmosphere continues to rise due to increasing world demand for energy, and thus further means are needed to achieve its abatement. Most gas turbine powered electricity generating plants use hydro-carbon fuels and this inevitably produces CO2 in the engine exhaust. This paper discusses a scheme for concentrating the gas turbine exhaust CO2, thus facilitating its extraction. The scheme is a gas turbine operating synchronously in closed cycle, with CO2 as the working fluid. The additional CO2 and water produced in the combustion process are removed continuously. CO2 and air have substantially different gas properties. This significantly affects the performance of the gas turbine. It is shown that any gas turbine designed to use air, and operating synchronously, would need considerable modifications to its compressor and combustion systems to use carbon dioxide as its working fluid.


Author(s):  
Ian G. Wright ◽  
John Stringer

Indirectly-fired cycles provide one means of using a fuel other than natural gas or distillates of various purities to generate power using a gas turbine. In a closed cycle, the fuel typically is used to heat a clean working fluid which is then expanded through a gas turbine, after which it is cooled and recompressed before being recirculated through the heating circuit. In an open cycle, the heated working fluid (usually air) is exhausted to the atmosphere after expansion in the turbine and passage through heat recovery devices. In both cases, the temperature of the working fluid may be boosted before entry to the turbine by supplementary firing of a premium fuel such as natural gas in a topping combustor. A major advantage of such indirectly-fired cycles is that the concerns arising from the use of a dirty fuel in other advanced cycles are confined to the fireside surfaces of the heat exchange equipment, whereas the gas turbine is exposed to a relatively benign environment. One limitation of such systems is that the emissions problems are the same as for a conventional coal-fired boiler although, on an power output-normalized basis, the emissions from an indirectly-fired cycle may be lower. The requirements of the potential candidate materials for the various components in the circuit are discussed, and the critical issues for each are identified.


2000 ◽  
Vol 122 (3) ◽  
pp. 437-441 ◽  
Author(s):  
Inaki Ulizar ◽  
Pericles Pilidis

This paper outlines the handling of a semi-closed cycle gas turbine, its working fluid is carbon dioxide and the fuel is low heating value gas from coal; however, at startup air and natural gas are used. The objective of the machine is to produce clean electricity with the smallest efficiency penalty. Many aspects of the operation of the engine are examined in this paper; these include starting requirements, stator vane and bleed valve scheduling, and the working fluid transition from air to carbon dioxide. Other features highlighted are the compressor operating lines and surge margins. The present paper describes the salient features of the three main stages into which the engine operation has been divided. These stages are: startup to synchronous idle, change of working fluid (from air to Carbon Dioxide-Argon) and fuel (from natural gas to coal synthetic gas) at synchronous idle, and part load operation. Preliminary findings show that engine handling can be carried out effectively with variable stators. This is possible because of the two-shaft gas generator. Another point of interest is the large increase of corrected speed relative to rotational speed experienced when the working fluid changes from air to carbon dioxide. In general the control of the engine does not seem to present any insurmountable problems despite the complexities arising from the need to change working fluid and fuel. [S0742-4795(00)02903-3]


Author(s):  
Inaki Ulizar ◽  
Pericles Pilidis

This paper outlines the handling of a semi closed cycle gas turbine, its working fluid is carbon dioxide and the fuel is low heating value gas from coal. At startup however, air and natural gas are used. The objective of the machine is to produce clean electricity with the smallest efficiency penalty. Many aspects of the operation of the engine are examined here; these include starting requirements, stator vane and bleed valve scheduling and the working fluid transition from air to carbon dioxide. Other features highlighted are the compressor operating lines and surge margins. The present paper describes the salient features of the three main stages into which the engine operation has been divided. These stages are: startup to synchronous idle, change of working fluid (from air to Carbon Dioxide-Argon) and fuel (from natural gas to coal synthetic gas) at synchronous idle and part load operation. Preliminary findings show that engine handling can be carried out effectively with variable stators. This is possible because of the two shaft gas generator. Another point of interest is the large increase of corrected speed relative to rotational speed experienced when the working fluid changes from air to carbon dioxide. In general the control of the engine does not seem to present any insurmountable problems despite the complexities arising from the need to change working fluid and fuel.


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.


Author(s):  
L. D. Stoughton ◽  
T. V. Sheehan

A nuclear power plant is proposed which combines the advantages of a liquid metal fueled reactor with those inherent in a closed cycle gas turbine. The reactor fuel is a solution of uranium in molten bismuth which allows for unlimited burn-up with continuous fuel make-up and processing. The fuel can either be contained in a graphite core structure or circulated through an external heat exchanger. The cycle working fluid is an inert gas which is heated by the reactor fuel before entering the turbine. A 15 MW closed cycle gas turbine system is shown to illustrate the application of this reactor.


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