5632143 Gas turbine system and method using temperature control of the exhaust gas entering the heat recovery cycle by mixing with ambient air

1997 ◽  
Vol 17 (12) ◽  
pp. XV-XVI
Keyword(s):  
Gas Turbine ◽  
Temperature Control ◽  
Heat Recovery ◽  
Ambient Air ◽  
Exhaust Gas ◽  
Recovery Cycle

A New Calculation Approach to the Energy Balance of a Gas Turbine Including a Study of the Impact of the Uncertainty of Measured Parameters

2005 ◽  
Author(s):  
Helmer G. Andersen ◽  
Pen-Chung Chen
Keyword(s):  
Energy Balance ◽  
Gas Turbine ◽  
Control Volume ◽  
Ambient Air ◽  
Energy Balance Equation ◽  
Inlet Temperature ◽  
Exhaust Gas ◽  
Gas Composition ◽  
Intake Flow ◽  
The Impact

Computing the solution to the energy balance around a gas turbine in order to calculate the intake mass flow and the turbine inlet temperature requires several iterations. This makes hand calculations very difficult and, depending on the software used, even causes significant calculation times on PCs. While this may not seem all that important considering the power of today’s personal computers, the approach described in this paper presents a new way of looking at the gas turbine process and the resulting simplifications in the calculations. This paper offers a new approach to compute the energy balance around a gas turbine. The energy balance requires that all energy flows going into and out of the control volume be accounted for. The difficulty of the energy balance equation around a gas turbine lies in the fact that the exhaust gas composition is unknown as long as the intake flow is unknown. Thus, a composition needs to be assumed when computing the exhaust gas enthalpy. This allows the calculation of the intake flow, which in turn provides a new exhaust gas composition, and so forth. By viewing the exhaust gas as a flow consisting of ambient air and combusted fuel, the described iteration can be avoided. The study presents the formulation of the energy balance applying this approach and looks at the accuracy of the result as a function of the inaccuracy of the input parameters. Furthermore, solutions of the energy balance are presented for various process scenarios, and the impact of the uncertainty of key process parameter is analyzed.

On the Effect of Swirl Flow of Gas Turbine Exhaust Gas in an Inlet Duct of Heat Recovery Steam Generator

2002 ◽  
Vol 124 (3) ◽  
pp. 496-502 ◽  
Author(s):  
B. E. Lee ◽  
S. B. Kwon ◽  
C. S. Lee
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Swirl Flow ◽  
Exhaust Gas ◽  
Heat Recovery Steam Generator ◽  
Gas Turbine Exhaust ◽  
Duct Burner ◽  
Turbine Exhaust ◽  
Inlet Duct

Computational and experimental studies are performed to investigate the effect of swirl flow of gas turbine exhaust gas (GTEG) in an inlet duct of a heat recovery steam generator (HRSG). A supplemental-fired HRSG is chosen as the model studied because the uniformity of the GTEG at the inlet plane of the duct burner is essential in such applications. Both velocity and oxygen distributions are investigated at the inlet plane of the duct burner installed in the middle of the HRSG transition duct. Two important parameters, the swirl angle of GTEG and the momentum ratio of additional air to GTEG, are chosen for the investigation of mixing between the two streams. It has been found that a flow correction device (FCD) is essential to provide a uniform gas flow distribution at the inlet plane of the duct burner.

scholarly journals Comparison Method for Complex Cycle Analysis

1986 ◽  
Author(s):  
R. Cai
Keyword(s):  
Theoretical Analysis ◽  
Gas Turbine ◽  
Heat Recovery ◽  
Comparison Method ◽  
Combined Cycle ◽  
Performance Estimation ◽  
Correction Factors ◽  
Recovery Cycle ◽  
Thermodynamic Performance ◽  
Gas Turbine Cycle

A new methodology is developed for the performance estimation of complex cycles such as conventional combined cycle, steam injected gas turbine cycle, AFBC coal burned exhaust heated combined cycle, alternative fuel heat recovery cycle and so on. The basic idea of this method is to compare the performance of the complex cycles with the well-known performance of the main sub-cycle (for example, the gas turbine cycle) in some way and then add simple correction factors if necessary. With such approach, the thermodynamic performance of complex cycles can be estimated and expressed very simply, directly and conveniently. The abovementioned complex cycles have been analyzed successfully by this method; the obtained results are brief and concise, and compared well with practical data and other detailed theoretical analysis results.

Thermodynamic Analysis of New Combination of Supercharged Boiler Cycle and Heat Recovery Cycle for Power Generation

1996 ◽  
Vol 118 (2) ◽  
pp. 453-460 ◽  
Author(s):  
M. Akiba ◽  
E. A. Thani
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Pressure Ratio ◽  
New Combination ◽  
Gas Temperature ◽  
Recovery Cycle ◽  
Excess Air ◽  
Mean Temperature ◽  
The Mean ◽  
Cycle Efficiency

The aim of this paper is to study the performance of a new combination of supercharged boiler–gas turbine cycle, which is expected to reduce the cooling air in the combustor and heat recovery cycle, from a thermodynamic point of view. Two designs of this cycle were adopted and the influences of various operating parameters, such as compressor pressure ratio, ambient temperature, inlet gas temperature of gas turbine, percentage of excess air, and number of feedwater heaters, were studied. Three techniques were applied to increase the overall cycle efficiency: first, increasing the mean temperature of heat supplied by increasing the inlet gas temperature of the gas turbine; second, decreasing the mean temperature of heat rejected through a heat recovery cycle; and third, reducing the percentage of excess air in the supercharged boiler. A performance comparison between the adopted cycles and a conventional heat recovery cycle was made. The results show that there is an improvement in overall cycle efficiency of about 8.5–9.5 percent with the first design of the adopted cycle over the conventional heat recovery cycle, while an improvement of overall cycle efficiency of about 1.0–5.5 percent is obtained for the second design.

Development of a Thermal Approach to Optimize the Waste Heat Utilisation From an Existing Gas Turbine Station Without Heat Recovery System

2003 ◽  
Author(s):  
Guyh Dituba Ngoma ◽  
Amsini Sadiki
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Waste Heat ◽  
Finned Tube ◽  
Pressure Tube ◽  
Exhaust Gas ◽  
Static System ◽  
Recovery System ◽  
Heat Recovery System ◽  
Tube Banks

The present work deals with a numerical simulation of a flow in finned tube banks arranged behind a gas turbine. Three models of dual-pressure tube systems are developed and analyzed in order to predict the static system performances by optimizing the utilization of the exhaust gas from an existing gas turbine without heat recovery system. For more precise modeling, the theoretical analysis of finned tube banks systems is based on the non-linear conservation equations of mass, momentum and energy. Simulations are accomplished to prove the effectiveness of the present work in performance prediction of the dual-pressure tube systems. The obtained results clearly show the necessity to take into account all relevant physical phenomena in the simulation of flows in and across finned tube banks installed behind a gas turbine. The results also reveal the different operating behavior of the developed models considering combined effects of the exhaust gas parameters and the tube geometries.

scholarly journals Process Air Extraction From a Gas Turbine

1967 ◽  
Author(s):  
P. C. Husen
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Exhaust Gas ◽  
Petrochemical Plant

This paper describes a unique and successful application of a gas turbine in a petrochemical plant. In addition to driving a hydrocarbon compressor and furnishing hot exhaust gas for waste-heat recovery, the gas turbine furnishes process air at approximately 50 psig. A larger gas turbine than required by compressor load was purchased to provide the necessary air.

Modified Rankine HRSG Beats Triple-Pressure System

1996 ◽  
Author(s):  
Peter Eisenkolb ◽  
Martin Pogoreutz ◽  
Hermann Halozan
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Fossil Fuels ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Pressure System ◽  
Exergy Losses

Gas-fired combined cycle power plants (CCP) are presently the most efficient systems for producing electricity with fossil fuels. Gas turbines have been and are being improved remarkably during the last years; presently they achieve efficiencies of more than 38% and gas turbine outlet temperatures of up to 610°C. These high outlet temperatures require modifications and improvements of heat recovery steam generators (HRSG). Presently dual pressure HRSGs are most commonly used in combined cycle power stations. The next step seems to be the triple-pressure HRSG to be able to utilise the high gas turbine outlet temperatures efficiently and to reduce exergy losses caused by the heat transfer between exhaust gas and the steam cycle. However, such triple-pressure systems are complicated considering parallel tube bundles as well as start up operation and load changes. For that reason an attempt has been made to replace such multiple pressure systems by a modified Rankine cycle with only a single-pressure level. In the case of the same total heat transfer surfaces this innovative single-pressure system achieves approximately the same efficiency as the triple-pressure system. By optimising the heat recovery from the exhaust gas to the steam/water cycle, i.e. minimising exergy losses, the stack temperature is much higher. Increasing the heat transfer surfaces means a decrease of the stack temperature and a further improvement of the overall CCP-efficiency. Therefore one has to be aware that the proposed system offers advantages not only in the case of a foreseeable increase of gas turbine outlet temperatures but also for presently available gas turbines. Using existing highly efficient gas turbines and subcritical steam conditions, power plants with this proposed Eisenkolb Single Pressure (ESP_CCP) heat recovery steam generator achieve thermal efficiencies of about 58.7% (LHV).

Modeling and Cost Optimization of Combined Cycle Heat Recovery Generator Systems

2003 ◽  
Author(s):  
Yongjun Zhao ◽  
Hongmei Chen ◽  
Mark Waters ◽  
Dimitri N. Mavris
Keyword(s):  
Power Plant ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Heat Recovery ◽  
Combined Cycle ◽  
System Level ◽  
Exhaust Gas ◽  
Heat Recovery Steam Generator ◽  
Turbine Engine ◽  
Investment Cost

The combined cycle power plant is made up of three major systems, the gas turbine engine, the heat recovery steam generator and the steam turbine. Of the major systems the gas turbine engine is a fixed design offered by a manufacturer, and the steam turbine is also a fairly standard design available from a manufacturer, but it may be somewhat customized for the project. In contrast, the heat recovery steam generator (HRSG) offers many different design options, and its design is highly customized and integrated with the steam turbine. The objective of this project is to parametrically investigate the design and cost of the HRSG system, and to demonstrate the impact on the overall cost of electricity (COE) of a combined cycle power plant. There are numerous design parameters that can affect the size and complexity of the HRSG, and it is the plan for the project to identify all the important parameters and to evaluate each. For this study, the design parameter chosen for evaluation is the exhaust gas pressure drop across the HRSG. This parameter affects the performance of both the gas turbine and steam turbine and the size of the heat recovery unit. Single-pressure, two-pressure and three-pressure HRSGs are all investigated, with the tradeoffs between design point size, performance and cost evaluated for each system. A genetic algorithm is used in the design optimization process to minimize the investment cost of the HSRG. Several system level metrics are employed to evaluate a design. They are gas turbine net power, steam turbine net power, fuel consumption of the power plant, net cycle efficiency of the power plant, HRSG investment cost, total investment cost of the power plant and the operating cost measured by the cost of electricity (COE). The impacts of HRSG exhaust gas pressure drop and system complexity on these system level metrics are investigated.

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