scholarly journals The Constant Volume Gas Turbine: A Thermodynamic Assessment

1974 ◽  
Author(s):  
M. Zockel
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Constant Pressure ◽  
Pressure Ratio ◽  
Constant Volume ◽  
Specific Power ◽  
Inlet Temperature ◽  
Turbine Efficiency ◽  
Compressor Pressure Ratio

A quasi-steady-state analysis is made of the performance of a gas-turbine working with intermittent, constant volume combustion. Variables considered include inlet temperature, compressor pressure ratio, scavenge ratio, combustion time, heat exchanger thermal ratio. Characteristics are computed over a full loading range. Computations are based on turbines having the following behavior: (a) constant turbine efficiency, (b) characteristics of a multistage axial turbine, and (c) characteristics of a single-stage radial turbine. The analysis indicates that the constant volume gas turbine has advantages in thermal efficiency, specific power and part load performance over constant pressure gas turbines operating at the same compressor pressure ratio and turbine inlet temperature. However, the addition of a heat exchanger shows less advantage when applied to a constant volume than to a constant pressure engine.

Genetic Optimization of Steam Injected Gas Turbine Power Plants

2002 ◽  
Author(s):  
Ibrahim Sinan Akmandor ◽  
O¨zhan O¨ksu¨z ◽  
Sec¸kin Go¨kaltun ◽  
Melih Han Bilgin
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Power Plants ◽  
Pressure Ratio ◽  
Steam Injection ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Compressor Pressure Ratio

A new methodology is developed to find the optimal steam injection levels in simple and combined cycle gas turbine power plants. When steam injection process is being applied to simple cycle gas turbines, it is shown to offer many benefits, including increased power output and efficiency as well as reduced exhaust emissions. For combined cycle power plants, steam injection in the gas turbine, significantly decreases the amount of flow and energy through the steam turbine and the overall power output of the combined cycle is decreased. This study focuses on finding the maximum power output and efficiency of steam injected simple and combined cycle gas turbines. For that purpose, the thermodynamic cycle analysis and a genetic algorithm are linked within an automated design loop. The multi-parameter objective function is either based on the power output or on the overall thermal efficiency. NOx levels have also been taken into account in a third objective function denoted as steam injection effectiveness. The calculations are done for a wide range of parameters such as compressor pressure ratio, turbine inlet temperature, air and steam mass flow rates. Firstly, 6 widely used simple and combined cycle power plants performance are used as test cases for thermodynamic cycle validation. Secondly, gas turbine main parameters are modified to yield the maximum generator power and thermal efficiency. Finally, the effects of uniform crossover, creep mutation, different random number seeds, population size and the number of children per pair of parents on the performance of the genetic algorithm are studied. Parametric analyses show that application of high turbine inlet temperature, high air mass flow rate and no steam injection lead to high power and high combined cycle thermal efficiency. On the contrary, when NOx reduction is desired, steam injection is necessary. For simple cycle, almost full amount of steam injection is required to increase power and efficiency as well as to reduce NOx. Moreover, it is found that the compressor pressure ratio for high power output is significantly lower than the compressor pressure ratio that drives the high thermal efficiency.

Performance of Integrated Combined and Cogeneration Cycles Using Latest Gas Turbines

2004 ◽  
Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Utilization Efficiency ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Specific Work ◽  
Fuel Utilization ◽  
Compressor Pressure Ratio ◽  
Cogeneration Cycle

The paper deals with the thermodynamic performance of combined and cogeneration cycles using the state of the art gas turbines. A configuration has been conceptualized using the latest gas turbine MS9001H that uses steam to cool the hot gas path components. In order to study the effect of cooling means, the same gas turbine is subjected to transpiration air cooling. Using the above mentioned conceptualized topping cycle, the bottoming cycle selected consists of a two-pressure reheat heat recovery steam generator (HRSG) with reheat having two options. First option is the integrated system (IS), which is a combined/cogeneration cycle, and the other is called the normal cogeneration cycle (NC). Both of these cycles are subjected to steam and transpiration air-cooling. The cycle performance is predicted based on parameteric study which has been carried out by modeling the various elements of cycle such as gas, compressor combustor, cooed gas turbine, HRSG steam turbine, condenser, etc. The performance is predicted for parameters such as fuel utilization efficiency (ηf), power-to-heat-ratio (PHR), coolant flow requirements, plant specific work, etc. as a function of independent parameters such as compressor pressure ratio (rpc) and turbine inlet temperature (TIT), etc. The results predicted will be helpful for designers to select the optimum compressor pressure ratio and TIT to achieve the target fuel utilization efficiency, and PHR at the target plant specific work.

Thermodynamic Evaluation of Advanced Combined Cycle Using Latest Gas Turbine

2003 ◽  
Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Specific Work ◽  
Thermodynamic Evaluation ◽  
Compressor Pressure Ratio ◽  
Steam Cooling ◽  
Plant Efficiency

The present work deals with the thermodynamic evaluation of combined cycle with re-heat in gas turbine using the latest gas turbines namely ABB GT26 gas turbine (advanced) in which reheat is used and the blade cooling is done by air bled from compressor. The same turbine is subjected to closed loop steam cooling. Parametric study has been performed on plant efficiency and specific work for various independent parameters such as turbine inlet temperature, compressor pressure ratio, reheating pressure ratio, reheater inlet temperature, blade temperature, etc.. It has been observed that due to higher compressor pressure ratio involved in reheat gas turbine combined cycle and higher temperature of exhaust, the plant efficiency and specific work are higher with the advanced reheat gas/steam combined cycle over the simple combined cycle. Steam cooling offers better performance over aircooling.

Thermodynamic Performance of Wet Compression and Regenerative (WCR) Gas Turbine

2003 ◽  
Author(s):  
Qun Zheng ◽  
Minghong Li ◽  
Yufeng Sun
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Regenerative Process ◽  
Specific Power ◽  
Heat Recovery Steam Generator ◽  
Thermodynamic Performance ◽  
Wet Compression ◽  
Steam Heat

Thermodynamic performance of wet compression and regenerative (WCR) gas turbine are investigated in this paper. The regenerative process can be achieved by a gas/air (and steam) heat exchanger, a regenerator, or by a heat recovery steam generator and then the steam injected into the gas turbine. Several schemes of the above wet compression and regenerative cycles are computed and analyzed. The calculated results indicate that not only a significant specific power can be obtained, but also is the WCR gas turbine an economic competitive option of efficient gas turbines.

Impact of Inlet Fogging on the Performance of Steam Injected Cooled Gas Turbine Based Combined Cycle Power Plant

2017 ◽  
Author(s):  
Anoop Kumar Shukla ◽  
Onkar Singh
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Film Cooling ◽  
Pressure Ratio ◽  
Steam Injection ◽  
Combined Cycle ◽  
Specific Power ◽  
Temperature Cycle ◽  
Inlet Temperature ◽  
Combined Cycle Power Plant

Gas/steam combined cycle power plants are extensively used for power generation across the world. Today’s power plant operators are persistently requesting enhancement in performance. As a result, the rigour of thermodynamic design and optimization has grown tremendously. To enhance the gas turbine thermal efficiency and specific power output, the research and development work has centered on improving firing temperature, cycle pressure ratio, adopting improved component design, cooling and combustion technologies, and advanced materials and employing integrated system (e.g. combined cycles, intercooling, recuperation, reheat, chemical recuperation). In this paper a study is conducted for combining three systems namely inlet fogging, steam injection in combustor, and film cooling of gas turbine blade for performance enhancement of gas/steam combined cycle power plant. The evaluation of the integrated effect of inlet fogging, steam injection and film cooling on the gas turbine cycle performance is undertaken here. Study involves thermodynamic modeling of gas/steam combined cycle system based on the first law of thermodynamics. The results obtained based on modeling have been presented and analyzed through graphical depiction of variations in efficiency, specific work output, cycle pressure ratio, inlet air temperature & density variation, turbine inlet temperature, specific fuel consumption etc.

Parameter Optimization on Combined Gas Turbine-Fuel Cell Power Plants

2005 ◽  
Vol 2 (4) ◽  
pp. 268-273 ◽  
Author(s):  
Rainer Kurz
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Power Plants ◽  
Pressure Ratio ◽  
Design Parameters ◽  
Turbine Efficiency ◽  
Compressor Pressure Ratio ◽  
Turbine Design ◽  
Cycle Efficiency ◽  
Compressor Efficiency

A thermodynamic model for a gas turbine-fuel cell hybrid is created and described in the paper. The effects of gas turbine design parameters such as compressor pressure ratio, compressor efficiency, turbine efficiency, and mass flow are considered. The model allows to simulate the effects of fuel cell design parameters such as operating temperature, pressure, fuel utilization, and current density on the cycle efficiency. This paper discusses, based on a parametric study, optimum design parameters for a hybrid gas turbine. Because it is desirable to use existing gas turbine designs for the hybrids, the requirements for this hybridization are considered. Based on performance data for a typical 1600hp industrial single shaft gas turbine, a model to predict the off-design performance is developed. In the paper, two complementary studies are performed: The first study attempts to determine the range of cycle parameters that will lead to a reasonable cycle efficiency. Next, an existing gas turbine, that fits into the previously established range of parameters, will be studied in more detail. Conclusions from this paper include the feasibility of using existing gas turbine designs for the proposed cycle.

Off-Design Performance Investigation of a Low Calorific Value Gas Fired Generic-Type Single-Shaft Gas Turbine

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Raik C. Orbay ◽  
Magnus Genrup ◽  
Pontus Eriksson ◽  
Jens Klingmann
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Calorific Value ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Flammability Limits ◽  
Generic Type ◽  
Wobbe Index ◽  
The Impact

When low calorific value gases are fired, the performance and stability of gas turbines may deteriorate due to a large amount of inertballast and changes in working fluid properties. Since it is rather rare to have custom-built gas turbines for low lower heating value (LHV) operation, the engine will be forced to operate outside its design envelope. This, in turn, poses limitations to usable fuel choices. Typical restraints are decrease in Wobbe index and surge and flutter margins for turbomachinery. In this study, an advanced performance deck has been used to quantify the impact of firing low-LHV gases in a generic-type recuperated as well as unrecuperated gas turbine. A single-shaft gas turbine characterized by a compressor and an expander map is considered. Emphasis has been put on predicting the off-design behavior. The combustor is discussed and related to previous experiments that include investigation of flammability limits, Wobbe index, flame position, etc. The computations show that at constant turbine inlet temperature, the shaft power and the pressure ratio will increase; however, the surge margin will decrease. Possible design changes in the component level are also discussed. Aerodynamic issues (and necessary modifications) that can pose severe limitations on the gas turbine compressor and turbine sections are discussed. Typical methods for axial turbine capacity adjustment are presented and discussed.

Thermodynamic Evaluation of Gas Turbine Cogeneration Cycles: Part I—Heat Balance Method Analysis

1987 ◽  
Vol 109 (1) ◽  
pp. 1-7 ◽  
Author(s):  
I. G. Rice
Keyword(s):  
Gas Turbine ◽  
Heat Balance ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Pressure Ratio ◽  
Turbine Rotor ◽  
Balance Method ◽  
Inlet Temperature ◽  
Thermodynamic Evaluation ◽  
Exhaust Temperature

This paper presents a heat balance method of evaluating various open-cycle gas turbines and heat recovery systems based on the first law of thermodynamics. A useful graphic solution is presented that can be readily applied to various gas turbine cogeneration configurations. An analysis of seven commercially available gas turbines is made showing the effect of pressure ratio, exhaust temperature, intercooling, regeneration, and turbine rotor inlet temperature in regard to power output, heat recovery, and overall cycle efficiency. The method presented can be readily programmed in a computer, for any given gaseous or liquid fuel, to yield accurate evaluations. An X–Y plotter can be utilized to present the results.

Development of the Transpiration Air-Cooled Turbine for High-Temperature Dirty Gas Streams

1983 ◽  
Vol 105 (4) ◽  
pp. 821-825 ◽  
Author(s):  
J. Wolf ◽  
S. Moskowitz
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Specific Power ◽  
Skin Permeability ◽  
Air Cooling ◽  
Initial Exposure ◽  
Flow Capacity

Studies of combined cycle electic power plants have shown that increasing the firing temperature and pressure ratio of the gas turbine can substantially improve the specific power output of the gas turbine as well as the combined cycle plant efficiency. Clearly this is a direction in which we can proceed to conserve the world’s dwindling petroleum fuel supplies. Furthermore, tomorrow’s gas turbines must do more than operate at higher temperature; they will likely face an aggressive hot gas stream created by the combustion of heavier oils or coal-derived liquid or gaseous fuels. Extensive tests have been performed on two rotating turbine rigs, each with a transpiration air cooled turbine operating in the 2600 to 3000°F (1427 to 1649°C) temperature range at increasing levels of gas stream particulates and alkali metal salts to simulate operation on coal-derived fuel. Transpiration air cooling was shown to be effective in maintaining acceptable metal temperatures, and there was no evidence of corrosion, erosion, or deposition. The rate of transpiration skin cooling flow capacity exhibited a minor loss in the initial exposure to the particulate laden gas stream of less than 100 hours, but the flow reduction was commensurate with that produced by normal oxidation of the skin material at the operating temperatures of 1350°F (732°C). The data on skin permeability loss from both cascade and engine tests compared favorably with laboratory furnace oxidation skin specimens. To date, over 10,000 hr of furnace exposure has been conducted. Extrapolation of the data to 50,000 hr indicates the flow capacity loss would produce an acceptable 50°F (10°C) increase in skin operating temperature.

scholarly journals 100s and 1000s Mw Open and Semi-Closed Cycle Gas Turbines for Base and Peak Operation

1974 ◽  
Author(s):  
V. V. Uvarov ◽  
V. S. Beknev ◽  
E. A. Manushin
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Simple Cycle ◽  
Inlet Temperature ◽  
Closed Cycle ◽  
Turbine Inlet Temperature ◽  
Unit Capacity ◽  
Temperature And Pressure ◽  
Different Levels

There are two different approaches to develop the gas turbines for power. One can get some megawatts by simple cycle or by more complex cycle units. Both units require very different levels of turbine inlet temperature and pressure ratio for the same unit capacity. Both approaches are discussed. These two approaches lead to different size and efficiencies of gas turbine units for power. Some features of the designing problems of such units are discussed.

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