The influences of turbine blade mean temperature and component efficiencies on coolant optimization in the gas turbine

Author(s):  
B W Martin ◽  
A Brown ◽  
M Finnis

This paper continues the computational invcstigalion of optimum performance of a gas turbine configuration incorporating a gas generator, previously reported by the authors. Even for contemporary pressure ratios not previously considered, there appears to be no advantage in prebleeding the coolant air, and within the range considered, as previously found, the amount of coolant preheating has only a secondary effect on maximum engine efficiency. This is also true of the influence of allowable mean blade temperature on maximum engine efficiency, but both factors do have a pronounced effect on the optimum coolant and where maximum cycle efficiency is primarily determined by compressor pressure ratio and component isen-tropic efficiencies. The specific work output is confirmed under optimum conditions to be an almost linear function of the compressor turbine inlet temperature.

Author(s):  
Meherwan P. Boyce ◽  
Cyrus B. Meher-Homji ◽  
A. N. Lakshminarasimha

A wide variety of gas turbine based cycles exist in the market today with several technologies being promoted by individual Original Equipment Manufacturers. This paper is focused on providing users with a conceptual framework within which to view these cycles and choose suitable options for their needs. A basic parametric analysis is provided to show the interdependency of Turbine Inlet Temperature (TIT) and Pressure Ratio on cycle efficiency and specific work.


Author(s):  
A. F. Carter

During a study of possible gas turbine cycles for a 2000-hp unit for tank propulsion, it has been established that the level of achievable specific fuel consumption (sfc) is principally determined by the combustor inlet temperature. If a regenerative cycle is selected, a particular value of combustor inlet temperature (and hence sfc) can be produced by an extremely large number of combinations of compressor pressure ratio, turbine inlet temperature, and heat exchanger effectiveness. This paper outlines the overall design considerations which led to the selection of a relatively low pressure ratio engine in which the turbine inlet temperature was sufficiently low that blade cooling was not necessary.


2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2641-2651 ◽  
Author(s):  
Moein Shamoushaki ◽  
Mehdi Ehyaei

In this paper, exergy, exergoeconomic, and exergoenvironmental analysis of a gas turbine cycle and its optimization has been carried out by MOPSO algorithm. Three objective functions, namely, total cost rate, exergy efficiency of cycle, and CO2 emission rate have been considered. The design variables considered are: compressor pressure ratio, combustion chamber inlet temperature, gas turbine inlet temperature, compressor, and gas turbine isentropic efficiency. The impact of change in gas turbine inlet temperature and compressor pressure ratio on CO2 emission rate as well as impact of changes in gas turbine inlet temperature on exergy efficiency of the cycle has been investigated in different compressor pressure ratios. The results showed that with increase in compressor pressure ratio and gas turbine inlet temperature, CO2 emission rate decreases, that is this reduction is carried out with a steeper slope at lower pressure compressor ratio and gas turbine inlet temperature. The results showed that exergy efficiency of the cycle increases with increase in gas turbine inlet temperature and compressor pressure ratio. The sensitivity analysis of fuel cost changes was performed on objective functions. The results showed that at higher exergy efficiencies total cost rate is greater, and sensitivity of fuel cost optimum solutions is greater than Pareto curve with lower total cost rate. Also, the results showed that sensitivity of changes in fuel cost rate per unit of energy on total cost rate is greater than the rate of CO2 emission.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Mousafarash

A combined cooling, heating, and power (CCHP) system which produces electricity, heating, and cooling is modeled and analyzed. This system is comprised of a gas turbine, a heat recovery steam generator, and a double-effect absorption chiller. Exergy analysis is conducted to address the magnitude and the location of irreversibilities. In order to enhance understanding, a comprehensive parametric study is performed to see the effect of some major design parameters on the system performance. These design parameters are compressor pressure ratio, gas turbine inlet temperature, gas turbine isentropic efficiency, compressor isentropic efficiency, and temperature of absorption chiller generator inlet. The results show that exergy efficiency of the CCHP system is higher than the power generation system and the cogeneration system. In addition, the results indicate that when waste heat is utilized in the heat recovery steam generator, the greenhouse gasses are reduced when the fixed power output is generated. According to the parametric study results, an increase in compressor pressure ratio shows that the network output first increases and then decreases. Furthermore, an increase in gas turbine inlet temperature increases the system exergy efficiency, decreasing the total exergy destruction rate consequently.


Author(s):  
R. Yadav ◽  
Pradeep Kumar ◽  
Samir Saraswati

This paper presents a comparative study of first and second law thermodynamic analysis of combined and recuperated and non-recuperated steam injected gas turbine cycles. The analysis has been carried out by developing a computer code, which is based on the modeling of various elements of these cycles. The gas turbine chosen for the analysis is MS9001H developed recently by GE and the steam cycle is having a triple-pressure heat recovery steam generator with reheat. It has been observed that the combined cycle is superior to the steam injected cycle, however, the gap narrows down with increasing compressor pressure ratio and high value of turbine inlet temperature. The detailed exergy losses have been presented in various elements of combined and steam injected cycles.


Author(s):  
A. F. Massardo ◽  
M. Scialò

The thermoeconomic analysis of gas turbine based cycles is presented and discussed in this paper. The thermoeconomic analysis has been performed using the ThermoEconomic Modular Program (TEMP V.5.0) developed by the Authors (Agazzani and Massardo, 1997). The modular structure of the code allows the thermoeconomic analysis for different scenarios (turbine inlet temperature, pressure ratio, fuel cost, installation costs, operating hours per year, etc.) of a large number of advanced gas turbine cycles to be obtained in a fast and reliable way. The simple cycle configuration results have been used to assess the cost functions and coefficient values. The results obtained for advanced gas turbine based cycles (intercooled, re-heated, regenerated and their combinations) are presented using new and useful representations: cost vs. efficiency, cost vs. specific work, and cost vs. pressure ratio. The results, including productive diagram configurations, are discussed in detail and compared to one another.


Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad

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.


Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad

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.


Author(s):  
M. Nakhamkin ◽  
E. C. Swensen ◽  
Arthur Cohn

This paper describes the first phase of an intended project to develop a reheat combustor-power turbine (RCPT) package which when added to an aircraft derivative gas generator would produce a commercially attractive reheat gas turbine for combined cycle and cogeneration applications. This first phase includes the identification of gas generators and establishes the relative merits of the RCPT package at various inlet temperatures based upon evaluated benefits. Our calculations show that in combined cycle application with the RCPT at an easily feasible power turbine inlet temperature of 1700°F, the steam flow increases by approximately 2.5 times, the combined cycle power by about 30%, and the combined cycle efficiency by about 5% compared to an unfired aeroderivative combined cycle. Compared to the duct fired combined cycle with the same power output, the efficiency increases by approximately 7.5%, leading to a lower cost of electricity of about 10 per cent for the economic assumptions of the study.


Sign in / Sign up

Export Citation Format

Share Document