Comparative analysis of inlet air cooling techniques integrated to cooled gas turbine plant

2015 ◽  
Vol 88 (3) ◽  
pp. 344-358 ◽  
Author(s):  
Alok Ku. Mohapatra ◽  
Sanjay
2000 ◽  
Vol 123 (2) ◽  
pp. 265-270 ◽  
Author(s):  
E. A. Khodak ◽  
G. A. Romakhova

At present high temperature, internally cooled gas turbines form the basis for the development of highly efficient plants for utility and industrial markets. Minimizing irreversibility of processes in all components of a gas turbine plant leads to greater plant efficiency. Turbine cooling, like all real processes, is an irreversible process and results in lost opportunity for producing work. Traditional tools based on the first and second laws of thermodynamics enable performance parameters of a plant to be evaluated, but they give no way of separating the losses due to cooling from the overall losses. This limitation arises from the fact that the two processes, expansion and cooling, go on simultaneously in the turbine. Part of the cooling losses are conventionally attributed to the turbine losses. This study was intended for the direct determination of lost work due to cooling. To this end, a cooled gas turbine plant has been treated as a work-producing thermodynamic system consisting of two systems that exchange heat with one another. The concepts of availability and exergy have been used in the analysis of such a system. The proposed approach is applicable to gas turbines with various types of cooling: open-air, closed-steam, and open-steam cooling. The open-air cooling technology has found the most wide application in current gas turbines. Using this type of cooling as an example, the potential of the developed method is shown. Losses and destructions of exergy in the conversion of the fuel exergy into work are illustrated by the exergy flow diagram.


2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Abdul Khaliq ◽  
M. A. Habib ◽  
Keshavendra Choudhary

This paper reports the comprehensive thermodynamic modeling of a modified combustion gas turbine plant where Brayton refrigeration cycle was employed for inlet air cooling along with evaporative after cooling. Exergetic evaluation was combined with the emission computation to ascertain the effects of operating variables like extraction pressure ratio, extracted mass rate, turbine inlet temperature (TIT), ambient relative humidity, and mass of injected water on the thermo-environmental performance of the gas turbine cycle. Investigation of the proposed gas turbine cycle revealed an exergetic output of 33%, compared to 29% for base case. Proposed modification in basic gas turbine shows a drastic reduction in cycle's exergy loss from 24% to 3% with a considerable decrease in the percentage of local irreversibility of the compressor from 5% to 3% along with a rise in combustion irreversibility from 19% to 21%. The environmental advantage of adding evaporative after cooling to gas turbine cycle along with inlet air cooling can be seen from the significant reduction of NOx from 40 g/kg of fuel to 1 × 10−9 g/kg of fuel with the moderate increase of CO concentration from 36 g/kg of fuel to 99 g/kg of fuel when the fuel–air equivalence ratio reduces from 1.0 to 0.3. Emission assessment further reveals that the increase in ambient relative humidity from 20% to 80% causes a considerable reduction in NOx concentration from 9.5 to 5.8 g/kg of fuel while showing a negligible raise in CO concentration from 4.4 to 5.0 g/kg of fuel.


Author(s):  
M. Nixdorf ◽  
A. Prelipceanu ◽  
D. Hein

The purpose of this work is to investigate the benefits of some different ambient air conditioning methods for reducing the gas turbine intake air temperature in order to enhance the gas turbine power. As a reference case the combined heat and power plant of the campus area of the Technische Universita¨t Mu¨nchen in Garching is considered, which is equipped with an Allison KH501 Cheng Cycle gas turbine. Three novel technical possibilities of ambient air cooling and power augmentation are shown in detail (desiccant dehumidification and evaporative cooling, absorption chiller unit with air cooler, evaporative cooling at increased inlet air pressure). Based on site ambient conditions and measured yearly load lines for heat and electrical power connected with actual cost functions, the potential economic savings are worked out for the different technical modifications using ambient air cooling for power augmentation of the gas turbine plant. The economic operation lines for power and heat, supplied by the modified gas turbine plant, are calculated by a cost optimization system. The results are compared based on investment costs and economic savings by the extended annual electrical and thermal power production of the modified gas turbine plant.


2014 ◽  
Vol 659 ◽  
pp. 503-508
Author(s):  
Sorin Gabriel Vernica ◽  
Aneta Hazi ◽  
Gheorghe Hazi

Increasing the energy efficiency of a gas turbine plant can be achieved by exhaust gas heat recovery in a recovery boiler. Establishing some correlations between the parameters of the boiler and of the turbine is done usually based on mathematical models. In this paper it is determined from experimental point of view, the effectiveness of a heat recovery boiler, which operates together with a gas turbine power plant. Starting from the scheme for framing the measurement devices, we have developed a measurement procedure of the experimental data. For experimental data processing is applied the effectiveness - number of transfer unit method. Based on these experimental data we establish correlations between the recovery boiler effectiveness and the gas turbine plant characteristics. The method can be adapted depending on the type of flow in the recovery boiler.


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