Reserves for increasing the effectiveness of air cooling at the gas turbine plant intake with account for seasonal climatic conditions

2016 ◽  
Vol 0 (4) ◽  
Author(s):  
Andrii M. Radchenko ◽  
Serhii A. Kantor
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.


2018 ◽  
pp. 29-36 ◽  
Author(s):  
Дмитро Вікторович Коновалов ◽  
Галина Олександрівна Кобалава

Existing technologies to improve the fuel and energy efficiency of gas turbine plants due to intercooling of the cycle air are analyzed. One of the promising ways for increasing the efficiency of such technologies is using thermogasdynamic compression in the heat recovery processes of secondary energy resources. A feature of this process is the pressure rate increase due to the instant evaporation of a finely dispersed liquid is injected into the air stream which accelerated to the speed of sound. When the pressure of the boiling liquid is increased, the power consumption for compressing the working fluid (cyclic air) is reduced, the efficiency is increased and the consumption of the fuel and energy resources of the gas turbine plant is reduced.The advantages of cooling technology with an aerothermopressor are outlined in the article. The aerothermopressor is a multifunctional jet apparatus, whose work consists in injecting water into the stream of cyclic air when it is compressed in the gas turbine plant compressor. If this apparatus is used for cooling of cycle air, it will be compensate for aerodynamic losses along the air path and it will reduce compression work in the compressor, increase the consumption of the working fluid and, as a result, increase the gas turbine plant power. The basic schemes of the aerothermopressor installation between the stages of low and high pressure compressors are considered. Theoretical thermodynamic cycles of such gas turbine plants are presented and the advantage of using a contact cooler for intercooling of the cyclic air in comparison with surface air coolers for intercooling is defined in this paper.The proposed cooling technology makes it possible using low-potential heat of secondary energy resources of gas turbine plants (heat of cyclic air), the utilization of which by traditional methods is problematic because the temperature of waste heat sources is low.The tasks are determined, the solution of which will ensure the possibility of rational organization of cooling processes in the aerothermopressor, which in turn will allow achieving optimal parameters for increasing the efficiency of the gas turbine plant and reducing the specific fuel consumption in relation to the variable climatic conditions of operation


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.


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