Gas Turbine Intake Air Hybrid Cooling Systems and a New Approach to Their Rational Designing

Zongming Yang,Dariusz Mikielewicz,Mykola Radchenko,Roman Radchenko,Andrii Radchenko

doi:10.3390/en15041474

Abstract

Gas turbine intake air cooling (TIAC) by exhaust gas heat recovery chillers is a general trend to improve turbine fuel efficiency at increased ambient temperatures. The high efficiency absorption lithium–bromide chillers of a simple cycle are the most widely used, but they are unable to cool inlet air lower than 15 °C. A two-stage hybrid absorption–ejector chillers were developed with absorption chiller as a high temperature stage and ejector chiller as a low temperature stage to subcool air from 15 °C to 10 °C and lower. A novel trend in TIAC by two-stage air cooling in hybrid chillers has been substantiated to provide about 50% higher annual fuel saving in temperate climate as compared with absorption cooling. A new approach to reduce practically twice design cooling capacity of absorption chiller due to its rational distribution with accumulating excessive refrigeration energy at decreased thermal loads to cover the picked demands and advanced design methodology based on it was proposed. The method behind this is issued from comparing a behavior of the characteristic curves of refrigeration energy required for TIAC with its available values according to various design cooling capacities to cover daily fluctuation of thermal loads at reduced by 15 to 20% design cooling capacity and practically maximum annual fuel reduction.

Highlights

A thermodynamic efficiency of all the combustion engines falls with increasing inlet air temperature: electric power drops and specific fuel consumption grows [1,2]
The purpose of the study is to develop the innovative hybrid turbine intake air cooling (TIAC) system, and the improved methodology of its rational designing with the distribution of the overall design cooling capacity between an unstable thermal load range for ambient air precooling in the boost high temperature air cooler by ACh and a stable load range for further air subcooling to the target temperature in the low-temperature air cooler by ECh
TIAC system system designing designing consists consists of the distribution of the overall design cooling capacity between the unstable of the distribution of the overall design cooling capacity between the unstable

Summary

Introduction

A thermodynamic efficiency of all the combustion engines falls with increasing inlet air temperature: electric power drops and specific fuel consumption grows [1,2]. The combustion gas turbines (GT) are especially sensible to ambient air temperature at the inlet [3,4]. It is quite reasonable to convert the heat of exhaust gas to refrigeration for intake air cooling [5,6]. The general trend in enhancing the fuel efficiency of GT at increased ambient air temperatures is turbine intake air cooling (TIAC) by exhaust heat recovery chillers [7,8]. The exhaust heat is mostly converted to refrigeration by absorption lithium–bromide chillers [9,10] or aqua–ammonia chillers [11,12].

Objectives

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Conclusion