Gas Turbine Intake Air Research Articles

Effect of gas turbine intake air temperature regulating heat exchanger on combined cycle performance based on three-dimensional deformed tube

Effect of gas turbine intake air temperature regulating heat exchanger on combined cycle performance based on three-dimensional deformed tube

A comparative and critical review on gas turbine intake air pre-cooling strategies

A comparative and critical review on gas turbine intake air pre-cooling strategies

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

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.

Simulation of innovative hybridizing M-cycle cooler and absorption-refrigeration for pre-cooling of gas turbine intake air: Including a case study for Siemens SGT-750 gas turbine

Higher compressor intake-air temperature not only significantly reduces the performance of the gas turbine (GT), but also increases the NOx emissions. Absorption (AB) refrigeration, which is powered by heat, is a promising option for cooling GT intake air. M-cycle technology is a unique water-based indirect evaporative cooler (IEC) providing sub wet-bulb temperature. In novel hybrid pre-cooler, the air is cooled down to near dew-point temperature by the M-cycle first and then further cooled by the AB. Both AB and M-cycle coolers consume very little electricity and the main required sources (heat for AB refrigeration and water for the M-cycle IEC) are provided by waste heat from GT and condensed water from AB meaning almost zero-energy pre-cooler for GT intake air. The dependency of the intake mass flow and GT power output on the intake air temperature is first identified and correlated using experimental data provided by Siemens company, and then the required physical/mathematical modelling is presented and developed using Engineering Equation Solver. Finally, the GT performance is comprehensively discussed for a wide range of climate conditions when the AB and M-cycle work solely or jointly as a GT intake air pre-cooler. The hybrid pre-cooler was found to be a cost-effective way to boost the GT power output by 29%, however, this enhancement for GT using AB refrigeration and M-cycle IEC was around 17% and 15% in average respectively.

Using Heat Pumps to Improve the Efficiency of Combined-Cycle Gas Turbines

This paper studies the integration of heat pump units (HPUs) to enhance the thermal efficiency of a combined heat and power plant (CHPP). Different solutions of integrate the HPUs in a combined-cycle gas turbine (CCGT) plant, the CCGT-450, are analyzed based on simulations developed on “United Cycle” computer-aided design (CAD) system. The HPUs are used to explore low-potential heat sources (LPHSs) and heat make-up and return network water. The use of HPUs to regulate the gas turbine (GT) intake air temperature during the summer operation and the possibility of using a HPU to heat the GT intake air and replace anti-icing system (AIS), over the winter at high humidity conditions were also analyzed. The best solution was obtained for the winter operation mode replacing the AIS by a HPU. The simulation results indicated that this scheme can reduce the underproduction of electricity generation by the CCGT unit up to 14.87% and enhance the overall efficiency from 40.00% to 44.82%. Using a HPU with a 5.04 MW capacity can save $309,640 per each MW per quarter.

Gas turbine intake air hybrid cooling systems and their rational designing

The general trend to improve the fuel efficiency of gas turbines (GT) at increased ambient temperatures is turbine intake air cooling (TIAC) by exhaust heat recovery chillers The high efficiency absorption lithium-bromide chillers (ACh) of a simple cycle are the most widely used, but they are not able to cool intake air lower than 15°C because of a chilled water temperature of about 7°C. A two-stage hybrid absorption-ejector chillers (AECh) were developed with ejector chiller as a low temperature stage to provide deep air cooling to 10°C and lower. A novel trend in TIAC by two-stage air cooling in chillers of hybrid type has been proposed to provide about 50% higher annual fuel saving in temperate climatic conditions as compared with ACh cooling. The advanced methodology to design and rational distribute the cooling capacity of TIAC systems that provides a closed to maximum annual fuel reduction without oversizing was developed.

Gas turbine intake air cooling systems of combined type and their optimum designing

Turbine intake air cooling (TIAC) by absorption lithium-bromide chillers (ACh) utilizing the exhaust heat is considered as the most effective fuel saving technology for temperate climatic conditions. But the cooling potential of TIAC systems based on ACh of a simple cycle is limited by a comparatively increased chilled water temperature of about 7°C excluding cooling intake air lower than 15°C. The application of a refrigerant as a coolant enables deeper cooling intake air to 10°C and lower. The application of two-stage hybrid absorption-ejector chillers (AECh) with a refrigerant ejector chiller (ECh) as a low temperature stage makes it possible to increase the annual fuel saving approximately twice in temperate climate due to deeper cooling air as compared with ACh. Furthermore, this effect can be achieved with the sizes of TIAC system reduced by about 20 % due to determining the rational refrigeration capacity of AECh providing practically maximum annual fuel saving increment and the use of the current excessive refrigeration capacities to cover peaked loads.

Spray Characteristics and Cooling Effect of Water Spray for Gas Turbine Intake Air

Spray Characteristics and Cooling Effect of Water Spray for Gas Turbine Intake Air

A fuel saving estimation of gas turbine intake air cooling for climatic conditions in various regions of Libya

A fuel saving estimation of gas turbine intake air cooling for climatic conditions in various regions of Libya

Inlet Air Cooling Methods for Gas Turbine Based Power Plants

Background: Power generation from gas turbines is penalized by a substantial power output loss with increased ambient temperature. By cooling down the gas turbine intake air, the power output penalty can be mitigated. Method of Approach: The purpose of this paper is to review the state of the art in applications for reducing the gas turbine intake air temperature and examine the merits from integration of the different air-cooling methods in gas-turbine-based power plants. Three different intake air-cooling, methods (evaporative cooling, refrigeration cooling, and evaporative cooling of precompressed air) have been applied in two combined cycle power plants and two gas turbine plants. The calculations were performed on a yearly basis of operation, taking into account the time-varying climatic conditions. The economics from integration of the different cooling systems were calculated and compared. Results: The results have demonstrated that the highest incremental electricity generation is realized by absorption intake air-cooling. In terms of the economic performance of the investment, the evaporative cooler has the lowest total cost of incremental electricity generation and the lowest payback period (PB). Concerning the cooling method of pre-compressed air, the results show a significant gain in capacity, but the total cost of incremental electricity generation in this case is the highest. Conclusions: Because of the much higher capacity gain by an absorption chiller system, the evaporative cooler and the absorption chiller system may both be selected for boosting the performance of gas-turbine-based power plants, depending on the prevailing requirements of the plant operator.

International standards: filters for buildings and gas turbines

The development of standards for the filtration industry continues to take prominence worldwide. In the first of a two part feature, Paolo Tronville and Richard Rivers examine the development of standards for filters used in general building ventilation, as well as for gas turbine intake air cleaning.