Evaluation of Interstage Water Injection Effect on Compressor and Engine Performance

2004 ◽  
Vol 128 (4) ◽  
pp. 849-856 ◽  
Author(s):  
I. Roumeliotis ◽  
K. Mathioudakis
Keyword(s):  
Performance Enhancement ◽  
Water Injection ◽  
Engine Performance ◽  
Performance Model ◽  
Injection Point ◽  
Effect Of Water ◽  
Compression Model ◽  
Compressor Inlet ◽  
Wet Compression ◽  
Injection Effect

The present paper examines the effect of water injection at the compressor inlet or between stages, on its operation. A wet compression model coupled with an engine performance model is used. The wet compression model produces the compressor performance map when water is present and consists of a one-dimensional stage stacking model, coupled with a droplet evaporation model. The effect of water injection on overall performance and individual stage operation is examined. The map-generation procedure is embedded in an engine performance model and a study of water injection effect on overall engine performance is undertaken. The possibility to evaluate the effect on various parameters such as power, thermal efficiency, surge margin, as well as the progression of droplets through the stages is demonstrated. The results indicate that water injection causes significant stage rematching, leading the compressor toward stall and that the performance enhancement is greater as the injection point moves towards compressor inlet.

Evaluation of Interstage Water Injection Effect on Compressor and Engine Performance

2005 ◽  
Author(s):  
I. Roumeliotis ◽  
K. Mathioudakis
Keyword(s):  
Performance Enhancement ◽  
Water Injection ◽  
Engine Performance ◽  
Performance Model ◽  
Injection Point ◽  
Effect Of Water ◽  
Compression Model ◽  
Compressor Inlet ◽  
Wet Compression ◽  
Injection Effect

The present paper examines the effect of water injection at the compressor inlet or between stages, on its operation. A wet compression model coupled with an engine performance model is used. The wet compression model produces the compressor performance map when water is present and consists of a one dimensional stage stacking model, coupled with a droplet evaporation model. The effect of water injection on overall performance and individual stage operation is examined. The map generation procedure is embedded in an engine performance model and a study of water injection effect on overall engine performance is undertaken. The possibility to evaluate the effect on various parameters such as power, thermal efficiency, surge margin, as well as the progression of droplets through the stages is demonstrated. The results indicate that water injection causes significant stage rematching, leading the compressor towards stall and that the performance enhancement is greater as the injection point moves towards compressor inlet.

scholarly journals Energy and Exergy Analysis of a Simple Gas Turbine Cycle with Wet Compression

2018 ◽  
Vol 8 (1) ◽  
pp. 30 ◽  
Author(s):  
E. H. Betelmal ◽  
S. A. Farhat
Keyword(s):  
Gas Turbine ◽  
Water Injection ◽  
Analytical Formula ◽  
Heat Rate ◽  
Performance Model ◽  
Exergy Destruction ◽  
Isentropic Compression ◽  
Turbine Efficiency ◽  
Wet Compression ◽  
Gas Turbine Cycle

A thermodynamic model of the wet compressor in a simple gas turbine cycle was investigated in this paper. A suitable quantity of water was injected into the compressor-stages where it evaporated. Subsequently, the steam and air were heated in the combustion chamber and expanded in the turbine. The wet compressor (WC) has become a reliable way to reduce gas emissions and increase gas turbine efficiency. In this study, the operational data of the simple gas turbine and the maximum amount of water that can be injected into the compressor were assessed, as well as a comparison between the dry compression, the wet compression and the isentropic compression. The performance variation due to water spray in the compressor and the effect of varying ambient temperature on the performance of gas turbine (thermal efficiency, power) was investigated, and the results are compared to the results of the same cycle with a dry compressor. The analytical formula of exergy destruction and results show that exergy destruction increases with water injection. The programming of the performance model for the gas turbine was developed utilizing the software IPSEpro. The results of the gas turbine with a wet compressor demonstrates a 12% reduction in the compressor exit temperature up to isentropic temperature. The compressor work decreased by 11% when using a wet compressor, this lead to an improvement in power output and efficiency However, the wet compressor increases the specific fuel consumption and heat rate of the gas turbine. There are limitations in the amount of steam that can be injected, 0.4 kg/s of water was the optimum amount injected into the compressor.

An Investigation of the Use of Wet Compression in Industrial Centrifugal Compressors

2006 ◽  
Author(s):  
Ahmed Abdelwahab
Keyword(s):  
Pressure Ratio ◽  
Water Injection ◽  
Centrifugal Compressors ◽  
Power Requirement ◽  
Operating Range ◽  
Multi Stage ◽  
Direct Water Injection ◽  
Compressor Inlet ◽  
Wet Compression ◽  
Compressor Power

Industrial centrifugal compressors generally comprise a number of low pressure ratio intercooled stages. This is done primarily for the purpose of reducing the compressor power requirements and improving the operating range of the multi-stage compressor. In recent years, however, rapid increases in the per-kilowatt-hour prices both domestically and worldwide has led to renewed research efforts to further reduce the power requirements of this type of compression equipment. Several attempts have been made to use direct water injection as a means to overspray the compressor inlet to further reduce its power requirement. This paper presents an investigation into the use of this technology in industrial centrifugal compressors. A simple numerical method is presented for the computation of wet compression processes. The method is based on both droplet evaporation and compressor mean-line calculations. An assessment, based on the developed model, of the effectiveness of evaporative processes in reducing the compressor power consumption per stage is presented. The impacts on stage efficiency and operating range are also presented.

scholarly journals Optimal Control of a Compound Rotorcraft for Engine Performance Enhancement

2020 ◽  
Author(s):  
Calum Scullion ◽  
Stavros Vouros ◽  
Ioannis Goulos ◽  
Devaiah Nalianda ◽  
Vassilios Pachidis
Keyword(s):  
Optimal Control ◽  
Flight Control ◽  
Performance Enhancement ◽  
Engine Performance ◽  
Performance Model ◽  
Flight Speed ◽  
Gaseous Emissions ◽  
Fuel Burn ◽  
Redundant Control ◽  
The Impact

Abstract Demands for rotorcraft with increased flight speed, improved operational performance and reduced environmental impact have led to a drive in research and development of alternative concepts. Compound rotorcraft overcome the flight speed limitations of conventional helicopters with additional lifting and propulsive components. Further to operational benefits, these augmentations provide additional flight control parameters, resulting in control redundancy. This work aims to investigate the impact of optimal control strategies for a generic coaxial compound rotorcraft, equipped with turboshaft engines, targeting the minimization of mission fuel burn and gaseous emissions. The direct redundant controls considered are: (a) main rotor speed, (b) propeller speed, and (c), fuselage pitch attitude. A simulation tool for coaxial compound rotorcraft analysis has been developed and coupled to a zero-dimensional engine performance model and a stirred-reactor combustor model. Firstly, experimental and flight test data were used to provide extensive validation of the developed models. A parametric analysis was then carried out to gain insight into the effect of the redundant controls. This was followed by the derivation of a generalized set of optimal redundant control allocations using a surrogate-assisted genetic algorithm. Application of the optimal redundant control allocations during realistic operational scenarios has demonstrated reductions in fuel burn and NOX of up to 6.93% and 8.74% respectively. The developed method constitutes a rigorous approach to guide the design of control systems for future advanced rotorcraft.

Numerical Through Flow Simulation of a Gas Turbine Engine With Wet Compression

2012 ◽  
Author(s):  
Lanxin Sun ◽  
Qun Zheng ◽  
Yijin Li ◽  
Mingcong Luo ◽  
Jie Wang ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Droplet Diameter ◽  
Engine Performance ◽  
Flow Simulation ◽  
Turbine Engine ◽  
Turbojet Engine ◽  
Characteristic Map ◽  
Compressor Inlet ◽  
Mass Flowrate ◽  
Wet Compression

In this paper, a thorough flow simulation of a small turbojet engine has been carried out to predict the engine performance as a result of water injected at the compressor inlet. Wet compression will not only change compressor performance characteristic map, but also has effects on both the combustor and the turbine sections. The match between the turbojet engine components, that is the compressor, combustor and turbine, will shift to a new operating point. In this paper, we present a steady-state numerical simulation of the entire gas turbine with wet compression in order to evaluate the effects on the gas turbine performance. Compared with the dry case, the results of wet cases show increased values of compressor compression ratios, turbine expansion ratios, intake mass flowrates and engine thrusts including decreased amount of specific fuel consumption. The wet compression reduces NOx production in the combustor, which is also simulated and results presented. The study also indicates that the water mass flowrate and droplet diameter are key factors impacting the engine performance.

scholarly journals Optimal Control of a Compound Rotorcraft for Engine Performance Enhancement

2020 ◽  
Author(s):  
Calum Scullion ◽  
Stavros Vouros ◽  
Ioannis Goulos ◽  
Devaiah Nalianda ◽  
Vassilios Pachidis
Keyword(s):  
Optimal Control ◽  
Flight Control ◽  
Performance Enhancement ◽  
Engine Performance ◽  
Performance Model ◽  
Flight Speed ◽  
Gaseous Emissions ◽  
Fuel Burn ◽  
Redundant Control ◽  
The Impact

Abstract Demands for rotorcraft with increased flight speed, improved operational performance and reduced environmental impact have led to a drive in research and development of alternative concepts. Compound rotorcraft overcome the flight speed limitations of conventional helicopters with additional lifting and propulsive components. Further to operational benefits, these augmentations provide additional flight control parameters, resulting in control redundancy. This work aims to investigate the impact of optimal control strategies for a generic coaxial compound rotorcraft, equipped with turboshaft engines, targeting the minimization of mission fuel burn and gaseous emissions. The direct redundant controls considered are: (a) main rotor speed, (b) propeller speed, and (c), fuselage pitch attitude. A simulation tool for coaxial compound rotorcraft analysis has been developed and coupled to a zero-dimensional engine performance model and a stirred-reactor combustor model. Firstly, experimental and flight test data were used to provide extensive validation of the developed models. A parametric analysis was then carried out to gain insight into the effect of the redundant controls. This was followed by the derivation of a generalized set of optimal redundant control allocations using a surrogate-assisted genetic algorithm. Application of the optimal redundant control allocations during realistic operational scenarios has demonstrated reductions in fuel burn and NOx of up to 6.93% and 8.74% respectively. The developed method constitutes a rigorous approach to guide the design of control systems for future advanced rotorcraft.

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