Evaporatively-cooled compression using a high-pressure refrigerant

2015

J. Engin. Thermophys.

In this study, analysis of the overspray fogging process, which consists of inlet fogging and wet compression processes in gas turbine cycle, is carried out with a non-equilibrium analytical modeling based on liquid droplet evaporation. The transient behaviors of droplet diameter and air temperature are examined. Special attention is paid to the effects of system parameters such as pressure ratio, water injection ratio, and initial droplet diameter on the process performances, including evaporation time of droplets, compressor outlet temperature, and compression work. Process performances are also estimated under the condition of critical water injection ratio above which complete evaporation of injected water droplets within a compressor is not possible. The analytical results indicate that the overspray fogging process has a potential of lowering compressor outlet temperature and saving significant compression work when compared to dry compression, and this technique is more effective for a higher pressure ratio and smaller size of injected water droplet.

Section: Introductionmentioning

confidence: 99%

Analytical modeling and assessment of overspray fogging process in gas turbine systems

2015

J. Engin. Thermophys.

“…Utamura [15] showed experimentally that 1% of injection ratio in wet compression leads to 8% increase in power delivery. Wet compression in gas turbines has been thoroughly investigated by many researchers as Zheng et al [16], White and Meacock [17], Kim and Perez-Blanco [18], Perez-Blanco et al [19], Bracco et al [20], Roumeliotis and Mathioudakis [21], Jonsson et al [22], Goldborough et al [23]. Kim et al [24] developed a modeling for the transient operations for the non-equilibrium wet compression process based on droplet evaporation and obtained the analytic expressions with algebraic equations as solutions.…”

Section: Introductionmentioning

confidence: 99%

Exergy Analysis of Overspray Process in Gas Turbine Systems

2012

Energies

Gas turbine power can be augmented by overspray process which consists of inlet fogging and wet compression. In this study exergy analysis of the overspray process in gas turbine system is carried out with a non-equilibrium analytical modeling based on droplet evaporation and the second law of thermodynamics. This work focuses on the effects of system parameters such as pressure ratio, water injection ratio, and initial droplet diameter on exergetical performances including irreversibility and exergy efficiency of the process. The process performances are also estimated under the condition of saturated water injection ratio above which complete evaporation of injected water droplets within a compressor is not possible. The results show that the irreversibility increases but the saturated irreversibility decreases with increasing initial droplet diameter for a specified pressure ratio.

“…Kim and Perez-Blanco [5] studied the wet-compression process employing transient heat and mass transfer analysis of evaporating droplets suspended in the air stream. Perez-Blanco et al [6] investigated for the general case of evaporatively-cooled compression with high-pressure refrigerants. The performance of gas turbine cycles with wet compression (WCG), and also of wet compression followed by recuperation of residual exhaust heat (RWCG) were investigated [7][8].…”

Section: Introductionmentioning

confidence: 99%

“…For a pressure ratio r p , the compressor discharge pressure is P 2 = r p P 1 . The polytropic efficiencies of compressor and turbine, c η and t η are defined as [5][6]:…”

mentioning

confidence: 99%

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Effects of Water and Steam Injection on Thermodynamic Performance of Gas-Turbine Systems

2011

AMM

The water and steam injection gas-turbine systems are comparatively investigated. Thermodynamic performances of the regenerative after-fogging gas-turbine (RAF) system, steam-injection gas-turbine (STIG) system, and the regenerative steam-injection gas-turbine (RSTIG) system are analyzed parametrically. Using the analytic model, the important system variables such as thermal efficiency, fuel consumption, specific power, and specific emission of CO2 gas are evaluated in terms of pressure ratio and water or steam injection ratio. The numerical results show that water or steam injection results in a notable enhancement of thermal efficiency and specific power.