Enhancement of twin-shaft gas turbine performance by water injection

Dissertant

Muhammad, Abd al-Sattar Jawad

Thesis advisor

Ahmad, Sabah Tariq
al-Duri, Muthanna Khalis

University

University of Technology

Faculty

-

Department

Department of Electromechanical Engineering

University Country

Iraq

Degree

Ph.D.

Degree Date

2010

English Abstract

Intake air mass flow during hot and dry climates.

Cooling the inlet air should increase the density of the incoming air and hence, boost the power output and cycle efficiency.

This work provides the results of an extensive experimental and theoretical study conducted on the inlet air cooling utilizing the inlet fogging technique that introducing water as a mist of tiny droplets sprayed into the incoming air flow.

The experimental study focuses on the determination of the feasible effective location of the spray nozzle with respect to the gas turbine inlet matrix, and its influence on a two-shaft T200D micro-gas turbine cycle parameters.

Results indicated that the effective entry length for the system used in the study was 1m.

The degradation in power output was evaluated to be 1.8 % for each 1oC rise in the ambient temperature.

Water addition aids in power augmentation when 4 l / h of water is sprayed into a 45oC air drought, an average drop in air temperature of 37.2 % was recorded accompanied with an increase in air flow of about 9.2 %.

A 23.6 % boost in power output at 450C ambient air was observed when the air is brought to saturation with a water / fuel mass ratio of 0.89, at a rated gas generator speed of 48000 rpm.

The BSFC and thermal efficiency were improved by 51 and 20.3% respectively.

Increasing the atomization pressure to 3.5 bar would bring an extra boost in power of 1.6 % accompanied with the BSFC and thermal efficiency improvement of 2.6 and 0.9 % respectively.

A new parameter has been derived namely, Specific Cooling Rate, relating the resulted air cooling to the brake power output, showed an improvement of 17.6 % with 1.6 l / h of water sprayed into a 45oC air.

Nevertheless, when the injection rate has been raised to 4 l/h, the improvement reached 20.6 %.

Also, this parameter can be influenced by raising the atomization pressure to 3.5 bars as an extra 6.4 % improvement was observed correspondingly.

A computational model has been developed to study the evaporation dynamics of the injected droplets into the inlet duct of the gas turbine.

The model relies on the concept of discrete droplet in a separated flow based on the infinite conductivity formulation.

The predicted and measured data were compared to validate the effective length obtained.

The maximum deviation between them never exceeded 4.28 %, for all operational ranges that studied.

Main Subjects

Mechanical Engineering

Topics

• Fluid dynamics
• Aerodynamics
• Performance

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305196