An experimental/computational study of airflow in the combustor-diffuser system of a gas turbine for power generation

Journal Article · Thu Jan 01 04:00:00 EST 1998 · Journal of Engineering for Gas Turbines and Power

DOI:https://doi.org/10.1115/1.2818084· OSTI ID:290099

Agrawal, A K ^[1]; Kapat, J S ^[2]; Yang, T T ^[3]

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1. Univ. of Oklahoma, Norman, OK (United States). School of Aerospace and Mechanical Engineering
2. Univ. of Central Florida, Orlando, FL (United States)
3. Clemson Univ., SC (United States). Dept. of Mechanical Engineering

This paper presents an experimental/computational study of cold flow in the combustion-diffuser system of industrial gas turbines employing can-annular combustors and impingement-cooled transition pieces. The primary objectives were to determine flow interactions between the prediffuser and dump chamber, to evaluate circumferential flow nonuniformities around transition pieces and combustors, and to identify the pressure loss mechanisms. Flow experiments were conducted in an approximately one-third geometric scale, 360-deg annular test model simulating practical details of the prototype including the support struts, transition pieces, impingement sleeves, and can-annular combustors. Wall static pressures and velocity profiles were measured at selected locations in the test model. A three-dimensional computational fluid dynamic analysis employing a multidomain procedure was performed to supplement the flow measurements. The complex geometric features of the test model were included in the analysis. The measured data correlated well with the computations. The results revealed strong interactions between the prediffuser and dump chamber flows. The prediffuser exit flow was distorted, indicating that the uniform exit conditions typically assumed in the diffuser design were violated. The pressure varied circumferentially around the combustor casing and impingement sleeve. The circumferential flow nonuniformities increased toward the inlet of the turbine expander. A venturi effect causing flow to accelerate and decelerate in the dump chamber was also identified. This venturi effect could adversely affect impingement cooling of the transition piece in the prototype. The dump chamber contained several recirculation regions contributing to the losses. Approximately 1.2 dynamic head at the prediffuser inlet was lost in the combustor-diffuser.

• Sponsoring Organization: USDOE Morgantown Energy Technology Center, WV (United States)
• DOE Contract Number: AC21-89MC26041
• OSTI ID: 290099
• Report Number(s): CONF-960608--
• Journal Information: Journal of Engineering for Gas Turbines and Power, Journal Name: Journal of Engineering for Gas Turbines and Power Journal Issue: 1 Vol. 120; ISSN JETPEZ; ISSN 0742-4795
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
AIR FLOW
COMBUSTORS
COMPUTER CALCULATIONS
DIFFUSERS
GAS TURBINES