TY - JOUR

T1 - A LIF Study of the Temperature Field behind the Pilot Flame Front of a Gas Turbine Type Model Combustor

AU - Savitskii, A. G.

AU - Sharaborin, D. K.

AU - Dulin, V. M.

AU - Markovich, D. M.

N1 - This study was financially supported by the Russian Science Foundation (grant no. 19-79-30075). The equipment was provided within the framework of the state contract with the Institute of Thermal Physics, Siberian Branch, Russian Academy of Sciences. Публикация для корректировки.

PY - 2023/5

Y1 - 2023/5

N2 - The problem of reducing the amount of harmful emissions during the operation of gas turbine units (GTUs) has become especially important in recent years. In this regard, for optimizing the flow thermal and gas dynamic processes, the flow velocity and the combustion process in the GTU combustion chambers have to be studied in detail. Such optimization makes it possible not only to secure highly complete fuel combustion and stable operation of the burners in a wide range of the fuel to oxidizer ratios but also to decrease the amount of harmful emissions. The article deals with studying the temperature field structure of the pilot flame produced by a model gas turbine two-zone burner. The instantaneous temperature distribution in the flame was recorded using the method based on thermally-assisted planar laser-induced fluorescence (PLIF) in exciting the Q 1(8) transition band (1–0) of the A2Σ+–X2Π OH hydroxyl radical electron system. The study was carried out for the case of combusting a partially mixed methane and air mixture with a significant Air-fuel ratio α = 1.54 under standard conditions in swirl flow at the Reynolds number Re = 1.5 × 104. The procedure of calibrating a thermally assisted PLIF system with using a thermocouple is described in detail. The article also presents instantaneous temperature distribution patterns downstream of the flame front in the range 1500–2000 K. The obtained data show that the temperature field features a significant heterogeneity due to the flame being stabilized at the central fuel flame periphery by a swirl mixing air flow. The conditional averaging of the temperature field with taking into account the alternation caused by the flame’s front motion testifies that the temperature at the front base is close to the minimal adiabatic temperature values of the premixed mixture near the “lean” (α > 1, i.e., when the amount of oxidizer (air) is larger than that necessary for complete fuel combustion) flammability limit.

AB - The problem of reducing the amount of harmful emissions during the operation of gas turbine units (GTUs) has become especially important in recent years. In this regard, for optimizing the flow thermal and gas dynamic processes, the flow velocity and the combustion process in the GTU combustion chambers have to be studied in detail. Such optimization makes it possible not only to secure highly complete fuel combustion and stable operation of the burners in a wide range of the fuel to oxidizer ratios but also to decrease the amount of harmful emissions. The article deals with studying the temperature field structure of the pilot flame produced by a model gas turbine two-zone burner. The instantaneous temperature distribution in the flame was recorded using the method based on thermally-assisted planar laser-induced fluorescence (PLIF) in exciting the Q 1(8) transition band (1–0) of the A2Σ+–X2Π OH hydroxyl radical electron system. The study was carried out for the case of combusting a partially mixed methane and air mixture with a significant Air-fuel ratio α = 1.54 under standard conditions in swirl flow at the Reynolds number Re = 1.5 × 104. The procedure of calibrating a thermally assisted PLIF system with using a thermocouple is described in detail. The article also presents instantaneous temperature distribution patterns downstream of the flame front in the range 1500–2000 K. The obtained data show that the temperature field features a significant heterogeneity due to the flame being stabilized at the central fuel flame periphery by a swirl mixing air flow. The conditional averaging of the temperature field with taking into account the alternation caused by the flame’s front motion testifies that the temperature at the front base is close to the minimal adiabatic temperature values of the premixed mixture near the “lean” (α > 1, i.e., when the amount of oxidizer (air) is larger than that necessary for complete fuel combustion) flammability limit.

KW - alternation ratio

KW - laser-induced fluorescence

KW - methane–air mixture

KW - planar thermometry

KW - turbulent swirl flame

KW - vortex combustion chamber

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85159442252&origin=inward&txGid=0b099ad1be7d19b8976cdc1eb370d7e8

UR - https://www.mendeley.com/catalogue/e5c0a515-13a4-35f6-a36c-17386ac01579/

U2 - 10.1134/S0040601523050051

DO - 10.1134/S0040601523050051

M3 - Article

VL - 70

SP - 354

EP - 361

JO - Thermal Engineering (English translation of Teploenergetika)

JF - Thermal Engineering (English translation of Teploenergetika)

SN - 0040-6015

IS - 5

ER -