EXPERIMENTAL EVALUATION OF TWO PREMIXING PREVAPORIZING FUEL INJECTION CONCEPTS FOR A GAS TURBINE CATALYTIC COMBUSTOR

摘要

Experiments were performed to evolve and evaluate a premixing-prevaporizing fuel system to be used with a catalytic combustor for possible application in an automotive gas turbine. Spatial fuel distribution and degree of vaporization were measured using Jet A fuel. Two types of air blast injec¬tors were tested, a splash-groove injector and a multiple-jet cross-stream injector. Air swirlers with vane angles of 15° and 30° were used to improve the spatial fuel distribution. The work was done in a 12-cm (4.75-in.) diameter tubular rig. Distribution and vaporization measurements were made 35.5 cm (14 in.) downstream of the injector. Test conditions were: a pressure of 0.5 MPa (5 atm), inlet air temperatures up to 800 K (980° F), velocity of 20 m/sec (66 ft/sec) and fuel-air ratios of 0.01 and 0.025. The spatial fuel distribution was nearly uniform with the multiple-jet contrastream injector and the splash-groove injector with a 30° air swirler. The vaporization was nearly 100 percent at an inlet air temperature of 600 K (620° F) and at an 800 K (980° F) inlet air temperature fuel oxidation reactions were observed. The total pressure loss was less than 0. 5 percent of the total pressure for the multiple-jet cross-stream injector and the splash-groove injector (without air swirler) and less than 1 per¬cent for the splash-groove with a 30° air swirler for the above test conditions.