Development of a Dual-Fuel Injection System for Lean Premixed Industrial Gas Turbines

Abstract

A fuel injection system for industrial gas turbine engines capable of using natural gas and liquid fuel in dry, lean premixed combustion is under development to significantly reduce NOx and CO emissions. The program has resulted in a design capable of operating on DF#2 over the 80 to 100% engine load range meeting the current TA LUFT regulations of 96 ppm (dry, @ 15% O2) NOx and 78 ppm CO. When operating on natural gas the design meets the guaranteed levels of 25 ppm NOx and 50 ppm CO. The design approach is to apply lean premixed combustion technology to liquid fuel. Both injector designs introduce the majority of the diesel fuel via airblast alomization into a premixing passage where fuel vaporization and air-fuel premixing occur. Secondary fuel injection occurs through a pilot fuel passage which operates in a partially premixed mode. Development is completed through injector modeling, flow visualization, combustion rig testing, and engine testing. The prototype design tested in development engine environments has operated with NOx emissions below 65 ppm and 20 ppm CO at full load. This paper includes a detailed discussion of the injector design and qualification testing completed on this development hardware.

Breakup Mechanism of a Jet in the L-Shape Crossflow of a Gas Turbine Combustor

“…In this equation, the SMD is proportional to We and Re. In the later research, the more sophisticated SMD correlation was suggested, which is the product of the We and Re with the exponent, as shown in Equation (8). Based on these correlations, many empirical equations related to the SMD have been intended for the jet breakup, and they have been mainly used to describe jet breakup mechanisms with a low injection pressure drop.…”

“…The jet-in-crossflow (JICF) method is a conventional, classical method that is mainly used in air-breathing propulsion systems. A JICF breaks the spray to mix the fuel and air using a large amount of air entering the combustor, and this method has advantages from the perspective of combustion stability, efficiency, and, in particular, emission reductions, which is a critical issue in today's world [1][2][3][4][5][6][7][8][9][10]. In previous studies, empirical correlations have been explored and developed for typical JICF methods, which inject fuel vertically into a horizontal airflow.…”

Environmental Upgrading of GTN-16 Gas-Pumping Unit Combustion Chamber

“…An annular prechamber for fuel/air premixing is placed downstream of the air wirier. The prechamber is made up of an outer cylindrical shell (2) and a swirler sleeve (3). A conic contraction (4) is placed downstream of the prechamber, this contraction hampering a flashback within the prechamber.…”

“…Many attempts have been made recently by quite a few companies to update gas turbine combustors to achieve a reduction in NOx emissions [1][2][3][4][5][6]. All the proposed engineering approaches involve a substantial gas turbine unit redesign including replacement of casing components and introducing changes in the automatic control system, etc.…”