Development and Testing of a Low NOx Hydrogen Combustion System for Heavy-Duty Gas Turbines

Abstract

Interest in hydrogen as a primary fuel stream in heavy-duty gas turbine engines has increased as precombustion carbon capture and sequestration (CCS) has become a viable option for integrated gasification combined cycle (IGCC) power plants. The U.S. Department of Energy has funded the Advanced IGCC I Hydrogen Gas Turbine Program since 2005 with an aggressive plant-level NO^ target of 2 ppm at 15% O2for an advanced gas turbine cycle. Approaching this NO^ level with highly reactive hydrogen fuel at the conditions required is a formidable challenge that requires novel combustion technology. This study begins by measuring entitlement NO^ emissions from perfectly premixed combustion of the high-hydrogen fuels of interest. A new premixing fuel injector for highhydrogen fuels was designed to balance reliable flashback-free operation, reasonable pressure drop, and low emissions. The concept relies on small-scale jet-in-crossflow mixing that is a departure from traditional swirl-based premixing concepts. Single nozzle rig experiments were conducted at pressures of 10 atm and 17 atm, with air preheat temperatures of about 650 K. With nitrogen-diluted hydrogen fuel, characteristic of carbon-free syngas, stable operation without flashback was conducted up to flame temperatures of approximately 1850 K. In addition to the effects of pressure, ihe impacts of nitrogen dilution levels and amounts of minor constituents in ihe fuel-carbon monoxide, carbon dioxide, and methane-on flame holding in the premixer are presented. The new fuel injector concept has been incorporated into a full-scale, multinozzle combustor can with an energy conversion rate of more than 10 MW at F-class conditions. The full-can testing was conducted at full gas turbine conditions and various fuel compositions of hydrogen, natural gas, and nitrogen. This combustion system has accumulated over 100 h of fired testing at full load with hydrogen comprising over 90% of the reactants by volume. NOê missions (ppm) have been measured in the single digits with hydrogen-nitrogen fuel at target gas turbine pressure and temperatures. Results of the testing show that small-scale fuel-air mixing can deliver a reliable, low-NO^ solution to hydrogen combustion in advanced gas turbines.

Frontiers in combustion techniques and burner designs for emissions control and CO2capture: A review

“…The main features of the MM technology are staging capability, scalability, and fuel flexibility. York et al 238 conducted a full-can durability test of MM nozzles at the combustion conditions of General Electric's F-class gas-turbine at full load conditions considering air combustion of fuel blends of hydrogen, nitrogen, and natural gas. Using a fuel blend of hydrogen and nitrogen (hydrogen is more than 90% by volume) and after 100 hours of firing, NO x emissions were at the level of single-digit ppm.…”

“…Some of the examined configurations were jetin-crossflow mixing, 242 co-flow mixing, 243 and swirlinduced mixing in miniature cups with axial and radial inflow. 244 The combustion of high-H 2 fuels using air in MMs has been examined in past studies, [238][239][240] but never under oxycombustion conditions. Hernandez et al 245 natural gas/air ones in MMs.…”

A Real-Time Combustion Instability Simulation with Comprehensive Thermo-Acoustic Dynamic Model

“…Thermo-acoustic problems may also occur, largely due to the geometric shape of the combustor structure and chemical reactions during combustion, leading to combustion instability [14]. Among other reasons, the combustion instability occurs in the combustor chamber due to acoustic oscillations in the chamber, which are produced by interactions between the heating mechanism and pressure oscillations [15,16].…”

Investigation of a pure hydrogen fueled gas turbine burner

“…These changes were focused on achieving three different fuel/air mixing profiles while maintained similar equivalence ratio operational ranges; as other cases, the engine fueled with hydrogen produced larger volumes of NOx. Other innovative technologies are described in the literature, for example, the Micro-mixing [25], the Multi-Tube Mixing [26] or the Lean Direct Injection [27]. These designs are characterized by the using of small passage as a premixing duct to reduce the flashback and improvement the NOx production control, but all this solution is far to a great operability with pure hydrogen in a gas turbine.…”

“…The design activity and the preliminary experimental data are reported in Brunetti et al [28], which are focused on the effect of hydrogen content on the main operating parameters. The aim of this paper is the investigation of the pure H2 fueling because in literature deep analyses on only this condition are few also for the other cases, as in Galletti et al [29] and York et al [26].…”