Journal of Thermal Science Vol.18, No.3 (2009) 256−261 Received: March 2009 Yue WANG: Professor www.springerlink.com DOI: 10.1007/s11630-009-0256-5 Article ID: 1003-2169(2009)03-0256-06 Combustion of Hydrogen in an Experimental Trapped Vortex Combustor Hui Wu 1,2,* , Qin Chen 1,2 , Weiwei Shao 2 , Yongliang Zhang 1,2 , Yue Wang 2 , Yunhan Xiao 2 1. Graduate University of Chinese Academy of Sciences, Beijing 100049,China 2. Key Laboratory of Advanced Energy and Power, IET, CAS, Beijing 100190, China Combustion performances of pure hydrogen in an experimental trapped vortex combustor have been tested under different operating conditions. Pressure fluctuations, NOx emissions, OH distributions, and LBO (Lean Blow Out) were measured in the tests. Results indicate that the TVC test rig has successfully realized a double vortex con- struction in the cavity zone in a wide range of flow conditions. Hydrogen combustion in the test rig has achieved an excellent LBO performance and relatively low NOx emissions. Through comparison of dynamic pressure data, OH fluctuation images, and NOx emissions, the optimal operating condition has been found out to be Фp =0.4, fuel split =0.4, and primary air/fuel premixed. Keywords: trapped vortex combustor, hydrogen, combustion Introduction As the development of IGCC and zero CO 2 emission technology goes on, there is a demand for employing hydrogen rich fuels in gas turbines [1] . However, com- pared to natural gas, hydrogen is much more active. It has higher diffusion and reaction rate, higher speed of flame propagation, and also higher adiabatic flame tem- perature. Accordingly, there would be many problems for a traditional swirl burner to make use of hydrogen rich fuels, such as flash back, local high temperature, and high NOx emissions [2] . Therefore, it is necessary to de- velop a new combustion technology for the utilization of hydrogen rich fuels in gas turbines. The Trapped Vortex Combustor (TVC) is an advanced concept in combustor design. It was developed by the Air Force Research Laboratory and General Electric Aircraft Engines in the U.S. [3,4] , and has been widely studied for aircraft engine applications [5-7] , recently also for station- ary gas turbine combustor applications as well [8,9] . De- tailed experimental tests have demonstrated that trapped vortex combustor has extraordinary performances, such as high combustion efficiency, low NOx emission, re- duced lean blow out, increase in altitude re-light, and so on [10] . More importantly, it has been considered by many researchers that TVC might be a unique candidate for hydrogen rich fuel combustor, due to its special principle for flame stabilization and excellent performances under high flow velocity [11] . However, few tests have been ac- tually done for burning pure hydrogen in a TVC proto- type. The purpose of this paper is to test the combustion performances of pure hydrogen in an experimental TVC test rig, so that to confirm the availability of TVC con- cept as a competitive candidate for hydrogen rich fuel combustor, and to discover the facts that influence the combustion performances, so that to find out an optimal operating mode. Experimental Apparatus The TVC test rig is in an outer cavity structure, shown in figures 1 and 2 (dimensions are in millimeter). Primary fuel and air enter into the cavity through lines of injection