TITLE: Thermodynamic Evaluation of Advanced Combined Cycle Burning Hydrogen

Authors

Dr. Sanjay, Assistant Professor, Mechanical Engg. Department, NIT, Jamshedpur, INDIA, ritsanjay@rediffmail.com

Prof. Onkar Singh, Mechanical Engg. Department, HBTI, Kanpur, INDIA, onkpar@rediffmail.com

<>ABSTRACT

The present work deals with the thermodynamic evaluation of gas turbine based combined cycle using the latest gas turbines e.g. ABB GT26 gas turbine (advanced) burning hydrogen. The bottoming cycle is an alteration from the traditional HRSG based steam generation system. The proposed cycle burns hydrogen and the gas turbine exhaust gas instead of generating steam in HRSG is allowed to expand in a separate steam turbine upto condenser pressure.

The gas turbine (ABB GT26) is reheat of type and the blade cooling is done by air bled from compressor. The same turbine is subjected to closed loop steam cooling. Parametric study has been performed on plant efficiency and specific work for various independent  parameters such as turbine inlet temperature, compressor  pressure ratio, reheating pressure ratio, reheater inlet  temperature, blade temperature, etc.. It has been observed that due to higher compressor pressure ratio involved in reheat gas turbine combined cycle and higher temperature of exhaust, the plant efficiency and specific work are higher with the advanced reheat gas/steam combined cycle over the simple combined cycle. The effect of using hydrogen fuel instead of traditional natural gas is significant on cycle performance. Steam cooling offers better performance over air-cooling.