An evaluation of the thermodynamic potential of high-pressure part-flow evaporative gas turbine cycles
2004 (English)In: Energy-Efficient, Cost-Effective and Environmentally-Sustainable Systems and Processes, Vols 1-3 / [ed] Rivero, R; Monroy, L; Pulido, R; Tsatsaronis, G, 2004, 1053-1066 p.Conference paper (Refereed)
Evaporative gas turbine cycles (EvGT) are advanced gas turbine cycles which utilise an air-water mixture as the working fluid in the turbine expander. The EvGT cycles studied in this article are further characterised by their use of humidification towers to introduce water vapour to the compressed working fluid. This article examines the thermodynamic potential of intercooled EvGT cycles, with the focus on working pressures over 50 bar and part-flow configurations. Along with known evaporative cycles, a new configuration is introduced and studied: the so-called high-pressure part-flow EvGT cycle (HP-PEvGT). The study found that all intercooled evaporative gas turbine cycles have efficiency optimums at pressures well over 40 bar for relevant firing temperatures, with the pressure optimum defined by internal cycle dynamics. The novel part-flow configuration and self-recuperative humidification circuit of the HP-PEvGT allow this cycle to reach higher pressures and efficiencies than conventional evaporative cycle configurations. Boilers should be utilised where the gas turbine exhaust temperatures are high to enable the humidification tower to operate more effectively. While a triple pressure combined cycle was found to be more efficient than evaporative cycles at current gas turbine operating pressures (20-40 bar), the HP-PEvGT cycle has a significantly higher efficiency potential, Furthermore, much higher power densities are found for evaporative cycles, especially when they are simulated at high pressure. Despite the technical challenges of high-pressure evaporative cycles, the gains in efficiency and power density plus the more compact heat recovery system may make such a development worthwhile.
Place, publisher, year, edition, pages
2004. 1053-1066 p.
evaporative gas turbine cycles, high pressure, part-flow, humidification, humidification tower, steam-injection
IdentifiersURN: urn:nbn:se:kth:diva-44693ISI: 000232747300094ISBN: 968-489-027-3OAI: oai:DiVA.org:kth-44693DiVA: diva2:451903
17th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy and Process Systems (ECOS 2004) Location: Guanajuato, MEXICO Date: JUL 07-09, 2004
QC 201110272011-10-272011-10-252011-10-27Bibliographically approved