Combined cycle power plant with integrated low temperature heat (LOTHECO)

• Published in: Applied thermal engineering Vol. 24; no. 11; pp. 1677 - 1686
• Main Authors: Kakaras, E, Doukelis, A, Leithner, R, Aronis, N
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2004; Elsevier
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Exergo-economic analysis; Gas turbine technology; Heat transfer; Process simulation of thermal power plants; Theoretical studies. Data and constants. Metering; Gas turbine technology; Exergo-economic analysis; Process simulation of thermal power plants; Electric power plant; Costs; Cooling; Thermodynamic cycle; Evaporation; Droplet; Thermodynamics; Compressed air; Combustion chamber; Electricity; Exergy analysis; Heat balance; Gas turbine; Natural gas; Low temperature
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2003.10.030

The major driver to enhance the efficiency of the simple gas turbine cycle has been the increase in process conditions through advancements in materials and cooling methods. Thermodynamic cycle developments or cycle integration are among the possible ways to further enhance performance. The current paper presents the possibilities and advantages from the LOTHECO natural gas-fired combined cycle concept. In the LOTHECO cycle, low-temperature waste heat or solar heat is used for the evaporation of injected water droplets in the compressed air entering the gas turbine's combustion chamber. Following a description of this innovative cycle, its advantages are demonstrated by comparison between different gas turbine power generation systems for small and large-scale applications, including thermodynamic and economic analysis. A commercial gas turbine (ALSTOM GT10C) has been selected and computed with the heat mass balance program ENBIPRO. The results from the energy analysis are presented and the features of each concept are discussed. In addition, the exergy analysis provides information on the irreversibilities of each process and suggested improvements. Finally, the economic analysis reveals that the combined cycle plant with a heavy-duty gas turbine is the most efficient and economic way to produce electricity at base load. However, on a smaller scale, innovative designs, such as the LOTHECO concept, are required to reach the same level of performance at feasible costs.