Eleventh International Conference on Climate Change: Impacts & Responses

Abstract

The United States consumed 38% of its total primary energy of 97.7 quadrillion Btu on its largest energy sector, the electric power generation in 2017. Adverse environmental impacts, carbon-induced global warming, and climate change and natural disasters from fossil-fuel fired electric utility power plants have caused much increased concerns in the past two decades. Performance improvement becoming a major need of the power sector aims at increasing energy efficiency, lowering air pollutants and CO 2 emission, and reducing costs for electricity. This paper explores different natural gas fueled triple- and quadruple-cycle for stationary electric power generation. The novel design can consist of a hybrid of modern gas turbine (GT) - steam turbine (ST) combined cycle integrated with pressurized solid oxide fuel cell (SOFC) and/or waste heat recovery organic Rankine cycle (ORC), totaling to three or four cycles (SOFC-GT- ST-ORC). A math model and numerical simulation of different design configurations of novel triple-/quadruple-cycle power plants are performed, optimized and assessed. Parametric studies for optimal efficiency and power output under different design/operation of major components and ORC fluids were conducted. Encouraging results of 70%-75% overall system efficiency can be obtained, which exceeds the current coal-fired ST power plants of 30%-45%, the modern ST-GT combined cycle power plants of 45% - 60%, and many proposed novel power plants of 55% - 65%. Effects and benefits of highly efficient power plants on fuel saving, carbon reduction, global warming and climate change will also be discussed.