Abstract

This paper discusses the application of global trends in gas cycles technology using oxy-fuel combustion. This is followed by a demonstration of a design solution for a new cycle with two enhanced energy-converting devices, namely a wet combustion chamber and a spray-ejector condenser. The proposed gas and steam cycle unit is contained within a single turbine, whose benefits combine those offered by gas turbines (high inlet temperatures) and steam turbines (full expansion into a vacuum). The efficiency of the oxy-fuel combustion system with carbon dioxide capture was determined based on thermodynamic analyses carried out using in-house codes (COM-GAS). The motivation behind this research paper was provided by calls for diversification in the power generation industry in Poland as well as the need for new solutions in power plants, including compact ones. Compactness can be achieved when the plant is rid of its largest components such as the heat recovery steam generator and the conventional steam condenser. For this, it would be necessary to design non-standard cutting-edge devices, but the counterbalancing pay-off would be in their size, reduced to the point where power plants, in which they are installed, will be able to adequately address the needs of urban users and cater for heat production demand. The concept under consideration is based on the use of shale gas deposits in the place of extraction in a compact, zero-emission gas-steam turbine power system. In our case power plant compactness is achieved by using two new devices, namely: 1) a wet combustion chamber (with oxy-combustion and combustion chamber walls cooling by thermal transpiration); 2) a condenser spray-ejector (using a bulk condensation of vapor-gas). The main aim of the spray-ejector condenser is simultaneously condensing steam and compressing CO2 from the condensation pressure to about 1 bar. Hence, the most important innovation of this steam-gas cycle emerges as the enhanced condensation, which is based on the nano-injection of cold water and a jet-powered compression of CO2 performed in the spray-ejector condenser.

Authors (2)