Search

A novel combustion gas and steam mixture cycle (GSMC) power generation system was simulated and studied in this paper. The system integrates the technologies of NG/O 2 combustion, energy storage, peak-shaving and CO 2 capture with LNG/LO 2 cold energy utilization, which has remarkable features such as high efficiency, low first/operation/maintenance costs, zero CO 2 and NO x emission and massive off-peak power shifting. A calculation case is presented and the impacts of turbine inlet parameters, condensing pressure/condenser outlet temperature and feedwater temperature on the net electric efficiency excluding ASU and equivalent net electric efficiency as well as CO 2 capture features are analyzed. The steam content in vapor phase of the condenser outlet is considered which requires more cooling capacity for CO 2 capture. Under the conditions that the condenser outlet temperature/condensing pressure is 30 °C/30 kPa and feedwater temperature is 300 °C, with fully CO 2 capture, the net electric efficiency excluding ASU and equivalent net electric efficiency are 0.4386 and 0.4105 respectively with turbine inlet parameters of 600 °C/30 MPa, and they can reach 0.5327 and 0.5046 respectively with turbine inlet parameters of 1000 °C/40 MPa. [ABSTRACT FROM AUTHOR]

A gas and steam mixture cycle (GSMC) is presented with a mixture of LNG/O 2 (liquid natural gas/oxygen) combustion product and feedwater as working medium, integrating features of high efficiency power generation, peak shaving, energy storage and CO 2 capture. The liquefied oxygen is produced during off-peak hours. During the operation hours, the cryogenic liquids of both LNG and oxygen are pumped to a high pressure and preheated before entering the combustors through the burners. The combustion product heats and mixes with the atomized feedwater to form supercritical H 2 O/CO 2 mixture vapor for power generation in a turbine unit. The CO 2 vapor is separated from condensate water in the condenser and liquefied by the cryogenic liquids of both LNG and oxygen after being compressed to a higher pressure. The circulation feedwater is injected to the annular channel between flame tube and shell cylinder of modular combustor via feedwater heating system. The results show that under the conditions of turbine inlet parameters of 40 MPa/800 °C and condensation temperature of 30 °C, the output power efficiency based on the thermal value of LNG fuel is 49.2% and the equivalent net efficiency is 46.4%, which accounts for 1/4 off-peak electricity consumption for liquid O 2 production. [ABSTRACT FROM AUTHOR]