4 Advanced steam cycles Report B

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Alessandro Artoni Alberto Bortolotti In this project we want to calculate the performance of diverse steam cycle configurations throughout the use of the software package CicVap. As reference plant we are considering the USC (Ultra SuperCritical) steam cycle, namely configuration A. Configuration A - Superheater outlet mass flow rate: 1˙850˙000 kg/h - Superheater outlet steam pressure: 270 bar - n° re-heaters: 1 - n° pre-heaters (deaereator included) : 8 (4 BP, 4 AP) - n° intermediate-pressure two-flow rotors: 2 - n° low-pressure two-flow rotors: 4 - last stage blading: 33.5 inches – mean diameter 99.5 inches - steam temperatures: 580°C / 580°C - condensing pressure: 0.05 bar - fuel: coal - exhaust gases stack temperature 150 °C - O2 concentration in exhaust gases at the stack: 5% - economiser water inlet temperature: ~ 315 °C Furthermore, consider the following cycle configurations which are different from configuration A by the hereby mentioned characteristics (all the parameters which have not been reported remain equal to the former case A): Configuration B - fuel: natural gas - exhaust gases stack temperature: 120 °C - stack O2 concentration in exhausts: 2.5% Configuration E - n° regenerators: 4 (2 LP deaereator included, 2 HP) - economiser water inlet temperature: ~ 280 °C Configuration C - condensing pressure: 0.1 bar Configuration F - n° re-heaters: 2 - steam temperatures: 580°C/580°C/580°C Configuration D - steam temperatures: 640°C / 640°C It is required to perform the calculation of the cycle for each configuration. Post-­‐process the entropy analysis results given by the software, grouping the irreversibilities as follows: -­‐ combustion related losses (including air and fuel pre-­‐heating); -­‐ cycle heat introduction losses: heat exchange between exhausts…