4 Advanced steam cycles Report A

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Course of Energy Conversion A 2014/2015 Prof. G. Valenti _________________________________________________ 4th project Advanced steam cycles Index: 1. Introduction; 2. Entropic analysis for all configurations ; 3. General results and comments 1. Introduction Steam cycle are really important in electric power generation nowadays. In this project we will analyze six different configuration, starting from a basic configuration and varying some of the plant parameters such as: • Fuel • Regenerators number • Reheaters number • Condensing pressure • Economizer water inlet • Maximum temperature of the cycle The starting configuration is typical for large scale steam power plant: • Superheater outlet mass flow rate: 1˙850˙000 kg/h • Superheater outlet steam pressure: 270 bar • n re-heaters: 1 • n pre-heaters (deaerator 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% • economizer water inlet temperature: ~ 315 °C Thanks to CICVAP we perform easily the analysis of the plant both in terms of first law and second law. We report in a table and with some graphs the entropy analysis of the plant dividing the irreversibilities: • combustion related losses (including air and fuel pre-heating); • cycle heat introduction losses: heat exchange between exhausts and isothermal line at Tmax ; • cycle heat introduction losses: heat exchange between isothermal line at Tmax – steam; • regeneration related losses (deaerator included); • cycle waste heat losses; • working fluid compression losses; •…