Steady-State Operation Characteristics of 100 MW Class Steam Turbine System

  Introduction  To effectively improve the cycle efficiency, the Integrated Gasification Combined Cycle (IGCC) power generation system has received extensive attention due to its advantages of high thermal efficiency, low pollution, and flexible operation. The waste heat boiler and the steam turbine together constitute the bottom cycle of the system.

  Method  Mainly combined with energy balance and thermodynamic calculation formula, using MATLAB for modeling operations, the effect of changes in steam flow, feed water temperature, superheated steam temperature, and reheat steam temperature on the steam turbine output power, thermal efficiency, and the total steam endothermic load was studied. At the same time, under the condition of steady-state operation, the working principle of the bottom cycle and the mass transfer and heat transfer process were analyzed.

  Result  The results show that increasing the high-pressure steam flow and reducing the low-pressure steam flow can make the steam turbine output higher power under the premise of higher thermal efficiency. Under the optimized operating parameters, the endothermic load is reduced by 45.7 kW compared with the reference operating condition, and the thermal efficiency is increased from 23.82% to 26.92%.

  Conclusion  The higher the temperature of high-pressure superheated steam and reheated steam, the higher the thermal efficiency of the steam turbine system, but the change range of heat absorption load and output power is very small. It can appropriately increase the temperature of high-pressure superheated steam and reheated steam, which is conducive to improving the thermal efficiency of the steam turbine.