Analysis on Operation Characteristics of 350 MW Waste Heat Boiler Under Variable Working Conditions

  Introduction  Integrated Gasification Combined Cycle (IGCC) power generation technology is a high-efficiency and low-carbon power generation technology. A waste heat boiler is one of the components of IGCC. This paper aims to study the off-design operating characteristics of waste heat boilers and improve the efficiency of integrated coal gasification combined cycle power generation technology.

  Method  The working principle and heat and mass transfer principle of the waste heat boiler were mainly analyzed by MATLAB software to carry out programming calculations to explore the relationship between feed water temperature, feed water pressure, liquid-phase heat transfer coefficient, gas-phase heat transfer coefficient and heat absorption in waste heat boiler.

  Result  The results show that when the liquid-phase heat transfer coefficient is in the range of 200～1 000 W/(m²·K) and the gas-phase heat transfer coefficient is in the range of 20～100 W/(m²·K), as if the feed water temperature increases from 30 ℃ to 100 ℃ or the feed water pressure increases, the heat absorption of the waste heat boiler decreases continuously. In case the feed water temperature is in the range of 30～100 ℃, when the liquid phase heat transfer coefficient increases from 200 W/(m²·K) to 1 000 W/(m²·K) or the gas phase heat transfer coefficient increases from 20 W/(m²·K) to 100 W/(m²·K), the heat absorption of the waste heat boiler increases continuously.

  Conclusion  Under the condition that liquid-phase heat transfer coefficient and gas-phase heat transfer coefficient remain unchanged, the feed water temperature or pressure increases, and the heat absorption capacity of the waste heat boiler will decrease; While the feed water temperature and pressure remain unchanged, the liquid-phase heat transfer coefficient or gas-phase heat transfer coefficient increases, and the heat absorption capacity of the waste heat boiler will increase.