Numerical simulation of combustion characteristics in a 660 MW tangentially fired pulverized coal boiler subjected to peak-load regulation

Abstract

Coal power generation will be subjected to stringent peak-load regulation as renewable energy will become the mainstream option for the electrical power system in the future. Therefore, it is imperative to explore the combustion characteristics of coal-fired boilers in peak-load regulation. This paper aims to reveal the combustion characteristics of a 660 MW tangentially fired pulverized coal boiler under various loads in conjunction with different burner arrangements. The combustion characteristics of the furnace are analyzed under the context of boiler maximum continue rate, turbine heat acceptance and 75% turbine heat acceptance, respectively. The analytical results show that the middle tangential circle has a large diameter and that the flame tends to adhere to the wall. The overall combustion is relatively consistent when the same group of burners operate. It is basically similar to the change of component concentration in different cases. In comparison with other loads, the temperature reduction in the furnace under 75% turbine heat acceptance reduces NO by around 20%. In addition, by comparing the bottom burner group (ABCDE) with the upper burner group (BCDEF) under the same loads, it can be discovered that NO is reduced by roughly 70–80 ppm.

Keywords

• Pulverized coal boiler
• Tangentially fired
• Variable load combustion
• Numerical simulation
• Staging combustion