Abstract : This paper briefly describes the principle of frequency converter control of heating furnace fan speed, details the energy-saving test of the first frequency converter replacing the fan butterfly valve, and promotes its application. After actual operation, the economic benefits were calculated using two methods: theoretical estimation of energy-saving benefits and calculation of energy-saving benefits by checking actual power consumption records, concluding that the energy-saving benefits are significant. Keywords : frequency converter; heating furnace; butterfly valve; blower; energy saving Our company is responsible for the crude oil transportation task from Qinhuangdao to Beijing. There are 15 heating furnaces in six oil stations on the Qinhuangdao-Beijing line. Currently, all of them have adopted Toshiba VF-A3 frequency converters to control the air volume, which has a significant energy-saving effect and low equipment maintenance. The application of energy-saving equipment is introduced in detail below. [b]1 Energy-saving transformation process using frequency converter 1.1 Energy-saving equipment - trial use of frequency converter[/b] In the past, the combustion air system of the heating furnace was controlled by a butterfly valve, as shown in Figure 1. The heating temperature is determined by the amount of fuel injected into the heating furnace (the fuel control system is irrelevant to this article; Figure 1 omits the fuel control system). The fuel quantity is measured by a fuel flow meter and sent to the controller (computer). The controller adjusts the opening of the butterfly valve according to the fuel quantity to achieve optimal air distribution. The combustion effect is best when the air-fuel ratio is 1:14 (1 kg of fuel to 14 m³ of air). Because the butterfly valve is installed in the air duct, even when fully open, there is a certain degree of throttling. In winter, under heavy load operation, some furnaces often experience insufficient airflow. In summer, under low load operation, the butterfly valve controls the airflow, and a smaller opening is sufficient to meet the airflow requirements. However, the power of the fan motor remains basically unchanged, and the throttling by the butterfly valve results in significant power loss. This is an extremely unreasonable "overpowered" situation. [b][align=center]For more details, please click: Energy-saving application of variable frequency speed control technology in heating furnace fans[/align][/b]