Abstract : This article introduces the working principle of high-voltage frequency converters and the energy-saving principle of variable frequency speed control devices. Taking the application of high-voltage frequency converters in the primary air fan and turbine condensate pump of the 2 x 220 MW heating unit of Shanxi Datang International Yungang Thermal Power Co., Ltd. as an example, the energy-saving effect is analyzed.
Keywords : High-voltage frequency converter; Thermal power plant; Fan; Condensate pump; Energy saving
1 Overview
In today's energy-scarce world, conservation is undoubtedly the best approach. In my country's power generation energy mix, thermal power accounts for over 70%, making thermal power plants both producers and consumers of electricity. Typically, the power consumed by a thermal power unit is only 4% to 7% of its generating output, and the high-voltage motors driving large-capacity fans and pumps account for about 80% of the plant's power consumption. With the separation of power plants and grids and the increasing marketization of power generation enterprises, coal consumption and power consumption rate have become crucial indicators for evaluating power plants, directly impacting their economic efficiency and competitiveness. The energy-saving effect of variable speed control for fans and pumps can significantly reduce power consumption rate and generation costs; the adoption of high-voltage frequency converters can save 30% to 60% of the plant's power consumption in thermal power plants.
In my country, most thermal power plants draw their auxiliary power from 6 kV busbars, and all high-power motors utilize this voltage level. A single 50,000 kW thermal power generating unit typically uses more than 20 high-voltage motors. Considering operational conditions, at least 10 motors in each unit are potentially eligible for frequency conversion energy-saving retrofitting. Therefore, the energy-saving potential of frequency conversion retrofitting for auxiliary equipment such as fans and pumps in my country's thermal power plants is significant, yielding substantial economic and social benefits.
For details, please click: Application of High-Voltage Frequency Converters in Thermal Power Plants
