Introduction  The applicability of the two schemes is analyzed through the application of planetary gear speed regulation and frequency conversion speed regulation in the energy-saving retrofit of the boiler electric feed pumps regulated by hydrodynamic couplings in the fossil-fuel power station.

  Method  Through the analysis of the energy consumption of the planetary gear speed regulation itself and the practical applications, and the comparison with the actual operation of the frequency conversion speed regulation, from the aspects of safety, applicability, adjustable range and energy saving, this paper discussed whether to use planetary gear speed regulation or frequency conversion speed regulation for energy-saving retrofit of boiler electric feed pumps regulated by hydrodynamic couplings in the fossil-fuel power station.

  Result  In the application, the frequency conversion speed regulation has a higher energy saving rate, wider adjustable range, and adequate safety guarantee, and is more applicable than the planetary gear speed regulation.

  Conclusion  The frequency conversion speed regulation is more suitable for the energy-saving retrofit of the boiler electric feed pumps regulated by hydrodynamic couplings in the thermal power station.