Abstract: This paper introduces the operation, commissioning, and running status of the high-pressure ammonia pump and high-pressure methyl ammonium pump in the urea workshop of Sichuan Lutianhua Co., Ltd. after speed regulation by frequency converters, and analyzes the energy consumption and economic benefits of speed regulation by frequency converters for the high-pressure ammonia pump and high-pressure methyl ammonium pump. Keywords: Frequency converter, commissioning and operation, energy saving, economic benefits 1 Overview The carbon dioxide stripping urea plant of Sichuan Lutianhua Co., Ltd. has been in operation for nearly 30 years. To adapt to the needs of the situation, the plant's production capacity will be expanded from 1620 t/d to 2000 t/d. Some equipment can no longer meet the operating requirements after the expansion. Since the speed regulation system of the high-pressure ammonia pump (104-J/JS) and the high-pressure methyl ammonium pump (301-J/JS) uses traditional hydraulic torque converters, with the extension of service time, the hydraulic torque converters have gradually revealed many defects: equipment aging, regulation performance decreasing year by year, speed regulation lagging, control instability, large energy loss, increased failure frequency, and increased difficulty in maintenance. In particular, ordering spare parts is very difficult, and the foreign manufacturer has stopped producing the torque converter model used. Therefore, during the system overhaul in December 2002, the high-pressure ammonia pump and the ammonium carbamate pump were changed from torque converter speed regulation to more advanced frequency converter speed regulation. The high-pressure ammonia pump used a Rockwell high-voltage frequency converter from A-B Company (USA), but the motor remained unchanged, being an old 450/550kW, 6kV, 70A motor. Considering the difficulty in heat dissipation of the old motor at low speeds, the ventilation duct of the old motor was modified and a cooling fan was added. The ammonium carbamate pump used a low-voltage frequency converter from Siemens (Germany), and the motor was replaced with a 280kW, 690V, 277A frequency converter motor. At the same time, on-site operation control boxes for the high-pressure ammonia pump and the ammonium carbamate pump were added during the modification. [b][align=center]For details, please click: Analysis of the Operation of High-Pressure Ammonia Pump and Ammonium Carbamate Pump with Frequency Converter Speed ​​Regulation[/align][/b]