Shenmu Energy saves 2 million yuan by using variable frequency drives for water pump renovation

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Shenmu Energy Saves 2 Million Yuan by Upgrading Pump Frequency Converters; Author/Source: Shaanxi Petrochemical News Network; Date: 2020-07-21; Clicks: 115. Recently, the frequency converter upgrades installed on Shenmu Coal Chemical Energy Company’s No. 6 and No. 3 feed pumps have been in use successfully for 2 years now. It not only extends the motor’s service life and ensures the stable operation of the equipment, but also generates savings of over 2 million yuan in total. The feed water pump is an important rotating equipment in power plants, playing a crucial role in power generation. During normal load increases and decreases, since the feed water pump is not equipped with an inverter, it cannot operate at variable frequency; startup can only take place at a power frequency of 50 Hz. The starting current is 5-6 times higher than the rated current, which severely affects the service life of the motor. During low-load operation, running the feed water pump at a high power frequency also results in significant electricity consumption, increasing production costs. Through visits, studies, and investigations, the company developed a plan to carry out variable-frequency conversion on the feed water pumps. In June 2018, a frequency converter was first installed on Pump No. 6; after the modification, it operated well, reducing power consumption by 200 KW per hour. In January 2019, the No. 3 feed water pump was further upgraded with variable frequency technology and an automatic bypass cabinet was installed, enabling seamless switching between normal frequency and variable frequency operation; this reduced power consumption by 250 KW per hour. By installing an inverter, soft starting of the motor and power compensation can be achieved; energy-saving speed control is accomplished by adjusting the frequency of the voltage supplied to the equipment, and protection functions against overcurrent, overvoltage, overload, etc. are provided for the equipment. According to statistics, after the frequency conversion modification of pumps No. 6 and No. 3, with an average power savings of 225 KW per hour, cumulative savings of over 2 million yuan can be achieved. This solution also eliminates problems such as loud noise during startup at line frequency, high starting current, and the tendency for high-voltage motors to trip, thereby providing a solid foundation for the long-term operation of the machinery. (