Application of FGI frequency converter in steam compressor
1. Introduction
Alumina plants and electrolytic aluminum plants are large power consumption, which need a lot of electricity. If only the electricity from the state grid is used, the cost is high, and the production is limited when the power is tight. In addition, the secondary steam of the power plant needs to be used in a lot, so the aluminum power base generally has its own self-provided power plant.
The company's power plant equipment includes 3155MW steam turbine generator sets and 4520t / h boilers (3 of which are for operation and 1 is for standby). Each steam turbine is equipped with two circulating pumps, named A and B circulating pumps respectively, and the whole power plant has 6 circulating pumps. Under normal operation conditions, each turbine only uses one of the A or B circulating pump, and the other one serves as standby. The circulating water pump is replaced every 3 months. The circulating water pump motor has two taps, respectively, high speed 495rpm, power 1600kW, and low speed 425rpm, power 1250kW / 1120kW. The speed regulation strategy varies according to the season, using the motor at high speed to meet a large amount of water supply in summer, and using the motor at low speed in winter to meet a small water supply demand.
2. Implementation plans
The company chose the FGI high voltage inverter FD5000 series, based on its advanced control technology and efficient energy efficiency optimization design. FD5000 Series adopts the advanced vector control technology, which can accurately control the operating state of the high-pressure system, maximize the energy efficiency of the system, and reduce the energy consumption. Using the intelligent energy consumption management system, the FD5000 series monitors the heating demand in real time and automatically adjusts the operating parameters of the system to meet the real-time demand in the best way, so as to reduce energy consumption and reduce operating costs. The stability and reliability of FD5000 series ensure the long time stable operation of the high voltage system in extreme climate conditions, reduce the system failure rate, and improve the reliability of the system.
The company's power plant introduced FGI FD5000 high voltage frequency converter, which realized the remote control and local control, thus improving the safety of the system and the flexibility of operation. Through the existing DCS system, the operation status of the high voltage inverter is monitored, and the remote control of the inverter is realized. In addition, the system provides local manual and automatic control functions to operate through the corresponding buttons and operators. In the operation mode of FD5000 high voltage frequency converter, when the frequency converter or water pump failure causes the high voltage circuit breaker to jump off, the system can automatically put the standby circulating water pump into operation to ensure the safe operation of the generator set. FD5000 The switching volume output provided by the high voltage frequency converter to the DCS includes fault alarm, readiness indication, operation indication, high voltage closing permit, joint jump high voltage signal, pump bypass switch closing signal, and frequency conversion KM1 closing signal. The switching amount provided by DCS to FD5000 high voltage frequency converter includes frequency conversion start, frequency conversion stop, frequency conversion emergency stop and other signals, which are used to realize the start and stop and emergency stop of the frequency converter. By introducing FD5000 high voltage frequency converter, the system realizes advanced control functions and improves the stability, safety and energy efficiency of the system. FD5000 The cooperation of the high voltage frequency converter and the existing system makes the operation of the generator set more intelligent and reliable.
3.Application advantage
Speed regulation of frequency converter: using high voltage frequency converter, it can be used to adjust the speed of the circulating water pump motor according to the actual needs. This allows the flexible adjustment of the cooling water quantity of the pump according to the unit load, external environment and season, so as to realize the economic operation.
Energy saving and consumption reduction: through frequency conversion speed regulation, can effectively reduce the power consumption of the motor. This helps reduce the power consumption rate, reduce the cost of power generation and improve the efficiency of power plants.
Vacuum control: The speed regulation function of the frequency converter makes the circulating water quantity can be adjusted more accurately to meet the vacuum control requirements of the unit under the changing operating conditions.
Improve safety: through flexible speed adjustment, it can better adapt to different seasons and load changes, and improve the safety and stability of the unit.
Power grid pressure solution: the existence of self-provided power plants can solve part of the problem of limited production due to power shortage, reduce the over-dependence on the national grid, and thus improve the reliability of power plants.
Remote monitoring: high voltage frequency converter is usually equipped with advanced remote monitoring system, which can realize remote monitoring and adjustment of motor and system and improve the efficiency of operation and maintenance.
