Energy saving application and effect analysis of high voltage inverter in water works
The maturity of AC motor frequency conversion speed regulation technology, especially computer control technology, makes PLC and frequency conversion speed regulation more closely integrated, and can play a more positive role in water plants.
The frequency conversion speed control system for water supply in water plants has the advantages of simple operation, high reliability, high anti-interference, constant water supply pressure, and energy saving and high efficiency; at the same time, with the help of more in-depth application of the system, water plants can be unattended; in addition , the system can realize the soft start and soft stop of multiple pumps, and minimize the water hammer effect of the pipe network easily caused by the traditional operation method; with the help of network communication technology, it can realize remote data maintenance and remote control of the pump room, Expand the operational flexibility of the frequency converter and improve its operational reliability.
3.1 Optimization and improvement of PLC control system
The water supply frequency conversion speed regulation system mainly includes three parts: the on-site control layer, the control trunk layer and the management layer. If the system adopts DCS (distributed control system) structure, the realization difficulty is relatively low. The control mode of DCS adopts the multi-level control mode of "distributed control and centralized management". Although the functions are scattered, the reliability of the system has been improved. In addition, the development trend of modern management should also be an important issue that the water plant needs to consider at present: the management network of the water plant should include the computer system in the central control room. In addition, in order to realize data sharing, various data collected by the water plant are Input into the server of the management network system; production data and management data are stored in the same database, and can monitor the actual operation of the water plant in real time; in addition, the server adopts dual hard disk configuration, which improves data security; customer The terminal and server use 100Mb network card to improve the transmission speed of information.
3.2 Frequency conversion technology and the application of frequency converter in water supply of water plants
The frequency conversion technology and the frequency converter have a very high power saving rate, and their energy saving and consumption reduction effect is remarkable, which can not only save the waste of resources caused by the redundant design of the water plant, but also obtain better operating benefits due to the high power factor and speed regulation accuracy. . Frequency conversion technology can reduce the loss of equipment and materials, reduce mechanical noise and loss, and can also effectively improve the quality and quantity of water supply to meet the dynamic requirements of the production process.
4. Operation of frequency conversion speed control system
The company's frequency conversion speed control system operates continuously and uninterruptedly around the clock. When the system runs in the state of power frequency and the actual pressure value of the pump port is far from the given value, a power frequency unit is started to meet the water consumption requirements. At this time, through the adjustment of the frequency conversion system, the water flow meets the water flow requirements.
The setting of the given value of the pump port pressure is generated according to the historical data analysis of the water flow demand curve of the four seasons and the all-day water demand curve. When the urban water supply pipe network is in normal operation, the frequency conversion system operates in a closed loop according to the given value; when the urban pipe network is abnormal, the given value can be changed in real time on the host computer to meet the water supply demand.
Through the operation of the variable frequency speed control system for 5 years, the water and electricity consumption per thousand tons has been significantly reduced. According to the calculation (excluding the maintenance time, it is calculated as 340 days of annual operation, saving 1440kW/d per day). The annual energy saving is about 49×104kW·h, which is a significant It reduces the number of starts and stops of the power frequency motor, reduces the work intensity of the pump room staff, the pressure curve of the pump port tends to be smooth, eliminates the pipe burst caused by the high pressure of the pipe network, and reduces the water leakage during the operation of the pipe network. . It provides effective data accumulation for realizing automatic constant pressure water supply.
