Energy-saving Application Effect of Frequency Converter in Thermal Power Enterprise

With the continuous advancement and refinement of frequency conversion technology, its remarkable energy-saving performance, excellent starting characteristics, and comprehensive protection functions have been widely adopted in enterprises. This has enabled companies to reduce energy consumption, lower operational costs, and improve overall system efficiency (ASD). 1. **Characteristics of the Inverter** Frequency control is currently the most advanced and promising method for speed regulation. Inverters are the primary devices used for adjusting the speed of three-phase asynchronous motors in industrialized nations. Their key advantages include a significant energy-saving effect, with potential savings of up to 55%. They offer a wide speed range, with a ratio of up to 20:1. The inverter provides smooth start-up and braking, enabling soft starts, automatic acceleration and deceleration, and rapid braking. It also features robust protection functions, such as overvoltage, undervoltage, overload, overcurrent, power failure, short circuit, and stall protection, allowing for fault detection and display. Additionally, inverters can be easily integrated into computer systems and support long-distance control. 2. **Application of Frequency Control Technology in Cogeneration Systems** 2.1 **Central Heat Exchange Station and External Network Control** The boiler system typically includes constant pressure water supply, hot water circulation, combustion control, and furnace pressure regulation. In cogeneration systems, superheated steam produced by the boiler can be directly output or exchanged through steam and water before being exported. The heat from the steam or hot water is delivered to users via various heat exchange stations throughout the network. 2.2 **External Network Circulation Pump Control** Maintaining stable pressure in the heating system is essential for normal operation. The heating network is usually a closed-loop system, where theoretically, water loss is minimal. However, in practice, factors like leakage, blowdown, and manual water use can affect system stability. Temperature changes in the flow also influence pressure. To ensure consistent heat supply, the system must remain fully filled at the highest point, and the pressure must not exceed the system's capacity. A constant pressure point on the return line is established to maintain stable pressure during circulation, limiting pump flow and head within certain ranges. This allows for automatic adjustment of flow and head, helping to prevent overheating and overpressure in the boiler system. A constant-pressure replenishing pump adjusts the pump speed based on pressure sensor feedback, ensuring steady water levels. In the heating system, water acts as the thermal carrier, transferring heat through its flow. Higher water temperatures mean more heat per unit volume, and greater flow means more heat delivered. Using frequency conversion speed control helps regulate the circulation pump’s flow under stable pressure conditions, ensuring safe operation of the heating system. By following guidelines such as low-temperature operation and small temperature differences, the system adjusts water temperature based on ambient conditions and controls the circulation pump speed using return water temperature differences to indirectly regulate temperature. 2.3 **Control of Induced Draft Fan High-Voltage Frequency Conversion** High-voltage frequency converters are series-connected systems that use multiple single-phase three-level inverters to generate high-voltage AC. According to electrical machinery principles, motor speed is proportional to the operating frequency. Adjusting the frequency allows for precise motor speed control. The converter consists of a transformer cabinet, power cabinet, and control cabinet. Input voltage is stepped down and phase-shifted before being distributed to each power unit. The control unit uses optical fibers to monitor and adjust each unit, sending commands based on actual needs. On the output side, units are connected in series using a star configuration to supply power to the motor. The resulting staircase PWM waveform reduces insulation stress on cables and motors, eliminates harmonic losses, and minimizes mechanical vibrations. This makes the system ideal for retrofitting old equipment without requiring derating. 2.3.1 **Inverter Operation and Startup** There are three operation modes: local control via the touch screen, remote control via a controller, and DCS integration for full process control. Three startup methods include normal start, soft start, and bypass operation in case of failure. The bypass function allows direct motor operation when the inverter is not working, facilitating maintenance. 2.3.2 **Energy-Saving Analysis After Frequency Conversion** In Tianjin, all coal-fired boilers must have desulfurization and dust removal systems, which increase resistance and motor power requirements. Traditional damper control is inefficient and energy-intensive, while inverter control optimizes fan speed based on load, reducing energy use and meeting emission standards. For example, a 315kW induced draft fan can save approximately 544,320 kWh annually, leading to significant cost savings. 2.4 **Inverter in Water Level Regulation** When drum water level changes, the transmitter sends a signal that is compared with a setpoint to generate a deviation signal. The regulator processes this signal and sends it to the inverter, which adjusts the pump motor frequency to change the flow rate and stabilize the drum level. 3. Variable frequency speed control technology is becoming increasingly widespread across industries. Its energy-saving benefits and compatibility with automated systems make it a central component in modern power drive systems. Furthermore, the application of frequency control technology is an effective way for companies to enhance efficiency and boost profitability.

Special Shape Fabric Air Duct

Special Shape Fabric Air Duct,Ventilation Duct Machine,Fiberglass Air Duct Fabric,Insulated Fabric Duct

Jiangsu Buna Technology Development Co. , Ltd. , https://www.ductbuna.com