(1) Technical scope of application

(1) Technical scope of application

This technology is mainly used for energy-saving technology in motors in various industries.

(2) Technical principles (transformation content)

① Technical introduction

There are two ways to save energy for water pumps and fans: one is soft start energy conservation, and the other is frequency conversion energy conservation. Since the motor starts for Y/D or directly, 4 to 7 times the rated current is the starting current, which will have a huge impact on the power supply grid and electromechanical equipment. If the power supply capacity is required very high, it will cause great damage during starting, such as valves and baffles being damaged by current and vibration, thereby shortening the service life of the equipment. After installing the frequency conversion energy-saving device, the soft start function of the frequency converter can automatically adjust the starting current at 6 o'clock to 0 at the beginning, so that there is no need to worry about the generated current exceeding the rated current, which reduces the impact on the power grid to a certain extent. It extends the service life of valves and equipment, thus saving costs related to the maintenance of the frequency converter.

② Energy saving principles

The design of traditional fans is designed based on maximum demand. The adjustment method is controlled by baffles, dampers, backflow, start-stop motors, etc., which cannot form closed-loop loop control and does not consider the concept of power saving. However, the flow rate in actual use varies with various factors (such as season, temperature, process, output, etc.) and is often much smaller than the maximum flow rate. When reducing the flow, usually only the opening of the baffle or valve can be adjusted, that is, the flow can be adjusted by closing the opening of the valve/baffle smaller and larger. The essence of the valve control method is to change the flow rate by changing the resistance of the pipe network. When the required flow rate is reduced in this control method, the pressure will increase, so the reduction of shaft power is limited. At this time, excess fan power will cause the pressure increase causes a large energy loss. It is known from the principles of fluid mechanics that flow is proportional to the first power of the speed, pressure is proportional to the square root of the speed, and power is proportional to the third power of the speed. The STB fan frequency conversion energy-saving control cabinet can adjust the flow by changing the speed of the fan while keeping the opening of the valve and baffle unchanged. The essence of this is to save electricity by reducing fluid power. This control method can fundamentally eliminate the power waste phenomenon of "big horse-drawn trolleys" that is common due to fan equipment selection or load changes, eliminate the throttle resistance of the baffle, and keep the fan running in the best working state.

(3) Application cases

Shanghai Huafeng Aluminum Co., Ltd. motor drive frequency conversion control energy-saving technology.

1) Implementation content and cycle: Before the project transformation, the company's general equipment such as fans and water pumps adjusted the load of the equipment through valve control and adjustment methods. During this operation process, due to the inability of manual control in real time, the equipment energy consumption during some time was high or low. A frequency conversion control system is now added to this type of motor. By adjusting the speed of the motor, the flow rate of the water pump or fan, the operating efficiency of the process equipment, etc., and the implementation period is unknown.

2) Energy conservation and emission reduction effect and investment payback period: Before the transformation, the production workshop consumed 78063035.88kWh of electricity, produced 86239042.58kg of qualified products, and the power consumption per unit product in the base period before the transformation was 905.19kWh/t; During the reporting period, the production workshop consumed 64093180.45kWh of electricity, produced 94382132kg of qualified products, and the power consumption per unit product in the base period before the transformation was 679.08kWh/t. Partial energy saving amount of power (unit consumption of product in the base period-unit consumption of product in the reporting period) × output in the base period × conversion factor =(905.19kWh/t-679.08kWh/t) ×86239.04t×2.88 tons of standard coal/10,000 kWh= 5,615.91 tons of standard coal; the payback period is 0.7 years.

(4) Potential for replication and promotion, energy-saving potential (payback period)

The technology is applied to all walks of life, used for energy-saving technical transformation, the technical transformation method is safe and reliable, can effectively improve the original defects of the existing motor, has greater energy-saving potential, obvious energy-saving emission reduction effect, broad application prospect and greater replication potential.