Energy-saving analysis of frequency conversion speed regulation technology in fan and pump applications

- Jan 07, 2019-

I. Introduction

In industrial production and product processing manufacturing, wind turbines and pump equipment are widely used; their power consumption and throttling losses such as valves and baffle-related equipment, as well as maintenance and repair costs account for 7% to 25% of production costs. It is not a small production expense. With the deepening of economic reforms, market competition has intensified; energy conservation and consumption reduction has become one of the important means to reduce production costs and improve product quality.

         The frequency conversion speed regulation technology developed in the early 1980s is in line with the requirements of the development of industrial production automation, creating a new era of intelligent motors. The old mode that the ordinary motor can only run at a fixed speed mode can make the motor and its drag load adjust the speed output according to the production process requirements without any modification, thereby reducing the power consumption of the motor and achieving the purpose of efficient operation of the system. .

       In the late 1980s, the technology was introduced to China and promoted. It has been applied in motor drive equipment in various industries such as power, metallurgy, petroleum, chemical, paper, food, textile and so on. At present, frequency conversion speed control technology has become a major development direction of modern electric drive technology. Excellent speed regulation performance, remarkable power saving effect, improvement of operating conditions of existing equipment, improvement of system safety and reliability, equipment utilization, and extension of equipment service life, etc., with the continuous expansion of application fields reflect.

         Second, the review

       Generally, in industrial production and product processing manufacturing, fan equipment is mainly used in boiler combustion systems, drying systems, cooling systems, ventilation systems, etc., according to production needs, the furnace pressure, wind speed, air volume, temperature and other indicators are controlled and adjusted. Adapt to process requirements and operating conditions. The common control method of Zui is to adjust the size of the damper and the opening of the baffle to adjust the controlled object. In this way, regardless of the demand for production, the fan must run at full speed, and the change of operating conditions causes the energy to be consumed by the throttling loss of the damper and the baffle. In the production process, not only the control accuracy is limited, but also a large amount of energy waste and equipment loss. As a result, the production cost increases, the service life of the equipment is shortened, and the equipment maintenance and maintenance costs are high.

         Pump equipment also has a wide application space in the production field. Pumping stations, pool storage tanks, industrial water (oil) circulation systems, and heat exchange systems use centrifugal pumps, axial pumps, gear pumps, and plungers. Pumps and other equipment. Moreover, according to different production requirements, control devices such as regulating valves, return valves, and shut-off valves are often used to control the flow, pressure, water level and other signals. In this way, not only a large amount of energy is wasted, but also the sealing performance of pipelines and valves is destroyed; the wear and cavitation of the pump chamber and the valve body are accelerated, and the equipment is seriously damaged, the production is affected, and the product quality is endangered.

Fans and pumps are mostly driven by asynchronous motors, which have shortcomings such as large starting current, mechanical shock, and poor electrical protection. It not only affects the service life of the equipment, but also does not instantaneously protect the equipment when there is a mechanical failure in the load. The pump is often damaged and the motor is burned.

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