Advantages and applications of cast copper rotors in high-efficiency motor remanufacturing

Advantages and applications of cast copper rotors in high-efficiency motor remanufacturing

The 2017 Green Production and Consumption International Exchange Conference was held in Shangyu District, Shaoxing City, Zhejiang Province from November 9th to 10th. The exchange meeting was co-sponsored by the China National Institute of Standardization, the Academy of Science and Technology Strategy Consulting of the Chinese Academy of Sciences, and the China Industry-University-Research Cooperation Promotion Association. The conference focused on green production and consumption. At the same time, five sub-communication meetings were set up for green motors and electromechanical industries, green lighting, green building materials, green pharmaceuticals, and green design industries. In the green motor and electromechanical industry branch, the cast copper rotor motor became a hot topic discussed by the participating experts.

　　Bu Yi, deputy general manager of Yunnan Copper Die-casting Technology Co., Ltd., delivered a keynote speech on "Miniaturized Motor Technology Application and Standardization Progress" at the conference.

　　 He pointed out that electric motors are the most widely used power output source equipment in the world, and they are also the equipment group with the largest electrical energy consumption. Governments and international organizations around the world recognize that small and medium-sized motors have huge energy-saving potential. At present, the total electricity consumption of electric motors in China has accounted for more than 70% of the total industrial electricity consumption. Among them, small and medium-sized motors account for more than 70% of the motor market share, but the market share of small and medium-sized high-efficiency motors is only about 11%. If the efficiency of my country's existing small and medium-sized motors is increased by 2%, it will save up to 20 billion kilowatt-hours of electric energy consumption each year.

Advantages and applications of cast copper rotors in high-efficiency motor remanufacturing

　　 It can be seen from the above that the current energy-saving situation of electric motors in our country is severe, and improving the energy efficiency of electric motors is the only way to save energy.

　　Cast copper rotor technology is the most economical and simple solution among the industry-recognized high-efficiency motor technology solutions. Copper rotor motors have four major advantages:

　　 1. Improve efficiency. The replacement of aluminum rotors with cast copper rotors can significantly improve the efficiency of small and medium-sized motors, resulting in substantial energy savings. Taking the Y132M-4 7.5KW motor as an example, after replacing the cast copper rotor, the motor efficiency increased from 87% to 90.4%. Calculated based on the ten-year use of the motor, the electricity bill can be saved at 16,080 yuan, which is 16 times the replacement cost, and the benefits are very obvious. At present, Nanyang Explosion-proof Group has developed a copper rotor induction motor with IE5 efficiency level. The measured efficiency of the 15HP-4P motor can reach 93.6%.

　　 2. Reduce temperature rise. Taking a 25HP 18.7KW motor as an example, the temperature rise of a copper rotor motor is 41% lower than that of an aluminum rotor motor, which is only 47.2°C. And every time the operating temperature of the motor decreases by 10 degrees Celsius, the service life can be doubled. Therefore, the copper rotor motor can effectively extend the life of the motor. At the same time, it also increases electrical safety, especially suitable for explosive special environments.

　　3. Reduce volume, weight, and cost. Under the same efficiency, the volume of the cast copper rotor motor is about 15% smaller than that of the aluminum rotor motor, which is suitable for the application of reducing the base size of the motor, such as: reducer motor, compressor motor and pump motor. Through optimized design, the weight of the cast copper rotor motor can be reduced by about 20%. For example, the total weight of the 15 HP TEFC motor is reduced by 8KG after being converted to a cast copper rotor. In terms of cost, a cast copper rotor motor with the same efficiency can be reduced by about 10%. When the price of copper decreases or the price difference between copper and aluminum becomes smaller, the cost reduction will be more obvious.

　　 4. Corrosion resistance. Copper has excellent corrosion resistance, which makes the copper rotor very suitable for application scenarios such as brine pumps and hot water circulation pumps.

Mr. Bu also mentioned that the current "Energy Efficiency Limits and Energy Efficiency Grades for Small and Medium-sized Three-phase Asynchronous Motors" has made it clear that all motors of 0.75KW-375KW in the future must reach the level 3 energy efficiency index (IE2-high efficiency); among them, 7.5KW- The 375KW motor must reach the level 2 energy efficiency index (IE3-super high efficiency) in 2016; and the 0.75KW-7.5KW motor must reach the level 2 energy efficiency index in 2017.

　　With the continuous improvement of the energy efficiency of electric motors, the demand for high-efficiency electric motors will increase substantially in the future. The "Thirteenth Five-Year Development Plan for the Small and Medium-sized Motor Industry" also proposes: product miniaturization and light weight, using advanced technology and new high-quality materials, and focusing on the development of high power density and high reliability products. It can also be seen from this that copper rotors will inevitably become the development trend of high-efficiency induction motors. At present, Yuntong Die-casting Technology Co., Ltd. has built three production lines with an annual output of more than 150,000 cast copper rotors.

Advantages and applications of cast copper rotors in high-efficiency motor remanufacturing

　　In this meeting, Liu Wencan, deputy general manager of Yuntong Dongli Transmission Equipment Co., Ltd., also shared the advantages and application of cast copper rotors in high-efficiency motor remanufacturing. Motor remanufacturing refers to remanufacturing low-efficiency three-phase asynchronous motors into high-efficiency three-phase asynchronous motors, high-efficiency three-phase asynchronous motors for fans and pumps, and suitable for specific loads and working conditions through methods such as redesigning and replacing parts. System energy-saving motors, such as pole-changing motors, variable frequency motors and permanent magnet motors. Mr. Liu said that the cast copper rotor technology has obvious environmental and economic benefits in motor remanufacturing:

　　1. The high-efficiency remanufacturing technology of the cast copper rotors of the old motors is simple and feasible, which can effectively reduce resource and energy consumption, reduce waste discharge, and protect the environment; 　　2. It can not only save energy and reduce emissions, but also turn waste into treasure, prevent energy waste caused by re-recycling smelting and processing, and conform to the national industrial policy of comprehensive application of resource conservation;

　　3. The cost of replacing the copper rotor is much lower than the overall replacement of high-efficiency motors, which greatly shortens the project recovery cycle, which will significantly increase the enthusiasm of end users and greatly reduce the difficulty of promoting the efficiency of in-use motors;

　　4. The high-efficiency remanufacturing technology of cast copper rotors of stock old motors is one of the simplest, effective and economically feasible ways to solve the reuse of a large number of stock-used motors, maintain the existing technology, and improve the efficiency of the motors.

　　 When talking about the remanufacturing quality of cast copper rotor motors, Mr. Liu believes that advanced processing technology is the key guarantee for the electrical performance of the motor; intelligent equipment is the main guarantee for the mechanical performance of the motor. High-quality employees are a strong guarantee for high-quality remanufacturing processes. The motor remanufacturing process needs to strictly follow four principles:

Advantages and applications of cast copper rotors in high-efficiency motor remanufacturing

　　High quality: (Strictly abide by the remanufacturing process specifications, and do a good job of quality control in the remanufacturing process)

　　High efficiency: (improve efficiency, save costs, create more product value)

　　Energy saving: (to maximize the benefit of the remanufacturing process and achieve the purpose of energy saving and material saving)

　　Environmental protection: (Improve the utilization rate of old parts of the whole machine, reduce the number of replacement parts for new products, and at the same time improve the technical level in the remanufacturing process to reduce the emission of harmful substances)

　　At present, Yuntong Dongli Transmission Equipment Co., Ltd. can produce YZTE4 series of super-high efficiency cast copper rotor three-phase asynchronous motors that meet IE4 standards and YZTE3 series of super high-efficiency cast copper rotor three-phase asynchronous motors that meet IE3 standards. In the future, under the environment of developing a green economy, the high-efficiency remanufacturing market of cast copper rotor motors will have a broader development space.