A cement company 2500 t/d production line supporting 4.5MW waste heat power generation system, condenser circulating cooling water through the cooling tower installed on the cooling tower fan ventilation cooling. After a long time of operation, the internal cooling fan drive and power part of the cooling tower will cause the cooling tower fan to vibrate more, affecting the safe operation of the fan, and there is a big potential safety hazard. Through the use of the our magnet motor transformation, eliminating the reducer and connecting the long shaft, to avoid vibration, to ensure the safe and stable operation of the system. Meanwhile, the energy saving effect is obvious after the use of permanent magnet motor.
Background
The motor of waste heat power generation cooling tower fan adopts asynchronous Y series motor, which is the equipment to be eliminated in the national high energy-consuming backward electromechanical equipments. The reducer and motor drive are connected by a long shaft of nearly 3m long, after a long time of operation, the wear and tear of the reducer and the drive shaft cause large vibration, which already affects the safe operation of the equipments, and it needs to be updated, but the overall cost of the whole set of replacement is higher than the cost of the PM motors, so it is proposed to modify the PM motor to avoid vibration. However, the overall replacement cost of the complete set is high, compared with permanent magnet motors, the cost difference is not significant, so it is proposed to replace the fan motor with a high-efficiency permanent magnet low-speed direct-drive motor, which has an obvious energy-saving effect in the industrial field.
Retrofit requirements and technical analysis
The original fan drive system is an asynchronous motor + drive shaft + reducer, which has the following technical defects: ① The drive process is complicated, with high process loss and low efficiency;
② There are 3 component failure points, increasing the workload of maintenance and overhaul;
③ The cost of specialized reducer parts and lubrication is high;
④No frequency conversion speed control, can not adjust the speed, resulting in a waste of electric energy.
High-efficiency permanent magnet low-speed direct drive method has the following advantages:
① High efficiency and energy saving;
② can directly meet the load speed and torque requirements;
③There is no reducer and drive shaft, so the mechanical failure rate is reduced and reliability is improved;
④ adopts frequency converter control, speed range 0~200 r/min. Therefore, the structure of driving equipment is changed to high-efficiency permanent magnet low-speed direct-drive motor, which can play the characteristics of low rotational speed and high torque, reduce the failure point of the equipment, and the maintenance cost and the difficulty of repairing are greatly reduced, and the loss is decreased. Through the modification of permanent magnet high efficiency low speed direct drive motor saves about 25% of electric energy and achieves the purpose of cost reduction and efficiency.
Retrofit program
According to the site conditions and site requirements, we design a high-efficiency permanent magnet low-speed direct-drive motor, install the motor and fan on site, and add a frequency converter control cabinet in the power room, so that the central control can automatically control the start-stop and adjust the rotational speed. The motor winding, bearing temperature and vibration measuring instruments are replaced on site and can be monitored by the central control room. The parameters of the old and new drive systems are shown in Table 1, and the photos of the site before and after the transformation are shown in Figure 1.
Figure 1
Original long shaft and gearbox construction Permanent magnet motor direct coupled fan
Effect
After the cooling fan system of the circulating tower of waste heat power generation is changed to permanent magnet direct-drive motor, the saving of electric energy reaches about 25%, when the fan speed is 173 r/min, the motor current is 42 A, compared with the motor current of 58 A before the modification, the power of each motor is reduced by 8 kW per day, and the two sets of them save 16 kW, and the running time is calculated as 270 d per year, and the annual saving cost is 16 kW×24 h×270 d×0.5 CNY/kWh=51.8 million Yuan. 0.5 yuan/kWh = 51,800 CNY. The total investment of the project is 250,000 CNY, due to the reduction of reducer, motor, drive shaft purchase cost of 120,000CNY, while reducing the loss of equipment downtime, the recovery cycle is (25-12) ÷ 5.18 = 2.51 (years). The old inefficient energy-consuming equipment is eliminated, and the equipment operates safely and smoothly, with obvious investment benefits and safe operation effects.
Introduction of MINGTENG
Anhui Mingteng Permanent-Magnetic Machinery& Electrical Equipment Co., Ltd(https://www.mingtengmotor.com/) is a high-tech enterprise integrating R&D, manufacturing, sales and service of permanent magnet motors.
The company is the director unit of “National Electromechanical Energy Efficiency Improvement Industry Alliance” and the vice president unit of “Motor and System Energy Saving Technology Innovation Industry Alliance”, and is responsible for drafting GB30253-2013 “Permanent Magnet Synchronous Motor Energy Efficiency Limit Value and Energy Efficiency Grade The company is responsible for drafting GB30253-2013 “Energy Efficiency Limit Value and Energy Efficiency Grade of Permanent Magnet Synchronous Motors”, JB/T 13297-2017 “Technical Conditions of TYE4 Series Three-phase Permanent Magnet Synchronous Motors (Block No. 80-355)”, JB/T 12681-2016 “Technical Conditions of TYCKK Series (IP44) High-efficiency and High-voltage Permanent Magnet Synchronous Motor” and other permanent magnet motors related national and industrial standards. The company was awarded the title of National Specialized and Specialized New Enterprise in 2023, and its products have passed the energy-saving certification of China Quality Certification Center, and have been shortlisted in the catalog of “Energy Efficiency Star” products of the Ministry of Industry and Information Technology of China and the list of the fifth batch of green design products in 2019 and 2021.
The company has always insisted on independent innovation, adhering to the “first-class products, first-class management, first-class service, first-class brand” corporate policy, to create a permanent magnet motor R & D and application of China’s influence on the innovation team, tailored for users of intelligent permanent magnet motor system energy-saving solutions, the company’s high-voltage, low-voltage, direct-drive, explosion-proof permanent magnet motor Our high, low-voltage, direct-drive and explosion-proof permanent magnet motors have been successfully operated on many loads such as fans, pumps, belt mills, ball mills, mixers, crushers, scrapers, oil pumping machines, spinning machines and other loads in different fields such as mining, steel and electric power etc.,achieved good energy-saving effects and gained wide acclaim.
Post time: Mar-28-2024