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Research on the application of high-efficiency and energy-saving motors in power plants

2019-10-14

High-efficiency and energy-saving motors use new materials, new processes and optimized designs to reduce the consumption of mechanical energy, electromagnetic energy and thermal energy to achieve the purpose of improving output efficiency. Compared with ordinary motors, high-efficiency and energy-saving motors can increase efficiency by about 4%. Although this new type of motor has been on the market in my country for a long time, the demand for it by Chinese citizens is relatively small. Today, the utilization rate of high-efficiency and energy-saving motors in our country is only less than 20%. It can be seen that it is necessary to strengthen people's awareness of high-efficiency and energy-saving motors. Understanding is extremely critical and necessary. The application of high-efficiency and energy-saving motors in power plants can significantly reduce the power consumption of power plants and improve the efficiency of electricity use.




1 Overview of high-efficiency and energy-saving motors




1.1 The operating principle of high-efficiency and energy-saving motors




The total power consumption of high-efficiency and energy-saving motors can be reduced by about 20% compared with ordinary motors in the same period of time, and the energy saved is about 15%. The motor mainly consumes copper and iron during operation. However, the high-efficiency and energy-saving motor uses new ferromagnetic materials to replace the ordinary iron core in the selection of manufacturing materials. At the same time, special offline tools are selected to increase the slot full rate of the stator so that the copper wire The increased cross-sectional area not only effectively reduces the loss of iron and copper, but also significantly increases the manufacturing accuracy of the motor, greatly reducing stray power consumption. In addition, the manufacturing process and technology of high-efficiency and energy-saving motors adopt modern technology. Among them, high-quality electrical silicon steel sheets with high magnetic permeability and low loss are mainly selected to make the rotor core and stator core, so that they are highly efficient. Energy-saving motors have smaller losses during operation, higher power factors, longer service times and high stability. At the same time, new materials and manufacturing processes have also reduced the area and volume of high-efficiency energy-saving motors.




1.2 Characteristics of high-efficiency and energy-saving motors




For the application of high-efficiency and energy-saving motors, they have many advantages compared to ordinary motors. First of all, when used in long-term power production, they can greatly reduce the required costs and save most of the energy. They can be used in fans and water pumps. , compressors, etc., high-efficiency and energy-saving motors can be started directly in applications and use frequency converters for speed adjustment, and the power factors are mostly between 0.85-1.0, which can significantly improve the quality factor of the power grid without the need for related power factor compensation. device. At the same time, the current generated by this type of motor is relatively small, so it can significantly reduce the power consumption during transmission and distribution, and significantly increase the service life. If a 55-kilowatt high-efficiency and energy-saving motor is used in electricity consumption, it can save about 15% of electricity compared with ordinary motors. % of electricity consumption, calculated at 0.5 yuan per kilowatt hour, the cost of replacing the motor can be recovered within one year.




1.3 Development status of high-efficiency and energy-saving motors




In our country, high-efficiency and energy-saving motors are mainly promoted in small and medium-sized motor enterprises. In my country's 1997 Kyoto Protocol, in view of the fact that countries around the world are facing huge pressure to save energy and reduce emissions, new regulations have been made for our country's high-efficiency and energy-saving motors. , for our country, in




In 2011, my country's national electricity consumption was 4,692.8 billion kilowatts. If the ordinary motor is replaced with a high-efficiency and energy-saving motor, about 4% can be saved. That is, 105.1 billion kilowatts of electricity can reduce approximately 310,000 tons of SO2 and 93.47 million tons of CO2. emissions. It can be seen that this regulation clearly reflects my country's emphasis on improving motor efficiency. However, the high cost of foreign high-efficiency and energy-saving motors is the main reason why my country's small and medium-sized motor companies are reluctant to choose them. This also requires my country's relevant Government departments continue to strengthen their attention and support for my country's motor manufacturing industry, so that our country can establish the market competitiveness of the motor industry as soon as possible.




Motor products are mainly used in industrial production. Therefore, the country's development speed in industry directly determines the demand for motor industry products. At the same time, the issue of energy conservation and environmental protection has also attracted worldwide attention. Every country is looking for reasonable and effective power. Energy-saving measures, especially in European and American countries [3], have gradually applied high-efficiency energy-saving motors to various productions. Some developed countries have begun to innovate and apply ultra-high-efficiency energy-saving motors. Through reference analysis of relevant literature in my country, since 2012, high-efficiency and energy-saving motors have been mostly produced in Asian and European countries. In Asia, they are mainly in countries such as South Korea, China, Japan, and India, and in Europe, they are mainly in countries such as the United Kingdom, France, and Germany. Productivity accounts for about 69% of the world's survival rate, but so far, the production of high-efficiency and energy-saving motors has gradually developed from developed countries to developing countries.In 2010, my country released the "Implementation Details of Energy-Saving Products Huimin Project to Promote High-efficiency Motors", which was followed by energy-saving subsidies. By April 2014, the Huimin Project had promoted low-voltage high-efficiency motors, high-voltage high-efficiency motors, and permanent magnet motors in total to more than 3,300 customers. Thousands of kilowatts, the market share of high-efficiency motors is in




It reached 17.25% in 2013, but there is still a big gap between the 50% share required by the State Council and the Ministry of Industry and Information Technology in 2015.




2 Main technical achievements in energy saving of motor systems




Regarding some problems existing in the energy conservation of my country's motor systems, relevant work and managers in my country have achieved great results with the support of investigations and research and the launch of a series of policies during the "Eleventh Five-Year Plan" period. First of all, efficiency optimization measures and system management of corresponding systems have been adopted for a series of load motor systems such as water pumps, compressors and fans, so that their efficiency can be increased by more than 15%; at the same time, water pumps and compressors have also been developed and other special frequency conversion motors, as well as high-efficiency motors, control equipment, pumping units and textile-specific permanent magnet motors, etc.; for various energy efficiency detection and control systems in the motor system, electrical and non-electrical testing devices have been set up, as well as energy efficiency detection of related systems. installation, and implemented relevant energy-saving projects; in addition, the low-efficiency motor system and the eliminated motor system were comprehensively utilized to innovate the high-efficiency manufacturing technology level of the motor, which can increase the efficiency of the original motor by 5%. -30%, and at the same time establish a fixed motor remanufacturing site to provide a basis for its further improvement and manufacturing.At the same time, relevant departments have also strengthened their emphasis on high-efficiency and energy-saving motors and their management efforts.




Gradually promote the application and development of high-efficiency energy-saving motors into practice, and establish a promotion platform for my country's high-efficiency energy-saving motor manufacturers so that more power plants and other related companies can understand high-efficiency energy-saving motors and their high-efficiency effects.




3 The necessity of applying high-efficiency and energy-saving motors in power plants in my country




Under the current situation of rapid development of various industrial industries in our country, the rapid development of motors has also been guaranteed. However, this situation will also cause conflicts between our country's environmental resources and economic development. Therefore, in order to ensure the continuous progress and development of our country's economy, At the same time, we must also ensure resource conservation and environmental protection and management to provide guarantee for the sustainable development of our country's economy and energy.




Although the use of motors in various enterprises in our country has promoted the progress and development of our country's industry and provided conditions for people's life convenience, it has also greatly increased the consumption of electricity. After our country proposed relevant energy-saving policy management, our country's demand for high-efficiency and energy-saving motors has increased. Surveys and statistics on electricity consumption in our country show that 70% of the total electricity consumption of various power companies in our country is generated by the load of the motors on each equipment. High-efficiency and energy-saving motors are used to complete energy-saving management to address this problem. Under normal operating conditions It can save energy between 3% and 5%, and the energy-saving efficiency of some high-efficiency energy-saving motors such as rare earth hydromagnetic motors can be increased by more than 10%. It can be seen that choosing high-efficiency and energy-saving motors can effectively reduce energy consumption and environmental pollution. Nowadays, countries around the world are constantly looking for effective measures to save energy and protect the environment. Therefore, the application of high-efficiency and energy-saving motors is becoming more and more widespread, allowing the standards of various countries to promote industrial development.




4 Application functions and conditions of high-efficiency and energy-saving motors in power plants




4.1 Application of high-efficiency and energy-saving motors in power plants




For our country's power plants, they are mainly responsible for the supply of electricity in our country, and the work of each power plant in our country is often fully automated, so motors are needed to drive their main equipment and machinery, so the required power The consumption is huge. Nowadays, my country's power industry is extremely competitive. It not only needs to keep the required costs low, but also obtains higher profits as much as possible. Therefore, it has become a more critical task to constantly look for effective energy-saving and efficiency-improving measures. .




For a generator, its main economic and technical indicators include three items, namely, power consumption, coal consumption for power supply, and power generation. These three economic and technical indicators are interrelated and influence each other, such as coal consumption for power supply in a power plant. The impact index is 3.50%. For every 1% decrease in the load factor, the power consumption rate will increase by about 0.06%. If the capacity of a unit is 1000 MW, the power consumption rate of the power plant under the rated operating time and efficiency working conditions is Based on 4.0%, the electricity usage can reach about 50.2 megawatts, and the annual electricity consumption is about 300 million kilowatt hours. If the use of high-efficiency energy-saving motors in the power plant can reduce energy consumption by 5%, then about It can save about 16 million kilowatt-hours of electricity consumption. Based on the average electricity price in China, which is 0.5 yuan per kilowatt-hour, it can save about 8 million yuan per year. It can be seen that the energy saving of using high-efficiency and energy-saving motors in power plants is extremely obvious. It can be seen that if every power plant in our country uses high-efficiency and energy-saving motors, it will not only significantly reduce the pollution to our country's environment, but also effectively save a large part of resources, providing a favorable foundation for people's lives and social development. However, since the cost of high-efficiency and energy-saving motors is relatively higher than that of ordinary motors, choosing high-efficiency and energy-saving motors in the initial investment in a power plant will increase the initial investment cost. Some managers ignore sustainable development in order to save this investment. , but although the cost of high-efficiency and energy-saving motors is about 15%-30% higher than the cost of ordinary motors, for future development, the amount of electricity saved will significantly reduce the required investment and increase the operating efficiency of the power plant. Therefore, in our country The advantages of high-efficiency and energy-saving motors must be recognized before the initial bidding and operation of the power plant, so as to provide a favorable foundation for the future energy-saving and efficient development of the power plant.




4.2 Application conditions of high-efficiency and energy-saving motors in power plants




Many processes have been optimized to a certain extent. Ordinary electric water supply pumps are cancelled, and pneumatic induced draft fans are used to replace the original electric induced draft fans. However, there are also some motors used as compressors or fans, which require different The operating characteristics of the power plant are used to judge and evaluate its efficiency and energy-saving method selection based on the following points. First, we need to evaluate the annual operating time of the power plant. If the annual operating time in the survey is more than 5,000 hours and the load rate is greater than 70%, then choose a high-efficiency energy-saving motor. Assuming that the motor is 2,000 kilowatts, choose the average efficiency High-efficiency energy-saving motors that can increase power by 1% can save more than one million kilowatts of electricity every year; secondly, it depends on the power voltage of the power plant. A survey of relevant power plants in China shows that the water pumps and fans used in power plants across the country mainly include The powder discharge fan, primary fan, induced draft fan, supply fan, boiler feed water pump, condensate water pump, mortar pump and circulating water pump, the total motor capacity of the complete set of equipment is 15,000 megawatts, and the total annual electricity consumption can reach 5 1.2 billion kilowatt hours, accounting for about 6% of China’s thermal power generation. In this case, the use of high-efficiency and energy-saving motors can save about 40 billion kilowatt-hours of electricity per year, which is equivalent to the annual power generation of eight thermal power plants with a capacity of one thousand megawatts. At the same time, the selection of auxiliary motors for the power plant mainly includes the coal grinder that functions as a pulverizer, the primary fan and blower responsible for the air and smoke system, the circulating water pump and the condensate pump that function as water supply and water microcirculation, etc. These large The power consumption of power motors can reach about 65% of the total power consumption. They not only have large capacity but also consume more power. Therefore, these large-capacity and large-power-consuming motors should be used as efficient and energy-saving motors as much as possible; in addition to In addition, it is necessary to strengthen the use of high-efficiency and energy-saving motors for supporting equipment that plays a key role in the investigation to improve power supply efficiency and reliability. These supporting equipment that plays a key role are mainly for cooling the stator of the generator in the gas turbine system. Water pumps, mechanical vacuum pumps, condensate water pumps, circulating water pumps, gas turbine main oil pumps, AC lubricating oil pumps in the gas turbine system, boiler system primary fans, grinding fans, air supply fans, various conveyors, HVAC air conditioning chillers, material transfer system instruments Air compressors and dust collectors, etc., can select appropriate high-efficiency and energy-saving motors for optimization based on their actual power and power consumption.




5Conclusion




Under the current situation of continuous progress and improvement in the development of my country's electric power enterprises, how to reduce their energy consumption and improve their operating efficiency has become a more critical task. The relevant managers of each power plant should proceed from reality and based on actual usage. Choose high-efficiency and energy-saving motor equipment based on electrical equipment and power consumption conditions to provide beneficial measures to reduce power consumption, increase power generation rate and protect the environment.


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