Research on Application of Energy-saving Motor in Power Plant

Energy-saving motor adopts new materials, new technology and optimized design to reduce the consumption of mechanical energy, electromagnetic energy and heat energy to achieve the purpose of improving output efficiency. Compared with ordinary motors, energy-saving motors can improve the efficiency by about 4%. Although this new type of motor has been on the market for a long time in China, the demand for it by Chinese people is relatively small. At present, the utilization rate of energy-saving motors in China is only below 20%. It can be seen that it is extremely critical and necessary to strengthen people's understanding of energy-saving motors. The application of energy-saving motors in power plants can significantly reduce the power consumption of power plants and improve the power efficiency.

1 overview of energy-saving motors

1.1 Operation principle of energy-saving motor

Compared with ordinary motors, the total consumption of energy-saving motors in the same time can be reduced by about 20%, and the saved electric energy is about 15%. The motor mainly consumes copper and iron in operation, but the energy-saving motor replaces the common iron core with new ferromagnetic materials in the selection of manufacturing materials, and at the same time, special off-line tools are selected to improve the slot full rate of the stator, thus increasing the cross-sectional area of copper wire. This not only effectively reduces the loss of iron and copper, but also significantly increases the manufacturing accuracy of the motor, and greatly reduces the stray power consumption. In addition, the manufacturing process and technology of energy-saving motors all adopt modern technology, among which high-quality electrical silicon steel sheets with high permeability and low loss are mainly selected to make their rotor cores and stator cores. As a result, the energy-saving motors have less loss, higher power factor, longer service life and high stability during operation. Meanwhile, new materials and technology manufacturing also reduce the area and volume of energy-saving motors.

1.2 characteristics of energy-saving motors

For the application of energy-saving motors, compared with ordinary motors, they have many advantages. First of all, when they are used in long-term power production, they can greatly reduce the required cost and save most of the energy, and they can be used in fans, water pumps, compressors, etc. Energy-saving motors can be started directly and the speed can be adjusted by frequency converter, and the power factor is mostly between 0.85 and 1.0, which can obviously improve the quality factor of the power grid, without the need of relevant power factor compensators. At the same time, the current generated by this kind of motor is relatively small, so it can obviously reduce the power consumption during transmission and distribution, and obviously prolong the service life. If the 55kW energy-saving motor is applied to power consumption, it can save about 15% of the power consumption compared with the ordinary motor, and the consumption cost of replacing the motor can be recovered within one year by calculating the 0.5 yuan per kWh.

1.3 Development Status of Energy-saving Motors

In our country, energy-saving motors are mainly promoted to small and medium-sized motor enterprises. In 1997, Kyoto Protocol of our country made new regulations on energy-saving motors in view of the fact that all countries in the world are facing the enormous pressure of energy saving and emission reduction. For our country, in

In 2011, China's national electricity consumption was 4,692.8 billion kilowatts. If the ordinary motor is replaced with an energy-saving motor, it can save about 4%, that is, 105.1 billion kilowatts of electricity, and at the same time, it can reduce the emissions of 310,000 tons of SO2 and 93.47 million tons of CO2. It can be seen that this regulation obviously reflects our country's emphasis on the improvement of motor efficiency, but for foreign energy-saving motors, its high cost is the main reason why small and medium-sized motor enterprises in China are reluctant to choose, which also requires relevant government departments in China to continuously strengthen their attention and support to China's motor manufacturing industry, so that China can establish the market competitiveness of the motor industry as soon as possible.

Motor products are mainly used in industrial production, so the development speed of the country in industry and other aspects directly determines the demand of motor products. At the same time, the problem of energy conservation and environmental protection has also attracted worldwide attention. All countries are looking for reasonable and effective power energy conservation measures, especially European and American countries [3], which have gradually applied energy-saving motors to various production. For individual developed countries, they have started to innovate and apply energy-saving motors that exceed the rate. According to the reference and analysis of relevant literatures in China, since 2012, most energy-saving motors have been produced in Asia and European countries, including South Korea, China, Japan and India in Asia and Britain, France and Germany in Europe. The productivity of these countries can account for about 69% of the world's survival rate, but since now, the production of energy-saving motors has gradually spread from developed countries to developing countries. In 2010, China issued the Implementation Details of Energy-saving Products Huimin Project Motor Promotion, which was accompanied by energy-saving subsidies. In April 2014, Huimin Project promoted low-voltage motors, high-voltage motors and permanent-magnet motors totaling more than 33 million kilowatts, and the motor market share was in

It reached 17.25% in 2013, but it is still far from the 50% share required by the State Council and the Ministry of Industry and Information Technology in 2015.

2 Main technical achievements of energy saving of motor system

For some problems existing in the energy saving of motor system in China, the related workers and managers in China have made great achievements during the 11th Five-Year Plan period with the support of a series of policies. First of all, for a series of motor systems with loads, such as pumps, compressors and fans, the corresponding system efficiency optimization measures and system management are adopted, so that the efficiency can be increased by more than 15%. At the same time, special variable frequency motors such as pumps and compressors, motors, control equipment, pumping units and special permanent magnet motors for textiles are also developed. For all kinds of energy efficiency testing and control systems in the motor system, electric and non-electric testing devices and energy efficiency testing devices of related systems are set up, and relevant energy-saving projects are implemented; In addition, the low-efficiency motor system and the obsolete motor system are comprehensively utilized, thus innovating the motor manufacturing technology level, increasing the efficiency of the original motor by 5%-30%, and establishing a fixed motor remanufacturing place to provide a foundation for its further improvement and manufacturing. At the same time, relevant departments have also strengthened the attention and management of energy-saving motors, one by one

Gradually promote the application and development of energy-saving motors into practice, and establish a promotion platform for energy-saving motor manufacturers in China, so that more power plants and other related enterprises can know about energy-saving motors and their functions.

3 Necessity of application of energy-saving motors in power plants in China

Nowadays, with the rapid development of various industrial industries in China, the rapid development of motors is guaranteed, but this situation will also lead to the contradiction between China's environmental resources and economic development. Therefore, while ensuring the continuous progress and development of China's economy, we should also ensure the conservation of resources and the protection and management of the environment, so as to ensure the sustainable development of China's economy and energy.

Although the use of motors in various enterprises in China has promoted the progress and development of China's industry and provided conditions for people's convenience in life, it has also greatly increased the consumption of electricity. After China put forward the relevant energy-saving policy management, the demand for energy-saving motors in China has increased. According to the survey and statistics of China's electricity consumption, 70% of the total electricity consumption of all electric power enterprises in China is caused by the load of motors on various equipment. Energy-saving motors can save energy by 3%-5% in normal operation, and the energy-saving efficiency of some energy-saving motors such as rare earth hydro-magnetic motors can be increased by more than 10%. Therefore, choosing energy-saving motors can effectively reduce energy consumption and environmental pollution. Nowadays, countries all over the world are constantly looking for effective measures to save energy and protect the environment. Therefore, the application of energy-saving motors is more and more extensive, which makes national standards promote industrial development.

4 Application Function and Conditions of Energy-saving Motors in Power Plants

4.1 Application of energy-saving motors in power plants

For China's power plants, they are mainly responsible for the power supply in China, and the work of each power plant in China is often fully automated. Therefore, motors are needed to drive their main equipment and machinery, so the required power consumption is huge. Nowadays, China's electric power industry is extremely competitive, which not only needs to ensure the lower cost, but also needs to obtain higher profits as much as possible. Therefore, it is a key task to constantly find effective measures to save energy and increase the rate.

For generators, the main economic and technical indicators include three items, namely, auxiliary power consumption, power supply coal consumption and power generation. These three economic and technical indicators are interrelated and influence each other. For example, if the influence index of power supply coal consumption in a power plant is 3.50%, the power consumption rate will increase by about 0.06% for every 1% decrease in its load rate. If the capacity of a unit is 1,000 MW, Under the working condition of rated running time and efficiency, the power consumption rate of the power plant is subject to 4.0%, and its power consumption can reach about 50.2 megawatts, and the annual power consumption is about 300 million kilowatt-hours. If energy-saving motors are used in the power plant to reduce the energy consumption by 5%, the annual power consumption can be saved by about 16 million kilowatt-hours. According to the average electricity price in China, that is, 0.5 yuan can save about 8 million yuan per kilowatt-hour. It can be seen that the energy saving of energy-saving motors in power plants is very obvious. It can be seen that if every power plant in China chooses energy-saving motors, it will not only significantly reduce the pollution to our environment, but also effectively save a large part of resources, and provide a favorable foundation for people's life and social development. However, because the cost of energy-saving motors is relatively higher than that of ordinary motors, choosing energy-saving motors in the initial investment of power plants will increase a certain initial investment cost. Some managers neglect sustainable development in order to save this investment. However, although the cost of energy-saving motors is about 15%-30% higher than that of ordinary motors, for the future development, the extra electricity saved will obviously reduce the required investment and increase the operating efficiency of power plants. Therefore, we must recognize the advantages of energy-saving motors before the initial bidding and putting into operation of power plants in China.

4.2 Application conditions of energy-saving motors in power plants

Many processes have been optimized. The common electric feed water pump is cancelled, and the original electric induced draft fan is replaced by pneumatic induced draft fan. However, some motors are used as compressors or fans, so it is necessary to judge and evaluate the efficiency and energy-saving mode selection according to the following points according to the operation characteristics of different power plants. First of all, the annual running time of the power plant should be evaluated. If the annual running time in the survey is more than 5,000 hours, and its load rate is more than 70%, the energy-saving motor should be selected. Assuming that the motor is 2,000 kilowatts, the energy-saving motor whose average efficiency can be increased by 1% can save more than 1 million kilowatts of electricity every year. Secondly, it depends on the power voltage of power plants. According to the investigation of related power plants in China, the water pumps and fans used in power plants in China mainly include powder exhaust fans, primary fans, induced fans, forced fans, boiler feed pumps, condensate pumps, mortar pumps and circulating pumps. The total motor capacity of the total set of equipment is 15,000 megawatts, and the annual total electricity consumption can reach 52 billion kWh, accounting for about 6% of the thermal power generation in China. In this case, adopting high-efficiency energy-saving motors can save about 40 billion kilowatt-hours of electricity every year, which can reach the annual power generation of eight thermal power plants with a capacity of about 1,000 megawatts. At the same time, the selection of auxiliary motors in the power plant mainly includes coal pulverizer, primary air blower and blower in charge of the air and smoke system, circulating water pump and condensate pump, etc. The electricity consumption of these high-power motors can reach about 65% of the total electricity consumption, which not only has large capacity but also consumes a lot of electricity. Therefore, these high-capacity and high-power motors should be used as energy-saving motors as much as possible. In addition, it is necessary to strengthen the use of energy-saving motors for the supporting equipment which plays a key role in the investigation, so as to improve the power supply efficiency and reliability. These supporting equipment which play a key role mainly include generator stator cooling water pump, mechanical vacuum pump, condensate pump, circulating water pump, main oil pump of the air conditioner, AC lubricating oil pump, primary fan, grinding fan and forced draft fan of the boiler system, various conveyors, HVAC air-conditioning chillers, instrument air compressor and ash remover of the material conveying system, etc.

5 Concluding remarks

Nowadays, with the development of China's electric power enterprises progressing and perfecting, how to reduce their energy consumption and improve their operating efficiency has become a key task. Relevant managers of each power plant should proceed from reality and choose energy-saving motor equipment according to the actual electricity consumption and situation, so as to provide favorable measures for reducing power consumption, increasing electricity generation rate and protecting the environment.