With the construction of large-scale infrastructure and the rapid development of social economy, the construction of large and medium-sized cement plants is becoming more and more perfect, and the task of energy conservation and emission reduction is quite heavy. In the power plant of the cement plant, small and medium-sized motors occupy a dominant position, and the annual energy consumption accounts for more than half of the power loss of the entire cement plant. In order to further implement the national energy conservation and emission reduction policies and achieve energy conservation and emission reduction targets, energy conservation of small and medium-sized motors is a major issue facing the cement industry and a new opportunity for the development of the cement industry. 1. Domestic motor and energy saving status 1.1 Status At present, China's small and medium-sized motors have three series of three-phase asynchronous motors: Y, Y2 and Y3. At present, most of the motors equipped in the process equipment of cement plants are such asynchronous motors. In 1985, the Y series three-phase asynchronous motor and its derivative series products were vigorously promoted, with power ranging from 0.55 kW to 250 kW. After the introduction and digestion of the technology of Westinghouse and Swiss BBC, the Y series 6kV medium-sized high-voltage three was developed. Phase asynchronous motor, power range from 220kW to 2800kW. With the advancement of China's power technology, the grid voltage has risen from 6kV to 10kV, and 10kV series high-voltage asynchronous motors have been developed successively, and adopting novel box-type structure, such high-voltage motors are currently It occupies a dominant position in the domestic medium and high voltage motor market. In 1996, China developed the Y2 series three-phase asynchronous motor with power ranging from 0.12 kW to 315 kW. This series of motors not only greatly reduced the no-load noise, but also effectively suppressed the load noise. In 2003, Y3 series three-phase asynchronous motors were launched one after another. These motors were formed by cold-rolled silicon steel sheets, and their energy consumption has reached the limit of energy consumption in GB18163-2002 "Energy efficiency limit value and energy-saving rating of small and medium-sized three-phase asynchronous motors". Relevant regulations, its main performance indicators have also reached the current international advanced level. 1.2 The configuration and energy saving status of the motor in the cement plant Regardless of the size of the equipment, the cement plant uses motor drag, 90% of which are AC asynchronous motors, and about 50% are high-voltage motors. About 70% of them are driven by fans and other loads, and such loads are very large. Some need speed regulation. At present, in the traditional cement plant, the most widely used method of adjusting the air volume is to use an electric actuator to adjust the wind deflector, and adjust the opening of the wind deflector to adjust the required air volume. In the process of adjusting the windshield, the rotation speed of the motor remains unchanged, and the output energy is also unchanged. Only by adjusting the opening degree of the windshield to achieve the required air volume requirement of the load. According to the law of conservation of energy, when the load requires a small amount of air according to the requirements of the system, the opening of the wind deflector is reduced. At this time, the difference between the output energy of the motor and the energy required by the load is It is consumed and lost in vain. In addition, the damper adjustment of the cement plant is mostly realized by electric regulating valve. The quality of the electric regulating valve determines the flexibility of the damper switch. Since the cement plant is a dusty enterprise, even if environmental protection equipment is used at each dusting point, the cement plant has tried to adopt a series of dust collection measures, and it is difficult to avoid the emission of fine dust. During use, many windshields are not affected by the environment, and cannot be flexibly opened and closed according to the instructions given above. Even some gates are stuck by materials during use, which makes them impossible to adjust, such as those commonly used in production. The top material material distribution valve, the workers often go to the inspection and on-site cleaning, not only time-consuming and laborious, but also bring great losses to the production, and this is also a major hidden danger in the production process, more importantly, the energy loss is serious. In addition, the resistance loss caused by the use of the gate control valve seriously affects the economic operation of the equipment, and it is imperative to improve this adjustment mode. 2. Development trend of motor energy saving In the “Energy Conservation and Environmental Protection Industry Development Plan†issued by the state, the use of high-efficiency energy-saving technology and the adoption of energy-efficient equipment are an important part. The use of variable frequency speed regulation and the use of energy efficient motors are two important ways to improve the efficiency of motor operation. 2.1 Energy saving through variable frequency speed regulation In actual operation, the air volume required by the system will change with the change of working conditions and output. Since the inverter can adjust the motor speed in real time according to actual needs, the motor can be operated at the most energy-saving speed, reducing the light load operation. The power consumption, wide speed range, high adjustment precision, high operating efficiency, and can achieve soft start of the motor, reduce the starting impact and equipment wear, reduce the overall power consumption of the motor operation, this energy-saving method has obvious energy-saving effect, general section The electricity rate is 20%~30%, sometimes even 50%, and the most important thing is: the investment recovery period is short, and the full investment can be recovered soon. At present, the low-voltage frequency conversion technology is becoming more and more mature, and the product quality is also relatively stable. In the newly built large and medium-sized cement plants, the low-voltage motors that need to be adjusted for air volume have basically adopted the AC frequency converter to adjust the speed, change the required air volume, and improve the operating efficiency. The motor speed is effectively controlled to achieve energy saving of the motor, such as the chiller cooling fan of the kiln clinker conveying part, the kiln head primary fan, the circulating water pump and some dust collecting fans. China's high-voltage motors are mostly 10kV. Due to the voltage withstand voltage limitations of power electronics, it is still difficult to achieve direct high-voltage output of this class of inverters. At present, domestic high-voltage inverters adopt unit-series multi-level inverter technology, and its output voltage can reach 10kV or higher, and the input and output waveforms are good, and the harmonic pollution to the power grid is small. Foreign high-voltage inverter technology is mature, but its price is 2~4 times of the price of domestic high-voltage inverter. In the case that many cement plants in China are not very abundant, domestic inverters have been widely used due to low price. However, there are also very few cement plants that are subject to funding restrictions. At present, there is little or no use of high-voltage variable frequency speed regulation, and the energy-saving effect is not obvious. Driven by the national energy-saving environment, the dynamic load of 10kV dragging is imperative for high-voltage motors to adopt high-voltage variable frequency speed control. In the process of designing foreign cement plants, the situation will be much better. Due to sufficient funds, new foreign cement plants, in addition to the low-voltage motor and kiln high-temperature fan that need speed regulation, use variable frequency speed regulation, other high-voltage motors that need speed regulation have basically adopted high-voltage frequency conversion speed regulation, and most of them are famous abroad. The high-voltage frequency conversion complete sets of brands (such as ABB), such as raw material circulation fan, kiln tail rear exhaust fan, kiln head residual air fan, cement mill dust collecting fan, etc., have significant energy saving effects. As a new type of speed control method, the variable frequency speed control method has superior performance, high cost performance and obvious energy saving effect. It is a kind of energy saving control method widely used in domestic large and medium cement plants. The frequency conversion speed regulation energy saving sums up three major advantages in practical application: one is to reduce power loss, reduce cost and save energy; the second is to broaden the speed regulation range of the system and improve the flexibility of the system operation; the third is to change the motor's The start-up mode truly realizes the soft start of the motor, greatly reducing the wear and tear on the motor, fan, damper and other equipment, and starting the impact on the power grid, prolonging their service life and greatly saving the maintenance cost of these equipment. The most effective one for speed control and energy saving control. 2.2 Using high efficiency motors to achieve energy savings From the perspective of energy conservation and environmental protection, high-efficiency electric motors are not only cement plants but also all domestic industrial development trends. Among the country's six major power-consuming industries, the cement industry is among them, and it is also the main application area for small and medium-sized motors. The greater the energy consumption, the higher the potential for energy conservation. Under normal circumstances, the main production workshops of the cement plant (raw mill, rotary kiln and cement mill) are mostly 24h continuous working system, long working time and relatively stable working load. These features are beneficial to high efficiency motors. Promotion and use of cement plants. According to GB18613-2006 "Energy efficiency limit value and energy efficiency rating of small and medium-sized three-phase asynchronous motor", China's motor energy efficiency is divided into three levels, energy efficiency level is ultra-efficient motor, energy efficiency level 2 is high-efficiency motor, energy efficiency level is ordinary motor. The high-efficiency motor process is optimized by design and is made of high-quality materials, and its energy consumption can be reduced by about 20% on average. The ultra-efficient motor energy consumption is more than 30% energy-saving than ordinary motor energy, and can save energy for the enterprise throughout the production cycle. Although the price is between 15% and 30% higher than that of an ordinary motor, in general, a one-time investment higher than that of an ordinary motor can be fully recovered within one to three years. Therefore, the selection of high-quality and energy-efficient motors in cement plants with long-term continuous operation and high load rate is in line with China's energy-saving policy, and it is very necessary and practical to consider both the survival and development of enterprises. 2.3 Reasonable choice of motor power Due to historical reasons, in practical applications, there are a large number of motors that drive the load power much less than the power of the motor itself, resulting in a large number of motors in an inefficient operating state. For example, fans with a large amount of electricity, pumps, and compressors have an average system operating efficiency of about 50%. In the design and selection, in order to ensure sufficient power, the designer adds the margin and the level of insurance, which is easy to cause the state of the big horse-drawn car, and its efficiency is low. Even some users mainly use the frequency converter to adjust the speed, so that the motor is in low frequency and inefficient operation for a long time, which is also a phenomenon of large horse-drawn cars. As we all know, the optimal operating efficiency of the motor generally occurs between 0.7 and 0.85. The too high and too low load rate will not only reduce the efficiency of the motor, but also cause great damage to the motor itself. Maintenance costs and maintenance costs. In the load calculation of a certain cement plant, according to the motor power of the process, the theoretical calculation of the load factor of the optional transformer is about 0.75, and the load rate can only be below 0.6 in actual operation. The phenomenon of big horse-drawn cars not only wastes equipment resources, but also wastes valuable electricity. Especially in the current situation of insufficient or even shortage of funds in some cement plants, it has caused great capital and survival pressure for enterprises, and the enterprises have also lost valuable opportunities for redevelopment. In the design process, the reasonable selection of the power of the motor not only conforms to the national energy conservation policy, but also reduces the financial pressure of the enterprise. More importantly, it creates a good economic foundation and development environment for the company's future survival and development, and reasonable matching. The power of the motor required for the load is a long way to go. 3, the conclusion Promote advanced motor speed control technology such as frequency conversion speed regulation, improve the adjustment mode of motor system, and gradually eliminate mechanical throttle adjustment methods such as gates and valves. Focus on the transformation of the traditional cement plant motor, select the appropriate speed control mode; rationally select the motor to make the motor run in the best efficiency state; when designing or rebuilding the cement plant, carefully calculate the power and strive to achieve the motor power and load. The best match, gradually eliminate or reduce the phenomenon of large horses and carts; design and selection of high-efficiency energy-saving motor to drag the load, to fundamentally achieve the real energy saving of the motor. Concerned about surprises Label: domestic electromechanical energy saving status development trend Previous: Selection of motor protector Next: Application of linear motor on high speed machine
bergamot oil, cedarwood oil, Chamomile Oil, Jasmine Oil , Lavender Oil , mandarin oil, Marjoram Oil, Rosemary Oil , sage oil, valerian oil, vetiver oil, Ylang Ylang Oil
Sleep Essential Oil Marjoram Oil,Sleep Essential Oil,Lavender Oil,Rosemary Oil Jiangxi Global Natural Spice Co., Ltd. , https://www.chessentialoil.com