Energy saving benefits of high voltage frequency c

Energy is the material basis of economic development, but also an important constraint to economic and social science and sustainable development. As the second largest energy consumer in the world, China has always attached great importance to energy and energy conservation. As early as the early 1980s, China put forward the policy of "paying equal attention to energy development and conservation, and giving priority to conservation", and incorporated energy conservation into the national economic and social development plan. At present, China's economy is growing rapidly, and the contradiction of energy shortage is increasingly apparent. Its characteristics are: first, the per capita energy is relatively insufficient. The per capita share of most energy resources in China is less than half of the world average. 2、 Low energy efficiency. China's energy consumption per million US dollars of GDP is 2.4 times higher than the world advanced level, and its energy efficiency is 10 percentage points lower than the international advanced level. 3、 The contradiction of energy constraints is prominent. In recent years, bottlenecks in coal, electricity, oil and transportation have reappeared. 4、 Environmental pollution is serious. China is a small number of countries with coal as the main energy, and it is also the largest coal consumer in the world. Energy use should be as small as possible; Fine polishing after finishing (or the purpose is to eliminate the huge environmental pressure caused by the surface damage caused by rough polishing.

in order to speed up the construction of an energy-saving society, alleviate the current tension in coal, electricity and oil transportation, and the resource constraints and environmental pressure faced by the majority of people who adopt utm7504 z03 ring stiffness experimental plane to build a well-off society, so as to ensure the sustained, rapid, coordinated and healthy development of the national economy, every power generation company and power plant should fully recognize their own society and save Energy, improving energy efficiency and reducing environmental pollution are the internal driving forces for the sustainable and healthy development of enterprises

energy conservation aims to reduce the energy consumption per unit output value for the macro, and to reduce the unit consumption of products for the industry

at the end of 2001, in order to further implement the requirements of the leaders of Datang International power generation company to "focus on reducing the auxiliary power consumption rate with the goal of ensuring safe production, improving the health level of equipment and improving economic benefits", the company decided to change the frequency of high-voltage auxiliary equipment of some power plants as a key measure of energy conservation in 2002

the relevant professionals of the company are slow in temperature drop and the minimum possible loading force is 0.91kn. They have been learning about the relevant data of high-voltage frequency converter since 1999 and paying attention to the relevant situation of high-voltage frequency converter that has been put into operation. In order to further understand the use and maintenance of the frequency converter and the production status of domestic manufacturers, the frequency converter research team of the company conducted a survey on some power plants and manufacturers in early 2002, conducted an in-depth and detailed discussion on the operation, technology, benefits and other related issues, and carried out a detailed economic benefit calculation of the project. After careful comparison and accounting, the bidding was carried out. So far, the company has put 42 high-voltage frequency conversion devices into operation, and the economic benefits are also obvious. The following is a detailed comparative analysis of the economic benefits after the transformation of various high-voltage frequency conversion devices of different capacity units:

I. economic benefit comparison:

high voltage frequency conversion devices are distributed on the company's 100-600mW units, mainly including primary air fans, forced draft fans, suction fans, condensate pumps, etc. The detailed comparison of economic benefits is as follows:

1 Zhangjiakou Power Plant #8 boiler (300MW Unit) primary air fan

the pulverizing system of Zhangjiakou Power Plant #8 boiler is a positive pressure direct blowing system of medium speed mill cooling primary air fan, equipped with 6 zgm95g medium speed coal mills. The forced draft fan and suction fan are movable blade adjustable fans produced by Shanghai blower factory

since the models of the primary air fans of #7 and 8 units are the same, but the #7 boiler was not equipped with frequency conversion at the time of the test, through the comparative test with #7 boiler, the power of #8 boiler's primary air fan was 1127 kW, 946 kW, 689 kW and 809kw lower than #7 boiler under the conditions of 150MW, 200MW, 250MW and 300MW respectively. According to the analysis of unit operation in 2001, taking the average load of the unit as 200 MW, the annual operation hours of the unit as 7200 hours, and the upper electricity price as 0.3 yuan/kW · h, the annual power saving of #8 boiler primary fan is 6.66 million kwh, and the power saving benefit is 2 million yuan, especially under low load conditions, the energy-saving effect is more obvious. The price of the two high-voltage converters is 5.6 million yuan, and the full cost can be recovered in less than three years, and its investment benefit ratio is relatively good

2. The suction fan of #2 boiler (100MW unit) in Xiahuayuan Power Plant

the type of suction fan of #2 boiler in Xiahuayuan Power Plant is Y-type, and the motor power is 550 kW. The test of the unit under different loads shows that when the unit load is 50MW, 70mW, 85mW and 100 MW, the frequency conversion speed regulation of the two suction fan systems reduces the comprehensive input power by 471 kW, 506 kW, 472 kW and 428 kW respectively compared with the baffle regulation. Considering the 6500 hours of annual operation of the unit, the annual power saving is 3.14 million kwh, the direct economic benefit of power saving is 880000 yuan, and the investment payback period is 3.6 years. Mainly due to the small capacity of the motor and the relatively high price of the frequency converter, the investment payback period is relatively long

3. Zhangjiakou Power Plant #6 unit (300MW Unit) condensate pump

after the condensate pump of Zhangjiakou Power Plant #6 unit changed frequency, the actual power consumption of constant speed throttling regulation and frequency conversion regulation obtained from the test was compared. Based on the average operation of 7000 hours, the annual power saving benefit was about 4.08 million kwh. After deducting the power consumption of air conditioning, the annual power saving was 4.05 million kwh. Based on the calculation of 0.3 yuan/kW · h yuan of power supply, the annual economic benefit was 1.25 million yuan, The full cost can be recovered in less than 3 years. At present, the condensate pumps of Zhangjiakou Power Plant 5, 6, 7, 8 units are changed to frequency conversion

4. Douhe Power Plant #2 unit (125MW Unit) suction fan

Douhe Power Plant #2 unit suction fan motor capacity is 1000 kW, which was put into operation after minor modification in November 2002. In the test, when the unit load is 90mw, 100MW, 110MW and 125 MW, the frequency conversion speed regulation of the two suction fan systems reduces the comprehensive input power by 571 kW, 472 kW, 489 kW and 520 kW respectively compared with the baffle regulation. The unit is a peak shaving unit, which often operates in a two shift system. Based on the annual operation of 5500 hours of the unit, about 2.64 million KW h of electricity is saved every year, the direct economic benefit is about 860000 yuan, and the investment payback period is about 2.8 years

5. During the overhaul of 3 unit (250MW unit) suction fan of Douhe Power Plant in October, 2002, the frequency of 3 unit suction fan was changed. Through the test, when the unit load is 126mw, 150MW, 175mw, 200MW, 225MW and 250MW, the frequency conversion speed regulation of the two suction fan systems reduces the comprehensive input power by 1048 kW, 1062kw, 1052 kW, 872kw, 694kw and 520 kW respectively compared with the damper regulation. Based on the current operating load of the unit, about 6million kwh of electricity is saved every year, and the direct economic benefit is about 160-170