Weak current College】 【inverter technology in application of parsed --- energy saving Power By】 【China power house network.

<br> I. introduction <br> <br> In industrial production and product manufacturing, fans, pumps is wide; its energy consumption and such as valves, bezel of throttling losses associated equipment as well as maintenance and repair costs to the production cost .of 7% to 25%, is a small production expenses. With the deepening of economic reforms, increasing competition in the market; energy consumption has become a lower production costs, improve product quality in one of the important means. But in the early 1980s ., developed inverter, precisely the industrial production automation development requirements, ushered in a new age of intelligent machines. Changed the ordinary motor can only run in constant speed of stale mode, making motor and drag the load without any change of circumstances that can follow the .production process for adjustment of the speed of output, thereby reducing motor power to the system running efficiently. In the late 1980s, the technology into our country and get promoted. Now in the electric power, metallurgy, petroleum, chemical industry, papermaking, food ., textile and other industries of electric transmission equipment in the actual application. At present, the inverter has become a modern power transmission technology, one of the main directions of development. Excellent conversion performance, significant energy saving effects and improve existing equipment operating conditions, .improve system reliability and safety of the equipment utilization, extend equipment life and other advantages as field of application is expanding. <br> <br> II. Summary <br> <br> Usually in industrial production, product processing and manufacturing equipment mainly used .in fan combustion system, drying system, cooling system, ventilation system, etc, depending on production requirements the furnace pressure, wind speed, air flow, temperature, and other indicators for control and regulation in order to adapt to the technological requirements and operating conditions .. The most common means of control is adjustable throttle, bezel opening size to adjust the managed object. In this way, regardless of the size of the production demand, fan to speed and operating changes you made to air door, bezel of energy saving loss .consumed. In the production process, not only control accuracy is limited, but also caused a lot of energy to waste and equipment loss. Resulting in increased production costs, shorten equipment life, equipment maintenance, high maintenance costs. Pump equipment in production areas also .has broad application space, pump stations, water storage tank for water drainage system, industrial (oil) circulatory system, heat systems use centrifugal pump, axial-flow pumps, gear pumps, piston pumps and other equipment. Also, depending on production requirements are .often adjust valves, return valves, globe valves, throttle devices for flow, pressure, water level and signal control. In this way, not only cause a lot of energy, waste, pipelines, valves etc airproof performance; also speeded up the pump, .valve wear and cavitation, serious damage to the device, affect production, endanger the quality of products. Ventilator and pump equipment most used asynchronous motor direct drive way, start current, mechanical shock, electrical protection of poor shortcomings. Not only affects the service life .of the device, and when the load has a mechanical failure not protecting device, instant action often pump damage at the motor also burned for phenomena. In recent years, the urgent need for energy saving and product quality requirements, coupled with a frequency converter ( .inverter), easy operation, maintenance, control, high precision, and can achieve high functional features such as; thus adopt inverter-driven programmes began to gradually replace throttle, bezel, valve control programmes. Frequency technology's basic principle is based on the motor speed .and power supply input frequency proportional relationship: n = 60f (1-s) / p, (-n, f, s, p represents a speed, input frequency, motor slip, motor pole logarithm); by changing the motor power supply frequency .to change the motor speed. Inverter is based on the principle of the use of AC-DC-AC power converter technology, power electronics, micro-computer control technologies in one integrated electrical products. <br> <br> III. analysis of energy .saving <br> <br> By fluid dynamics of basic laws known: fans, pumps are squared torque load and speed the flow Q, n and H and the shaft power pressure P has the following relation: Q ¡ .ø n, H, P ¡ .ø ¡ .ø n2 n3; that is, the flow is proportional to the speed, pressure and speed proportional to the square of the shaft power and speed is proportional to the cube. To a water pump, for example, its export pressure head for H0 (export .pressure head, pump inlet and outlet pipe of the static pressure difference), rated speed to n0, valve fully open resistance possession as r0, rated operating conditions and the corresponding pressure as H1, export flows to Q1. Flow-pressure curve speed-as .shown in the figure below. In-the-spot control, you typically use the pump speed run export valve control flow. When the flow is reduced from 50% in Q1 to Q2, the valve to open degree decreases so that the network becomes the .resistance characteristics by r0 r1, system operation points along the direction I from point a to point b; pressure under its throttling of H2 H1 becomes. The actual value of pump shaft power (kW) by the formula: P = Q · H / ( .η η bc ·) × 10-3. Where p, Q, c, H, η η b represent power, flow, pressure, water pump efficiency, gearing efficiency, direct drive of 1. Suppose the total efficiency (η η bc · .) is 1, the water pump from point a to point b, motor power savings and the area of AQ1OH1 BQ2OH2. If you use the pump speed means change, when the flow speed n from Q1 to Q2 is reduced by 50%, then the .network resistance characteristics for the same curve r0, system operating point II along the direction from point a to point C, pump running more reasonable. In valve fully open, only network resistance, the system meets the requirements of the site, the energy will flow .. At this point, motor power savings and the area of AQ1OH1 CQ2OH3. Compare with valve opening adjustment and pump speed control, obviously using the pump speed control more effective and reasonable to have significant energy saving effects. In addition, diagrams can also be seen .: valve regulation would make the system pressure H, this will pipe and valve sealing performance threat and destruction; and speed regulation, the system pressure H will pump rotational speed nLower and lower, it will not have adverse effects on the system. From the above .comparison is difficult for us to find out when the scene needs to pump flow rate from 100% to 50%, with speed regulation than the original valve regulated savings BCH3H2 corresponding power sizes, energy-saving rate in more than 75%. <br> .<br> Similarly, if you adopt the frequency conversion technology change pumps, fan speed control site equipment pressure, temperature, water level, and other process control parameters, you can draw a system control characteristic curve drawn above the results of the comparison. Ie ., the use of inverter technology to change the motor speed method than using valves, regulating more energy-efficient economy bezel, equipment operating conditions will be improved significantly. <br> <br> 4. energy saving calculation <br> <br> For .fans and pumps of the equipment in the frequency of energy-saving effect, generally two ways to calculate: <br> <br> 1. on the basis of known fans and pumps in the different control methods of flow-load curve and scene changes .of the load operation. <br> <br> To a IS150-125-400-type centrifugal pump, for example, rated flow 200.16m3 / h, lift-equipped Y225M-4 50m;, 45kW electric motor rated power. Pump valve .adjustment and speed regulation of flow-load curve, the following diagram. Depending on operational requirements, pump continuous 24-hour run, which run every day, 11 hours, 90% <br> <br> 13 hours of running at 50% load .; year-round operation time in 3 days. The amount of electricity each year to: <br> <br> W1 = 45 × 11 (100% -69%) × 300 = 46035kW · h <br> <br> W2 = .45 × 13 × (95% -20%) × 300 = 131625kW · h <br> <br> W = W1 + W2 = 46035 +131625 = 177660kW · h <br> <br> Per unit according to 0.5 element calculation, the annual saving electricity .8.883 million. <br>.