Weifang Odea Machinery Co., Ltd.
Address: Weifang Economic zone,Weifang city,Shandong Province ,china
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How Cement products business measures to reduce energy loss
Q: What is the power factor? Why improve the power factor can reduce the power loss?
A: The power factor refers to the phase difference between the current and the voltage cosine of the angle. Its value depends on the nature of the load. When the access circuit purely resistive load, the power factor up, cos = 1; if the access inductive load circuit power factor less than one. Widely used in industrial AC induction motor, the case of inductive loads. Its full load power factor of between about 0.7 to 0.9, at no load or light load, the power factor is lower.
As we all know, generators and power transformers rated capacity apparent power is expressed. The unit is kVA. It is the product of voltage and current rms. When the voltage is constant, which depends on the capacity of the current value. The current value of the active component and reactive component composition. Active component by electrical equipment or appliances convert electrical energy into mechanical energy or thermal energy to be fully utilized. Generator, this one is called active power. No reactive component has not been utilized. But reactive current in power lines, generators and power transformers to produce the same resistive losses and waste of energy. This loss, commonly referred to as reactive power loss. Reactive current generator, the output is the reactive power. If the reactive component of the load increases, which reduces the power factor, reactive power, the generator is also increased, to cause the generator can not be fully utilized. For example, the capacity of the generator is S = UI, when the voltage and current of the generator reaches the rated power factor if the circuit is 0.5, then the generator active power P = 0.5UI = 0.5S. In this case, only half of the rated power generator output capacity. For power transformers as well. Therefore, the electricity sector was particularly pay attention to the user's power factor, reactive power is to reduce losses and improve the utilization of the generator and the power transformer.
Q: How to improve the production equipment and cement products manufacturing plant power factor?
A: Because cement products manufacturing equipment, AC induction motor and welding machines use a lot. Such electrical equipment compared with other electrical equipment, the power factor is low. Coupled with the production plant on the selection and use of the motor properly. Therefore, the current domestic cement products manufacturing plant power factor is low.
Cement products manufacturing plant power factor improvement, it should first consider how the rational use of electric motors and other electrical equipment. Then use the plant substation power factor compensation to improve the power factor. Cement manufacturing equipment, the capacity of the larger or greater impact on the whole plant equipment power factor are: reinforced straighten cutter, tension machine, wire drawing machine, spot welding machine, welding machine, welding machine, self-stressing cement mill , centrifuges, hanging roller machine, shaking table, vertical pipe extrusion machines and other equipment. Most of these devices are based on a low power factor of AC induction motor or a step-down transformer. To improve the power factor above the device measures are the following:
1, in the selection of the motor, the size and characteristics of the mechanical load should be a reasonable choice of motor type and capacity. At present, the domestic manufacturers in the selection of the motor, often only consider the reliability of the equipment, while ignoring save energy and improve power factor. Therefore, the capacity of the motor is selected to be larger, and some even more than the required capacity of equipment more than doubled. Thus, the motor in the long run when the light load efficiency and power factor is very low. For example, they use a long centrifuge light load operation of the AC motor. If you switch to short overload larger DC motor, the motor capacity can reduce by more than half, which is to improve the power factor is clearly beneficial.
2, change the start-up mode, the motor can run at full capacity. Since AC induction motor starting current and starting torque small, often can not meet the full load starting requirements. This could be changed to no-load starting, start and then put into full load operation. For example, wire drawing machines, tensioning machines and vertical pipe extrusion machine can start using this approach. This can reduce the capacity of the motor, but also improve power factor.
3, for the use of step-down transformer welding machine, welding and spot welding, avoid no-load operation, such as welding installation of automatic load disconnecting device can avoid no-load operation.
4, the number of starts small, and the long-running device, such as a ball mill, the choice of high power factor of the synchronous motor. Because not only can control synchronous motor power factor is equal to 1 in the case of running, but also run in advanced phase angle. So, after using the synchronous motor, it can lag phase angle compensation AC induction motors and transformers and other inductive loads, so that the plant power factor improvement.
Plant substation can be used in two ways to improve the power factor: