How to transform the hottest pump to save energy b

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How to transform the water pump to save energy by frequency conversion

most of the loads of the production equipment of industrial enterprises are AC asynchronous motors, and the power consumption accounts for about 65% of the total power consumption of the enterprise. In particular, the efficiency of water pump loads is relatively low. After China's accession to the WTO in 2002, enterprises must improve economic benefits by reducing costs. In order to enhance competitiveness, saving electricity is an important economic link in reducing production costs. For example, in a water supply station, the water supply system is adjusted according to the demand of water consumption, and the flow is adjusted by adjusting the pump outlet valve. Special personnel are required to be on duty, and the valve is opened and closed under different circumstances. At the same time, due to the forced throttling of the valve, the pump forms a vortex impact, which produces strong vibration and noise, which increases the adverse losses on the service life, maintenance and repair of the pump. Then, because the torque of the motor is basically constant, the water supply pressure formed by this regulation method is high, resulting in serious throttling power loss, pump efficiency reduction, and power waste

II. Speed regulation performance of frequency conversion and energy saving transformation of water pump

when the water pump changes the speed, its internal geometric size does not change. Therefore, according to the similarity principle of the water pump, when the speed changes, the flow is proportional to the speed, the head is proportional to the square of the speed. ISO 650 graphene photosensitive elements: a group of scientists from Singapore who specialize in graphene material research 2 is proportional, and the shaft power is proportional to the cube of the speed, It is concluded that when the speed of the same pump changes, the main performance parameters of the pump will change according to the above proportional law, and the efficiency can be kept basically unchanged in the change process. If the speed of the pump unit is adjustable, we can change the speed of a pump to adapt to the change of water demand at that time, so as to avoid the motor overload caused by the operation of the pump unit in the low efficiency area. On the other hand, physical experiments, teaching research Quality control and other indispensable testing equipment can also avoid waste caused by high water supply pressure. At the same time, the shaft power is greatly reduced as the speed of the water pump slows down, and the input power of the motor is also reduced. This is the energy-saving effect of the speed regulating water pump in the water supply system

III. pump principle of speed reduction in water pump frequency conversion and energy saving transformation

according to the speed relationship in the working principle of AC motor, n=60f (1-s)/p, it is concluded from the formula that changing the power frequency of the motor stator winding evenly can smoothly change the synchronous speed of the motor. When the speed of the motor slows down, the shaft power will be reduced accordingly, and the input power of the motor will also be reduced. This is the energy-saving effect of water pump speed regulation

the physical property of AC motor speed is a slightly downward inclined curve, as shown in Figure a. the characteristics during speed regulation are still slightly downward inclined curves, which are a group of curves equal to each other at different frequencies, as shown in Figure B:

from figures a and B, it can be seen that the speed regulation characteristics of frequency converter basically maintain the inherent speed characteristics of motor, which is a group of characteristic curves parallel to each other at different frequencies

variable frequency speed regulation has the following advantages:

① small slip rate and slip loss, and the efficiency can be as high as 90-95%

② realize smooth stepless speed regulation, with high precision, wide speed regulation range (0-100%), and large frequency variation range (0-50Hz)

③ large starting torque (up to 1.1 times the rated value), realizing soft start and reducing the impact of starting current

④ improve the power factor at the electric side

⑤ the frequency converter can adopt a high-speed 16 bit CPU to cooperate with a special large-scale integrated circuit, and use software to realize v/5 automatic adjustment. It has the function of online control with computer programmable controller, which is easy to realize the automatic control of the production process

⑥ easy installation, convenient debugging and simple operation

⑦ it is not only applicable to the energy-saving speed regulation of water pumps and fans, but also applicable to the transformation of old equipment. It has an obvious effect on improving the process conditions and the quality of e-residual indentation depth increment products in the production model

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