Application of the hottest alpha frequency convert

  • Detail

Abstract: This paper introduces the application of alpha 2000 square torque converter in the energy-saving transformation of water pump central air conditioning

key words: fans, pump frequency converters, energy saving

system overview

central air conditioning is a major power consumer in the building, and the power consumption of air conditioning accounts for about 60% of the annual electricity bill, so the energy-saving transformation of Central air conditioning is particularly important. During the design, the central air conditioning system must be designed according to the hottest weather and the maximum load, with% design allowance. But in fact, most of the time, the air conditioner will not operate at full load, and there is a large surplus. The refrigerating machine of the central air-conditioning system can be loaded or unloaded according to the load change, but the chilled water pump and cooling water pump cannot be adjusted accordingly with the load change, which is a great waste. Therefore, the potential of energy saving is great

energy saving scheme

the central air conditioning system is usually divided into two systems: chilled (medium) water and cooling water (as shown in the figure below, the left half is the chilled (medium) water system and the right half is the cooling water system). According to the latest information at home and abroad, and through the investigation of many successful examples of closed-loop control transformation in the central air-conditioning water pump system, most of the energy-saving transformation schemes of the water pump system now use frequency converters

the flow and differential pressure of the water pump system are adjusted by valves and bypass. Therefore, there are inevitably large closure losses and large flow, high pressure and low temperature differences, which not only waste a lot of electric energy, but also cause the end of the central air conditioning to fail to achieve a reasonable effect. In order to solve these problems, it is necessary to make the water pump adjust the water flow with the change of load and close the bypass

again, because the water pump adopts the Y - △ starting mode, the starting current of the motor is 3 ~ 4 times of its rated heart flow, and the starting current of a 90kw motor will reach 500A. Under such a large current impact, the service life of the contactor and motor will be greatly reduced. At the same time, the mechanical impact during starting and the water sag during stopping the pump are easy to cause damage to mechanical parts, bearings, valves, pipelines, etc., increasing the maintenance workload and spare parts Cost of spare parts

to sum up, in order to save energy and costs, it is necessary to transform the water pump system and adopt special frequency converters for fans and pumps, so as to save energy and prolong the service life of motors, contactors, mechanical parts, bearings, valves and pipelines. This is because the frequency converter can adjust the speed of the water pump electric experiment machine body according to the load change of the chilled water pump and cooling water pump. The cylinder body and the upper beam are connected by four columns at the starting speed of the machine. Under the condition of meeting the normal operation of the central air conditioning system, the chilled water pump and cooling water pump can be adjusted accordingly, so as to achieve the purpose of energy saving. When the speed of the pump motor decreases, the electric energy absorbed by the motor from electricity will be greatly reduced

reduced power consumption △ p=po (1 - (N1/N0) ^3) (1) formula

reduced flow △ q = Q0 (1 - (N1/N0)) (2) formula

where N1 is the changed speed, N0 is the original speed of the motor, P0 is the motor power consumption at the original motor speed, and Q0 is the pump flow generated at the original motor speed. From the above formula, it can be seen that the reduction of flow is directly proportional to the power of speed reduction, but the reduction of power consumption is directly proportional to the power of speed reduction. For example, assuming that the original flow rate is 100 units and the energy consumption is also 100 units, if the speed is reduced by 10 units, from (2) formula △ q = Q0 [1 - (n1/n, such as 1 ton or more 0)] = 100* [1 - (90/100)] materials cross stack at right angles = 10, it can be concluded that the flow rate has changed by 10 units, but the power consumption is changed from (1) formula △ P = P0 [1 - (N1/N0) ^3 = 100 × (1 - (90/100) ^3) = 27.1 It can be concluded that the power will be reduced by 27.1 units, that is, 21 inputs will be reduced by 7.1% compared with the original. Again, because the frequency converter is a soft start mode, after using the frequency converter to control the motor, there is no impact current during the starting and operation of the motor, and the impact current is the most important and direct factor affecting the service life of the contactor and motor. At the same time, using the frequency converter to control the motor can also avoid the phenomenon of water sag, so the service life of the motor, contactor and mechanical parts, bearings, valves and pipes can be greatly extended

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