Multi-pump parallel connection multi-frequency-conversion synchronous speed regulating water supply control system and control method thereof

Abstract

The invention discloses a multi-pump parallel connection multi-frequency-conversion synchronous speed regulating water supply control system and a control method thereof, and relates to the technicalfield of water supply equipment. The problem that water supply is low in efficiency and instable is solved. The system comprises a preset number of water pumps, frequency converters, a sensor, a PLC,a human-computer interface and an industrial 5G router. The water pumps of a preset number are connected together in a multi-pump parallel connection manner, and each single water pump is connected with the corresponding frequency converter; the PLC is connected with the frequency converters and controls running of the water pumps; the sensor is connected with the PLC; the human-computer interfaceis connected with the PLC and achieves human-computer interaction; and the industrial 5G router is connected with the human-computer interface, and equipment managers can remotely control the systemthrough the industrial 5G router. The control system is simple in structure, low in fault rate and precise in control, stepless speed regulating, synchronous frequency regulating, high efficiency andenergy saving are achieved, the multiple pumps are connected in parallel, and flow is subdivided.

Description

technical field [0001] The invention relates to the technical field of water supply equipment, in particular to a water supply control system. Background technique [0002] At this stage, there are many types of water supply equipment. The common ones on the market are tank-type water supply equipment and tank-type stacked water supply equipment. The equipment is generally composed of water tanks, pump sets, pipes and valves. The pump group generally has 2-3 water pumps, which are driven and operated by a frequency converter. When the equipment is running, the speed of the water pump is adjusted by the frequency converter to meet the water pressure constant of the user. If the flow of one water pump is insufficient, it can be started in sequence. Other power frequency water pumps to make up the flow. [0003] The above-mentioned water supply equipment has the advantages of low cost, simple control system design, and low entry barriers, so it is favored by many small compani...

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Problems solved by technology

[0004] 1. Conventional equipment only has one frequency converter, and it is impossible to adjust the frequency of each pump. Instead, use a contactor to make the remaining pumps run at power frequency

[0005] 2. The water demand at the user end changes rapidly and the time-varying coefficient is high, which requires the system to have sufficient response speed, while the conventional equipment system responds slowly, the adjustment is unstable, and the pressure fluctuates greatly. The maximum and minimum values ​​can differ by 0.1MPa or even more Big

[0006] 3. When conventional equipment controls the increase or decrease of water pumps, only one water pump is always in the state of frequency conversion adjustment, and the rest of the water pumps are operated at power frequency. Therefore, when the power frequency water pump is put in and removed, it will bring greater water pressure. Fluctuations, and at the same time have a greater impact on the power grid

[0007] 4. When conventional equipment operates with multiple pumps at the same time, due to the different actual working points of the power frequency pump and the variable frequency pump, the water flow and lift of each pump cannot be distributed in a balanced manner, which will cause mutual inhibition within the system, especially the variable frequency pump. It is more likely to be suppressed by power frequency pumps. The most intuitive manifestation is that the flow rate of the pumps will appear 1+1<2. The more the number of parallel pumps, the more obvious this phenomenon. This is also the reason why the number of parallel pumps in many water supply equipment will not The root cause of more than 3

[0008] 5. Due to the unavoidable mutual inhibition within the system, the system will lose a large part of the head and flow, which will increase the energy consumption of the system and reduce the efficiency, which is not conducive to the national strategic goal of energy conservation and emission reduction, and also makes users bear the burden Increased operating costs such as electricity and maintenance

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