Renovation of single buildings in old communities, ends of village and town pipe networks, and low-rise residential buildings often encounters such working conditions: there is water at the entrance and a certain pressure, but the pressure on the top floor or at the most unfavorable point is not enough during peak water use. Compact Direct-Connect Water Booster Station integrates the pump unit, frequency conversion control, instruments and pipelines into a cabinet, which can complete local pressurization under appropriate access conditions. To determine whether this type of equipment is suitable, you need to look at the water source conditions, control methods and user-side needs at the same time.

A. First distinguish the two ways of water inlet

When the equipment is connected to a water supply pipe network with available pressure, the water pump supplements the required water head based on the inlet pressure to form a superimposed pressurized water supply; when the equipment draws water from a water tank that meets the requirements, it is a pressurized water supply after the water tank has been adjusted. The two methods can use similar cabinet structures, but the design conditions for water source protection, pressure calculation and control protection are different.

If you install a pump directly on the water supply facility to pump water, you must obtain the consent of the water supply unit in advance. Article Thirty-Three of the current "Water Supply Regulations" clearly stipulates this. The project should first verify the access conditions, allowable water intake, and minimum available pressure before determining the system plan. Direct connection cannot be judged simply by "the pipeline can be connected".[Regulatory basis]

If the water inflow is insufficient for a long time, the water supply time is limited, or the available pressure at peak cannot meet the design boundary, the storage and water supply plan should be re-evaluated. The booster pump can only replenish energy to the water flow, but cannot make up for the flow gap of the water source itself.

B. How to control the pump unit using pressure feedback

A typical system consists of water inlet and outlet main pipes, filtration and valve components, water pumps, pressure tanks, pressure sensors and control systems. After the outlet pressure is fed back to the controller, the controller compares the actual measured value with the target value, and then adjusts the pump speed and start and stop. EPANEL YP-S1 product information adopts one-to-one configuration of frequency converter and water pump, which facilitates the adjustment of operating status of each pump according to needs.

When the water consumption increases, the controller increases the output according to the pressure deviation, and the pump group with corresponding configuration can also put in other working pumps according to the confirmed strategy; when the water consumption decreases, the speed is reduced or the number of operating pumps is reduced. Whether to sleep at low flow, how to wake up, and when to rotate the working pump should be based on the actual control program and debugging results.

Pressure closed loop does not mean that arbitrarily increasing the set value will result in better water supply. Setting the value too high may increase low-level user pressure, valve load and operating energy consumption. A reasonable goal is to control the maximum pressure elsewhere in the system while meeting water requirements at the most unfavorable point.

C. The entrance, exit and anti-backflow boundaries must be checked separately.

Entrance side:Record the dynamic pressure and available flow corresponding to the peak water consumption, and set low-pressure, water shortage and other protections according to the water supply unit and design requirements. The pressure point should reflect the actual suction working conditions as much as possible; if the measuring point is far upstream, the height difference of the measuring point, the loss of the filter and the water inlet pipeline must also be considered.

Exit side:In addition to the water supply pressure at the design flow rate, the system pressure at small flow rates, at night, and when the inlet pressure rises must also be checked, and the allowable working pressure of the water pump and the pressure bearing capacity of pipelines and valves must be checked. The pressure location, measuring range and installation status of the outlet sensor will also affect the control results.

Connection side:Set corresponding backflow prevention measures according to access conditions and pollution risks. The functions and applicable conditions of ordinary check valves and special backflow prevention devices cannot be simply equated; hygiene and safety, cleaning and disinfection, and operation and maintenance are also part of the system design.

D. How to understand several parameters of small integrated equipment

The current product information of EPANEL YP-S1 covers the flow range of 1-44 m³/h, and provides two-pump and three-pump configurations. The dimensions of the two-pump cabinet in the data are 900×450×1200 mm, and the dimension of the three-pump cabinet is 1200×600×1300 mm, both expressed in width×depth×height. The two-pump cabinet body occupies approximately 0.405 m², but maintenance, door openings, pipe connections and basic dimensions still need to be reserved separately.

"Two pumps, three pumps" indicates the total number of installations, which does not automatically mean that all water pumps are used as working pumps at the same time. The working, standby, rotation and parallel strategies should be clearly defined during model selection. The equipment flow rate given in the sample cannot be directly multiplied by the number of pumps.

The main function of the air pressure tank is to participate in small flow regulation and pressure buffering. Its effective adjustment of water volume is affected by the precharge pressure and operating pressure range. 8 L in the sample is the nominal volume and cannot be understood as the available emergency water storage of 8 L. According to the product information, 304 stainless steel is also limited to the corresponding current-passing parts and cannot be extended to the entire cabinet being made of the same material.

E. Submit on-site data to model selection instead of just reporting the number of households

Before carrying out the scheme design, it is advisable to sort out the service scope and water type, the height difference of the most unfavorable point, peak and small flow requirements, water inlet pressure changes, inlet and outlet pipe diameters, power supply conditions and installation space. The reference number of households in the sample is suitable for assisting preliminary screening and cannot replace design flow calculation and on-site investigation.

For existing variable frequency boosting systems, "insufficient water source", "large pipeline loss", "unreasonable pressure setting" and "insufficient pump set matching" should also be distinguished first, and then decide whether to replace the equipment. Only in this way can the installation convenience of cabinet integration be transformed into verifiable water supply improvements.

Continue reading:Compact Direct-Connect Water Booster Station selection calculation: flow rate, boosting head and commissioning and acceptance. Product configuration can be viewedEPANELCompact Direct-Connect Water Booster Station。

Data basis and further reading

Equipment parameters are based on the EPANEL YP-S1 product brochure and specifications and model information; the specific configuration is subject to the technical documents confirmed by the project.

The official full text of the "Water Supply Ordinance" · GB/T 38594-2020 "Pipe Network Overlay Water Supply Equipment" Standard Information · The function of the pressure tank and adjusting the water volume