1. In order to make the technology of non-negative pressure frequency conversion water supply equipment in engineering design, construction and acceptance, to achieve advanced technology, economical rationality, safety and hygiene, convenient maintenance and quality assurance, this regulation is formulated.
2. This regulation is applicable to domestic water supply projects in which urban enterprises, institutions, and residential areas in new construction, expansion, or reconstruction use pipe network overlay (no negative pressure) water supply technology. Pipe network lamination (no negative pressure) water supply technology, such as for industrial production, fire protection and other water supply projects, should also be implemented in accordance with the current relevant norms or regulations.
3. This regulation does not apply to pipe network stacking (no negative pressure) water supply projects in related industries (hospital, pharmaceutical, chemical, nuclear industry, etc.) that may cause toxic pollution to public water supply networks.
4. The water supply design of the pipe network (no negative pressure) is consistent with the requirements of the overall urban water supply planning. According to the specific conditions of the project, the necessary rules and tests should be carried out to ensure local conditions, strive for stability, unified management and ensure safety.
5. The water pump directly from the outdoor water supply network should meet the requirements of CJ/TXXX of “Pipeline Overlay Water Supply Equipmentâ€.
6. Pipe network stacking (no negative pressure) water supply design, construction and acceptance, in addition to the implementation of this regulation, it should also comply with the relevant national standards and norms.
No negative pressure frequency conversion water supply equipment terminology: (pictured)
1. Pipe network lamination (no negative pressure) The water supply is superimposed by the water pump on the municipal water supply pipe network, and the water supply method is taken directly from the municipal water supply pipe network.
2. Pipe network lamination (no negative pressure) The water supply equipment consists of anti-fouling partition unit, variable frequency pressurizing unit, pressure compensation unit, pressure transmitter, microcomputer control unit and piping system, and is allowed in the municipal water supply network. Under the condition of the variable frequency water pump running or non-running time, the equipment can automatically and continuously supply water to the water supply network.
Pipe network laminated water supply equipment:
General provisions:
1. The water supply equipment used for pipe network superimposed water supply should have reasonable structure and small floor space: energy saving, high degree of automation, simple management and operation, safe and reliable operation, convenient installation and easy maintenance.
2. The performance, material and sanitary requirements of the water supply equipment for pipe network lamination (without negative pressure) shall meet the requirements of the local administrative department and the water supply enterprise for water supply quality, pipe network safety, water management, production scheduling and other aspects.
Pipe network lamination (no negative pressure) water supply equipment can be divided into:
l), outdoor integrated;
2), indoor integrated;
3), indoor split type.
4), pipe network laminated water supply equipment according to the presence or absence of adjustment devices can be divided into: 1)) water tank adjustment; 2)) pressure water tank adjustment; 3)) no water tank, no pressure tank adjustment.
5) When the water pump directly absorbs water from the outdoor water supply network, the water supply device shall consist of the following components: l) pump unit; 2)) suction pipe, outlet pipe and other piping systems; 3) suction pipe control valve (gate valve or Butterfly valve), outlet pipe check valve and control valve (gate valve or butterfly valve) and other valve parts; 4)) pressure sensing device; 5)) anti-backflow device; 6) diaphragm type pressure water tank (set as required); 7)) Automatic control cabinet (box).
6) The components of the pipe network superimposed water supply equipment shall comply with the relevant standards. When selecting, there shall be a product certificate or a certification mark.
7) The pipe network superimposed water supply equipment should have a reliable anti-negative pressure control system, and its working state should have obvious signs.
8) The pipe network superimposed water supply equipment should have the following protection functions: 1)) water source waterless shutdown function; 2)) double pump automatic switching, automatic inspection function; 3) no trouble long-time operation function; 4) network service function.
9) Pipe network stacking (no negative pressure) water supply system should be set up Flow Meter, pressure and other measuring instruments.
General provisions:
1. The water supply of the pipe network (no negative pressure) should be designed by the design unit.
2. The scale of the pipe network superimposed water supply project should be determined according to the water supply capacity of the local municipal water supply pipe network, combined with the scale of the community, the construction of the stage, the height of the building, the distribution of the buildings, etc., after technical and economic comparison.
3. The pipe network superimposed water supply system can adopt the following forms according to the form of municipal pipe network, annual water pressure, water stoppage and user requirements for water quality and water supply guarantee rate: 1 no high water tank, direct water supply on the lower line; High water tank, water supply to gravity.
4. When determining the form, model and specifications of the pipe network superimposed water supply equipment, many factors should be considered.
Figure 1 PLC control flow of frequency conversion control cabinet: (pictured)
Full flow high efficiency variable frequency water supply equipment:
Compared with the living water of large living quarters and high-rise buildings, if the main pump unit and the small flow pump are used separately, the difference between the small pump flow rate QL and the main pump flow rate QM is large. When the flow adjustment range is from QL to 1/3Qm, The operating efficiency of the pump is still very low, resulting in uneconomical operation of the pump and wasting energy. And frequent pump changes occur when the flow is greater or closer to QL. In order to achieve high efficiency operation of the pump in the full flow range, it is necessary to add a medium flow pump, the flow rate can be 1/3 Qm ~ 1/2 QM. Two medium flow pumps can be added in special cases. In this way, the overall pump flow rate selection is stepped, so that the equipment is in the high efficiency section of the pump when running in any flow section, which is more energy efficient.
The control cabinet of the frequency conversion cabinet is composed of PLC and multi-function PCS-PID regulator. Take the three pump configurations as an example. The control flow of the system is shown in Figure 2. The system can also realize double constant pressure water supply function, low constant pressure water supply when the medium pump and small pump are frequency conversion, and high constant pressure water supply when the main pump is frequency conversion.
Figure 2 Three pump frequency conversion control process: (pictured)
Three pump frequency conversion control flow chart 1:
Three pump frequency conversion control flow chart 2:
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