6 Major Considerations for Purchasing Secondary Water Supply Equipment

6 Major Considerations for Purchasing Secondary Water Supply Equipment

Source: China Government Procurement Network

Secondary water supply equipment is an indispensable equipment in the clean water supply system of high-rise buildings. The basic working principle is to use tap water pipe network overlay technology to deliver clean water to floors at a specified height to meet people's daily needs.

The main technical characteristics of secondary water supply equipment: 1) Using the pressure of the tap water pipe network to superimpose and pressurize, while using the frequency conversion control system, high-efficiency energy-saving motors and water pumps, high-efficiency and low-consumption operation, to ensure continuous and stable water supply; 2) Fully enclosed pipelines Operation, compact structure, small footprint; abandon the original reservoir, foreign objects can not enter the pipeline system, to prevent secondary pollution; 3) good system protection, monitoring, monitoring functions, the system runs through wired and wireless transmission methods remote control.

The secondary water supply equipment is mainly composed of three-phase asynchronous motors, water pumps, pipelines, valves, steady flow compensators, vacuum suppressors and electrical control cabinets. It converts electrical energy into potential energy of water through the work of a motor, that is, the head of clear water. For the secondary water supply equipment that runs every day and consumes a lot of electric energy, improving the efficiency of electricity use, reducing energy consumption, and saving electricity are the indicators that users are most concerned about. So how to choose high-efficiency and energy-saving secondary water supply equipment?

Energy-saving evaluation standards for secondary water supply equipment

There are more than a dozen national recommendations for secondary water supply equipment and standards issued by the Ministry of Construction. However, none of them has stipulated energy-saving indicators for secondary water supply equipment. In June 2015, the China Quality Certification Center completed and issued CQC3153-2015 "Technical Specification for Energy-saving Certification of Secondary Water Supply Equipment", which stipulated the requirements and test methods for energy-saving evaluation of secondary water supply equipment. This technical specification has become the energy-saving specification for secondary water supply equipment. The necessary criteria for evaluation.

Naming method of secondary water supply equipment

There is no uniform standard for the naming of secondary water supply equipment, and the enterprise shall name the secondary water supply equipment according to its own naming rules. Generally, the model specifications include the lift, flow, single motor power and number of motors of the secondary water supply equipment.

According to Article 22 of the "Urban Water Supply Regulations" [State Council Order No. 158]: Urban tap water and water supply enterprises and enterprises that build their own facilities for external water supply shall maintain uninterrupted water supply. Therefore, it is required that the secondary water supply equipment, as an important equipment of the water supply system, cannot stop working for a long time. When the equipment fails, the standby pump in the equipment should be started, and the damaged unit should be replaced at any time to maintain uninterrupted water supply. In the model designation, if it is calibrated to 2 pumps, this structure is called the "one use, one standby" structure in the industry, that is, one working pump and one standby pump. It is calibrated to 3 pumps, which are called "two use and one standby", two working pumps, one standby pump, and so on.

For example: secondary water supply equipment model ESW, specifications: flow 6m3/h, head 32m, 2 sets of 1.1kW motors, 2 sets of equipment, the equipment structure is one use and one backup. Use the following method to name the model specification:

Appearance diagram and basic composition of secondary water supply equipment

Key indicators for purchasing secondary water supply equipment

1. Energy consumption per unit of water supply

The electric energy consumed by the secondary water supply equipment to raise 1 ton of clean water by 100 meters is in kilowatt·hour per cubic meter·megapa (kWh/m3·MPa). See the table below for specific requirements:

2. Flow and head

The user selects the secondary water supply equipment with suitable flow and head according to the size of the clean water demand and the delivery height. The flow rate is different, the unit water supply energy consumption value of the secondary water supply equipment is different.

Main product categories and features

There are two types of secondary water supply equipment: tank-type pipe network overlapped (no negative pressure) frequency conversion secondary water supply equipment and box-type pipe network overlapped (no negative pressure) frequency conversion secondary water supply equipment (Note: product name depends on Enterprise naming methods are different), the latter equipment is to add a low-level water tank and related water pumps on the basis of the former equipment. The main functions of the low-level water tank are: 1) users with higher water supply guarantee rate; 2) when there is a short-term When the water pressure in the water pipe network is insufficient or the water peak causes the water pressure to be too low and the water volume is insufficient, the effect of supplementing the water volume and increasing the water pressure.

Product considerations

1. The flow and pressure of the equipment should match the building water supply system

The design, selection and installation of secondary water supply equipment should be implemented in accordance with national standards and industry standards. The design flow of the equipment should comply with the requirements of GB50015-2003 (2009 Edition) "Code for Design of Building Water Supply and Drainage". The selection and installation of equipment should comply with 12S109. Selection and Installation of Overlapping (No Negative Pressure) Water Supply Equipment". It is unreasonable to select the flow and pressure of the equipment to be too small or too large. If the flow and pressure of the equipment are too small, it will cause insufficient water supply and affect the user's water use effect; the selection of the flow and pressure of the equipment will cause equipment idleness and cost waste. Therefore, the purchaser should choose secondary water supply equipment that matches the flow and pressure required by the building's water supply system.

2. Required qualifications

Secondary water supply equipment is the equipment that delivers clean water for domestic or industrial use to users. Water safety is very important. Therefore, secondary water supply equipment must have the following qualifications: the water product sanitation license issued by the Ministry of Health and the equipment standards of various water companies Entry permit.

3. Pay attention to energy-saving indicators and certification marks

CQC3153-2015 "Technical Specifications for Energy Conservation Certification of Secondary Water Supply Equipment" stipulates the unit water supply energy consumption value of secondary water supply equipment. The more pumps used, the higher the efficiency and the lower the unit water consumption energy consumption. In order to ensure the high efficiency of the secondary water supply equipment and the low energy consumption per unit of water supply, it is also required that the three-phase asynchronous motor and the clean water centrifugal pump used in the secondary water supply equipment must use high-efficiency and energy-saving products. Phase Asynchronous Motor Energy Efficiency Limitation Value and Energy Efficiency Grade "Energy Efficiency Level 2", the clean water centrifugal pump meets the requirements of the energy saving evaluation value in GB 19762-2007 "Clear Water Centrifugal Pump Energy Efficiency Limitation Value and Energy Saving Evaluation Value".

The energy-saving characteristics of secondary water supply equipment are identified and evaluated by the China Quality Certification Center through certification methods. The qualified equipment is evaluated as energy-saving equipment, and the equipment manufacturer clearly indicates it by pasting the "section" certification mark.

4. Choose an optimized product

In addition to technical indicators, you should also consider more optimizing products: 1) Whether to install a remote monitoring system, the remote monitoring system can monitor, transmit and control (some systems achieve control functions) the operating status of the secondary water supply equipment, and retrieve real-time water affairs data. Finding the fault status of the equipment in time and perfecting daily maintenance can realize the unattended pump room. 2) Whether the noise of the pump room meets the standard, the noise of the pump room can be transmitted from the pump room to the household floor through pipes and buildings. If the noise of the pump room exceeds the standard, especially the low-frequency noise of the pump, it will bring very uncomfortable feelings to the residents.

5. Pay attention to the after-sales service level of the product manufacturer

In order to ensure the safety, reliability, sanitation and public interests of the building's water supply, and to improve the management level of after-sales operation and maintenance of the secondary water supply equipment manufacturer, attention should be paid to the secondary water supply equipment manufacturer’s consideration of the pump room environment, water supply equipment, disinfection system, sewage system, The establishment and operation management of maintenance management systems such as pipelines and valves. China Quality Certification Center will request and evaluate the service level and quality of manufacturers of secondary water supply equipment.

6. Precautions for equipment selection

According to the "Selection and Installation of Overlapping (No Negative Pressure) Water Supply Equipment" issued by the China Building Standard Design and Research Institute, the overlapping water supply method shall not be used in the following situations: 1) Water supply at a fixed time; the total amount of water supply cannot meet the water demand; water supply pipes The available water head of the network is too low, the pressure fluctuates, the pipe diameter is too small, and the water supply department considers the areas that are not applicable; 2) Factories, scientific research institutes, warehouses, etc. that research, manufacture, process, and store hazardous chemicals such as toxic substances and drugs Sites, user areas where no water supply is allowed.