Second water supply and urban water supply is the main component of water, is to meet the quality requirements, improve water and protecting the people's health. With the rapid development of national construction in China, with the increasing popularity of water supply, secondary also produced many problems, especially secondary supply of water pollution and energy waste problem more prominent, users react strongly, for solution.
1 our second water supply, water pollution problems
The second water tap water pollution refers to water facilities in secondary storage and pressure from contaminated, when users tap water tap water reach the living standard and hygiene standards. The water pollution causes during water supply is mainly secondary pools of facilities for design, construction, water tank caused by improper management and maintenance. According to not complete count, in the secondary pollution, water tank caused by pool water pollution, reached more than 70%.
Due to the pool, and overflow tank sealing lax ventilation tube protective cover conduit, damage, make water tank is often sink, sundry, dirt or animal bodies such pollution, Tank, improper selection of materials, the pool design unreasonable, cleaning and disinfection inferior or not standard, the water pollution. According to the report, a city of health and anti-epidemic departments each year for all regions of the water tank set pool, inspect, although have, but not a sterilization equipment with the water for drinking water all.
According to the pool, cistern, water-quality problems have taken many measures, such as to pool, reasonable design, selection of tank, strengthen management, strict imported frequency conversion technology, etc, but the result unsatisfactory, only for expediency. On May 24, 2005, the construction of urban water supply "secondary pollution, management is more profound understanding" report, improve water quality, ensure "safe" water is related to people's life safety and body health, and will directly affect the innumberable families.
2, the second supply energy waste problem
According to the data analysis, the majority of the second in the pumping stations for water supply energy cost twice over 30% ~ 40%. In building a resource-conserving, environment-friendly society, under the new situation of the important measures of energy saving is imperative, but the second water conservation function and the common problems in society is not getting enough attention, some of energy-saving building regulations and often involves heating, air conditioning, the energy consumption and constructions in the water supply professional especially energy is rare, many designers also not adjust water conservation important position during the running water, caused a lot of energy, and the main existing problems are:
1 do not fully using the tap water supply pipe pressure directly, or the original pipe pressure release to pool, cistern again by zero pressure to pressure, serious waste of energy,
2 the water pipes to accurately grasps the actual supply pressure (usually refers to the lowest water pressure), cause the water-supply system zoning and energy-saving design is not reasonable,
Improper selection of equipment, (3) the "big malah car" low consumption situation seriously,
4 the pump is reasonable, the energy saving measures, there still pumping power saving potential.
3, saving energy and water supply to prevent secondary pollution
Second, the water in the pool of water to prevent water pollution, the most direct and efficient solutions is cancelled pool, cistern, eliminate water pollution, this is also the source of the chase solution.
For saving water, also should make full use of water supply pipe pressure, the building drainage design specification (GB 50015-2003) first 3.3.1 regulation: should try to use the city water supply pipe pressure directly, The residential building standard (GB 50368-2005) and the 8.2.2: drinking water system should make full use of urban water supply pipe pressure directly. According to the relevant provisions of the state, city water supply network service pressure shall not be lower than the service, the aerage 0.28 MPa pressure rating can meet the following six general buildings, and six floors above water supply all belong to the category of secondary supply. Our common secondary water has the following four:
Water supply: (1) high water pipe, water pump, pools or high water tank, and users. The field of water supply in China during the application, the stable supply pressure, high reliability, But the highest by high pressure water tank installation position limit, covering much noise, water quality, long construction period, the serious pollution, water tank is released into the pool or cannot use water pipe pressure.
(2) : tap water pipe pressure tank, and pools or pump pressure tank, and users. Air pressure tank instead of using water tank, installation is high, the area is relatively small, flexible But the pressure fluctuation is big, the pump efficiency is low, the average pump head pressure difference exists for the extra cost of energy, and must be futile, to increase the energy consumption, and 15% ~ 25% cannot use water pipe pressure, water pump, saving energy consumption, pump start-up frequently.
(VFD water-supply modes: tap water and water pipes, water pump, water pool or users. Pumps, water supply for the variable-frequency operation, high pressure constant pressure tank, saves the water, reduce pollution and such area, Disadvantages: not using water pipeline pump water pump, and the pressure of the original pools of water, it still exists or cover an area of big, high investment, management and maintenance of trouble nor fundamentally solved the problem of water pollution.
Therefore, the above three kinds of water tank, there were pools, for the traditional mode, the second cannot fundamentally solve quadratic supply of water pollution and energy waste problem.
4 no negative tap water way: "no negative pressure water pipes, users. Equipment, No way is negative in water supply mode frequency developed on the basis of a new kind of water, and secondary water pipe directly take not produce negative pressure, cancelled pool, water tanks, which solves the problem of water pollution during water and tap water pipe pressure can reach