Part of rainwater falling on the ground can effectively replenish groundwater, raise groundwater level and alleviate the downward trend of groundwater level through infiltration technology, which has a significant effect on relieving the drainage pressure of urban rainwater and improving the flood control ability of urban drainage pipe network. Widely used in city squares, sports grounds, urban roads, lawns, courtyards, building roofs, etc. It can be used as an effective interface for collecting rainwater. Rain belongs to water resources, and the pollution is not serious. After simple treatment, it can be used in daily life, such as washing water, urban cleaning, irrigation of green space, industrial water, fire fighting water and maintenance of urban water landscape. Use urban depressions to collect rainwater and increase the area of urban rivers, lakes, water bodies and wetlands. Increase air humidity and purify the air. Suppressing the heat island effect can improve the urban environment.
One of the application fields: siphon rainwater collection system
Siphon rainwater collection system is a form of roof rainwater drainage, which uses the effective potential difference between rainwater hopper and drainage pipe as power to generate negative pressure inside the system, and its hydraulic calculation is based on Bernoulli equation of fluid mechanics. Because the system is suitable for rainwater drainage on the roofs of various buildings, it is favored by users.
It consists of rain bucket, pipe fittings and initial flow abandonment device. High density polyethylene (HDPE), stainless steel and plastic-coated steel pipes can be selected for pipes and fittings, so that the system can meet the needs of any engineering change during construction and roof rainwater can quickly enter the collection system. Automatic control of the initial discharge capacity of rainwater can accurately eliminate bad rainwater at the initial stage, and automatic control of the opening and closing of the mechanism makes the rainwater flow intelligent.
It is suitable for rainwater drainage of various building roofs (such as exhibition centers, stadiums, terminal buildings, hangars, large freight warehouses, logistics centers, factories, office buildings, etc.). ). The design of this system must adopt siphon rainwater hopper and carry out strict hydraulic calculation.
The second application field: drainage system on the same floor
The drainage branch pipe does not cross the floor, but is connected with the main drainage pipe that crosses the floor in the same floor.
Drainage technology of the same floor wall with concealed installation system as the main feature
The same layer drainage technology with drainage water collector as the main feature,
(1) Hygiene: the drainage branch pipe does not cross the floor, which avoids the leakage of sewage from the upper layer to the lower layer through the pipeline, reduces the possibility of disease spread, and also solves the problem of dew condensation on the surface of the horizontal drainage pipe in rainy days.
(2) Independence: The maintenance and overhaul of the pipeline will be carried out on this floor, which will not disturb the residents at the lower level.
(3) Safety: Preventing the concrete floor from being perforated for many times is beneficial to the integrity of the floor and reduces the possibility of spreading in case of fire.
(4) Spacious: the kitchen and bathroom should avoid the ceiling and increase the indoor headroom.
(5) Sound insulation: the drainage pipeline is installed in a concealed way, which has good sound insulation effect and reduces the interlayer transmission of water flow noise in the drainage pipeline.
(6) Freedom: there is no need to set a reserved hole in the construction of drainage branch pipe, and the sanitary ware can realize personalized decoration.
The third application field: infiltration rainwater collection system
The rainwater infiltration pipe, the rainwater infiltration well and the rainwater infiltration ditch are collected circularly as a whole;
A. Infiltration rainwater pipe: Infiltration rainwater pipe is one of the underground infiltration facilities of soil infiltration system. The rainwater collected by the infiltration rainwater well penetrates into the soil through the infiltration rainwater pipe, and the excess rainwater overflows into the landscape reservoir, which can be used in conjunction with the infiltration rainwater outlet, infiltration well, infiltration ground, etc. , can also be used alone.
B. Infiltration rainwater well: Infiltration rainwater well is a product rainwater well integrating collection and infiltration functions. It has the functions of a conventional rainwater inspection well and an infiltration rainwater outlet, which can not only eliminate surface runoff, but also carry out rainwater infiltration. Infiltration rainwater well is an underground infiltration facility of soil infiltration system. The flow direction of rainwater is as follows: the ground with seepage collects in the seepage well, some of which seeps into the ground, and some of which exceeds the seepage capacity and penetrates through the seepage pipe.
C. Infiltration rainwater ditch: Infiltration rainwater ditch is one of the underground infiltration facilities of soil infiltration system. Rainwater is collected on the ground and seeps into the soil through ditches. Excessive rainwater overflows into the landscape pool. The seepage ditch, seepage rainwater pipe, seepage rainwater outlet and seepage rainwater well form a seepage drainage system.
Infiltration green space collection and storage: Make use of the advantages of large and medium-sized green spaces such as parks, residential areas and golf courses, and rationally use existing green spaces for rainwater collection and storage. The following concave green spaces have the best infiltration effect, and pit ponds or water systems can be used to collect rainwater; In areas where groundwater characteristics are not easy to form, rainwater collection and storage systems can be built, large underground storage tanks can be built, and water-saving irrigation measures can be supported.
Collection of permeable pavements: pavements for squares, communities, parks, sidewalks, walkways and bicycle lanes: Common materials include: permeable concrete asphalt pavements, permeable floor tiles, grass paving, lawn tiles, pebbles and gravel.
The fourth application field: rainwater collection and utilization on the roof of the park.
The rainwater collection system of park buildings should be organized according to the planning layout and topography of park buildings. Culverts should be used to collect rainwater, that is, rainwater from roofs, walls and aproll should be introduced into a circular filter pool, and filter materials such as pebbles or gravel should be laid in the pool. Rainwater will seep into the filter pool and re-enter the reservoir, or be connected with the planting pool of ground plants and vertical greening plants through water collecting pipes for watering plants. The rainwater collected on the roof of park buildings is similar to that of roads, among which "high flower bed+low green space+shallow ditch infiltration" has been well received, that is, the rainwater on the roof first flows through the high flower bed for infiltration and purification, and then flows into the shallow ditch with the road rainwater through the low green space; When the rainfall is heavy, the rainwater enters the infiltration canal along the shallow ditch and continues to infiltrate; Rainwater exceeding the infiltration capacity is discharged into sewage ponds or artificial lakes.
Fifth application field: rainwater collection and utilization on the surface of agricultural greenhouse.
The plastic film surface of greenhouse is a good rainwater collection area, but most greenhouse construction does not consider the utilization of this part of rainwater. It leads to the waste of the cheapest water resources and even the local water destroys the greenhouse. If it can be done in front of the shed during construction.
The length of the shed should build an inclined water collecting basin, and a water cellar or reservoir should be built near the side wall of the shed to collect rainwater on the shed surface when it rains. Install high-efficiency water-saving irrigation and drip irrigation equipment in the shed, equip electric pumps in places where electricity is convenient outside the shed, use hand pumps to pump water in places without power supply, and irrigate greenhouse crops with pressurized irrigation facilities. This is a simple and feasible project with low cost and good effect, which is worth popularizing, especially for developing facility agriculture in arid and semi-arid areas.
The sixth application field: rainwater collection and utilization on barren slopes in mountainous areas
For hilly areas, the upper part of the mountain is forest and grassland or barren slope, and the lower part is agricultural land. Generally, the land in this area has poor water conservation effect, low infiltration rate and serious soil erosion. If we open a mountain-turning canal on agricultural land, take measures of water storage or interception to stop the flood, and then irrigate crops through flood diversion canal in drought, we can turn low-and medium-yield fields into high-yield fields. The former is to build a reservoir every 50- 100 meters along the flood diversion canal, store the excess flood in the reservoir, and take water from the reservoir for irrigation when there is drought and water shortage.