A method for checking and detecting a separate flow drainage pipe network system

Abstract

The application discloses a kind of shunt system drainage pipe network system checking and detection method, including step 1, to the drainage pipe network is carried out system survey, the information of drainage pipeline is recorded, and regional rainwater and sewage drainage pipe network system diagram is prepared;Step 2, based on the regional rainwater and sewage pipe network system diagram prepared in the step 1, sewage pipe network is generalized and handled, and sewage drainage pipeline topological relationship diagram is formed;Step 3, based on the sewage drainage pipeline topological relationship diagram formed in the step 2, monitoring point node is drafted, for drainage information collection in drainage pipe network.The present application process is clear, easy to implement, can fully combine the advantages of water quality and quantity monitoring and pipe network detection, form pipe network system initial diagnosis by water quality and quantity monitoring, facilitate to master drainage pipe network system problem, after pipe network detection detailedly check pipe network specific problem and point, realize pipe network problem rapid diagnosis, greatly improve the checking efficiency, reduce cost input, reduce checking period, guarantee checking effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drainage pipe network, in particular to a method for checking and detecting a separate-flow drainage pipe network system. BACKGROUND

[0002] With the continuous acceleration of urbanization, the urban drainage system plays an increasingly important role in urban development and people's daily life. However, due to the increase of the service life of drainage pipes, some pipe network diseases and pipe defects problems of the urban drainage pipe network system gradually appear, such as rainwater and sewage pipe mixed connection, river water backflow, pipe sedimentation and damage, etc., which seriously affect the water conveying capacity of the drainage pipe network system and the collection efficiency of pollutants. Therefore, it is necessary to check the drainage pipe network, find out the problems and improve the pipe network system.

[0003] The commonly used pipe network problem diagnosis methods at present include operation data monitoring and drainage pipe network detection. The former mainly includes analysis and determination of water quantity and water quality operation data, and the latter includes closed-circuit television detection (CCTV), periscope detection (QV), laser detection and sonar detection, etc. However, the urban drainage pipe network is large and complex, the operation data monitoring technology has high requirements, is greatly affected by the environment and cannot accurately locate the problem points; and the drainage pipe network detection is not only high in cost, but also time-consuming and laborious, and at the same time, the drainage pipe network detection focuses on pipe section problems and lacks understanding of the overall operation condition of the drainage system. Under the requirement of improving quality and efficiency, there is no reasonable and efficient pipe network problem checking and diagnosis method at present. SUMMARY

[0004] The purpose of the present application is to solve the above problems and provide a checking and detection method for a separate-flow drainage pipe network system which is low in detection cost and efficient.

[0005] In order to solve the above technical problems, the present application adopts the following technical scheme: a checking and detection method for a separate-flow drainage pipe network system, comprising the following steps:

[0006] Step 1: conducting a system survey on the drainage pipe network, recording the information of the drainage pipe and preparing a regional rainwater and sewage drainage pipe network system diagram;

[0007] Step 2: based on the regional rainwater and sewage pipe network system diagram prepared in step 1, conducting a generalization treatment on the sewage pipe network to form a sewage drainage pipe topology relationship diagram;

[0008] Step 3: based on the sewage drainage pipe topology relationship diagram formed in step 2, preparing a monitoring point node for collecting drainage information in the drainage pipe network;

[0009] Step 4: based on the monitoring point node prepared in step 3, dividing the sewage drainage pipe into zones and numbering them respectively;

[0010] Step 5, based on the drainage information collected in step 3, draw a sewage drainage pipe network water quality and quantity topology graph;

[0011] Step 6, based on the drainage information collected in step 3, evaluate the operation status of the drainage pipe network system in the region;

[0012] Step 7, classify the results of the evaluation, locate the key problem areas of the sewage drainage pipe network system, and use equipment to focus on the key problem areas to accurately locate the problems of the pipe network system.

[0013] Further, the main indicators for evaluating the operation status in step 6 include operation risk status, rainwater and sewage mixing status, external water intrusion status, pipe network overflow risk, and centralized sewage collection and treatment rate of the area.

[0014] Further, the information of the drainage pipe involved in step 1 includes but is not limited to drainage pipe type, location, buried depth, flow direction, pipe diameter, and spatial position information.

[0015] Further, the monitoring point nodes proposed in step 3 include primary nodes, secondary nodes, and tertiary nodes.

[0016] Further, the setting method of the monitoring point nodes includes:

[0017] Set the sewage transmission pump station and the sewage inspection well before the sewage treatment plant as a primary node, and set the drainage area served by the primary node as a primary partition;

[0018] Further divide the primary partition, set secondary nodes at the main pipe network or secondary pipe network collection inspection wells in the primary partition, and set the drainage area served by the secondary nodes as a secondary partition;

[0019] Further divide the secondary partition, set tertiary nodes at the secondary branch pipe network collection inspection wells, before and after the river, lake pipe inspection wells, and construction site intensive areas in the secondary partition, and set the drainage area served by the tertiary nodes as a tertiary partition.

[0020] Further, if there are multiple pipelines converging at the sewage transmission pump station or before the sewage treatment plant, set primary nodes at the inspection wells at the ends of each pipeline.

[0021] Further, the drainage information collected in step 3 includes but is not limited to sewage flow, liquid level, and water quality.

[0022] Further, the sewage drainage pipe network water quality and quantity topology graph includes but is not limited to water quality data, water quantity data, pipe network fullness, pipe diameter information, pipe network shape, and drainage flow direction information.

[0023] Further, the device used in step 7 includes but is not limited to CCTV or QV device.

[0024] Compared with the prior art, the present application has the following beneficial effects: through the pipe network survey, the background situation is found out, then through the node water quality and quantity monitoring, the regional key problems are diagnosed, the problem classification weight is determined, the regional problem classification list is formed, the problem points are located through the pipe network detection in the key problem area, thereby guiding the pipe network repair and other drainage pipe network improvement projects.

[0025] The process of the present application is clear, easy to implement, can fully combine the advantages of water quality and quantity monitoring and pipe network detection, form a preliminary diagnosis of the pipe network system through water quality and quantity monitoring, facilitate the master of the drainage pipe network system problem, and through the pipe network detection, the specific problems and points of the pipe network are checked, thereby realizing the rapid diagnosis of the pipe network problem, greatly improving the investigation efficiency, reducing the cost investment, reducing the investigation period, and ensuring the investigation effect. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. The embodiments in the present application and the features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0027] The drainage pipe network system investigation and detection method of the present application comprises the following steps:

[0028] Step 1: Systematic survey is performed on the drainage pipe network, and the information of the drainage pipe, including but not limited to the type, position, buried depth, flow direction, pipe diameter and spatial position information of the drainage pipe, is recorded to prepare a regional rainwater and sewage drainage pipe network system diagram;

[0029] Step 2: Based on the regional rainwater and sewage pipe network system diagram prepared in step 1, the sewage pipe network is generalized to form a sewage drainage pipe topology relationship diagram;

[0030] Step 3: Based on the sewage drainage pipe topology relationship diagram formed in step 2, a monitoring point node is planned for drainage information collection in the drainage pipe network. The drainage information collection point is used to collect drainage information in the drainage pipe network, and the drainage information includes but is not limited to sewage flow, liquid level and water quality.

[0031] Step 4: Based on the monitoring point node planned in step 3, the sewage drainage pipe is divided into zones and numbered respectively;

[0032] Step 5, based on the drainage information collected in step 3, draw a sewage drainage network water quality and quantity topology graph, which includes but is not limited to water quality data, water quantity data, pipe network fullness, pipe diameter information, pipe network shape and drainage flow direction information;

[0033] Step 6, based on the drainage information collected in step 3, evaluate the operation status of the drainage pipe network system in the region;

[0034] Step 7, grade the evaluation results, locate the key problem areas of the sewage drainage pipe network system, and use CCTV or QV equipment and the like to focus on the key problem areas to accurately locate the pipe network system problems.

[0035] In an embodiment, the main indicators for evaluating the operation status in step 6 include operation risk status, rain and sewage mixing status, external water intrusion status, pipe network overflow risk and the centralized sewage collection and treatment rate of the region.

[0036] Preferably, the operation risk status is evaluated in the following manner: when the flow rate v≥0.6 m / s, there is no blockage; when the flow rate v<0.6 m / s, there is a blockage risk.

[0037] Preferably, the evaluation method of the operation risk status further includes calculating the "overload multiple n" and the "flow capacity loss S":

[0038] Overload multiple n=(liquid level Y j -liquid level Y s ) / liquid level Y s under the maximum design fullness;

[0039] Flow capacity loss S=(design flow capacity Q s -monitored flow capacity Q j ) / design flow capacity Q s ;

[0040] When n≥0 and S≥20%, it is judged that there is a blockage; when n≥0 and S<20%, it is judged that there is basically no blockage or the blockage is not serious; when n<0, it needs to be judged according to the actual situation on site.

[0041] Preferably, the rain and sewage mixing status is evaluated in the following manner:

[0042] Q RDII =Q WWF -Q DWF

[0043] η=Q RDII / Q DWF

[0044] wherein:

[0045] Q RDII —rainfall induced inflow infiltration, m 3 / d;

[0046] Q WWF —rain day flow, m 3 / d;

[0047] Q DWF —dry day flow, m 3 / d;

[0048] η—inflow infiltration rate;

[0049] The inflow infiltration rate is used to judge the risk degree of rain day external water invasion, which can reflect the risk degree of mixed connection, when η≤0, it is extremely low risk; 0

[0050] Preferably, the external water invasion condition is evaluated by the following method:

[0051] According to the material conservation, Q k+1 C k+1 = Q k C k + Q z C z + Q w C w

[0052] Qw = (Q k+1 C k+1 - Q k C k - Q z C z ) / C w

[0053] λ = Q w / Q k+1

[0054] Q k+1 —measured total water quantity of pipe network above k+1 section, m 3 / d;

[0055] C k+1 —measured pollutant concentration of pipe network above k+1 section, mg / L;

[0056] Q k —measured total water quantity of pipe network above k section, m 3 / d;

[0057] C k— The measured pollutant concentration of the pipe network above the kth section, mg / L;

[0058] Q z — The measured water quantity of the branch pipe, m 3 / d;

[0059] C z — The pollutant concentration of the branch pipe, mg / L;

[0060] Q w — The external water flow, m 3 / d;

[0061] C w — The pollutant concentration of the external water, generally using the concentration of local underground water or surface water, mg / L;

[0062] λ— The external water infiltration ratio, %.

[0063] The external water infiltration ratio is used to judge the risk degree of external water invasion on dry days, which can reflect the risk degree of pipe network defects. When λ≤20%, it is extremely low risk; 20%<λ≤40%, it is low risk; 40%<λ≤60%, it is medium risk; 60%<λ≤80%, it is high risk; and 80%<λ, it is extremely high risk.

[0064] Preferably, the pipe network overflow risk is evaluated as follows:

[0065] Overflow index R=(H y -H d ) / (H j -H d )

[0066] R— Overflow index;

[0067] H y — Liquid level, m;

[0068] H d — Distance from the top of the pipe to the bottom of the well, m;

[0069] H j — Well depth, m.

[0070] The overflow index is used to judge the risk degree of pipe network overflow. When R≤0, it is no risk; 0

[0071] Preferably, the district sewage centralized collection and treatment rate is evaluated as follows:

[0072] District domestic sewage centralized collection rate θ=(Q w ×C w ) / (P T ×q人 )

[0073] Q w —The amount of wastewater entering the sewage treatment plant in the area;

[0074] C w —Concentration of domestic pollutants entering the sewage treatment plant in the area;

[0075] P T —Total population using water in the area;

[0076] q 人 —Daily emissions of domestic pollutants per capita.

[0077] In one embodiment, the method for setting the monitoring point nodes includes:

[0078] The sewage inspection wells in front of the sewage transmission pump station and sewage treatment plant are set as primary nodes, and the drainage area served by the primary nodes is set as a primary zone. If multiple pipes converge in front of the sewage transmission pump station or sewage treatment plant, a primary node is set at the inspection well at the end of each pipe.

[0079] The primary zones are further divided, and secondary nodes are set at the main or secondary pipeline collection manholes within the primary zones. The drainage areas served by the secondary nodes are set as secondary zones.

[0080] The secondary zones are further divided into tertiary nodes, which are set up in the secondary branch network collection manholes, river crossings, manholes before and after lake pipes, and dense construction sites within the secondary zones. The drainage areas served by the tertiary nodes are set up as tertiary zones.

[0081] I. Monitoring Plan

[0082] By establishing demonstration zones within Wuhan, and based on the method of setting up monitoring points and nodes, combined with administrative plans, a management grid unit was established using the approach of first the main and secondary pipelines, then the branch pipelines, and finally the streets and communities. This grid unit includes primary management grid units S-1, S-2, and S-3, which start from the outfall outside the demonstration zone and trace upstream along the main pipeline, covering the entire catchment area of ​​the primary management grid unit. Secondary management grid units start from the node where the secondary pipeline merges into the main pipeline, and cover the catchment area of ​​the branch pipelines and the pipe networks of the streets and communities they connect to.

[0083] II. Monitoring Site Layout

[0084] To understand the water balance in the area, based on the topological connections of the drainage network and on-site surveys, 27 continuous monitoring points were set up in the main and secondary sewage and stormwater pipes. The specific locations are listed in Table 1.

[0085] Table 1. Statistical Table of Monitoring Points

[0086]

[0087]

[0088] III. Equipment installation

[0089] Based on the monitoring point setting situation, 27 monitoring equipment were set at the monitoring point positions, including 27 online flow meters and 11 SS detectors. The equipment installation situation is shown in Table 2:

[0090] Table 2 Equipment installation statistics

[0091]

[0092]

[0093] IV. Water quantity accounting

[0094] Based on the flow monitoring data of each monitoring point and the population-area estimation results, the water quantity of the construction canal area was accounted. The daily average cumulative flow statistics of each point are shown in Table 3:

[0095] Table 3 Daily average cumulative flow statistics of each monitoring point

[0096]

[0097] Through comparative analysis of the measured flow of each monitoring point, the estimated sewage quantity of each area and the pumping capacity of the pumping station, it is preliminarily inferred that there is an external water intrusion problem in the sewage pipe network of the area, which increases the operation load of the construction canal sewage pumping station, reduces the treatment efficiency and operation benefit of the sewage pumping station.

[0098] V. Evaluation of primary control grid unit

[0099] By monitoring the water quality and quantity of each subarea outlet, combined with the water quality data of the infiltration source, the water quantity and quality balance equation of each level of control grid unit drainage system was established. Based on the water quality and quantity simultaneous equations, the sewage quantity of each subarea, the external water inflow infiltration quantity and the infiltration proportion were calculated.

[0100] The inflow infiltration severity grade of the area was divided and evaluated according to the external water infiltration proportion. The division standard is as follows:

[0101] Very serious: more than 50%

[0102] Serious: 30% to 50%

[0103] Comparatively serious: 15% to 30%

[0104] If the groundwater infiltration quantity of the main pipe is less than 15%, it is considered to be in the normal range and not to be repaired for the time being. The pipe network can be checked in detail according to the order of groundwater infiltration severity grade evaluation.

[0105] According to the monitoring point flow data and COD test results, the inflow and infiltration of the three primary control grid units of the sewage pipe network were analyzed, and the population density and water consumption quota data were used to calculate the theoretical sewage quantity of each area, evaluate the sewage collection rate of each control grid unit, and the analysis results are shown in Table 4.

[0106] Table 4 Results of inflow and infiltration of primary control grid units of sewage pipe network

[0107]

[0108] According to the inflow and infiltration analysis results of the primary control grid units of the sewage pipe network, the infiltration ratios of the primary control grid units S-1, S-2 and S-3 are all greater than 30%, which are serious areas of pipe network infiltration. It is necessary to further identify the topological structure relationship of the pipe network and further identify the key areas of external water infiltration.

[0109] Based on the inflow and infiltration evaluation results of the primary control grid units, the secondary control grid units were refined and quantitatively evaluated, effectively reducing the problem pipe section range and finding out the problem sub-area.

[0110] According to the evaluation results of the sewage collection rate of the primary control grid units, the sewage collection rates of the two primary control grid units S-1 and S-2 in the construction channel area are both low (less than 65%), which needs to accelerate the construction of the sewage collection pipe network in the area, eliminate the blank area of the pipe network, increase the management of drainage permit, reduce the rain and sewage mixed connection phenomenon, and strengthen the maintenance and management of the pipe network to reduce the leakage of the pipe network and improve the sewage collection rate of the pipe network in the construction channel area.

[0111] Six, Conclusion

[0112] 1. Serious invasion of external water, excessive water quantity leading to overload operation of pump station

[0113] According to the monitoring data, the construction channel area is currently divided into three primary control grid units, S-1, S-2 and S-3, with areas of 1.89 km2, 1.9 km2 and 2.59 km2 respectively. According to the inflow and infiltration analysis results of the primary control grid units of the sewage pipe network, the infiltration ratios of the primary control grid units S-1, S-2 and S-3 are all greater than 30%. A large amount of external water invades the sewage pipe network system, indicating that the sewage collection system is closely related to the external water force, and the increased delivery quantity also further damages the health of the pipe network, causing the downstream sewage pump station to increase the delivery quantity and increase the operation load of the pump station. The detailed data is shown in Table 5.

[0114] Table 5 Statistics of daily cumulative flow of each monitoring point in dry season

[0115]

[0116]

[0117] 2. Rainwater and sewage mixed connection problem is prominent, and the pollution load of the receiving water body is increasing

[0118] According to the monitoring scheme, two monitoring devices were arranged on the rainwater pipe network in the construction channel area. Through monitoring, it was found that YS-06 and YS-07 both had dry season outflow during the monitoring period, with daily average flow of 1548.65 m3 and 771.23 m3, respectively; the concentration of SS was 56.79 mg / L and 77.2 mg / L, respectively, and the daily average SS load was 34.98 kg and 54.38 kg, respectively; the average concentration of COD was 169.67 mg / L and 112.54 mg / L, and the daily average COD load was 150.61 kg and 87.91 kg, respectively. The detailed data is shown in Table 6.

[0119] Table 6 Rainwater monitoring point dry season flow and pollution load statistics

[0120] Monitoring point Average daily flow Average SS concentration Daily SS load Average COD concentration Daily COD load YS-06 1548.65 56.79 34.98 169.67 150.61 YS-07 771.23 77.2 54.38 112.54 87.91

[0121] The pollutants carried by the rainwater system into the downstream receiving water body (construction channel) increase the demand for additional pollutant purification and transmission of the construction channel, which is prone to cause point source pollution of the receiving water body.

[0122] 3. Pipe network collection rate and coverage degree need to be improved

[0123] According to the inflow and infiltration analysis results of the area sewage pipe network, the sewage collection rates of first-level pipe control grid units S-1 and S-2 were 60.85% and 41.04%, respectively, and the pipe network collection rate was less than 70%. In the second-level pipe control grid units, except WS-10 and WS-11, the collection rates of other second-level pipe control grid units did not reach 100%, among which the sewage collection rate of WS-05 pipe control unit was only 42.79%, less than 50%. The sewage collection rate of first-level pipe control grid unit S-3 was 100%, but the pipe network collection rate of its second-level pipe control unit WS-19 was 62.22%, less than 70%, indicating that the pipe network collection rate or coverage degree of this area needs to be improved. The detailed data is shown in Table 7.

[0124] Table 7 Statistics of sewage collection rate in the area

[0125]

[0126] 4. Full pipe flow pipe proportion is high, and drainage capacity is insufficient

[0127] According to the pipe network layout and field investigation, the pipe diameter of the sewage pipe in this area is concentrated between 0.4m and 1.5m, among which the main pipe diameter is 1.2m to 1.5m, and the secondary pipe diameter is 0.4m to 0.6m. According to the "Code for Design of Outdoor Drainage", as shown in Table 8.

[0128] Table 8: Allowable maximum fullness table for different pipe diameters (D) or underground channel height (H)

[0129] No. Pipe diameter (D) or depth of covered channel (H) (mm) Maximum fullness (h / D) 1 200～300 0.55 2 350～450 0.65 3 500～900 0.70 4 ≥1000 0.75

[0130] Through monitoring data, it is known that the fullness of 17 monitoring points among the 23 monitoring points of the sewage system exceeds the provisions of the "Code for Design of Outdoor Drainage", and the full pipe operation time of 11 monitoring points is more than 10 hours, the pipe network operation pressure is large, and the detailed data is shown in Table 9.

[0131] Table 9: Full pipe operation time statistics table of each monitoring point in the area

[0132] No. Monitoring point Average liquid level Pipe diameter Average fullness Full pipe operation time Exceeding standard 1 WS-01 0.46 0.6 0.77 8.89 Yes 2 WS-02 0.5 0.6 0.83 10.22 Yes 3 WS-03 1.08 1.2 0.9 11.02 Yes 4 WS-04 0.25 0.5 0.5 2.23 No 5 WS-05 0.28 0.4 0.7 10.47 Yes 6 WS-06 0.37 0.4 0.9 14.51 Yes 7 WS-07 1.39 1.5 0.92 16.87 Yes 8 WS-08 1.77 1.8 0.77 20.79 Yes 9 WS-09 1.61 1.8 0.89 14.27 Yes 10 WS-10 0.4 0.4 1 24 Yes 11 WS-11 0.29 0.4 0.7 0.82 Yes 12 WS-12 0.2 0.5 0.4 0.99 No 13 WS-13 0.28 0.4 0.7 0.00 Yes 14 WS-14 0.39 0.40 0.98 16.63 Yes 15 WS-15 0.22 0.40 0.55 0.91 No 16 WS-17 0.39 0.40 0.98 19.81 Yes 17 WS-18 0.44 0.50 0.88 0.01 Yes 18 WS-19 0.48 0.60 0.8 0.01 Yes 19 WS-20 0.26 0.40 0.65 0.00 No 20 WS-21 0.20 0.40 0.5 1.38 No 21 WS-22 0.40 0.40 1 24.00 Yes 22 WS-23 0.32 0.40 0.8 9.21 Yes 23 WS-24 0.28 0.50 0.56 0.04 No

[0133] 5. Low flow rate and poor drainage

[0134] In order to ensure that no accumulation occurs in the pipeline, China determines the minimum flow rate of sewage pipe to be 0.6m / s according to experimental results and operation experience. Through monitoring data analysis, the average flow rate of 23 monitoring points during the monitoring period is distributed between 0.04m / s and 0.24m / s, and the average value of the maximum flow rate of each monitoring point in seven days is distributed between 0.08m / s and 0.8m / s. Except for WS-19 monitoring point, the minimum flow rate guarantee value of the remaining monitoring points is less than 0.6m / s. In addition, the maximum flow rate value of each monitoring point during the monitoring period is selected, and only the maximum flow rate of four points of WS-04, WS-10, WS-19 and WS-21 among the 23 monitoring points exceeds 0.6m / s, and the maximum flow rate of the remaining 19 monitoring points does not meet the requirements, and the problem of poor drainage is more serious, and the detailed data is shown in Table 10.

[0135] Table 10: Flow rate statistics table of each monitoring point in the area

[0136] No. Monitoring point Average flow velocity Maximum flow velocity Seven-day average maximum flow velocity 1 WS-01 0.21 0.46 0.40 2 WS-02 0.08 0.59 0.29 3 WS-03 0.08 0.37 0.20 4 WS-04 0.09 0.64 0.31 5 WS-05 0.12 0.40 0.25 6 WS-06 0.18 0.44 0.36 7 WS-07 0.08 0.37 0.22 8 WS-08 0.22 0.47 0.43 9 WS-09 0.15 0.37 0.33 10 WS-10 0.14 0.61 0.42 11 WS-11 0.06 0.35 0.29 12 WS-12 0.15 0.49 0.37 13 WS-13 0.04 0.35 0.22 14 WS-14 0.13 0.43 0.32 15 WS-15 0.09 0.29 0.16 16 WS-17 0.10 0.48 0.34 17 WS-18 0.04 0.14 0.12 18 WS-19 0.20 0.97 0.80 19 WS-20 0.24 0.44 0.42 20 WS-21 0.17 0.60 0.55 21 WS-22 0.04 0.09 0.08 22 WS-23 0.08 0.29 0.26 23 WS-24 0.21 0.45 0.40

[0137] 6. The problem of pipe network accumulation is serious, which affects the water carrying capacity of the pipe network

[0138] According to the field investigation and survey, each monitoring point presents the state of silt deposition in different degrees, the ratio of silt covering thickness to pipe diameter is distributed between 6.67% and 75%, the silt deposition of the pipeline affects the water area of the pipeline, in addition, the silt deposition of the pipeline also affects the roughness of the pipeline wall and then affects the flow rate of the pipeline, and comprehensively affects the water capacity of the pipeline. The detailed data is shown in Table 11.

[0139] Table 11: Pipe silt deposition statistics table of each monitoring point in the area

[0140]

[0141]

[0142] It is apparent to those skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments, and that the application can be implemented in other particular forms without departing from the spirit or essential characteristics of the application. The embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A method for detecting and investigating a separate flow sewer network system, characterized in that: The method comprises the following steps: Step 1: conducting a systematic survey on the drainage network, recording the information of the drainage pipeline, and preparing a regional rainwater and sewage drainage network system diagram; Step 2: based on the regional rainwater and sewage drainage network system diagram prepared in step 1, generalizing the sewage pipeline network to form a sewage drainage pipeline topology relationship diagram; Step 3: based on the sewage drainage pipeline topology relationship diagram formed in step 2, planning monitoring point nodes for collecting drainage information in the drainage network; Step 4: based on the monitoring point nodes planned in step 3, partitioning the sewage drainage pipeline, and numbering them respectively; Step 5: based on the drainage information collected in step 3, drawing a sewage drainage network water quality and quantity topology relationship diagram; Step 6: based on the drainage information collected in step 3, evaluating the operation status of the regional drainage network system; Step 7: classifying the evaluation results, locating the key problem areas of the sewage drainage network system, and using equipment to conduct key investigation on the key problem areas to accurately locate the problems of the pipeline network system; The main indicators for evaluating the operation status in step 6 include operation risk status, rainwater and sewage mixing status, external water intrusion status, pipeline network overflow risk, and regional sewage centralized collection and treatment rate; The evaluation of the operation risk status adopts the following method: when the flow rate v is greater than or equal to 0.6 m / s, there is no blockage; when the flow rate v is less than 0.6 m / s, there is a blockage risk; The evaluation method of the operation risk status further includes calculating the "overload factor n" and the "flow capacity loss S": Overload factor n = (liquid level Yj - liquid level Ys under maximum design fullness) / liquid level Ys under maximum design fullness; Flow capacity loss S = (design flow capacity Qs - monitored flow capacity Qj) / design flow capacity Qs; When n is greater than or equal to 0 and S is greater than or equal to 20%, it is judged that there is a blockage; when n is greater than or equal to 0 and S is less than 20%, it is judged that there is basically no blockage or the blockage is not serious; when n is less than 0, it needs to be judged according to the actual situation on site; The evaluation method of the external water intrusion status is as follows: According to the conservation of mass, Q k+1 C k+1 = Q k C k + Q z C z + Q w C w Qw= (Q k+1 C k+1 -Q k C k -Q z C z ) / C w λ = Q w / Q k+1 Q k+1 — the total water quantity of the pipe network above the k+1th section, m 3 / d; C k+1 — the k+1th pipe network measured pollutant concentration, mg / L; Q k — the total water quantity measured in the pipe network of the kth section, m 3 / d; C k — the kth section above pipe network measured pollutant concentration, mg / L; Q z — measured water quantity of branch pipe, m 3 / d; C z —branch pipe pollutant concentration, mg / L; Q w — external water flow, m 3 / d; C w - concentration of foreign water pollutants, generally the concentration of local groundwater or surface water, mg / L; λ—external water infiltration ratio, %; The external water infiltration ratio is used to judge the risk degree of external water intrusion in dry weather, which can reflect the risk degree of pipeline network defects. When λ is less than or equal to 20%, it is extremely low risk; when 20% < λ ≤ 40%, it is low risk; when 40% < λ ≤ 60%, it is medium risk; when 60% < λ ≤ 80%, it is high risk; and when 80% < λ, it is extremely high risk.

2. The method of claim 1, wherein: The information of the drainage pipeline involved in step 1 includes but is not limited to the type, position, buried depth, flow direction, pipe diameter and spatial position information of the drainage pipeline.

3. The method of claim 1, wherein: The monitoring point nodes planned in step 3 include primary nodes, secondary nodes and tertiary nodes.

4. The method of claim 3, wherein: The setting method of the monitoring point nodes includes: setting the sewage transmission pump station and the sewage inspection well before the sewage treatment plant as primary nodes, and setting the drainage area served by the primary nodes as a primary partition; further dividing the primary partition, setting secondary nodes at the inspection wells of the main pipeline network or secondary pipeline network in the primary partition, and setting the drainage area served by the secondary nodes as a secondary partition; The secondary partition is further divided, and the secondary branch network in the secondary partition collects inspection wells, rivers, lake pipe front and back inspection wells, and construction site intensive area to set a third node. The drainage area served by the third node is set as a third partition.

5. The method of claim 4, wherein: If multiple pipelines are merged before the sewage transmission pump station or the sewage treatment plant, a first node is set in the inspection well at the end of each pipeline.

6. The method of claim 1, wherein: The drainage information collected in step 3 includes but is not limited to sewage flow, liquid level and water quality.

7. The method of claim 1, wherein: The sewage drainage pipe network water quality and quantity topology graph includes but is not limited to water quality data, water quantity data, pipe network fullness, pipe diameter information, pipe network shape and drainage flow direction information.

8. The method of claim 1, wherein: The equipment used in step 7 includes but is not limited to CCTV or QV equipment.

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