Method for optimizing rainwater pipe system designed based on rainwater management model and storage device
Technical Field
The invention relates to the technical field of municipal engineering, in particular to a method for optimizing a rainwater pipe system designed based on a rainwater management model and storage equipment.
Background
The reasoning formula method is based on water quantity balance, combines rainfall intensity data and catchment area characteristics, predicts the high peak runoff under the rainfall event, and is used as the design flow of the rainwater pipe canal. The reasoning formula considers the influence of the length and the gradient of the water flow path of the catchment area (namely, the calculation effect of rainfall) by utilizing the catchment time, and considers the rainfall loss by utilizing the runoff coefficient. The method is simple to use and is a common method for designing and calculating the rainwater pipe system.
When the conditions of time-varying rainfall, rainfall loss change and the like are considered in the running process of the rainwater pipe canal system, the reasoning formula method is not applicable any more, and the rainwater management model (SWMM) software simulation is usually adopted at the moment, wherein the simulation software comprises EPA SWMM, MIKE SWMM, PCWMM, XPSWMM and the like.
However, in many cases, an inference formula method is still needed for the consideration of simple calculation, so how to simulate the inference formula method based on a rainwater management model, so that a rainwater pipe-duct system designed based on the inference formula method can be widely applied, and a technical problem to be solved is needed.
Disclosure of Invention
Therefore, a method for optimizing a rainwater pipe system designed based on a rainwater management model is needed to be provided, so as to solve the technical problem that the rainwater pipe system designed based on the rainwater management model in the prior art cannot simulate an inference formula method, so that the application range of the rainwater pipe system is limited. The specific technical scheme is as follows:
a method of optimizing a storm drain system designed based on a storm drain management model, comprising the steps of:
dividing a drainage basin and a pipe and channel routing line;
dividing a design pipe section;
dividing and calculating the sub-catchment area of each designed pipe section;
setting the sub-catchment area attribute;
calculating from an upstream pipe section to a downstream pipe section according to a preset rule;
and optimizing the rainwater pipe system according to the calculation result.
Further, the calculation from the upstream pipe section to the downstream pipe section according to a preset rule specifically includes the steps of:
step S201: calculating the sub-catchment area at the starting end of the rainwater pipe canal system to obtain ground catchment time or directly obtaining the ground catchment time according to historical experience;
step S202: calculating the rainfall intensity of the sub-catchment area according to an IDF curve or an rainstorm intensity formula, and assigning the rainfall intensity to an rainstorm intensity time sequence as a constant value;
step S203: automatically calculating the surface runoff at the outlet of the sub-catchment area by rainwater management model simulation software;
step S204: calculating the flow rate meeting the preset requirement by adjusting the diameter of the downstream designed pipe section and the bottom elevation of the junction;
step S205: calculating the popularity time in the design pipe section;
step S206: when the sub-catchment area is not at the starting end of the rainwater canal system, selecting the catchment time from the furthest point to the outlet as the catchment time for simulating the sub-catchment area, and jumping to step S202.
Further, the step S204 specifically includes the steps of:
step S301: setting the diameter of a downstream designed pipe section and the bottom elevation of a junction;
step S302: calculating the flow velocity of the designed pipe section;
step S303: and judging whether the designed flow rate meets the preset requirement, if not, skipping to the step S301, and if so, executing the step S205.
Further, the step S201 of calculating the ground water collecting time specifically includes the steps of:
the water collecting time T consists of ground water collecting time T1 and the circulation time T2 required by rainwater to flow to the designed section in the pipeline:
T=t1+m*t2
m is a reduction coefficient or a volume utilization coefficient.
Further, the setting of the sub-catchment area attribute specifically includes the steps of:
the impermeable percentage sets up to the runoff coefficient value, and no hole is deposited water and is not impermeably percent and set up to 100, and infiltration area and impermeable area hole deposit depth of water set up to zero, and slope and width are given arbitrary numerical value, and infiltration and impermeabilization Manning roughness coefficient adopt 0, utilize the Horton option of oozing, make its biggest and minimum infiltration rate the same, and the numerical value that is not less than rainfall intensity is got to the biggest infiltration rate.
In order to solve the technical problem, the storage device is further provided, and the specific technical scheme is as follows:
a storage device having stored therein a set of instructions for performing:
dividing a drainage basin and a pipe and channel routing line;
dividing a design pipe section;
dividing and calculating the sub-catchment area of each designed pipe section;
setting the sub-catchment area attribute;
calculating from an upstream pipe section to a downstream pipe section according to a preset rule;
and optimizing the rainwater pipe system according to the calculation result.
Further, the set of instructions is further for performing:
the method comprises the following steps of calculating from an upstream pipe section to a downstream pipe section according to a preset rule, and specifically comprises the following steps:
step S201: calculating the sub-catchment area at the starting end of the rainwater pipe canal system to obtain ground catchment time or directly obtaining the ground catchment time according to historical experience;
step S202: calculating the rainfall intensity of the sub-catchment area according to an IDF curve or an rainstorm intensity formula, and assigning the rainfall intensity to an rainstorm intensity time sequence as a constant value;
step S203: automatically calculating the surface runoff at the outlet of the sub-catchment area by rainwater management model simulation software;
step S204: calculating the flow rate meeting the preset requirement by adjusting the diameter of the downstream designed pipe section and the bottom elevation of the junction;
step S205: calculating the popularity time in the design pipe section;
step S206: when the sub-catchment area is not at the starting end of the rainwater canal system, selecting the catchment time from the furthest point to the outlet as the catchment time for simulating the sub-catchment area, and jumping to step S202.
Further, the set of instructions is further for performing:
the step S204 further includes:
step S301: setting the diameter of a downstream designed pipe section and the bottom elevation of a junction;
step S302: calculating the flow velocity of the designed pipe section;
step S303: and judging whether the designed flow rate meets the preset requirement, if not, skipping to the step S301, and if so, executing the step S205.
Further, the set of instructions is further for performing:
the step S201 of calculating the ground water collecting time further includes the steps of:
the water collecting time T consists of ground water collecting time T1 and the circulation time T2 required by rainwater to flow to the designed section in the pipeline:
T=t1+m*t2
m is a reduction coefficient or a volume utilization coefficient.
Further, the set of instructions is further for performing:
the method specifically comprises the following steps of:
the impermeable percentage sets up to the runoff coefficient value, and no hole is deposited water and is not impermeably percent and set up to 100, and infiltration area and impermeable area hole deposit depth of water set up to zero, and slope and width are given arbitrary numerical value, and infiltration and impermeabilization Manning roughness coefficient adopt 0, utilize the Horton option of oozing, make its biggest and minimum infiltration rate the same, and the numerical value that is not less than rainfall intensity is got to the biggest infiltration rate.
The invention has the beneficial effects that: a method of optimizing a storm drain system designed based on a storm drain management model, comprising the steps of: dividing a drainage basin and a pipe and channel routing line; dividing a design pipe section; dividing and calculating the sub-catchment area of each designed pipe section; setting the sub catchment area attribute so as to obtain the same runoff coefficient used in the reasoning formula method; calculating from an upstream pipe section to a downstream pipe section according to a preset rule; and optimizing the rainwater pipe system according to the calculation result. The rainwater pipe channel system optimized by the method has the conditions of considering time-varying rainfall, rainfall loss change and the like brought by a rainwater management model, and has the function of reproducing the simulation formula method without additionally increasing any software function, so that the optimized rainwater pipe channel system has a more diversified calculation mode and can be widely applied.
Drawings
FIG. 1 is a flow chart of a method of optimizing a storm drain system based on a storm drain management model design according to an embodiment;
FIG. 2 is a flowchart illustrating a calculation performed from an upstream pipe segment to a downstream pipe segment according to a predetermined rule according to an embodiment;
FIG. 3 is a flow chart of the embodiment for calculating a flow rate that meets a predetermined requirement by adjusting the diameter of the downstream design pipe section and the elevation of the bottom at the junction;
fig. 4 is a block diagram of a storage device according to an embodiment.
Description of reference numerals:
400. a storage device.
Detailed Description
To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.
Referring to fig. 1 to 3, in the present embodiment, a method for optimizing a rainwater raceway system designed based on a rainwater management model can be applied to a storage device, including but not limited to: personal computers, servers, general purpose computers, special purpose computers, network devices, embedded devices, programmable devices, intelligent mobile terminals, etc. The specific technical scheme is as follows:
step S101: dividing drainage basin and canal alignment. Drainage basin: the drainage zone boundary is the planned boundary of the drainage system, and drainage basins are divided according to the vertical planning of terrains and cities in the drainage zone boundary. Pipe canal line setting: various factors are comprehensively considered for the straight pipe and the main pipe, so that the proposed route can utilize favorable conditions according to local conditions and avoid unfavorable conditions.
Step S102: and dividing a design pipe section.
Step S103: and dividing and calculating the sub-catchment area of each designed pipe section. The sub-catchment area is the area of the ground where the pipe sections are designed to collect and drain rainwater.
Step S104: and setting the sub-catchment area attribute.
Step S105: and calculating from the upstream pipe section to the downstream pipe section according to a preset rule.
Step S106: and optimizing the rainwater pipe system according to the calculation result. In this step, since the formula method can be simulated for calculation in steps S101 to S105, the rainwater pipe system can be optimized accordingly, so that the rainwater pipe system not only has the conditions of time-varying rainfall, rainfall loss variation and the like brought by the rainwater management model, but also has the function of reproducing the simulation formula method, and the simulation formula method can be reproduced without additionally adding any software function, so that the optimized rainwater pipe system has a more diversified calculation method and can be more widely applied.
As shown in fig. 2, the step S105 specifically includes the steps of:
step S201: calculating the sub-catchment area at the starting end of the rainwater pipe canal system to obtain ground catchment time or directly obtaining the ground catchment time according to historical experience;
step S202: calculating the rainfall intensity of the sub-catchment area according to an IDF curve or an rainstorm intensity formula, and assigning the rainfall intensity to an rainstorm intensity time sequence by taking the rainfall intensity as a constant value, wherein each place of the rainstorm intensity formula has a own rainstorm intensity formula;
step S203: automatically calculating the surface runoff at the outlet of the sub-catchment area by rainwater management model simulation software;
step S204: calculating a flow rate that meets a preset requirement (the preset requirement is determined according to a design specification) by adjusting the diameter of the downstream designed pipe section and the bottom elevation of a junction (a junction of an upstream designed pipe and a downstream related pipe, which are connected);
step S205: calculating the popularity time in the design pipe section; the prevalence time is the design tube length divided by the flow rate.
Step S206: when the sub-catchment area is not at the beginning of the storm drain system (i.e. when its outlet is not entering the initial pipe section, the storm drain system in this embodiment will identify the pipe section that is not the beginning, i.e. any pipe section in the storm drain), then the catchment time from the furthest point in water to the outlet is selected as the catchment time for the simulation of the sub-catchment area (where the catchment time on the ground represents the prevailing time of rainfall runoff from the furthest point in the catchment area to the downstream outlet of the basin, the furthest point in water is not necessarily the longest point because the time of the flow in the diffuse and ditch depends on the characteristics of the ground surface.
As shown in fig. 3, the step S204 further includes the steps of:
step S301: setting the diameter of a downstream designed pipe section and the bottom elevation of a junction;
step S302: calculating the flow velocity of the designed pipe section;
step S303: and judging whether the designed flow rate meets the preset requirement, if not, skipping to the step S301, and if so, executing the step S205.
Wherein the setting of the sub-catchment area attribute specifically further comprises the steps of:
the correct runoff coefficient value is obtained by reasonably setting a main input attribute setting mode in the rainwater management model. For example, in the SWMM software to set the percent impermeability to the runoff coefficient value, the following parameter settings will be used: the percentage of water impermeability without potholes is set to 100; the depth of the pit water with the penetration area and the non-penetration area is set to be zero; the gradient and the width can be given with any numerical value, the penetration and imperviousness Manning roughness coefficient adopts 0, when the Manning roughness coefficient is 0, all excessive rainfall (effective rainfall or clean rainfall) of each time step length is simply converted into instantaneous runoff, and the water storage or lag effect of surface diffuse flow is ignored; the maximum infiltration rate and the minimum infiltration rate are the same by using the Horton infiltration option, namely the change of the infiltration rate along with time is ignored in the whole calculation, and the maximum infiltration rate is taken as the rainfall loss (the maximum infiltration rate can be not less than the value of the rainfall intensity, so that the rainfall in the infiltration area is completely converted into the rainfall loss). The same runoff coefficient used in the inference formula method can be obtained through the steps, and the same runoff coefficient refers to the ratio of the ground runoff to the total rainfall, so that the ground runoff can be calculated.
The calculation of the ground catchment time specifically comprises the following steps:
the water collecting time T consists of ground water collecting time T1 and the circulation time T2 required by rainwater to flow to the designed section in the pipeline:
T=t1+m*t2
m is a reduction coefficient or a volume utilization coefficient.
If the ground water collecting time is obtained according to historical experience, the method specifically comprises the following steps: in the method, the sub-catchment area at the most upstream of a rainwater pipe canal system is calculated by adopting given empirical ground catchment time or ground catchment time calculated by a formula in rainfall intensity calculation, and usually in areas with high development degree, high impermeability and dense rainwater port distribution, the catchment time is usually 5-8 min; the land parcel development intensity is low, the building density is small, the terrain is flat, the catchment area is large, and the rainwater inlet is arranged in a sparse area, generally 10-15 min; a sub-catchment area inflow point is arranged in the middle of the rainwater pipe canal system, and the maximum water collecting time in different branch pipe canals at the upstream of the inflow point is used as the water collecting time of the sub-catchment area.
In step S202, the time series of the rainstorm intensity adopts a constant rainstorm intensity, which is calculated by the rainstorm intensity formula according to the design recurrence period and the water collecting time determined above; according to the ultimate strength theory, the total duration of the rainstorm intensity time series should be greater than the total catchment time in the service area.
For simulating a reasoning formula, the main input attribute setting of the rain gauge comprises the following steps: the rainfall data type adopts 'rainstorm intensity'; the recording time interval may be set to "1 minute"; the rainfall data source can adopt a time sequence or a file form, if the rainfall intensity is stored in a file, the file name storing the rainfall data needs to be input, and different rain gauges (the rainfall time sequences adopted by the rain gauges are different) can be adopted for different sub-catchment areas for reliably simulating surface runoff.
In step S204, the main input parameters of the junction are: the level of the inner bottom, the depth to the surface of the ground. Because the inner bottom elevation of a junction (the junction refers to the junction of an upstream designed pipeline and a downstream designed pipeline, and the two pipelines are connected) in some rainwater management model simulation software is an output result in simulation calculation instead of a known parameter, the software needs to be operated for many times to obtain the inner bottom elevation through trial calculation. The main input parameters of the pipe duct are: the name of the water inlet junction, the name of the water outlet junction, the offset of the inner bottom of the water inlet junction, the offset of the inner bottom of the water outlet junction, the length of the canal, the Manning roughness coefficient (note that the Manning roughness coefficient of the canal is different from the Manning roughness coefficient of the sub-junction area), the geometric dimension of the cross section and the like. The geometric dimension of the cross section is an output result in the simulation calculation instead of a known parameter, and software needs to be operated for many times to be obtained through trial calculation.
A method of optimizing a storm drain system designed based on a storm drain management model, comprising the steps of: dividing a drainage basin and a pipe and channel routing line; dividing a design pipe section; dividing and calculating the sub-catchment area of each designed pipe section; setting the sub catchment area attribute so as to obtain the same runoff coefficient used in the reasoning formula method; calculating from an upstream pipe section to a downstream pipe section according to a preset rule; and optimizing the rainwater pipe system according to the calculation result. The rainwater pipe channel system optimized by the method has the conditions of considering time-varying rainfall, rainfall loss change and the like brought by a rainwater management model, and has the function of reproducing the simulation formula method without additionally increasing any software function, so that the optimized rainwater pipe channel system has a more diversified calculation mode and can be widely applied.
Referring to fig. 4, in the present embodiment, a memory device 400 is implemented as follows:
a storage device 400 having stored therein a set of instructions for performing: any of the above mentioned steps of a method of optimizing a storm drain system designed based on a storm drain management model.
It should be noted that, although the above embodiments have been described herein, the invention is not limited thereto. Therefore, based on the innovative concepts of the present invention, the technical solutions of the present invention can be directly or indirectly applied to other related technical fields by making changes and modifications to the embodiments described herein, or by using equivalent structures or equivalent processes performed in the content of the present specification and the attached drawings, which are included in the scope of the present invention.