A method for determining drainage flow of a drainage pump station

Abstract

The present invention discloses a method for determining the drainage flow of a drainage pump station, comprising the following steps: step 1, confirming the flow process boundary of the upstream of the flooded area during the flood and the water level process boundary of the downstream of the flooded area during the flood; step 2, determining the starting water level value of the flooded area; calculating the corresponding channel flow rate under different inland river water levels in the flooded area; step 3, selecting a number of drainage flow values, and calculating the inland river water level-inland river volume relationship curve under different pump discharge flow rates; step 4, obtaining the highest inland river water level corresponding to each drainage flow value; step 5, comprehensively considering and selecting the best solution, the pump discharge flow in the solution is the drainage flow value of the drainage pump station. The present invention proposes an efficient and simple pump station scale design method, which can avoid the phenomenon that the upstream flooded area occurs waterlogging, while the drainage pump station downstream of the flooded area cannot operate at full load during the pump station design stage.

Description

Technical Field

[0001] The present invention relates to the field of drainage flow scale design of a drainage pump station, and more specifically, to a method for determining the drainage flow of a drainage pump station. Background Art

[0002] In the actual operation of existing drainage pump stations, it often happens that the water level of rivers and creeks in the upstream flooded areas is high, causing urban waterlogging accidents, while the drainage pump stations downstream of the flooded areas are unable to drain at full capacity, greatly reducing the drainage effect of the pump stations.

[0003] By analyzing the causes, it was found that the main reason why the drainage pump station could not operate according to the designed flow rate was that the drainage pump station often used the "Pinghu Method" to determine the design scale of the pump station during the design stage. This method regards the river, lake, storage lake and other storage and drainage facilities as a whole, and calculates the drainage process of the entire water system according to the water balance formula. This method can more accurately calculate the river storage characteristics and peak shaving effect, but this method does not take into account the flow of water bodies. When the flow capacity of the connecting river between the flooded area and the pump station is insufficient, the pump station will be unable to drain at full load. At present, there is no relevant technology to solve this kind of problem. Summary of the invention

[0004] In order to achieve these purposes and other advantages according to the present invention, a method for determining the drainage flow of a drainage pump station is provided, comprising the following steps:

[0005] Step 1: Confirm the flow process boundary of the upstream of the waterlogged area during the flood period and the water level process boundary of the downstream of the waterlogged area during the flood period;

[0006] Step 2: determine the water level of the inner river in the flood-prone area before rainfall, i.e., the starting water level; calculate the corresponding channel flow rate under different inner river water levels in the flood-prone area;

[0007] Step 3: Select several drainage flow values, and calculate the relationship curve between the inland river water level and the inland river volume under different pumping flow rates according to the inland river water level, the outer river water level, the corresponding channel flow rate under different inland river water levels, and the discharge gate flow, the pumping flow, and the net rain flow into the inland river;

[0008] Step 4: According to the relationship curve between the inland river water level and the inland river volume under different drainage flow values, the highest inland river water level corresponding to each drainage flow value is obtained;

[0009] Step 5: Comprehensively consider the highest inland river water level corresponding to each drainage flow value and the cost of achieving the drainage flow value, and select the best plan. The pump discharge flow in this plan is the drainage flow value of this drainage pumping station.

[0010] According to a preferred embodiment of the present invention, in the method for determining the design scale of the drainage pump station, in step 3, the flow capacity of the channel corresponding to different water levels in the flooded area is calculated using the following formula:

[0011]

[0012] Among them, L is the length of the drainage channel, B is the width of the drainage channel, j is the bottom slope of the drainage channel, n is the channel roughness, R is the wetted perimeter, v is the kinematic viscosity, and U is the flow velocity of the drainage channel in the flooded area.

[0013] According to a preferred embodiment of the present invention, in the method for determining the design scale of the drainage pump station, in the step 2, the drainage starting water level value is determined based on the low water level of the river landscape and the safe water level.

[0014] According to a preferred embodiment of the present invention, in the method for determining the design scale of a drainage pump station, the following operation needs to be performed before step one: determining the drainage standard for the flood-prone area.

[0015] According to a preferred embodiment of the present invention, in the method for determining the design scale of the drainage pump station, in the step 3, according to the inland river water level value, the outer river water level value, the corresponding channel flow rate under different inland river water levels, and in combination with the discharge gate flow, the pump discharge flow and the net rain flow into the inland river, the inland river water level-inland river volume relationship curve under different pump discharge flow rates is calculated, which specifically includes the following steps:

[0016] Step S3-1, determining whether the inland river water level h in the i-th period is greater than or equal to the inland river water level value;

[0017] Step S3-2: If yes, the discharge flow Q=0;

[0018] If not, continue to execute step S3-3;

[0019] Step S3-3, determining whether the outer river water level H in the i-th period is greater than or equal to the inner river water level h;

[0020] Step S3-4, if yes, start the water pump to discharge the water from the inner river to the outer river, and compare the pump discharge flow rate of the water pump with the flow rate value of the drainage channel, and take the smaller one as the discharge flow rate Q;

[0021] If not, the gate is opened to discharge the water from the inner river to the outer river, and the designed discharge capacity of the gate is compared with the flow rate of the channel, and the smaller one is taken as the discharge flow Q;

[0022] Step S3-5, calculating the water volume change ΔV during the time period;

[0023] Step S3-6, calculate the volume V of the inland river i+1 ;

[0024] Step S3-7, listing the inland river water level-inland river volume corresponding to different times, thereby obtaining an inland river water level-inland river volume relationship curve;

[0025] Step S3-8, change the pump discharge flow rate, and repeat the above steps S3-1 to S3-7 to obtain the inland river water level-inland river volume relationship curve under different pump discharge flow rates.

[0026] According to a preferred embodiment of the present invention, in the method for determining the design scale of the drainage pump station, in step S3-5, the following formula is used to calculate the time period change water volume ΔV:

[0027] ΔV=Q*Δt+Qrainfall*Δt Formula (2)

[0028] Among them, ΔV is the change in the volume of the river water body, Q is the outflow of the river, and Q 降雨 is the net rainfall flow into the river, and Δt is the time step.

[0029] According to a preferred embodiment of the present invention, in the method for determining the design scale of the drainage pump station, in step S3-6, the volume of the inland river V is calculated using the following formula: i+1 ;

[0030] V i+1 =V i +ΔV Formula (3)

[0031] Among them, V i Represents the volume of the inland river at time i.

[0032] The present invention includes at least the following beneficial effects: the present invention proposes an efficient and simple pump station scale design method, which can accurately calculate the drainage flow value of the drainage pump station, thereby avoiding waterlogging upstream during the pump station design stage, while the drainage pump station downstream of the flooded area cannot drain at full load.

[0033] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic flow chart of the efficient and simple pump station scale design method in the present invention.

[0035] Figure 2 It is a schematic diagram of the calculation process of the inland river water level-inland river volume relationship curve under different pump discharge rates in the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0037] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0038] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0039] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0040] Example 1

[0041] An embodiment of the present invention provides a method for determining the drainage flow of a drainage pump station, comprising the following steps:

[0042] Step 1: Confirm the flow process boundary of the upstream of the waterlogged area during the flood period and the water level process boundary of the downstream of the waterlogged area during the flood period;

[0043] Step 2: determine the water level of the inner river in the flood-prone area before rainfall, i.e., the starting water level; calculate the corresponding channel flow rate under different inner river water levels in the flood-prone area;

[0044] Step 3: Select several drainage flow values, and calculate the relationship curve between the inland river water level and the inland river volume under different pumping flow rates according to the inland river water level, the outer river water level, the corresponding channel flow rate under different inland river water levels, and the discharge gate flow, the pumping flow, and the net rain flow into the inland river;

[0045] Step 4: According to the relationship curve between the inland river water level and the inland river volume under different drainage flow values, the highest inland river water level corresponding to each drainage flow value is obtained;

[0046] Step 5: Comprehensively consider the highest inland river water level corresponding to each drainage flow value and the cost of achieving the drainage flow value, and select the best plan. The pump discharge flow in this plan is the drainage flow value of this drainage pumping station.

[0047] According to a preferred embodiment of the present invention, in the method for determining the design scale of the drainage pump station, in step 3, the flow capacity of the channel corresponding to different water levels in the flooded area is calculated using the following formula:

[0048]

[0049] Among them, L is the length of the drainage channel, B is the width of the drainage channel, j is the bottom slope of the drainage channel, n is the channel roughness, R is the wetted perimeter, v is the kinematic viscosity, and U is the flow velocity of the drainage channel in the flooded area.

[0050] According to a preferred embodiment of the present invention, in the method for determining the design scale of the drainage pump station, in the step 2, the drainage starting water level value is determined based on the low water level of the river landscape and the safe water level.

[0051] According to a preferred embodiment of the present invention, in the method for determining the design scale of a drainage pump station, the following operation needs to be performed before step one: determining the drainage standard for the flood-prone area.

[0052] According to a preferred embodiment of the present invention, in the method for determining the design scale of the drainage pump station, in the step 3, according to the inland river water level value, the outer river water level value, the corresponding channel flow rate under different inland river water levels, and in combination with the discharge gate flow, the pump discharge flow and the net rain flow into the inland river, the inland river water level-inland river volume relationship curve under different pump discharge flow rates is calculated, which specifically includes the following steps:

[0053] Step S3-1, determining whether the inland river water level h in the i-th period is greater than or equal to the inland river water level value;

[0054] Step S3-2: If yes, the discharge flow Q=0;

[0055] If not, continue to execute step S3-3;

[0056] Step S3-3, determining whether the outer river water level H in the i-th period is greater than or equal to the inner river water level h;

[0057] Step S3-4, if yes, start the water pump to discharge the water from the inner river to the outer river, and compare the pump discharge flow rate of the water pump with the flow rate value of the drainage channel, and take the smaller one as the discharge flow rate Q;

[0058] If not, the gate is opened to discharge the water from the inner river to the outer river, and the designed discharge capacity of the gate is compared with the flow rate of the channel, and the smaller one is taken as the discharge flow Q;

[0059] Step S3-5, calculating the water volume change ΔV during the time period;

[0060] Step S3-6, calculate the volume V of the inland river i+1 ;

[0061] Step S3-7, listing the inland river water level-inland river volume corresponding to different times, thereby obtaining an inland river water level-inland river volume relationship curve;

[0062] Step S3-8, change the pump discharge flow rate, and repeat the above steps S3-1 to S3-7 to obtain the inland river water level-inland river volume relationship curve under different pump discharge flow rates.

[0063] According to a preferred embodiment of the present invention, in the method for determining the design scale of the drainage pump station, in step S3-5, the following formula is used to calculate the time period change water volume ΔV:

[0064] ΔV=Q*Δt+Qrainfall*Δt Formula (2)

[0065] Among them, ΔV is the change in the volume of the river water body, Q is the outflow of the river, and Q 降雨 is the net rainfall flow into the river, and Δt is the time step.

[0066] According to a preferred embodiment of the present invention, in the method for determining the design scale of the drainage pump station, in step S3-6, the volume of the inland river V is calculated using the following formula: i+1 ;

[0067] V i+1 =V i +ΔV Formula (3)

[0068] Among them, V i Represents the volume of the inland river at time i.

[0069] Example 2

[0070] 1. Determine the drainage area with a drainage area of ​​0.83km 2 The river is 0.55km long. According to the flood control and drainage plan, the drainage standard for this area is 20 years.

[0071] Working conditions: The design flood of 20 years inward meets the flood tide level of 200 years in the outer river.

[0072] 2. To ensure the river is full and clear, and to ensure drainage safety, the landscape low water level is set at 0.8m. The water level of the inner river in the flood-prone area before rainfall is determined, which is the starting water level, that is, the aforementioned landscape low water level of 0.8m;

[0073] 3. Use the drainage channel flow capacity formula to calculate the corresponding channel flow rate under different inland river water levels in the flooded area:

[0074] Table 1 Different inland river water levels corresponding to the river drainage capacity

[0075]

[0076] 5. Select several drainage flow values, and use the corresponding channel flow under different inland river water levels, combined with the discharge of the sluice gate, the discharge of the pump and the net rain flow into the inland river. The relationship curve between the inland river water level and the inland river volume under different pump discharge rates is calculated:

[0077] Table 2 Water level-surge capacity curve

[0078]

[0079]

[0080] 6. According to the relationship curve between inland river water level and inland river volume under different drainage flow values, the highest inland river water level corresponding to each drainage flow value is obtained;

[0081] The following is a preliminary selection of a pump discharge flow rate of 2.5m 3 / s, calculate the regulation and storage plan:

[0082] Table 3 Pump discharge flow rate is 2.5m 3 / s storage calculation process table

[0083]

[0084]

[0085] From Table 3 above, it can be seen that when the pump discharge is 2.5m 3 / s, the highest water level in the river was 2.09m, and the drainage pump was "drained" in the first 2 hours.

[0086] Another pump discharge is planned to be 3.5m 3 / s is taken as the comparison scheme, and the regulation and storage scheme calculation is carried out:

[0087] Table 4 Pump discharge flow rate is 3.5m 3 / s storage calculation process table

[0088]

[0089]

[0090]

[0091] It can be seen from Table 4 that when the pump discharge is 3.5m3 / s, the highest water level in the river is 1.92m, and the drainage pump has a "drainage" phenomenon in the first 3 hours.

[0092] The volume of the inland river in Table 3 and Table 4 is V i+1 They are calculated by the following process:

[0093] Step S3-1, determining whether the inland river water level h in the i-th period is greater than or equal to the inland river water level value;

[0094] Step S3-2: If yes, the discharge flow Q=0;

[0095] If not, continue to execute step S3-3;

[0096] Step S3-3, determining whether the outer river water level H in the i-th period is greater than or equal to the inner river water level h;

[0097] Step S3-4, if yes, start the water pump to discharge the water from the inner river to the outer river, and compare the pump discharge flow rate of the water pump with the flow rate value of the drainage channel, and take the smaller one as the discharge flow rate Q;

[0098] If not, the gate is opened to discharge the water from the inner river to the outer river, and the designed discharge capacity of the gate is compared with the flow rate of the channel, and the smaller one is taken as the discharge flow Q;

[0099] Step S3-5, calculating the water volume change ΔV during the time period;

[0100] Step S3-6, calculate the volume V of the inland river i+1 ;

[0101] Step S3-7, listing the inland river water level-inland river volume corresponding to different times, thereby obtaining an inland river water level-inland river volume relationship curve;

[0102] In summary, when the pump discharge is 2.5m 3 / s, the highest water level in the river is 2.09m, and the drainage pump has a "drainage" phenomenon in the first 2 hours; when the pump discharge is 3.5m 3 / s, the highest water level in the river was 1.92m, and the drainage pump was "drained" in the first 3 hours.

[0103] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for determining the drainage flow of a drainage pump station, characterized in that: The following steps are involved: Step 1: Confirm the flow process boundary of the upstream of the waterlogged area during the flood period and the water level process boundary of the downstream of the waterlogged area during the flood period; Step 2: determine the water level of the inner river in the flood-prone area before rainfall, i.e., the starting water level; calculate the corresponding channel flow rate under different inner river water levels in the flood-prone area; Step 3: Select several drainage flow values, and calculate the relationship curve between the inland river water level and the inland river volume under different pumping flow rates according to the inland river water level, the outer river water level, the corresponding channel flow rate under different inland river water levels, and the discharge gate flow, the pumping flow, and the net rain flow into the inland river; Step 4: According to the relationship curve between the inland river water level and the inland river volume under different drainage flow values, the highest inland river water level corresponding to each drainage flow value is obtained; Step 5: Comprehensively consider the highest inland river water level corresponding to each drainage flow value and the cost of achieving the drainage flow value, and select the best solution. The pump discharge flow in this solution is the drainage flow value of this drainage pump station; In the step 3, according to the inland river water level value, the outer river water level value, the channel flow rate corresponding to different inland river water levels, and combined with the discharge gate flow, the pump discharge flow and the net rain flow flowing into the inland river, the inland river water level-inland river volume relationship curve under different pump discharge flow rates is calculated, which specifically includes the following steps: Step S3-1, determining whether the inland river water level h in the i-th period is greater than or equal to the inland river water level value; Step S3-2: If yes, the discharge flow Q=0; If not, continue to execute step S3-3; Step S3-3, determining whether the outer river water level H in the i-th period is greater than or equal to the inner river water level h; Step S3-4, if yes, start the water pump to discharge the water from the inner river to the outer river, and compare the pump discharge flow rate of the water pump with the flow rate value of the drainage channel, and take the smaller one as the discharge flow rate Q; If not, the gate is opened to discharge the water from the inner river to the outer river, and the designed discharge capacity of the gate is compared with the flow rate of the channel, and the smaller one is taken as the discharge flow Q; Step S3-5, calculating the water volume change ΔV during the time period; Step S3-6: Calculate the volume V of the inland river i+1 ; Step S3-7, listing the inland river water level-inland river volume corresponding to different times, thereby obtaining an inland river water level-inland river volume relationship curve; Step S3-8, change the pump discharge flow rate, and repeat the above steps S3-1 to S3-7 to obtain the inland river water level-inland river volume relationship curve under different pump discharge flow rates.

2. The method for determining the drainage flow of a drainage pump station according to claim 1, characterized in that: In step 3, the corresponding channel capacity under different water levels in the flooded area is calculated using the following formula: Among them, L is the length of the drainage channel, B is the width of the drainage channel, j is the bottom slope of the drainage channel, n is the channel roughness, R is the wetted perimeter, v is the kinematic viscosity, and U is the flow velocity of the drainage channel in the flooded area.

3. The method for determining the drainage flow of a drainage pump station according to claim 1, characterized in that: In the step 2, the drainage water level is determined based on the low water level of the river landscape and the safe water level.

4. The method for determining the drainage flow of a drainage pump station according to claim 1, characterized in that: Before step 1, the following operations need to be performed: determine the drainage standards for the flooded area.

5. The method for determining the drainage flow of a drainage pump station according to claim 1, characterized in that: In step S3-5, the water volume change ΔV during the time period is calculated using the following formula: ΔV = Q * Δt + Q 降雨 * Δt Formula (2) Among them, ΔV is the change in the volume of the river water body, Q is the outflow of the river, and Q 降雨 is the net rainfall flow into the river, and Δt is the time step.

6. The method for determining the drainage flow of a drainage pump station according to claim 1, characterized in that: In step S3-6, the volume V of the inland river is calculated using the following formula: i+1 ; V i+1 =V i +ΔV Formula (3) Among them, V i Represents the volume of the inland river at time i.

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