A method for controlling the approach flow of a dam-break model

Abstract

The application discloses a kind of methods for controlling inflow of dam-break model of barrier dam, including collecting the hydraulic element monitoring data of barrier dam-break dam, the hydraulic element monitoring data is preprocessed;According to the hydraulic element monitoring data, the multi-factor coupling simulation of reservoir inflow condition automatic real-time control system is carried out, and barrier dam-break model is obtained;According to control demand, the inflow control is carried out to the barrier dam-break model, and the control instruction of pipe valve opening and flat water tower height is obtained;The inflow control includes controlling test water supply pipe and flat water tower.This method can not only improve the accuracy of dam-break model of barrier dam inflow control, but also has good interpretability, which can be directly applied to barrier dam-break model test inflow control system.

Description

TECHNICAL FIELD

[0001] The present application relates to the control field, in particular to a dam body model inflow control method for dam-break of barrier dam. BACKGROUND

[0002] As a sudden natural disaster, dam-break of barrier dam often brings serious flood threat and life and property loss to downstream areas. The occurrence of this disaster often has high unpredictability and destructiveness, therefore, in-depth study on the mechanism and process of dam-break of barrier dam has important significance for improving early warning ability and formulating effective disaster prevention and mitigation measures.

[0003] In the study of dam-break of barrier dam, physical experiment is an important means. By simulating the formation, development and dam-break process of barrier dam, the internal physical mechanism and influencing factors can be revealed, and basic data can be provided for the establishment and verification of theoretical model. However, the existing experimental technology faces many challenges in practical application.

[0004] The traditional flume test or small reservoir capacity test method often has difficulty in accurately simulating the dam-break process of actual barrier lake in the field due to the limited dam-break reservoir capacity upstream of the barrier body. In these experiments, the action head of the reservoir drops too fast, which leads to a large difference between the duration of the typical stage of the dam-break process and the actual situation. This difference not only affects the in-depth understanding of the dam-break mechanism of barrier dam, but also limits the application value of the experimental results in disaster prevention and mitigation practice. Therefore, it is urgent to propose a new dam-break simulation method of barrier dam to improve the simulation accuracy and reliability of dam-break of barrier dam. SUMMARY

[0005] The purpose of the present application is to provide a dam-break dam body model inflow control method for barrier dam.

[0006] In order to achieve the above purpose, the present application is implemented according to the following technical scheme:

[0007] The present application comprises the following steps:

[0008] Further, the dam-break dam body model inflow control method comprises:

[0009] Calculate the water level-reservoir capacity curve:

[0010]

[0011] Wherein, the reservoir capacity is V, the water level is z, the water surface area of the reservoir at the water level z is A(z), and the lower limit of the reservoir water level is Zb;

[0012] The water balance equation is used to describe the change rate of the reservoir capacity, and the expression is:

[0013]

[0014] Where time is t, and the inflow rate at time t is Q. in (t), where the outflow rate at time t is Q. out (t), the rate of change of reservoir capacity is

[0015] Calculate the rate of change of water level:

[0016]

[0017] The water level change rate The differential of the reservoir capacity V at water level z is The differential of the reservoir capacity V is

[0018] Based on the similarity rule, the similarity of water level drop rates is calculated as follows:

[0019]

[0020] Where the geometric scale is L, and the prototype's water level drop rate is similar to that of... The water level change rate of the model

[0021] The process of calculating the breach flow rate is similar:

[0022] (Q out ) p =L 2.5 (Q out ) m (5)

[0023] Where the model's outlet flow is (Q) out ) m The prototype's export flow rate is (Q out ) p The computation time is similar:

[0024] (dt) p =L 0.5 (dt) m (6)

[0025] The differential of time t is dt, and the time similarity of the prototype is (dt). p The time similarity of the models is (dt). m ;

[0026] Based on real-time monitoring of water level, inflow rate and other data, the outflow rate of the model is calculated using the water balance equation, and then the inflow rate required by the experimental model at the next moment is calculated according to the water level change rate formula.

[0027] Based on the required import flow value of the next time, the automatic real-time control system of the reservoir inflow condition is automatically controlled, and the reservoir inflow flow process is controlled by adjusting the pipe valve opening at a small flow, and the automatic lifting gate of the flat water tower is used to control the reservoir inflow flow process at a large flow.

[0028] The beneficial effects of the present application are:

[0029] Compared with the prior art, the present application has the following technical effects:

[0030] The present application can improve the accuracy of the dam body model inflow control of the dam break, thereby improving the precision of the dam body model inflow control of the dam break, optimizing the dam body model inflow control of the dam break, greatly saving resources, improving work efficiency, realizing intelligent control of the dam body model inflow of the dam break, and performing data optimization and simulation test on the dam body model inflow control of the dam break in real time, overcoming the defect that the dam break process is seriously different due to insufficient capacity of the dam break lake in the existing model test, and having important significance for the dam body model inflow control of the dam break. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The present application is a dam body model inflow control method for a dam break, and the step flow chart is as follows:

[0032] Figure 2 The present application is a dam body model inflow control method for a dam break, and the step flow chart is as follows: DETAILED DESCRIPTION

[0033] The present application is a dam body model inflow control method for a dam break, and the step flow chart is as follows:

[0034] The present application is a dam body model inflow control method for a dam break, and the step flow chart is as follows:

[0035] As shown in Figure 1 The present application is a dam body model inflow control method for a dam break, and the step flow chart is as follows:

[0036] The present application is a dam body model inflow control method for a dam break, and the step flow chart is as follows:

[0037] In the actual evaluation, the upstream reservoir is composed of a main reservoir with a length of 20 m and a width of 12 m and an auxiliary reservoir with a length of 10 m and a width of 12 m, with a height of 1.6 m and a maximum reservoir capacity of 576 m 3 , and the downstream pool has a length of 22 m, a width of 14 m, and a depth of 1.8 m, with a maximum reservoir capacity of 550 m 3 , the test water tank has a length of 18 m, a width of 4 m, and a height of 0.8 m. Water is supplied from the downstream pool by a water pump, and the maximum water supply flow rate is 0.05 m 3 / s; the water level lowering rate of the upstream reservoir is automatically controlled by the flat water tower 5;

[0038] According to the water power element monitoring data, the automatic real-time control system of the reservoir inflow condition is coupled and simulated, and a dam-break model is obtained;

[0039] According to the control requirement, the dam-break model is controlled, and the control instructions of the pipeline valve opening and the flat water tower height are obtained; the inflow control includes controlling the test water supply pipeline and the flat water tower;

[0040] In the actual evaluation, the dam building system includes two winch belt conveyors with lengths of 7.5 m and 6 m respectively, one mixer with a length of 1.0 m 3 , and one rolled steel pipe with a weight of 20 kg; before each test, all the dam building materials are mixed uniformly by the mixer, wetted by the atomizing nozzle, and sampled and weighed to ensure that the water content of the dam building materials is consistent; then, the uniformly mixed dam building materials are conveyed into the water tank by the belt conveyor to build the dam according to the designed dam size, 20 cm thick per layer, and the steel pipe is rolled back and forth for 5 times, the excavation is carried out by the pre-embedded customized organic glass groove, and the excavation is reviewed and corrected by the level instrument after completion.

[0041] The test control takes flow rate as the main control condition, before the water level reaches the bottom elevation of the excavation section, a large flow rate is used to shorten the water filling test time; thereafter, the inflow flow rate controls the non-constant flow rate process according to the test requirement until the breach development is basically balanced, and the test is completed.

[0042] In this embodiment, the method for controlling the inflow according to the dam-break dam body model comprises:

[0043] Calculate the water level-storage capacity curve:

[0044]

[0045] Wherein, the reservoir capacity is V, the water level is z, the water surface area of the reservoir at the water level z is A(z), and the lower limit of the reservoir water level is Zb;

[0046] The water balance equation is used to describe the change rate of the reservoir capacity, and the expression is:

[0047]

[0048] Where time is t, and the inflow rate at time t is Q. in (t), where the outflow rate at time t is Q. out (t), the rate of change of reservoir capacity is

[0049] Calculate the rate of change of water level:

[0050]

[0051] The water level change rate The differential of the reservoir capacity V at water level z is The differential of the reservoir capacity V is

[0052] Based on the similarity rule, the similarity of water level drop rates is calculated as follows:

[0053]

[0054] Where the geometric scale is L, and the prototype's water level drop rate is similar to that of... The water level change rate of the model

[0055] The process of calculating the breach flow rate is similar:

[0056] (Q out ) p =L 2.5 (Q out ) m (5)

[0057] Where the model's outlet flow is (Q) out ) m The prototype's export flow rate is (Q out ) p The computation time is similar:

[0058] (dt) p =L 0.5 (dt) m (6)

[0059] The differential of time t is dt, and the time similarity of the prototype is (dt). p The time similarity of the models is (dt). m ;

[0060] Based on real-time monitoring of water level, inflow rate and other data, the outflow rate of the model is calculated using the water balance equation, and then the inflow rate required by the experimental model at the next moment is calculated according to the water level change rate formula.

[0061] Based on the known next time required import flow value, the reservoir inflow condition automatic real-time control system is automatically controlled, and the reservoir inflow flow process is controlled by adjusting the pipeline valve opening degree at small flow, and the automatic lifting gate of the flat water tower is used to control the reservoir inflow flow process at large flow.

[0062] In actual evaluation, the electromagnetic flowmeter 4 can measure the inflow flow, and the acquisition and control terminal 6 passes through the electromagnetic flowmeter.

[0063] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for controlling the inflow of a dam-break model dam, characterized by, The method comprises the following steps: Collecting the hydraulic element monitoring data of the dam-break of the barrier dam, and preprocessing the hydraulic element monitoring data; Carrying out multi-factor coupling simulation on the reservoir inflow condition automatic real-time control system according to the hydraulic element monitoring data, and obtaining a dam-break model; Carrying out inflow control on the dam-break model according to control requirements, and obtaining control instructions of the pipe valve opening degree and the height of the water tower; the inflow control comprises controlling the test water supply pipe and the water tower; and the method comprises the following steps: Calculating the water level-storage capacity curve: (1) Wherein the reservoir capacity is V, the water level is z, the reservoir water surface area at the water level z is , the lower limit of the reservoir water level is ; Using a water balance equation to describe the reservoir storage capacity change rate, and the expression is: (2) where time is t, the inlet flow rate at time t is the outlet flow rate at time t is the reservoir storage rate of change is ; Calculating the water level change rate: (3) wherein the rate of change of water level is , the differential of reservoir capacity V at water level z is , the differential of reservoir capacity V at water level z is , According to the similarity law, calculating the water level drop rate similarity: (4) where L is the geometric scale, the prototype water level drawdown rate is similar to , and the model water level change rate is ; Calculating the breach flow process similarity: (5) where the model exit flow rate is , the prototype exit flow rate is , and the calculation time is similar: (6) where the differential of time t is the time similarity of the prototype is the time similarity of the model is ; On the basis of real-time monitoring of the water level, inflow and other data, using a water balance equation to calculate the model outflow, and then according to the water level change rate formula, calculating the required import flow of the test model at the next time; On the basis of the known import flow value at the next time, using the reservoir inflow condition automatic real-time control system to automatically control, and when the flow is small, adjusting the pipe valve opening degree to control the reservoir inflow flow process, and when the flow is large, using the water tower automatic lifting gate to control the reservoir inflow flow process.

Images