CN102435230A - Triangular Weir Slope Area Runoff Flow Measurement System - Google Patents

Abstract

The invention discloses a runoff flow measuring system for a slope plot of a triangular weir, and relates to the technical field of water and soil conservation. The system comprises a box body, wherein the box body comprises a water inlet connected with the box body, and a triangular water outlet arranged on the side wall of the box body; the system further comprises: the floater water level meter and the data acquisition unit are connected with each other; the floater water level meter is used for measuring the water level in the box body; and the data acquisition unit is used for reading and recording the water level value of the floater water level meter and calculating the liquid flow passing through the system according to the water level value. The system realizes automatic measurement and recording of the water level by arranging the floater water level meter and the data acquisition unit, and the data acquisition unit can quickly calculate the liquid flow flowing through the system according to the measured water level value.

Description

The domatic sub-district of triangular-notch weir runoff rate measuring system

Technical field

The present invention relates to the conservation technology field, the domatic sub-district of particularly a kind of triangular-notch weir runoff rate measuring system.

Background technology

Sub-district runoff rate measurement is the important content of quantitative examination soil erosion in the water and soil conservation test, in scientific research such as soil erosion qualitative assessment, soil and water conservation benefit evaluation and production practices, all has vital role.The sub-district runoff rate is measured for raising monitoring accuracy and monitoring reliability, the labour intensity that alleviates monitoring and reduction monitoring cost etc. automatically has remarkable meaning.

Receive the restriction of the singularity and the complicacy of field condition environment, water collecting basin method and porous shunting are generally adopted in runoff rate observation in domestic and international domatic sub-district.All there are certain problem in actual use in water collecting basin and part flow arrangement.What water collecting basin and porous shunting were realized is total discharge observation, can not obtain rainfall and produce husky process data.In addition, the design of water collecting basin and part flow arrangement can not be considered all rainfall situation, when heavy rain takes place, is easy to generate overflow, causes the data disappearance.

The runoff process is protected the measure actual benefit for research soil erosion mechanism with evaluation water and is had vital role, and automatic observation has also proposed corresponding requirement to runoff with administrative skill in the modern data transmission.To this, relevant scholar both domestic and external does excessive quantity research to the runoff automatic observation device.Wherein, The tipping bucket method is one of extensive principle that adopts of automatic flow meter; Promptly utilize mechanical measurement element (symmetrical tipping bucket chamber) continuously to be divided into the volume part of single equivalent to fluid, repeatedly be full of one by one and the number of times that discharges is measured fluid volume total amount and process according to measuring chamber.This method receives The Effect of Inertia Force and has nonlinearity erron in practical application.In addition, do not consider and estimation for the role and influence of silt carrying flow.People such as domestic expert Zhao Jun have developed a kind of flow automatic observation device to silt carrying flow; Its cardinal principle is the weight through the flow tube of the flexible link of pulling force sensor induction; Hydraulic model through having the mechanical analysis basis is calculated flow, and according to the influence of sediment charge convection cell weight the flow measurement result is proofreaied and correct.This method has certain application in reality, but the measurement range of existing design and model is limited, uses widely to be still waiting further theoretical expansion and experimental verification.

Triangular-notch weir is to use more a kind ofly during traditional weir flow is measured, and it is low to have a design and construction cost, the characteristics that measurement range is bigger.Traditional triangular-notch weir is through measuring the water level of sluice stream, according to predetermined computing formula calculated flow rate.Most of measurements needs artificial the survey to record water level, hand computation flow again.Grow measuring period, influenced by gauger's subjectivity, precision and reliability receive certain limitation, and simultaneously, time-consuming causing of operating process is difficult to measure enough data points to obtain approximately continuous runoff yield process.Utilize triangular-notch weir to measure flow fast, in real time, exactly and can solve the major issue in production practices and scientific research field, and can the important techniques support be provided for the robotization renewal of water and soil conservation monitoring system.

Summary of the invention

The technical matters that (one) will solve

The technical matters that the present invention will solve is: how a kind of domatic sub-district of the triangular-notch weir runoff rate measuring system that can measure and write down water level automatically is provided.

(2) technical scheme

For solving the problems of the technologies described above; The present invention provides the domatic sub-district of a kind of triangular-notch weir runoff rate measuring system; Said system comprisescasing 100, and saidcasing 100 comprises connectedwater inlet 101, and saidcasing 100 also comprises the trianglewater delivering orifice 102 that is arranged on its sidewall;

Said system also comprises: interconnectedfloat gauge 200 anddata acquisition unit 300;

Saidfloat gauge 200 is used to measure the water level in the saidcasing 100;

Saiddata acquisition unit 300 is used to read and write down the water level value of saidfloat gauge 200, and according to the fluid flow of this water level value calculated flow through said system.

Preferably, saidfloat gauge 200 comprisespulley 201,float 202 and vertical 203;

The disk of saidpulley 201 is fixedly connected with saidcasing 100, and the minimum point of said disk is higher than the sidewall upper edge of saidcasing 100;

The two ends of the rope of saidpulley 201 connect saidfloat 202 and vertical 203 respectively.

Preferably, saidfloat gauge 200 also compriseshousing 204; Saidhousing 204 is fixedly connected with saidcasing 100, and the bottom of saidhousing 204 and 100 conductings of said casing; Saidpulley 201,float 202 and vertical 203 all are arranged on the inside of saidhousing 204.

Preferably, saidfloat gauge 200 is connected with saiddata acquisition unit 300 through data line.

Preferably, the triangle drift angle of said trianglewater delivering orifice 102 down, and drift angle is 30 °.

Preferably, the distance from bottom of the saidcasing 100 of the perigee distance of said trianglewater delivering orifice 102 is 1.6cm.

Preferably, saidcasing 100 is the hollow rectangular parallelepiped of upper shed, and its length and width height is of a size of 30 centimetres of 50 cm x, 50 cm x.

(3) beneficial effect

The domatic sub-district of triangular-notch weir according to the invention runoff rate measuring system; Through float gauge and data acquisition unit are set; Realized automatic measurement and record, and data acquisition unit can calculate the fluid flow of the system of flowing through fast according to the survey water level value to water level.

Description of drawings

Fig. 1 is the partial structurtes synoptic diagram of the domatic sub-district of the described triangular-notch weir of embodiment of the invention runoff rate measuring system;

Fig. 2 is the vertical view of the domatic sub-district of the described triangular-notch weir of embodiment of the invention runoff rate measuring system;

Fig. 3 is the result curve figure of regretional analysis.

Embodiment

Below in conjunction with accompanying drawing and embodiment, specific embodiments of the invention describes in further detail.Following examples are used to explain the present invention, but are not used for limiting scope of the present invention.

Fig. 1 is the partial structurtes synoptic diagram of the domatic sub-district of the described triangular-notch weir of embodiment of the invention runoff rate measuring system; Fig. 2 is the vertical view of the domatic sub-district of the described triangular-notch weir of embodiment of the invention runoff rate measuring system.Like Fig. 1, shown in 2, said system comprisescasing 100,float gauge 200 anddata acquisition unit 300.

Saidcasing 100 is the hollow rectangular parallelepiped of open upper end, and its length and width height is of a size of 30 centimetres of 50 cm x, 50 cm x.Thiscasing 100 compriseswater inlet 101 and water delivering orifice 102.Saidwater inlet 101 is fixedly connected with the right side wall of saidcasing 100, and it is communicated with sub-district runoff inlet through outside mozzle or diversion trench, is used for water is introduced said casing 100.Saidwater delivering orifice 102 is arranged on the left side wall of saidcasing 100, saidwater delivering orifice 102 be shaped as drift angle isosceles triangle down, drift angle is 30 °, and the distance from bottom of the saidcasing 100 of the perigee distance of saidwater delivering orifice 102 is 1.6m.

Saidfloat gauge 200 comprisespulley 201,float 202, vertical 203 andhousing 204.

The left side shrouding of saidhousing 204 is connected with the front side wall of saidcasing 100; The back side seal board of saidhousing 204 is connected with the right side wall of saidcasing 100; The right side shrouding of saidhousing 204 is connected with the right side wall upper edge of saidcasing 100, and the upper sealing plate of saidhousing 204 connects said left side shrouding, back side seal board and right side shrouding.The bottom of the left side shrouding of saidhousing 204 is provided with opening, saidcasing 100 of conducting andhousing 204, and the water level of said like thiscasing 100 andhousing 204 maintains an equal level all thetime.Housing 204 has weakened the image ofcasing 100 interior current fluctuations to level measuring simultaneously, has improved measuring accuracy.

The disk of saidpulley 201 is fixedly connected with the right side wall of saidcasing 100 through saidhousing 204; And the minimum point of said disk is higher than the sidewall upper edge of saidcasing 100; To guarantee thatfloat gauge 200 still can accurately be measured the water level in thecasing 100 under the fair situation of the sidewall of water level and saidcasing 100.

The two ends of the rope of saidpulley 201 connect saidfloat 202 and vertical 203 respectively, and when injecting water saidcasing 100 in, saidfloat 202 goes up and down along with fluctuation in stage, with the saidcasing 100 interior water level values of real-time measurement.

Saiddata acquisition unit 300 connects saidpulley 201 through data line, is used to read and writes down said water level value, and calculate the current value of the saidcasing 100 of flowing through according to said water level value.

Recommend according to " weir notch flow measurement standard ", when crest of weir angle (being the drift angle of triangle water delivering orifice) between π/9-5 π/9 (20 °-100 °) time, the formula that was calculated the weir flow amount by the water level of standard triangular-notch weir is:

$Q=C_D\frac{8}{15}\mathrm{tg}\frac{\mathrm{\θ}}{2}\sqrt{2g}{h}_e^{5/2}---\left(1\right)$

Wherein, Q was the weir flow amount, and unit is cubic metre/hour; C_DBe coefficient of flow; h_eBe effective water level, unit is a rice; h_e=h+K_h, K_hFor considering the corrected value of viscous force and surface tension combined influence, unit is a rice, and h is a rice for actual measurement head (being the distance of water surface distancewater delivering orifice 102 minimum points), unit; θ is crest of weir angle π/6 (promptly 30 °),

ExpressionThe tan value; G is an acceleration of gravity, 9.82 meter per seconds²

For the standard triangular-notch weir, " weir notch flow measurement standard " provides chart, can query flows coefficient C_DWith water level compensation coefficient K_hThe said system of the embodiment of the invention does not adopt the unified standard of weir notch design, but specifically designs with automatic scope installation requirement according to the flow measurement condition of sub-district runoff.Therefore, flow coefficient C_DAnd h_eThe power value must confirm through calibration experiment.According to " weir notch flow measurement standard ", when crest of weir angle (being the drift angle of triangle water delivering orifice 102) when being 30 °, water level compensation coefficient K_hValue 2.3 * 10^-6About rice, the water level difference of this and actual observation is bigger, in the discharge model of this system, can ignore.Therefore, it is following to set up the relation formula model of flow Q and water level h:

Q＝bh^a (2)

A wherein, b is a constant coefficient.

In order to demarcate the said system of the embodiment of the invention, promptly confirm the relation of flow Q and water level h, seminar has carried out one group of flume experiment in China Agricultural University's fluid mechanics laboratory design.Experimental trough is equipped with the standard volume mill weir; The tank end of this standard volume mill weir imports current through simple and easy guiding device thewater inlet 101 of the said system of the embodiment of the invention; With the ascending variation of flow, read the water level ofcasing 100 inside through thedata acquisition unit 300 that is connected withfloat gauge 200 during test.Simultaneously, measure actual flow through said standard volume mill weir, as flow reference value.

According to the result of flume experiment, the water level h that flow Q that the standard volume mill weir is observed and systematic observation of the present invention are read brings formula (2) into, carries out regretional analysis, and the value that obtains constant coefficient a is 1.9, and the value of constant coefficient b is 0.002.Therefore calibrated formula (2) is as follows:

Q＝0.002h^1.9 (2)

Fig. 3 is the result curve figure of regretional analysis; As shown in Figure 3; The up-and-down boundary (two dotted lines among Fig. 3) of 95% fiducial interval can be found out from figure: the water level of system of the present invention (promptly surveying head) presents extraordinary correlationship with flow, and relevant definite coefficient is 0.98.It can also be seen that from Fig. 3: most of observation station is in 95% fiducial interval, and particularly when flow during less than 5 cubic metres/hour, the scope of fiducial interval is very little; When flow during greater than 5 cubic metres/hour, the uncertainty of model increases with flow.This is because in the discharge model derivation, supposes that the water level compensation coefficient is 0, has promptly ignored velocity of approach.Therefore, at flow hour, flow rate of water flow is less, and the error that model hypothesis causes is less; After flow velocity is along with flow increase and increase, ignore the water level error increase that velocity of approach causes.But in general, the flow simplified model all just has stable predicting the outcome at 10 cubic metres/hour with interior.What extensively adopt in the world at present all is 20 meters * 5 meters standard sub-district runoff, under 100 millimeters/hour raininess condition, does not consider that vegetation is held back and soil infiltration, and the peak runoff that can produce is that 2400 milliliters/second are 8.64 cubic metres/hour.Therefore, the said system of this inventive embodiments fully can be used for calculated flow rate when runoff plots is used in the open air, and its precision can satisfy engineering request.

Also there is reliable and stable observed result in the said system of this inventive embodiments to the flow above 8.64 cubic metres/hour.The flow that we plan to measure expands 15 cubic metres/hour to, is equivalent to the runoff yield of 200 millimeters/hour clean rainfalls in standard sub-district.To bigger non-standard runoff plots or the bigger area of storm intensity, can adopt this recording geometry equally, just when the sub-district area was bigger, the size of system was bigger possibly.Need other calibrational capacity model simultaneously or the said discharge model of formula (2) is done certain correction.

The domatic sub-district of the said triangular-notch weir of embodiment of the invention runoff rate measuring system; Through float gauge and data acquisition unit are set; Automatic measurement and record have been realized to water level; And data acquisition unit can calculate the fluid flow of the system of flowing through fast according to the survey water level value, thereby upgrade for the robotization of water and soil conservation monitoring system the important techniques support is provided.

Above embodiment only is used to explain the present invention; And be not limitation of the present invention; The those of ordinary skill in relevant technologies field under the situation that does not break away from the spirit and scope of the present invention, can also be made various variations and modification; Therefore all technical schemes that are equal to also belong to category of the present invention, and scope of patent protection of the present invention should be defined by the claims.

Claims (7)

Translated fromChinese

1.一种三角堰坡面小区径流流量测量系统，所述系统包括箱体(100)，所述箱体(100)包括与其连接的进水(101)，所述箱体(100)还包括设置在其侧壁上的三角形出水口(102)；1. a triangular weir slope surface small area runoff flow measurement system, said system comprises casing (100), and said casing (100) comprises the inlet water (101) that is connected with it, and described casing (100) also comprises A triangular water outlet (102) arranged on its side wall;其特征在于，所述系统还包括：互相连接的浮子水位计(200)和数据采集器(300)；It is characterized in that the system also includes: a float water level gauge (200) and a data collector (300) connected to each other;所述浮子水位计(200)用于测量所述箱体(100)内的水位；The float water level gauge (200) is used to measure the water level in the tank (100);所述数据采集器(300)用于读取和记录所述浮子水位计(200)的水位值，并根据该水位值计算流经所述系统的液体流量。The data collector (300) is used to read and record the water level value of the float water level gauge (200), and calculate the liquid flow through the system according to the water level value.2.如权利要求1所述的系统，其特征在于，所述浮子水位计(200)包括滑轮(201)、浮子(202)和铅垂(203)；2. The system according to claim 1, characterized in that, the float water level gauge (200) comprises a pulley (201), a float (202) and a plumb (203);所述滑轮(201)的圆盘与所述箱体(100)固定连接，并且所述圆盘的最低点高于所述箱体(100)的侧壁上沿；The disk of the pulley (201) is fixedly connected to the box (100), and the lowest point of the disk is higher than the upper edge of the side wall of the box (100);所述滑轮(201)的绳索的两端分别连接所述浮子(202)和铅垂(203)。The two ends of the rope of the pulley (201) are respectively connected with the buoy (202) and the plumb (203).3.如权利要求2所述的系统，其特征在于，所述浮子水位计(200)还包括壳体(204)；所述壳体(204)与所述箱体(100)固定连接，并且所述壳体(204)的下部与所述箱体(100)导通；所述滑轮(201)、浮子(202)和铅垂(203)均设置在所述壳体(204)的内部。3. The system according to claim 2, characterized in that, the float water level gauge (200) also includes a housing (204); the housing (204) is fixedly connected to the casing (100), and The lower part of the housing (204) is in communication with the box (100); the pulley (201), the float (202) and the plumb (203) are all arranged inside the housing (204).4.如权利要求1所述的系统，其特征在于，所述浮子水位计(200)通过数据线与所述数据采集器(300)连接。4. The system according to claim 1, characterized in that, the float water level gauge (200) is connected with the data collector (300) through a data line.5.如权利要求1所述的系统，其特征在于，所述三角形出水口(102)的三角形顶角朝下，并且顶角为30°。5. The system according to claim 1, characterized in that, the triangular apex of the triangular water outlet (102) faces downward, and the apex angle is 30°.6.如权利要求1所述的系统，其特征在于，所述所述三角形出水(102)的最低点距离所述箱体(100)的底部距离为1.6cm。6. The system according to claim 1, characterized in that the distance from the lowest point of the triangular outlet (102) to the bottom of the box (100) is 1.6 cm.7.如权利要求1所述的系统，其特征在于，所述箱体(100)为上开口的中空长方体，其长宽高尺寸为50厘米×50厘米×30厘米。7. The system according to claim 1, characterized in that, the box (100) is a hollow cuboid with an upper opening, and its length, width and height are 50 cm x 50 cm x 30 cm.

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