CN102221382A - Irrigation ditch simple and easy flowmeter - Google Patents

Abstract

The invention relates to a special water measuring device for irrigating agricultural canals, which is characterized in that: after the channel (1) discharges water, the float (4) is driven by the outer casing of the connecting rod (5) and the bearing (6) installed in the middle of the cross bar (3) The pointer (7) fixed on the outer cover of the bearing (6) deflects, and the deflection angle of the pointer (7) has a one-to-one correspondence with the depth of water in the channel (1). The flow value corresponding to the calculated or calibrated corresponding water depth is depicted on the flow indicator dial (8) in advance, and the specific value of the flow rate is obtained by reading the flow scale on the flow indicator dial (8) pointed by the pointer (7). It has the characteristics of small investment, high reliability and convenient use.

Description

Farm canal simple flow meter

Technical field:

The invention relates to an open channel flow measuring device, in particular to a low-cost irrigation canal flow measuring device.

Background technique:

Water measurement in irrigation areas is a necessary measure for rationally dispatching irrigation water sources, correctly implementing water use plans, and strengthening water management.

To measure water in irrigation canal systems, water-measuring structures such as water-measuring weirs and water-measuring tanks are usually specially set up on the canal systems. Through the scientific shrinkage of the water-passing section of the main section of the water-measuring buildings, a certain water level difference is formed between the upstream and downstream, so that A relatively stable relationship between water level and flow is obtained. Water level monitoring is the basic work of flow calculation using specially designed water measuring structures. At present, the water level sensors used in irrigation areas mainly include float sensors, pressure sensors and ultrasonic sensors.

Although the open channel flow measurement technology and equipment are quite mature, due to the wide area and large volume of the final channel (bucket canal, agricultural canal), the existing open channel flow measurement device is applied to the final channel, because there are problems in investment, operation, maintenance, etc. , which restricts the application and promotion of water measurement in the final channel. Therefore, the flow measurement of the end channel has always been a weak link in the measurement of agricultural irrigation water. In particular, agricultural canals have the largest number of end-level canals and involve thousands of households in irrigation areas. There is an urgent need for agricultural canal water measuring equipment that is simple, economical, easy to operate, and easy for the masses to grasp and accept.

Invention content:

The object of the present invention is to provide an economical, practical and highly reliable simple water measuring device dedicated to agricultural canals.

The purpose of the present invention is achieved like this:

A simple water meter dedicated to agricultural canals, comprising a cross bar that spans the top of the canal in the vertical direction of water flow, two ends of which are respectively fixed on the flow meter brackets symmetrically placed on both sides of the canal, and an inner sleeve fixed to a bearing in the middle of the cross bar. The float is in the shape of a water drop. The small head of the float is fixed on one end of the connecting rod, and the other end of the connecting rod is fixed on the outer casing of the bearing installed in the middle of the cross bar. The pointer fixed on the outer casing of the bearing is fixed on the flow indicator on the cross bar. Dial, flow indication The plane where the dial is located is perpendicular to the bar and close to the pointer.

After the channel is drained, the float drives the pointer fixed on the bearing jacket to deflect through the connecting rod and the bearing jacket installed in the middle of the cross bar. The deflection angle of the pointer has a one-to-one correspondence with the water depth in the channel. The flow value corresponding to the calculated or calibrated corresponding water depth is depicted on the flow indicator dial in advance, and the specific value of the flow rate is obtained by reading the flow scale on the flow indicator dial pointed by the pointer.

The acquisition of the flow scale is divided into two situations. When the length is greater than 20 times the maximum water depth, an open channel uniform flow is formed in the channel, and the flow is calculated using the open channel uniform flow formula. According to the different water depths in the channel, the corresponding flow through the channel is calculated according to the following formula, and it is depicted on the flow indicator dial.

$\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; AC</span>}\sqrt{\mathrm{<span\; class="notranslate">\; Ri</span>}}$

In the formula, Q——flow rate (m ³ /s);

A——The cross-sectional area of water (m ² );

i—hydraulic slope, which is the same as the longitudinal slope of the canal bottom;

R——hydraulic radius of water-passing section (m), $R=\frac{A}{x};$

X—wet circumference (m);

C——The open channel talent appreciation coefficient, $C=\frac{1}{\mathrm{no}}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HSA00000447386000011.png,HSA00000447386000012.png"\; state="\{\{state\}\}">R</figure-callout>}}^{1/6}$

n——roughness coefficient, which can be measured actually, and the following values can also be referred to: for smooth boards, n=0.012; for concrete, n=0.014; for stone masonry, n=0.015.

For the uniform flow in non-open channels, typical channel sections can be selected, and the water depth-flow relationship curve can be obtained by actual measurement. Based on this, according to different water depths in the channel, the corresponding flow value on the curve can be intercepted and depicted on the flow indicator dial for use Similar canal flow measurements.

The present invention has following positive effect:

Special water measuring structures such as water measuring weirs and water tanks are omitted, and the investment is greatly reduced; the simple structure of the simple agricultural canal flowmeter invented is simple, low in cost, and can be used in large quantities, which can save a huge amount of investment; simple structure, easy to disassemble and move It is very convenient and can be used in a mobile cycle, which reduces the chance of being stolen; no training is required, only a simple explanation is required, and it can be used proficiently; the structure is simple, the probability of failure is small, and the reliability is high.

Description of drawings:

Figure 1 is a vertical section view of a simple flowmeter for an agricultural canal placed on the canal.

Figure 2 is a top view of a simple flowmeter for an agricultural canal placed on the canal.

Detailed ways:

A simple water meter dedicated to agricultural canals, as shown in Figures 1 and 2, comprising: the vertical water flow direction spans above the channel 1, and the two ends are respectively fixed on the flow meter brackets 2 symmetrically placed on both sides of the channel 1 The crossbar 3, the inner sleeve is fixed on the bearing 6 in the middle of the crossbar 3, the float 4 is in the shape of a water drop, the small head of the float 4 is fixed on one end of the connecting rod 5, and the other end of the connecting rod is fixed on the bearing 6 installed in the middle of the crossbar 3 On the jacket, the pointer 7 fixed on the bearing 6 jacket, the flow indicating dial 8 fixed on the cross bar 3, the plane where the flow indicating dial 8 is located is perpendicular to the cross bar 3 and close to the pointer 7.

After the channel 1 discharges water, the float 4 drives the pointer 7 fixed on the outer cover of the bearing 6 to deflect through the connecting rod 5 and the outer casing of the bearing 6 installed in the middle of the cross bar 3. The deflection angle of the pointer 7 corresponds to the water depth in the channel 1. definite relationship. The flow value corresponding to the calculated or calibrated corresponding water depth is depicted on the flow indicating dial 8 in advance, and the specific value of the flow is obtained by reading the flow scale on the flow indicating dial 8 pointed by the pointer 7 .

Embodiment: When the length is greater than 20 times the maximum water depth, an open channel uniform flow is formed in the channel, and the flow is calculated with the open channel uniform flow formula. According to different water depths in the channel, the corresponding flow through the channel is calculated according to the following formula, and depicted on the flow indicating dial 8.

$\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; AC</span>}\sqrt{\mathrm{<span\; class="notranslate">\; Ri</span>}}$

In the formula, Q——flow rate (m ³ /s);

A——the cross-sectional area of water (m ² );

i—hydraulic slope, which is the same as the longitudinal slope of the canal bottom;

R——hydraulic radius of water-passing section (m), $R=\frac{A}{x};$

X—wet circumference (m);

C——The open channel talent appreciation coefficient, $C=\frac{1}{\mathrm{no}}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HSA00000447386000011.png,HSA00000447386000012.png"\; state="\{\{state\}\}">R</figure-callout>}}^{1/6}$

n——roughness coefficient, which can be measured actually, and the following values can also be referred to: for smooth boards, n=0.012; for concrete, n=0.014; for stone masonry, n=0.015.

For the uniform flow in non-open channels, typical canal sections can be selected, and the water depth-flow relationship curve can be obtained by actual measurement. Based on this, according to different water depths in the channel, the corresponding flow value on the curve can be intercepted and depicted on the flow indicator dial 8. Similar to channel flow measurements.

Claims (2)

1. A special water measuring device for irrigation canals, comprising a horizontal bar that spans above the canal (1) in the vertical direction of water flow, and the two ends are respectively fixed on the flow meter brackets (2) symmetrically placed on both sides of the canal (1) (3), the inner sleeve is fixed on the bearing (6) in the middle of the cross bar (3), the float (4) is in the shape of a water drop, the small head of the float (4) is fixed on one end of the connecting rod (5), and the other end of the connecting rod is fixed On the overcoat of the bearing (6) installed in the middle part of the cross bar (3), the pointer 7 fixed on the overcoat of the bearing (6) is fixed on the flow indicating dial (8) on the cross bar (3), and the flow indicating dial ( 8) The plane where it is located is perpendicular to the crossbar (3) and close to the pointer (7). 2. A special water measuring device for irrigation canals according to claim 1, characterized in that: after the canal (1) discharges water, the float (4) passes through the connecting rod (5) and the middle part of the cross bar (3). Bearing (6) casing drives pointer (7) fixed on bearing (6) casing to deflect. The deflection angle of pointer (7) has a one-to-one correspondence with the depth of water in channel (1). Calculate or calibrate in advance The flow value corresponding to the corresponding water depth is depicted on the flow indicating dial (8), and the flow specific value is obtained by reading the flow scale on the flow indicating dial (8) pointed by the pointer (7).

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