CN202041234U - Final channel flowmeter - Google Patents

Abstract

The utility model relates to a final channel flowmeter, which is characterized in that: after the channel (1) discharges water, the float (7) drives the rotating shaft (5) of the rotation angle displacement sensor (4) to rotate through the connecting rod (6), and the rotation The angular displacement sensor (4) converts the mechanical signal of the rotation angle position into an electrical signal, and transmits it to the flow indicator (9) through the lead wire (8) of the rotation angle displacement sensor (4), so that the flow indicator (9) There is a one-to-one relationship between the deflection angle of the dial pointer and the water depth in the channel (1). The flow value corresponding to the calculated or calibrated corresponding water depth is depicted on the dial of the flow indicator (9) in advance, and the specific value of the flow is obtained by reading the dial flow scale pointed by the dial pointer on the flow indicator (9). It has the characteristics of small investment, high reliability and convenient use.

Description

Final channel flowmeter

Technical field:

The utility model relates to an open channel flow measuring device, in particular to a low-cost irrigation final channel flow measuring device. the

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. the

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. the

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. There is an urgent need for end-channel water measuring equipment that is simple, economical, easy to operate, and easy for the masses to grasp and accept. the

Utility model content:

The purpose of the utility model is to provide an economical, practical and highly reliable special water measuring device for the final channel. the

The purpose of this utility model is achieved in that:

A final channel flowmeter, including the vertical water flow direction spanning above the channel, the two ends are respectively fixed on the beam on the flowmeter bracket symmetrically placed on both sides of the channel, the rotation angle displacement sensor is installed in the middle of the flowmeter beam, and the rotation The rotation axis of the angular displacement sensor is parallel to the beam of the flowmeter, the small head of the drop-shaped float is fixed on the connecting rod, the other end of the connecting rod is fixed on the rotating shaft of the rotation angle displacement sensor, and the lead-out line of the rotation angle displacement sensor is connected to the flow indicator , The rotation angle displacement sensor adopts the potentiometer type angle sensor. the

After the channel is released, the float drives the shaft of the rotation angle displacement sensor to rotate through the connecting rod. The rotation angle displacement sensor converts the mechanical signal of the rotation angle position into an electrical signal, and transmits it to the flow indicator through the lead-out line of the rotation angle displacement sensor. There is a one-to-one relationship between the deflection angle of the dial pointer of the flow indicator and the water depth in the channel. The flow value corresponding to the calculated or calibrated corresponding water depth is depicted on the dial of the flow indicator in advance, and the specific value of the flow is obtained by reading the dial flow scale pointed by the dial pointer on the flow indicator. the

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 dial of the flow indicator. the

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

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),

X—wet circumference (m);

C——The open channel talent appreciation coefficient,

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. the

For non-open channel uniform flow, you can choose a typical channel section and obtain the water depth-flow relationship curve from the actual measurement. Based on this, according to the different water depths in the channel, intercept the corresponding flow value on the curve and depict it on the dial of the flow indicator , for similar canal flow measurements. the

The utility model has the following positive effects:

Special water measuring structures such as water measuring weirs and water tanks are omitted, and the investment is greatly reduced; the invented final channel flowmeter has a simple structure, low cost, and can be used in large quantities, which can save huge 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. the

Description of drawings:

Figure 1 is a top view of the final channel flowmeter placed on the channel. the

Figure 2 is a vertical sectional view of the final channel flowmeter placed on the channel. the

Fig. 3 is a circuit diagram of an embodiment of the final channel flowmeter. the

Detailed ways:

A final channel flowmeter, as shown in Figure 1 and Figure 2, includes: the vertical water flow direction spans above the channel 1, and the two ends are respectively fixed on the beam 3 on the flow meter bracket 2 symmetrically placed on both sides of the channel 1 , the rotation angle displacement sensor 4 is installed in the middle of the flowmeter beam 3, the rotating shaft 5 of the rotation angle displacement sensor 4 is parallel to the flowmeter beam 3, the small head of the drop-shaped float 7 is fixed on the connecting rod 6, and the other end of the connecting rod 6 is fixed On the rotating shaft 5 of the rotation angle displacement sensor 4, the lead wire 8 of the rotation angle displacement sensor 4 is connected to the flow indicator 9, and the rotation angle sensor 4 adopts a potentiometer type angular displacement sensor. the

After the channel 1 discharges water, the float 7 drives the rotating shaft 5 of the rotation angle displacement sensor 4 to rotate through the connecting rod 6. , sent to the flow indicator 9, so that the deflection angle of the dial pointer of the flow indicator 9 has a one-to-one relationship 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 dial of the flow indicator 9 in advance, and the specific value of the flow is obtained by reading the dial flow scale pointed by the dial pointer on the flow indicator 9. the

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, calculate the corresponding flow through the channel according to the following formula, and describe it on the dial of the flow indicator table 9. the

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

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),

X—wet circumference (m);

C——The open channel talent appreciation coefficient,

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. the

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 dial of the flow indicator table 9. , for similar canal flow measurements. the

The embodiment circuit is shown in Figure 3, 1 is a battery pack, 2 and 3 are anti-interference filter capacitors, 4 is a three-terminal voltage regulator integrated circuit, 5 is a full-scale adjustment potentiometer, and 6 is a potentiometer-type rotation angle displacement sensor , 7 is an anti-shake filter capacitor, and 8 is a pointer type DC voltmeter. the

Claims (2)

1. final stage canal capacity meter, it is characterized in that: comprise that Transverse to the flow direction is across channel (1) top, two ends are individually fixed in symmetry and are placed in crossbeam (3) on the flowmeter support (2) of channel (1) both sides, anglec of rotation displacement transducer (4) is installed at middle part at flowmeter crossbeam (3), the rotating shaft (5) of anglec of rotation displacement transducer (4) is parallel to flowmeter crossbeam (3), the microcephaly of water droplet shape float (7) is fixed in connecting rod (6), the other end of connecting rod (6) is fixed in the rotating shaft (5) of anglec of rotation displacement transducer (4), and the extension line (8) of anglec of rotation displacement transducer (4) is connected on the flow indicating gauge (9).

2. a kind of final stage canal capacity meter according to claim 1 is characterized in that: described anglec of rotation displacement transducer (4) adopts the potentiometer type angle displacement sensor.

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