CN104165817B - Radial flow sediment content real-time measurement apparatus and measuring method - Google Patents

Abstract

A real-time measurement device and method for runoff sediment content, belonging to the field of measurement technology, comprising a measuring barrel, a weighing sensor, a water discharge pipe, an electric valve, a liquid level sensor, a controller, and a processor, and the measuring barrel is placed on the weighing sensor Above, the electric valve is installed on the drain pipe at the bottom of the barrel, the liquid level sensor is installed above the measuring barrel, and the processor is connected to the load cell, electric valve and liquid level sensor respectively through the controller. Set the maximum and minimum water levels in the measuring bucket and the opening and closing time of the electric valve; continuously introduce muddy water into the measuring bucket, measure the water level and weight in the bucket in real time, and transmit the obtained value to the processor through the controller ;When the water level rises to the highest water level, the electric valve opens, and the water in the measuring bucket is discharged; when the water level drops to the lowest water level, the electric valve closes; the processor processes the obtained and set parameters to obtain the runoff sediment in the bucket the weight of. The invention can accurately measure the runoff sediment content of different soil properties, and can realize on-line measurement.

Description

Real-time measurement device and method for runoff sediment content

technical field

The invention belongs to the technical field of measurement, and in particular relates to a device for measuring sediment content and a method for measuring the total amount of runoff by using the device.

Background technique

At present, there are two methods used to measure the runoff sediment content. One is the direct measurement method, such as the drying method, also known as the weighing method. Determine the sand content in the mud water, but because the drying method needs to dry the sample to be tested, and the drying temperature is generally 105°, heating takes about 11 hours, high temperature and long-term heating will cause the organic matter in the soil to be carbonized, and The measured sand concentration is relatively small, and the requirements for drying temperature and heating time also make the entire measurement process time-consuming and laborious. In the field, when people use the drying method to measure the sand concentration on the spot, the alcohol burning dry method will cause large errors in the measured sand concentration, and real-time online detection cannot be realized. Another method is the indirect measurement method, such as capacitance method, laser method, γ-ray method, etc., but affected by temperature, sediment particles, etc., the measurement error is relatively large, especially when the sediment concentration is large or small, it is difficult to measure for accurate measurements. In 2011, our research group applied for a utility model patent "Measuring Device for Sediment Content in Mud Water" (Patent No. ZL201120215645.9), but found during actual use that when the sediment content in muddy water is greater than 3%, Its measurement accuracy is greatly reduced, the reason is that a pressure sensor was used to measure the liquid level, and an ultrasonic sensor was used to measure the liquid level, and the difference between the two liquid levels was used to calculate the sediment content in the muddy water. However, when the mud in the muddy water When there is too much sand, the silt covers the measurement surface of the pressure sensor, which greatly reduces the measurement accuracy.

Contents of the invention

The technical problem to be solved by the invention is to provide a real-time measurement device for runoff sediment content.

The invention also provides a measuring method using the device.

The solution to the technical problem solved by the present invention is to use a measuring bucket, a weighing sensor, a water discharge pipe, an electric valve, a liquid level sensor, a controller and a processor to form a real-time measuring device for the content of runoff sediment, and the measuring bucket is placed on the weighing scale through the lower bracket. On the sensor, the water discharge pipe is connected to the bottom of the measuring tank, the electric valve is installed on the water discharge pipe, the upper bracket is fixed on the upper edge of the measuring tank, the liquid level sensor is installed above the measuring tank through the upper bracket, and the filter tube of the liquid level sensor is in the measuring tank. The controller is respectively connected with the load cell, the electric valve and the liquid level sensor, and the processor is connected with the controller. There is a sink above the measuring barrel to collect the muddy water and inject it into the measuring barrel.

There is a circle of flanging on the upper edge of the measuring barrel, which can keep the measuring barrel from deformation after being filled with water.

The present invention completes the measurement of runoff sediment content through the following steps:

1. Set the highest water level in the measuring tank through the controller , the lowest water level , set the electric valve opening time , valve closing time ; Measure the bottom area of the measuring bucket as , the height from the tank to the bottom of the measuring bucket ;

2. The collected muddy water is continuously introduced into the measuring bucket through the water tank, the water level in the bucket is measured in real time through the liquid level sensor, and the weight of the water in the bucket is measured in real time through the load cell, and the obtained value is transmitted to the processor through the controller ;

3. When the water level rises to the highest level , the controller instructs the electric valve to open, and the water in the measuring barrel is discharged through the water discharge pipe. When the water level drops to the minimum water level , the controller instructs the electric valve to close;

4. The processor processes the obtained and set parameters, and obtains the weight of the runoff sediment in the bucket as:

: Determination of the weight of the runoff sediment in the bucket (Kg)

: Effective muddy water measurement weight in the current bucket (Kg)

The area of the bottom of the bucket is , the muddy water level in the bucket measured by the liquid level sensor in real time , the weight of the muddy water is measured by the load cell , the specific gravity of sediment in muddy water is , the specific gravity of clear water is , C is the air content in water, where , , C can be determined by existing technology;

and the total runoff during the measurement process for:

: The height of the maximum water level in the bucket;

: The minimum water level in the bucket is set;

That is, during the actual measurement , , when reaching When the upper and lower limits are set, the electric valve at the bottom of the device will automatically switch;

: The time it takes for the water to flow into the measured bucket is automatically recorded by the computer processor;

: The number of water releases, automatically recorded by the computer processor;

: Valve opening time refers to the time required from the start of the electric valve to its full opening, which is automatically recorded by the computer;

: Valve closing time, which refers to the time required from the start of electric valve closing to complete closing, which is automatically recorded by the computer;

: The water discharge time refers to the time required from the electric valve is fully opened to discharge the water to the electric valve starts to close and the end of the water discharge is automatically recorded by the computer processor.

In actual measurement, when the water level in the bucket reaches the 0 critical point at the bottom of the bucket (as shown at the bottom of the drum shown in the figure), there is already residual muddy water weight in the bucket ( is a fixed value, manually determined, given value), then on the basis of the preliminary determination of the sediment weight, the actual effective sediment weight in the bucket is considered to be:

: Consider removing the weight of the runoff sediment in the bucket measured by the weight of the residual muddy water in the bucket (Kg);

In addition, in the actual measurement, due to the impulsive force of water, it should be subtracted when calculating the effective sediment weight. The impulsive force is , is the current flow, , is the time taken for the amount of water flowing into the current measured bucket; is the flow velocity when the water level drops in the current measured bucket, , is the density of muddy water, , is the acceleration of gravity.

At this time, the actual effective sediment weight in the bucket is:

which is ;

Therefore consider removing and The final measured actual sediment weight is:

;

W is the more accurate actual sediment weight.

This scheme adopts the weighing sensor, so that the sediment content is not limited. The load cell and high-precision liquid level sensor are used to measure the weight and volume of the liquid on the runoff muddy water. Through interpolation calculation, the runoff sediment content of different soil types can be accurately measured, and online measurement can be realized.

The invention can quickly and accurately measure the sediment content in runoff muddy water in the field of soil erosion research, effectively monitor in the field of comprehensive land management and development and utilization and sewage treatment, and provide data support for prediction of geological disasters (such as debris flow). It can quickly and accurately measure the runoff sediment content of different soil types, realize online continuous measurement, and is not affected by conditions such as muddy water temperature.

Description of drawings

Figure 1 is a schematic diagram of the measurement principle;

Fig. 2 is a cross-sectional view of the measuring barrel part of the device of the present invention.

detailed description

Example 1. The device of the present invention is composed of a measuring barrel 1, a load cell 3, a drain pipe 4, an electric valve 5, a liquid level sensor 7, a controller 9 and a processor 10. The measuring barrel 1 is placed on the load cell through the lower bracket 2. 3, the drain pipe 4 is connected to the bottom 1 of the measuring barrel, the electric valve 5 is installed on the drain pipe 4, the upper bracket 6 is fixed on the upper edge of the measuring barrel 1, the liquid level sensor 7 is installed above the measuring barrel 1 through the upper bracket 6, and the liquid The filter tube 8 of the level sensor 7 is in the measuring tank 1 , the controller 9 is respectively connected to the load cell 3 , the electric valve 5 and the liquid level sensor 7 , and the processor 10 is connected to the controller 9 . The top of the measuring barrel 1 is provided with a water tank that collects muddy water and injects it into the measuring barrel. There is a circle of outer flanging 11 along the measuring barrel 1 . Residual muddy water 12 is in the discharge pipe 4 between the bottom of the measuring bucket 1 and the electric valve 5 .

The present invention completes the measurement of runoff sediment content through the following steps:

1. Set the highest water level in the measuring tank through the controller , the lowest water level , set the electric valve opening time , valve closing time ; Measure the bottom area of the measuring bucket as , the height from the tank to the bottom of the measuring bucket ;

2. The collected muddy water is continuously introduced into the measuring bucket through the water tank, the water level in the bucket is measured in real time through the liquid level sensor, and the weight of the water in the bucket is measured in real time through the load cell, and the obtained value is transmitted to the processor through the controller ;

3. When the water level rises to the highest level , the controller instructs the electric valve to open, and the water in the measuring barrel is discharged through the water discharge pipe. When the water level drops to the minimum water level , the controller instructs the electric valve to close;

4. The processor processes the obtained and set parameters, and obtains the weight of the runoff sediment in the bucket as:

: Determination of the weight of the runoff sediment in the bucket (Kg)

: Effective muddy water measurement weight in the current bucket (Kg)

The area of the bottom of the bucket is , the muddy water level in the bucket measured by the liquid level sensor in real time , the weight of the muddy water is measured by the load cell , the specific gravity of sediment in muddy water is , the specific gravity of clear water is , C is the air content in water, where , , C can be determined by existing technology;

and the total runoff during the measurement process for:

: The height of the maximum water level in the bucket;

: The minimum water level in the bucket is set;

That is, during the actual measurement , , when reaching When the upper and lower limits are set, the electric valve at the bottom of the device will automatically switch;

: The time it takes for the water to flow into the measured bucket is automatically recorded by the computer processor;

: The number of water releases, automatically recorded by the computer processor;

: Valve opening time refers to the time required from the start of the electric valve to its full opening, which is automatically recorded by the computer;

: Valve closing time, which refers to the time required from the start of electric valve closing to complete closing, which is automatically recorded by the computer;

: The water discharge time refers to the time required from the electric valve is fully opened to discharge the water to the electric valve starts to close and the end of the water discharge is automatically recorded by the computer processor.

Example two, total runoff in device of the present invention and actual measurement process Same as Example 1, the actual effective sediment weight is:

: The weight (Kg) of the runoff sediment in the bucket is considered to be measured by removing the residual muddy water in the bucket.

Example three, total runoff in the device of the present invention and the actual measurement process Same as Example 1, the actual effective sediment weight is:

.

The following table 1 and table 2 can reflect the accuracy of the measurement of the prior art and the technology of the present invention. Table 1 is the measurement result of the prior art, and table 2 is the measurement result of the technology of the present invention.

Table 1

Table 2

The results show that the error of many points exceeds 10% for the value measured by the original differential pressure method; the maximum error of the measured data (in 2014) by the current method is less than 5%.

Claims (3)

1. A real-time measurement method for runoff sediment content is characterized by comprising the following steps:

(1) setting the maximum water level in the measuring barrel by the controllerLowest water levelSetting the opening time of the electric valveTime of closing valve(ii) a The area of the bottom of the measuring barrel is measured asHeight from water tank to bottom of measuring barrel；

(2) Continuously guiding the collected muddy water into a measuring barrel through a water tank, measuring the height of the water level in the barrel in real time through a liquid level sensor, measuring the weight of the water in the barrel in real time through a weighing sensor, and transmitting the obtained numerical value to a processor through a controller;

(3) when the water level rises to the highest levelWhen the water level is lowered to the lowest level, the controller instructs the electrically operated valve to open, the water in the measuring barrel is discharged through the water discharge pipeWhen the electric valve is closed, the controller instructs the electric valve to close;

(4) the processor processes the obtained and set parameters to obtain the runoff sediment in the barrel by weight:

: determining the weight of runoff sediment in a bucket

: effective muddy water weight measurement in current bucket

Bottom of barrelArea ofThe level of muddy water in the barrel being measured in real time by a level sensorThe weight of the muddy water is measured by a weighing sensorThe specific gravity of the silt in muddy water isThe clear water has a specific gravity ofC is the air content in water, wherein、C can be determined by the prior art;

and total runoff in the actual measurement processComprises the following steps:

: setting the height of the highest water level in the barrel;

: setting the height of the lowest water level in the barrel;

: the time for the water amount to flow into the actual measurement barrel is automatically recorded by the computer processor;

: the water discharging times are automatically recorded by a computer processor;

: the valve opening time refers to the time required from starting the electric valve to completely opening, and the computer automatically records the time;

: the valve closing time refers to the time required from the starting closing of the electric valve to the complete closing, and is automatically recorded by a computer;

: the water discharging time refers to the time required from the time when the electric valve is completely opened to discharge water to the time when the electric valve starts to close to finish water discharging, and the computer processor automatically records the time.

2. The measurement method according to claim 1, characterized in that: removing the weight of the runoff sediment in the bucket after the weight of the residual muddy water in the bucket is measuredComprises the following steps:

wherein,the residual muddy water weight in the barrelAmount of the compound (A).

3. The method of measuring by the measurement system of claim 2, wherein: removingAndthe actual sediment weight W measured after the influence is as follows:

namely:

wherein, W₂Is the impulsive force of the water and is,；

as to the current flow rate of the flow,；

the time for the water amount to flow into the current actually measured barrel;

the flow speed is the flow speed when the water level in the current actual measurement barrel falls;

；

the density of the muddy water is the density of the muddy water,；

is the acceleration of gravity.