Flow metering device and method for low-flow precipitation well

Abstract

A flow metering device for a low-flow precipitation well and a metering method thereof, relating to the technical field of infrastructure construction, the device comprises a solenoid valve group, a counter, and two volume boxes; the solenoid valve group has three water inlets and three water outlets, and the solenoid valve group has two working positions; one water inlet of the solenoid valve group is connected to the external drainage pipe of the precipitation well, and the other two water inlets are respectively connected to the drainage outlets of the two volume boxes; one water outlet of the solenoid valve group is connected to the external drainage discharge point of the precipitation well, and the other two water outlets are respectively connected to the water inlets of the two volume boxes; both volume boxes are provided with liquid level sensors, and the solenoid valve group is controlled to switch the working position and trigger the counter to count by the liquid level sensor. The device provided by the present invention is particularly suitable for flow metering of precipitation wells with low flow or interruption.

Description

Technical Field

[0001] The invention relates to infrastructure construction technology, in particular to a low-flow precipitation well flow metering device and a metering method thereof. Background Art

[0002] In the control of foundation pit groundwater, accurate measurement and statistics of the external drainage volume of the dewatering well is a basic task, which can be used for risk analysis and risk prediction for real-time and effective foundation pit groundwater control. However, the data statistics of the current engineering site are relatively chaotic, especially in the process of foundation pit dewatering in soft soil areas. If the dewatering target layer is a clay layer or a silty clay layer, or the dewatering target layer is completely blocked by a water-stop curtain, the following abnormal situations often occur in these scenarios: 1) The water output of the dewatering well is small, and there is often an obvious interruption phenomenon. The external drainage contains a large amount of gas, which significantly interferes with the measurement of conventional mechanical water meters, electromagnetic flow meters, ultrasonic flow meters and other measuring instruments; 2) Due to the low external drainage volume, a vacuum is often added to the well to enhance the pumping effect, causing the conventional metering water meter to reverse and the metering data to be obviously unreasonable; 3) During the shallow drainage process, the groundwater quality is poor and contains more impurities, which causes the conventional metering water meter to stop in a short period of time and the metering meter is unclear.

[0003] When the above abnormal situation occurs, it will cause large errors in the measurement data of the drainage volume outside the precipitation well. Summary of the invention

[0004] In view of the defects existing in the above-mentioned prior art, the technical problem to be solved by the present invention is to provide a low-flow precipitation well flow metering device and a metering method thereof which can accurately measure the amount of water discharged outside the precipitation well in low-flow or interrupted flow conditions.

[0005] In order to solve the above technical problems, the present invention provides a flow metering device for a low-flow precipitation well, which is characterized by comprising a solenoid valve group, a counter, and two volume boxes;

[0006] The solenoid valve group has three water inlets and three water outlets, and the solenoid valve group has two working positions; the three water inlets of the solenoid valve group are respectively the first water inlet, the second water inlet, and the third water inlet, and the three water outlets of the solenoid valve group are respectively the first water outlet, the second water outlet, and the third water outlet;

[0007] When the solenoid valve group is switched to the first working position, the water inlet and the water outlet of the solenoid valve group are connected in the following manner: the first water inlet is isolated from each water outlet, the second water inlet is only connected to the second water outlet, and the third water inlet is only connected to the first water outlet;

[0008] When the solenoid valve group is switched to the second working position, the water inlet and the water outlet of the solenoid valve group are connected in the following manner: the first water inlet is only connected to the first water outlet, the second water inlet is only connected to the third water outlet, and the third water inlet is isolated from each water outlet;

[0009] The volume box is provided with a flow scale for indicating the water volume in the box, the upper end of the volume box is provided with a water inlet, and the lower end of the volume box is provided with a drain, one of the volume boxes is a first volume box, and the other volume box is a second volume box;

[0010] The first water inlet of the solenoid valve group is connected to the drain port of the first volume tank, the second water inlet of the solenoid valve group is connected to the external drainage pipe of the precipitation well, and the third water inlet of the solenoid valve group is connected to the drain port of the second volume tank;

[0011] The first water outlet of the solenoid valve group is connected to the drainage point outside the precipitation well through a pipe, the second water outlet of the solenoid valve group is connected to the water inlet of the first volume tank, and the third water outlet of the solenoid valve group is connected to the water inlet of the second volume tank;

[0012] The first volume box and the second volume box are both provided with liquid level sensors, and the signal output ports of the liquid level sensors in the two volume boxes are respectively connected to the control ports of the solenoid valve group, so as to control the solenoid valve group to switch the working position, and the signal output port of the liquid level sensor in the second volume box is connected to the counting signal input port of the counter, so as to trigger the counter to count;

[0013] When the liquid level sensor in the first volume tank detects that the water level in the tank reaches the position of the liquid level sensor, the liquid level sensor can output a corresponding signal to the control port of the solenoid valve group, thereby triggering the solenoid valve group to switch to the second working position;

[0014] When the liquid level sensor in the second volume tank detects that the water level in the tank reaches the position of the liquid level sensor, the liquid level sensor can output a corresponding signal to the control port of the solenoid valve group and the counting signal input port of the counter, thereby triggering the solenoid valve group to switch to the first working position and triggering the counter, so that the count value of the counter increases by 1.

[0015] Furthermore, it also includes a remote monitoring terminal, a flow acquisition module, and water level gauges are provided in both volume boxes;

[0016] The flow acquisition module is used to collect water level data from two water level meters and send it to a remote monitoring terminal. The two data acquisition ports of the flow acquisition module are respectively connected to the water level data output ports of the two water level meters, and the flow acquisition module is connected to the remote monitoring terminal via a communication network.

[0017] The metering method of the flow metering device of the low-flow precipitation well provided by the present invention is characterized in that the total flow calculation formula of the drainage outside the precipitation well is:

[0018] Q t =Q t-dt +S×(max(H1 t -H1 t-dt ,0)+max(H2 t -H2 t-dt ,0))

[0019] In the formula, Q t is the total drainage flow of the precipitation well at time t, Q t-dt is the total drainage flow of the precipitation well at time t-dt, dt is the preset water level data collection interval, S is the bottom area of ​​the volume box, H1 t is the water level of the first volume tank at time t, H1 t-dt is the water level of the first volume tank at time t-dt, H2 t is the water level of the second volume tank at time t, H2 t-dt is the water level of the second volume tank at time t-dt, and max() is the maximum value function.

[0020] Furthermore, based on the calculation result of the total flow rate of the drainage outside the precipitation well, the average flow rate of the drainage outside the precipitation well is further calculated, and the calculation formula is:

[0021]

[0022] In the formula, is the average flow rate of drainage outside the precipitation well, Q t1 is the total flow rate of drainage outside the precipitation well at time t1, Q t2 is the total flow of drainage outside the precipitation well at time t2, and t1 and t2 are two total flow measurement time points.

[0023] The low-flow precipitation well flow metering device and the metering method provided by the present invention utilize flow direction control to realize the water inlet conversion and constant-flow drainage of two volume boxes, and through the cooperation of a counter and a flow ruler, accurate measurement of the drainage volume outside the precipitation well can be achieved under low-flow or interrupted-flow conditions. At the same time, the interference of gas and impurities on the data and the damage to the instrument can also be solved. After adding a remote monitoring terminal, a flow acquisition module and a water level meter, remote monitoring of the drainage flow outside the precipitation well can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 2 is a schematic structural diagram of a flow metering device for a low-flow precipitation well according to a first embodiment of the present invention;

[0025] Figure 2It is a structural schematic diagram of a low-flow precipitation well flow metering device according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0026] The following is a further detailed description of an embodiment of the present invention in conjunction with the accompanying drawings, but this embodiment is not intended to limit the present invention. All similar structures and similar variations of the present invention should be included in the protection scope of the present invention. The commas in the present invention represent the relationship of and, and the English letters in the present invention are case-sensitive.

[0027] like Figure 1 As shown, a flow metering device for a low-flow precipitation well provided by the first embodiment of the present invention is characterized by comprising a solenoid valve group H1, a counter J1, and two volume boxes U1, U2;

[0028] The solenoid valve group H1 has three water inlets and three water outlets, and the solenoid valve group H1 has two working positions; the three water inlets of the solenoid valve group are respectively the first water inlet A1, the second water inlet A2, and the third water inlet A3, and the three water outlets of the solenoid valve group are respectively the first water outlet B1, the second water outlet B2, and the third water outlet B3;

[0029] When the solenoid valve group H1 is switched to the first working position, the water inlet and the water outlet of the solenoid valve group are connected in the following manner: the first water inlet A1 is isolated from each water outlet, the second water inlet A2 is only connected to the second water outlet B2, and the third water inlet A3 is only connected to the first water outlet B1;

[0030] When the solenoid valve group H1 is switched to the second working position, the water inlet and the water outlet of the solenoid valve group are connected in the following manner: the first water inlet A1 is only connected to the first water outlet B1, the second water inlet A2 is only connected to the third water outlet B3, and the third water inlet A3 is isolated from each water outlet;

[0031] The volume box is provided with a flow scale L1 for indicating the water volume in the box, a water inlet is provided at the upper end of the volume box, and a drain is provided at the lower end of the volume box. One of the volume boxes is the first volume box U1, and the other volume box is the second volume box U2;

[0032] The first water inlet A1 of the solenoid valve group is connected to the drain port of the first volume tank U1, the second water inlet A2 of the solenoid valve group is connected to the external drainage pipe of the precipitation well, and the third water inlet A3 of the solenoid valve group is connected to the drain port of the second volume tank U2;

[0033] The first water outlet B1 of the solenoid valve group is connected to the drainage point outside the precipitation well through a pipe, the second water outlet B2 of the solenoid valve group is connected to the water inlet of the first volume tank U1, and the third water outlet B3 of the solenoid valve group is connected to the water inlet of the second volume tank U2;

[0034] A liquid level sensor P1 is provided in the first volume tank U1, and a liquid level sensor P2 is provided in the second volume tank U2. The signal output ports of the liquid level sensors P1 and P2 in the two volume tanks are respectively connected to the control port of the solenoid valve group H1, so as to control the solenoid valve group H1 to switch the working position, and the signal output port of the liquid level sensor P2 in the second volume tank is connected to the counting signal input port of the counter J1, so as to trigger the counter J1 to count;

[0035] When the liquid level sensor P1 in the first volume tank detects that the water level in the tank reaches the position of the liquid level sensor, the liquid level sensor can output a corresponding signal to the control port of the solenoid valve group H1, thereby triggering the solenoid valve group H1 to switch to the second working position;

[0036] When the liquid level sensor P2 in the second volume tank detects that the water level in the tank reaches the position of the liquid level sensor, the liquid level sensor can output a corresponding signal to the control port of the solenoid valve group H1 and the counting signal input port of the counter J1, thereby triggering the solenoid valve group H1 to switch to the first working position and triggering the counter J1, so that the count value of the counter J1 increases by 1.

[0037] In the first embodiment of the present invention, the solenoid valve group is composed of a one-inlet and two-outlet solenoid reversing valve and a two-inlet and one-outlet solenoid reversing valve. In other embodiments of the present invention, the solenoid valve group may also adopt a combination of other solenoid valves.

[0038] The metering method of the first embodiment of the present invention is as follows:

[0039] In the initial state, the solenoid valve group H1 is in the first working position, and the first volume tank U1 and the second volume tank U2 are both empty. At this time, the external drainage of the precipitation well passes through the external drainage pipe, flows through the second water inlet A2 and the second water outlet B2 of the solenoid valve group in sequence, and then enters the first volume tank U1;

[0040] When the water level in the first volume tank U1 reaches the position of the liquid level sensor P1, the liquid level sensor P1 outputs a corresponding signal to trigger the solenoid valve group H1 to switch to the second working position;

[0041] After the solenoid valve group H1 is switched to the second working position, the water in the first volume tank U1 begins to be discharged, and after flowing through the first water inlet A1 and the first water outlet B1 of the solenoid valve group in sequence, it is discharged to the drainage point outside the precipitation well through the pipe fittings;

[0042] After the solenoid valve group H1 is switched to the second working position, the external drainage of the precipitation well flows through the external drainage pipe, and then flows through the second water inlet A2 and the third water outlet B3 of the solenoid valve group and enters the second volume tank U2;

[0043] When the water level in the second volume tank U2 reaches the position of the liquid level sensor P2, the water in the first volume tank U1 has also been emptied. At this time, the liquid level sensor P2 outputs a corresponding signal to trigger the solenoid valve group H1 to switch to the first working position, and triggers the counter J1, so that the count value of the counter J1 increases by 1;

[0044] Every time the count value of counter J1 increases by 1, it represents the end of the current metering cycle and the beginning of the next metering cycle. The drainage flow rate of the precipitation well in a single metering cycle is the sum of the capacities of the two volume tanks. The capacity of the volume tank refers to the volume of water in the tank when the water reaches the position of the liquid level sensor.

[0045] The total external drainage flow of the precipitation well during the entire measurement period is: Q = N × V + Vt;

[0046] In the formula, Q is the total drainage flow of the precipitation well, N is the count value of the counter, and V is the sum of the capacities of the two volume boxes;

[0047] If the solenoid valve group H1 is in the first working position, Vt is the water capacity in the first volume tank indicated by the flow scale. If the solenoid valve group H1 is in the second working position, Vt is the water capacity in the second volume tank indicated by the flow scale.

[0048] like Figure 2 As shown, the difference between the second embodiment of the present invention and the first embodiment is that: in the second embodiment, a remote monitoring terminal M1 and a flow acquisition module M2 are further included, a water level meter P3 is provided in the first volume tank U1, and a water level meter P4 is provided in the second volume tank U2;

[0049] The flow acquisition module M2 is used to collect water level data of the two water level meters P3 and P4 and send it to the remote monitoring terminal M1. The two data acquisition ports of the flow acquisition module M2 are respectively connected to the water level data output ports of the two water level meters P3 and P4, and the flow acquisition module M2 is connected to the remote monitoring terminal M1 through a communication network.

[0050] In the second embodiment of the present invention, the water level meter, remote monitoring terminal and flow collection module are all prior art. The remote monitoring terminal adopts a computer, and the flow collection module can adopt a data collection board with communication function.

[0051] Compared with the first embodiment, the second embodiment of the present invention can realize remote monitoring of the drainage flow outside the precipitation well. Since the flow mark ruler cannot be viewed during remote monitoring, the total flow of the drainage outside the precipitation well can be obtained by calculation. The calculation formula is:

[0052] Q t =Q t-dt +S×(max(H1 t -H1t-dt ,0)+max(H2 t -H2 t-dt ,0))

[0053] In the formula, Q t is the total drainage flow of the precipitation well at time t, Q t-dt is the total drainage flow of the precipitation well at time t-dt, dt is the preset water level data collection interval, S is the bottom area of ​​the volume box, H1 t is the water level of the first volume tank at time t, H1 t-dt is the water level of the first volume tank at time t-dt, H2 t is the water level of the second volume tank at time t, H2 t-dt is the water level of the second volume tank at time t-dt, and max() is the maximum value function.

[0054] According to the calculation results of the total flow of drainage outside the precipitation well, the average flow of drainage outside the precipitation well can be further calculated. The calculation formula is:

[0055]

[0056] In the formula, is the average flow rate of drainage outside the precipitation well, Q t1 is the total flow rate of drainage outside the precipitation well at time t1, Q t2 is the total flow of drainage outside the precipitation well at time t2, t1 and t2 are two total flow measurement time points, and t1-t2 is the time difference between the two measurement time points t1 and t2.

Claims

1. A flow metering device for low-flow precipitation wells, Features: It includes a solenoid valve group, a counter, and two volume boxes; The solenoid valve group has three water inlets and three water outlets, and the solenoid valve group has two working positions; the three water inlets of the solenoid valve group are respectively the first water inlet, the second water inlet, and the third water inlet, and the three water outlets of the solenoid valve group are respectively the first water outlet, the second water outlet, and the third water outlet; When the solenoid valve group is switched to the first working position, the water inlet and the water outlet of the solenoid valve group are connected in the following manner: the first water inlet is isolated from each water outlet, the second water inlet is only connected to the second water outlet, and the third water inlet is only connected to the first water outlet; When the solenoid valve group is switched to the second working position, the water inlet and the water outlet of the solenoid valve group are connected in the following manner: the first water inlet is only connected to the first water outlet, the second water inlet is only connected to the third water outlet, and the third water inlet is isolated from each water outlet; The volume box is provided with a flow scale for indicating the water volume in the box, the upper end of the volume box is provided with a water inlet, and the lower end of the volume box is provided with a drain, one of the volume boxes is a first volume box, and the other volume box is a second volume box; The first water inlet of the solenoid valve group is connected to the drain port of the first volume tank, the second water inlet of the solenoid valve group is connected to the external drainage pipe of the precipitation well, and the third water inlet of the solenoid valve group is connected to the drain port of the second volume tank; The first water outlet of the solenoid valve group is connected to the drainage point outside the precipitation well through a pipe, the second water outlet of the solenoid valve group is connected to the water inlet of the first volume tank, and the third water outlet of the solenoid valve group is connected to the water inlet of the second volume tank; The first volume box and the second volume box are both provided with liquid level sensors, and the signal output ports of the liquid level sensors in the two volume boxes are respectively connected to the control ports of the solenoid valve group, so as to control the solenoid valve group to switch the working position, and the signal output port of the liquid level sensor in the second volume box is connected to the counting signal input port of the counter, so as to trigger the counter to count; When the liquid level sensor in the first volume tank detects that the water level in the tank reaches the position of the liquid level sensor, the liquid level sensor can output a corresponding signal to the control port of the solenoid valve group, thereby triggering the solenoid valve group to switch to the second working position; When the liquid level sensor in the second volume tank detects that the water level in the tank reaches the position of the liquid level sensor, the liquid level sensor can output a corresponding signal to the control port of the solenoid valve group and the counting signal input port of the counter, thereby triggering the solenoid valve group to switch to the first working position and triggering the counter, so that the count value of the counter increases by 1.

2. The flow metering device for a low-flow precipitation well according to claim 1, Features: It also includes a remote monitoring terminal, a flow acquisition module, and water level gauges in both volume boxes; The flow acquisition module is used to collect water level data from two water level meters and send it to a remote monitoring terminal. The two data acquisition ports of the flow acquisition module are respectively connected to the water level data output ports of the two water level meters, and the flow acquisition module is connected to the remote monitoring terminal via a communication network.

3. The flow metering method of the flow metering device for the low flow precipitation well according to claim 2, Features: The total flow rate of drainage outside the precipitation well is calculated as follows: Q t =Q t-dt +S×(max(H1 t -H1 t-dt ,0)+max(H2 t -H2 t-dt ,0)) In the formula, Q t is the total drainage flow of the precipitation well at time t, Q t-dt is the total drainage flow of the precipitation well at time t-dt, dt is the preset water level data collection interval, S is the bottom area of ​​the volume box, H1 t is the water level of the first volume tank at time t, H1 t-dt is the water level of the first volume tank at time t-dt, H2 t is the water level of the second volume tank at time t, H2 t-dt is the water level of the second volume tank at time t-dt, and max() is the maximum value function.

4. The metering method of the flow metering device for the low-flow precipitation well according to claim 2, Features: According to the calculation results of the total flow of drainage outside the precipitation well, the average flow of drainage outside the precipitation well is further calculated. The calculation formula is: In the formula, is the average flow rate of drainage outside the precipitation well, Q t1 is the total flow rate of drainage outside the precipitation well at time t1, Q t2 is the total flow of drainage outside the precipitation well at time t2, and t1 and t2 are two total flow measurement time points.

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