[0036] The technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.
[0037] like figure 1 and 2 As shown in the figure, a durability test device for a water meter provided by the present invention includes: a circulating water tank, a vertical water pump 1, a flow meter 6, a PLC controller 13, a touch display screen, a meter clamp 4, a constant torque frequency converter 14. Vector type motor 15, first temperature sensor 3 and second temperature sensor 12, pressure sensor 2, and liquid level sensor 7;
[0038] The circulating water tank is communicated with the water inlet of the vertical water pump 1 through the first pipeline, the water outlet of the vertical water pump 1 is communicated with the water inlet of the meter clamp 4 through the second pipeline, and the water outlet of the meter clamp 4 is connected through the third pipe. The road is communicated with the circulating water tank, and the measured water meter 5 is clamped by the meter clamp 4; a first temperature sensor 3 and a pressure sensor 2 are arranged on the second pipeline and near the water inlet of the meter clamp 4; on the third pipeline and A flow meter 6 is provided near the water outlet of the clamp 4; a second temperature sensor 12 and a liquid level sensor 7 are provided in the circulating water tank; the circulating water tank is also communicated with the normal temperature water tank through the water inlet valve 8, and the bottom of the circulating water tank is drained The valve 9 is communicated with the drain pipe;
[0039] The PLC controller 13 is respectively connected with the touch screen, the first temperature sensor 3 , the second temperature sensor 12 , the pressure sensor 2 , the liquid level sensor 7 , the flow meter 6 , the constant torque inverter 14 , the water inlet valve 8 and the drain valve 9 Connection; the constant torque inverter 14 is connected with the vector motor 15 , and the vector motor 15 is connected with the vertical water pump 1 . In this embodiment, the installation of the water meter on the meter clamp is the prior art, and reference may be made to the patent document with the application number CN201721695582.5, titled water meter sewage environment abrasion resistance detection equipment.
[0040] In the test device in this embodiment, relevant parameters (including the upper and lower limits of the water temperature in the circulating water tank, the upper and lower limits of the pressure, the total running time of the device, the total number of on-off times and early warning information, etc.) are set on the touch screen. After starting, the vector motor 15 drives the vertical water pump 1 to pump water from the circulating water tank into the pipeline, flows through the measured water meter 5, and returns to the circulating water tank after passing through the flow meter 6. image 3 The device uses the constant torque inverter 14 supporting the vector motor 15 to drive the vertical water pump 1, the freewheeling part of the continuous flow test, the vertical water pump 1 normally supplies water; the cut-off part of the intermittent flow test, the constant torque The frequency converter 14 adopts the resistance braking method to instantaneously brake the vertical water pump 1 to achieve the purpose of cutting off the flow. There is no need to install a shut-off valve on the pipeline. The intermittent flow test realizes no valve start and stop. The maintenance frequency of the device is reduced, and the test cost is reduced.
[0041] The device runs uninterruptedly according to the set relevant parameters, and the water temperature in the circulating water tank is monitored by the second temperature sensor 12. When the water temperature reaches the upper limit, the water inlet valve 8 and the drain valve 9 of the circulating water tank are opened, and the normal temperature water enters the circulating water tank. At the same time, the high-temperature water in the circulating water tank is discharged, the water temperature gradually decreases, and the test continues; when the water temperature drops to the lower limit, the water inlet valve 8 and the drain valve 9 of the circulating water tank are closed; the device is realized by monitoring the water temperature and liquid level. The automatic water exchange function of the circulating water tank avoids the excessive flow of water caused by manual control of the valve to waste water and overflow accidents, and the flow is too small to effectively cool the water body, which affects the test results. Since the water inlet and outlet flows controlled by the water inlet valve 8 and the drain valve 9 are limited by the working conditions and cannot be completely equal, it is necessary to combine the upper and lower limit values of the liquid level for safety control: when the water temperature reaches the upper limit When the liquid level rises to the upper limit, close the water inlet valve 8 and the drain valve 9 is normally open; if the liquid level drops to the lower limit, close the drain valve 9 first, if the circulating water tank is entering water at this time, the Keep the water inlet valve 8 open, and close the water inlet valve 8 when the liquid level reaches the upper limit.
[0042] In this embodiment, a fourth manual ball valve 18 is provided on the first pipeline, a first manual ball valve 10 is provided on the second pipeline between the first temperature sensor 3 and the watch clamp 4, and the watch clamp 4 and the watch clamp 4 are provided with a first manual ball valve 10. A second manual ball valve 16 is arranged on the third pipeline between the flowmeters 6 and a third manual ball valve 17 is arranged on the third pipeline between the flowmeter 6 and the circulating water tank; Adjust to the preset value (that is, the flow value required for the test), and perform a flow adjustment at the beginning of each test.
[0043] In this embodiment, the electrical control part of the test device includes a PLC controller, a touch screen, an analog module, a communication module, a constant torque inverter, a vector motor, a temperature sensor, a pressure sensor, a flowmeter and various valves Wait. The PLC controller uses RS422 to communicate with the touch screen through the programming port; the PLC controller uses the internal control bus to connect with the analog module, communication module, etc.; the analog module communicates with the standard analog signal (4-20) mA or ( 0-10) The first temperature sensor and the second temperature sensor of V output are connected with the pressure sensor; the PLC controller uses RS485 to control the start and stop operation of the constant torque inverter and collect the fault information of the constant torque inverter; The inverter provides variable frequency power supply to the vector motor to drive the vertical water pump; the output signal of the PLC controller is used to control the opening and closing of the water inlet valve and the drain valve; the output switch signal of the liquid level sensor is sent to the PLC controller; the flow rate The open-collector pulse signal output by the meter is sent to the PLC controller.
[0044] The model of the analog module is FX3u-4AD-ADP. The analog input adapter of this model can perform 4-channel voltage input (DC: (0~10)V) or current input (DC: (4~20)mA), And data can be transferred without dedicated instructions. The model of the communication module is FX3u-485ADP-MB, the communication module of this model supports Modbus485 communication, and the program is more concise. The model of PLC controller is FX3u-32AMT/ES-A. FX3u series PLC controller has high-speed processing capability. It can be expanded to meet the required functions of the test in conjunction with the analog module and communication module, providing flexibility and flexibility for the durability test of water meters. control ability. The model of the touch screen is GS2110. The screen has a simple interface, powerful functions and easy operation. It has a built-in USB interface and supports SD data storage cards. The model of the constant torque inverter is FR-A840-00126. The inverter has first-class driving performance. During real-time sensorless vector control, the operating frequency can reach 400Hz, and it has the ability to start with large torque. The model of the vector motor is YVF2-2P-3KW-B14. The Siemens YVF2 series motors can be used together with frequency converters at home and abroad. They are reliable in operation and easy to maintain. They are also equipped with an axial flow fan, which has better cooling at different speeds. Effect.
[0045] To complete the durability test of a set of water meters, the device needs to run continuously for about 1.5 months 24 hours a day. The PLC controller is connected to the terminal through the wireless DTU module, and the terminal can realize remote monitoring of water temperature and liquid level, remote prompt alarm and power on and off. Wait, after setting the relevant parameters, the entire test process can be completed automatically, and the relevant test data will be sent to the terminal regularly for reference by the test personnel, without the need for personnel to check regularly, saving manpower and material resources and improving efficiency. In this embodiment, the terminal includes a mobile phone APP, a web browser, a WeChat applet, and a mailbox.
[0046] In this embodiment, the technical indicators of the test device are combined with the requirements of the national standard "GB/T 778.2-2018/ISO 4064-2:2014 Drinking cold water and hot water meters Part 2: Test methods" and the water meter durability test device determined by the configuration.
[0047] 1. Intermittent flow test
[0048] Measuring diameter range: DN15mm, DN20mm, DN25mm
[0049] Measuring flow range: (1 ~ 8) m 3 /h
[0050] Test water temperature range: (20±5)℃ Test pressure range: (0.1~1.0)MPa
[0051] Test flow accuracy: Q 3 ±5%
[0052] Test on or off time: 1s
[0053] The duration of test water supply or water stop: 15s
[0054] 2. Continuous flow test
[0055] Measuring diameter range: DN15mm, DN20mm, DN25mm
[0056] Measuring flow range: (1 ~ 8) m 3 /h
[0057] Test water temperature range: (20±5)℃
[0058] The maximum allowable working pressure of the device: 1.0MPa
[0059] Test flow accuracy: Q 4 ±5%
[0060] Instantaneous flow stability: better than 2%
[0061] The present invention also provides a method for performing a water meter durability test using any one of the water meter durability test devices in the present embodiment, including:
[0062] Step 1: Set the relevant parameters of the test, including the upper and lower limit values of the water temperature in the circulating water tank, the upper and lower limit values of the liquid level in the circulating water tank, and the upper and lower limit values of the water pressure in the pipeline , the preset time of continuous flow, the total running time of the test and the total on-off times of the test;
[0063] Step 2: Control the operation of the constant torque inverter and the vector motor to control the water supply of the vertical water pump: in the continuous flow test, the vertical water pump will supply water normally until the preset time of the continuous flow is reached; in the intermittent flow test, continue In the flow part, the vertical water pump is like the normal water supply during the continuous flow test; in the cut-off part, the constant-torque inverter adopts the resistance braking method to instantaneously brake the vertical water pump through the vector motor to achieve the purpose of cut-off;
[0064] Step 3: Control the water temperature in the circulating water tank to be between the upper limit value and the lower limit value of the water temperature;
[0065] Step 4: Adjust the opening of the manual ball valve so that the flow displayed by the flow meter reaches the flow value required for the test;
[0066] Step 5: Record the displayed values of the first temperature sensor and pressure sensor once a day, and record the daily accumulated water volume of each measured water meter;
[0067] Step 6: After reaching the total running time of the test or the total number of on-off times, stop the test.
[0068]When the water temperature, liquid level, flow value and pressure value in the pipeline, test running time and test on-off times reach the set value of step 1, the PLC controller will send an early warning message to the terminal, and carry out according to the preset program. Automatic processing or shutdown.
[0069] In step 3, the specific control process of the water temperature in the circulating water tank is as follows: when the water temperature reaches the upper limit and needs to be cooled, the water inlet valve and the drain valve of the circulating water tank are opened, the normal temperature water enters the circulating water tank, and the high temperature water in the circulating water tank is simultaneously Discharge, the water temperature gradually decreases; when the water temperature drops to the lower limit, close the water inlet valve and drain valve of the circulating water tank. Because the water inlet and outlet flow controlled by the water inlet valve and the drain valve are limited by the working conditions and cannot be completely equal, it is necessary to combine the upper limit and lower limit of the liquid level for safety control: when the water temperature reaches the upper limit, it needs to be controlled safely. When cooling, if the liquid level rises to the upper limit, close the water inlet valve and the drain valve is normally open; if the liquid level drops to the lower limit, close the drain valve first, if the circulating water tank is entering water at this time, it will still keep the inlet valve. The water valve is opened, and when the liquid level reaches the upper limit, the water inlet valve is closed.
[0070] The above disclosure is only the specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. should be included within the protection scope of the present invention.
