CN206223265U - The quality demarcation system of mass flowmenter - Google Patents

Abstract

The utility model provides a mass calibration system of a mass flowmeter, which comprises: a calibration solution device, which is used to provide the solution required for calibration of the mass flowmeter; a solution pump, which is used to make the calibration solution flow in the calibration pipeline; A plurality of mass flowmeters to be tested are evenly installed on the calibration pipeline; the actuator switch is used to adjust the flow rate of the calibration solution in the calibration pipeline, and is also used to adjust the mass flow rate in the calibration pipeline per unit time; the standard meter is used to To provide reference data for the mass flow of the calibration solution in the calibration pipeline; the computer, which respectively receives the mass flowmeter, the standard meter, the actuator switch and the electronic scale; it is used to generate a control signal to adjust the actuator switch according to the reference data, and Read the mass flow of the mass flowmeter to be tested and the standard meter according to the electronic scale; the electronic scale is used to measure the flow quality overflowed from the measuring tube of the mass flowmeter. The utility model improves the mass calibration precision and efficiency of the mass flow meter.

Description

Mass Calibration System for Mass Flow Meter

technical field

The utility model belongs to the technical field of instrument correction, in particular to a mass calibration system of a mass flow meter.

Background technique

The Coriolis force mass flowmeter is an instrument developed and designed by applying the principles of fluid mechanics. It is mainly used to measure the mass flow and density of gases and liquids, as well as the volume flow, total mass, and mass flow derived from mass flow and density. Parameters required for projects such as total volume. At this stage, Coriolis force mass flowmeters can be used not only for various conventional fluids, but also for various unconventional fluids, slurries, liquefied gases and compressed natural gas, which are widely used in petrochemical, papermaking, food and pharmaceuticals, etc. industry, its measurement accuracy is usually between 0.1-0.5%. Therefore, for manufacturers of Coriolis force mass flowmeters, it is not only necessary to continuously improve the design, production and processing of Coriolis force mass flowmeter sensors, but also to improve the quality of Coriolis force mass flowmeters. The calibration system of the flowmeter instrument should also be scientifically and rationally improved. Any production link of the complete Coriolis force mass flowmeter product, including the selection and welding of the converter device, the machining of the sensor shunt, the shaping and welding of the measuring tube, the design of the calibration system pipeline and the selection of calibration equipment, etc. It will be related to the linearity, stability, repeatability, accuracy, temperature drift, etc. of the final Coriolis mass flowmeter; therefore, it is necessary to verify the accuracy and practicality of the Coriolis mass flowmeter product and its detection and calibration system. Sexual issues, then it is necessary to separate the two to verify. If you want to test the accuracy, repeatability, stability and other related parameters of the Coriolis force mass flowmeter, then you should have a detection and calibration system that meets the national standard; on the contrary, if you want to test the Coriolis force mass flowmeter calibration system Accuracy, repeatability, stability and other related parameters, then there should be equipment that meets the calibration measurement accuracy of the Ollie force mass flowmeter, and the overall design error of the entire calibration system is much lower than that of the Coriolis force mass flow rate The actual application accuracy of the meter. Only in this way can we design a reasonable and scientific automatic instrumentation and its calibration system.

As shown in Figure 1, it is a schematic structural diagram of an existing Coriolis force mass flowmeter calibration system, wherein the calibration solution device is used to hold the calibration medium solution; the solution pump provides source power for the calibration medium solution , to ensure that the calibration medium solution can flow smoothly in the calibration pipeline; the flow direction switch, the switch to control the flow of the calibration medium solution in the calibration pipeline; the calibration pipeline, the channel through which the calibration medium solution flows; the mass flow meter, which is the Coriolis force mass Flowmeter; fixed base frame, fixedly clamping the cement pile of the Coriolis force mass flowmeter to be calibrated; the flow control switch, whose opening is adjusted by manual adjustment, the purpose of which is to adjust the mass flow rate of the medium solution in the calibration pipeline Size; electronic scale, to measure the quality of the medium solution passing through the mass flow measuring tube; drain switch, a manual switch to discharge the medium solution in the electronic scale.

The calibration method flow chart of the calibration system in Fig. 1 is described in detail as follows:

Step 1, turn off the flow direction switch, install the mass flowmeter to be calibrated on the calibration pipeline as shown in Figure 1, and make the calibration pipeline and the mounting flange of the mass flowmeter in a sealed state without leakage. At the same time, ensure that the mass flowmeter The shell is perpendicular to the ground;

Step 2, turn on the solution pump, adjust the flow direction switch, flow control switch and electronic scale drain switch to the maximum opening, so that the calibration medium solution flows in the calibration tube at the maximum flow rate, and maintain this state for at least 20 minutes. The purpose is to make the calibration The medium solution fills the entire calibration pipeline to remove the air in the pipeline;

Step 3, turn off the flow direction switch and the flow control switch, and set the mass flowmeter converter to be calibrated on the calibration pipeline to the automatic zero calibration state until it completes the automatic zero calibration;

Step 4, adjust the flow rate control switch to the full opening state, when the flow rate of the calibration solution is stable, record the maximum phase difference corresponding to the sensor measuring tube when the current mass flowmeter sensor to be calibrated is at the maximum flow rate;

Step 5. Based on the maximum phase difference corresponding to the sensor measuring tube at the maximum flow rate, select the flow calibration points of the mass flowmeter to be calibrated, which are 1.0, 0.9, 0.8, and 1.0 of the maximum phase difference of the sensor measuring tube at the maximum flow rate. 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.05 and 0.02 times points;

Step 6: Adjust the opening of the flow control switch so that the opening meets the point where the flow of the calibration solution in the calibration pipeline can cause the mass flowmeter sensor measuring tube to produce 1.0 times the maximum phase difference, and close the flow direction switch at the front of the calibration pipeline until Calibrate until the electronic weighing end of the calibration pipeline has no calibration solution dripping;

Step 7, turn on the flow direction switch at the front section of the calibration pipeline, when the maximum phase difference corresponding to the sensor measuring tube is 1.0 times when the calibration mass flowmeter sensor is at the maximum flow rate, delay the calibration measurement for 7-10 minutes, and turn off the flow direction switch, Until there is no calibration solution dripping from the electronic weighing end of the calibration pipeline, record the total amount of metering mass on the converters of all mass flowmeters to be calibrated and the total amount of metering on the electronic scale;

Step 8, repeat steps 6 to 7 to complete the calibration of other phase difference calibration points;

Step 9: Calculate the mass flow coefficient corresponding to each mass flow meter to be calibrated according to the calibration data, and write the coefficient into the EEPROM of the mass flow meter converter through key operation.

Step 10, performing accuracy detection and repeatability detection of the mass flow meter.

Step 11, adjust the flow rate control switch to the full opening state, and record the maximum mass flow rate output by the mass flowmeter converter on the current calibration pipeline;

Step 12, taking the maximum mass flow rate as the benchmark, respectively selecting points of 1.0, 0.75, 0.50, 0.25 and 0.1 times the maximum mass flow rate as the accuracy detection and repeatability detection points of the mass flow meter;

Step 13, adjust the flow rate control switch to 1.0 times the maximum mass flow rate output by the mass flowmeter converter, delay the measurement for 7-10 minutes, turn off the flow direction switch until there is no solution dripping from the electronic weighing end of the calibration pipeline, and then Record the total mass output of all current mass flowmeter converters to be verified and the total mass measured by the electronic scale;

Step 14, the 1.0 times point of the maximum mass flow rate is repeatedly measured 3 times, and the accuracy and repeatability of the current detection point are calculated;

Step 15, repeat steps 13 to 14 to complete the detection of other mass flow detection points.

In the existing mass flow calibration system of Coriolis force mass flow meters, the mass flow calibration of two mass flow meters can be accommodated at most. The ground coefficient, as well as the accuracy and repeatability detection data when the calibration is completed, require manual operation, which will inevitably affect the accuracy and repeatability of the whole instrument. In addition, a large number of experiments and tests have shown that in the calibration system of the solution pump and the calibration pipeline during the production calibration process, there is always a certain amount of air bubbles brought into the calibration pipeline, and the work of the solution pump will also cause the calibration pipeline to leak. The calibration solution produces a trickle phenomenon, and these factors greatly reduce the accuracy of the mass flow calibration system of the entire mass flow meter.

Utility model content

In view of the above-mentioned shortcomings of the prior art, the purpose of this utility model is to provide a mass flowmeter mass calibration system, which is used to solve the problem that the mass flowmeter in the prior art requires manual operation when calibrating the mass flow rate, resulting in the Low efficiency and low accuracy of flowmeter calibration.

In order to achieve the above purpose and other related purposes, the utility model provides a mass flow meter calibration system, including:

Calibration solution device, which is used to provide the calibration solution required for mass flowmeter calibration; solution pump, which is used to provide power to flow the calibration solution in the calibration pipeline at a certain pressure; standard meter, installed in the calibration pipeline along the output direction of the solution pump It is used to provide reference data for the mass flow of the calibration solution in the calibration pipeline; multiple mass flowmeters to be tested are evenly installed on the calibration pipeline along the output direction of the standard meter; the actuator switch is used to control the calibration pipeline Whether the internal calibration solution flows is also used to adjust the mass flow of the calibration solution in the calibration pipeline per unit time; the computer is connected to the mass flow meter, standard meter, actuator switch and electronic scale; Adjust the opening of the actuator switch, and read the mass flowmeter to be tested according to the electronic scale; the electronic scale, which is connected to the actuator switch, is used to measure the flow quality overflowed from the calibration pipeline of the mass flowmeter.

Preferably, the actuator switch includes a first actuator switch and a second actuator switch, and the first actuator switch is installed on the calibration pipeline between the standard gauge and the solution pump, which is used for outputting the first actuator switch according to the computer. The control signal controls whether the calibration solution in the calibration pipeline flows; the second actuator switch is installed on the calibration official road between the electronic scale and the mass flow meter close to it, and it is used to adjust the calibration pipeline according to the second control signal output by the computer The mass flow rate of the internal calibration solution per unit time.

Preferably, a constant pressure and constant flow tank is provided between the solution pump and the actuator switch, which is used to eliminate the trickle in the calibration solution and the air bubbles in the calibration solution.

Preferably, both sides of each mass flow meter and standard meter are provided with fixed racks for supporting their work.

Preferably, the electronic scale is connected with a drainage control valve controlled by the computer.

Preferably, the computer is respectively connected to the actuator switch, the standard meter, the mass flow meter, the electronic scale and the drainage control valve through a control bus.

Preferably, the number of the mass flow meters to be tested is at most five.

As mentioned above, the calibration system of the mass flowmeter of the present invention has the following beneficial effects:

By replacing the original manually operated calibration system with a computer-controlled calibration system, the computer sends control signals to adjust the opening of the actuator switch to control the flow rate of the calibration solution in the calibration pipeline. Two mass flowmeters are calibrated, but now five sets can be calibrated at the same time, and no human participation is required in the calibration process, which not only improves the efficiency of mass flowmeter calibration, but also greatly improves the calibration accuracy of mass flowmeters; at the same time, in The constant pressure and constant flow tank is introduced into the calibration system, which eliminates the trickle of calibration solution and air bubbles caused by the solution pump when it is working, and essentially improves the calibration accuracy of the mass flowmeter.

Description of drawings

Fig. 1 shows the structural representation of the existing Coriolis force mass flowmeter calibration system provided for the utility model;

Fig. 2 shows a block diagram of a calibration system of a mass flowmeter of the present invention;

Fig. 3 is a structural diagram of an embodiment of a calibration system for a mass flowmeter of the present invention.

detailed description

The implementation of the present utility model is illustrated by specific specific examples below, and those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification.

Please refer to Figure 2 to Figure 3. It should be noted that the structures, proportions, sizes, etc. shown in the drawings attached to this specification are only used to match the content disclosed in the specification, for those who are familiar with this technology to understand and read, and are not used to limit the implementation of the utility model Therefore, it has no technical substantive meaning. Any modification of structure, change of proportional relationship or adjustment of size shall still fall within the scope of The technical content disclosed by the utility model must be within the scope covered. At the same time, terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit this specification. The practicable range of the utility model, and the change or adjustment of its relative relationship, without any substantial change in the technical content, shall also be regarded as the practicable scope of the utility model.

Please refer to Figure 2, the utility model provides a structural block diagram of a mass flowmeter calibration system, including:

Calibration solution device 1, which is used to provide the calibration solution required for mass flowmeter calibration; solution pump 3, which is used to provide power to flow the calibration solution in the calibration pipeline at a certain pressure; standard gauge 4, installed along the output direction of the solution pump On the calibration pipeline, it is used to provide reference data for the mass flow of the calibration solution in the calibration pipeline; a plurality of mass flowmeters 5 to be measured are evenly installed on the calibration pipeline along the output direction of the standard meter 4; the actuator switch 2, It is used to control whether the calibration solution in the calibration pipeline flows, and is also used to adjust the mass flow rate of the calibration solution in the calibration pipeline per unit time; the computer 6 is connected to the mass flow meter 5, the standard meter 4, the actuator switch 2 and the electronic Scale 7; it is used for adjusting the opening degree of actuator switch 1 according to the size of reference data, and reads the mass flowmeter 5 to be tested according to said electronic scale 7; electronic scale 7, it is connected to said actuator switch 2 , used to measure the mass flow meter 5 to calibrate the flow quality overflowed from the pipeline.

In this embodiment, the mass flow meter 5, the standard meter 4, the actuator switch 2, and the electronic scale 7 are automatically controlled by the computer. The entire calibration process does not require manual participation, eliminating artificial unstable factors, and not only improving the calibration efficiency. Calibration accuracy is also improved.

Specifically, the actuator switch 2 includes a first actuator switch and a second actuator switch. The first actuator switch 2 is installed on the calibration pipeline between the standard meter and the solution pump, and it is used for The first control signal controls whether the calibration solution in the calibration pipeline flows; the second actuator switch 2 is installed on the calibration official road between the electronic scale and the mass flow meter close to it, and it is used for outputting the second control signal according to the computer Adjust the mass flow rate of the calibration solution in the calibration pipeline per unit time.

On the basis of the above structure, a constant pressure and constant flow tank can also be provided between the solution pump 3 and the actuator switch 2, and the input end of the constant pressure and constant flow tank is connected to the output calibration pipeline of the solution pump 3. The output end of the constant pressure and constant flow tank is connected to the actuator switch 2 through the calibration pipeline, and the constant pressure and constant flow tank is used to eliminate the trickle in the calibration solution and the air bubbles in the calibration solution.

Specifically, both sides of each of the mass flowmeter 5 and the standard meter 4 are provided with a fixed frame for supporting its work, that is, there are fixed frames on both sides of the standard meter and both sides of the mass flowmeter, and the fixed frame The frame is preferably a cement frame. It can not only eliminate the influence of the vibration of the calibration pipeline on the mass flow calibration instrument, but also eliminate the influence of the mass flow sensor’s own mechanical vibration on the mass flow calibration. At the same time, the fixed frame is also used to isolate the mass flowmeters of the whole machine to be calibrated online, and prevent the mutual influence between the mass flowmeters of the whole machine to be calibrated.

Specifically, the electronic scale 7 is connected with a drain control valve controlled by the computer, and the drain control valve is connected to the computer 6 by bus control, and the switch of the drain control valve is controlled according to the control signal sent by the computer, such as: During the calibration process of the mass flowmeter, the drain control valve is always closed; every time the mass flowmeter is calibrated, the drain control valve is opened until the mass flow in the electronic scale is exhausted.

Specifically, the computer 6 is respectively connected to the actuator switch 2, the standard meter 4, the mass flow meter 5, the electronic scale 7 and the drainage control valve through the control bus; The bus control method, and reading the reference data in the standard table as the control basis for controlling the actuator switch 2, that is, the basis for the regulator to control and adjust the opening of the actuator switch mainly depends on the instantaneous mass flow rate output by the standard meter, and the standard meter If the instantaneous mass flow rate of the metering output is small, the opening of the second actuator switch is small; otherwise, if the instantaneous mass flow rate of the metering output of the standard meter is large, the opening of the second actuator switch is large, which can improve the control accuracy of the actuator switch.

Moreover, the number of the mass flowmeters 5 to be tested is five at most, compared with the original calibration system, which can only calibrate two mass flowmeters at most, which improves the calibration efficiency.

As shown in Figure 3, it is a structural diagram of an embodiment of a calibration system of a mass flowmeter of the present invention, including:

In this embodiment, the calibration solution device 1 provides the solution pump 3 with the calibration solution required for calibration, and the solution pump 3 ensures that the calibration pipelines in the entire calibration system are constant flow under the action of the constant pressure and constant flow tank. Constant pressure can eliminate the impact of a large number of bubbles in the calibration solution on the calibration accuracy; the computer 6 is connected to the first actuator switch, the second actuator switch, the standard meter 4, and five to-be-measured (to be calibrated) through the bus control control The mass flowmeter 5, the electronic scale 7, and the drainage control valve are all connected to each other through calibration pipes. The standard meter and the five mass flowmeters to be tested are respectively arranged along the constant pressure and constant flow path from left to right. The output direction of the tank is evenly distributed on the calibration pipeline, and there is a supporting fixed rack under the calibration pipeline (as above, not repeating them one by one here); each time the calibration is performed, the second actuator is controlled by reading the reference data of the standard table The basis for the size of the switch opening; by controlling the first actuator switch to open and stop the switch of the calibration solution flow and stop flow in the calibration pipeline; and the computer records the flow quality of the electronic scale for each calibration, according to the corresponding multiple points The flow quality calculates the mass flow coefficient of each mass flow meter, and saves the mass flow coefficient to the corresponding mass flow meter; at the same time, controls the opening of the drainage control valve to clear the calibration solution of the electronic scale to prepare for the next calibration.

In this embodiment, the process flow of the above-mentioned calibration method for the mass flowmeter is adopted, including:

Step 1, set the aperture value and upper limit value according to the type of mass flowmeter to be tested;

Step 2, adjust the first actuator switch and the second actuator switch until the mass flowmeter to be tested has no leakage;

Step 3, when both the first actuator switch and the second actuator switch are adjusted to the full opening, keep this state for at least ten minutes (until there are almost no air bubbles in the calibration pipe, standard meter and mass flowmeter measuring tube) ;

Step 4, when both the first actuator switch and the second actuator switch are adjusted to zero opening, obtain the current first reading of the standard meter; check whether the calibration solution in the calibration pipeline is in a flowing state, if the calibration solution is not In the flow state, broadcast an automatic zero calibration command to the mass flowmeter to be tested, and adjust the drain control valve to be closed until the automatic zero calibration is completed;

Step 5, select the calibration point of the mass flowmeter according to the type and range of the mass flowmeter to be tested, and select the multiple point of the range as the selection point for the calibration point, wherein the multiple point includes 1.0, 0.9, 0.8, 0.7, 0.6 , 0.5, 0.4, 0.3, 0.2, 0.1, 0.05 and 0.02;

Step 6: Calibrate with a selected point as the mass flow calibration point, adjust the first actuator switch to the full opening, and obtain the current second reading of the standard meter; according to the mass flow rate corresponding to the second reading close to the selected point Adjust the opening of the second actuator switch until the mass flowmeter to be tested reaches the mass flow calibration point corresponding to the selected point;

Step 7, adjust the opening of the first actuator switch to zero, and keep the opening of the second actuator switch unchanged (at least two minutes), until there is no calibration solution dripping between the calibration pipeline and the electronic scale;

Step 8, clear the standard meter and the total mass output by the mass flowmeter to be tested, and record the reading of the current electronic scale and clear it;

Step 9, adjusting the first actuator switch to the full opening, delaying the mass flowmeter to be measured at the multiple point corresponding to the selected point as the mass flow calibration point according to the preset time delay;

Step 10, adjust the first actuator switch to zero opening, obtain whether the current reading of the standard meter is zero, if the current reading of the standard meter is zero and there is no calibration solution dripping between the calibration pipeline and the electronic scale, obtain And record the total mass output by each mass flowmeter to be tested and the total mass of the electronic scale calibration solution;

Step 11, repeat steps 6 to 10, and complete the calibration of the mass flow calibration points of other selected points in turn; calculate the mass flow coefficient of each mass flow meter according to the calibration data, and store the mass flow coefficient in the mass flow meter to be tested .

Step 12, re-select the range multiple point of the mass flowmeter as the selected point, perform accuracy and repeatability detection for each selected point according to steps 6 to 11, and record the calibration and detection results of the mass flowmeter to be tested.

According to the calibration method of the above-mentioned mass flowmeter, the details are as follows:

1. Initialize the mass flow meter mass flow calibration system in the computer, select a new round of mass flow calibration, and select and set the caliber and mass flow rate of the mass flow meter to be calibrated according to the type of mass flow meter sensor to be calibrated in actual production Calibrated upper limit;

2. Control the first adjustment actuator switch and the second actuator switch to the closed state, that is, the opening is 0;

3. Check whether the constant pressure and constant flow tank is in the state of full tank and constant pressure. If it is not in the state of full tank and constant pressure, turn on the exhaust switch on the constant pressure and constant flow tank device, so that the calibration solution supplied by the solution pump can be filled to the maximum extent. Close the exhaust switch after the constant pressure and constant flow tank, the purpose is to eliminate the existence of air bubbles in the calibration solution and the non-constant pressure and constant flow state of the calibration solution;

4. Install the mass flowmeter to be calibrated on the calibration pipeline. The calibration system can accommodate up to 5 complete mass flowmeters. If there are less than 5 units, use the method of direct connection with the pipeline;

5. Control and adjust the actuator switch 1 and actuator switch 2 to the 50% opening point, and observe whether there is any leakage at the flange connection between the calibration pipe and the mass flow meter of the whole machine; if there is no leakage, pass the mass flow calibration The system software controls and adjusts the switch of the first actuator and the switch of the second actuator to the point where the opening is 100%, and observes again whether there is any leakage at the flange connection between the calibration pipe and the mass flow meter of the whole machine; if there is still no leakage, then Continue to work for about 5 minutes, and adjust the first actuator switch and the second actuator switch to the closed state through the software control of the mass flow calibration system. If leakage occurs during installation and inspection, human intervention is required for reinstallation.

6. Start the mass flow calibration process of the mass flow calibration system software;

7. Control and adjust the actuator switch 1 and actuator switch 2 to the point where the opening is 100%, so that they can continue to work in this state for 10 minutes. This process is to make the calibration solution fully fill the calibration pipe and the standard meter, and the mass flow rate to be calibrated In the measuring tube of the gauge sensor, the influence of air bubbles on the accuracy is eliminated;

8. Control and adjust the actuator switch 1 and actuator switch 2 to the point where the opening is 0%, and then obtain the real-time output status of the standard meter through the data bus, and monitor whether there is a solution flow state in the calibration pipeline. If there is no solution flow, the mass flow rate The calibration system software sends a broadcast to all online mass flowmeters to be calibrated for automatic zero-calibration quality, and at the same time controls the drainage control valve to be closed, and waits for the zero-calibration to be completed;

9. Select the calibration point according to the sensor type and range of the mass flowmeter to be calibrated, usually choose 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1 of the mass flow range of the mass flowmeter to be calibrated , 0.05 and 0.02 points are the selected points for mass flow calibration;

10. Carry out the calibration of the mass flow calibration point whose mass flow range is 1.0 times of the mass flowmeter to be calibrated. The mass flow calibration system software controls and adjusts the actuator switch 1 to the 100% opening point, obtains the real-time mass flow output value of the standard meter through the data bus, and depends on whether the actual mass flow output value reaches or is close to the quality of the mass flowmeter to be calibrated Adjust the opening of the actuator switch 2 at the mass flow rate of 1.0 times the flow range, so that the opening meets the calibration point of the mass flow rate of the mass flow meter to be calibrated at 1.0 times the mass flow range;

11. Control and adjust the actuator switch 1 to be in the closed state, and the opening of the actuator switch 2 remains unchanged, with a delay of 2 minutes; the purpose of the delay is to wait until there is no calibration solution dripping between the calibration pipe terminal and the electronic scale;

12. Clear the total mass of the standard meter and the mass flowmeter to be calibrated, and record and clear the total mass value of the electronic scale’s measurement output (record the total mass of each electronic scale’s measurement output, and record the total mass of each measurement. Add up to judge whether the accumulated total amount reaches or is close to the limit value of the weighing scale. If it reaches or is close to the limit value, the mass flow calibration system software controls the drainage control valve to be in the open state through the control bus, and carries out the electronic weighing measurement solution. discharge all, and at the same time clear the cumulative total in the mass flow calibration system software).

13. Control and adjust the opening state of the actuator switch from 1 to 100%, carry out the calibration of the mass flow calibration point whose mass flow range is 1.0 times of the mass flow meter to be calibrated, and measure the calibration with a delay of 6 minutes (delay time can be set) ;

14. Control and adjust the opening state of the actuator switch from 1 to 0%. Obtain whether the real-time mass flow output value of the standard meter is 0 through the data bus. If it is 0, wait for a delay to calibrate the calibration solution between the pipeline terminal and the electronic scale. When dripping, the software of the mass flow calibration system obtains and records the total mass of the online corresponding to each mass flow meter output measurement and the total mass of the electronic scale measurement calibration solution through the data bus;

15. Repeat steps 10)-14) to complete the calibration of the mass flow at the points of 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.05 and 0.02 times the mass flow meter range to be calibrated online;

16. Quality Calculate the online mass flow coefficient corresponding to each mass flow meter according to the calibration data, and write the coefficient into the EEPROM of the corresponding mass flow meter converter through the data bus.

17. Automatically start the accuracy and repeatability detection of the online mass flowmeter;

18. Usually select 1.0, 0.75, 0.50, 0.25 and 0.1 times of the online mass flowmeter range as the accuracy and repeatability detection points of the mass flowmeter;

19. Perform a mass flow verification point verification with a mass flow rate of 1.0 times. The mass flow calibration system software controls and adjusts the actuator switch 1 to the 100% opening point, obtains the real-time mass flow output value of the standard meter through the data bus, and depends on whether the actual mass flow output value reaches or is close to the mass flow rate of the mass flow meter The mass flow rate is 1.0 times the range to adjust the opening of the actuator switch 2 so that the opening meets the mass flow point where the mass flow rate of the mass flow meter is 1.0 times the range;

20. Control and adjust the actuator switch 1 to be in the closed state, the opening of the actuator switch 2 remains unchanged, and the delay is 2 minutes; the purpose of the delay is to wait until there is no calibration solution dripping between the calibration pipe terminal and the electronic scale;

21. Clear the total mass output from the standard meter and the mass flowmeter to be calibrated, and record and clear the total mass output from the electronic scale at the same time.

22. Control and adjust the opening state of the actuator switch from 1 to 100%, carry out the mass flow point accuracy and repeatability detection with the mass flow rate range of 1.0 times of the mass flowmeter, and the measurement verification with a delay of 6 minutes;

23. Control and adjust the opening state of the actuator switch from 1 to 0%. Obtain whether the real-time mass flow output value of the standard meter is 0 through the data bus. If it is 0, wait for a delay to calibrate the calibration solution between the pipeline terminal and the electronic scale. When dripping, the software of the mass flow calibration system obtains and records the total mass of the online corresponding to each mass flow meter output measurement and the total mass of the electronic scale measurement calibration solution through the data bus;

24. Repeat steps 21)-23) to complete the second accuracy and repeatability detection of the mass flow verification point with a mass flow rate of 1.0 times;

25. Repeat steps 21)-23) to complete the third accuracy and repeatability detection of the mass flow verification point with a mass flow rate of 1.0 times;

26. Repeat steps 19)-25) to complete the detection of the accuracy and repeatability of the mass flow points of 0.75, 0.50, 0.25 and 0.1 times;

27. Report the calibration and testing results (accuracy and repeatability) of online mass flowmeters for production users.

In summary, the utility model replaces the original manually operated calibration system with a computer-controlled calibration system, and uses a computer to send a control signal to adjust the opening of the actuator switch to control the flow rate of the calibration solution in the calibration pipeline. Some calibration systems can only calibrate two mass flowmeters at most, but now five can be calibrated at the same time, and there is no need for human participation in the calibration process, which not only improves the efficiency of mass flowmeter calibration, but also greatly improves the quality. Calibration accuracy of the flowmeter; at the same time, a constant pressure and constant flow tank is introduced into the calibration system, which eliminates the problems of calibration solution trickle and air bubbles produced by the solution pump when it is working, and essentially improves the calibration of the mass flowmeter. precision. Therefore, the utility model effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present utility model, but are not intended to limit the present utility model. Anyone familiar with this technology can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the utility model should still be covered by the claims of the utility model.

Claims (8)

1. A mass calibration system of a mass flowmeter, characterized in that, comprising: Calibration solution device, which is used to provide the calibration solution required for mass flowmeter calibration; Solution pump, which is used to provide power to flow the calibration solution in the calibration pipeline at a certain pressure; The standard meter is installed on the calibration pipeline along the output direction of the solution pump, which is used to provide reference data for the mass flow of the calibration solution in the calibration pipeline; A plurality of mass flowmeters to be tested are evenly installed on the calibration pipeline along the output direction of the standard meter; The actuator switch is used to control whether the calibration solution in the calibration pipeline flows, and is also used to adjust the mass flow rate of the calibration solution in the calibration pipeline per unit time; Computer, which is respectively connected with mass flowmeter, standard meter, actuator switch and electronic scale; it is used to adjust the opening degree of actuator switch according to the size of reference data, and read the mass flowmeter to be tested according to the electronic scale; An electronic scale, which is connected to the actuator switch, is used to measure the flow quality overflowed from the calibration pipeline of the mass flowmeter. 2. The mass calibration system of a mass flowmeter according to claim 1, wherein the actuator switch comprises a first actuator switch and a second actuator switch, and the first actuator switch is installed on a standard meter On the calibration pipeline between the solution pump, it is used to control whether the calibration solution in the calibration pipeline flows according to the first control signal output by the computer; the second actuator switch is installed between the electronic scale and the mass flow meter close to it On the calibration road, it is used to adjust the mass flow rate of the calibration solution in the calibration pipeline in unit time according to the second control signal output by the computer. 3. The mass calibration system of the mass flowmeter according to claim 1 or 2, characterized in that, a constant pressure and constant flow tank is provided between the solution pump and the actuator switch, which is used to eliminate the The trickle and the air bubbles carried in the calibration solution. 4. The mass calibration system for mass flowmeters according to claim 1 or 2, characterized in that, both sides of each mass flowmeter and standard meter are provided with fixed racks for supporting their work. 5. The mass calibration system of mass flowmeter according to claim 1 or 2, characterized in that the computer is respectively connected to the actuator switch, the standard meter, the mass flowmeter and the electronic scale through the control bus. 6 . The mass calibration system for mass flowmeters according to claim 1 , wherein the electronic scale is connected with a drainage control valve controlled by the computer. 7 . 7. The mass calibration system of mass flowmeter according to claim 6, characterized in that, the computer is connected to the drain control valve by a control bus. 8. The mass calibration system for mass flow meters according to claim 1 or 2, characterized in that the number of the mass flow meters to be tested is at most five.