CN210862863U - Gas flowmeter calibrating device - Google Patents
Gas flowmeter calibrating device Download PDFInfo
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- CN210862863U CN210862863U CN202020396576.5U CN202020396576U CN210862863U CN 210862863 U CN210862863 U CN 210862863U CN 202020396576 U CN202020396576 U CN 202020396576U CN 210862863 U CN210862863 U CN 210862863U
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Abstract
The utility model relates to a gas flowmeter calibrating device, which comprises a filtering container component, a pressure stabilizing tank, a confluence container, a flow control pipeline, a stagnation container and a flow measurement pipeline which are connected in sequence; the flow control pipeline comprises a plurality of flow control branches connected in parallel between the confluence container and the stagnation container, and each flow control branch is provided with a first control valve and a Venturi nozzle; the flow measurement pipeline comprises a plurality of flow measurement branches connected in parallel with the stagnation container, a standard gas flowmeter is arranged on each flow measurement branch, and each flow measurement branch is used for being connected with a detected gas flowmeter. The utility model discloses concatenate standard gas flowmeter on every flow measurement branch road, improved the precision of gas flow examination, and can realize the gas flowmeter's of the same bore or different bores batch detection calibration. The gas flowmeter calibrating device comprises a filtering container assembly and a pressure stabilizing tank, so that flow velocity fluctuation and pressure fluctuation in a pipeline are reduced, and the calibrating precision is further improved.
Description
Technical Field
The utility model relates to a flow measurement field, concretely relates to gas flowmeter calibrating installation.
Background
The calibration method of the gas flowmeter can be broadly divided into a direct calibration method and an indirect calibration method according to the calibration principle. The direct calibration method is to obtain the flow of the detected flowmeter by connecting a standard device and the detected flowmeter in series, and compare the flow indication values of the fluid measured by the standard device and the detected flowmeter to obtain the accuracy of the detected flowmeter; indirect calibration is the measurement of a quantity related to the calculated flow, and the flow value is checked indirectly according to a prescribed method to obtain meter accuracy. The accuracy of the direct calibration method is higher than that of the indirect calibration method, mainly because the direct calibration method is connected with a gas flow standard device. The standard device commonly used at present is a venturi nozzle according to the specification of ISO9300 standard "measuring gas flow with a critical flow venturi nozzle", and the uncertainty of measurement using this standard device can reach 0.5%.
The principle of the method for measuring the gas flow rate by the critical flow venturi nozzle is that a flow rate measuring device consisting of a plurality of venturi nozzles is installed on a pipeline, and gas continuously flows through the nozzles and a detected flowmeter at the same time interval. Due to the conservation of mass, the flow rate of the nozzle is the same as that of the flow meter to be detected, and the flow rate indication values of the nozzle and the flow meter to be detected are compared, so that the metering performance of the flow meter to be detected can be determined. The nozzle method is characterized in that a Venturi nozzle is arranged as a standard flowmeter in a standard gas flow rate manner, the Venturi nozzle is very sensitive to pressure fluctuation, only one of a plurality of pipelines connected in parallel can be used in a working state, other pipelines are required to be closed, and a plurality of detected flowmeters cannot be detected and calibrated simultaneously.
With the technical progress in the field of industrial automation, the requirements on the accuracy and stability of the gas flow meter are higher and higher. In order to ensure that the measurement performance of the gas flowmeter meets the requirements, the gas flowmeter needs to be detected and calibrated one by one before being put into use. When the factory batch of the flow meters is large (such as household gas meters, vehicle engine intake flow meters and the like), how to carry out efficient and accurate batch detection and calibration becomes a problem to be solved urgently.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a can high-efficient accurately carry out gas flowmeter's gas flowmeter calibrating installation of examining and determine in batches.
The utility model adopts the following solution:
a gas flowmeter calibrating device comprises a filtering container assembly, a pressure stabilizing tank, a confluence container, a flow control pipeline, a stagnation container and a flow measurement pipeline which are sequentially connected; the flow control pipeline comprises a plurality of flow control branches connected between the confluence container and the stagnation container in parallel, and each flow control branch is provided with a first control valve and a Venturi nozzle; the flow measurement pipeline comprises a plurality of flow measurement branches connected in parallel with the stagnation container, a standard gas flowmeter is arranged on each flow measurement branch, and each flow measurement branch is used for being connected with a detected gas flowmeter.
Preferably, the filter vessel assembly comprises a plurality of filter vessels connected in series.
Preferably, the filter vessel assembly comprises a plurality of filter vessels connected in parallel.
Preferably, each flow measurement branch is further provided with a second control valve, and the second control valve is arranged between the stagnation container and the standard gas flowmeter.
Preferably, the gas flow meter calibrating device further comprises a gas source connected to the filter container assembly for supplying gas to the filter container assembly.
Preferably, each said first control valve is provided between a venturi nozzle and said stagnation vessel.
Preferably, the gas flowmeter calibrating device further comprises a recovery container, wherein the recovery container is connected with each flow measuring branch respectively and is connected with the gas source through a recovery gas pipeline.
Preferably, each of the detected gas flow meters is provided between one of the standard gas flow meters and the recovery tank.
Preferably, the gas flow meter verification device further comprises a vacuum suction device connected to the filter vessel assembly for evacuating air from the filter vessel assembly.
Preferably, each of said first control valves is provided between a venturi nozzle and said confluence vessel.
The beneficial effects of the utility model reside in that: the method has the advantages that a Venturi nozzle is not used as a standard gas flowmeter, only the Venturi nozzle is used for controlling the flow, the defect that the Venturi nozzle is too sensitive to pressure fluctuation is overcome, the characteristic of a critical flow state is utilized, if the pressure at the inlet of the nozzle is not changed, the back pressure at the outlet is reduced, the flow speed is kept unchanged, namely the flow speed is not influenced by the downstream pressure, so that stable flow is obtained, the standard gas flowmeter is connected in series on each flow measurement branch, the accuracy of gas flow verification is improved, and batch detection and calibration of the gas flowmeters with the same caliber or different calibers can be realized. In addition, the gas flowmeter calibrating device also comprises a filtering container assembly and a pressure stabilizing tank, so that the flow velocity fluctuation and the pressure fluctuation in the pipeline are reduced, and the calibrating precision can be further improved.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings. Wherein like reference numerals generally refer to like parts throughout the exemplary embodiments of the present invention.
Fig. 1 shows a schematic structural diagram of a gas flowmeter calibrating apparatus according to a first embodiment of the present invention;
fig. 2 shows a schematic structural diagram of a gas flowmeter calibrating device according to a second embodiment of the present invention;
fig. 3 shows a schematic structural diagram of a gas flowmeter calibrating device according to a third embodiment of the present invention;
fig. 4 shows a schematic structural diagram of a gas flowmeter calibrating device according to a fourth embodiment of the present invention;
fig. 5 shows a schematic structural diagram of a gas flowmeter calibrating device according to a fifth embodiment of the present invention.
Description of reference numerals:
the device comprises a vacuum suction device 1, a filtering container 2, a pressure stabilizing tank 3, a confluence container 4, a first control valve 5, a Venturi nozzle 6, a stagnation container 7, a second control valve 8, a standard gas flowmeter 9, a detected gas flowmeter 10, a recovery container 11 and a gas source 12.
Detailed Description
Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While two exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
In the description of the present invention, it is to be understood that the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "secured" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral part; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.
The utility model provides a gas flowmeter calibrating device, which comprises a filtering container assembly, a pressure stabilizing tank, a confluence container, a flow control pipeline, a stagnation container and a flow measurement pipeline which are connected in sequence; the flow control pipeline comprises a plurality of flow control branches connected in parallel between the confluence container and the stagnation container, and each flow control branch is provided with a first control valve and a Venturi nozzle; the flow measurement pipeline comprises a plurality of flow measurement branches connected in parallel with the stagnation container, a standard gas flowmeter is arranged on each flow measurement branch, and each flow measurement branch is used for being connected with a detected gas flowmeter.
The filtering container assembly comprises a plurality of filtering containers connected in series or in parallel, each filtering container is a hollow container, and the filtering container assembly has the effects of avoiding the fluctuation of flow or flow velocity in a pipeline and blocking the fluctuation of airflow flow, so that the flow state during testing is more stable.
The surge tank is a hollow container with a larger volume, and has the function of avoiding the sudden change of pressure in a pipeline and blocking the fluctuation of air flow pressure, so that the flow state during testing is more stable.
The confluence container is a hollow container and is used for connecting the flow control pipeline and the pressure stabilizing tank and converging the air flow passing through the flow control pipeline.
The flow control pipeline comprises a plurality of flow control branches connected between the confluence container and the stagnation container in parallel, and each flow control branch is provided with a first control valve and a Venturi nozzle which are used for controlling the required flow in a combined mode.
The stagnation container is a hollow container and is used for connecting the flow measuring pipeline and the flow control pipeline and collecting the airflow passing through the flow measuring pipeline or the flow control pipeline.
The flow measurement pipeline comprises a plurality of flow measurement branches connected in parallel with the stagnation container, each flow measurement branch is provided with a standard gas flowmeter and is used for being connected with a detected gas flowmeter, and the pipeline calibers of the flow measurement branches can be the same or different.
According to the utility model discloses a gas flowmeter calibrating installation sets up standard gas flowmeter on every flow measurement branch road of parallelly connected, and every flow measurement branch road is connected one and is examined gas flowmeter, and the pipeline bore of each flow measurement branch road can be the same or different, confirms the measurement performance who is examined gas flowmeter through comparing standard gas flowmeter and the reading of examining gas flowmeter. The utility model discloses do not regard as standard gas flowmeter with the venturi nozzle, only use its control flow, avoided the venturi nozzle too sensitive shortcoming to the pressure oscillation, utilize the characteristics of critical flow state-if nozzle entry pressure is unchangeable, reduce the export backpressure again, then the velocity of flow will remain unchanged, the velocity of flow no longer receives the influence of low reaches pressure promptly-obtains comparatively stable flow, standard gas flowmeter concatenates on every flow measurement branch, the precision of gas flow examination has been improved, and can realize the gas flowmeter's of the same bore or different bores batch detection calibration. In addition, the gas flowmeter calibrating device also comprises a filtering container assembly and a pressure stabilizing tank, so that the flow velocity fluctuation and the pressure fluctuation in the pipeline are reduced, and the calibrating precision can be further improved.
Fig. 1 shows a schematic structural diagram of a gas flowmeter calibrating apparatus according to a first embodiment of the present invention. As shown in fig. 1, the gas flowmeter calibrating device comprises a filtering container assembly, a surge tank 3, a confluence container 4, a flow control pipeline, a stagnation container 7 and a flow measurement pipeline which are connected in sequence; wherein the flow control pipeline comprises a plurality of flow control branches connected in parallel between the confluence container 4 and the stagnation container 7, and each flow control branch is provided with a first control valve 5 and a Venturi nozzle 6; the flow measurement pipeline comprises a plurality of flow measurement branches connected in parallel with the stagnation container 7, each flow measurement branch is provided with a standard gas flowmeter 9, and each flow measurement branch is used for being connected with a detected gas flowmeter 10.
Wherein, the filter container assembly comprises two filter containers 2 connected in series, and the number of the filter containers 2 can be more.
And a second control valve 8 is further arranged on each flow measurement branch, and the second control valve 8 is arranged between the stagnation container 7 and the standard gas flowmeter 9. The second control valve 8 can realize on-off control and flow control of each flow measurement branch, and the gas flowmeter calibrating device can simultaneously open any number of flow measurement branches during operation.
In this embodiment, the standard gas meter is a channel meter. The channel flowmeter is a differential pressure type flowmeter which is developed and produced by Nanjing Youyou control technology Limited and has independent intellectual property rights. The flowmeter is mainly characterized in that a streamline spindle body is used as a throttling element, so that the flow can be well regulated, the flow stability is kept, the flow separation is completely avoided, the measurement repeatability and the accuracy are improved, the pressure loss is remarkably reduced, the accuracy can reach 0.11 percent (a P.V.T.t. primary standard device of a gas flow measurement and detection center of Jiangsu province) to 0.2 percent (a P.V.T.t. primary standard device of a Chinese measurement scientific research institute), and the accuracy of a currently commonly used critical flow venturi nozzle is 0.25-0.3 percent. Of course, other types of standard gas flow meters may be used, which are not intended to limit the practice of the present invention.
According to the gas flowmeter calibrating device of the first embodiment, a standard gas flowmeter is arranged on each flow measurement branch in parallel, each flow measurement branch is connected with a to-be-detected gas flowmeter, the pipeline calibers of the flow measurement branches can be the same or different, the metering performance of the to-be-detected gas flowmeter is determined by comparing the readings of the standard gas flowmeter and the to-be-detected gas flowmeter, and batch detection and calibration of the gas flowmeters with the same calibers or different calibers are realized. The filtering container assembly comprises a plurality of filtering containers connected in series, flow velocity fluctuation in the pipeline can be reduced, the pressure stabilizing tank can reduce force fluctuation in the pipeline, and verification accuracy is improved.
Fig. 2 shows a schematic structural diagram of a gas flowmeter calibrating device according to a second embodiment of the present invention. As shown in fig. 2, the second embodiment differs from the first embodiment in that: the filter container assembly comprises a plurality of filter containers 2 connected in parallel. In the present embodiment, the number of filter containers 2 is two, but the number of filter containers 2 may be more.
Fig. 3 shows a schematic structural diagram of a gas flowmeter calibrating device according to a third embodiment of the present invention. As shown in fig. 3, the third embodiment differs from the first embodiment in that: the gas flow meter calibrating device further comprises a vacuum suction device 1, wherein the vacuum suction device 1 is connected to the filter container assembly and used for sucking air from the filter container assembly.
Considering economic investment and project income comprehensively, a negative pressure method is generally adopted at present, namely air is sucked from an open atmospheric space around a gas flow meter calibrating device to form air flow. When the detection calibration is performed, the second control valves 8 on all the selected flow measurement branches are opened while keeping all the first control valves 5 on the flow control lines in a closed state. Starting the vacuum suction device 1, pumping the air in the surge tank 3 and the confluence container 4 through the filtering container assembly, reducing the pressure at the downstream of the venturi nozzle 6 to a specific value, then opening the selected venturi nozzle 6 to combine with the corresponding first control valve 5, so that the air at the periphery of the inlet of the gas flowmeter verification device is sucked, and flows through the gas flowmeter 10 to be detected, the standard gas flowmeter 9, the second control valve 8, the stagnation container 7, the venturi nozzle 6, the first control valve 5, the confluence container 4, the surge tank 3, the filtering container assembly and the vacuum suction device 1 in sequence and is discharged to the atmosphere. And simultaneously collecting and reading readings of the standard gas flowmeter 9 and the detected gas flowmeter 10, and analyzing and comparing the two groups of data according to the related verification rules of the detected gas flowmeter 10 so as to determine the metering performances of the detected gas flowmeter 10, such as accuracy, repeatability and the like.
Fig. 4 shows a schematic structural diagram of a gas flowmeter calibrating device according to a fourth embodiment of the present invention. As shown in fig. 4, the fourth embodiment differs from the first embodiment in that: the gas flowmeter calibrating device also comprises a gas source 1, wherein the gas source 1 is connected with the filtering container assembly and is used for supplying gas to the filtering container assembly; each first control valve 5 is arranged between a venturi nozzle 6 and a stagnation container 7.
When the conditions permit, a positive pressure method can also be adopted, namely a certain gas source with enough pressure (such as a high-pressure gas pump, a gas storage tank, a pressurized gas conveying pipeline and the like) is connected to establish a gas flow verification system. When the detection calibration is performed, the second control valves 8 on all the selected flow measurement branches are opened while keeping all the first control valves 5 on the flow control lines in a closed state. And starting the gas source 12, enabling the gas to flow through the filtering container assembly, the pressure stabilizing tank 3 and the confluence container 4 until reaching the Venturi nozzle 6, and after the pressure rises to a specific value, opening the first control valve 5 corresponding to the selected Venturi nozzle 6 combination to enable the gas flow to pass through the Venturi nozzle 6 and to sequentially flow through the first control valve 5, the stagnation container 7, the second control valve 8, the standard gas flowmeter 9 and the detected gas flowmeter 10 to be discharged into the atmosphere. And simultaneously collecting and reading readings of the standard gas flowmeter 9 and the detected gas flowmeter 10, and analyzing and comparing the two groups of data according to the related verification rules of the detected gas flowmeter 10 so as to determine the metering performances of the detected gas flowmeter 10, such as accuracy, repeatability and the like.
Fig. 5 shows a schematic structural diagram of a gas flowmeter calibrating device according to a fifth embodiment of the present invention. As shown in fig. 5, the fifth embodiment is different from the fourth embodiment in that: the gas flowmeter calibrating device further comprises a recovery container 11, wherein the recovery container 11 is connected with each flow measuring branch respectively and is connected with the gas source 12 through a recovery gas pipeline. In the present embodiment, each of the gas meters to be detected 10 is provided between one of the standard gas meters 9 and the recovery tank 11.
When the testing gas is not discharged into the surrounding atmosphere, a circulating pipeline is constructed while a flow detection calibration system is established by adopting a positive pressure method, namely, the testing gas is collected and conveyed back to a gas source or a recovery device.
When the detection calibration is performed, the second control valves 8 on all the selected flow measurement branches are opened while keeping all the first control valves 5 on the flow control lines in a closed state. And starting the gas source 12 to enable the gas to flow through the filtering container assembly, the pressure stabilizing tank 3 and the confluence container 4 to the Venturi nozzle 6, after the pressure rises to a specific value, opening the first control valve 5 corresponding to the selected Venturi nozzle 6 combination, enabling the gas flow to pass through the Venturi nozzle 6, sequentially flow through the first control valve 5, the stagnation container 7, the second control valve 8, the standard gas flowmeter 9 and the detected gas flowmeter 10, discharge into the recovery container 11, and then convey back to the gas source 12, or can be processed additionally. And simultaneously collecting and reading readings of the standard gas flowmeter 9 and the detected gas flowmeter 10, and analyzing and comparing the two groups of data according to the related verification rules of the detected gas flowmeter 10 so as to determine the metering performances of the detected gas flowmeter 10, such as accuracy, repeatability and the like.
The foregoing description of the embodiments of the invention has been presented for purposes of illustration and not limitation, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the illustrated embodiments. The terms used herein were chosen in order to best explain the principles of the embodiments and the practical application, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
Claims (10)
1. A gas flowmeter calibrating device is characterized by comprising a filtering container assembly, a pressure stabilizing tank, a confluence container, a flow control pipeline, a stagnation container and a flow measurement pipeline which are sequentially connected; the flow control pipeline comprises a plurality of flow control branches connected between the confluence container and the stagnation container in parallel, and each flow control branch is provided with a first control valve and a Venturi nozzle; the flow measurement pipeline comprises a plurality of flow measurement branches connected in parallel with the stagnation container, a standard gas flowmeter is arranged on each flow measurement branch, and each flow measurement branch is used for being connected with a detected gas flowmeter.
2. The gas flow meter verification device of claim 1, wherein the filter vessel assembly comprises a plurality of filter vessels connected in series.
3. The gas flow meter verification device of claim 1, wherein the filter vessel assembly comprises a plurality of filter vessels connected in parallel.
4. The gas flow meter verification device according to claim 1, wherein a second control valve is further provided on each flow measurement branch, and the second control valve is provided between the stagnation container and the standard gas flow meter.
5. The gas flow meter verification device according to claim 1, further comprising a gas source connected to the filter vessel assembly for supplying gas to the filter vessel assembly.
6. The gas flow meter verification device according to claim 5, wherein each of the first control valves is disposed between one venturi nozzle and the stagnation vessel.
7. The gas flow meter verification device according to claim 6, further comprising a recovery tank connected to each flow measurement branch and connected to the gas source via a recovery gas line.
8. The gas flow meter verification device according to claim 7, wherein each of the gas flow meters to be verified is provided between one of the standard gas flow meters and the recovery tank.
9. The gas flow meter verification device according to claim 1, further comprising a vacuum suction device connected to the filter vessel assembly for evacuating air from the filter vessel assembly.
10. The gas flow meter verification device according to claim 9, wherein each of the first control valves is disposed between one venturi nozzle and the confluence vessel.
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| CN202020396576.5U CN210862863U (en) | 2020-03-25 | 2020-03-25 | Gas flowmeter calibrating device |
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| CN202020396576.5U CN210862863U (en) | 2020-03-25 | 2020-03-25 | Gas flowmeter calibrating device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113295243A (en) * | 2021-05-18 | 2021-08-24 | 安徽金大仪器有限公司 | Negative pressure type gas standard detection device based on sonic nozzle |
| CN113855982A (en) * | 2021-09-30 | 2021-12-31 | 深圳市科曼医疗设备有限公司 | Anesthetic evaporator |
-
2020
- 2020-03-25 CN CN202020396576.5U patent/CN210862863U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113295243A (en) * | 2021-05-18 | 2021-08-24 | 安徽金大仪器有限公司 | Negative pressure type gas standard detection device based on sonic nozzle |
| CN113855982A (en) * | 2021-09-30 | 2021-12-31 | 深圳市科曼医疗设备有限公司 | Anesthetic evaporator |
| CN113855982B (en) * | 2021-09-30 | 2023-07-18 | 深圳市科曼医疗设备有限公司 | Anesthesia evaporation device |
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