阅读说明：本技术 一种钟罩式气体流量检定装置及方法 (Bell-type gas flow calibrating device and method ) 是由 刘达生 施峰 于 2021-09-07 设计创作，主要内容包括：本发明涉及气体流量检定技术领域,公开了一种钟罩式气体流量检定装置及方法,装置包括钟罩检定单元、钟罩行程采集模块、信号转换模块和控制系统,钟罩检定单元包括钟罩,钟罩检定单元与待检气体流量计连接,钟罩行程采集模块设置在钟罩处,用于采集钟罩的行程信息；信号转换模块与钟罩行程采集模块连接,用于将钟罩的行程信息转换为电信号；信号转换模块与控制系统电信号连接,控制系统将信号转换模块输出的电信号转化为钟罩过气体积随时间变化数据,并根据钟罩过气体积随时间变化数据拟合得到变化曲线。本发明无需人工读取秒表和基表数据,减少人为误差,提高测试结果的准确性,且降低工作强度,提高工作效率。(The invention relates to the technical field of gas flow verification, and discloses a bell-jar type gas flow verification device and a method thereof, wherein the device comprises a bell-jar verification unit, a bell-jar stroke acquisition module, a signal conversion module and a control system, the bell-jar verification unit comprises a bell jar, the bell-jar verification unit is connected with a gas flowmeter to be detected, and the bell-jar stroke acquisition module is arranged at the bell jar and is used for acquiring stroke information of the bell jar; the signal conversion module is connected with the bell-jar stroke acquisition module and is used for converting stroke information of the bell jar into an electric signal; the signal conversion module is in electrical signal connection with the control system, the control system converts the electrical signal output by the signal conversion module into bell gas passing volume data changing along with time, and a change curve is obtained according to the bell gas passing volume data changing along with time in a fitting mode. According to the invention, the data of the second table and the base table do not need to be read manually, so that the human error is reduced, the accuracy of the test result is improved, the working intensity is reduced, and the working efficiency is improved.)

1. A bell-jar type gas flow calibrating device is characterized by comprising a bell-jar calibrating unit, a bell-jar stroke acquisition module, a signal conversion module and a control system, wherein the bell-jar calibrating unit comprises a bell jar, the bell-jar calibrating unit is connected with a gas flowmeter to be detected, and the bell-jar stroke acquisition module is arranged at the bell jar and used for acquiring stroke information of the bell jar; the signal conversion module is connected with the bell jar stroke acquisition module and is used for converting the stroke information of the bell jar into an electric signal; the signal conversion module is in electrical signal connection with the control system, the control system converts the electrical signal output by the signal conversion module into bell gas volume data changing with time, and a change curve is obtained by fitting according to the bell gas volume data changing with time.

2. The bell jar gas flow verification apparatus of claim 1, further comprising a display module electrically coupled to the control system for displaying a bell jar gas flow volume versus time graph.

3. The bell jar gas flow verification device as claimed in claim 2, wherein the bell jar gas flow verification device comprises a table on which the gas flow meter to be tested, the control system, and the display module are mounted.

4. The bell jar gas flow verification device according to claim 1, wherein the gas flow meter to be detected is a diaphragm gas meter.

5. The bell jar gas flow verification device of claim 1, wherein the signal conversion module is a photoelectric encoder.

6. A method of calibrating a bell jar gas flow calibration apparatus according to any one of claims 1 to 5, comprising:

acquiring stroke information of the downward movement of the bell jar by using a bell jar stroke acquisition module;

converting the stroke information of the bell jar into an electric pulse signal;

converting the electric pulse signal into data of the change of the bell gas volume along with time;

fitting according to the data of the bell gas passing volume changing along with time to obtain a bell gas passing volume changing along with time curve;

and calculating to obtain the parameter information of the gas flowmeter to be detected according to the curve of the bell gas volume changing with time.

7. The verification method as claimed in claim 6, wherein the formula for calculating the parameter information of the gas flowmeter to be detected according to the change curve of the bell jar gas volume with time is as follows:

wherein Q represents the instantaneous flow rate, v (t) represents the bell gas passing volume at time t, and t represents time.

8. The verification method as claimed in claim 6, wherein the formula for calculating the parameter information of the gas flowmeter to be detected according to the change curve of the bell jar gas volume with time is as follows:

wherein Q is_iRepresents the average flow per pulse, L₀Denotes the equivalent pulse volume, T_iRepresents unit pulse time, and i represents the number of pulses.

9. The assay method as claimed in claim 6, further comprising displaying a bell jar gas volume versus time graph using a display module.

Technical Field

The invention relates to the technical field of gas flow verification, in particular to a bell-type gas flow verification device and a bell-type gas flow verification method.

Background

The bell-jar gas flow standard device is standard equipment for detecting the diaphragm gas meter by taking air as a medium, and consists of two parts, namely a bell-jar gas flow standard device and a detection workbench. The principle is that the effective volume in the bell jar is used as the standard volume, and when the bell jar descends, gas in the bell jar flows through the detected gas meter through the connecting pipeline. And taking the volume of the bell jar converted from the descending height of the bell jar as a standard volume, and comparing the standard volume with the volume indicated by the gas meter to be detected to obtain the basic error of the gas meter to be detected. Before indication error detection of membrane gas meters with different specifications is generally carried out, the volume required by each flow point in 1 minute needs to be calculated, and meanwhile, with popularization and use of an internet of things intelligent gas meter with a safety monitoring function, the average flow of the membrane gas meter in a unit pulse period needs to be tested.

At present, a stopwatch is used for measuring time, and the average flow is manually calculated after the rotating volume of a counting wheel of a base meter is read. However, manually reading the data of the second table and the base table not only increases the working strength, but also generates artificial errors, thereby reducing the accuracy of the test result; in addition, because the instantaneous flow displayed on the verification workbench fluctuates due to the influence of hardware equipment factors in the test process, the accuracy of the test result is influenced when the instantaneous flow displayed on the verification workbench is used for calculating the average flow in the unit pulse of the gas meter.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a bell-type gas flow verification apparatus and a method thereof, so as to solve the problems of the existing bell-type gas flow verification apparatus, such as high working strength and low accuracy of test results.

In order to achieve the purpose, the invention adopts the following technical scheme:

one aspect of the invention provides a bell-jar type gas flow calibrating device, which comprises a bell-jar calibrating unit, a bell-jar stroke acquisition module, a signal conversion module and a control system, wherein the bell-jar calibrating unit comprises a bell jar, the bell-jar calibrating unit is connected with a gas flowmeter to be detected, and the bell-jar stroke acquisition module is arranged at the bell jar and is used for acquiring stroke information of the bell jar; the signal conversion module is connected with the bell jar stroke acquisition module and is used for converting the stroke information of the bell jar into an electric signal; the signal conversion module is in electrical signal connection with the control system, the control system converts the electrical signal output by the signal conversion module into bell gas volume data changing with time, and a change curve is obtained by fitting according to the bell gas volume data changing with time.

Preferably, the bell-type gas flow verification device further comprises a display module, wherein the display module is electrically connected with the control system and is used for displaying a bell-type gas passing volume curve graph along with time.

Preferably, the bell-type gas flow calibrating device comprises a workbench, and the gas flowmeter to be detected, the control system and the display module are all mounted on the workbench.

Preferably, the gas flowmeter to be detected is a membrane gas meter.

Preferably, the signal conversion module is a photoelectric encoder.

Another aspect of the present invention provides a method of calibrating a bell jar gas flow calibration apparatus as described above, comprising:

acquiring stroke information of the downward movement of the bell jar by using a bell jar stroke acquisition module;

converting the stroke information of the bell jar into an electric pulse signal;

converting the electric pulse signal into data of the change of the bell gas volume along with time;

fitting according to the data of the bell gas passing volume changing along with time to obtain a bell gas passing volume changing along with time curve;

and calculating to obtain the parameter information of the gas flowmeter to be detected according to the curve of the bell gas volume changing with time.

Preferably, the formula for calculating the parameter information of the gas flowmeter to be detected according to the change curve of the bell gas volume with time is as follows:

wherein Q represents the instantaneous flow rate, v (t) represents the bell gas passing volume at time t, and t represents time.

Preferably, the formula for calculating the parameter information of the gas flowmeter to be detected according to the change curve of the bell gas volume with time is as follows:

wherein Q is_iRepresents the average flow per pulse, L₀Denotes the equivalent pulse volume, T_iRepresents unit pulse time, and i represents the number of pulses.

Preferably, the verification method further comprises displaying a bell jar gas volume versus time graph using the display module.

Compared with the prior art, the bell-type gas flow calibrating device and method provided by the embodiment of the invention have the beneficial effects that:

according to the bell-jar type gas flow calibrating device provided by the embodiment of the invention, the bell-jar stroke collecting module is arranged at the bell jar to collect the stroke information of the bell jar, and the change curve of the bell-jar gas passing volume along with time is obtained according to the stroke information of the bell jar, so that the instantaneous flow and the average flow in unit pulse of the gas flowmeter to be detected can be directly obtained by using the change curve, the data of a second table and a base table do not need to be read manually, the human error is reduced, the accuracy of a test result is improved, the working intensity is reduced, and the working efficiency is improved. And the change curve can be used for directly acquiring detection and calibration time so as to facilitate preparation work of metering personnel. In addition, the invention utilizes the fitted curve of the change of the air passing volume along with the time to calculate the average flow in the unit pulse, thereby reducing the influence caused by the instantaneous flow fluctuation and further improving the accuracy of the test result.

Drawings

FIG. 1 is a block diagram of a bell jar gas flow verification apparatus according to an embodiment of the present invention; a

Fig. 2 is a schematic flow chart of a calibration method of a bell jar gas flow calibration apparatus according to an embodiment of the present invention;

FIG. 3 is a graph of bell gas volume as a function of time for an embodiment of the present invention.

In the figure, 1, a bell jar verification unit; 2. a bell jar stroke acquisition module; 3. a signal conversion module; 4. a control system; 5. and a display module.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

As shown in fig. 1, a bell jar type gas flow verification apparatus according to a preferred embodiment of the present invention includes a bell jar verification unit 1, a bell jar stroke acquisition module 2, a signal conversion module 3, and a control system 4, where the bell jar verification unit 1 includes a bell jar, the bell jar verification unit 1 is connected to a gas flow meter to be detected, the gas flow meter to be detected may be a membrane gas meter, when the bell jar moves downward, gas in the bell jar flows through the gas flow meter to be detected through a connection pipeline, and a basic error of the gas flow meter to be detected may be obtained by comparing a gas passing volume of the bell jar with a volume indicated by the gas flow meter to be detected, where the gas passing volume of the bell jar refers to a gas volume entering the gas flow meter to be detected from the bell jar. The bell jar stroke acquisition module 2 is arranged at the bell jar and is used for acquiring stroke information of the bell jar, wherein the stroke information refers to a downward movement stroke of the bell jar; the signal conversion module 3 is connected with the bell jar stroke acquisition module 2, and is used for converting stroke information of the bell jar into an electric signal which can be identified by the control system 4 and transmitting the electric signal to the control system 4, wherein the signal conversion module 3 is a photoelectric encoder; the signal conversion module 3 is in electrical signal connection with the control system 4, the control system 4 converts the electrical signal output by the signal conversion module 3 into bell-jar gas passing volume data changing with time, and fits the bell-jar gas passing volume data changing with time to obtain a change curve, wherein the bell-jar gas passing volume data changing with time refers to data pairs of gas passing volume values and time in one-to-one correspondence, the change curve is a change curve obtained by fitting a plurality of groups of data pairs, and the bell-jar gas passing volume value can be obtained by combining the inner diameter of a bell jar according to the stroke information of the bell jar as the inner diameter of the bell jar is known. The parameter information of the gas flowmeter to be detected can be directly obtained according to the change curve of the bell gas volume along with the time, the parameter information comprises the instantaneous flow at any moment and the average flow in unit pulse, and the measurement error of the gas flowmeter to be detected can be obtained by comparing the instantaneous flow obtained by the change curve with the indicated flow of the gas flowmeter to be detected.

Further, the bell-type gas flow verification device further comprises a display module 5, wherein the display module 5 is electrically connected with the control system 4 and is used for displaying a bell-type gas passing volume curve with time so as to visually display the change trend of the bell-type gas passing volume with time and directly read the instantaneous flow from the curve.

In the invention, a bell jar calibrating unit 1 comprises a bell jar, a bell jar sliding seat, a water tank and a frame, wherein the bell jar is covered in water in the water tank, the bell jar is connected with a gas flowmeter to be detected through a connecting pipeline, the top of the bell jar is arranged on the bell jar sliding seat, the bell jar sliding seat is slidably arranged on the frame, and when the bell jar moves under the water surface along the frame, gas in the bell jar enters the gas flowmeter to be detected through the connecting pipeline under the extrusion action of the water. The bell jar is a container with an opening at one side, the opening of the bell jar is arranged downwards, when the bell jar is covered in the water tank, the water surface forms a liquid seal for the bell jar, and a closed cavity is formed inside the bell jar. The bell jar is also connected with an air duct and a blower, the blower is connected with the air duct, and the bell jar is inflated by the blower so as to move upwards. The bell jar verification unit further comprises a pressure adjusting device, and specifically comprises a hanging rope, a fixed pulley and a balance weight, wherein one end of the hanging rope is connected with the bell jar sliding seat, and the other end of the hanging rope is connected with the balance weight by bypassing the fixed pulley so as to adjust the pressure in the bell jar. Furthermore, the bell jar calibration unit further comprises a bell jar pressure compensation device and a liquid level compensation device, both the bell jar pressure compensation device and the liquid level compensation device are in the prior art, and detailed description is omitted in the present invention.

The gas flowmeter to be detected can be multiple, the gas flowmeters to be detected are arranged in parallel, and the gas flowmeters to be detected are all connected with the bell jar verification unit 1.

The bell-jar type gas flow calibrating device comprises a workbench, wherein the gas flowmeter to be detected, the control system 4 and the display module 5 are all arranged on the workbench. Further, a key part is arranged on the workbench and connected with the control system 4 and the display module 5 so as to input detection time, the serial number of the gas flowmeter to be detected and the like.

As shown in fig. 2, the calibration method of the bell-type gas flow calibration apparatus according to the present invention includes the following steps:

step S1, acquiring the stroke information of the downward movement of the bell jar by using a bell jar stroke acquisition module 2, wherein the bell jar stroke acquisition module 2 is arranged at the bell jar, and the stroke information refers to the downward movement stroke of the bell jar;

step S2, converting the stroke information of the bell jar into an electric pulse signal that can be recognized by the control system 4;

step S3, converting the electric pulse signal into data of the change of the bell gas volume along with time, wherein the data are a plurality of groups of data pairs of the bell gas volume and the time which are in one-to-one correspondence;

step S4, fitting the time-varying data of the bell jar gas passing volume to obtain a bell jar gas passing volume time-varying curve, as shown in FIG. 3;

and step S5, calculating parameter information of the gas flowmeter to be detected according to the change curve of the bell jar gas volume along with time, wherein the parameter information comprises test time, instantaneous flow and average flow in unit pulse. Transient flow and average flow can be directly obtained through the bell jar gas volume curve of changing along with time, and through this transient flow with wait to examine the flow of examining gas flowmeter's instruction, can obtain the measuring error who waits to examine gas flowmeter, and need not the manual work and read stopwatch and base table data, reduce artificial error, improve the accuracy of test result, and reduce working strength, improve work efficiency.

In step S5, the formula of the instantaneous flow rate calculated according to the time-dependent change curve of the bell jar gas passing volume is:

wherein Q represents the instantaneous flow rate, v (t) represents the bell gas passing volume at time t, and t represents time.

In step S5, the formula for obtaining the average flow rate in the unit pulse by calculation according to the time-dependent change curve of the bell jar gas passing volume is:

wherein Q is_iRepresenting the average flow per pulse, L₀Denotes the equivalent pulse volume, T_iRepresents unit pulse time, and i represents the number of pulses.

Wherein L is₀＝L_i-L_i-1，T_i＝t_i-t_i-1In the formula, L_iIndicating the bell gas volume, L, at the time of the ith pulse_i－1Represents the bell gas passing volume, t, at the time of the i-1 th pulse_iDenotes the time, t, of the ith pulse_i－1Indicating the time instant at the i-1 th pulse.

Further, the verification method further comprises the step of displaying a curve graph of the change of the bell gas passing volume along with time by using the display module 5 so as to visually display the trend of the change of the bell gas passing volume along with time and to facilitate the direct reading of the instantaneous flow from the curve graph.

It should be noted that other embodiments of the calibration method of the bell-type gas flow calibration apparatus according to the present invention are substantially the same as those of the bell-type gas flow calibration apparatus described above, and will not be described herein again.

In summary, the embodiment of the invention provides a bell-jar type gas flow calibrating device and method, wherein a bell-jar stroke acquisition module 2 is arranged at a bell jar to acquire stroke information of the bell jar, and a curve of change of a bell-jar gas passing volume along with time is obtained according to the stroke information of the bell jar, so that instantaneous flow and average flow in unit pulse of a gas flowmeter to be tested can be directly obtained by using the change curve, manual reading of data of a second meter and a base meter is not needed, human errors are reduced, the accuracy of a test result is improved, the working strength is reduced, and the working efficiency is improved. And the change curve can be used for directly acquiring detection and calibration time so as to facilitate preparation work of metering personnel. In addition, the invention utilizes the fitted curve of the change of the air passing volume along with the time to calculate the average flow in the unit pulse, thereby reducing the influence caused by the instantaneous flow fluctuation and further improving the accuracy of the test result.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.