ONLINE MONITORING METHOD FOR METERING PERFORMANCE OF DIAPHRAGM GAS METER

Abstract

The present invention discloses an online method for metering performance of a diaphragm gas meter. A magnetic turntable in an electromechanical conversion device is reasonably segment and motion information of each segment is recorded and analyzed. Every time when the diaphragm gas meter discharges gas of a rotary volume, a rotating shaft of a meter core rotates a circle. The magnetic turntable is meshed with a driving gear output by the rotating shaft in the meter or output by the rotating shaft outside the meter to ensure that the magnetic turntable rotates a circle every time when the diaphragm gas meter discharges a rotary volume. The present invention is significant for error management of the gas meter and intelligent control and gas utilization safety management of a gas user.

Claims

1. An online monitoring method for metering performance of a diaphragm gas meter, which is characterized in that a magnetic turntable (53) in an electromechanical conversion device (5) is reasonably segmented and motion information of each segment is recorded and analyzed, so as to implement qualitative and quantitative judgment in metering errors of the diaphragm gas meter, internal leakage judgment, external leakage judgment and safety judgment for a constant flow rate.

2. The online monitoring method for the metering performance of the diaphragm gas meter according to claim 1, which is characterized in that the electromechanical conversion device (5) converts each rotary volume period to output more than two electrical pulse signals for metering accuracy judgment, constant flow rate judgment and safety prevention of external leakage hidden dangers of the meter.

3. The online monitoring method for the metering performance of the diaphragm gas meter according to claim 1, which is characterized in that the electromechanical conversion device (5) is selectively mounted in or outside the gas meter and comprises components such as a transmission gear (51), a bracket (52), the magnetic turntable (53), a magnetic switch Printed Circuit Board (PCB) (54) and magnets (55).

4. The online monitoring method for the metering performance of the diaphragm gas meter according to claim 1, which is characterized in that, no matter whether the electromechanical conversion device is mounted in or outside the meter, rotation of the magnetic turntable (53) for a circle corresponds to discharge of gas of a rotary volume by the gas meter, i.e., a discharge period; a plurality of symmetric circular grooves (531) are formed in a turntable plane of the magnetic turntable (53), and the magnets (55) may be embedded into the circular grooves (531); and a plurality of magnets (55) are arranged.

5. The online monitoring method for the metering performance of the diaphragm gas meter according to claim 1, which is characterized in that the electromechanical conversion device (5) is mounted outside a cavity of a gas meter housing (2), a metering bin (1) is arranged outside the gas meter, and a counter (11) and an outer driving gear (12) directly magnetically coupled to a diaphragm rotating shaft gear in a meter core (3) are arranged in the metering bin (1); the magnetic turntable (53) is embedded onto the outer driving gear (12) and rotates coaxially; the bracket (52) is fixedly mounted on the counter (11), and the magnetic switch PCB (54) is perpendicularly mounted on the bracket (52) and is parallel to the plane of the magnetic turntable (53); and the magnets (55) are arranged on the magnetic turntable (53), and a magnetic switch is welded on the magnetic switch PCB (54).

6. The online monitoring method for the metering performance of the diaphragm gas meter according to claim 1, which is characterized in that the electromechanical conversion device (5) is mounted in the cavity of the gas meter housing (2), the meter core (3) in the cavity of the gas meter is provided with a diaphragm rotating shaft (34), and the diaphragm rotating shaft gear is arranged on the diaphragm rotating shaft (34); and the transmission gear (51) is meshed with the diaphragm rotating shaft gear, the magnets (55) are arranged on the magnetic turntable (53), the magnetic switch is welded on the magnetic switch PCB (54), and the magnetic switch PCB (54) is perpendicularly mounted on the bracket (52) and is parallel to the plane of the magnetic turntable (53).

7. The online monitoring method for the metering performance of the diaphragm gas meter according to claim 1, which is characterized in that a proportion of rotating time consumption of each segment in a rotating period is analyzed to match properties of the specific meter, thereby implementing metering accuracy judgment and error management of the gas meter.

8. The online monitoring method for the metering performance of the diaphragm gas meter according to claim 1, which is characterized in that an electromechanical conversion component adopted in the electromechanical conversion device (5) may be the magnetic switch, a reed switch, a photoelectric direct-reading module, a touch switch and the like.

9. The online monitoring method for the metering performance of the diaphragm gas meter according to claim 1, which is characterized in that a maximum flow of the diaphragm gas meter (comprising a diaphragm meter) ranges from 0.016 to 160 m.sup.3/h.

10. The online monitoring method for the metering performance of the diaphragm gas meter according to claim 1, which is characterized in that setting gas consumption and gas utilization time for a constant flow rate to judge and prevent external leakage of the gas meter comprises the following steps: Step 1: for a relatively constant flow rate more than or equal to q3 m.sup.3/h and less than or equal to q1 m.sup.3/h, setting that one-time gas consumption is not allowed to exceed V1 m.sup.3; and reasonably setting values of q1, q3 and V1 according to a space volume of a relatively enclosed gas utilization region, gas utilization characteristics of gas equipment and an explosion lower limit (5%) of methane; Step 2: for a relatively constant flow rate higher than q1 m.sup.3/h and lower than the maximum flow of the gas meter, reasonably determining according to registration information of the gas equipment that the one-time gas consumption is not allowed to exceed V2 m.sup.3 and the duration is not allowed to exceed T.sub.1; and Step 3: for a flow between consequent generation of two period signals within 6 hours and q3 m.sup.3/h (minimum flow supporting the gas equipment), determining occurrence of leakage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is a mounting schematic diagram of an externally mounted electromechanical conversion device according to the present invention;

[0017] FIG. 2 is a structure diagram of an externally mounted electromechanical conversion device according to the present invention;

[0018] FIG. 3 is a mounting schematic diagram of an internally mounted electromechanical conversion device according to the present invention;

[0019] FIG. 4 is a structure diagram of an internally mounted electromechanical conversion device according to the present invention; and

[0020] FIG. 5 is a schematic diagram of coordinates when a circumference of a magnetic turntable is quartered according to the present invention.

[0021] In the figures: 1metering bin; 2meter housing; 3meter core; 5electromechanical conversion device; 11counter; 12outer driving gear; 34diaphragm rotating shaft; 36metering box; 51transmission gear; 52bracket; 53magnetic turntable; 54magnetic switch PCB; 55magnet; and 531circular groove.

DETAILED DESCRIPTION OF THE INVENTION

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the drawings in the embodiments of the present invention. It is apparent that the described embodiments are not all the embodiments but only part of embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art on the basis of the embodiments in the present invention without creative work shall fall within the scope of protection of the present invention.

[0023] Referring to FIG. 1-5, the embodiments of the present invention provide two technical solutions.

Embodiment 1

[0024] According to an online monitoring method for the metering performance of a diaphragm gas meter, an electromechanical conversion device 5 is mounted outside a cavity of a gas meter housing 2 (as shown in FIG. 1). A metering bin 1 is arranged outside the gas meter. A counter 11 and an outer driving gear 12 directly magnetically coupled to a diaphragm rotating shaft gear in a meter core 3 are arranged in the metering bin 1. A magnetic turntable 53 is embedded onto the outer driving gear 12 and rotates coaxially. A bracket 52 is fixedly mounted on the counter 11. A magnetic switch PCB 54 is perpendicularly mounted on the bracket 52 and is parallel to a plane of the magnetic turntable 53. Magnets 55 are arranged on the magnetic turntable 53. A magnetic switch is welded on the magnetic switch PCB 54.

[0025] The electromechanical conversion device 5 (as shown in FIG. 2) includes the bracket 52, the magnetic turntable 53, the magnetic switch PCB 54 and the magnets 55.

[0026] Rotation of the magnetic turntable 53 for a circle corresponds to discharge of gas of a rotary volume by the gas meter, i.e., a discharge period. A plurality of symmetric circular grooves 531 are formed in the turntable plane of the magnetic turntable 53 and the magnets 55 may be embedded into the circular grooves 531. The magnetic switch PCB 54 is embedded into the front end of the bracket 52 and is parallel to the plane of the magnetic turntable 53. When a magnet 55 rotates to be dead against the magnetic switch, the magnetic switch outputs a pulse signal. The number of pulse signals output by a metering box every time when a rotary volume is discharged is determined by the number of the magnets arranged on the magnetic turntable 53.

[0027] The magnetic turntable 53 in the electromechanical conversion device 5 is reasonably segmented and motion information of each segment is recorded and analyzed, so as to implement qualitative and quantitative judgment analysis such as judgment in metering performance reduction of the diaphragm gas meter and slight leakage judgment.

[0028] The electromechanical conversion device 5 converts each rotary volume period of the gas meter to output more than two electrical pulse signals for metering accuracy judgment, constant flow rate judgment and safety prevention of external leakage hidden dangers of the meter.

[0029] Rotation of the magnetic turntable 53 for a circle corresponds to discharge of gas of a rotary volume by the gas meter, i.e., the discharge period. The symmetric circular grooves 531 are formed in the turntable plane of the magnetic turntable 53 and the magnets 55 may be embedded into the circular grooves 531. When a magnet 55 rotates to be dead against the magnetic switch, the magnetic switch outputs a pulse signal. The number of the pulse signals output by the metering box every time when a rotary volume is discharged is determined by the number of the magnets arranged on the magnetic turntable 53.

[0030] The gas meter is a gas meter commonly used in life at present and will not be elaborated in the present application. The gas meter mainly includes components such as the metering bin 1, the meter housing 2 and the meter core 3. The meter core 3 is arranged in the gas meter. The meter core 3 mainly includes components such as a diaphragm rotating shaft 34 and the metering box 36.

Embodiment 2

[0031] According to an online monitoring method for the metering performance of a diaphragm gas meter, an electromechanical conversion device 5 is mounted in a cavity of a gas meter housing 2 (as shown in FIG. 3). A meter core 3 in the cavity of the gas meter is provided with a diaphragm rotating shaft 34 and a diaphragm rotating shaft gear is arranged on the diaphragm rotating shaft 34. A transmission gear 51 is meshed with the diaphragm rotating shaft gear. Magnets 55 are arranged on a magnetic turntable 53. A magnetic switch is welded on a magnetic switch PCB 54. The magnetic switch PCB 54 is perpendicularly mounted on a bracket 52 and is parallel to a plane of the magnetic turntable 53.

[0032] The electromechanical conversion device 5 (as shown in FIG. 4) includes the transmission gear 51, the bracket 52, the magnetic turntable 53, the magnetic switch PCB 54 and the magnets 55. Rotation of the magnetic turntable 53 for a circle corresponds to discharge of gas of a rotary volume by the gas meter, i.e., a discharge period. A plurality of symmetric circular grooves 531 are formed in the turntable plane of the magnetic turntable 53 and the magnets 55 may be embedded into the circular grooves 531. The magnetic switch PCB 54 is embedded into the front end of the bracket 52 and is parallel to the plane of the magnetic turntable 53. When a magnet 55 rotates to be dead against the magnetic switch, the magnetic switch outputs a pulse signal. The number of pulse signals output by a metering box every time when a rotary volume is discharged is determined by the number of the magnets arranged on the magnetic turntable 53.

[0033] The magnetic turntable 53 in the electromechanical conversion device 5 is reasonably segmented and motion information of each segment is recorded and analyzed, so as to implement qualitative and quantitative judgment analysis such as judgment in metering performance reduction of the diaphragm gas meter and slight leakage judgment. The electromechanical conversion device 5 converts each rotary volume period of the gas meter to output more than two electrical pulse signals for metering accuracy judgment, constant flow rate judgment and safety prevention of external leakage hidden dangers of the meter.

[0034] Qualitative analysis for online failure monitoring such as judgment in metering performance reduction of the diaphragm gas meter and internal leakage judgment is discussed in the present invention only with the condition that a circumference of the magnetic turntable is quartered as an example (as shown in FIG. 5). A time for rotation of the magnetic turntable for a circle is set to be T. Four magnets are assembled at symmetric positions where the circumference of the magnetic turntable is quartered. When the magnets pass through the magnetic switch, four time intervals t (t1, t2, t3 and t4) may be sampled and recorded. A ratio oft to the period T is set to be 1, 2, 3 and 4. In each rotary volume period, the diaphragm rotating shaft of the meter core of the gas meter rotates at an inconstant speed, so that the magnetic turntable of the electromechanical conversion device also rotates at an inconstant speed. Therefore, values of 1, 2, 3 and 4 are not all . In case of no leakage occurring to the gas meter, the values of 1, 2, 3 and 4 are fixed values or slightly fluctuate. In case of leakage or failure occurring to the gas meter, if leakage is distributed not according to an original proportion coefficient when a gas flow is stable (multiple fixed periods are measured), offsets will inevitably exist for the values of the 1, 2, 3 and 4, and when the offsets reach a certain value, it may be qualitatively judged that internal leakage occurs to the gas meter.

[0035] During practical use, in case of leakage occurring to the gas meter, the time interval is generally shorter than of a rotary volume period. In of the period when leakage occurs, the value of at least one of t1, t2, t3 and t4 may not be affected by leakage or is slightly affected. If it is measured that time intervals at which the four magnets pass through the magnetic switch are t1, t2, t3 and t4 in case of leakage occurring to the gas meter, 1, 2, 3 and 4 may be calculated, and are compared with 1, 2, 3 and 4 in case of no leakage occurring to the gas meter to find the one with maximum decrease (set to be 4, i.e., the time interval minimally affected by leakage), and the normal discharge period T=t4/4 of each rotary volume of the gas meter may be calculated. It is practically measured that the discharge period of each rotary volume of the gas meter is T=(t1+t2+t3+t4). Accordingly, a period deviation T=TT may be obtained. Then, a ratio of T to T is a leakage proportion coefficient of the gas meter. When leakage or another metering performance failure occurs to the gas meter, gas loss of a gas company may be calculated through the proportion coefficient.

[0036] If quantitative calculation for a leakage condition when the time interval is longer than of the period is required, it is only necessary to uniquely increase the number of the magnets on the magnetic turntable. In addition, another magnetic switch forming a certain angular relationship with the original magnetic switch may be additionally arranged for reference to the original measured parameter.

[0037] The electromechanical conversion device provided by the present invention is required to output more than two electrical pulse signals in each period, and such high-density signals may be used for metering a micro flow below the minimum flow. For a household diaphragm gas meter of which a maximum flow is smaller than 6 m.sup.3/h, an electromechanical conversion device outputting two electrical pulse signals in a period is adopted. In the present invention, gas consumption and gas utilization time are set for a constant flow rate to judge and prevent external leakage of the gas meter through the following flow.

[0038] In Step 1, for a relatively constant flow rate more than or equal to q3 m.sup.3/h and less than or equal to q1 m.sup.3/h, one-time gas consumption is not allowed to exceed V1 m.sup.3; and values of q1, q3 and V1 are reasonably set according to a space volume of a relatively enclosed gas utilization region, gas utilization characteristics of gas equipment and an explosion lower limit (5%) of methane.

[0039] In Step 2, for a relatively constant flow rate higher than q1 m.sup.3/h and lower than the maximum flow of the gas meter, it is reasonably determined according to registration information of the gas equipment that the one-time gas consumption is not allowed to exceed V2 m.sup.3 and the duration is not allowed to exceed T.sub.1.

[0040] In Step 3, for a flow between consequent generation of two period signals within 6 hours and q3 m.sup.3/h (minimum flow supporting the gas equipment), occurrence of leakage is determined.

[0041] The electromechanical conversion device adapted to the present invention is required to output more than two electrical pulse signals in each period, and such a signal density is used for accurate, rapid and reliable constant flow rate judgment and judgment in slight leakage below a starting flow.

[0042] From the above, the present invention is significant for metering performance monitoring and local meter detection of the diaphragm gas meter and also for intelligent monitoring and gas utilization safety management of the meter.

[0043] It is to be noted that relationship terms such as first and second in the present invention are adopted not always to require or imply existence of any such practical relationship or sequence between entities or operations but only to distinguish one entity or operation from another entity or operation. moreover, terms include and contain or any other variant thereof is intended to cover nonexclusive inclusions, thereby ensuring that a process, method, object or equipment including a series of elements not only includes those elements but also includes other elements which are not clearly listed or further includes elements intrinsic to the process, the method, the object or the equipment without more restrictions.

[0044] Although the embodiments of the present invention have been illustrated and described, those of ordinary skill in the art may know that various variations, modifications, replacements and transformations may be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and equivalents thereof.