阅读说明：本技术 天然气超声波流量计的在线原位校准方法及装置 (Online in-situ calibration method and device for natural gas ultrasonic flowmeter ) 是由 武大志 伍海峰 何丹丹 于 2020-06-19 设计创作，主要内容包括：本发明公开了一种天然气超声波流量计的在线原位校准方法及装置,涉及计量校准技术领域,解决了目前固定管道天然气超声波计量计都需要分离拆卸进行校准,无法实现现场原位校准的问题。本发明的主要技术方案为：安装标准超声波流量计,将标准超声波流量计安装至待测超声波流量计的相邻位置；根据所述标准超声波流量计的示值校准所述待测超声波流量计的示值误差、测量重复性和测量稳定性；其中,所述标准超声波流量计和待测超声波流量计位于管道的同一直线管段上。本发明主要用于天然气超声波流量计的校准。(The invention discloses an online in-situ calibration method and device for a natural gas ultrasonic flowmeter, relates to the technical field of metering calibration, and solves the problem that the conventional fixed pipeline natural gas ultrasonic flowmeter needs to be detached for calibration and cannot realize on-site in-situ calibration. The main technical scheme of the invention is as follows: installing a standard ultrasonic flowmeter, and installing the standard ultrasonic flowmeter to the adjacent position of the ultrasonic flowmeter to be measured; calibrating the indicating value error, the measurement repeatability and the measurement stability of the ultrasonic flowmeter to be measured according to the indicating value of the standard ultrasonic flowmeter; the standard ultrasonic flowmeter and the ultrasonic flowmeter to be measured are positioned on the same straight pipe section of the pipeline. The method is mainly used for calibrating the natural gas ultrasonic flowmeter.)

1. An online in-situ calibration method for a natural gas ultrasonic flowmeter is characterized by comprising the following steps:

installing a standard ultrasonic flowmeter, and installing the standard ultrasonic flowmeter to the adjacent position of the ultrasonic flowmeter to be measured;

calibrating the indicating value error, the measurement repeatability and the measurement stability of the ultrasonic flowmeter to be measured according to the indicating value of the standard ultrasonic flowmeter;

the standard ultrasonic flowmeter and the ultrasonic flowmeter to be measured are positioned on the same straight pipe section of the pipeline.

2. The method of on-line in-situ calibration of an ultrasonic natural gas flow meter according to claim 1,

the calibration of the indicating value error of the ultrasonic flowmeter to be measured according to the indicating value of the standard ultrasonic flowmeter is specifically as follows:

acquiring an accumulated flow indicating value of the standard ultrasonic flowmeter within a first preset time, calculating an indicating value error of the ultrasonic flowmeter to be measured according to a formula (1) through the accumulated flow indicating value of the ultrasonic flowmeter to be measured,

ΔV＝V_i-V₀(1)

wherein Δ V is an indication error of the accumulated flow of the ultrasonic flowmeter to be measured in a first preset time, L or m³；

V_iAn indication value of the accumulated flow of the ultrasonic flowmeter to be measured in a first preset time, L or m³；

V₀An indication of the cumulative flow rate, L or m, of the standard ultrasonic flowmeter over a first predetermined time³。

3. The on-line in-situ calibration of a natural gas ultrasonic flow meter according to claim 1,

the measurement repeatability for calibrating the ultrasonic flowmeter to be measured according to the indicating value of the standard ultrasonic flowmeter is specifically as follows:

reading the accumulated flow indicating value of the standard ultrasonic flowmeter at least n times every second preset time interval, and calculating the arithmetic mean value as a first standard value;

reading the accumulated flow indicating value of the ultrasonic flowmeter to be measured at least n times every second preset time interval, and calculating the arithmetic mean value of the accumulated flow indicating value as a first measuring value;

and calculating the measurement repeatability of the ultrasonic flowmeter to be measured according to the first standard value and the first measured value.

4. The method of on-line in-situ calibration of an ultrasonic natural gas flow meter according to claim 3,

the calculating the measurement repeatability of the ultrasonic flowmeter to be measured according to the first standard value and the first measurement value specifically comprises:

calculating the difference value between the first measurement value and the first standard value, if the difference value is less than or equal to the maximum allowable error of the ultrasonic flowmeter to be measured, calculating the repeatability of the ultrasonic flowmeter to be measured according to a formula (2), and if the difference value is greater than the maximum allowable error of the ultrasonic flowmeter to be measured, calculating the measurement repeatability of the ultrasonic flowmeter to be measured according to a formula (3),

wherein S is_nThe measurement repeatability of the ultrasonic flowmeter to be measured is obtained;

V_ithe value of the cumulative flow for the ith measurement of the ultrasonic flowmeter to be measured, L or m³；

V_i0Is the first measured value, L or m, of the ultrasonic flow meter under test³；

V₀Is the first standard value, L or m, of the standard ultrasonic flow meter³。

5. The method of on-line in-situ calibration of an ultrasonic natural gas flow meter according to claim 3,

n has a value of 10.

6. The method of on-line in-situ calibration of an ultrasonic natural gas flow meter according to claim 1,

the calibration of the measurement stability of the ultrasonic flowmeter to be measured according to the indicating value of the standard ultrasonic flowmeter is specifically as follows:

reading the accumulated flow indication value of the standard ultrasonic flowmeter at least s times every second preset time interval, and calculating the arithmetic mean value as a second standard value;

reading the accumulated flow indication value of the ultrasonic flowmeter to be measured at least s times every second preset time interval, testing one group at every preset number of days, testing at least m groups, and calculating the arithmetic mean value as a second measurement value;

and calculating the measurement stability of the ultrasonic flowmeter to be measured according to the second standard value and the second measured value.

7. The method of on-line in-situ calibration of an ultrasonic natural gas flow meter according to claim 6,

the step of calculating the measurement stability of the ultrasonic flowmeter to be measured according to the second standard value and the second measured value specifically includes:

calculating the difference value between the second measurement value and the second standard value, if the difference value is less than or equal to the maximum allowable error of the ultrasonic flowmeter to be measured, calculating the measurement stability of the ultrasonic flowmeter to be measured according to a formula (4), and if the difference value is greater than the maximum allowable error of the ultrasonic flowmeter to be measured, calculating the measurement stability of the ultrasonic flowmeter to be measured according to a formula (5),

wherein S is_mThe measurement repeatability of the ultrasonic flowmeter to be measured is obtained;

is the arithmetic mean value of the m-th measurement accumulated flow of the ultrasonic flowmeter to be measured, L or m³；

Is the arithmetic mean value, L or m, of the second measured value of the ultrasonic flowmeter to be measured³；

Is the arithmetic mean, L or m, of said second standard value of said standard ultrasonic flow meter³。

8. The method of on-line in-situ calibration of an ultrasonic natural gas flow meter according to claim 6,

s has a value of 10 and m has a value of 4.

9. An on-line in-situ calibration device for a natural gas ultrasonic flowmeter, which is applied to the on-line in-situ calibration method for the natural gas ultrasonic flowmeter as claimed in any one of claims 1 to 8, and is characterized by comprising the following steps:

the ultrasonic flowmeter to be measured and the standard ultrasonic flowmeter are arranged on the same straight line pipe section of the pipeline;

the standard ultrasonic flowmeter is an external clamp type ultrasonic flowmeter.

10. The in-situ calibration device for a natural gas ultrasonic flowmeter according to claim 9,

the distance between the ultrasonic flowmeter to be measured and the standard ultrasonic flowmeter is 10-20 cm.

Technical Field

The invention relates to the technical field of measurement calibration, in particular to an online in-situ calibration method and device for a natural gas ultrasonic flowmeter.

Background

The metering of natural gas flow is an extremely important part in the natural gas pipeline industry, and the accuracy of the measured data directly influences the economic benefit of a production enterprise and the benefit of a user. In recent years, many users have started to use a fixed multi-channel ultrasonic flowmeter as a natural gas meter in a large number, the ultrasonic flowmeter measures the flow rate of natural gas by using a propagation time difference method, the propagation time difference method ultrasonic flowmeter works by using ultrasonic transducers to alternately (or simultaneously) transmit and receive ultrasonic pulses in opposite directions, indirectly measure the flow rate of fluid by detecting and calculating the propagation time difference between forward flow and backward flow of a medium, and then calculate the flow rate by using the flow rate. However, the existing fixed pipeline natural gas ultrasonic wave metering meter needs to be detached and disassembled for calibration.

Disclosure of Invention

In view of this, the embodiment of the invention provides an online in-situ calibration method and device for a natural gas ultrasonic flowmeter, and mainly aims to solve the problem that the existing fixed pipeline natural gas ultrasonic meter needs to be detached for calibration and cannot be calibrated in situ on site. In order to achieve the purpose, the invention mainly provides the following technical scheme:

in one aspect, an embodiment of the present invention provides an online in-situ calibration method for a natural gas ultrasonic flowmeter, where the calibration method for a natural gas flowmeter includes: installing a standard ultrasonic flowmeter, and installing the standard ultrasonic flowmeter to the adjacent position of the ultrasonic flowmeter to be measured;

calibrating the indicating value error, the measurement repeatability and the measurement stability of the ultrasonic flowmeter to be measured according to the indicating value of the standard ultrasonic flowmeter;

the standard ultrasonic flowmeter and the ultrasonic flowmeter to be measured are positioned on the same straight pipe section of the pipeline.

Optionally, calibrating the indication error of the to-be-measured ultrasonic flowmeter according to the indication of the standard ultrasonic flowmeter specifically includes:

acquiring an accumulated flow indicating value of the standard ultrasonic flowmeter within a first preset time, calculating an indicating value error of the ultrasonic flowmeter to be measured according to a formula (1) through the accumulated flow indicating value of the ultrasonic flowmeter to be measured,

ΔV＝V_i-V₀(1)

wherein Δ V is an indication error of the accumulated flow of the ultrasonic flowmeter to be measured in a first preset time, L or m³；

V_iAn indication value of the accumulated flow of the ultrasonic flowmeter to be measured in a first preset time, L or m³；

V₀An indication of the cumulative flow rate, L or m, of the standard ultrasonic flowmeter over a first predetermined time³。

Optionally, calibrating the measurement repeatability of the ultrasonic flowmeter to be measured according to the indication value of the standard ultrasonic flowmeter specifically includes:

reading the accumulated flow indicating value of the standard ultrasonic flowmeter at least n times every second preset time interval, and calculating the arithmetic mean value as a first standard value;

reading the accumulated flow indicating value of the ultrasonic flowmeter to be measured at least n times every second preset time interval, and calculating the arithmetic mean value of the accumulated flow indicating value as a first measuring value;

and calculating the measurement repeatability of the ultrasonic flowmeter to be measured according to the first standard value and the first measured value.

Optionally, the calculating the measurement repeatability of the ultrasonic flowmeter to be measured according to the first standard value and the first measurement value specifically includes:

calculating the difference value between the first measurement value and the first standard value, if the difference value is less than or equal to the maximum allowable error of the ultrasonic flowmeter to be measured, calculating the repeatability of the ultrasonic flowmeter to be measured according to a formula (2), and if the difference value is greater than the maximum allowable error of the ultrasonic flowmeter to be measured, calculating the measurement repeatability of the ultrasonic flowmeter to be measured according to a formula (3),

wherein S is_nThe measurement repeatability of the ultrasonic flowmeter to be measured is obtained;

V_ithe value of the cumulative flow for the ith measurement of the ultrasonic flowmeter to be measured, L or m³；

V_i0Is the first measured value, L or m, of the ultrasonic flow meter under test³；

V₀Is the first standard value, L or m, of the standard ultrasonic flow meter³。

Optionally, the value of n is 10.

Optionally, calibrating the measurement stability of the to-be-measured ultrasonic flowmeter according to the indication value of the standard ultrasonic flowmeter specifically includes:

reading the accumulated flow indication value of the standard ultrasonic flowmeter at least s times every second preset time interval, and calculating the arithmetic mean value as a second standard value;

reading the accumulated flow indication value of the ultrasonic flowmeter to be measured at least s times every second preset time interval, testing one group at every preset number of days, testing at least m groups, and calculating the arithmetic mean value as a second measurement value;

and calculating the measurement stability of the ultrasonic flowmeter to be measured according to the second standard value and the second measured value.

Optionally, the calculating the measurement stability of the ultrasonic flowmeter to be measured according to the second standard value and the second measured value specifically includes:

calculating the difference value between the second measurement value and the second standard value, if the difference value is less than or equal to the maximum allowable error of the ultrasonic flowmeter to be measured, calculating the measurement stability of the ultrasonic flowmeter to be measured according to a formula (4), and if the difference value is greater than the maximum allowable error of the ultrasonic flowmeter to be measured, calculating the measurement stability of the ultrasonic flowmeter to be measured according to a formula (5),

wherein S is_mThe measurement repeatability of the ultrasonic flowmeter to be measured is obtained;

is the arithmetic mean value of the m-th measurement accumulated flow of the ultrasonic flowmeter to be measured, L or m³；

Is the arithmetic mean value, L or m, of the second measured value of the ultrasonic flowmeter to be measured³；

Is the arithmetic mean, L or m, of said second standard value of said standard ultrasonic flow meter³。

Optionally, s is 10, and m is 4.

In another aspect, an embodiment of the present invention provides an online in-situ calibration device for a natural gas ultrasonic flowmeter, where the online in-situ calibration device for a natural gas ultrasonic flowmeter includes: the ultrasonic flowmeter to be measured and the standard ultrasonic flowmeter are arranged on the same straight line pipe section of the pipeline;

the standard ultrasonic flowmeter is an external clamp type ultrasonic flowmeter.

Optionally, the distance between the ultrasonic flowmeter to be measured and the standard ultrasonic flowmeter is 10-20 cm.

The on-line in-situ calibration method and the device for the natural gas ultrasonic flowmeter, which are provided by the embodiment of the invention, aim at the calibration of the ultrasonic flowmeter to be measured of a fixed pipeline, the calibration method provided by the embodiment is to install the calibrated standard ultrasonic flowmeter as the standard flowmeter to carry out synchronous measurement, the standard ultrasonic flowmeter is calibrated, a worker already masters the uncertainty and the accumulated flow correction value in the measurement range, the standard ultrasonic flowmeter is installed at the adjacent position of the ultrasonic flowmeter to be measured and ensures that the standard ultrasonic flowmeter and the ultrasonic flowmeter to be measured are positioned on the same straight pipe section of the same pipeline, and the indication error, the measurement repeatability and the measurement stability of the ultrasonic flowmeter to be measured can be calibrated according to the indication value of the standard ultrasonic flowmeter based on the principle that the accumulated flow numbers of the standard ultrasonic flowmeter and the ultrasonic flowmeter to be measured are, the ultrasonic flowmeter to be measured can be calibrated in situ without separation and disassembly operations.

Drawings

Fig. 1 is a schematic flow chart of an online in-situ calibration method for a natural gas ultrasonic flowmeter according to an embodiment of the present invention;

fig. 2 is another schematic flow chart of an online in-situ calibration method for a natural gas ultrasonic flowmeter according to an embodiment of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description will be given to the method and apparatus for on-line in-situ calibration of a natural gas ultrasonic flowmeter according to the present invention, and the specific implementation, structure, features and effects thereof, with reference to the accompanying drawings and preferred embodiments.