A volume corrector supporting disassembly-free calibration accumulated error

Abstract

The application discloses a volume correction instrument supporting disassembly-free calibration accumulated error, and relates to the technical field of volume correction instruments, aiming to solve the technical problem that the existing calibration scheme needs to destroy the sealing and explosion-proof structure of equipment, and comprises a data processing module and an operation module. The application directly leads to the structure of the pressure digital bus through the calibration aviation interface temperature, discards the calibration mode of the prior art of disassembling the shell and manually wiring inside, and only needs to be connected with the calibration aviation interface on the correction instrument shell through a special cable, so that the transmission of the analog temperature and pressure bus protocol signal can be realized, and the original explosion-proof sealing structure of the correction instrument does not need to be destroyed throughout the process. The application effectively prevents the risk of gas leakage caused by the failure of sealing, and prevents safety accidents such as explosion and poisoning from occurring, and is especially suitable for personnel-intensive gas metering sites such as residential areas and commercial complexes. The application solves the problem that the existing calibration scheme needs to destroy the sealing and explosion-proof structure of equipment.

Description

Technical Field

[0001] This invention relates to the field of volume corrector technology, and more specifically, to a volume corrector that supports non-disassembly calibration of integration errors. Background Technology

[0002] An intelligent volumetric corrector is a secondary instrument for gas flow meters, equipped with a flow sensor, a digital temperature sensor, and a digital pressure sensor. Upon receiving pulse flow, temperature, and pressure signals from the base meter, it uses a mathematical model to calculate the volumetric flow rate under operating and standard conditions. It also displays, stores, and transmits data such as temperature, pressure, and flow rate. Gas flow meters with volumetric correctors are commonly used in trade metering within the urban gas industry. Due to the flammable and explosive nature of natural gas, the safety requirements for the instrument are very high. These are nationally approved and mandatory verification measuring instruments, requiring periodic verification and calibration to ensure long-term accuracy.

[0003] Due to the flammable and explosive properties of natural gas, volume correctors fall under the category of measuring instruments requiring national type approval and mandatory verification. They must undergo regular verification and calibration to ensure long-term measurement accuracy. Existing calibration methods require disrupting the equipment's sealing and explosion-proof structure, posing serious safety hazards. To achieve signal interaction during calibration, technicians must first remove the seal, then disassemble the corrector's casing, exposing the internal circuit board and terminals for manual wiring. This operation directly compromises the corrector's original explosion-proof sealing design. Since gas metering sites are often densely populated areas such as residential communities and commercial complexes, improper subsequent assembly after the equipment's seal is compromised can easily lead to gas leaks, causing explosions, poisoning, and other safety accidents. Furthermore, the unsealing and disassembly process may damage internal sensors or circuits, negatively impacting the corrector's measurement accuracy, creating a contradiction between calibration and damage. Therefore, we propose a volume corrector that supports disassembly-free calibration of integration errors. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art, adapt to practical needs, and provide a volume correction instrument that supports non-disassembly calibration and integration error, so as to solve the technical problem that the current calibration scheme requires the destruction of the equipment's sealing and explosion-proof structure.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a volume corrector that supports non-disassembly calibration of integrated errors, comprising a data processing module and an operation module. The data processing module includes an integration unit and a receiving unit, used to integrate volumetric flow rate values ​​under operating and standard conditions using a mathematical model. The operation module includes operation buttons and a calibration aviation interface, which are disposed on the housing of the volume corrector and directly connected to the integration unit. The calibration aviation interface is configured to be able to directly connect to an external calibration and testing experimental device to receive analog temperature and pressure bus protocol signals, thereby achieving non-disassembly calibration.

[0006] Preferably, the data processing module is configured to: receive simulated temperature and pressure signals from the calibration aviation interface, calculate the deviation between the corrector compensation coefficient and the theoretical value, and complete the calibration verification without disassembling the casing, wherein the compensation coefficient deviation calculation algorithm is based on the formula:

[0007]

[0008] in, This is the compensation coefficient for the corrector. The deviation rate;

[0009] Judgment criteria: When When the calibration is successful and meets the mandatory verification standards, When the value is greater than 0.5%, the display unit triggers a calibration error message.

[0010] Preferably, the calibration aviation interface adopts the form of an aviation plug, directly leading out the temperature and pressure digital bus, which meets the IP67 protection level. The operation button is located on the housing of the volume corrector and is connected to the data processing module for controlling the start and stop of the calibration process.

[0011] Preferably, it also includes a signal acquisition module, comprising a digital temperature sensor, a digital pressure sensor, and a flow sensor, used to acquire pulse signals from the flow meter base and ambient temperature and pressure signals. The acquired pulse frequency is used to calculate the operating volumetric flow rate. The formula is: =Pulse frequency × Single pulse volume.

[0012] Preferably, the digital temperature sensor and digital pressure sensor in the signal acquisition module use I²C or SPI digital bus protocol for data transmission.

[0013] Preferably, it also includes a data storage module connected to the data processing module for storing and displaying temperature, pressure, and flow data.

[0014] Preferably, it further includes a data transmission module, which includes an antenna interface. The data transmission module is connected to the data storage module. The antenna interface is disposed on the housing of the volume corrector and connected to the data transmission module. The antenna interface is configured to connect to an external antenna to enhance the wireless data transmission capability.

[0015] Preferably, the mathematical model uses the AGA-8 standard gas state equation for volumetric flow rate integration;

[0016] The volumetric flow rate totalization algorithm is based on the formula:

[0017]

[0018] in: This is the standard volumetric flow rate. This refers to the volumetric flow rate under operating conditions. This is the actual gas pressure. Atmospheric pressure This refers to the actual temperature of the gas. Standard temperature, The compressibility factor of the gas under operating conditions. This is the gas compression factor under standard conditions.

[0019] Preferably, it also includes a safety protection module, which adopts an explosion-proof design and meets the safety requirements of flammable and explosive gas environments.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. This invention directly extracts the pressure digital bus from the calibration aviation interface temperature, eliminating the need for disassembling the casing and manually wiring internally, as required by existing technologies. The external calibration and testing device only needs to connect to the calibration aviation interface on the corrector casing via a dedicated cable to achieve the transmission of analog temperature and pressure bus protocol signals, without damaging the original explosion-proof sealing structure of the corrector. This effectively eliminates the risk of gas leakage due to sealing failure, thereby preventing safety accidents such as explosions and poisoning, and is particularly suitable for gas metering sites with high population density, such as residential communities and commercial complexes. It solves the problem that existing calibration schemes require damage to the equipment's sealing and explosion-proof structure.

[0022] 2. This invention also clarifies the criteria for determining whether calibration is qualified by calculating the deviation rate δ between the actual compensation coefficient K and the theoretical compensation coefficient of the corrector, rather than relying on the subjective judgment of existing technologies. This quantitative judgment method avoids errors in the manual comparison process, making the calibration results more objective and accurate. At the same time, the deviation rate data can be recorded through the data storage module, providing a basis for subsequent traceability of the calibration process and analysis of the accuracy change trend of the corrector, further improving the rigor and reliability of the calibration work. Attached Figure Description

[0023] Figure 1 This is a schematic block diagram of the system structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the external structure of the present invention;

[0025] Figure 3 This is a schematic diagram of the structure of the present invention.

[0026] The labels in the diagram are as follows: 1. Antenna interface; 2. Operation button; 3. Calibration aviation interface; 4. Digital temperature sensor; 5. Digital pressure sensor; 6. Flow sensor. Detailed Implementation

[0027] Example: Figures 1 to 3 As shown, the present invention relates to a volume corrector that supports non-disassembly calibration and integration error calculation, comprising a data processing module and an operation module. The data processing module includes an integration unit and a receiving unit, used to integrate volumetric flow rate values ​​under operating and standard conditions using a mathematical model. The data processing module is configured to receive simulated temperature and pressure signals from a calibration aviation interface 3, calculate the deviation between the corrector's compensation coefficient and the theoretical value, and complete calibration verification without disassembling the housing. The operation module includes an operation button 2 and a calibration aviation interface 3, which are located on the housing of the volume corrector and directly connected to the integration unit. The calibration aviation interface 3 adopts an aviation plug form, directly leading out a temperature and pressure digital bus, and meets the IP67 protection level. The operation button 2 is located on the housing of the volume corrector and connected to the data processing module, used to control the start and stop of the calibration process. The calibration aviation interface 3 is configured to be able to directly connect to an external calibration and testing experimental device, receive simulated temperature and pressure bus protocol signals, and realize non-disassembly calibration.

[0028] The data processing module uses the STM32L476VET6 industrial-grade MCU as the main control chip, and implements flow totalization and calibration deviation analysis through two core algorithms:

[0029] The mathematical model uses the AGA-8 standard gas state equation to calculate the volumetric flow rate.

[0030] The document takes into account the hardware computing power of the corrector and the relatively stable composition of the gas at the site. It adopts the optimized AGA-8, which only requires inputting the 21 components required by AGA-8. The AGA-8 compressibility factor corresponding to the temperature and pressure points is pre-calculated, as shown in the table below. The actual value is fitted using the lookup table method and the linear correction method.

[0031]

[0032] Standard condition volumetric flow rate correction formula: The core function of the intelligent volumetric flow rate corrector is to adjust the standard condition volumetric flow rate. Convert to standard volumetric flow rate (Standard conditions: temperature) =20℃, pressure The formula is:

[0033]

[0034] in, The volumetric flow rate (m³ / h) is calculated from the pulse frequency collected by flow sensor 6. =Pulse frequency × Single pulse volume; The actual gas pressure (kPa) is the value collected by a digital pressure sensor. Atmospheric pressure (kPa, default 101.325kPa, can be calibrated via operation button); The actual gas temperature (°C) is the value collected by a digital temperature sensor. Standard temperature; The gas compressibility factor under operating conditions (calculated according to the AGA-8 formula, input) , (It can be obtained from 21 components). This is the gas compressibility factor under standard conditions (calculated by inputting the temperature, pressure, and 21 components under standard conditions).

[0035] Compensation coefficient deviation calculation algorithm: The core of calibration is to verify the compensation coefficient of the corrector. With theoretical compensation coefficient To ensure consistency, this embodiment quantifies the deviation using a formula, avoiding subjective human judgment. The formula is:

[0036] Definition of compensation coefficient:

[0037] Compensation coefficient The formula for calculating the corrector's ability to correct for "temperature and pressure effects" is as follows:

[0038]

[0039] For the correction instrument based on the collected data , The calculated standard flow rate (obtained from the above integration formula) The theoretical standard flow rate output by the external calibration and testing experimental device;

[0040] Deviation rate calculation:

[0041] To intuitively determine whether the calibration is qualified, a deviation rate is defined. :

[0042]

[0043] Judgment criteria: When When the calibration is successful, it meets the mandatory verification standards; when If the error rate is greater than 0.5%, the display unit will trigger a calibration error message, requiring investigation of the sensor or integration model.

[0044] The aviation connector uses the GX16-2 type 2-pin anti-misinsertion aviation connector, with the following specific design: The two pins of the aviation interface are connected to the temperature and pressure digital bus (I²C's SDA and SCL lines) respectively, and are directly electrically connected to the I²C interface of the data processing module without the need for an intermediate conversion circuit; the interface shell is made of stainless steel, and the sealing ring is made of nitrile rubber, which meets the IP67 protection level and is suitable for the humid and dusty environment of the gas field. When the external calibration and testing experimental device is inserted into the aviation interface through a dedicated cable, it can transmit the analog temperature and pressure bus signal without disassembling the corrector shell.

[0045] Preferably, it also includes a signal acquisition module, comprising a digital temperature sensor 4, a digital pressure sensor 5, and a flow sensor 6, for acquiring pulse signals from the flow meter base and ambient temperature and pressure signals. The digital temperature sensor 4 and digital pressure sensor 5 in the signal acquisition module use I²C or SPI digital bus protocols for data transmission.

[0046] Preferably, it also includes a data storage module connected to the data processing module for storing and displaying temperature, pressure, and flow data.

[0047] Preferably, it also includes a data transmission module, which includes an antenna interface 1. The data transmission module is connected to the data storage module. The antenna interface 1 is disposed on the housing of the volume corrector and connected to the data transmission module. The antenna interface 1 is configured to connect to an external antenna to enhance the wireless data transmission capability.

[0048] Antenna interface 1 is an SMA type threaded interface, with the following functions:

[0049] Data Upload: Historical data is uploaded to the remote monitoring platform once every hour, and the deviation rate is reported in real time when calibration anomalies occur. ;

[0050] Command reception: Receives parameter configuration commands, such as standard temperature, issued by the remote platform. Modified, the transmission protocol is now LoRaWAN.

[0051] Preferably, it also includes a safety protection module, which adopts an explosion-proof design and meets the safety requirements of flammable and explosive gas environments.

[0052] The embodiments disclosed in this invention are preferred embodiments, but are not limited thereto. Those skilled in the art can easily understand the spirit of this invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of this invention, they are all within the protection scope of this invention.

Claims

1. A volumetric corrector supporting tear down free calibration accumulated error, characterized in that, The volume correction instrument comprises a data processing module and an operation module. The data processing module comprises a calculation unit and a receiving unit, which are used for calculating the volume flow value under the working condition and the standard condition by using a mathematical model. The operation module comprises operation buttons and a calibration aviation interface, which are arranged on the volume correction instrument shell and are directly connected with the calculation unit. The calibration aviation interface is configured to be directly connected with an external calibration detection experiment device to receive an analog temperature and pressure bus protocol signal and realize the calibration without disassembly.

2. A volumetric corrector supporting a tear-free calibration of accumulated errors according to claim 1, characterized in that, The data processing module is configured to: receive the analog temperature and pressure signal from the calibration aviation interface; calculate the deviation of the compensation coefficient of the volume correction instrument from the theoretical value; complete the calibration verification without disassembly of the shell; The compensation coefficient deviation calculation algorithm is based on the formula: wherein, is a correction factor for the instrument, is a bias rate; Decision criteria: when the calibration is qualified, which meets the mandatory verification standard, when > 0.5%, the display unit triggers a calibration anomaly prompt.

3. A volumetric corrector supporting a tear-free calibration of accumulated errors according to claim 2, characterized in that, The calibration aviation interface adopts an aviation plug form to directly lead out a temperature and pressure digital bus and meets the IP67 protection level. The operation buttons are arranged on the volume correction instrument shell and are connected with the data processing module to control the start and stop of the calibration process.

4. The volumetric corrector of claim 1, wherein, Also include signal acquisition module, including digital temperature sensor, digital pressure sensor and flow sensor, for collecting flow meter base table pulse signal and environmental temperature and pressure signal, the pulse frequency collected is used for calculating working condition volume flow , the formula is: = pulse frequency x single pulse volume.

5. A volumetric corrector supporting a tear-free calibration of accumulated errors according to claim 4, characterized in that, The digital temperature sensor and the digital pressure sensor in the signal acquisition module adopt I2C or SPI digital bus protocol for data transmission.

6. The volumetric corrector of claim 1, wherein, The volume correction instrument further comprises a data storage module connected with the data processing module, which is used for storing and displaying the temperature, pressure and flow data.

7. A volumetric corrector supporting a tear-free calibration of accumulated errors according to claim 6, characterized in that, The volume correction instrument further comprises a data transmission module, which comprises an antenna interface. The antenna interface is arranged on the volume correction instrument shell and is connected with the data transmission module. The antenna interface is configured to be connected with an external antenna to enhance the wireless data transmission capability.

8. The volumetric corrector supporting demountable calibration accumulated error according to claim 4, characterized in that, The mathematical model adopts the AGA-8 standard gas state equation for volume flow calculation. The volume flow calculation algorithm is based on the formula: wherein: is the standard volume flow rate, is the working volume flow rate, is the actual pressure of the fuel gas, is the atmospheric pressure, is the actual temperature of the fuel gas, is the standard temperature, is the fuel gas compression factor at working conditions, is the fuel gas compression factor at standard conditions.

9. The volumetric corrector of claim 1, wherein, The volume correction instrument further comprises a safety protection module, which adopts an explosion-proof design and meets the safety requirements of the flammable and explosive gas environment.

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