Calibration system for low-temperature fluid flowmeter

Abstract

The invention discloses a low-temperature liquid flowmeter calibration system, relates to the technical field of calibration, and aims to solve the problem of low efficiency and accuracy when a flowmeter is calibrated. The low-temperature fluid flowmeter calibration system comprises a control device, a first acquisition device, a standard meter, a second acquisition device and a temperature transmitter. And the standard meter is connected in series with the flowmeter to be calibrated and the fluid equipment during working. The fluid equipment is equipment for fluid flowing or flowing out in the actual working scene of the to-be-calibrated flowmeter. The first collection device is used for collecting first flow information measured by the flowmeter to be calibrated. And the second acquisition equipment is used for acquiring second flow information measured by the standard meter. The temperature transmitter is used for measuring the temperature of fluid flowing through the standard meter. The control equipment is used for controlling the working states of the first acquisition equipment and the second acquisition equipment according to the fluid temperature. The control device is further used for determining an error value corresponding to the flowmeter to be calibrated according to the first flow information and the second flow information.

Description

Technical Field

[0001] The present application relates to the field of calibration technology, and in particular to a cryogenic liquid flow meter calibration system. Background Art

[0002] In fluid production and transportation scenarios such as tank trucks or factories, flow meters that measure the mass flow of fluids are usually installed. In order to ensure that the flow meter has stable accuracy, the flow meter needs to be calibrated. The relevant method usually adopts the method of removing the flow meter from the production and transportation scene and sending it to a relevant laboratory for calibration. This method is not only time-consuming, but the calibration medium used in the laboratory may not be consistent with the medium actually used on site, which may cause large errors in the calibration results and low accuracy. Summary of the invention

[0003] The purpose of the present application is to provide a cryogenic liquid flow meter calibration system, aiming to solve the problem of low efficiency and accuracy when calibrating the flow meter.

[0004] In order to achieve the above purpose, this application adopts the following technical solutions:

[0005] In the first aspect, an embodiment of the present application provides a cryogenic liquid flow meter calibration system, comprising: a control device, a first acquisition device, a standard table, a second acquisition device, and a temperature transmitter. The control device is connected to the first acquisition device, the second acquisition device, and the temperature transmitter respectively. When the standard table is working, it is connected in series with the flow meter to be calibrated and the fluid device. The fluid device is a device for the flow direction or outflow of the fluid in the actual working scene of the flow meter to be calibrated. The first acquisition device is used to collect the first flow information measured by the flow meter to be calibrated. The second acquisition device is used to collect the second flow information measured by the standard table. The temperature transmitter is used to measure the temperature of the fluid flowing through the standard table. The control device is used to control the working state of the first acquisition device and the second acquisition device according to the fluid temperature. The control device is also used to determine the error value corresponding to the flow meter to be calibrated based on the first flow information and the second flow information.

[0006] Based on this, the present application can support the calibration of the flow meter to be calibrated in the actual working scenario of the flow meter to be calibrated, avoiding the time-consuming disassembly and calibration of the flow meter to be calibrated, and the problem that the calibration medium used in the laboratory may be inconsistent with the medium actually used on site, resulting in large errors in the calibration results. This makes the calibration data more consistent with the actual working conditions of the flow meter to be calibrated, thereby improving the accuracy of the calibration.

[0007] In some embodiments, the flow meter to be calibrated has a display module for displaying the accumulated mass flow measured by the flow to be calibrated. The first acquisition device is a camera device for acquiring image information of the display module. The control device is also used to obtain the first flow information from the image information.

[0008] In some embodiments, the first acquisition device is a frequency counter for acquiring the number of pulses measured by the flow meter to be calibrated. The control device is also used to determine the first flow information corresponding to the flow meter to be calibrated according to the number of pulses and the pulse coefficient of the flow meter to be calibrated.

[0009] In some embodiments, the second acquisition device is a frequency counter for acquiring the number of pulses measured by the standard meter. The control device is also used to determine the second flow information corresponding to the standard meter according to the number of pulses and the pulse coefficient of the standard meter.

[0010] In some embodiments, the system further comprises: a pressure transmitter. The pressure transmitter is used to measure the fluid pressure. The control device is also used to adjust the second flow information of the standard meter according to the fluid temperature and the fluid pressure.

[0011] In some embodiments, quick-release connectors are provided at both ends of the standard meter, and are respectively connected to the flow meter to be calibrated and the fluid equipment through the quick-release connectors.

[0012] In some embodiments, the system further comprises: a vent valve. The vent valve is arranged in the fluid pipeline at the output end of the standard meter.

[0013] In some embodiments, the system further comprises: a safety valve. The safety valve is arranged in the fluid pipeline at the input end of the standard meter.

[0014] In some embodiments, the fluid comprises a liquid having a boiling point below -153°C at normal pressure.

[0015] In some embodiments, the control device is further used to control the working state of the first collection device and the second collection device to be turned on in multiple preset flow intervals. The multiple preset flow intervals include: 20%Q~50%Q, 50%Q~100%Q, and Q is the maximum mass flow during calibration.

[0016] In the second aspect, an embodiment of the present application provides a cryogenic liquid flow meter calibration method, which is applied to a control device in a cryogenic liquid flow meter calibration system. The cryogenic liquid flow meter calibration system also includes: a first acquisition device, a standard meter, a second acquisition device, and a temperature transmitter. The control device is connected to the first acquisition device and the second acquisition device, respectively. When the standard meter is working, it is connected in series with the flow meter to be calibrated and the fluid device. The fluid device is a device for the flow direction or outflow of the fluid in the actual working scene of the flow meter to be calibrated. The first acquisition device is used to collect the first flow information measured by the flow meter to be calibrated. The second acquisition device is used to collect the second flow information measured by the standard meter. The temperature transmitter is used to measure the temperature of the fluid flowing through the standard meter.

[0017] The cryogenic liquid flow meter calibration method includes: obtaining multiple groups of cumulative mass flow rates when the second flow information and the fluid temperature meet the calibration conditions. The calibration conditions are used to limit the mass flow point where the second flow information is located when the calibration starts, and the temperature range where the fluid temperature is located when the calibration starts. A group of cumulative mass flow rates includes a first flow information and a second flow information measured in the same acquisition period. Different groups of cumulative mass flow rates correspond to different mass flow points. According to the multiple groups of cumulative mass flow rates, the error value corresponding to each mass flow point of the flow meter to be calibrated is determined for calibration of the flow meter to be calibrated.

[0018] Based on this, the present application can support the calibration of the flowmeter to be calibrated in the actual working scenario of the flowmeter to be calibrated, avoiding the time-consuming disassembly and calibration of the flowmeter to be calibrated, and the calibration medium used in the laboratory may be inconsistent with the medium actually used on site, resulting in large errors in the calibration results. In this way, the control device can obtain multiple sets of cumulative mass flow rates when the second flow information and the fluid temperature meet the calibration conditions, so that the calibration data is more in line with the actual working conditions of the flowmeter to be calibrated, and the accuracy of the calibration is improved.

[0019] Furthermore, considering that the flow meter to be calibrated may have different measurement errors at different mass flow points, the present application can support the collection of multiple groups of cumulative mass flow rates at different mass flow points, and then determine the error values ​​corresponding to the flow meter to be calibrated at different mass flow points, so as to accurately calibrate the flow meter to be calibrated.

[0020] In some embodiments, the method for obtaining multiple groups of cumulative mass flow rates specifically includes: determining a starting mass flow rate based on a starting image, and determining a termination mass flow rate based on a termination image. The starting image is an image captured by the first acquisition device at the beginning of a collection period. The termination image is an image captured by the first acquisition device at the end of a collection period. The difference between the termination mass flow rate and the starting mass flow rate is determined as the first flow information.

[0021] In some embodiments, the method for obtaining multiple groups of cumulative mass flow rates specifically includes: dividing the standard meter pulse number by the standard meter pulse coefficient to determine the second flow rate information. The standard meter pulse number is the number of pulses measured by the standard meter collected by the second collection device within a collection period.

[0022] In some embodiments, the method further comprises: adjusting the second flow information according to the fluid temperature and the fluid pressure. The fluid pressure is the pressure when the fluid flows through the standard meter.

[0023] In some embodiments, a method for determining the error value corresponding to each mass flow point of the flow meter to be calibrated based on multiple groups of cumulative mass flow rates specifically includes: determining the ratio of the difference between the second flow information and the first flow information in a group of cumulative mass flow rates to the first flow information in the same group of cumulative mass flow rates as the error value corresponding to a group of cumulative mass flow rates, and obtaining the error value corresponding to each mass flow point of the flow meter to be calibrated.

[0024] In some embodiments, the fluid comprises a liquid having a boiling point below -153°C at normal pressure.

[0025] In the third aspect, an embodiment of the present application provides a cryogenic liquid flow meter calibration device, which is applied to a control device in a cryogenic liquid flow meter calibration system. The cryogenic liquid flow meter calibration system also includes: a first acquisition device, a standard meter, a second acquisition device, and a temperature transmitter. The control device is connected to the first acquisition device and the second acquisition device, respectively. When the standard meter is working, it is connected in series with the flow meter to be calibrated and the fluid device. The fluid device is a device for the flow direction or outflow of the fluid in the actual working scene of the flow meter to be calibrated. The first acquisition device is used to collect the first flow information measured by the flow meter to be calibrated. The second acquisition device is used to collect the second flow information measured by the standard meter. The temperature transmitter is used to measure the temperature of the fluid flowing through the standard meter.

[0026] The cryogenic liquid flow meter calibration device includes: an acquisition unit and a processing unit. The acquisition unit is used to acquire multiple groups of cumulative mass flow rates when the second flow information and the fluid temperature meet the calibration conditions. The calibration conditions are used to limit the mass flow point where the second flow information is located when the calibration starts, and the temperature range where the fluid temperature is located when the calibration starts. A group of cumulative mass flow rates includes a first flow information and a second flow information measured in the same acquisition period. Different groups of cumulative mass flow rates correspond to different mass flow points.

[0027] The processing unit is used to determine the error value corresponding to each mass flow point of the flow meter to be calibrated according to multiple groups of accumulated mass flow rates, so as to calibrate the flow meter to be calibrated.

[0028] In some embodiments, the acquisition unit is specifically used to: determine the starting mass flow rate based on the starting image, and determine the ending mass flow rate based on the ending image. The starting image is an image acquired by the first acquisition device at the beginning of a collection period. The ending image is an image acquired by the first acquisition device at the end of a collection period. The difference between the ending mass flow rate and the starting mass flow rate is determined as the first flow information.

[0029] In some embodiments, the acquisition unit is specifically configured to: determine the quotient of the standard meter pulse number divided by the standard meter pulse coefficient as the second flow information. The standard meter pulse number is the pulse number measured by the standard meter collected by the second collection device within a collection period.

[0030] In some embodiments, the processing unit is further used to adjust the second flow information according to the fluid temperature and the fluid pressure. The fluid pressure is the pressure when the fluid flows through the standard meter.

[0031] In some embodiments, the processing unit is specifically used to: determine the difference between the second flow information and the first flow information in a group of cumulative mass flow, and the ratio of the difference between the second flow information and the first flow information in the same group of cumulative mass flow as an error value corresponding to a group of cumulative mass flow, and obtain the error value corresponding to each mass flow point of the flow meter to be calibrated.

[0032] In some embodiments, the fluid comprises a liquid having a boiling point below -153°C at normal pressure.

[0033] In a fourth aspect, an embodiment of the present application provides a computer device, comprising: a processor, the processor is connected to a memory, the memory is used to store computer execution instructions, the processor executes the computer execution instructions stored in the memory, so that the computer device performs a low-temperature liquid flow meter calibration method such as any one of the second aspects.

[0034] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium for storing computer execution instructions. When the computer execution instructions are executed on a computer device, the computer device executes a cryogenic liquid flow meter calibration method as described in any one of the second aspects.

[0035] In a sixth aspect, an embodiment of the present application provides a computer program product, comprising computer execution instructions, which, when executed on a computer device, enable the computer device to execute a cryogenic liquid flow meter calibration method as described in any one of the second aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 A schematic diagram of the structure of a cryogenic liquid flow meter calibration system provided in an embodiment of the present application;

[0038] Figure 2 A schematic diagram of the structure of another cryogenic liquid flow meter calibration system provided in an embodiment of the present application;

[0039] Figure 3 A schematic diagram of the structure of a control device provided in an embodiment of the present application;

[0040] Figure 4 A schematic flow chart of a cryogenic liquid flow meter calibration method provided in an embodiment of the present application;

[0041] Figure 5 A schematic structural diagram of a cryogenic liquid flow meter calibration device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "inside", "outside", etc. indicate directions or positional relationships based on the directions or relative positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on this application. Unless otherwise specified, the above-mentioned directional description can be flexibly set in the process of actual application under the condition that the relative positional relationship shown in the accompanying drawings is met.

[0044] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0045] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. It can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] In the present application, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, article or device including the element.

[0047] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0048] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0049] First, a brief introduction to the application scenarios involved in this application is given.

[0050] In fluid production and transportation scenarios such as tank trucks or factories, flow meters for measuring fluid mass flow are usually installed. In order for the flow meter to have stable accuracy, the flow meter needs to be calibrated. The relevant method usually adopts the method of disassembling the flow meter from the production and transportation scenario and sending it to the relevant laboratory for calibration. This disassembly and calibration method is not only time-consuming, but the calibration medium used in the laboratory may not be consistent with the medium actually used on site, which may cause large errors in the calibration results and low accuracy. At the same time, it is easy to affect the production and transportation of the fluid, resulting in high calibration costs.

[0051] In addition, this disassembly calibration method can only obtain the basic error of the flow meter, and it is difficult to know the additional error in the fluid production and transportation scenario. For example, for tank trucks that need to transport cryogenic liquids, this calibration method easily ignores the error caused by the difference between the liquid temperature during tank truck filling and unloading and the temperature of the laboratory calibration liquid, and cannot meet the needs of calibrating cryogenic liquid metering flow meters for tank truck filling and unloading.

[0052] Next, the implementation environment (implementation architecture) involved in this application is briefly introduced.

[0053] like Figure 1, which is a schematic diagram of the structure of a cryogenic liquid flow meter calibration system provided in an embodiment of the present application. The cryogenic liquid flow meter calibration system may include a control device 101, a standard meter 102, a first acquisition device 103, a second acquisition device 104, and a temperature transmitter 105. The control device 101 is connected to the first acquisition device 103, the second acquisition device 104, and the temperature transmitter 105, respectively.

[0054] When working, the standard meter 102 is connected in series with the flow meter to be calibrated 106 and the fluid device 107. The standard meter 102 can be a DN50 high-precision mass flow meter.

[0055] Optionally, the fluid device 107 is a device for the flow direction or outflow of the fluid in the actual working scene of the flow meter 106 to be calibrated. For example, the fluid device 107 can be a storage tank for the flow direction of the fluid. For another example, the fluid device 107 can be a liquid source for the fluid to flow out. The fluid can include a liquid with a boiling point lower than -153° C. at normal pressure.

[0056] The first acquisition device 103 is used to acquire the first flow information measured by the flow meter 106 to be calibrated. For example, when the flow meter 106 to be calibrated is provided with a display module and the measured cumulative mass flow can be displayed through the display module, the first acquisition device 103 may be a camera device for acquiring image information of the display module. In this way, the control device 101 may determine the cumulative mass flow measured by the flow meter 106 to be calibrated based on the image information acquired by the first acquisition device 103. For another example, when the flow meter 106 to be calibrated is used to measure the number of pulses of the fluid, the first acquisition device 103 may be a frequency counter for acquiring the number of pulses measured by the flow meter 106 to be calibrated. In this way, the control device 101 may determine the cumulative mass flow measured by the flow meter 106 to be calibrated based on the number of pulses and the pulse coefficient acquired by the first acquisition device 103.

[0057] Alternatively, the first acquisition device 103 may be a frequency counter for acquiring the pulse number measured by the flow meter to be calibrated 106. The control device 101 is further configured to determine the first flow information corresponding to the flow meter to be calibrated 106 according to the pulse number and the pulse coefficient of the flow meter to be calibrated 106.

[0058] The second acquisition device 104 is used to acquire the second flow information measured by the standard meter 102. For example, the standard meter 102 can be used to measure the number of pulses of the fluid, and the second acquisition device 104 can be a frequency counter, which is used to acquire the number of pulses measured by the standard meter 102. In this way, the control device 101 can determine the cumulative mass flow measured by the standard meter 102 based on the number of pulses and the pulse coefficient acquired by the second acquisition device 104.

[0059] The temperature transmitter 105 is used to measure the temperature of the fluid flowing through the standard meter 102 and send the measured fluid temperature to the control device 101 .

[0060] The control device 101 can control the working state of the first acquisition device 103 and the second acquisition device 104 according to the fluid temperature. For example, the control device 101 can control the working state of the first acquisition device 103 and the second acquisition device 104 to be turned on when the fluid temperature is in the temperature interval corresponding to the start of calibration. For another example, the control device 101 can control the working state of the first acquisition device 103 and the second acquisition device 104 to be turned off when the fluid temperature is not in the temperature interval corresponding to the start of calibration. Furthermore, the control device 101 can determine the error value corresponding to the flow meter 106 to be calibrated according to the first flow information and the second flow information.

[0061] The control device 101 is also used to control the working state of the first collection device 103 and the second collection device 104 to be turned on in multiple preset flow intervals. The multiple preset flow intervals include: 20%Q~50%Q, 50%Q~100%Q. Q is the maximum mass flow during calibration.

[0062] Or further, the control device 101 may obtain multiple groups of accumulated mass flow rates when the second flow information and the fluid temperature meet the calibration conditions, so as to further determine the error value for calibrating the flow meter to be calibrated.

[0063] Based on this, the present application can support the calibration of the flow meter to be calibrated 106 in the actual working scenario of the flow meter to be calibrated 106, avoiding the time-consuming disassembly and calibration of the flow meter to be calibrated 106 and the large error in the calibration result, so that the calibration data is more in line with the actual working conditions of the flow meter to be calibrated 106, thereby improving the accuracy of the calibration.

[0064] Combination Figure 1 The cryogenic liquid flow meter calibration system shown in Figure 2 As shown, it is a structural schematic diagram of another cryogenic liquid flow meter calibration system provided in an embodiment of the present application. Figure 2 The cryogenic liquid flow meter calibration system shown includes: a control device 101 , a standard meter 102 , a first acquisition device 103 , a second acquisition device 104 , a temperature transmitter 105 , a pressure transmitter 108 , a vent valve 111 , and a safety valve 112 .

[0065] The pressure transmitter 108 is used to measure the fluid pressure. The control device 101 is also used to adjust the second flow information of the standard meter 102 according to the fluid temperature and the fluid pressure.

[0066] exist Figure 2In the embodiment, the fluid device 107 can be a liquid source 109 or a storage tank 110. Quick-release connectors are provided at both ends of the standard meter 102, and are connected to the flow meter 106 to be calibrated and the storage tank 110 respectively through the quick-release connectors.

[0067] The drain valve 111 is arranged in the fluid pipeline at the output end of the standard meter 102, and can drain the fluid in the system under certain circumstances.

[0068] The safety valve 112 is set in the fluid pipeline at the input end of the standard meter 102, and is composed of a valve disc, a spring (or a loading device such as a weight), a valve seat, etc. Under normal circumstances, the safety valve 112 is in a closed state, and the fluid pressure in the pipeline is within the allowable range. When the fluid pressure in the pipeline exceeds the allowable range, the fluid can be discharged through the safety valve 112, thereby reducing the fluid pressure.

[0069] In terms of hardware implementation, the above control device can be implemented as follows: Figure 3 The structure shown is implemented. Figure 3 , which is a schematic diagram of the structure of a control device provided in an embodiment of the present application. Figure 3 The control device shown may include: a processor 201 , a memory 202 , a communication interface 203 , and a bus 204 . The processor 201 , the memory 202 , and the communication interface 203 may be connected via the bus 204 .

[0070] The processor 201 is the control center of the control device, and may be a general-purpose central processing unit (CPU) or other general-purpose processors, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0071] As an example, the processor 201 may include one or more CPUs, such as Figure 3 CPU 0 and CPU 1 are shown in .

[0072] The memory 202 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto.

[0073] In a possible implementation, the memory 202 may exist independently of the processor 201. The memory 202 may be connected to the processor 201 via a bus 204 and is used to store data, instructions, or program codes. When the processor 201 calls and executes the instructions or program codes stored in the memory 202, the recognition of the object to be recognized can be realized.

[0074] In another possible implementation, the memory 202 may also be integrated with the processor 201 .

[0075] The communication interface 203 is used to control the device to connect with other devices through a communication network, which may be Ethernet, a radio access network (RAN), a wireless local area network (WLAN), etc. The communication interface 203 may include a receiving unit for receiving data and a sending unit for sending data.

[0076] The bus 204 may be an industry standard architecture (ISA) bus, a peripheral component interconnect (PCI) bus, or an extended industry standard architecture (EISA) bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 3 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0077] It should be pointed out that Figure 3 The structure shown in the figure does not constitute a limitation on the control device, except Figure 3 In addition to the components shown, the control device may include more or fewer components than shown, or combine certain components, or arrange the components differently.

[0078] For ease of understanding, the cryogenic liquid flow meter calibration method provided in the present application is specifically introduced below with reference to the accompanying drawings.

[0079] like Figure 4 As shown, it is a schematic flow chart of a cryogenic liquid flow meter calibration method provided in the present application. Figure 4 The cryogenic liquid flow meter calibration method shown can be applied to the above Figures 1 to 3 The control device in the cryogenic liquid flow meter calibration system shown in any of the accompanying drawings, the method comprising: S301-S302.

[0080] S301. When the second flow information and the fluid temperature meet the calibration conditions, obtain multiple groups of accumulated mass flow rates.

[0081] The calibration condition is used to limit the mass flow point where the second flow information is located when the calibration starts, and the temperature range where the fluid temperature is located when the calibration starts.

[0082] Considering that the flow meter to be calibrated may have different measurement errors at different mass flow points, different mass flow points can be set for data collection. In this way, a set of cumulative mass flow includes a first flow information and a second flow information measured in the same collection period. The first flow information is the cumulative mass flow flowing through the flow meter to be calibrated in a collection period. The second flow information is the cumulative mass flow flowing through the standard meter in a collection period. Different groups of cumulative mass flow correspond to different mass flow points.

[0083] For example, considering that the instantaneous mass flow rate change value of the cryogenic liquid metering flowmeter during filling is small, data collection can be set in two flow intervals of 20%Q~50%Q and 50%Q~100%Q. Q is the maximum mass flow rate that can be added during calibration. Or further, the number of calibration tests in each flow interval can be no less than 3 times, and the duration of a single measurement can be greater than 1 minute. In this way, the flowmeter to be calibrated can be calibrated at different mass flow points in the two flow intervals.

[0084] It should be noted that before calibrating the flowmeter to be calibrated, the appearance, nameplate and normal working condition of the flowmeter to be calibrated can be checked. If the appearance of the flowmeter to be calibrated is intact, there is no mechanical damage that affects normal working, the switches and buttons are firm and function normally, and the display screen can display normally.

[0085] In addition, after connecting the flow meter to be calibrated to the cryogenic liquid flow meter calibration system and checking that there are no abnormalities at the connections of the piping system, in order to improve the accuracy of the calibration, the flow meter to be calibrated and the standard meter can be powered on for preheating, and the preheating time should be no less than 30 minutes.

[0086] At the same time, considering that the fluid may be a cryogenic liquid, that is, a fluid medium with a boiling point lower than -153°C (120K) at normal pressure, such as liquefied natural gas, liquid nitrogen, liquid hydrogen, liquid oxygen, liquid helium, etc., the cryogenic fluid source can be started to start filling with cryogenic fluid to pre-cool the flow meter to be calibrated.

[0087] In this case, the control device can collect the mass flow rate measured by the standard meter through the second collection device. The circulation flow time to reach more than 50% of the maximum mass flow rate of the cryogenic fluid of the standard meter should be no less than 5 minutes to complete the precooling of the flow meter to be calibrated. In this process, the cryogenic fluid can flow through the flow meter to be calibrated and the standard meter in turn, and be filled into the cryogenic fluid storage tank. During this period, based on the mass flow rate measured by the standard meter, the mass flow rate of the cryogenic fluid filling can be adjusted by adjusting the shut-off valve in the cryogenic fluid source or the motor frequency of the cryogenic submersible pump, reducing the pressure of the cryogenic fluid storage tank, etc.

[0088] The control device can determine whether to start data collection based on the mass flow rate (i.e., the second flow rate information) of the standard table and the fluid temperature collected by the temperature transmitter. If the mass flow rate of the cryogenic fluid meets the mass flow rate point when the calibration starts, and the fluid temperature of the cryogenic fluid meets the temperature range when the calibration starts, it is determined to start the calibration, and the first flow rate information of the flow meter to be calibrated is collected through the first collection device, and the second collection device is controlled to collect the second flow rate information of the standard table.

[0089] S302: Determine the error value corresponding to each mass flow point of the flow meter to be calibrated according to the multiple groups of accumulated mass flow rates, so as to calibrate the flow meter to be calibrated.

[0090] For a group of cumulative mass flow rates, the control device may determine the difference between the second flow information and the first flow information, the ratio of the difference between the second flow information and the first flow information in the same group of cumulative mass flow rates, that is, the difference between the cumulative mass flow rate collected by the standard table and the cumulative mass flow rate collected by the flow meter to be calibrated, as the error value of the mass flow point corresponding to the group of cumulative mass flow rates, for calibration of the flow meter to be calibrated.

[0091] Alternatively, after the control device determines the cumulative mass flow collected by the flow meter to be calibrated and the cumulative mass flow collected by the standard meter, it can also correct the cumulative mass flow collected by the standard meter based on the fluid temperature collected by the temperature transmitter, and further determine the difference between the corrected cumulative mass flow collected by the standard meter and the cumulative mass flow collected by the flow meter to be calibrated, and the ratio of the cumulative mass flow collected by the flow meter to be calibrated, as the error value of the mass flow point corresponding to the set of cumulative mass flow rates, for calibration of the flow meter to be calibrated.

[0092] Based on this, the present application can support the calibration of the flowmeter to be calibrated in the actual working scenario of the flowmeter to be calibrated, avoiding the time-consuming disassembly and calibration of the flowmeter to be calibrated, and the calibration medium used in the laboratory may be inconsistent with the medium actually used on site, resulting in large errors in the calibration results. In addition, the use of in-situ online calibration instead of traditional offline laboratory calibration can reduce the additional errors caused by offline verification. In this way, the control device can obtain multiple sets of cumulative mass flow rates when the second flow information and the fluid temperature meet the calibration conditions, so that the calibrated data is more in line with the actual working conditions of the flowmeter to be calibrated, thereby improving the accuracy of the calibration.

[0093] Furthermore, considering that the flow meter to be calibrated may have different measurement errors at different mass flow points, the present application can support the collection of multiple groups of cumulative mass flow rates at different mass flow points, and then determine the error values ​​corresponding to the flow meter to be calibrated at different mass flow points, so as to accurately calibrate the flow meter to be calibrated.

[0094] In one embodiment, the flow meter to be calibrated has a display module for displaying the accumulated mass flow rate. The first acquisition device is a camera device for acquiring image information of the display module. In this case, in the above S301, that is, when the control device obtains multiple groups of accumulated mass flow rates, the embodiment of the present application provides an optional implementation method, including: S3011-S3012.

[0095] S3011. Determine a starting mass flow rate based on a starting image, and determine a terminating mass flow rate based on a terminating image.

[0096] The start image is the image captured by the first acquisition device at the beginning of a collection period. The end image is the image captured by the first acquisition device at the end of a collection period. That is, within the collection period corresponding to a mass flow point, the first acquisition device can capture the start image and the end image respectively.

[0097] The control device can identify the start image and the end image respectively to determine the start mass flow rate and the end mass flow rate. The start mass flow rate is the cumulative mass flow rate measured by the flow meter to be calibrated at the beginning of the acquisition period. The end mass flow rate is the cumulative mass flow rate measured by the flow meter to be calibrated at the end of the acquisition period.

[0098] S3012. Determine the difference between the end mass flow rate and the start mass flow rate as the first flow rate information.

[0099] The first flow information is the accumulated mass flow passing through the standard meter within a collection period.

[0100] In one embodiment, the second acquisition device is a frequency counter for acquiring the number of pulses. In this case, in the above S301, that is, when the control device acquires multiple groups of accumulated mass flow rates, the embodiment of the present application provides an optional implementation method, including: S3013.

[0101] S3013. Divide the number of pulses of the standard meter by the pulse coefficient of the standard meter to obtain the second flow information.

[0102] The standard meter pulse number is the pulse number measured by the standard meter and collected by the second collection device within a collection period.

[0103] The control device may divide the number of pulses measured by the frequency counter in a collection period by the pulse coefficient of the standard meter to obtain the second flow information, ie, the accumulated mass flow passing through the standard meter in a collection period.

[0104] In one embodiment, in the above S302, that is, the control device determines the error value corresponding to each mass flow point of the flow meter to be calibrated based on multiple groups of cumulative mass flow rates for calibrating the flow meter to be calibrated, the embodiment of the present application provides an optional implementation method, including: S3021.

[0105] S3021. Determine the ratio of the difference between the second flow information and the first flow information in a group of cumulative mass flow to the first flow information in the same group of cumulative mass flow as the error value corresponding to the group of cumulative mass flow, and obtain the error value corresponding to each mass flow point of the flow meter to be calibrated.

[0106] That is, for a set of cumulative mass flow rates, the control device can determine the difference between the cumulative mass flow rates collected by the standard table and the cumulative mass flow rates collected by the flow meter to be calibrated, and the ratio of the difference to the cumulative mass flow rates collected by the flow meter to be calibrated, as the error value of the mass flow rate point corresponding to the set of cumulative mass flow rates, so as to calibrate the flow meter to be calibrated.

[0107] In one embodiment, in the above S302, that is, the control device determines the error value corresponding to each mass flow point of the flow meter to be calibrated based on multiple groups of cumulative mass flow rates for calibrating the flow meter to be calibrated, the embodiment of the present application provides another optional implementation method, including: S3022.

[0108] S3022. Determine an error value of a mass flow point corresponding to a set of cumulative mass flow rates according to the first formula and a set of cumulative mass flow rates, and obtain an error value corresponding to each mass flow point of the flow meter to be calibrated.

[0109] Among them, the first formula is:

[0110]

[0111] E is the preset post-calibration error corresponding to a mass flow point. The preset post-calibration error is the error expected to be achieved after the calibration of the cryogenic liquid flow meter to be calibrated. y is the second flow information in a set of cumulative mass flows. x is the first flow information in a set of cumulative mass flows. k is the error value corresponding to a mass flow point. Based on this, the control device can calculate the error value of the mass flow point corresponding to the set of cumulative mass flows according to the first formula after obtaining a set of cumulative mass flows.

[0112] In one embodiment, the cryogenic liquid flow meter calibration system may further include: a pressure transmitter. The pressure transmitter may be arranged at the input end or the output end of the standard meter to collect fluid pressure. In this case, the cryogenic liquid flow meter calibration method provided by the present application may further include:

[0113] S401. Adjust the second flow information according to the fluid temperature and the fluid pressure.

[0114] The fluid pressure is the pressure of the fluid when it flows through the standard gauge.

[0115] In order to improve the accuracy of calibration, the control equipment can calculate the density of the fluid under actual working conditions based on the fluid temperature and fluid pressure, and then correct the accumulated mass flow collected by the standard table to obtain a more accurate mass flow value, thereby determining a more accurate error value.

[0116] The above mainly introduces the scheme of the embodiment of the present application from the perspective of the method. It is understandable that in order to realize the above functions, the computer device includes at least one of the hardware structure and software modules corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present application.

[0117] The embodiment of the present application can divide the computer device into functional units according to the above method example. For example, each functional unit can be divided according to each function, or two or more functions can be integrated into one processing unit. The above integrated unit can be implemented in the form of hardware or in the form of software functional units. It should be noted that the division of units in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0118] For example, Figure 5A structural schematic diagram of a cryogenic liquid flow meter calibration device is shown. The cryogenic liquid flow meter calibration device 30 can be applied to a control device in a cryogenic liquid flow meter calibration system. The cryogenic liquid flow meter calibration system also includes: a first acquisition device, a standard meter, a second acquisition device, and a temperature transmitter. The control device is connected to the first acquisition device and the second acquisition device respectively. When the standard meter is working, it is connected in series with the flow meter to be calibrated and the fluid device. The fluid device is a device for the flow direction or outflow of the fluid in the actual working scene of the flow meter to be calibrated. The first acquisition device is used to acquire the first flow information measured by the flow meter to be calibrated. The second acquisition device is used to acquire the second flow information measured by the standard meter. The temperature transmitter is used to measure the temperature of the fluid flowing through the standard meter. The cryogenic liquid flow meter calibration device 30 includes: an acquisition unit 501 and a processing unit 502.

[0119] The acquisition unit 501 is used to acquire multiple groups of cumulative mass flow rates when the second flow rate information and the fluid temperature meet the calibration conditions. The calibration conditions are used to limit the mass flow rate point where the second flow rate information is located when the calibration starts, and the temperature range where the fluid temperature is located when the calibration starts. A group of cumulative mass flow rates includes a first flow rate information and a second flow rate information measured in the same acquisition period. Different groups of cumulative mass flow rates correspond to different mass flow rate points.

[0120] The processing unit 502 is used to determine the error value corresponding to each mass flow point of the flow meter to be calibrated according to the multiple groups of accumulated mass flow rates, so as to calibrate the flow meter to be calibrated.

[0121] In some embodiments, the acquisition unit 501 is specifically used to: determine the starting mass flow rate based on the starting image, and determine the ending mass flow rate based on the ending image. The starting image is an image acquired by the first acquisition device at the beginning of a collection period. The ending image is an image acquired by the first acquisition device at the end of a collection period. The difference between the ending mass flow rate and the starting mass flow rate is determined as the first flow information.

[0122] In some embodiments, the acquisition unit 501 is specifically configured to: determine the quotient of the standard meter pulse number divided by the standard meter pulse coefficient as the second flow information. The standard meter pulse number is the pulse number measured by the standard meter collected by the second collection device within a collection period.

[0123] In some embodiments, the processing unit 502 is further configured to adjust the second flow information according to the fluid temperature and the fluid pressure. The fluid pressure is the pressure of the fluid when it flows through the standard meter.

[0124] In some embodiments, the processing unit 502 is specifically used to: determine the difference between the second flow information and the first flow information in a group of cumulative mass flow, and the ratio of the difference between the second flow information and the first flow information in the same group of cumulative mass flow as an error value corresponding to a group of cumulative mass flow, and obtain the error value corresponding to each mass flow point of the flow meter to be calibrated.

[0125] In some embodiments, the fluid comprises a liquid having a boiling point below -153°C at normal pressure.

[0126] For the specific description of the above optional manner, please refer to the above method embodiment, which will not be repeated here. In addition, the explanation of any of the above computer devices and the description of the beneficial effects can refer to the above corresponding method embodiment, which will not be repeated here.

[0127] An embodiment of the present application further provides a readable storage medium having a computer program stored thereon. When the computer program is executed on a control device, the control device executes any of the methods executed by the control device provided above.

[0128] For the explanation of the relevant contents and description of the beneficial effects of any of the readable storage media provided above, reference may be made to the corresponding embodiments above, which will not be repeated here.

[0129] The embodiment of the present application also provides a computer program product including instructions, when the instructions are run on the control device, the control device executes any one of the methods in the above embodiments. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the control device, the process or function according to the embodiment of the present application is generated in whole or in part. The control device can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. Computer instructions can be stored in a readable storage medium, or transmitted from one readable storage medium to another readable storage medium. For example, computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The readable storage medium can be any available medium that the control device can access or a data storage device such as a server, data center, etc. that contains one or more servers that can be integrated with the medium. Available media can be magnetic media (e.g., floppy disks, hard disks, tapes), optical media (e.g., DVDs), etc.

[0130] It should be noted that the above-mentioned devices for storing computer instructions or computer programs provided in the embodiments of the present application, such as but not limited to the above-mentioned memories, readable storage media, etc., are all non-transitory.

[0131] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A cryogenic liquid flow meter calibration system, characterized in that: include: Control device, first acquisition device, standard table, second acquisition device, temperature transmitter; The control device is connected to the first acquisition device, the second acquisition device, and the temperature transmitter respectively; The standard meter is connected in series with the flow meter to be calibrated and the fluid device when working; the fluid device is the device where the fluid flows to or flows out of the actual working scene of the flow meter to be calibrated; The first acquisition device is used to acquire the first flow information measured by the flow meter to be calibrated; The second collection device is used to collect the second flow information measured by the standard meter; The temperature transmitter is used to measure the temperature of the fluid flowing through the standard meter; The control device is used to control the working states of the first collection device and the second collection device according to the fluid temperature; The control device is further used to determine an error value corresponding to the flow meter to be calibrated according to the first flow information and the second flow information.

2. The system according to claim 1, characterized in that The flow meter to be calibrated is provided with a display module for displaying the accumulated mass flow measured by the flow meter to be calibrated; the first acquisition device is a camera device for acquiring image information of the display module; The control device is further configured to obtain the first flow information from the image information.

3. The system according to claim 1, characterized in that The first acquisition device is a frequency counter, which is used to acquire the number of pulses measured by the flow meter to be calibrated; The control device is further used to determine first flow information corresponding to the flow meter to be calibrated according to the pulse number and the pulse coefficient of the flow meter to be calibrated.

4. The system according to claim 1, characterized in that The second acquisition device is a frequency counter, which is used to collect the number of pulses measured by the standard meter; The control device is also used to determine the second flow information corresponding to the standard table according to the pulse number and the pulse coefficient of the standard table.

5. The system according to claim 4, characterized in that Also includes: Pressure transmitter; The pressure transmitter is used to measure fluid pressure; The control device is also used to adjust the second flow information of the standard table according to the fluid temperature and the fluid pressure.

6. The system according to claim 1, characterized in that The two ends of the standard meter are provided with quick-release connectors, and are respectively connected to the flow meter to be calibrated and the fluid equipment through the quick-release connectors.

7. The system according to claim 1, characterized in that Also includes: Vent valve; the vent valve is arranged in the fluid pipeline at the output end of the standard meter.

8. The system according to claim 1, characterized in that Also includes: Safety valve; the safety valve is arranged in the fluid pipeline at the input end of the standard meter.

9. The system according to claim 1, characterized in that The fluid includes a liquid having a boiling point below -153°C at normal pressure.

10. The system according to claim 1, characterized in that The control device is also used to control the working state of the first collection device and the second collection device to be turned on in multiple preset flow intervals; The multiple preset flow rate intervals include: 20%Q-50%Q, 50%Q-100%Q, and Q is the maximum mass flow rate during calibration.

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