A real gas flow calibration control system and a real gas flow high-low temperature calibration system

Abstract

The application discloses a real gas flow calibration control system, which is characterized by comprising a host module, a memory, an input / output module, a power module and a communication module; a parameter acquisition module comprising a real gas parameter collector, a pulse isolation amplifier and a pulse / time measurement module; the real gas parameter collector is used for collecting the temperature, pressure and instantaneous flow of real gas in a real gas circulation loop, and the output side is signal-connected with the input / output module; the input side of the pulse isolation amplifier is signal-connected with a standard meter and a meter to be detected, and the output side is signal-connected with the input side of the pulse / time measurement module; the output side of the pulse / time measurement module is signal-connected with the input / output module; and the electric control actuating mechanism comprises a relay, an electric control valve, a flow driving control module and a temperature control module, which are signal-connected with corresponding interfaces of the input / output module. The application further discloses a real gas flow high / low temperature calibration system.

Description

Technical Field

[0001] This invention belongs to the field of actual gas flow rate calibration systems, and specifically relates to an actual gas flow rate calibration control system. Background Technology

[0002] Compared to traditional diaphragm gas meters, electronic gas meters equipped with emerging metering technologies such as MEMS and ultrasonic metering modules have significant advantages in terms of temperature and pressure correction, compact structure, and intelligent expansion, and are gradually gaining popularity in the market.

[0003] However, electronic gas meters exhibit significantly different metering characteristics under various operating conditions (different pressures, temperatures, or different media such as air, gas, or mixtures of different components). Therefore, the industry needs a solution to accurately obtain the metering characteristics and performance of different gas meters under various operating conditions, and to use this information to measure the metering error and aid in calibration, thereby improving the metering accuracy and reliability of different types of gas meters under different operating conditions.

[0004] The prior art patent document CN116539127A relates to a method, apparatus, equipment, and storage medium for calibrating a natural gas flow meter. Its technical solution includes: receiving a calibration request sent by a client, the request carrying the type of the flow meter to be calibrated and multiple flow points; determining a target standard pipeline associated with the flow meter based on its type; controlling the opening and closing of valves on the target standard pipeline to achieve the flow rate at each flow point; determining the calibration result of the flow meter at each flow point; determining the comprehensive calibration result of the flow meter based on the calibration results at each flow point; and sending the comprehensive calibration result to the client.

[0005] However, the existing technologies mentioned above still have shortcomings: the consistency of time synchronization of various parameters during the verification process directly affects the accuracy of the test results. This is something that the above solutions do not address.

[0006] Based on this, the applicant is considering designing a real gas flow rate calibration and control system and a real gas flow rate high and low temperature calibration system that can better ensure time synchronization consistency and obtain higher measurement accuracy. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is:

[0008] How to provide a real gas flow rate calibration and control system and a real gas flow rate high and low temperature calibration system that can better ensure time synchronization consistency and obtain higher measurement accuracy.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] A real gas flow rate calibration and control system, characterized in that it includes:

[0011] The host module includes a processor and a memory, an input / output module, a power supply module, and a communication module electrically connected to a corresponding interface on the processor;

[0012] The parameter acquisition module includes a gas parameter acquisition unit, a pulse isolation amplifier, and a pulse / time measurement module. The gas parameter acquisition unit is used to acquire the temperature, pressure, and instantaneous flow rate of the gas in the gas circulation loop during calibration, and its output side is connected to the input / output module. The input side of the pulse isolation amplifier is connected to the standard meter and the meter under test, and its output side is connected to the input side of the pulse / time measurement module. The output side of the pulse / time measurement module is connected to the input / output module.

[0013] The electronically controlled actuator includes a relay, an electronically controlled valve, a flow drive and control module, and a temperature control module whose control side interface is connected to the corresponding interface signal on the input / output module.

[0014] Compared with existing technologies, the advantages of this technical solution for the actual gas flow rate calibration and control system are:

[0015] 1. The entire system adopts a modular design, making it easier to install, maintain and use.

[0016] 2. The pulse signals collected during verification are accurate, achieving higher flow measurement accuracy and ensuring the precision of verification and control. Attached Figure Description

[0017] Figure 1 This is a block diagram illustrating the structural principle of the high and low temperature real gas flow rate calibration system in this technical solution.

[0018] Figure 2 This is a top view of the high and low temperature calibration system for actual gas flow rate in this technical solution.

[0019] Figure 3 This is a three-dimensional structural diagram of the high and low temperature calibration system for actual gas flow rate in this technical solution.

[0020] Figure 4 This is a top view of the high and low temperature calibration system for actual gas flow rate in this technical solution (the top and side walls of the standard meter installation room, the calibration room of the meter under test, and the control room are hidden).

[0021] Figure 5 for Figure 4 Enlarged view at point I

[0022] The diagram is marked as follows:

[0023] 0. Skid-mounted base:

[0024] 1. Real Gas Supply System: 11. Pressure Regulator, 12. Pressure Regulator Module, 13. Real Gas Storage Tank, 14. Gas Chromatograph

[0025] 2. Standard meter installation room: 21 Standard meter, 22 Explosion-proof exhaust fan

[0026] 3. Test Form Testing Room: 31 Test Forms, 32 Explosion-proof Exhaust Fans

[0027] 4. Flow-driven control module: 41. Fan, 42. Sonic nozzle assembly

[0028] Temperature control system:

[0029] 50 heat exchange container

[0030] 51 Cooling and Heating Unit: 510 Cooling and Heating Module, 511 Chilled Water Tank, 512 Hot Water Tank, 513 Cooling and Heating Controller

[0031] 52 air conditioner

[0032] 6. Control Room: 61. Verification and Control System

[0033] 7. Verification of the real gas circulation loop

[0034] 8 valves

[0035] 9 Explosion-proof vacuum pumps Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings.

[0037] like Figure 1 As shown, a real gas flow rate high and low temperature calibration system includes a calibration real gas circulation loop, in which a real gas supply system, a standard module, a calibration module and a flow drive control module are connected in series via a sealed pipeline; it also includes a temperature regulation system and a calibration control system;

[0038] The gas supply system is used to continuously output the calibration gas used in the calibration process, and an electrically controlled valve is installed on the gas pipeline at the output end.

[0039] The standard module includes a standard table; the calibration module includes at least one workstation to be inspected connected in series.

[0040] The flow-driven control module includes a fan and a flow-regulating sonic nozzle assembly, both of which are sealed and connected in series in the calibration gas circulation loop and can be adjusted in speed; the fan is a circulating fan, a centrifugal fan or an axial flow fan; the flow-regulating sonic nozzle assembly consists of multiple critical flow Venturi sonic nozzles connected in parallel and having various flow rates.

[0041] The temperature control module is used to regulate the temperature of the gas medium transported in the calibration gas circulation loop and the ambient temperature of the calibration module and the standard module.

[0042] The calibration and control system is used to control the real gas supply system, the flow drive regulation module, and the temperature control module.

[0043] During implementation, the testing stations include flow meter installation stations and / or at least two test meter installation stations connected in series; the flow meters under test are various types of gas flow meters, such as gas turbine flow meters, gas rotary flow meters, and ultrasonic flow meters; the test meters can be ultrasonic gas meters, MEMS thermal gas meters, diaphragm gas meters, etc. The installation stations for the flow meters and / or gas meters under test include flange interface testing fixtures and threaded interface testing fixtures, which can be adjusted according to flow meters of different diameters and lengths, as well as gas meters with different thread specifications and interface spacings, and are equipped with upstream and downstream straight pipe sections; each standard meter and test meter installation station is equipped with independent pressure and temperature measurement sensors.

[0044] During implementation, the system standard meter is preferably a high-precision three-rotor volumetric flow meter connected in series. For example, the standard meter can be a rotary flow meter with an accuracy class of less than or equal to 0.2.

[0045] During implementation, based on a high-precision three-rotor volumetric flow meter, critical flow venturi nozzles of various flow rates can be added to supplement the flow control points of the standard module.

[0046] In practice, in order to achieve (0.016~160)m 3 For a large flow rate range of / h, a single high-power, high-pressure variable frequency circulating fan can be used. This circulating fan is air-cooled and, through the combined adjustment of the frequency converter and flow regulator, can achieve a flow rate of (0.016~160)m³ / h. 3 Within a range of / h, the flow rate can be quickly and automatically adjusted according to the verification requirements; this better meets the simulation of working conditions with a large flow range and improves the versatility of the real gas flow high and low temperature verification system.

[0047] Compared with existing technologies, the advantages of this high and low temperature gas flow rate calibration system are:

[0048] 1. The real gas supply system can output any single component (methane, hydrogen, etc. as a medium) or mixed component (mixture of methane, propane, hydrogen or nitrogen, liquefied petroleum gas, etc.), more realistically simulating the working conditions of the gas meter in the present or future (different components, different temperatures, different pressures, different instantaneous flow rates, etc.), making the verification results more objective and accurate.

[0049] 2. The fan in the flow drive control module can achieve stepless speed regulation and has a larger speed regulation range, thereby enabling a wider range of flow regulation in the circulation channel, expanding the applicability of different flow meters / gas meters and improving practicality.

[0050] 3. The temperature control module can regulate the temperature of the actual gas, thereby better reproducing different working temperature conditions and more comprehensively simulating the calibration requirements of different regional temperature environments.

[0051] 4. The real gas supply system has functions of gas vacuuming, gas circulation, gas replacement, and gas venting.

[0052] 5. The real gas supply system adopts a combination of a high-accuracy standard flow meter and a critical flow venturi sonic nozzle, which can meet the calibration range requirements for both small and normal flow rates.

[0053] 6. The actual gas supply system adopts metering performance tests under special working conditions such as high and low temperatures and non-ideal flow fields to obtain the commonalities of the metering performance of flow meters (gas meters) under actual natural gas flow and complex working conditions, construct a metering performance evaluation model, and construct a compensation mechanism and adaptive correction model for flow meters under different temperature fields and non-ideal flow field conditions.

[0054] 7. In the gas industry, a metering performance testing device for flow meters (gas metering instruments) under complex operating conditions was developed for the first time, with "natural gas actual flow + high and low temperature conditions" as the core. This device enables rapid temperature control of the fluid and meets the testing requirements of flow meters (gas metering instruments) under complex operating conditions.

[0055] During implementation, the following electrical signals are acquired and processed as follows:

[0056] Verification control signals: Various control signals in the verification system enter the CPU card through AI / AO / DI / DO and other cards. The CPU card communicates with the verification computer through the bus protocol, and the verification software issues verification and control commands.

[0057] Acquisition of temperature / pressure / humidity / liquid level / flow meter signals (usually RS485 or HART signals): All measuring instruments such as pressure and temperature at the standard rotary flow meter and the flow meter / gas meter under test, as well as measuring instruments in the safety system and circulating cooling system, will be directly entered into the calibration system acquisition card. The calibration software will read these signals in real time through digital communication.

[0058] Video and light pulse signals are acquired through separate modules.

[0059] Process piping selection: The calibration software communicates the current set flow point and flow path selection information to the control system via the Modbus protocol. The control system automatically opens the switch valves on the standard flow path that need to be opened at the flow point in the calibration plan.

[0060] Temperature control: The temperature regulation system dynamically adjusts the temperature of the verification medium to the set temperature. The verifier only needs to set the target temperature for this verification in the verification plan, and usually no human intervention is required.

[0061] Pressure control: Manually adjust the pressure in the loop to the detection pressure.

[0062] Flow control: After the calibration begins, the calibration system automatically adjusts the flow rate of the calibration gas in the loop to the required flow rate through the frequency converter and flow regulator.

[0063] During implementation, the calibration gas circulation loop can have multiple process pipelines. Each process pipeline can be closed or opened by controlling the electrically controlled valves at the beginning and end of the relevant process pipelines. The parameters displayed for each process pipeline include: standard instantaneous volumetric flow rate, operating pressure and operating temperature, flow / pressure / temperature / humidity instrument status, and the status of each valve.

[0064] When using the real gas flow rate high and low temperature calibration system, the real gas flow rate calibration process can be described.

[0065] A process for verifying the flow rate of real gas includes the following steps:

[0066] Step 1: Prepare the calibration gas; load the instrument to be tested into the calibration gas circulation loop;

[0067] The second step is to open the calibration gas circulation loop and allow the gas flow within it to circulate; adjust and stabilize the operating temperature, instantaneous volumetric flow rate, and operating pressure of the gas in the calibration gas circulation loop to the preset values.

[0068] The third step is to enter the sampling period and continuously collect and store the measurement data of the standard meter and the meter under test, and verify the temperature, instantaneous volumetric flow rate and operating pressure of the gas in the gas circulation loop.

[0069] Step 4: Calculate and output the calibration data of the table under test based on the measurement data in Step 3.

[0070] During implementation, stabilizing to the preset value means:

[0071] The operating temperature stability requirement is that the operating temperature change should not exceed ±0.5℃ within one sampling period;

[0072] The operating pressure stability requirement is that the operating pressure change should not exceed ±0.5% within one sampling period;

[0073] The requirement for stable instantaneous volumetric flow rate under operating conditions is that the change in instantaneous volumetric flow rate under operating conditions within one sampling period should not exceed ±1% (≤4m³). 3 / h), ±0.5% (>4m 3 / h).

[0074] Compared with existing technologies, the actual gas flow rate verification process of this technical solution has the following advantages:

[0075] 1. Different types of gas meters (especially electronic gas meters) have a certain correlation between their metering accuracy (or metering error) and the actual gas composition they measure. This solution can configure actual gas, making the verification equivalent to verifying the gas meter using real gas. This allows us to obtain the metering accuracy and operational data of the gas meter under different operating conditions, and understand the adaptability of the gas meter to different gas compositions. This helps reduce metering losses and transmission errors in different countries and regions due to differences in natural gas composition or metered gas, resulting in more accurate metering and promoting technological advancements in emerging gas meters.

[0076] 2. Gas meters (flow meters) exhibit a certain correlation in measurement accuracy (or measurement error) under different pressures. This solution enables the verification of gas meters (flow meters) to be equivalent to verifying them using real gas pressure, thereby obtaining measurement accuracy and operational data of gas meters (flow meters) under different pressures, understanding the adaptability of gas meters under different pressures, and ultimately helping to reduce measurement losses and measurement errors of gas meters (flow meters) under different pressures.

[0077] 3. The structure of a gas meter (flow meter) will change under different temperature conditions, so there is a certain correlation between the metering accuracy (or metering error). This solution can make the verification equivalent to using the actual gas temperature to verify the gas meter (flow meter), thereby obtaining the metering accuracy and operation data of the gas meter (flow meter) at different temperatures, understanding the adaptability of the gas meter at different temperatures, and thus helping to reduce metering loss and metering error of the gas meter (flow meter) at different temperatures.

[0078] 4. Temperature-adjustable flow meter (gas metering instrument) for testing the actual flow measurement performance of natural gas, with a flow range of (0.016~160) m³ / s. 3 / h (standard operating conditions), temperature range (-25℃~+55℃), forming common characteristics of flow meter (gas metering instrument) metering characteristics under different media and complex operating conditions, and completing the establishment of flow meter (gas metering instrument) compensation mechanism and adaptive correction model under complex operating conditions.

[0079] 5. The implementation steps of this real gas flow rate calibration process are relatively reasonable. Completing the above four steps completes one calibration. After adjusting the actual gas composition or the operating temperature, instantaneous volumetric flow rate and operating pressure of the gas in the actual gas circulation loop, the actual gas operating parameters can be easily changed, and new calibration data can be measured.

[0080] In the third step, the measurement pulse signals generated by the standard meter and the meter under test during the calibration process are independently collected and recorded by a pulse counter after photoelectric shaping and amplification.

[0081] This improves signal acquisition quality, better removes noise interference, outputs stable signals, and increases acquisition accuracy.

[0082] Repeat steps one through four to complete the verification under different working conditions.

[0083] The specific calibration scheme setup process for implementing the actual gas flow rate calibration process is as follows:

[0084] After filling in the information of the flow meter under test, you will enter the calibration plan settings. The calibration plan needs to be configured with the following parameters:

[0085] ① Pre-run: When this option is selected, the system will pre-run for a specified time at the maximum flow point by default. The normal process will start after the pre-run time is over.

[0086] ②Stability judgment: If the temperature, pressure, or flow rate fluctuations exceed the set values ​​during the verification process, an error will be reported and a retry will be performed. If the number of retry attempts exceeds the set number, the verification will be judged as a failure.

[0087] ③ Number of samplings: The number of times each sampling point is sampled. After all data samplings are completed, the average error and repeatability are calculated.

[0088] ④ Sampling points: Manually enter the sampling points (m) 3 / h or %), you can directly enter the absolute value or the percentage (the percentage is calculated based on the maximum flow setting value in the basic information of the flow meter under test).

[0089] ⑤ Sampling time: Number of sampling pulses / sampling time (s). You can input the time or the number of pulses separately. Inputting the sampling time will update the number of sampling pulses, and inputting the number of sampling pulses will update the sampling time.

[0090] ⑥ Settling time: The time used to wait for the flow to stabilize before each sampling point.

[0091] ⑦ Standard flow meter number: Calculate in real time which standard flow meter is needed based on the specific flow rate at the sampling point.

[0092] ⑧ Add / Update: After entering the above parameters, click Add / Update to update the verification plan. If the current flow point already exists in the verification plan, the existing plan will be updated. If the current flow point is not in the verification plan, the verification point will be added to the verification plan. To delete the verification plan for a specific point, select the corresponding sampling point and click Delete.

[0093] ⑨ Estimated calibration time: Whenever a sampling point is added / updated / deleted or the K coefficient of the flowmeter under test is updated, a calibration time will be estimated on the right side of the calibration plan. This time is calculated based on the flow rate, sampling time, stabilization time, and pulse count. The value is for reference only, and the specific calibration time is determined according to the actual flow rate changes under operating conditions.

[0094] ⑩ Saving the verification plan: After the verification plan is configured, you can click "Save Verification Plan Template" to save the configuration information for this verification. If you need to verify the same flow meter of the same specification in the future, you can click "Open Verification Plan Template" to restore the last saved verification plan and perform the verification directly.

[0095] The temperature control system of the above-mentioned real gas flow high and low temperature calibration system includes a heat exchange module and a refrigeration and heating unit;

[0096] The heat exchange module has a sealed cavity for loading the cooling / heating medium, and the test gas circulation loop of the test gas flow high and low temperature test system has a section of heat exchange test gas delivery pipe made of thermally conductive metal material that seals through the sealed cavity.

[0097] The refrigeration / heating unit is used to circulate and supply refrigeration / heating medium into the sealed cavity of the heat exchange module, so that the heat exchange module can exchange heat with the actual gas transported in the actual gas circulation loop of the actual gas flow high and low temperature calibration system to achieve temperature regulation.

[0098] In practice, the thermally conductive metal material is stainless steel (304 or 316) or copper.

[0099] Compared with existing technologies, the temperature control system of the real gas flow high and low temperature calibration system in this technical solution has the following advantages:

[0100] 1. The system has a simple structure, making it easy to install one or more sets in the calibration gas circulation loop of the real gas flow high and low temperature calibration system to achieve one or more levels of temperature stability control requirements.

[0101] 2. Because each installation station of the flow meter under test and the meter under test is equipped with an independent temperature measurement sensor, the data from each temperature measurement sensor can be collected as a feedback signal, and the gas temperature in the gas circulation loop can be accurately controlled to achieve a true simulation of various gas temperature conditions.

[0102] Wherein, the cooling / heating medium is water;

[0103] The refrigeration and heating unit includes a refrigeration and heating module, a refrigeration water tank, and a hot water tank.

[0104] The refrigeration and heating module includes a compressor, a condenser, a dryer filter, a capillary tube, and an evaporator. The compressor's outlet pipe is sealed to the condenser's inlet, the condenser's outlet is sealed to one end of the dryer filter, the dryer filter's other end is sealed to one end of the capillary tube, the capillary tube's other end is sealed to one end of the evaporator, and the evaporator's other end is connected to the compressor's return pipe. The refrigeration and heating module's circulation piping is filled with refrigerant.

[0105] The evaporator is fixedly installed inside the cooling water tank, and the condenser is fixedly installed inside the hot water tank.

[0106] During implementation, any one of the refrigerants, such as R22, R410a, or R600a, can be used.

[0107] The working principle of the cooling and heating module in this technical solution is as follows:

[0108] The compressor processes the liquid refrigerant that enters through the return pipe into a high-temperature, high-pressure gaseous state. The gaseous refrigerant is output from the compressor's outlet pipe and enters the evaporator. In the evaporator, the refrigerant releases heat and changes from a liquid to a gaseous state. After passing through the dryer filter, the gaseous refrigerant is recompressed into a liquid state through the capillary tube. The liquid refrigerant expands and absorbs heat in the evaporator, changing from a liquid to a gaseous state. Finally, the gaseous refrigerant re-enters the compressor's return pipe.

[0109] This technical solution uses water as the cooling / heating medium. The advantages of using water are:

[0110] 1. Water is inexpensive and has low operating costs; water has a high specific heat capacity (4.2 × 10⁻⁶). 3 The temperature uniformity is good (J / (kg·℃)); and the noise is lower when the circulating water pump is running, making the working environment more friendly.

[0111] 2. The water has a wide temperature range (-5 to 100℃), which can meet the temperature range requirements of gas.

[0112] 3. Water has good thermal stability and its temperature changes more smoothly, which is more conducive to achieving precise temperature regulation and heat preservation.

[0113] In the high and low temperature calibration system for actual gas flow, the heat exchange module is provided on both the actual gas input side and the output side of the meter under test.

[0114] The heat exchange module includes a heat exchange container and a circulating water pump; the heat exchange container has a sealed cavity inside; the outer wall of the heat exchange container is also provided with a circulating water inlet and a circulating water outlet that are sealed and connected to its own interior.

[0115] The output port of the circulating water pump is sealed to the circulating water inlet, and the input port and the circulating water outlet of the circulating water pump are each sealed to the cooling water tank and the hot water tank through a three-way valve.

[0116] Because the real gas flow rate high and low temperature calibration system has a real gas circulation loop, the heat exchange module is installed on both the real gas input and output sides of the standard gauge and the real gas input and output sides of the gauge under test in the real gas flow rate high and low temperature calibration system. The heat exchange module on the input side can effectively regulate the temperature of the real gas entering the standard gauge and the gauge under test; the heat exchange module on the output side can effectively regulate and maintain the stability of the temperature of the real flow in the calibration real gas circulation loop, so as to achieve more precise temperature control.

[0117] In implementation, this technical solution employs a variable frequency controller for the circulating water pump to control its speed, thereby improving the regulation rate and temperature control accuracy. Simultaneously, it also includes a cooling and heating controller. This controller is connected to temperature measurement sensors installed on the input side pipes of each flowmeter and meter being tested in the high and low temperature calibration system for actual gas flow. The cooling and heating controller is also connected to the compressor, the variable frequency controller for the water pump, and the three-way valve to achieve precise temperature control of the actual gas.

[0118] The temperature control system includes a standard meter installation room and a test meter calibration room, which are independent of each other, each equipped with a door for personnel to enter and exit and each equipped with an air conditioner. The standard meter installation room is equipped with a pipeline section for installing the standard meter and the heat exchange module. The test meter calibration room is equipped with a pipeline section for installing the test meter and the heat exchange module.

[0119] After setting up the above-mentioned independent standard meter installation room and test meter calibration room with air conditioning and door structure, the indoor air environment can be conditioned by air conditioning, so that the temperature of the indoor air is close to that of the gas in the calibration gas circulation loop, thereby further reducing the temperature difference between the air outside the calibration gas circulation loop and the actual flow inside, and thus achieving more precise control of the temperature of the gas in the calibration gas circulation loop.

[0120] In practice, the cooling water tank can be a tank body with an outer heat insulation layer.

[0121] A real gas flow rate calibration and control system, comprising:

[0122] The host module includes a processor and a memory, an input / output module, a power supply module, and a communication module electrically connected to a corresponding interface on the processor;

[0123] The parameter acquisition module includes a gas parameter acquisition unit, a pulse isolation amplifier, and a pulse / time measurement module. The gas parameter acquisition unit is used to acquire the temperature, pressure, and instantaneous flow rate of the gas in the gas circulation loop during calibration, and its output side is connected to the input / output module. The input side of the pulse isolation amplifier is connected to the standard meter and the meter under test, and its output side is connected to the input side of the pulse / time measurement module. The output side of the pulse / time measurement module is connected to the input / output module.

[0124] The electronically controlled actuator includes a relay, an electronically controlled valve, a flow drive and control module, and a temperature control module whose control side interface is connected to the corresponding interface signal on the input / output module.

[0125] Compared with existing technologies, the advantages of this technical solution for the actual gas flow rate calibration and control system are:

[0126] 1. The entire system adopts a modular design, making it easier to install, maintain and use.

[0127] 2. The pulse signals collected during verification are accurate, achieving higher flow measurement accuracy and ensuring the precision of verification and control.

[0128] During implementation, the pulse / time measurement module adopts the iTS-PD high-precision multi-channel pulse / time detection unit. The frequency acquisition range of this detection unit can cover (0~10) kHz, and the acquisition accuracy is better than 0.001%. It can simultaneously measure up to 8 channels of instantaneous signals from standard meters and the meter under test. Each standard flow meter has an independent measurement channel, supporting up to 32 channels of detection.

[0129] In this technical solution, the pulse signal acquisition process is as follows: the pulse signals from the standard rotary flowmeter and the flowmeter under test are amplified by photoelectric shaping and then enter the pulse / frequency / time acquisition system. The pulse signals from both the tested and standard flowmeters enter the pulse counter independently and continuously, and are continuously read by the host module. The pulse data acquisition module achieves higher flow measurement accuracy through "dual timing processing" technology (first measuring a time period, then performing high-precision timing processing within that time period to obtain higher timing accuracy), ensuring the accuracy of calibration and control.

[0130] The flow drive control module includes a fan that is connected in series with the duct seal in the test gas circulation loop and can be adjusted in speed. The fan is a circulating fan, a centrifugal fan or an axial flow fan.

[0131] The temperature control module is used to regulate the temperature of the gas medium transported in the calibration gas circulation loop and the ambient temperature of the calibration module and the standard module.

[0132] The fan in the flow-driven control module can achieve stepless speed regulation and has a wider speed regulation range, thereby enabling a wider range of flow regulation in the circulation channel, expanding the applicability of different flow meters / gas meters and improving practicality.

[0133] The temperature control module can regulate the temperature of the actual gas, thereby better reproducing the temperature under different operating conditions and more comprehensively meeting the calibration needs of different temperature conditions.

[0134] The actual gas flow rate calibration and control system also includes a control room. The control room has a box-like structure and a door structure that allows personnel to enter and exit. An air conditioner, a fresh air system, and a power distribution cabinet are fixedly installed in the control room. The main unit module is located in the control room.

[0135] The control room setup allows operators to work independently, effectively avoiding sharing space with the actual gas circulation loop for actual gas testing, and effectively reducing the harm of noise and air pollution to the human body.

[0136] The control room has a heat insulation layer in the interlayer of the top wall and the four side walls, and the outer surface is made of hard metal.

[0137] In practice, the hard metal can be high-carbon steel or stainless steel.

[0138] This allows the side walls of the control room to have higher strength and better explosion-proof performance.

[0139] The control room has a grounding flat iron ring buried around its bottom perimeter. The grounding flat iron is electrically connected to the metal frame structure of the control room through a metal conductor.

[0140] In this way, the metal frame of the control room can be fully grounded by grounding flat iron, effectively avoiding the adverse effects caused by lightning strikes or static electricity, and better ensuring safety.

[0141] like Figures 1 to 4 As shown, the real gas supply system includes a pure gas module, a gas mixing module, and a component analysis module;

[0142] The pure gas module has multiple openable and closable pure gas output interfaces for outputting combustible gas and / or non-combustible gas.

[0143] The gas mixing module includes a gas storage tank that is sealed and connected to each of the pure gas output ports. The gas storage tank also has a gas output port equipped with a control valve and a check valve. The gas output port is used to connect to the calibration gas circulation loop through a three-way valve. The outer wall of the gas storage tank is also provided with a component detection port that is sealed and connected to the inner cavity.

[0144] The component analysis module includes an on / off valve, a pressure reducing valve, a one-way valve, and a gas chromatograph. The component detection interface of the gas storage tank is sequentially and sealed to the on / off valve, the pressure reducing valve, and the one-way valve via a pressure-resistant pipe, and then sealed to the gas detection interface of the gas chromatograph.

[0145] Compared with existing technologies, the advantages of this gas supply system are:

[0146] The system has a reasonable composition. The component analysis module can accurately detect the components of the mixed gas, and then flexibly configure the components of the actual gas according to the requirements of the verification conditions. This allows for a more realistic simulation of the working conditions, helping the verification system obtain more realistic and valuable verification data, improve correction accuracy, and enhance measurement precision.

[0147] In practice, gas chromatographs are mainly of two types: online and offline. Because the calibration gas circulation loop uses a high-pressure gas cylinder group for gas supply and the gas components are relatively simple, an offline gas chromatograph is used.

[0148] Wherein, the combustible gas is natural gas and / or hydrogen; the non-combustible gas is at least one of air, nitrogen or carbon dioxide.

[0149] In practice, the non-flammable gas source can be derived from the corresponding medium-pressure or high-pressure gas storage cylinder.

[0150] When the combustible gas is natural gas, the corresponding output interface is the output interface of the gas pressure regulating box.

[0151] A gas pressure regulating box can adjust the high-pressure gas delivered from the upstream pipeline to a lower and more stable pressure suitable for downstream user equipment.

[0152] When the combustible gas is hydrogen, the corresponding hydrogen output interface is a medium-pressure hydrogen cylinder or a high-pressure hydrogen cylinder.

[0153] Medium-pressure hydrogen cylinders (pressure between 10-30 MPa) and high-pressure hydrogen cylinders (pressure greater than 30 MPa).

[0154] The pure gas module and the mixed gas module are both installed in the open air and are fixedly installed at one end of the length direction of the long strip-shaped skid base. The control room is installed at the other end of the length direction of the skid base, and the standard meter installation room and the meter under test calibration room are installed in the middle of the length direction of the skid base.

[0155] This allows the gas supply system to be located away from the control room, improving the safety of the control room in emergency situations.

[0156] like Figures 2 to 4 As shown, the safety system of the real gas flow high and low temperature calibration system includes a standard meter installation room and a test meter calibration room, which are independent of each other, equipped with doors for personnel to enter and exit, and each has an air conditioner. The standard meter installation room is equipped with a pipeline section for installing the standard meter; the test meter calibration room is equipped with a pipeline section for installing the test meter; combustible gas sensors and alarms are fixedly installed in both the standard meter installation room and the test meter calibration room.

[0157] Compared with existing technologies, the safety system of the actual gas flow rate high and low temperature verification system in this technical solution has the following advantages:

[0158] 1. In the high and low temperature gas flow calibration system, the standard gauge and the gauge under test are installed in two separate rooms to achieve spatial isolation, which avoids the entire space from being affected by gas leakage in a single place, thus improving safety.

[0159] 2. The standard meter and the meter under test are installed in two separate rooms. The space in the two separate rooms is relatively small. Even if there is a slight leak, the concentration will be higher, making it easier for the combustible gas sensor in the room to detect and trigger the alarm, thus improving the level of safe operation.

[0160] In practice, the alarm device can be an audible and visual alarm.

[0161] The standard meter installation room and the test meter calibration room are each equipped with an explosion-proof exhaust fan fixedly installed on their respective side walls. The start control module of the explosion-proof exhaust fan is connected to the trigger signal output interface of the combustible gas alarm.

[0162] In this way, the explosion-proof exhaust fan can be activated immediately when the combustible gas alarm sends a detection signal to quickly expel combustible gas from the room to the outside, reduce the concentration of combustible gas, and prevent an explosion.

[0163] The power supply circuits of the high and low temperature gas flow calibration system's electrical cabinet and control cabinet are equipped with relays and circuit breakers that are connected to the trigger signal output of the combustible gas alarm.

[0164] Therefore, when the combustible gas alarm detects the concentration limit, the power supply circuit of the power cabinet and control cabinet can be automatically disconnected, effectively preventing the generation of electric arcs (electric sparks) and thus effectively preventing an explosion.

[0165] The walls, ceiling, and floor of both the standard meter installation room and the meter testing room are equipped with thermal insulation layers; the thermal insulation layers are at least one of rock wool, glass wool, or aerogel felt.

[0166] During implementation, the thermal insulation layer is an interlayer between the walls, ceiling, and floor.

[0167] The above-mentioned heat insulation layer not only has good heat insulation properties, but also has certain energy absorption, tensile strength and explosion-proof characteristics, which can reduce the external impact caused by explosion in extreme situations.

[0168] The standard meter installation room and the meter under test calibration room each have a grounding flat iron buried around their bottom perimeter. The grounding flat iron is electrically connected to the metal frame and the outer surface of the pipes inside the room through a metal conductor.

[0169] In this way, the metal frames of the standard meter installation chamber and the test meter calibration chamber, as well as the pipes inside, can be fully grounded by the grounding flat iron, effectively avoiding the adverse effects caused by lightning strikes or static electricity, and better ensuring safety.

[0170] The cooling water tank is a flat rectangular structure and is fixedly installed on the outer top surface shared by the standard meter installation room and the meter under test calibration room.

[0171] In practice, the sidewalls of the cooling water tank are made of corrosion-resistant thin metal (such as 1.5-3.5mm thick 304 or 316 stainless steel). The outer surface of the cooling water tank has a heat insulation layer, which is aluminum foil rubber-plastic insulation cotton. The aluminum foil rubber-plastic insulation cotton not only has good heat insulation properties, but the aluminum foil also has radiation protection properties, better preventing electromagnetic radiation interference to the indoor environment. At the same time, the aluminum foil rubber-plastic insulation cotton itself is flexible and can absorb energy during an explosive impact, reducing the explosive impact force and the degree of damage.

[0172] In this way, the cooling water tank will not occupy additional floor space, reducing the floor space required for the temperature control system. At the same time, it can make full use of the unused space on the top of the standard meter installation room and the meter testing room to fully expand the volume of the cooling water tank. With the increased volume of the cooling water tank, more water can be used to cool and store more energy at night when the unit price is lower. This energy can be released during peak electricity consumption times during the day (by regulating and reducing the actual gas temperature for testing), helping to reduce electricity costs and testing expenses.

[0173] In addition, placing the cooling water tank on the common outer roof surface of the standard meter installation room and the meter under test calibration room can absorb the energy of a flammable gas explosion in extreme cases. After the cooling water tank is damaged and holes are formed, the cooling water inside can flow out from the holes to cool down and extinguish the fire, playing a certain protective role and preventing the fire from spreading.

[0174] The above are merely preferred embodiments of the present invention. It should be noted that any modifications and improvements made by those skilled in the art without departing from the present technical solution should also be considered to fall within the scope of protection claimed in this claim.

Claims

1. A real gas flow rate high and low temperature calibration system, characterized in that, Including a real gas flow rate calibration and control system; The actual gas flow rate calibration and control system includes: The host module includes a processor and a memory, an input / output module, a power supply module, and a communication module electrically connected to a corresponding interface on the processor; The parameter acquisition module includes a gas parameter acquisition unit, a pulse isolation amplifier, and a pulse / time measurement module. The gas parameter acquisition unit is used to acquire the temperature, pressure, and instantaneous flow rate of the gas in the gas circulation loop during calibration, and its output side is connected to the input / output module. The input side of the pulse isolation amplifier is connected to the standard meter and the meter under test, and its output side is connected to the input side of the pulse / time measurement module. The output side of the pulse / time measurement module is connected to the input / output module. The electronically controlled actuator includes a relay, an electronically controlled valve, a flow drive and control module, and a temperature control module whose control side interface is connected to the corresponding interface signal on the input / output module; It also includes a calibration gas circulation loop, in which a gas supply system, a standard module, a calibration module, and a flow drive control module are connected in series via a sealed pipeline; it also includes a temperature control system; The gas supply system is used to continuously output the calibration gas used in the calibration process, and an electrically controlled valve is installed on the gas pipeline at the output end. The standard module includes a standard table; the calibration module includes at least one workstation to be inspected connected in series. The flow-driven control module includes a fan and a flow-regulating sonic nozzle assembly, both of which are sealed and connected in series in the calibration gas circulation loop and can be adjusted in speed; the fan is a circulating fan, a centrifugal fan or an axial flow fan; the flow-regulating sonic nozzle assembly consists of multiple critical flow Venturi sonic nozzles connected in parallel and having various flow rates. The temperature control module is used to regulate the temperature of the gas medium transported in the calibration gas circulation loop and the ambient temperature of the calibration module and the standard module. The calibration control system is used to control the gas supply system, the flow drive control module, and the temperature control module. In the gas flow high and low temperature calibration system, heat exchange modules are provided on both the gas input and output sides of the standard meter and the gas input and output sides of the meter under test. The heat exchange module on the input side can effectively regulate the temperature of the gas entering the standard meter and the meter under test. The heat exchange module on the output side can effectively regulate and maintain the temperature stability of the gas flow in the calibration gas circulation loop.

2. The real gas flow rate high and low temperature calibration system according to claim 1, characterized in that, It also includes a control room, which has a box-like structure and a door structure for personnel to enter and exit. An air conditioner, a fresh air system and a power distribution cabinet are fixedly installed in the control room; the main unit module is located in the control room.

3. The real gas flow rate high and low temperature calibration system according to claim 2, characterized in that, The control room's top and side walls are all fitted with heat-insulating layers, and the outer surfaces are made of hard metal.

4. The real gas flow rate high and low temperature calibration system according to claim 3, characterized in that: A grounding flat iron ring is buried in the ground around the bottom of the control room, and the grounding flat iron ring is electrically connected to the metal frame structure of the control room through a metal conductor.

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