Real gas flow verification process

Abstract

The invention discloses a real gas flow verification process, which is characterized by comprising the following steps of: 1, preparing real flow gas for verification; a detected meter is arranged in a detection real gas circulation loop; 2, opening a verification real gas circulation loop and enabling gas flow in the verification real gas circulation loop to circularly flow; adjusting and stabilizing the working condition temperature, the working condition instantaneous volume flow and the working condition pressure of the gas in the verification real gas circulation loop to preset values; 3, entering a sampling period, continuously collecting and storing metering data of the standard meter and the detected meter in the sampling period, and detecting the temperature, the working condition instantaneous volume flow rate and the working condition pressure of the gas in the real gas circulation loop; and 4, calculating and outputting verification data of the detected meter according to the metering data in the step 3. According to the invention, the metering precision and operation use data of the gas meter in different working conditions can be obtained, and the adaptability of the gas meter in different gas components can be known; therefore, metering is more accurate, and the novel gas meter is promoted to realize technical progress.

Description

Technical Field

[0001] The invention belongs to the field of gas meter calibration technology, and specifically relates to a real gas flow calibration technology. Background Art

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

[0003] However, electronic gas meters have different metering characteristics under different working conditions (different pressures, temperatures or different media such as air, gas, mixed gases of different components, etc.). Therefore, the industry needs a solution to accurately obtain the metering characteristics and performance of different gas meters under different working conditions, and to measure the metering error of the gas meter and help calibrate it, so as to improve the metering accuracy and stability and reliability of different types of gas meters under different working conditions.

[0004] The patent document with publication number CN117740120A in the prior art discloses an uncertainty analysis and evaluation method for an ultrasonic flowmeter under high temperature and high pressure conditions, comprising the following steps:

[0005] Step 1. By analyzing the working principle of the ultrasonic flowmeter and the flow field and flow state of the fluid in the pipeline, determine the input components that affect the mass flow measurement accuracy under high temperature and high pressure working conditions;

[0006] Step 2: Determine the calculation method of uncertainty introduced by density under high temperature and high pressure through direct and indirect temperature measurement methods;

[0007] Step 3. Through the real flow calibration test at normal temperature and pressure combined with the power supply voltage frequency influence test and the upstream disturbance flow influence test, the uncertainty calculation method of the flow calibration coefficient is given under the condition that the real flow calibration test at high temperature and pressure cannot be carried out;

[0008] Step 4. Determine the uncertainty evaluation method introduced by the deformation of the meter body and the acoustic channel geometry factor under high temperature and high pressure through finite element analysis of the meter body and high temperature and high pressure static test;

[0009] Step 5. Through high temperature and high pressure static tests, under the premise of ensuring that the fluid is stationary and the high temperature is stable, determine the errors introduced by the time items of the test transmission time, time difference, and zero point offset, and use this to calculate the uncertainty introduced by the time item;

[0010] Step 6. Verify the evaluation of other uncertainty influencing factors during the long-term operation of the flow meter through environmental change tests, transducer installation tests or other tests;

[0011] Step 7. Synthesize the uncertainty analysis and evaluation methods of Step 1 to Step 6 to obtain the final relative uncertainty of mass flow.

[0012] However, the above existing technologies still have the disadvantage that they do not take into account the influence of different components of real flow gas sources on the metering of different types of gas meters, and thus it is difficult to calibrate and analyze the metering characteristics and metering errors of different types of gas meters when applied to different real flow gas sources.

[0013] Based on this, the applicant considered designing a device that can better detect the metering characteristics of different types of gas meters used for real flow gas sources with different gas components, so as to better help design and manufacture gas meters with more accurate metering. Summary of the invention

[0014] In view of the above-mentioned deficiencies in the prior art, the technical problems to be solved by the present invention are:

[0015] How to provide a method that can better detect the metering characteristics of real flow gas sources of different types of gas meters used for different gas components, so as to better help design and manufacture gas meters with more accurate metering.

[0016] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0017] A real gas flow rate verification process comprises the following steps:

[0018] The first step is to prepare the real flow gas for calibration; put the meter to be tested into the calibration real gas circulation loop;

[0019] The second step is to open the test gas circulation loop and allow the gas flow therein to circulate; adjust and stabilize the working temperature, working instantaneous volume flow rate and working pressure of the gas in the test gas circulation loop to preset values;

[0020] Step 3: Enter the sampling period and continuously collect and store the metering data of the standard meter and the meter under test, and verify the temperature of the gas in the actual gas circulation loop, the instantaneous volume flow rate and the working pressure during the sampling period;

[0021] Step 4: Calculate and output the calibration data of the meter under test based on the measurement data in step 3.

[0022] Compared with the prior art, the gas flow verification process of this technical solution has the following advantages:

[0023] 1. There is a certain correlation between the metering accuracy (or metering error) of different types of gas meters (especially electronic gas meters) and the actual gas components being measured. This solution can configure real gas according to the actual situation, so that the calibration is equivalent to calibrating the gas meter with real gas, so as to obtain the metering accuracy and operation data of the gas meter under different working conditions, and understand the adaptability of the gas meter in different gas components. It can help different countries and regions reduce metering losses and metering transmission differences due to different natural gas components or different metering gases, making the measurement more accurate and promoting technological progress of emerging gas meters.

[0024] 2. There is a certain correlation in the measurement accuracy (or measurement error) of the gas meter (flow meter) under different pressures. This solution can make the calibration equivalent to calibrating the gas meter (flow meter) using the real gas pressure based on the actual pressure, so as to obtain the measurement accuracy and operation data of the gas meter (flow meter) under different pressures, and understand the adaptability of the gas meter under different pressures; thereby helping the gas meter (flow meter) under different pressures to reduce the measurement loss and measurement output difference.

[0025] 3. The structure of the gas meter (flow meter) will change under different temperature conditions, so there is a certain correlation in the measurement accuracy (or measurement error). This solution can make the calibration based on the actual temperature equivalent to calibrating the gas meter (flow meter) using the real gas temperature, so as to obtain the measurement accuracy and operation data of the gas meter (flow meter) at different temperatures, and understand the adaptability of the gas meter at different temperatures; thereby helping the gas meter (flow meter) at different temperatures to reduce the measurement loss and measurement output difference.

[0026] 4. Temperature adjustable flow meter (gas meter) natural gas flow metering performance test equipment, flow range (0.016~160)m 3 / h (standard operating conditions), temperature range (-25℃~+55℃), forming the common characteristics of the metering characteristics of flow meters (gas metering instruments) based on different media and complex working conditions, and completing the establishment of the compensation mechanism and adaptive correction model of flow meters (gas metering instruments) under complex working conditions.

[0027] 5. The implementation steps of this real gas flow calibration process are relatively reasonable. After completing the above four steps, a calibration is completed. After adjusting the actual flow gas components used for calibration or the operating temperature, operating instantaneous volume flow rate and operating pressure of the gas in the actual gas circulation loop, the actual flow operating parameters can be easily changed, and new calibration data can be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the principle diagram of the actual gas flow high and low temperature calibration system in this technical solution

[0029] Figure 2 A top view of the high and low temperature calibration system for real gas flow in this technical solution

[0030] Figure 3 Schematic diagram of the three-dimensional structure of the high and low temperature calibration system of the real gas flow in this technical solution

[0031] Figure 4 A top view of the high and low temperature calibration system for real gas flow in this technical solution (the top and side walls of the standard meter installation room, the meter to be tested calibration room and the control room are hidden)

[0032] Figure 5 for Figure 4 Enlarged view of point I

[0033] The markings in the figure are:

[0034] 0 Skid-mounted base:

[0035] 1 Gas supply system: 11 pressure regulating device, 12 pressure regulating module, 13 gas storage tank, 14 gas chromatograph

[0036] 2 Standard meter installation room: 21 standard meter, 22 explosion-proof exhaust fan

[0037] 3 Inspection room: 31 Inspection room, 32 Explosion-proof exhaust fan

[0038] 4 Flow drive control module: 41 fan, 42 sonic nozzle group

[0039] Temperature regulation system:

[0040] 50 heat exchange container

[0041] 51 Refrigeration and Heating Unit: 510 Refrigeration and Heating Module, 511 Refrigeration Water Tank, 512 Hot Water Tank, 513 Refrigeration and Heating Controller

[0042] 52 Air Conditioning

[0043] 6 Control Room: 61 Verification Control System

[0044] 7. Verify the actual gas circulation loop

[0045] 8 valves

[0046] 9. Explosion-proof vacuum pump DETAILED DESCRIPTION

[0047] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0048] A real gas flow rate verification process comprises the following steps:

[0049] The first step is to prepare the real flow gas for calibration; put the meter to be tested into the calibration real gas circulation loop;

[0050] The second step is to open the test gas circulation loop and allow the gas flow therein to circulate; adjust and stabilize the working temperature, working instantaneous volume flow rate and working pressure of the gas in the test gas circulation loop to preset values;

[0051] Step 3: Enter the sampling period and continuously collect and store the metering data of the standard meter and the meter under test, and verify the temperature of the gas in the actual gas circulation loop, the instantaneous volume flow rate and the working pressure during the sampling period;

[0052] Step 4: Calculate and output the calibration data of the meter under test based on the measurement data in step 3.

[0053] In practice, stabilization to a preset value means:

[0054] The working temperature stability requires that the working temperature change within a sampling period is no more than ±0.5℃;

[0055] The working pressure stability requires that the working pressure change within a sampling period is no more than ±0.5%;

[0056] The stability of the instantaneous volume flow rate under working conditions requires that the change of the instantaneous volume flow rate under working conditions within a sampling period should not exceed ±1% (≤4m 3 / h)、±0.5%(>4m 3 / h).

[0057] Compared with the prior art, the gas flow verification process of this technical solution has the following advantages:

[0058] 1. There is a certain correlation between the metering accuracy (or metering error) of different types of gas meters (especially electronic gas meters) and the actual gas components being measured. This solution can configure real gas according to the actual situation, so that the calibration is equivalent to calibrating the gas meter with real gas, so as to obtain the metering accuracy and operation data of the gas meter under different working conditions, and understand the adaptability of the gas meter in different gas components. It can help different countries and regions reduce metering losses and metering transmission differences due to different natural gas components or different metering gases, making the measurement more accurate and promoting technological progress of emerging gas meters.

[0059] 2. There is a certain correlation in the measurement accuracy (or measurement error) of the gas meter (flow meter) under different pressures. This solution can make the calibration equivalent to calibrating the gas meter (flow meter) using the real gas pressure based on the actual pressure, so as to obtain the measurement accuracy and operation data of the gas meter (flow meter) under different pressures, and understand the adaptability of the gas meter under different pressures; thereby helping the gas meter (flow meter) under different pressures to reduce the measurement loss and measurement output difference.

[0060] 3. The structure of the gas meter (flow meter) will change under different temperature conditions, so there is a certain correlation in the measurement accuracy (or measurement error). This solution can make the calibration based on the actual temperature equivalent to calibrating the gas meter (flow meter) using the real gas temperature, so as to obtain the measurement accuracy and operation data of the gas meter (flow meter) at different temperatures, and understand the adaptability of the gas meter at different temperatures; thereby helping the gas meter (flow meter) at different temperatures to reduce the measurement loss and measurement output difference.

[0061] 4. Temperature adjustable flow meter (gas meter) natural gas flow metering performance test equipment, flow range (0.016~160)m 3 / h (standard operating conditions), temperature range (-25℃~+55℃), forming the common characteristics of the metering characteristics of flow meters (gas metering instruments) based on different media and complex working conditions, and completing the establishment of the compensation mechanism and adaptive correction model of flow meters (gas metering instruments) under complex working conditions.

[0062] 5. The implementation steps of this real gas flow calibration process are relatively reasonable. After completing the above four steps, a calibration is completed. After adjusting the actual flow gas components used for calibration or the operating temperature, operating instantaneous volume flow rate and operating pressure of the gas in the actual gas circulation loop, the actual flow operating parameters can be easily changed, and new calibration data can be measured.

[0063] In the third step, the metering pulse signals generated by the standard meter and the meter under test during the calibration process are independently collected and recorded using a pulse counter after being photoelectrically shaped and amplified.

[0064] In this way, the signal acquisition quality can be improved, noise interference can be better removed, stable signals can be output, and acquisition accuracy can be improved.

[0065] Repeat steps 1 to 4 to complete the calibration of different working conditions.

[0066] The specific process of setting up the verification scheme when implementing the actual gas flow verification process is as follows:

[0067] After filling in the information of the flow meter to be inspected, the calibration plan setting will be entered. The calibration plan needs to configure the following parameters:

[0068] ① Pre-run: When this option is checked, the system will pre-run for a specified time with the maximum flow point as the set point by default, and the normal process will start after the pre-run time ends.

[0069] ② Stability judgment: If it is found during the calibration process that the temperature, pressure, and flow fluctuation range exceeds the set value, an error will be reported and a retry will be performed. After the number of retries exceeds the limit, the calibration will be judged as a failure.

[0070] ③ Number of sampling times: The number of sampling times for each sampling point. When all data sampling times are completed, calculate the average error and repeatability.

[0071] ④ Sampling point: Manually fill in the sampling point (m 3 / h or %), you can directly enter an absolute value or a percentage (the percentage is calculated based on the maximum flow setting value in the basic information of the flow meter being tested).

[0072] ⑤ Sampling time: sampling pulse number / sampling time (s). You can enter the time or pulse number separately. If you enter the sampling time, the sampling pulse number will be updated. If you enter the sampling pulse number, the sampling time will be updated.

[0073] ⑥Stabilization time: The time used to wait for the flow to stabilize before each sampling point.

[0074] ⑦ Standard flow meter number: Calculate in real time which standard flow meter is needed based on the specific flow at the sampling point.

[0075] ⑧ Add / Update: After entering the above parameters, click Add / Update to update the calibration plan. If the current flow point already exists in the calibration plan, update the existing plan. If the current flow point is not in the calibration plan, add the calibration point to the calibration plan. If you need to delete the calibration plan for a certain point, select the corresponding sampling point and click Delete.

[0076] ⑨ Estimated calibration time: Whenever a sampling point is added / updated / deleted or the K coefficient of the flow meter being tested 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 number of pulses. The value is for reference only. The specific calibration time is determined based on changes in actual operating flow.

[0077] ⑩Save the calibration plan: After the calibration plan configuration is completed, you can click Save calibration plan template to save the configuration information of this calibration. If you calibrate the flow meter of the same specification in the future, you can click Open calibration plan template, restore the last saved calibration plan and perform calibration directly.

[0078] The actual gas flow verification process in this scheme uses the following actual gas flow high and low temperature verification system:

[0079] like Figure 1 As shown, a real gas flow high and low temperature calibration system includes a calibration real gas circulation loop, in which a real gas supply system, a standard device module, a calibration module and a flow drive control module are connected in series through pipeline sealing; it also includes a temperature adjustment system and a calibration control system;

[0080] The real gas supply system is used to continuously output the test gas used in the test process, and an electric control valve is installed on the gas pipeline at the output end;

[0081] The standard device module includes a standard table; the verification module includes at least one verified station connected in series;

[0082] The flow drive control module comprises a fan and a flow regulating sonic nozzle group which are sealed and connected in series in the test gas circulation loop and both of which are adjustable in speed; the fan is a circulation fan, a centrifugal fan or an axial flow fan; the flow regulating sonic nozzle group is composed of a plurality of critical flow Venturi sonic nozzles which are connected in parallel and have various flow specifications;

[0083] The temperature control module is used to control the temperature of the gas medium transported in the calibration gas circulation loop and the ambient temperature of the calibration module and the standard device module;

[0084] The verification control system is used to control the real gas supply system, the flow drive regulation module and the temperature control module.

[0085] During implementation, the inspected station includes a flow meter installation station or / and at least two inspected meter installation stations connected in series; the inspected flow meter is a gas turbine flow meter or a gas rotary flow meter, an ultrasonic flow meter or other gas flow meter types; the inspected meter can be: an ultrasonic gas meter, a MEMS thermal gas meter, a membrane gas meter or other types. The installation station of the inspected flow meter or / and gas meter includes a flange interface test fixture and a threaded interface test fixture, which can be adjusted according to flow meters of different calibers and lengths and gas meters of different thread specifications and different interface spacings, and is equipped with front and rear straight pipe sections; each standard meter and inspected meter installation station is equipped with independent pressure and temperature measurement sensors.

[0086] During implementation, the system standard meter is preferably a high-precision three-rotor positive displacement flow meter connected in series. For example, the standard meter can use a rotary flow meter with an accuracy level of less than or equal to 0.2.

[0087] During implementation, on the basis of the high-precision three-rotor positive displacement flowmeter, critical flow Venturi sonic nozzles with flow rates of various specifications can be added to supplement the flow control points of the standard module.

[0088] During implementation, in order to achieve (0.016~160)m 3 / h large flow range, the fan can use a high-power high-pressure variable frequency circulation fan, the circulation fan is air-cooled design, through the comprehensive adjustment of the frequency converter and flow regulator, can achieve (0.016 ~ 160) m 3 / h range according to the verification requirements to quickly and automatically adjust the flow; better meet the simulation of working conditions in a large flow range, and improve the versatility of the actual gas flow high and low temperature verification system.

[0089] Compared with the prior art, the advantages of the high and low temperature calibration system of the actual gas flow in this technical solution are:

[0090] 1. The real gas supply system can output any single component (methane, hydrogen, etc. as 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 actual use (different components, different temperatures, different pressures, different instantaneous flow rates, etc.), making the calibration results more objective and accurate.

[0091] 2. The fan in the flow drive control module can achieve stepless speed regulation and has a larger speed regulation range, so that a wider range of flow regulation can be achieved in the circulation flow channel, expanding the scope of application of calibrating different flow meters / gas meters and improving practicality.

[0092] 3. The temperature control module can adjust the temperature of the real gas, thereby better reproducing the temperature conditions of different working conditions and more comprehensively simulating the calibration requirements of temperature environments in different regions.

[0093] 4. The actual gas supply system has the functions of gas vacuuming, gas circulation, gas replacement and gas venting.

[0094] 5. The actual 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 of small flow and normal flow.

[0095] 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 commonality of metering performance of flow meters (gas meters) under real natural gas flow and complex working conditions, build a metering performance evaluation model, and build a compensation mechanism and adaptive correction model for flow meters under different temperature fields and non-ideal flow field conditions.

[0096] 7. In the gas industry, for the first time, a flow meter (gas metering instrument) complex operating condition measurement performance test device with "natural gas real flow + high and low temperature conditions" as the core was developed to achieve rapid fluid temperature control and meet the detection needs of flow meters (gas metering instruments) under complex working conditions.

[0097] During implementation, the following electrical signals are collected and processed respectively:

[0098] Verification control signal: Various control signals in the verification system enter the CPU card through AI / AO / DI / DO and other card components. The CPU card communicates with the verification computer through the bus protocol, and the verification software issues verification and control instructions.

[0099] Temperature / pressure / humidity / liquid level / flow instrument signal (usually RS485 or HART signal) collection: All measuring instruments such as pressure, temperature, etc. of standard rotary flowmeters and flowmeters / gas meters under test, as well as measuring instruments in safety systems and circulating cooling systems will directly enter the calibration system acquisition card, and the calibration software will read these signals in real time through digital communication.

[0100] The video and light pulse signals are collected through independent modules.

[0101] Process pipeline selection: The calibration software communicates the current set flow point and flow selection information to the control system through the Modbus protocol, and the control system automatically opens the switch valve on the standard table flow path that needs to be opened at the flow point in the calibration plan.

[0102] Temperature control: The temperature control system dynamically adjusts the temperature of the calibration medium to the set temperature. The calibrator only needs to set the target temperature for this calibration in the calibration plan. Normally, no human intervention is required.

[0103] Pressure control: Manually adjust the pressure in the loop to the detection pressure.

[0104] Flow control: After the calibration starts, the calibration system automatically adjusts the calibration gas flow in the loop to the flow required for the calibration through the frequency converter and flow regulator.

[0105] During implementation, the actual gas circulation loop to be verified may have multiple process pipelines, and each process pipeline can be closed or opened by controlling the electric control valves at the beginning and end of the relevant process pipelines. The parameters displayed for each process pipeline include: standard instantaneous volume flow, operating pressure and operating temperature, flow / pressure / temperature / humidity instrument status and each valve status.

[0106] When the actual gas flow high and low temperature calibration system is in use, the actual gas flow calibration process can be carried out.

[0107] The temperature regulation system of the above actual gas flow high and low temperature verification system includes a heat exchange module and a refrigeration and heating unit;

[0108] The heat exchange module has a sealed cavity for loading cooling / heating medium inside, and the test gas circulation loop of the gas flow high and low temperature test system has a heat exchange gas delivery pipe made of heat conductive metal material that seals and penetrates the sealed cavity;

[0109] Among them, the refrigeration and heating unit is used to circulate the refrigeration / heating medium into the sealed cavity of the heat exchange module, so that the heat exchange module can exchange heat with the real gas transported in the calibration real gas circulation loop of the real gas flow high and low temperature calibration system to achieve temperature control.

[0110] During implementation, the heat-conducting metal material is stainless steel (304 or 316) or copper.

[0111] Compared with the prior art, the temperature regulation system of the real gas flow high and low temperature verification system in this technical solution has the following advantages:

[0112] 1. The system structure is simple, which makes it easy to arrange and install one or more sets in the calibration real gas circulation loop of the real gas flow high and low temperature calibration system to achieve the first or multi-level temperature stabilization control requirements.

[0113] 2. Because each flow meter installation station and meter installation station are equipped with independent temperature measurement sensors, the data of each temperature measurement sensor can be collected as feedback signals, and the feedback signals can be used to accurately control the gas temperature in the actual gas circulation loop, so as to realize the real simulation of various actual gas temperature conditions.

[0114] Wherein, the cooling / heating medium is water;

[0115] The refrigeration and heating unit comprises a refrigeration and heating module, a refrigeration water tank and a hot water tank;

[0116] The cooling and heating module comprises a compressor, a condenser, a drying filter, a capillary tube and an evaporator; the outlet pipe interface of the compressor is sealed and connected with the input end of the condenser, the output end of the condenser is sealed and connected with one end of the drying filter, the other end of the drying filter is sealed and connected with one end of the capillary tube, the other end of the capillary tube is sealed and connected with one end of the evaporator, and the other end of the evaporator is connected with the return pipe interface of the compressor; refrigerant is injected into the circulation pipeline of the cooling and heating module;

[0117] The evaporator is integrally fixedly installed in the refrigeration water tank, and the condenser is integrally fixedly installed in the hot water tank.

[0118] During implementation, the refrigerant may be any one of R22, R410a or R600a.

[0119] The working principle of the cooling and heating module in this technical solution is:

[0120] The compressor processes the liquid refrigerant entering through the return air pipe into a high-temperature and high-pressure gas. The gas is output from the compressor outlet pipe interface and enters the evaporator. The refrigerant in the evaporator releases heat and changes from liquid to gas. After passing through the drying filter, the gaseous refrigerant is re-compressed into liquid through the capillary tube. The liquid refrigerant expands in the evaporator, absorbs heat, cools, and changes from liquid to gas. The gaseous refrigerant finally re-enters the return air end of the compressor.

[0121] The advantages of using water as the cooling / heating medium in this technical solution are:

[0122] 1. Water is cheap and has low use cost; water has a large specific heat capacity (4.2×10 3 J / (kg·℃)), good temperature uniformity; and combined with the circulating water pump, lower noise during operation, making the working environment more friendly.

[0123] 2. The water temperature adjustment range is wide (-5 to 100°C), which can meet the gas temperature adjustment range requirements.

[0124] 3. Water has better thermal stability and more stable temperature changes, which is more conducive to precise temperature control and heat preservation.

[0125] Wherein, the heat exchange module is provided on both the real gas input side and the output side of the meter under test in the real gas flow high and low temperature test system;

[0126] The heat exchange module comprises a heat exchange container and a circulating water pump; the interior of the heat exchange container has the sealed chamber; the outer wall of the heat exchange container is also provided with a circulating water inlet and a circulating water outlet which are sealed and connected with the interior of the heat exchange container;

[0127] The output port of the circulating water pump is sealed and connected with the circulating water inlet, and the input port and the circulating water outlet of the circulating water pump are respectively sealed and connected with the refrigerating water tank and the hot water tank through a three-way valve.

[0128] Because the real gas flow high and low temperature calibration system has a calibration real gas circulation loop, the heat exchange module is provided on the real gas input side and output side of the standard meter and the real gas input side and output side of the meter being tested in the real gas flow high and low temperature calibration system. The heat exchange module on the input side can effectively regulate the real gas temperature entering the standard meter and the meter being tested; 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 better realize precise temperature control.

[0129] During implementation, in this technical solution: the circulating water pump adopts a water pump frequency conversion controller to control the water pump speed by frequency conversion, so as to improve the regulation rate and constant temperature accuracy; at the same time, it also includes a refrigeration and heating controller, which is connected to the temperature measurement sensor signal installed on the input side pipeline of each flow meter installation station and the meter installation station in the real gas flow high and low temperature calibration system. The refrigeration and heating controller is also connected to the compressor, water pump frequency conversion controller and three-way valve control to achieve precise temperature control of the real gas.

[0130] Among them, the temperature control system also includes a standard meter installation room and a tested meter calibration room, which are independent of each other, equipped with doors for personnel to enter and exit, and each equipped with air conditioners; the standard meter installation room is provided with a pipeline section for the installation of the standard meter and the heat exchange module; the tested meter calibration room is provided with a pipeline section for the installation of the tested meter and the heat exchange module.

[0131] After setting up the above-mentioned independent standard meter installation room and the meter under test calibration room with air conditioning and door structure, the indoor air environment can be temperature-controlled by air conditioning, so that the temperature of the indoor air is close to the temperature of the gas in the calibration real air circulation loop, thereby further reducing the temperature difference between the air outside the calibration real air circulation loop and the real flow inside, and realizing more precise control of the temperature of the gas in the calibration real air circulation loop.

[0132] During implementation, the refrigeration water tank may adopt a tank body with a thermal insulation layer installed on the outside.

[0133] A real gas flow verification control system, comprising:

[0134] A host module, including a processor and a memory, an input / output module, a power module, and a communication module electrically connected to a corresponding interface on the processor;

[0135] The parameter acquisition module includes a real gas parameter collector, a pulse isolation amplifier and a pulse / time measurement module; the real gas parameter collector is used to collect the temperature, pressure and instantaneous flow of the real gas in the real gas circulation loop, and the output side is connected to the input / output module signal; the input side of the pulse isolation amplifier is used to connect to the standard meter and the meter under test signal, and the output side is used to connect to the input side signal of the pulse / time measurement module; the output side of the pulse / time measurement module is connected to the input / output module signal;

[0136] The electric control actuator comprises a relay, an electric control valve, a flow drive control module and a temperature control module, the control side interface of which is connected with the corresponding interface signal on the input / output module.

[0137] Compared with the prior art, the advantages of the gas flow verification control system of this technical solution are:

[0138] 1. The entire system adopts a modular design, which is easier to install, maintain and use.

[0139] 2. The pulse signal collected during verification is accurate, which can achieve higher flow measurement accuracy and ensure the accuracy of verification and control.

[0140] During implementation, the pulse / time measurement module uses 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 standard meters and instantaneous signals of the meter under test. Each standard flow meter has an independent measurement channel, supporting up to 32 channels of detection.

[0141] The pulse signal acquisition process in this technical solution is as follows: the pulse signals of the standard rotary flowmeter and the flowmeter under test enter the pulse / frequency / time acquisition system after being photoelectrically shaped and amplified. The pulse signals of the meter under test and the standard meter 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 the "double timing processing" technology (first measuring a time period, and then performing high-precision timing processing within the time period to obtain higher timing accuracy), ensuring the accuracy of verification and control.

[0142] Wherein, the flow drive control module includes a fan which is connected in series with the air duct seal in the test air circulation loop and can be speed-adjustable, and the fan is a circulation fan, a centrifugal fan or an axial flow fan;

[0143] The temperature control module is used to control the temperature of the gas medium transported in the calibration gas circulation loop and the ambient temperature of the calibration module and the standard device module.

[0144] The fan in the flow drive control module can achieve stepless speed regulation and has a larger speed regulation range, so that a wider range of flow regulation can be achieved in the circulation flow channel, expanding the scope of application of calibrating different flow meters / gas meters and improving practicality.

[0145] The temperature control module can adjust the temperature of the actual gas, thereby better reproducing the temperatures of different working conditions and more comprehensively meeting the calibration requirements of different temperature conditions.

[0146] Among them, the actual gas flow calibration control system also includes a control room. The overall appearance of the control room is a box-type structure and has a door structure for people to enter and exit. The control room is fixedly installed with an air conditioner, a fresh air system and a distribution cabinet; the host module is arranged in the control room.

[0147] The setting of the control room enables the operators to work independently in the control room, effectively avoiding sharing the space with the real gas circulation loop of the real gas test, and effectively reducing the harm of noise and air environment to the human body.

[0148] The interlayers of the top wall and the surrounding side walls of the control room are provided with heat-insulating layers and the outer side surfaces are made of hard metal.

[0149] During implementation, the hard metal may be high carbon steel or stainless steel.

[0150] This can make the side walls of the control room stronger and more explosion-proof.

[0151] Wherein, a circle of grounding flat iron is buried in the ground around the bottom of the control room, and the grounding flat iron is electrically connected to the metal frame structure of the control room through a metal conductor.

[0152] In this way, the metal frame of the control room can be fully grounded through the grounding flat iron, effectively avoiding the adverse effects caused by lightning strikes or static electricity and better ensuring safety.

[0153] like Figures 1 to 4 As shown, the real gas supply system includes a pure gas module, a mixed gas module and a component analysis module;

[0154] The pure gas module has a plurality of pure gas output interfaces for outputting combustible gas and / or non-combustible gas and which can be opened and closed;

[0155] The gas mixing module includes a real gas storage tank sealed and connected to each of the pure gas output interfaces, the real gas storage tank also has a real gas output interface installed with a control valve and a one-way valve, and the real gas output interface is used to connect to the real gas circulation loop for verification through a three-way connection; the outer wall of the real gas storage tank is also provided with a component detection interface sealed and connected to the inner cavity;

[0156] 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 real gas storage tank is sealed and connected to the on-off valve, the pressure reducing valve and the one-way valve in sequence through a pressure-resistant pipe, and then to the gas detection interface of the gas chromatograph.

[0157] Compared with the prior art, the advantages of the gas supply system of this technical solution are:

[0158] The system composition is reasonable, and the mixed gas components can be accurately detected through the component analysis module, and then the components of the real gas can be flexibly configured according to the requirements of the calibration conditions, so as to simulate the working conditions more realistically, help the calibration system to obtain more real and valuable calibration data, improve correction accuracy, and enhance measurement accuracy.

[0159] During implementation, there are mainly two types of gas chromatographs: online and offline. Because the real gas circulation loop for calibration uses a high-pressure gas cylinder group to supply gas, the gas composition is relatively simple, so an offline chromatograph is used.

[0160] Wherein, the combustible gas is natural gas and / or hydrogen; the non-combustible gas is at least one of air, nitrogen or carbon dioxide.

[0161] During implementation, the non-combustible gas source may all be derived from a corresponding medium-pressure or high-pressure gas storage cylinder.

[0162] Wherein, when the combustible gas is natural gas, the corresponding output interface is the output interface of the gas pressure regulating box.

[0163] The gas pressure regulating box can adjust the higher pressure gas delivered from the upstream pipeline to a lower and stable pressure suitable for use by downstream user equipment.

[0164] Wherein, when the combustible gas is hydrogen, the corresponding hydrogen output interface is a medium-pressure hydrogen cylinder or a high-pressure hydrogen cylinder.

[0165] Medium-pressure hydrogen cylinders (pressure between 10-30MPa) and high-pressure hydrogen cylinders (pressure greater than 30MPa).

[0166] Among them, the pure gas module and the mixed gas module are both installed in the open air and fixed as a whole at one end of the length direction of the long skid-mounted base, the other end of the skid-mounted base in the length direction is installed with a control room, and the middle part of the skid-mounted base in the length direction is installed with a standard meter installation room and a calibration room for the meter under test.

[0167] In this way, the actual gas supply system can be kept away from the control room, improving the safety of the control room in emergency situations.

[0168] like Figures 2 to 4 As shown, the safety system of the actual gas flow high and low temperature calibration system includes a standard meter installation room and a calibration room for the meter to be tested, which are independent of each other, equipped with doors for personnel to enter and exit, and each is equipped with air conditioning; the standard meter installation room is provided with a pipeline section for the installation of the standard meter; the calibration room of the meter to be tested is provided with a pipeline section for the installation of the meter to be tested; both the standard meter installation room and the calibration room of the meter to be tested are fixedly equipped with combustible gas sensors and alarms.

[0169] Compared with the prior art, the safety system of the high and low temperature calibration system of the actual gas flow in this technical solution has the following advantages:

[0170] 1. The standard meter and the meter to be tested in the actual gas flow high and low temperature calibration system are installed in two independent rooms to achieve spatial isolation, avoid the impact of gas leakage in a single place on the equipment in the entire space, and improve safety.

[0171] 2. The standard meter and the meter under test are installed in two independent rooms. The relative space between the two independent rooms is smaller. Once a slight leak occurs, its concentration can be higher, which is easier to be detected by the indoor combustible gas sensor and trigger the alarm, thereby improving the safety level of operation.

[0172] During implementation, the alarm may be an audible and visual alarm.

[0173] Among them, explosion-proof exhaust fans are fixedly installed on the side walls of the standard meter installation room and the meter under test calibration room respectively, and the start control module of the explosion-proof exhaust fan is connected to the trigger signal output interface of the combustible gas alarm.

[0174] In this way, the explosion-proof exhaust fan can be started immediately when the combustible gas alarm sends a detection signal to quickly discharge the indoor combustible gas to the outside, reduce the concentration of combustible gas, and avoid causing an explosion.

[0175] Among them, the power supply circuits of the high-voltage cabinet and the control cabinet of the actual gas flow high and low temperature verification system are respectively provided with relays and circuit breakers connected to the trigger signal output control of the combustible gas alarm.

[0176] Therefore, when the combustible gas alarm detects a concentration limit alarm, the power supply circuit of the high-voltage cabinet and the control cabinet can be automatically disconnected, effectively avoiding the generation of electric arcs (electric sparks) and effectively avoiding explosions.

[0177] Wherein, the walls, ceiling and floor of the standard meter installation room and the meter under test calibration room respectively have a heat insulation layer; the heat insulation layer is at least one of rock wool, glass wool or aerogel felt.

[0178] During implementation, the thermal insulation layer is a sandwich layer between the wall, the top and the ground.

[0179] The above thermal insulation layer not only has good thermal insulation effect, but also has certain energy absorption, tensile resistance and explosion-proof properties, which can reduce the external impact force caused by the explosion when extreme conditions occur.

[0180] Wherein, a circle of grounding flat iron is buried in the ground around the bottom of each of the standard meter installation room and the meter under test calibration room, and the grounding flat iron is electrically connected to the metal frame in the room and the outer surface of the pipe body in the room through a metal conductor.

[0181] In this way, the metal frames of the standard meter installation room and the meter under test calibration room as well as the pipes in the room can be fully grounded through the grounding flat iron, effectively avoiding the adverse effects caused by lightning strikes or static electricity and better ensuring safety.

[0182] The cooling water tank is a flat rectangular structure as a whole and is integrally covered and fixedly installed on the common outer top surface of the standard meter installation room and the meter under test inspection room.

[0183] During implementation, the side wall of the refrigeration water tank is made of corrosion-resistant thin metal (such as 1.5-3.5mm thick 304 or 316 stainless steel). The outer surface of the refrigeration water tank has a heat insulation layer, and the heat insulation layer is aluminum foil rubber plastic insulation cotton. Aluminum foil rubber plastic insulation cotton not only has good heat insulation and heat preservation effects, but aluminum foil also has radiation protection effects, which better avoids the interference of electromagnetic radiation on the room. At the same time, the aluminum foil rubber plastic insulation cotton itself is flexible and can also absorb energy during explosion impact, which plays a role in reducing the impact force of the explosion and reducing the degree of explosion damage.

[0184] In this way, the cooling water tank will not only not take up additional floor space, reducing the floor space required for arranging the temperature control system; at the same time, it can also make full use of the idle space on the top of the standard meter installation room and the meter under test calibration room to fully expand the capacity of the cooling water tank; after expanding the capacity of the cooling water tank, the water with a larger capacity can use the low-cost electricity at night to cool and store more energy, which can be released during the peak power consumption time during the day (regulating and lowering the actual gas temperature for calibration), helping to reduce electricity costs and calibration expenses.

[0185] In addition, placing the cooling water tank on the common outer top surface of the standard meter installation room and the meter under test calibration room can also absorb the energy of the explosion of combustible gas in extreme cases; after the cooling water tank is damaged by the explosion and a hole is formed, the cooling water in it can flow out of the hole to cool down and extinguish the fire, playing a certain protective role and preventing the fire from spreading.

[0186] The above are only preferred implementations of the present invention. It should be pointed out that a number of modifications and improved technical solutions made by those skilled in the art without departing from the technical solution should also be deemed to fall within the scope of protection required by the claims.

Claims

1. A real gas flow verification process, The method comprises the following steps: The first step is to prepare the real flow gas for calibration; put the meter to be tested into the calibration real gas circulation loop; The second step is to open the test gas circulation loop and allow the gas flow therein to circulate; adjust and stabilize the working temperature, working instantaneous volume flow rate and working pressure of the gas in the test gas circulation loop to preset values; Step 3: Enter the sampling period and continuously collect and store the metering data of the standard meter and the meter under test, and verify the temperature of the gas in the actual gas circulation loop, the instantaneous volume flow rate and the working pressure during the sampling period; Step 4: Calculate and output the calibration data of the meter under test based on the measurement data in step 3.

2. The actual gas flow rate verification process according to claim 1, characterized in that: In the third step, the metering pulse signals generated by the standard meter and the meter under test during the calibration process are independently collected and recorded using a pulse counter after being photoelectrically shaped and amplified.

3. The actual gas flow rate verification process according to claim 1, characterized in that: Repeat steps 1 to 4 to complete the calibration of different working conditions.

4. The actual gas flow rate verification process according to claim 1, characterized in that: This process utilizes a real gas flow high and low temperature calibration system.

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