Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
As shown in FIG. 1, the real-air flow high-low temperature verification system comprises a verification real-air circulation loop, a temperature regulating system and a verification control system, wherein the verification real-air circulation loop is connected with a real-air supply system, a etalon module, a verification module and a flow driving regulation and control module in series through pipeline sealing;
The real gas supply system is used for continuously outputting the verification gas used in the verification process, and an electric control valve is arranged on a gas pipeline at the output end;
the verification module comprises at least one checked station which is connected in series;
the flow driving regulation and control module comprises a fan which is connected in series in a verification real-gas circulation loop in a sealing way and can regulate speed, and a flow regulating sonic nozzle group, wherein the fan is a circulation fan, a centrifugal fan or an axial flow fan;
The temperature control module is used for regulating and controlling the temperature of the gas medium conveyed in the verification real-gas circulation loop and the ambient temperature where the verification module and the standard module are positioned;
The verification control system is used for controlling the real air supply system, the flow driving regulation and control module and the temperature control module.
The inspected station comprises a flowmeter installation station or/and at least two inspected meter installation stations connected in series, the inspected flowmeter is a gas turbine flowmeter or a gas roots flowmeter, an ultrasonic flowmeter and other gas flowmeter types, and the inspected meters can be ultrasonic gas meters, MEMS thermal gas meters, membrane gas meters and other gas meters. The installation station of the tested flowmeter or/and the gas meter comprises a flange interface test tool and a threaded interface test tool, the flange interface test tool and the threaded interface test tool can be used for blending according to flowmeters with different calibers, different lengths and different interface intervals of different threaded specifications, front and rear straight pipe sections are arranged in a matched mode, and independent pressure and temperature measurement sensors are arranged on each standard meter and each tested meter installation station.
In practice, the system standard meter is preferably a serial high-precision three-rotor positive displacement flowmeter, for example, the standard meter can adopt a Rogowski flowmeter with the accuracy level less than or equal to 0.2 level.
When the method is implemented, on the basis of the high-precision three-rotor positive displacement flowmeter, critical flow Venturi sonic nozzles with various flow specifications can be added, so that the flow control points of the standard device module are supplemented.
In the implementation, in order to realize a large flow range of (0.016-160) m3/h, the fan can adopt a high-power high-voltage variable-frequency circulating fan, the circulating fan is in an air cooling design, the flow can be quickly and automatically regulated within the range of (0.016-160) m3/h according to verification requirements through comprehensive regulation of the frequency converter and the flow regulator, the simulation of working conditions in the large flow range is better met, and the universality of the real-air flow high-low-temperature verification system is improved.
Compared with the prior art, the real air flow high-low temperature verification system of the technical scheme has the advantages that:
1. The real gas supply system can output any single component (methane, hydrogen and the like are used as mediums) or mixed components (methane, propane, hydrogen or nitrogen, liquefied petroleum gas and the like), and more truly simulates working condition scenes (scenes of different components, different temperatures, different pressures, different instantaneous flow and the like) of the gas meter when the gas meter is actually used in the future or in the future, so that the verification result is more objective and accurate.
2. The fan in the flow driving regulation and control module can realize stepless speed regulation and has a larger speed regulation range, so that the flow regulation in a larger range can be realized in the circulating flow channel, the application range of calibrating different flow meters/gas meters is enlarged, and the practicability is improved.
3. The temperature control module can regulate and control the temperature of the real air, so that the temperature conditions of different working conditions can be better reproduced, and the verification requirements of temperature environments of different regions can be more comprehensively simulated.
4. The real gas supply system has the functions of gas vacuumizing, gas circulation, gas replacement and gas emptying.
5. The real gas supply system adopts the combination of the standard flowmeter with high accuracy level and the critical flow Venturi sonic nozzle, and can meet the verification range requirements of micro flow and normal flow.
6. The real gas supply system adopts the measurement performance test under the special working conditions of high and low temperature, non-ideal flow field and the like to obtain the commonality of the measurement performance of the flow meter (gas meter) under the natural gas real flow and complex working conditions, constructs a measurement performance evaluation model, and constructs a compensation mechanism and a self-adaptive correction model of the flow meter under the conditions of different temperature fields and non-ideal flow fields.
7. In the gas industry, a metering performance testing device for a flow meter (gas metering instrument) with natural gas actual flow and high and low temperature working conditions as cores is developed for the first time, so that the rapid temperature control of fluid is realized, and the detection requirement of the flow meter (gas metering instrument) under the complex working conditions is met.
In implementation, the following electrical signals are collected and processed respectively:
and the verification control signals are that various control signals in the verification system enter the CPU card through AI/AO/DI/DO and other card parts, the CPU card communicates with a verification computer through a bus protocol, and verification software sends out verification and control instructions.
The temperature/pressure/humidity/liquid level/flow meter signals (usually RS485 or HART signals) are collected, all measuring standard lobby flow meters, pressure, temperature and other measuring meters at the detected flowmeter/gas meter, and measuring meters in a safety system and a circulating cooling system directly enter a verification system collecting card, and verification software reads the signals in real time through digital communication.
The shooting and the light pulse signals are collected through independent modules.
And selecting a process pipeline, namely communicating the current set flow point and flow path selection information to a control system through a Modbus protocol by verification software, and automatically opening a switch valve on a standard meter flow path required to be opened by the flow point in the verification plan by the control system.
And (3) temperature control, namely dynamically adjusting the temperature of the verification medium to a set temperature by a temperature adjusting system, wherein a verification operator only needs to set the target temperature of the verification in a verification plan, and manual interference is not needed under the normal condition.
And (3) pressure control, namely manually adjusting the pressure in the loop to the detection pressure.
And (3) flow control, namely after verification is started, automatically adjusting the flow of verification gas in the loop to the flow required by verification by the verification system through the frequency converter and the flow regulator.
In practice, the verification real-gas circulation loop can be provided with various process pipelines, and each process pipeline can be closed or opened by controlling the electric control valve at the head and the tail of the related process pipeline. Parameters displayed by each process line include standard instantaneous volumetric flow, operating pressure and operating temperature, flow/pressure/temperature/humidity meter status, and individual valve status.
The temperature regulating system of the real-air flow high-low temperature verification system comprises a heat exchange module and a refrigerating and heating unit;
The heat exchange module is internally provided with a sealed containing cavity for loading refrigerating/heating media, and a section of real air conveying pipe for heat exchange made of a heat conducting metal material penetrates through the sealed containing cavity in a verification real air circulation loop of the real air flow high-low temperature verification system in a sealing way;
The refrigerating and heating unit is used for circularly supplying refrigerating/heating media into the sealed containing cavity of the heat exchange module, so that the heat exchange module can realize heat exchange with the real air conveyed in the verification real air circulation loop of the real air flow high-low temperature verification system to realize temperature regulation.
In practice, the thermally conductive metallic material is stainless steel (304 or 316) or red copper.
Compared with the prior art, the temperature regulating system of the real air flow high-low temperature verification system in the technical scheme has the advantages that:
1. the system has simple structure, and is convenient for arranging and installing one or more sets in the verification real-gas circulation loop of the real-gas flow high-low temperature verification system to realize the one-stage or multi-stage temperature stable regulation and control requirement.
2. Because each of the installation stations of the detected flowmeter and the installation stations of the detected meter is provided with an independent temperature measuring sensor, the data of each temperature measuring sensor can be collected to serve as a feedback signal, and the feedback signal is used for accurately regulating and controlling the gas temperature in the real gas circulation loop, so that the real simulation of various real gas temperature working conditions is realized.
Wherein the refrigerating/heating medium is water;
the refrigerating and heating unit comprises a refrigerating and heating module, a refrigerating water tank and a heating water tank;
The refrigerating and heating module comprises a compressor, a condenser, a drying filter, a capillary tube and an evaporator, wherein an air outlet pipe interface of the compressor is communicated with an input end of the condenser in a sealing way, an output end of the condenser is communicated with one end of the drying filter in a sealing way, the other end of the drying filter is communicated with one end of the capillary tube in a sealing way, the other end of the capillary tube is communicated with one end of the evaporator in a sealing way, and the other end of the evaporator is communicated with an air return pipe interface of the compressor;
The evaporator is integrally and fixedly arranged in the refrigerating water tank, and the condenser is integrally and fixedly arranged in the heating water tank.
In practice, the refrigerant may be any one of R22, R410a or R600 a.
The working principle of the refrigerating and heating module in the technical scheme is as follows:
The liquid-state refrigerant entering through the air return pipe is processed into a high-temperature high-pressure gas state by the compressor, the gas state is output from an air outlet pipe interface of the compressor and enters the evaporator, the refrigerant in the evaporator releases heat and is changed into the gas state from the liquid state, the gas-state refrigerant is compressed into the liquid state again through the capillary after passing through the drying filter, the liquid-state refrigerant expands in the evaporator to absorb heat and refrigerates and is changed into the gas state from the liquid state, and the gas-state refrigerant finally reenters the air return end of the compressor.
The technical proposal adopts water as refrigeration/heating medium and has the advantages that:
1. the water has low price and low use cost, the specific heat capacity of the water is large (4.2 multiplied by 103J/(kg DEG C)), the temperature uniformity is good, and the noise is lower when the circulating water pump is combined to operate, so that the working environment is more friendly.
2. The water has a wide temperature regulating range (-5 to 100 ℃) and can meet the requirement of the gas temperature regulating range.
3. The thermal stability of water is better, and temperature variation is more steady, more does benefit to realization accurate temperature regulation and heat preservation.
The heat exchange modules are arranged on the real-gas input side and the real-gas output side of the inspected meter in the real-gas flow high-low temperature verification system;
the heat exchange module comprises a heat exchange container and a circulating water pump, wherein the sealed cavity is arranged in the heat exchange container;
The output port of the circulating water pump is communicated with the circulating water inlet in a sealing way, and the input port and the circulating water outlet of the circulating water pump are communicated with the refrigerating water tank and the heating water tank in a sealing way through a three-way valve respectively.
Because the real air flow high-low temperature verification system is provided with the verification real air circulation loop, the real air input side and the output side of the standard meter and the real air input side and the output side of the inspected meter in the real air flow high-low temperature verification system are respectively provided with the heat exchange module, the heat exchange module at the input side can effectively regulate and control the real air temperature entering the standard meter and the inspected meter, and the heat exchange module at the output side can effectively regulate and control and maintain the stability of the real air flow in the verification real air circulation loop, so that the accurate temperature control is better realized.
In the technical scheme, the circulating water pump adopts the variable frequency controller for the water pump to carry out variable frequency control on the rotating speed of the water pump so as to improve the regulation speed and the constant temperature precision, and meanwhile, the circulating water pump also comprises a refrigerating and heating controller, wherein the refrigerating and heating controller is in signal connection with a temperature measurement sensor which is arranged on an input side pipeline of each detected flowmeter installation station and each detected flowmeter installation station in the real air flow high-low temperature verification system, and the refrigerating and heating controller is also in control connection with a compressor, the variable frequency controller for the water pump and a three-way valve so as to realize the accurate temperature control of real air.
The temperature regulating system further comprises a standard meter installation chamber and a tested meter verification chamber, wherein the standard meter installation chamber and the tested meter verification chamber are independent of each other, doors allowing personnel to enter and exit are arranged in the standard meter installation chamber, a pipeline section for installing a standard meter and the heat exchange module are arranged in the standard meter installation chamber, and a pipeline section for installing a tested meter and the heat exchange module are arranged in the tested meter verification chamber.
After the standard meter installation chamber and the inspected meter verification chamber which are independent and provided with the air conditioner and the door structure are arranged, the indoor air environment can be regulated by the air conditioner, so that the temperature of the indoor air is close to the temperature of the gas in the verification real air circulation loop, the temperature difference between the air outside the verification real air circulation loop and the real air inside the verification real air circulation loop is further reduced, and the accurate control of the temperature of the gas in the verification real air circulation loop is further realized.
When in implementation, the refrigerating water tank can adopt a tank body with a heat preservation and insulation layer at the outer side.
A real-air flow assay control system, comprising:
The host module comprises a processor, a memory electrically connected with a corresponding interface on the processor, an input/output module, a power module and a communication module;
The parameter acquisition module comprises an actual gas parameter acquisition device, a pulse isolation amplifier and a pulse/time measurement module, wherein the actual gas parameter acquisition device is used for acquiring the temperature, the pressure and the instantaneous flow of the actual gas in the actual gas circulation loop, and the output side is in signal connection with the input/output module;
The electric control executing mechanism comprises a relay, an electric control valve, a flow driving regulation and control module and a temperature control module, wherein the control side interface of the relay is in signal connection with the corresponding interface on the input/output module.
Compared with the prior art, the technical scheme real-air flow verification control system has the advantages that:
1. the whole system adopts a modularized design, and is easier to be distributed, maintained and used.
2. The pulse signals collected by verification are accurate, so that higher flow measurement precision can be achieved, and verification and control precision is ensured.
In implementation, the pulse/time measurement module adopts iTS-PD high-precision multichannel pulse/time detection units, the frequency acquisition range of the detection units can cover (0-10) kHz, the acquisition precision is better than 0.001%, up to 8 paths of standard meters and instantaneous signals of the detected meter can be measured simultaneously, and each standard flowmeter is provided with an independent measurement channel, so that the detection of up to 32 channels is supported at most.
The pulse signal acquisition process in the technical scheme is that pulse signals of a standard roots flowmeter and a detected flowmeter enter a pulse/frequency/time acquisition system after photoelectric shaping and amplification. The pulse signals of the checked table and the standard table are respectively and continuously input into the pulse counter and continuously read by the host module. The pulse data acquisition module achieves higher flow measurement precision through a double timing processing technology (a time period is measured firstly, and then high-precision timing processing is carried out in the time period to obtain higher timing precision), so that the precision of verification and control is ensured.
The flow driving regulation and control module comprises a fan which is connected in series and sealed in an air duct in a verification real-air circulation loop and can regulate speed, and the fan is a circulation fan, a centrifugal fan or an axial flow fan;
The temperature control module is used for regulating and controlling the temperature of the gas medium conveyed in the verification real-gas circulation loop and the ambient temperature of the verification module and the standard device module.
The fan in the flow driving regulation and control module can realize stepless speed regulation and has a larger speed regulation range, so that the flow regulation in a larger range can be realized in the circulating flow channel, the application range of calibrating different flow meters/gas meters is enlarged, and the practicability is improved.
The temperature control module can regulate and control the temperature of the real air, so that the temperature of different working conditions can be better reproduced, and the verification requirements of the working conditions of different temperatures can be more comprehensively met.
The real-air flow verification control system further comprises a control chamber, wherein the control chamber is integrally of a box type structure and is provided with 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 chamber, and the host module is arranged in the control chamber.
The arrangement of the control room enables operators to independently operate in the control room, effectively avoids the common space with the real air circulation loop for real air verification, and effectively reduces the harm of noise and air environment to human bodies.
The interlayer of the top wall and the surrounding side walls of the control room are provided with heat insulation layers, and the outer side faces of the control room are made of hard metal.
In practice, the hard metal may be high carbon steel or stainless steel.
Thus, the side wall of the control chamber has higher strength and higher explosion-proof performance.
The ground around the bottom of the control room is buried with a circle of grounding flat iron, and the grounding flat iron is electrically connected with the metal frame structure of the control room through a metal conductor.
Therefore, the metal frame of the control room can be fully grounded through the grounding flat iron, adverse effects caused by lightning stroke or static electricity are effectively avoided, and safety is better ensured.
As shown in fig. 1 to 4, the real gas supply system includes a pure gas module, a gas mixing module, and a component analysis module;
The pure gas module is provided with a plurality of pure gas output interfaces which are used for outputting combustible gas or/and non-combustible gas and can be opened and closed;
The gas mixing module comprises a gas storage tank which is communicated with each pure gas output interface in a sealing way, the gas storage tank is also provided with a gas output interface provided with a control valve and a one-way valve, and the gas output interface is used for being connected into a verification gas circulation loop through a tee joint;
The component analysis module comprises an opening and closing valve, a pressure reducing valve, a one-way valve and a gas chromatograph, wherein a component detection interface of the solid gas storage tank is communicated with a gas detection interface of the gas chromatograph in a sealing way after being communicated with the opening and closing valve, the pressure reducing valve and the one-way valve in a sealing way sequentially through a pressure-proof pipe.
Compared with the prior art, the technical scheme has the advantages that:
The system is reasonable in composition, the component analysis module can be used for accurately detecting the component of the mixed gas, and then the component of the real gas can be flexibly configured according to the verification working condition, so that the system can simulate the working condition more truly, the verification system can be helped to acquire verification data more truly and valuable, the correction accuracy is improved, and the metering accuracy is improved.
In the implementation, the gas chromatograph mainly comprises an online type and an offline type, and because the verification real gas circulation loop uses a high-pressure gas cylinder group for gas supply, the gas components are relatively single, the offline chromatograph is adopted.
The non-combustible gas is at least one of air, nitrogen or carbon dioxide.
In practice, the non-combustible gas sources may each originate from a corresponding medium or high pressure gas cylinder.
When the combustible gas is natural gas, the corresponding output interface is an output interface of a gas pressure regulating box.
The gas pressure regulating box can regulate the higher pressure gas conveyed by the upstream pipeline to a lower and stable pressure suitable for downstream user equipment.
When the combustible gas is hydrogen, the output interface of the corresponding hydrogen is a medium-pressure hydrogen cylinder or a high-pressure hydrogen cylinder.
Medium pressure hydrogen cylinders (pressure between 10-30 MPa) and high pressure hydrogen cylinders (pressure greater than 30 MPa).
The pure gas module and the mixed gas module are open-air cloth and are integrally and fixedly arranged at one end of the long-strip-shaped skid-mounted base in the length direction, a control chamber is arranged at the other end of the skid-mounted base in the length direction, and a standard meter installation chamber and a meter verification chamber to be detected are arranged in the middle of the skid-mounted base in the length direction.
In this way, the real air supply system can be far away from the control room, and the safety of the control room in emergency is improved.
The safety system of the real-air flow high-low temperature verification system comprises a standard meter installation chamber and a detected meter verification chamber which are independent from each other, are provided with doors allowing personnel to enter and exit, are respectively provided with an air conditioner, a pipeline section for installing a standard meter is arranged in the standard meter installation chamber, a pipeline section for installing a detected meter is arranged in the detected meter verification chamber, and a combustible gas sensor and an alarm are fixedly arranged in the standard meter installation chamber and the detected meter verification chamber.
Compared with the prior art, the safety system of the real-air flow high-low temperature verification system has the advantages that:
1. the standard meter and the inspected meter in the real air flow high-low temperature verification system are installed in two independent rooms, so that space isolation is realized, the influence on equipment in the whole space caused by gas leakage in a single place is avoided, and the safety is improved.
2. The standard meter and the detected meter are arranged in two independent rooms, the relative space between the two independent rooms is smaller, the concentration of the standard meter and the detected meter is higher once slight leakage occurs, the standard meter and the detected meter are more easily detected by an indoor combustible gas sensor and an alarm is triggered to give an alarm, and the safe operation level is improved.
In the implementation, the alarm can adopt an audible and visual alarm.
The side walls of the inside of the standard meter installation chamber and the side walls of the detected meter verification chamber are fixedly provided with explosion-proof exhaust fans, and a starting control module of the explosion-proof exhaust fans is connected with a triggering signal output interface of the combustible gas alarm in a control mode.
Therefore, the explosion-proof exhaust fan can be started immediately when the flammable gas alarm sends out a detection signal to rapidly exhaust indoor flammable gas out of the room, so that the concentration of the flammable gas is reduced, and explosion is avoided.
The power supply loops of the strong current cabinet and the control cabinet of the real-gas flow high-low temperature verification system are respectively provided with a relay and a breaker which are connected with the triggering signal output of the combustible gas alarm in a control way.
Therefore, the concentration limit value is detected to alarm at the combustible gas alarm, the power supply loop of the strong current cabinet and the control cabinet can be automatically disconnected, the generation of electric arcs (electric sparks) is effectively avoided, and the explosion is effectively avoided.
The wall, the top and the ground of each of the standard meter installation chamber and the inspected meter verification chamber are provided with heat insulation layers, and the heat insulation layers are at least one of rock wool, glass wool or aerogel felt.
When in use, the heat insulation layer is an interlayer of the wall, the roof and the ground.
The heat insulation layer has good heat insulation effect, has certain energy absorption, tensile resistance and explosion prevention characteristics, and can reduce external impact force caused by explosion when extreme conditions occur.
The ground of the periphery of the bottoms of the standard meter installation chamber and the inspected meter verification chamber are buried with a circle of ground flat iron, and the ground flat iron is electrically connected with the indoor metal frame and the indoor outer surface of the pipe body through metal conductors.
Therefore, the metal frames of the standard meter installation chamber and the inspected meter verification chamber and the pipe body in the chamber can be fully grounded through the grounding flat iron, adverse effects caused by lightning stroke or static electricity are effectively avoided, and safety is better ensured.
The whole refrigerating water tank is of a flat rectangular body type structure and is integrally covered and fixedly arranged on the outer top surface of the standard meter installation chamber and the outer top surface of the inspected meter verification chamber.
In practice, the side walls of the refrigeration water tank are made of corrosion-resistant thin metal (such as 304 or 316 stainless steel with the thickness of 1.5-3.5 mm). The external surface of the refrigeration water tank is provided with a heat insulation layer, and the heat insulation layer is aluminum foil rubber plastic heat insulation cotton. The aluminum foil rubber plastic heat preservation cotton not only has good heat insulation and preservation effect, but also has radiation protection effect, and the interference influence of electromagnetic radiation on the indoor is better avoided. Meanwhile, the aluminum foil rubber plastic heat-insulating cotton has flexibility, and can absorb energy during explosion impact, so that the effect of reducing the explosion impact force and the explosion damage degree are achieved.
The refrigerating water tank not only does not occupy extra occupied area and reduces occupied area required by arranging a temperature regulating system, but also can fully utilize the idle space at the top of the standard meter installation room and the detected meter verification room to fully expand the volume of the refrigerating water tank, after the volume of the refrigerating water tank is expanded, more water with higher capacity can utilize low-peak electricity with lower unit price at night to refrigerate and store more energy, and the energy can be released (the real temperature is regulated and controlled to be reduced for verification) in peak electricity utilization time in daytime, thereby helping to reduce electricity utilization cost and verification expense.
In addition, the refrigerating water tank is arranged on the outer top surface of the standard meter installation chamber and the inspected meter verification chamber, can absorb the energy of the explosion of the combustible gas under extreme conditions, and can cool and extinguish the fire by cooling water flowing out of the holes after the holes are formed by the explosion of the refrigerating water tank, so that a certain protection effect is achieved, and the expansion of fire is avoided.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and improvements made by those skilled in the art without departing from the present technical solution shall be considered as falling within the scope of the claims.