A V-cone household natural gas flow calculation method and device

Abstract

The embodiment of the present invention provides a method and device for calculating the flow rate of a V-cone household natural gas, the method comprising: obtaining standard data of natural gas under standard reference conditions; determining a first relationship between the volume flow rate of natural gas under standard reference conditions and the standard orifice differential pressure range according to the volume flow calculation formula of the V-cone flowmeter and the standard data; determining a second relationship between the volume flow rate of natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter according to the preset parameter information of the V-cone flowmeter and the first relationship; determining the differential pressure range of the V-cone flowmeter using the chord intercept method according to the second relationship and the preset parameter value; determining the volume flow rate of natural gas under the V-cone flowmeter according to the second relationship and the differential pressure range of the V-cone flowmeter. By implementing the present invention, the calculation of household natural gas flow based on the V-cone flowmeter is realized, providing an accurate data basis for the application of the V-cone flowmeter to household gas meters.

Description

Technical Field

[0001] The invention relates to the field of gas flow detection, and in particular to a V-cone household natural gas flow calculation method and device. Background Art

[0002] The V-cone flowmeter uses a V-shaped cone coaxially installed in the pipeline to gradually throttle and shrink the fluid to the inner wall of the pipeline, and measures the flow rate by measuring the differential pressure before and after the V-shaped inner cone. At present, traditional V-cone flowmeters are widely used in the field of industrial natural gas. Due to the limitations of the traditional V-cone flowmeter itself, they cannot be well applied in the field. Because the flow rate of natural gas pipelines in the civil field is small and the static pressure of the pipeline is low. Due to the limitations of the differential pressure sensor, the traditional V-cone flowmeter cannot measure smaller differential pressure changes, so it cannot adapt to this scenario well. Later, people used MEMS sensors to replace traditional differential pressure sensors, which effectively solved the problems of traditional V-cone flowmeters in small pipeline flow and low pipeline static pressure. However, there is currently no effective calculation method for measuring the flow rate of domestic natural gas using V-cone flowmeters based on MEMS sensors. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defect in the prior art that there is a lack of a V-cone flow meter based on a MEMS sensor to measure the flow calculation method of domestic natural gas, thereby providing a V-cone domestic natural gas flow calculation method and device.

[0004] An embodiment of the present invention provides a V-cone household natural gas flow calculation method, comprising: obtaining standard data of natural gas under standard reference conditions; determining a first relationship between the volume flow of natural gas under standard reference conditions and a standard orifice differential pressure range according to a volume flow calculation formula of a V-cone flowmeter and the standard data; determining a second relationship between the volume flow of the natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter according to preset parameter information of the V-cone flowmeter and the first relationship; determining the differential pressure range of the V-cone flowmeter using a chord intercept method according to the second relationship and preset parameter values; and determining the volume flow of the natural gas under the V-cone flowmeter according to the second relationship and the differential pressure range of the V-cone flowmeter.

[0005] Optionally, a first relationship between the volume flow rate of the natural gas under standard reference conditions and the standard orifice differential pressure range is obtained according to the following formula:

[0006]

[0007] Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn represents the metering coefficient of volume flow, C represents the outflow coefficient, E represents the asymptotic velocity coefficient, d represents the opening diameter, and F represents theG represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow at the pressure-taking hole on the upstream side of the orifice plate, and △p represents the differential pressure range of the airflow passing through the standard orifice plate.

[0008] Optionally, the second relationship between the volume flow rate of the natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter is obtained according to the following formula:

[0009]

[0010] Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn represents the metering coefficient of volume flow, C represents the discharge coefficient, E represents the asymptotic velocity coefficient, β V Indicates the equivalent diameter ratio of the V-cone throttling device, D represents the inner diameter of the pipe, F G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow through the pressure-taking hole on the upstream side of the orifice plate, △p K Indicates the differential pressure range of air flowing through the V-cone flowmeter.

[0011] Optionally, the preset parameter value includes a first parameter value and a second parameter value, and the chord intercept method is used to determine the differential pressure range of the V-cone flowmeter based on the second relationship and the preset parameter value, including: obtaining a first difference based on the second relationship and the first parameter value; obtaining a second difference based on the second relationship and the second parameter value; and determining the differential pressure range of the V-cone flowmeter based on the chord intercept method based on a preset standard range, the first parameter value, the second parameter value, the first difference, and the second difference.

[0012] An embodiment of the present invention also provides a V-cone household natural gas flow calculation device, comprising: a standard data acquisition module, used to obtain standard data of natural gas under standard reference conditions; a first relationship determination module, used to determine the first relationship between the volume flow rate of the natural gas under standard reference conditions and the standard orifice differential pressure range according to the volume flow calculation formula of the V-cone flowmeter and the standard data; a second relationship determination module, used to determine the second relationship between the volume flow rate of the natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter according to preset parameter information of the V-cone flowmeter and the first relationship; a differential pressure range determination module, used to determine the differential pressure range of the V-cone flowmeter using the chord intercept method according to the second relationship and preset parameter values; a volume flow calculation module, used to determine the volume flow rate of the natural gas under the V-cone flowmeter according to the second relationship and the differential pressure range of the V-cone flowmeter.

[0013] Optionally, the first relationship generating module obtains the first relationship between the volume flow rate of the natural gas under standard reference conditions and the standard orifice differential pressure range according to the following formula:

[0014]

[0015] Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn represents the metering coefficient of volume flow, C represents the outflow coefficient, E represents the asymptotic velocity coefficient, d represents the opening diameter, and F represents the G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow at the pressure-taking hole on the upstream side of the orifice plate, and △p represents the differential pressure range of the airflow passing through the standard orifice plate.

[0016] Optionally, the second relationship generating module obtains the second relationship between the volume flow rate of the natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter according to the following formula:

[0017]

[0018] Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn represents the metering coefficient of volume flow, C represents the discharge coefficient, E represents the asymptotic velocity coefficient, β V Indicates the equivalent diameter ratio of the V-cone throttling device, D represents the inner diameter of the pipe, F G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow through the pressure-taking hole on the upstream side of the orifice plate, △p K Indicates the differential pressure range of air flowing through the V-cone flowmeter.

[0019] Optionally, the preset parameter value includes a first parameter value and a second parameter value, and the differential pressure range determination module includes: a first difference calculation submodule, used to obtain a first difference based on the second relationship and the first parameter value; a second difference calculation submodule, used to obtain a second difference based on the second relationship and the second parameter value; a differential pressure range determination submodule, used to determine the differential pressure range of the V-cone flowmeter using the chord intercept method based on a preset standard range, the first parameter value, the second parameter value, the first difference, and the second difference.

[0020] The embodiment of the present invention further provides a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to enable the computer to execute the above-mentioned V-cone household natural gas flow calculation method.

[0021] An embodiment of the present invention also provides a computer device, comprising: at least one processor; and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the above-mentioned V-cone household natural gas flow calculation method.

[0022] The technical solution of the present invention has the following advantages:

[0023] The embodiment of the present invention provides a method for calculating the flow rate of a V-cone household natural gas, including: obtaining standard data of natural gas under standard reference conditions, and determining the first relationship between the volume flow rate of natural gas under standard reference conditions and the standard orifice differential pressure range in combination with the volume flow formula of the V-cone flowmeter, and determining the second relationship between the volume flow rate of natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter in combination with the parameter information of the preset V-cone flowmeter, and determining the differential pressure range of the V-cone flowmeter by using the chord intercept method, and then determining the volume flow rate of natural gas under the V-cone flowmeter in combination with the second relationship. Thus, by combining the standard data of natural gas and the characteristics of the V-cone flowmeter itself, the calculation of the flow rate of household natural gas based on the V-cone flowmeter is realized, providing an accurate data basis for the application of the V-cone flowmeter to household gas meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 Flow chart of the V-cone household natural gas flow calculation method in an embodiment of the present invention;

[0026] Figure 2 A specific flow chart of determining the differential pressure range of a V-cone flowmeter using the chord intercept method according to the second relationship and the preset parameter value in an embodiment of the present invention;

[0027] Figure 3 Schematic diagram of the structure of a V-cone household natural gas flow calculation device in an embodiment of the present invention;

[0028] Figure 4 Schematic diagram of the structure of the differential pressure range determination module in an embodiment of the present invention;

[0029] Figure 5 Schematic diagram of the structure of a computer device in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that the terms “first”, “second” and “third” are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0032] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] Example 1

[0034] The embodiment of the present invention provides a V-cone household natural gas flow calculation method, such as Figure 1 As shown, the V-cone household natural gas flow calculation method includes:

[0035] Step S1: Obtain standard data of natural gas under standard reference conditions. Specifically, the standard data can be obtained according to "Calculation Method of Natural Gas Density and Fluid Coefficient", national standards, and petroleum and natural gas industry standards.

[0036] Step S2: Determine the first relationship between the volume flow rate of natural gas under standard reference conditions and the standard orifice differential pressure range according to the volume flow calculation formula of the V-cone flowmeter and standard data. Specifically, the standard orifice differential pressure range is the pressure difference generated when the natural gas gas flows through the standard orifice.

[0037] Step S3: According to the preset parameter information of the V-cone flowmeter and the first relationship, determine the second relationship between the volume flow rate of natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter. Specifically, the second relationship between the volume flow rate of natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter is the pressure difference before and after the inner cone when the natural gas gas flows through the V-cone flow tube.

[0038] Step S4: According to the second relationship and the preset parameter value, the differential pressure range of the V-cone flowmeter is determined by using the chord intercept method. Since the differential pressure ranges of different V-cone flowmeters are different, it is necessary to determine the differential pressure range of the V-cone flowmeter for a specific application, so as to calculate the volume flow rate of natural gas under the V-cone flowmeter.

[0039] Step S5: Determine the volume flow rate of natural gas under the V-cone flowmeter according to the second relationship and the differential pressure range of the V-cone flowmeter. The volume flow rate is the volume flow rate flowing through the domestic natural gas pipeline.

[0040] Through the above steps S1 to S5, the V-cone household natural gas flow calculation method of the embodiment of the present invention realizes the calculation of household natural gas flow based on the V-cone flowmeter by combining the standard data of natural gas and the characteristics of the V-cone flowmeter itself, providing an accurate data basis for the application of the V-cone flowmeter in household gas meters.

[0041] The V-cone household natural gas flow calculation method according to an embodiment of the present invention will be described in detail below in conjunction with specific application examples.

[0042] In practical applications, the basic principle of V-cone flowmeters is still to follow the Bernoulli equation and the fluid flow continuity equation. The volume flow calculation formula of the V-cone differential pressure flowmeter is:

[0043]

[0044] Among them, q V represents the volume flow rate of natural gas, C represents the outflow coefficient, β represents the equivalent diameter ratio, ε represents the expansion coefficient, d represents the opening diameter, △p represents the differential pressure range of the gas flow through the standard orifice plate, ρ1 represents the density of the natural gas at the upstream pressure hole under operating conditions, ρ n Indicates the density of natural gas under standard reference conditions.

[0045] In practical applications, the above step S1 obtains standard data of natural gas under standard reference conditions. The standard data is obtained according to the "Calculation Method of Natural Gas Density and Fluid Coefficient", national standards, and petroleum and natural gas industry standards. The practical formula of natural gas under operating conditions is:

[0046]

[0047] Where ρ1 represents the density of natural gas at the upstream pressure tapping hole under operating conditions, M a represents the molar mass of dry air, which is 28.9626 kg / kmol; M represents the molar mass of natural gas, which is kg / kmol; R represents the universal gas constant, which is 0.00831451 [MPa·m 3 / (kmol·K)]; Z a It represents the compressibility factor of dry air under standard reference conditions, and its value is 0.99963; Z nrepresents the compression factor of natural gas under standard reference conditions; P1 represents the absolute pressure of the upstream pressure tapping hole of natural gas under operating conditions, MPa; T1 represents the thermodynamic temperature of natural gas under operating conditions, K; Z1 represents the compression factor of natural gas under operating conditions; G r Indicates the true relative density of natural gas.

[0048] The practical formula for natural gas under standard reference conditions is:

[0049]

[0050] Among them, ρ n Indicates the density of natural gas under standard reference conditions, M a represents the molar mass of dry air, which is 28.9626 kg / kmol; M represents the molar mass of natural gas, which is kg / kmol; R represents the universal gas constant, which is 0.00831451 [MPa·m 3 / (kmol·K)]; Z a It represents the compressibility factor of dry air under standard reference conditions, and its value is 0.99963; Z n Indicates the compressibility factor of natural gas under standard reference conditions; P n It indicates the absolute pressure of the upstream pressure tapping hole of natural gas under standard reference conditions, MPa; T n Indicates the thermodynamic temperature of natural gas flow under operating conditions, K; Z n Indicates the compressibility factor of natural gas under standard reference conditions; G r Indicates the true relative density of natural gas.

[0051] In a preferred embodiment, the above step S2 determines the first relationship between the volume flow rate of natural gas under standard reference conditions and the standard orifice differential pressure range according to the volume flow calculation formula of the V-cone flowmeter and the standard data. In practical applications, the first relationship between the volume flow rate of natural gas under standard reference conditions and the standard orifice differential pressure range can be determined by combining and arranging the above formula (1), formula (2) and formula (3) as follows:

[0052]

[0053] Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn Indicates the metering coefficient of volume flow, which depends on the unit of measurement used, for example: volume flow per second (m 3 / s) Measuring coefficient: A Vns =3.1795×10 -6 , hourly volume flow rate (m 3 / s) Measuring coefficient: A Vnh =0.011446, daily volume flow rate (m 3 / s) Measuring coefficient: A Vns =0.27471, C represents the outflow coefficient, E represents the asymptotic velocity coefficient, d represents the opening diameter, F G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow at the pressure-taking hole on the upstream side of the orifice plate, and △p represents the differential pressure range of the airflow passing through the standard orifice plate.

[0054] In practical applications, the flow area formula of the above standard orifice plate is:

[0055]

[0056] Wherein, S1 represents the flow area of ​​the standard orifice plate, and d represents the diameter of the standard orifice plate.

[0057] In practical applications, the equivalent diameter ratio of the above standard orifice plate is:

[0058] β=d / D (6)

[0059] Among them, β represents the equivalent diameter ratio, d represents the standard orifice plate diameter, and D represents the inner diameter of the pipe.

[0060] In practical applications, it is assumed that the maximum cross-sectional diameter of the cone of the V-cone flowmeter in the embodiment of the present invention is d V , then the flow area of ​​the cone is:

[0061]

[0062] Among them, S1 represents the flow area of ​​the cone, D represents the inner diameter of the pipe, and d V Indicates the maximum cross-sectional diameter of the cone.

[0063] In practical applications, the equivalent diameter ratio calculation formula of the above V-cone flowmeter is:

[0064]

[0065] Among them, β V Indicates the equivalent diameter ratio of the V-cone flowmeter, d V It represents the maximum cross-sectional diameter of the cone, and D represents the inner diameter of the pipe.

[0066] In the above step S3, based on the preset parameter information of the V-cone flowmeter and the first relationship, the second relationship between the volume flow rate of natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter is determined. Specifically, according to the above formula (4), formula (7) and formula (8), the following can be obtained:

[0067]

[0068] Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn It represents the metering coefficient of volume flow, C represents the discharge coefficient, the typical value range of C is 0.75-0.85, which should be determined by actual flow calibration, E represents the asymptotic velocity coefficient, β V Indicates the equivalent diameter ratio of the V-cone throttling device, D represents the inner diameter of the pipe, F G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow through the pressure-taking hole on the upstream side of the orifice plate, △p K Indicates the differential pressure range of air flowing through the V-cone flowmeter.

[0069] In practical applications, the calculation formula of the above-mentioned expandability coefficient ε is:

[0070]

[0071] Among them, ε represents the expansion coefficient, β V Indicates the equivalent diameter ratio of the V-cone throttling device, △p K represents the differential pressure range of the airflow through the V-cone flowmeter, P1 represents the absolute static pressure of the airflow at the pressure-taking hole on the upstream side of the orifice plate, and κ represents the isentropic index of the measured medium (compressible fluid). In practical applications, the dimensions in the above formulas (9) and (10) are consistent with those specified in relevant national standards and natural gas industry standards.

[0072] In a preferred embodiment, if Figure 2 As shown, the above step S4, according to the second relationship and the preset parameter value, uses the chord intercept method to determine the differential pressure range of the V-cone flowmeter, specifically including:

[0073] Step S41: Obtain a first difference value according to the second relationship and the first parameter value.

[0074] In practical applications, flow calculations and design calculations generally cannot be directly substituted into solutions, and iterative calculation methods are often required. K According to the above formula (9), the known quantities are combined on one side of the equation and the unknown quantities are placed on the other side of the equation. During the calculation process, the quantities on the known side are regarded as constants. First, the first parameter value Y1 is substituted into the unknown side, and the first difference δ1 on both sides of the equation is obtained by calculation.

[0075] Step S42: Obtain a second difference value according to the second relationship and the second parameter value. In practical applications, the second parameter value Y2 can be substituted in the same way to obtain a second difference value δ2.

[0076] Step S43: Determine the differential pressure range of the V-cone flowmeter using the chord intercept method according to the preset standard range, the first parameter value, the second parameter value, the first difference, and the second difference.

[0077] In practical applications, the above Y1, Y2, δ1, δ2 are substituted into the linear algorithm until |δ n | is less than a certain specified value. Or the iteration is completed when the successive values ​​of Y and δ are equal to a certain specified accuracy. The calculation formula using the chord intercept method with fast convergence is:

[0078]

[0079] Among them, Y n Indicates the nth parameter value, Y (n-1) The n-1th parameter value, Y (n-2) The n-2th parameter value, δ (n-1) The n-1th difference, δ (n-2) The n-2th difference.

[0080] In practical applications, the first assumed value of ε is assuming ε = 1, when |δ n | Less than 5×10 -10 When , the corresponding △p K This is the differential pressure range of the above-mentioned V-cone flowmeter.

[0081] In practical applications, the above step S5 determines the volume flow rate of natural gas under the V-cone flowmeter according to the second relationship and the differential pressure range of the V-cone flowmeter. The V-cone household natural gas flow rate can be calculated according to the differential pressure range of the V-cone flowmeter and formula (9).

[0082] The V-cone household natural gas flow calculation method according to an embodiment of the present invention will be described in detail below in conjunction with specific experiments.

[0083] Since safe inert gas, such as argon and compressed air, should be used as the test gas source during experimental testing, air is more suitable for experimental testing because the various parameters of air are relatively easy to obtain and the flow rate is guaranteed to a certain extent. The gas source device uses bottled gas, air compressor and high-pressure vortex blower. Compared with bottled gas, the air compressor can provide a steady supply of gas and is more convenient to use, but the flow rate of the air compressor is small and the static pressure is too large, which is inconsistent with the actual situation in the pipeline. The high-pressure vortex blower has a large output flow rate and a small static pressure, which is conducive to the selection of sensors and the calculation of gas flow in the experiment. Therefore, in the embodiment of the present invention, a high-pressure vortex blower is used as the gas source device. The parameters of the high-pressure vortex blower are a maximum wind pressure of 5.5kPa and a flow rate of 30m3 / h; a maximum wind pressure of 7kPa and a flow rate of 50m3 / h.

[0084] Experimental known conditions:

[0085] Measuring tube inner diameter: D = 20mm (DN20, new seamless tube of No. 20 steel);

[0086] Common air flow temperature: t_1 = 25°C

[0087] Air flow rate: q_Vnhmax = 30m^3 / h, 50m^3 / h;

[0088] Common local atmospheric pressure: P_a = 0.0981MPa;

[0089] Gauge pressure value in pipeline: p_1 = 0.0055MPa, 0.007MPa;

[0090] According to GB / T 18603-2014: It belongs to the C-level measurement accuracy requirement, and requires the temperature measurement accuracy to be ≤0.5℃, the pressure measurement accuracy to be ≤0.2%, and the volume flow accuracy to be ≤1.0% under operating conditions.

[0091] Density of compressed air: ρ n =1.2691kg / m 3 ;

[0092] Isentropic index of compressed air at room temperature: κ = 1.40, μ1 = 0.01834 mPa·s;

[0093] Differential compression factor: F Z =1.0001;

[0094] Flow temperature coefficient: F T =0.9916;

[0095] Relative density coefficient: F G =1

[0096] Table 1 shows the inner cone diameter ratio β V, asymptotic velocity coefficient E and differential pressure range △P′ K The experimental value of .

[0097] Table 1 Inner cone diameter ratio and maximum differential pressure (30m 3 / h)

[0098] <![CDATA[β V ]]> D(mm) <![CDATA[d V (mm)]]> E <![CDATA[△P′ K (Well)]]> 0.75 20 13.2288 1.2095 1.4225e+03

[0099] According to the experimental design requirements, experimental devices such as differential pressure sensor, fan, V cone device and pressure gauge were selected. The high-pressure fan provides the gas source, and the valve and pressure gauge are connected through the pipeline. The valve is used to control the static pressure in the pipeline. The gas passes through the V inner cone device. There are two pressure holes at the top of the device to connect the differential pressure sensor. The valve is installed at the back end to adjust the flow rate. The data acquisition card is connected to the differential pressure sensor to obtain the differential pressure value.

[0100] Experimental steps:

[0101] Step 1: Build the experimental device according to the experimental principle design drawing. The differential pressure sensor and the V-cone device pressure pipe are connected with a hose. According to relevant experiments, when installing the VNZ flowmeter at the downstream of various flow-blocking parts, the required straight pipe section is greatly shortened. Generally, a straight pipe section of 0 to 3D is required upstream (when the flowmeter is installed downstream of the valve, 3D is required); a straight pipe section of 0 to 1D is required downstream.

[0102] Step 2: First open the tail valve and adjust the valve near the pressure gauge to adjust the static pressure of the pipeline; fully open the valve and measure the value of the differential pressure sensor at the maximum flow rate; control the tail valve to control the flow rate and observe the change process of the differential pressure value of the differential pressure sensor; close the tail valve to the state close to the differential pressure and measure the differential pressure value.

[0103] Step 3 The data acquisition card collects the data of the differential pressure sensor and records the relevant data under different flow conditions for subsequent experimental analysis and research.

[0104] Through the experiment, the differential pressure sensor changes with the flow rate, and the measured differential pressure results are compared with the calculated results to reversely verify the accuracy of the algorithm. The calculated differential pressure range is correct when the flow rate is known. Similarly, the flow rate obtained by the same calculation method must be accurate when the differential pressure is known.

[0105] After calculation, it is known that the air volume of the fan is 20m 3 / h (due to loss, the actual time is 18.5m 3 / h), open all valves, the voltage detected by the experimental device is 2000mV, according to the characteristics of differential pressure and output voltage of differential pressure sensor, it can be known that the differential pressure at this time is 500Pa; adjust the valve to a state close to the closed state (actually 11.5m 3 / h), the voltage detected by the experimental device is 1389mV, and after conversion, the differential pressure is 194.5Pa; the experiment controls the flow rate by adjusting the size of the valve, and the change in differential pressure increases with the increase of flow rate and decreases with the decrease of flow rate.

[0106] Using the above formula (9), the actual detection flow rate is 18.5m 3 / h calculation, we can calculate △p K =504.3282Pa, according to the actual detection flow rate is 11.5m 3 / h calculation, we can calculate △p K =198.5514Pa. It can be seen that the calculated value is very close to the experimentally measured value. The experiment controls the flow rate by adjusting the size of the valve. The change in differential pressure increases with the increase of flow rate and decreases with the decrease of flow rate.

[0107] The above experiments prove that the actual differential pressure is 18.5m 3 / h calculated to be 504.3282Pa, the sensor measured 500Pa at this time; the actual differential pressure is 11.5m 3 / h is calculated to be 198.5514Pa, and the sensor measures 194.5Pa at this time. The error is very small (the error may come from the difference in the material of the V-cone), which shows that this calculation method is accurate and it is accurate to calculate the gas flow rate using this calculation method.

[0108] Through the above steps S1 to S5, the V-cone household natural gas flow calculation method of the embodiment of the present invention realizes the calculation of household natural gas flow based on the V-cone flowmeter by combining the standard data of natural gas and the characteristics of the V-cone flowmeter itself, providing an accurate data basis for the application of the V-cone flowmeter in household gas meters.

[0109] Example 2

[0110] The embodiment of the present invention provides a V-cone household natural gas flow calculation device, such as Figure 3 As shown, the V-cone household natural gas flow calculation device includes:

[0111] The standard data acquisition module 1 is used to acquire the standard data of natural gas under standard reference conditions. For details, see the relevant description of step S1 in Example 1.

[0112] The first relationship determination module 2 is used to determine the first relationship between the volume flow rate of natural gas under standard reference conditions and the standard orifice differential pressure range according to the volume flow calculation formula of the V-cone flowmeter and standard data. For details, see the relevant description of step S2 in embodiment 1.

[0113] The second relationship determination module 3 is used to determine the second relationship between the volume flow rate of natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter according to the preset parameter information of the V-cone flowmeter and the first relationship. For details, see the relevant description of step S3 in embodiment 1.

[0114] The differential pressure range determination module 4 is used to determine the differential pressure range of the V-cone flowmeter by using the chord intercept method according to the second relationship and the preset parameter value. For details, see the relevant description of step S4 in embodiment 1.

[0115] The volume flow calculation module 5 is used to determine the volume flow of natural gas under the V-cone flowmeter according to the second relationship and the differential pressure range of the V-cone flowmeter. For details, see the relevant description of step S5 in embodiment 1.

[0116] Through the coordinated cooperation of the above-mentioned components, the V-cone household natural gas flow calculation device of the embodiment of the present invention realizes the calculation of household natural gas flow based on the V-cone flowmeter by combining the standard data of natural gas and the characteristics of the V-cone flowmeter itself, thereby providing an accurate data basis for the application of the V-cone flowmeter in household gas meters.

[0117] The V-cone household natural gas flow calculation device according to an embodiment of the present invention will be described in detail below in conjunction with specific application examples.

[0118] In a preferred embodiment, the first relationship generating module 2 obtains the first relationship between the volume flow rate of natural gas under standard reference conditions and the standard orifice differential pressure range according to the following formula:

[0119]

[0120] Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn represents the metering coefficient of volume flow, C represents the outflow coefficient, E represents the asymptotic velocity coefficient, d represents the opening diameter, and F represents the G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow at the pressure-taking hole on the upstream side of the orifice plate, and △p represents the differential pressure range of the airflow passing through the standard orifice plate.

[0121] In a preferred embodiment, the second relationship generation module 3 obtains the second relationship between the volume flow rate of natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter according to the following formula:

[0122]

[0123] Among them, q VnIt represents the volume flow rate of natural gas under standard reference conditions, A Vn represents the metering coefficient of volume flow, C represents the discharge coefficient, E represents the asymptotic velocity coefficient, β V Indicates the equivalent diameter ratio of the V-cone throttling device, D represents the inner diameter of the pipe, F G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow through the pressure-taking hole on the upstream side of the orifice plate, △p K Indicates the differential pressure range of air flowing through the V-cone flowmeter.

[0124] In a preferred embodiment, the above-mentioned preset parameter value includes a first parameter value and a second parameter value, such as Figure 4 As shown, the above-mentioned differential pressure range determination module 4 includes:

[0125] The first difference calculation submodule 41 is used to obtain the first difference according to the second relationship and the first parameter value. For details, see the relevant description of step S41 in embodiment 1.

[0126] The second difference calculation submodule 42 is used to obtain the second difference according to the second relationship and the second parameter value. For details, please refer to the relevant description of step S42 in embodiment 1.

[0127] The differential pressure range determination submodule 43 is used to determine the differential pressure range of the V-cone flowmeter using the chord intercept method according to the preset standard range, the first parameter value, the second parameter value, the first difference, and the second difference. For details, see the relevant description of step S43 in Example 1.

[0128] Through the coordinated cooperation of the above-mentioned components, the V-cone household natural gas flow calculation device of the embodiment of the present invention realizes the calculation of household natural gas flow based on the V-cone flowmeter by combining the standard data of natural gas and the characteristics of the V-cone flowmeter itself, thereby providing an accurate data basis for the application of the V-cone flowmeter in household gas meters.

[0129] Example 3

[0130] An embodiment of the present invention provides a non-transitory computer storage medium, which stores computer executable instructions, and the computer executable instructions can execute the V-cone household natural gas flow calculation method in any of the above method embodiments, wherein the above storage medium can be a disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory (Flash Memory), a hard disk (HardDisk Drive, abbreviated: HDD) or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above types of memories.

[0131] Those skilled in the art can understand that all or part of the processes in the above method embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above method embodiments. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0132] Example 4

[0133] An embodiment of the present invention provides a computer device, the structural diagram of which is shown in FIG. Figure 5 As shown, the computer device includes: one or more processors 410 and a memory 420, Figure 5 A processor 410 is taken as an example.

[0134] The above-mentioned computer device may further include: an input device 430 and an output device 440 .

[0135] The processor 410, the memory 420, the input device 430 and the output device 440 may be connected via a bus or other means. Figure 5 The example of connecting through bus is taken in the following.

[0136] The processor 410 may be a central processing unit (CPU). The processor 410 may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips. A general-purpose processor may be a microprocessor or the processor may be any conventional processor.

[0137] The memory 420, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer executable programs and modules, such as the program instructions / modules corresponding to the V-cone household natural gas flow calculation method in the embodiment of the present application. The processor 410 executes various functional applications and data processing of the server by running the non-transitory software programs, instructions and modules stored in the memory 420, that is, implements the V-cone household natural gas flow calculation method of the above method embodiment.

[0138] The memory 420 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created by the use of the processing device according to the V-cone household natural gas flow calculation method, etc. In addition, the memory 420 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some embodiments, the memory 420 may optionally include a memory remotely arranged relative to the processor 410, and these remote memories may be connected to the V-cone household natural gas flow calculation device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0139] The input device 430 can receive input digital or character information and generate key signal input related to user settings and function control related to the processing device of the V-cone domestic natural gas flow calculation operation. The output device 440 can include display devices such as a display screen.

[0140] One or more modules are stored in the memory 420, and when executed by one or more processors 410, the execution is as follows: Figure 1 or Figure 2 The method shown.

[0141] The above-mentioned product can execute the method provided by the embodiment of the present invention, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not fully described in the embodiment of the present invention, please refer to Figure 1 or Figure 2 Related description of the illustrated embodiment.

[0142] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A V-cone household natural gas flow calculation method, characterized in that: include: Obtain standard data of natural gas under standard reference conditions; Determine a first relationship between the volume flow rate of natural gas under standard reference conditions and the standard orifice differential pressure range according to the volume flow rate calculation formula of the V-cone flowmeter and the standard data; Determine a second relationship between the volume flow rate of the natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter according to the preset parameter information of the V-cone flowmeter and the first relationship; According to the second relationship and the preset parameter value, the differential pressure range of the V-cone flowmeter is determined by using the chord intercept method; The second relationship between the volume flow rate of the natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter is obtained according to the following formula: Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn represents the metering coefficient of volume flow, C represents the discharge coefficient, E represents the asymptotic velocity coefficient, β V Indicates the equivalent diameter ratio of the V-cone throttling device, D represents the inner diameter of the pipe, F G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow at the pressure-taking hole on the upstream side of the orifice plate, Δp K Indicates the differential pressure range of the airflow through the V-cone flowmeter; The preset parameter value includes a first parameter value and a second parameter value, and the method of determining the differential pressure range of the V-cone flowmeter by using the chord intercept method according to the second relationship and the preset parameter value includes: Obtaining a first difference value according to the second relationship and the first parameter value; Obtain a second difference value according to the second relationship and the second parameter value; Determine the differential pressure range of the V-cone flowmeter using the chord intercept method according to the preset standard range, the first parameter value, the second parameter value, the first difference, and the second difference; The volume flow rate of the natural gas under the V-cone flowmeter is determined according to the second relationship and the differential pressure range of the V-cone flowmeter.

2. The V-cone household natural gas flow calculation method according to claim 1, characterized in that: The first relationship between the volume flow rate of the natural gas under standard reference conditions and the standard orifice differential pressure range is obtained according to the following formula: Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn represents the metering coefficient of volume flow, C represents the outflow coefficient, E represents the asymptotic velocity coefficient, d represents the opening diameter, and F represents the G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow at the pressure-taking hole on the upstream side of the orifice plate, and Δp represents the differential pressure range of the airflow passing through the standard orifice plate.

3. A V-cone household natural gas flow calculation device, characterized in that: include: A standard data acquisition module (1) is used to acquire standard data of natural gas under standard reference conditions; A first relationship determination module (2) is used to determine a first relationship between the volume flow rate of the natural gas under standard reference conditions and the standard orifice differential pressure range according to a volume flow calculation formula of a V-cone flowmeter and the standard data; A second relationship determination module (3) is used to determine a second relationship between the volume flow rate of the natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter according to preset parameter information of the V-cone flowmeter and the first relationship; A differential pressure range determination module (4), used for determining the differential pressure range of the V-cone flowmeter by using a chord intercept method according to the second relationship and a preset parameter value; The second relationship between the volume flow rate of the natural gas under the V-cone flowmeter and the differential pressure range of the V-cone flowmeter is obtained according to the following formula: Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn represents the metering coefficient of volume flow, C represents the discharge coefficient, E represents the asymptotic velocity coefficient, β V Indicates the equivalent diameter ratio of the V-cone throttling device, D represents the inner diameter of the pipe, F G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow at the pressure-taking hole on the upstream side of the orifice plate, Δp K Indicates the differential pressure range of the airflow through the V-cone flowmeter; The preset parameter value comprises a first parameter value and a second parameter value, and the differential pressure range determination module (4) comprises: A first difference calculation submodule (41), configured to obtain a first difference according to the second relationship and the first parameter value; A second difference calculation submodule (42), configured to obtain a second difference according to the second relationship and the second parameter value; A differential pressure range determination submodule (43) is used to determine the differential pressure range of the V-cone flowmeter by using a chord intercept method according to a preset standard range, the first parameter value, the second parameter value, the first difference, and the second difference; A volume flow calculation module (5) is used to determine the volume flow of the natural gas under the V-cone flow meter according to the second relationship and the differential pressure range of the V-cone flow meter.

4. The V-cone household natural gas flow calculation device according to claim 3, characterized in that: The first relationship generating module (2) obtains a first relationship between the volume flow rate of the natural gas under standard reference conditions and the standard orifice differential pressure range according to the following formula: Among them, q Vn It represents the volume flow rate of natural gas under standard reference conditions, A Vn represents the metering coefficient of volume flow, C represents the outflow coefficient, E represents the asymptotic velocity coefficient, d represents the opening diameter, and F represents the G represents the relative density coefficient, ε represents the expansion coefficient, F Z Indicates the supercompression factor, F T represents the flow temperature coefficient, P1 represents the absolute static pressure of the airflow at the pressure-taking hole on the upstream side of the orifice plate, and Δp represents the differential pressure range of the airflow passing through the standard orifice plate.

5. A non-transitory computer-readable storage medium, characterized in that: The non-transitory computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the V-cone household natural gas flow calculation method according to any one of claims 1-2 is implemented.

6. A computer device, characterized in that: include: At least one processor (410); and a memory (420) communicatively connected to the at least one processor (410), wherein: The memory (420) stores instructions executable by the at least one processor (410), and the instructions are executed by the at least one processor (410) so that the at least one processor (410) executes the V-cone household natural gas flow calculation method according to any one of claims 1-2.

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