Intelligent prepayment steam flowmeter

Abstract

The invention relates to the technical field of flow measurement, and particularly discloses an intelligent prepayment steam flowmeter which comprises a measuring pipe, a shell and a reducing pipe, a measuring block and a probe are installed in the measuring pipe, the side, facing the air inlet end of the measuring pipe, of the measuring block is an incident flow face, and the side, facing the air outlet end of the measuring pipe, of the measuring block is a back flow face. A first pressure cavity and a second pressure cavity are formed in the measuring block, detection rods are installed in the first pressure cavity and the second pressure cavity, the detection rods are connected with a differential pressure sensor outside the measuring tube, a plurality of first differential pressure holes are formed in the incident flow surface of the measuring block, and a plurality of second differential pressure holes are formed in the back flow surface of the measuring block. The differential pressure sensor, the measuring block, the detection rod and the probe are arranged to measure the density and the mass flow of the fluid, a more stable and accurate measuring result can be provided, temperature and pressure compensation is not needed, and the measuring cost of the steam flow is reduced.

Description

Technical Field

[0001] The invention specifically relates to the technical field of flow meters, in particular to an intelligent prepaid steam flow meter. Background Art

[0002] Steam flowmeter is a meter specially designed to measure the flow of steam (or other gases). Due to the special properties of steam, such as compressibility and the influence of temperature and pressure on its density, it is necessary to use a flowmeter suitable for these conditions. Steam flowmeters can be divided into the following types according to their working principles:

[0003] Differential pressure steam flow meter: calculates flow rate by measuring the pressure difference generated when steam flows through a throttling device (such as an orifice plate, nozzle or venturi tube); velocity steam flow meter: measures the flow rate of steam in the pipeline and then multiplies it by the cross-sectional area of ​​the pipeline to obtain the flow rate; thermal steam flow meter: based on the thermal conductivity characteristics of steam, measures the heat loss when passing through the sensor to determine the flow rate; ultrasonic steam flow meter: uses the propagation characteristics of ultrasonic waves in steam to measure the flow rate

[0004] In steam measurement, there is often a deviation between the design conditions and the actual conditions. The expansion coefficient, flow coefficient and other parameters of the steam flow meter will change, and the steam density will change significantly. The flow value displayed by the measurement will have a large error compared with the actual value. For prepaid steam flow meters, if the measurement error is too large, it will affect the user's payment experience. The existing technology uses temperature or pressure compensation to correct the measurement results and improve the measurement accuracy, but this compensation method requires additional temperature and pressure sensors, which increases the measurement cost of the steam flow and reduces the profit of the flow supplier. Summary of the invention

[0005] The object of the present invention is to provide an intelligent prepaid steam flow meter to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A smart prepaid steam flow meter comprises a measuring tube, a shell and a reducing tube connected to the measuring tube, a connecting flange is arranged at the end of the reducing tube, the connecting flange is used to connect the pipeline to be measured, a measuring block and a probe are installed inside the measuring tube, the measuring block is fixedly installed inside the measuring tube, the side of the measuring block facing the air inlet end of the measuring tube is the upstream surface, the side of the measuring block facing the exhaust end of the measuring tube is the downstream surface, the probe is installed inside the measuring tube; a first pressure chamber and a second pressure chamber are provided inside the measuring block, detection rods are installed inside the first pressure chamber and the second pressure chamber, the detection rod is connected to a differential pressure sensor outside the measuring tube, a plurality of first differential pressure holes are provided on the upstream surface of the measuring block, a plurality of second differential pressure holes are provided on the downstream surface of the measuring block, the first differential pressure hole is connected to the first pressure chamber, and the second differential pressure hole is connected to the second pressure chamber.

[0008] As a further solution of the present invention: the first pressure chamber and the second pressure chamber have the same structure, the first pressure chamber is arranged close to the upstream surface of the measuring block, and the second pressure chamber is arranged close to the downstream surface of the measuring block; the measuring block is a triangular prism structure, and the ratio of the upstream surface width of the measuring block to the inner diameter of the pipeline is 0.28.

[0009] As a further solution of the present invention: four first differential pressure holes are provided, and two second differential pressure holes are provided.

[0010] As a further solution of the present invention: the calculation formula for measuring fluid density using a differential pressure sensor, a measuring block, a detection rod and a probe is:

[0011]

[0012] Where: ε is the expansion coefficient of the fluid, γ is the flow coefficient, D is the diameter of the measuring tube, K is the instrument coefficient, ΔP is the pressure difference, and f is the eddy current frequency.

[0013] As a further solution of the present invention: the calculation formula for measuring the fluid mass flow rate using the differential pressure sensor, the measuring block, the detection rod and the probe is:

[0014]

[0015] Where: ε is the expansion coefficient of the fluid, γ is the flow coefficient, D is the diameter of the measuring tube, K is the instrument coefficient, ΔP is the pressure difference, and f is the eddy current frequency.

[0016] As a further solution of the present invention: a controller and a display screen are also installed on the housing, the controller is connected to a remote terminal, and the controller includes a data receiving module, a data processing module, a data sending module and a billing module, wherein:

[0017] A data receiving module is used to obtain measurement parameters, including pressure difference and eddy current frequency; and is also used to obtain the payment amount of the user;

[0018] A data processing module, used for calculating the usage flow rate of the fluid according to the measured parameters;

[0019] The billing module is used to calculate the user's traffic usage quota based on the user's payment amount and allocate the traffic usage quota to the user; it is also used to obtain the user's usage traffic and usage time, and send an alarm signal when the user's usage traffic or usage time reaches the alarm threshold;

[0020] The remote terminal is used to send the user's payment amount and the selection result of the traffic usage mode. When the user completes the recharge, the user's payment amount is sent to the billing module through the remote terminal.

[0021] As a further solution of the present invention: the controller further includes an alarm module and a timing module, wherein:

[0022] An alarm module is used to obtain an alarm signal, and when the alarm signal is received, it sends a reminder of insufficient balance to the user to remind the user to renew the payment;

[0023] The timing module is used to time the time users use the traffic usage service.

[0024] As a further solution of the present invention: a method for calculating a user's traffic usage quota according to the user's payment amount and allocating the traffic usage quota to the user comprises the following steps:

[0025] Obtaining the user's payment amount and the selection result of the flow usage mode, wherein the flow usage mode includes a usage quota mode and a usage time mode, wherein the usage quota mode is: converting the user's payment amount into a usage quota of the fluid flow; the usage time mode is: converting the user's payment amount into a usage time quota of the fluid flow;

[0026] The user's payment amount is converted into a credit value according to the selection result of the traffic usage mode, and the credit value includes a usage credit and a usage time credit.

[0027] As a further solution of the present invention: the method for converting the user's payment amount into a credit value according to the selection result of the traffic usage mode is:

[0028]

[0029] Where: L a Indicates the flow quota; L bIt represents the usage time quota; α represents the traffic quota ratio coefficient; β represents the usage time quota ratio coefficient; M1 represents the user's payment amount; M0 represents the service fee of the traffic usage service; x is the adjustment factor.

[0030] As a further solution of the present invention: the controller also includes a data sending module and a communication module, and the controller is connected to the remote terminal, the probe and the differential pressure sensor through the communication module; the data processing module is connected to the data sending module, and the data sending module is connected to the display screen.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention can provide more stable and accurate measurement results by setting a differential pressure sensor, a measuring block, a detection rod and a probe to measure the density and mass flow rate of the fluid, thereby eliminating the need for temperature and pressure compensation and reducing the measurement cost of the steam flow; the present invention also provides a variety of flow usage modes for users to choose from, allowing users to select the flow usage method according to actual usage needs, which is beneficial to reducing the user's usage cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a structural diagram of the intelligent prepaid steam flow meter.

[0033] Figure 2 A partial cross-sectional view of the smart prepayment steam flow meter.

[0034] Figure 3 Schematic diagram of the structure of the measuring block in the intelligent prepayment steam flow meter Figure 1 .

[0035] Figure 4 Schematic diagram of the structure of the measuring block in the intelligent prepayment steam flow meter Figure 2 .

[0036] Figure 5 This is a cross-sectional view of the measuring block in the smart prepayment steam flow meter.

[0037] Figure 6 This is the structural block diagram of the controller in the intelligent prepayment steam flow meter.

[0038] In the figure: 10-measuring tube, 20-housing, 21-controller, 22-display screen, 23-data receiving module, 24-data processing module, 25-data sending module, 26-billing module, 27-alarm module, 28-communication module, 29-timing module, 30-reducing tube, 31-connecting flange, 40-probe, 50-measuring device, 51-differential pressure sensor, 52-measuring block, 521-first pressure chamber, 522-second pressure chamber, 523-first differential pressure hole, 524-second differential pressure hole, 525-detection rod, 60-valve switch, 70-remote terminal. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0040] See also Figure 1-Figure 6 In an embodiment of the present invention, an intelligent prepaid steam flow meter includes a measuring tube 10, a shell 20, and a reducing tube 30 connected to the measuring tube 10, a connecting flange 31 is provided at the end of the reducing tube 30, and the connecting flange 31 is used to connect the pipeline to be measured; a measuring device 50 and a probe 40 are installed inside the measuring tube 10, the measuring device 50 includes a differential pressure sensor 51 and a measuring block 52, the measuring block 52 is fixedly installed inside the measuring tube 10, the side of the measuring block 52 facing the air inlet end of the measuring tube 10 is the upstream surface, and the side of the measuring block 52 facing the exhaust end of the measuring tube 10 is the back flow surface, the probe 40 is installed inside the measuring tube 10, and the installation position of the probe 40 is located in the area between the back flow surface of the measuring block 52 and the exhaust end of the measuring tube 10; a first pressure chamber 521 and a second pressure chamber 522 are opened inside the measuring block 52, and a detection rod 525 is installed inside the first pressure chamber 521 and the second pressure chamber 522, and the detection rod 525 is connected to the differential pressure sensor 51 outside the measuring tube 10, and the measuring block A plurality of first differential pressure holes 523 are provided on the upstream surface of the measuring block 52, and a plurality of second differential pressure holes 524 are provided on the downstream surface of the measuring block 52. The first differential pressure holes 523 are connected to the first pressure chamber 521, and the second differential pressure holes 524 are connected to the second pressure chamber 522. When measuring the flow rate, the fluid enters from the air inlet end of the measuring tube 10 and collides with the measuring block 52, and forms an alternating vortex on one side of the downstream surface of the measuring block 52. The frequency of the vortex is proportional to the flow velocity of the fluid, and the flow velocity of the fluid is proportional to the volume flow rate. The probe 40 determines the volume flow rate of the fluid by measuring the frequency of the eddy current; during the flow of the fluid, a pressure difference is generated between the upstream surface and the downstream surface of the measuring block 52. The detection rod 525 inside the first pressure chamber 521 is used to detect the pressure on the upstream surface of the measuring block 52, and the detection rod 525 inside the second pressure chamber 522 is used to detect the pressure on the downstream surface of the measuring block 52. The difference between the pressure on the upstream surface and the pressure on the downstream surface is the pressure difference, which is proportional to the flow rate of the fluid. The differential pressure sensor 51 can measure the volume flow rate of the fluid by measuring the pressure difference.

[0041] In the embodiment of the present application, the first pressure chamber 521 and the second pressure chamber 522 have the same structure. The first pressure chamber 521 is arranged close to the upstream surface of the measuring block 52, and the second pressure chamber 522 is arranged close to the downstream surface of the measuring block 52, so as to ensure that the pressure distribution of the two chambers is uniform, thereby generating a certain pressure difference; the measuring block 52 is a triangular prism structure, and the ratio of the upstream surface width of the measuring block 52 to the inner diameter of the pipe is 0.28. When the ratio is small, the vortex generator has a greater influence on the vortex generation; when the ratio exceeds 0.3, the shape of the vortex generator has a smaller influence on the vortex, while the influence of the inner wall of the pipe on the flow rate increases, which affects the stability of the Strouhal value.

[0042] In the embodiment of the present application, four first differential pressure holes 523 are provided, and two second differential pressure holes 524 are provided. When the fluid in the measuring tube 10 forms a fully developed turbulent flow, its flow velocity is exponential and rotationally symmetrical, that is, the flow velocity in the same radial direction is equal. Therefore, only a few differential pressure holes are needed to reflect the overall situation.

[0043] When measuring gas and steam flow in an industrial environment, the working state parameters of the fluid (such as pressure and temperature) will change frequently, thereby causing changes in density. In this case, the measurement of volume flow may result in large errors, while the measurement of mass flow is not affected by these changes, and can provide more stable and accurate measurement results. In the prior art, for fluids with unknown density or changing density, temperature and pressure compensation are required to measure density. In order to simplify the measurement process, reduce measurement parameters, and reduce measurement costs, this embodiment uses a differential pressure sensor 51, a measuring block 52, a detection rod 525, and a probe 40 to measure the mass flow of the fluid, specifically:

[0044] The formula for calculating fluid density is:

[0045]

[0046] The calculation formula for fluid mass flow rate is:

[0047]

[0048] Where: ε is the expansion coefficient of the fluid, γ is the flow coefficient, D is the diameter of the measuring tube 10, K is the instrument factor, the unit is 1 / m 3 , ΔP is the pressure difference, which is measured by the differential pressure sensor 51 , and f is the eddy current frequency, which is measured by the eddy current frequency probe 40 .

[0049] It can be seen from the calculation formulas for fluid density and fluid mass flow that in this embodiment, the mass flow of the fluid can be calculated based on the pressure difference between the upstream and downstream surfaces of the measuring block 52 and the vortex frequency on the downstream surface of the measuring block 52, thereby eliminating the need for temperature and pressure compensation.

[0050] In the embodiment of the present application, the housing 20 is further provided with a controller 21 and a display screen 22, the controller 21 is connected with a remote terminal 70 and a valve switch 60, the remote terminal 70 is a device used by a user, such as a PC, a mobile phone, etc., the valve switch 60 is installed at the inlet end of the reduced diameter tube 30, when the valve switch 60 is turned on, the fluid enters the interior of the measuring tube 10 from the reduced diameter tube 30, when the valve switch 60 is closed, the fluid cannot enter the interior of the measuring tube 10, it should be noted that the valve switch 60 is a prior art, and this embodiment will not be described in detail here;

[0051] The controller 21 includes a data receiving module 23, a data processing module 24, a data sending module 25 and a charging module 26, wherein:

[0052] The data receiving module 23 is used to obtain measurement parameters, including pressure difference and eddy current frequency; and is also used to obtain the payment amount of the user;

[0053] The data processing module 24 is used to calculate the usage flow rate of the fluid according to the measured parameters. The calculation method is to calculate according to the calculation formula of the fluid mass flow rate. It should be noted that the flow rate calculated by the calculation formula is the instantaneous flow rate. The usage flow rate of the fluid is obtained by multiplying the instantaneous flow rate by the usage time.

[0054] The billing module 26 is used to calculate the user's traffic usage quota according to the user's payment amount and allocate the traffic usage quota to the user; it is also used to obtain the user's usage traffic and usage time, and send an alarm signal when the user's usage traffic or usage time reaches an alarm threshold;

[0055] The remote terminal 70 is used to send the user's payment amount and the selection result of the traffic usage mode. When the user completes the recharge, the user's payment amount is sent to the billing module 26 through the remote terminal 70.

[0056] In the embodiment of the present application, the controller 21 further includes an alarm module 27 and a timing module 29, wherein:

[0057] The alarm module 27 is used to obtain an alarm signal. When the alarm signal is received, a prompt of insufficient balance is sent to the user to remind the user to renew. When the user does not renew and the balance is insufficient, the billing module 26 controls the valve switch 60 to close.

[0058] The timing module 29 is used to time the time when the user uses the traffic usage service. The timing starts when the user completes the recharge of the amount and ends when the amount is used up.

[0059] In an embodiment of the present application, a method for calculating a user's traffic usage quota according to a payment amount of the user and allocating the traffic usage quota to the user includes the following steps:

[0060] Step S101, obtaining the user's payment amount and the selection result of the flow usage mode, wherein the flow usage mode includes a usage quota mode and a usage time mode, wherein the usage quota mode is: converting the user's payment amount into a usage quota of fluid flow, the user can use the flow of the usage quota, and when the flow used by the user reaches the usage quota, the flow usage service is stopped; the usage time mode is: converting the user's payment amount into a usage time quota of fluid flow, the user uses the flow within the usage time quota, and when the user's service usage time reaches the usage time quota, the flow usage service is stopped;

[0061] Step S102: converting the user's payment amount into a credit value according to the selection result of the traffic usage mode, wherein the credit value includes a usage credit and a usage time credit;

[0062] In step S102 of the embodiment of the present application, the method for converting the user's payment amount into a credit value according to the selection result of the traffic usage mode is:

[0063]

[0064] Where: L a Indicates the flow quota; L b It represents the usage time quota; α represents the traffic quota ratio coefficient; β represents the usage time quota ratio coefficient; M1 represents the user's payment amount; M0 represents the service fee of the traffic usage service, which includes the installation fee and maintenance fee of the traffic meter; x is the adjustment factor, and the value of the adjustment factor is determined by the traffic provider according to the usage environment.

[0065] Further, in the embodiment of the present application, for the usage time quota ratio coefficient β, when the user is using it for the first time, β can take a smaller value, such as [0.2-0.4], to attract users to use the traffic usage service; for users who use it multiple times, the value of β is determined by the user's historical usage, and the specific calculation method is:

[0066]

[0067] In the formula, t is the user's historical traffic usage duration, and T is the user's historical purchased usage time quota.

[0068] In an embodiment of the present application, the controller 21 also includes a data sending module 25 and a communication module 28. The controller 21 is connected to the remote terminal 70, the probe 40 and the differential pressure sensor 51 through the communication module 28; the data processing module 24 is connected to the data sending module 25, and the data sending module 25 is connected to the display screen 22. The data processing module 24 sends the fluid usage flow rate to the display screen 22 through the data sending module 25, and displays it on the display screen 22.

[0069] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0070] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An intelligent prepaid steam flow meter, comprising a measuring tube (10), a housing (20) and a reducing tube (30) connected to the measuring tube (10), wherein a connecting flange (31) is provided at the end of the reducing tube (30), and the connecting flange (31) is used to connect to a pipeline to be measured, characterized in that: A measuring block (52) and a probe (40) are installed inside the measuring tube (10); the measuring block (52) is fixedly installed inside the measuring tube (10); the side of the measuring block (52) facing the air inlet end of the measuring tube (10) is a frontal surface; the side of the measuring block (52) facing the air outlet end of the measuring tube (10) is a back surface; the probe (40) is installed inside the measuring tube (10); a first pressure chamber (521) and a second pressure chamber (522) are provided inside the measuring block (52); the first pressure chamber (521) and the second pressure chamber (522) are provided inside the measuring tube (10); A detection rod (525) is installed inside the first pressure chamber (521) and the second pressure chamber (522), and the detection rod (525) is connected to the differential pressure sensor (51) outside the measuring tube (10). A plurality of first differential pressure holes (523) are opened on the upstream surface of the measuring block (52), and a plurality of second differential pressure holes (524) are opened on the downstream surface of the measuring block (52). The first differential pressure holes (523) are connected to the first pressure chamber (521), and the second differential pressure holes (524) are connected to the second pressure chamber (522).

2. The intelligent prepaid steam flow meter according to claim 1, characterized in that: The first pressure chamber (521) and the second pressure chamber (522) have the same structure; the first pressure chamber (521) is arranged close to the flow-facing surface of the measuring block (52), and the second pressure chamber (522) is arranged close to the flow-receiving surface of the measuring block (52); the measuring block (52) is a triangular prism structure, and the ratio of the width of the flow-facing surface of the measuring block (52) to the inner diameter of the pipeline is 0.

28.

3. The intelligent prepaid steam flow meter according to claim 2, characterized in that: Four first differential pressure holes (523) are provided, and two second differential pressure holes (524) are provided.

4. The intelligent prepaid steam flow meter according to claim 1, characterized in that: The calculation formula for measuring the fluid density using the differential pressure sensor (51), the measuring block (52), the detection rod (525) and the probe (40) is: Wherein: ε is the expansion coefficient of the fluid, γ is the flow coefficient, D is the diameter of the measuring tube (10), K is the instrument factor, ΔP is the pressure difference, and f is the vortex frequency.

5. The intelligent prepaid steam flow meter according to claim 1, characterized in that: The calculation formula for measuring the fluid mass flow rate using the differential pressure sensor (51), the measuring block (52), the detection rod (525) and the probe (40) is: Wherein: ε is the expansion coefficient of the fluid, γ is the flow coefficient, D is the diameter of the measuring tube (10), K is the instrument factor, ΔP is the pressure difference, and f is the vortex frequency.

6. The intelligent prepaid steam flow meter according to claim 1, characterized in that: The housing (20) is also provided with a controller (21) and a display screen (22). The controller (21) is connected to a remote terminal (70) and a valve switch (60). The controller (21) includes a data receiving module (23), a data processing module (24), a data sending module (25) and a billing module (26), wherein: A data receiving module (23) is used to obtain measurement parameters, including pressure difference and eddy current frequency; and is also used to obtain a payment amount of a user; A data processing module (24) is used to calculate the usage flow rate of the fluid according to the measured parameters; The charging module (26) is used to calculate the user's traffic usage quota according to the user's payment amount and allocate the traffic usage quota to the user; it is also used to obtain the user's usage traffic and usage time, and send an alarm signal when the user's usage traffic or usage time reaches an alarm threshold; The remote terminal (70) is used to send the user's payment amount and the selection result of the traffic usage mode. When the user completes the recharge, the user's payment amount is sent to the billing module (26) through the remote terminal (70).

7. The intelligent prepaid steam flow meter according to claim 6, characterized in that: The controller (21) further comprises an alarm module (27) and a timing module (29), wherein: An alarm module (27) is used to obtain an alarm signal and send a reminder of insufficient balance to the user when the alarm signal is received, so as to remind the user to renew the payment; The timing module (29) is used to time the time when the user uses the traffic usage service.

8. The intelligent prepaid steam flow meter according to claim 7, characterized in that: The method of calculating the traffic usage quota of a user according to the payment amount of the user and allocating the traffic usage quota to the user comprises the following steps: Obtaining the user's payment amount and the selection result of the flow usage mode, wherein the flow usage mode includes a usage quota mode and a usage time mode, wherein the usage quota mode is: converting the user's payment amount into a usage quota of the fluid flow; the usage time mode is: converting the user's payment amount into a usage time quota of the fluid flow; The user's payment amount is converted into a credit value according to the selection result of the traffic usage mode, and the credit value includes a usage credit and a usage time credit.

9. The intelligent prepaid steam flow meter according to claim 8, characterized in that: The method for converting the user's payment amount into a credit value based on the selection result of the traffic usage mode is as follows: Where: L a Indicates the flow quota; L b It represents the usage time quota; α represents the traffic quota ratio coefficient; β represents the usage time quota ratio coefficient; M1 represents the user's payment amount; M0 represents the service fee of the traffic usage service; x is the adjustment factor.

10. The intelligent prepaid steam flow meter according to claim 9, characterized in that: The controller (21) further comprises a data transmission module (25) and a communication module (28), and the controller (21) is connected to a remote terminal (70), a probe (40) and a differential pressure sensor (51) via the communication module (28); the data processing module (24) is connected to the data transmission module (25), and the data transmission module (25) is connected to the display screen (22).

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