Disclosure of Invention
The invention aims to provide a gas mass flow measuring device and a method, which are used for measuring the mass flow of mixed gas.
In order to achieve the purpose, the invention provides the following scheme:
a gas mass flow measuring device comprises a vortex frequency signal detection component, a differential pressure signal detection component and a control calculation component;
the vortex frequency signal detection component is provided with a first pressure taking hole and a second pressure taking hole and is connected with the differential pressure signal detection component; the vortex frequency signal detection component is used for detecting a vortex frequency signal of the gas to be detected;
the differential pressure signal detection part is used for acquiring a first air pressure signal of the gas to be detected through the first pressure acquiring hole, acquiring a second air pressure signal of the gas to be detected through the second pressure acquiring hole, and acquiring a differential pressure signal of the gas to be detected according to the first air pressure signal and the second air pressure signal;
the control calculation component is respectively connected with the vortex frequency signal detection component and the differential pressure signal detection component and is used for receiving the vortex frequency signal of the gas to be detected and the differential pressure signal of the gas to be detected and calculating the mass flow of the gas to be detected according to the vortex frequency signal of the gas to be detected and the differential pressure signal of the gas to be detected.
Optionally, the vortex frequency signal detection component comprises a vortex generator, a signal detection probe and a shell;
the shell is provided with the first pressure measuring hole and the second pressure measuring hole;
the vortex generating body is arranged in the shell and used for processing the gas to be detected so as to enable the gas to be detected to generate a vortex;
the signal detection probe is arranged in the shell, is connected with the control calculation component, and is used for detecting the vortex frequency signal of the gas to be detected and sending the vortex frequency signal to the control calculation component.
Optionally, the first pressure taking hole is arranged at a first end of the housing, and the first end of the housing is an end of the gas to be detected entering the housing; the second pressure taking hole is formed in the second end of the shell, and the second end of the shell is used for outputting the gas to be detected to one end of the shell.
Optionally, the differential pressure signal detection part comprises a differential pressure diaphragm capsule, a first pressure guide pipe and a second pressure guide pipe;
one end of the first pressure guide pipe is connected with the vortex frequency signal detection component through the first pressure taking hole, and the other end of the first pressure guide pipe is connected with the differential pressure diaphragm capsule;
one end of the second pressure guide pipe is connected with the vortex frequency signal detection component through the second pressure taking hole, and the other end of the second pressure guide pipe is connected with the differential pressure diaphragm capsule;
the differential pressure diaphragm capsule is also connected with the control calculation part;
the differential pressure bellows is used for:
acquiring a first air pressure signal of the gas to be detected through the first pressure guide pipe;
acquiring a second air pressure signal of the gas to be detected through the second pressure guide pipe;
and calculating a differential pressure signal of the gas to be measured according to the first air pressure signal and the second air pressure signal, and sending the differential pressure signal to the control calculation part.
Optionally, the first pressure guide pipe is connected with a first air inlet hole of the differential pressure diaphragm capsule through a first needle valve; and the second pressure guide pipe is connected with a second air inlet hole of the differential pressure diaphragm capsule through a second needle valve.
Optionally, the gas mass flow measurement device further comprises:
the communication component is connected with the control calculation component and is used for wirelessly transmitting the mass flow of the gas to be detected;
and the solar component is connected with the control calculation component and is used for providing power supply for the control calculation component.
Optionally, the control calculation component further comprises a communication circuit, a solar management circuit and a single chip microcomputer;
the communication component is connected with the singlechip through the communication circuit;
the solar component is connected with the singlechip through the solar management circuit.
Optionally, the control calculation component includes a differential pressure signal AD conversion circuit, a frequency signal AD conversion circuit, a setting key input circuit, a mass flow DA conversion circuit, and a single chip microcomputer;
the differential pressure signal AD conversion circuit is respectively connected with the differential pressure signal detection part and the single chip microcomputer, and is used for converting the differential pressure signal of the gas to be detected into a differential pressure digital signal and sending the differential pressure digital signal to the single chip microcomputer;
the frequency signal AD conversion circuit is respectively connected with the vortex frequency signal detection component and the singlechip, and is used for converting the vortex frequency signal of the gas to be detected into a frequency digital signal and sending the frequency digital signal to the singlechip;
the setting key input circuit is connected with the singlechip and is used for inputting the factory calibration coefficient of the vortex frequency signal detection part to the singlechip;
the single chip microcomputer is used for calculating the mass flow of the gas to be measured according to the differential pressure digital signal, the frequency digital signal and the factory calibration coefficient;
and the mass flow DA conversion circuit is connected with the singlechip and is used for converting the mass flow of the gas to be detected into a mass flow signal.
In order to achieve the above purpose, the invention also provides the following scheme:
a method of gas mass flow measurement, comprising:
acquiring a differential pressure signal of the gas to be detected output by a differential pressure signal detection part;
acquiring a vortex frequency signal of the gas to be detected output by a vortex frequency signal detection component;
and calculating the gas mass flow of the gas to be measured according to the differential pressure signal and the vortex frequency signal.
Optionally, the calculating the gas mass flow of the gas to be measured according to the differential pressure signal and the vortex frequency signal specifically includes:
according to the formula
Calculating the gas mass flow of the gas to be detected;
wherein,
rho represents gas real-time density, k represents instrument coefficient, f represents vortex frequency signal of gas to be measured, alpha represents flow coefficient, delta P represents differential pressure signal of gas to be measured, q represents pressure difference signal of gas to be measured
mRepresenting the mass flow of the gas to be measured.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
set up first pressure hole and second on swirl frequency signal detection part and get the pressure hole, differential pressure signal detection part is connected with swirl frequency signal detection part to get the pressure hole through first pressure hole and second and obtain the differential pressure signal of the gas that awaits measuring, avoided using subassembly such as orifice plate, make device simple structure, practice thrift the cost. The control calculation part acquires the vortex frequency signal of the gas to be measured detected by the vortex frequency signal detection part, also acquires the differential pressure signal detected by the differential pressure signal detection part, and calculates the mass flow of the gas to be measured according to the vortex frequency signal and the differential pressure signal, thereby realizing the calculation and measurement of the flow mass of the gas.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a gas mass flow measuring device and a method, which greatly meet the measurement requirement of the mass flow of mixed gas.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
Example one
As shown in fig. 1, the present embodiment provides a gas mass flow rate measurement device including a swirl frequency signal detection section, a differential pressure signal detection section, and a control calculation section; the vortex frequency signal detection component is provided with a first pressure taking hole and a second pressure taking hole and is connected with the differential pressure signal detection component; the vortex frequency signal detection component is used for detecting a vortex frequency signal of the gas to be detected.
The differential pressure signal detection part is used for acquiring a first air pressure signal of the gas to be detected through the first pressure acquiring hole, acquiring a second air pressure signal of the gas to be detected through the second pressure acquiring hole, and acquiring the differential pressure signal of the gas to be detected according to the first air pressure signal and the second air pressure signal.
The control calculation component is respectively connected with the vortex frequency signal detection component and the differential pressure signal detection component and is used for receiving the vortex frequency signal of the gas to be detected and the differential pressure signal of the gas to be detected and calculating the mass flow of the gas to be detected according to the vortex frequency signal of the gas to be detected and the differential pressure signal of the gas to be detected.
Specifically, the vortex frequency signal detection means includes a vortex generator 102, a signal detection probe 103, and a housing 101; the shell 101 is provided with the first pressure measuring hole and the second pressure measuring hole; the vortex generating body 102 is arranged in the shell 101, and the vortex generating body 102 is used for processing the gas to be detected so as to generate a vortex; the signal detection probe 103 is arranged in the shell 101 and connected with the control calculation component, and the signal detection probe 103 is used for detecting a vortex frequency signal of the gas to be detected and sending the vortex frequency signal to the control calculation component. The signal detection probe 103 is directly connected with the control and calculation part 301 through a vortex street signal output pipe 206. Preferably, the shape of the housing 101 is elliptical, but is not limited to elliptical; the shape of the housing 101 can be customized according to actual needs.
In this embodiment, the first pressure tapping hole is disposed at a first end of the casing 101, where the first end of the casing 101 is an end of the casing 101 where the gas to be measured enters; the second pressure measuring hole is formed in the second end of the casing 101, the second end of the casing 101 is one end of the casing 101, through which the gas to be measured is output, and the specific arrangement is as shown in fig. 1. In practical applications, the vortex generator 102 and the signal detection probe 103 can form a vortex street flow sensor, wherein the vortex generator 102 generates a vortex in the gas to be detected, the signal detection probe 103 detects the frequency of the generated vortex, and the gas flow is calculated according to the vortex frequency. Meanwhile, the differential pressure signal detection part acquires the gas pressure difference of the gas flowing through the inside of the shell 101 through the first pressure taking hole and the second pressure taking hole, and then the gas flow can be calculated through the gas pressure difference, wherein the first pressure taking hole, the second pressure taking hole and the differential pressure signal detection part can form a differential pressure type flow sensor. The embodiment structurally integrates a vortex street flow sensor and a differential pressure type flow sensor, and the vortex street flow sensor and the differential pressure type flow sensor respectively work independently and do not influence each other.
The differential pressure signal detection part comprises a differential pressure diaphragm capsule 201, a first pressure guide pipe 203 and a second pressure guide pipe 205; one end of the first pressure guide pipe 203 is connected with the vortex frequency signal detection component through the first pressure taking hole, and the other end of the first pressure guide pipe 203 is connected with the differential pressure diaphragm capsule 201; one end of the second pressure guide pipe 205 is connected to the swirl frequency signal detection unit through the second pressure taking hole, and the other end of the second pressure guide pipe 205 is connected to the differential pressure diaphragm 201; the differential pressure diaphragm capsule 201 is also connected with the control and calculation part; the differential pressure diaphragm capsule 201 is used for acquiring a first air pressure signal of the gas to be detected through the first pressure guide pipe 203, acquiring a second air pressure signal of the gas to be detected through the second pressure guide pipe 205, calculating a differential pressure signal of the gas to be detected according to the first air pressure signal and the second air pressure signal, and sending the differential pressure signal to the control calculation part.
Specifically, the first pressure guide pipe 203 is connected with a first air inlet hole of the differential pressure diaphragm capsule 201 through a first needle valve 202; the second pressure guiding pipe 205 is connected with a second air inlet hole of the differential pressure diaphragm capsule 201 through a second needle valve 204. In the embodiment of the present invention, the first pressure guiding pipe 203 is a high-pressure part pressure guiding pipe, and the second pressure guiding pipe 205 is a low-pressure part pressure guiding pipe; a first air inlet hole of the differential pressure diaphragm capsule 201 is a high-pressure air inlet hole, and a second air inlet hole of the differential pressure diaphragm capsule 201 is a low-pressure air inlet hole; the first needle valve 202 is a high pressure part needle valve and the second needle valve 204 is a low pressure part needle valve.
Preferably, the gas mass flow measuring device further comprises a communication component 402 and a solar component 401; the communication component 402 is connected with the control calculation component 301, and the communication component 402 is used for wirelessly transmitting the mass flow of the gas to be detected; the solar component 401 is connected with the control computing component 301, and the solar component 401 is used for providing power for the control computing component 301. Specifically, the control calculation component 301 further includes a communication circuit 35, a solar management circuit 36, and a single chip 38; the communication component 402 is connected with the single chip microcomputer 38 through the communication circuit 35; the solar component 401 is connected with the single chip microcomputer 38 through the solar management circuit 36.
As shown in fig. 2, the control calculation unit 301 includes a differential pressure signal AD conversion circuit 31, a frequency signal AD conversion circuit 32, a setting key input circuit 33, a mass flow rate DA conversion circuit 37, and a single chip microcomputer 38. The differential pressure signal AD conversion circuit 31 is respectively connected with the differential pressure signal detection part and the single chip microcomputer 38, and the differential pressure signal AD conversion circuit 31 is used for converting the differential pressure signal of the gas to be detected into a differential pressure digital signal and sending the differential pressure digital signal to the single chip microcomputer 38; the frequency signal AD conversion circuit 32 is connected to the vortex frequency signal detection unit and the single chip microcomputer 38, and the frequency signal AD conversion circuit 32 is configured to convert the vortex frequency signal of the gas to be detected into a frequency digital signal and send the frequency digital signal to the single chip microcomputer 38.
The setting key input circuit 33 is connected with the single chip microcomputer 38, and the setting key input circuit 33 is used for inputting the factory calibration coefficient of the vortex frequency signal detection part to the single chip microcomputer 38; the single chip microcomputer 38 is configured to calculate a mass flow rate of the gas to be measured according to the differential pressure digital signal, the frequency digital signal, and the factory calibration coefficient.
The mass flow rate DA conversion circuit 37 is connected to the single chip microcomputer 38, and the mass flow rate DA conversion circuit 37 is configured to convert the mass flow rate of the gas to be detected into a mass flow rate signal; the mass flow DA conversion circuit 37 also outputs a 4-20 mA instantaneous mass flow standard signal for a third party to use.
Specifically, the model of the single chip microcomputer 38 is MSP430F 5529. The singlechip 38 is solidified with a calculation program, calculates the real-time density of the gas through the solidified calculation program, and calculates the gas mass flow according to the real-time density, the real-time gas frequency and the instrument coefficient of the vortex frequency signal detection component. The calculation program calculates the gas mass flow according to the following formula:
wherein,
rho represents gas real-time density, k represents instrument coefficient, f represents vortex frequency signal of gas to be measured, alpha represents flow coefficient, delta P represents differential pressure signal of gas to be measured, q represents pressure difference signal of gas to be measured
mRepresenting the mass flow of the gas to be measured. Wherein, the instrument coefficient k and the flow coefficient alpha of the vortex frequency signal detection component are factory calibration coefficients.
The control calculation part 301 further includes a liquid Crystal display (lcd) display drive circuit 34. The LCD display driving circuit 34 is connected with the single chip microcomputer 38, and the LCD display driving circuit 34 is used for displaying the frequency digital signal, the differential pressure digital signal and the mass flow of the gas to be measured.
Example two
As shown in fig. 3, the present embodiment provides a gas mass flow measuring method according to the first embodiment, including:
step 1, acquiring a differential pressure signal of the gas to be detected output by a differential pressure signal detection part.
And 2, acquiring the vortex frequency signal of the gas to be detected output by the vortex frequency signal detection component.
And 3, calculating the gas mass flow of the gas to be measured according to the differential pressure signal and the vortex frequency signal. The step 3 specifically comprises the following steps:
according to the formula
And calculating the gas mass flow of the gas to be measured.
Wherein,
rho represents gas real-time density, k represents instrument coefficient, f represents vortex frequency signal of gas to be measured, alpha represents flow coefficient, delta P represents differential pressure signal of gas to be measured, q represents pressure difference signal of gas to be measured
mRepresenting the mass flow of the gas to be measured. Wherein, the instrument coefficient k and the flow coefficient alpha of the vortex frequency signal detection component are factory calibration coefficients.
EXAMPLE III
The field requirements of the embodiment in practical application are as follows: and measuring the gas supply quality of a certain natural gas conveying pipeline DN 100. The relevant parameters include: the natural gas conveying pipeline has the model number DN100, the medium pressure is 6.3MPa, and the temperature is normal temperature; the natural gas is mixed gas, the mass percent of methane is about 84.0123%, solar power is required to be supplied, and GPRS-4G signal data are wirelessly transmitted.
Equipment type selection: a DN100 novel gas mass flow computer DL310E-100-G1ML is selected and matched, and the meter coefficient K of a vortex street sensor (vortex frequency signal detection component) is 1005.95p/m after the detection by clean air3The actual flow of the flow coefficient α is designated 0.1972.
The gas mass flow measuring device provided by the embodiment is installed on a field pipeline, and if the LCD display screen displays that the differential pressure and the frequency value show slow wave-like changes, the density of the natural gas is described to be slowly wave-like changes, and the differential pressure and the frequency value at a certain moment are intercepted, wherein the differential pressure Δ P is 8.4479KPa, and the frequency f is 324.10 Hz.
Substituting the known values into the calculation formula:
the invention provides a gas mass flow measuring device and a method, which structurally integrates a vortex street flow sensor and a differential pressure flow sensor, wherein the vortex street flow sensor is used for detecting vortex frequency, the differential pressure sensor is used for calculating differential pressure, the two sensors work independently without influencing each other and are redundant mutually, the measurement continuity is realized, the differential pressure or gas frequency is obtained, and the measurement interruption caused by the absence of a redundant measurement scheme when a flowmeter is in fault is avoided, so that the production is greatly lost. In addition, the mass flow of the gas is calculated through the detected vortex frequency and the differential pressure signal, and the measurement of the mass flow of the gas is realized.
Compared with the prior art, the invention also has the following advantages:
(1) the invention arranges the vortex street flow sensor on the pipeline part through which the gas passes, compared with a differential pressure orifice plate flowmeter, the pressure loss of the pipeline is greatly reduced, and the invention is more beneficial to energy saving.
(2) When the invention adopts the vortex street sensor to measure the gas flow, the measuring range is much wider than that of differential pressure, and the pore plate is 1: 10, the wide-range vortex street is 1: 80, the application range and adaptability are stronger, and the stability is higher.
(3) The invention structurally integrates the vortex street flow sensor and the differential pressure flow sensor, the two flow sensors work independently without influencing each other and are mutually redundant, if a certain flow sensor fails and can not stop gas supply on site, the control and calculation part can automatically switch to the other flow sensor for basic metering through program judgment, thereby ensuring the continuity of metering.
(4) Compared with the traditional measurement of gas mass flow, the invention has the advantages that a temperature sensor, a pressure transmitter and a flow integrating instrument are omitted, so that the installation is more convenient, and the invention is lower in failure rate and more convenient to maintain on a special type overhead pipe gallery.
(5) The density of the gas measured by the invention is real density which changes in real time, and can be mixed gas, the components of the mixed gas are not needed to be known in advance, the working condition density of the mixed gas is directly measured in real time and participates in operation, and the calculated gas quality precision is higher.
(6) The invention combines the application of the modern network Internet of things technology to realize that signals can be transmitted randomly through wireless 4G and 5G networks. Meanwhile, the solar power supply equipment is configured, so that the application of places with inconvenient power supply is thoroughly solved.
(7) Compared with an inlet gas mass flowmeter, the invention has the advantages that the modern application technology functions are greatly increased, the cost is greatly reduced, the import price is about 40 ten thousand, and the price of the product is not more than 30 ten thousand.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.