WET GAS FLOW RATE METERING METHOD BASED ON A CORIOLIS MASS FLOWMETER AND DEVICE THEREOF
20220034697 · 2022-02-03
Assignee
Inventors
Cpc classification
International classification
Abstract
This application discloses a wet gas flow rate metering method and device thereof. The Coriolis mass flowmeter measures a total mass flow rate Q.sub.m, a mixed density ρ.sub.mix, and a medium temperature T; a combination of sensors measures a differential pressure ΔP between an inlet and an outlet; a flow rate calculation module performs multi-physical field coupling calculation to obtain an average gas density ρ.sub.g; according to the mixed density ρ.sub.mix, the average gas density ρ.sub.g, and a liquid density ρ.sub.l, a mass liquid content nm of a mixed medium is calculated, and the total mass flow rate Q.sub.m is corrected by the mass liquid content η.sub.m, the medium temperature T and the average pressure P to obtain a corrected total mass flow rate Q.sub.m′. According to the total mass flow rate Q.sub.m′ and the mass liquid content η.sub.m, a two-phase flow rate is calculated.
Claims
1. A wet gas flow rate metering method based on a Coriolis mass flowmeter, comprising the steps of: measuring, by a Coriolis mass flowmeter, a mass flow rate Q.sub.m, a mixed density ρ.sub.mix, a medium temperature T in a pipe; measuring, by a combination of sensors, a pressure P at an inlet and an outlet of the Coriolis mass flowmeter; performing, by a flow rate calculation module, a multi-physical field coupling calculation, calculating pressure P corresponding to different positions X in a measuring pipe of the Coriolis mass flowmeter, and generating a function curve between the position and the pressure; calculating, by the flow rate calculation module, an average pressure P in the measuring pipe of the Coriolis mass flowmeter through the function curve; calculating, by the flow rate calculation module, an average gas density ρ.sub.g according to the average pressure P; calculating, by the flow rate calculation module, a mass liquid content η.sub.m of a mixed medium according to the mixed density ρ.sub.mix, the average gas density ρ.sub.g and a liquid density ρ.sub.l, specifically comprising using a formula:
2. The wet gas flow rate metering method based on a Coriolis mass flowmeter according to claim 1, wherein the combination of sensors comprises a pressure sensor and a differential pressure sensor that by measuring the pressure at the inlet of the Coriolis mass flowmeter and measuring the differential pressure ΔP at the inlet and the outlet in combination with the mixed density ρ.sub.mix, obtain the average pressure in the measuring pipe of the Coriolis mass flowmeter through a computational fluid dynamics CFD model.
3. The wet gas flow rate metering method based on a Coriolis mass flowmeter according to claim 1, wherein the combination of sensors comprises two pressure sensors that by measuring the pressure at the inlet and the outlet of the Coriolis mass flowmeter to obtain an actual differential pressure ΔP in combination with the mixed density ρ.sub.mix, obtain the average pressure in the measuring pipe of the Coriolis mass flowmeter through a computational fluid dynamics CFD model.
4. The wet gas flow rate metering method based on a Coriolis mass flowmeter according to claim 1, wherein the step of calculating, by the flow rate calculation module an average pressure P in the measuring pipe of the Coriolis mass flowmeter through the function curve comprises: calculating by using a calculus area solving to obtain the average pressure P.
5. The wet gas flow rate metering method based on a Coriolis mass flowmeter according to claim 4, wherein the step of calculating, by the flow rate calculation module an average gas density ρ.sub.g according to the average pressure P comprises: using the pressure and the temperature in combination with a PVT equation of a gas phase medium, using a formula:
6. The wet gas flow rate metering method based on a Coriolis mass flowmeter according to claim 5, wherein in the step of correcting, by the flow rate calculation module the total mass flow rate Q.sub.m according to the mass liquid content η.sub.m, the average pressure P in the measuring pipe and the medium temperature T to obtain a total mass flow rate Q.sub.m′, a specific correction formula is that Q.sub.m′=f(P,T,η.sub.m,Q.sub.m).
7. The wet gas flow rate metering method based on a Coriolis mass flowmeter according to claim 6, wherein the step of calculating, by the flow rate calculation module a gas mass flow rate Q.sub.g and a liquid mass flow rate Q.sub.l according to the mass liquid content η.sub.m and the total mass flow rate Q.sub.m′ comprises: using a formula Q.sub.g=Q.sub.m′*(1−η.sub.m) to calculate the gas mass flow rate Q.sub.g; using a formula Q.sub.l=Q.sub.m′*η.sub.m to calculate the liquid mass flow rate Q.sub.l.
8. A wet gas flow rate metering device based on a Coriolis mass flowmeter, comprising a Coriolis mass flowmeter, and further comprising a pipe, a flow rate calculation module and a combination of sensors that is mounted on the pipe, wherein: the pipe is for transferring the wet gas; the combination of sensors is for measuring a differential pressure ΔP at an inlet and an outlet in the pipe; the flow rate calculation module performs a multi-physical field coupling calculation, calculates pressure P corresponding to different positions X in a measuring pipe of the Coriolis mass flowmeter, and generates a function curve between the position and the pressure; the flow rate calculation module calculates an average pressure P in the measuring pipe of the Coriolis mass flowmeter through the function curve; calculates an average gas density ρ.sub.g according to the average pressure P; then calculates a mass liquid content η.sub.m of a mixed medium according to the mixed density ρ.sub.mix, the average gas density ρ.sub.g and a liquid density ρ.sub.l, wherein the liquid density ρ.sub.l is a constant, specifically comprising: using a formula:
9. The wet gas flow rate metering device based on a Coriolis mass flowmeter according to claim 8, wherein the combination of sensors comprises a pressure sensor and a differential pressure sensor that by measuring the pressure at the inlet of the Coriolis mass flowmeter and measuring the differential pressure ΔP at the inlet and the outlet in combination with the mixed density ρ.sub.mix, obtain the average pressure in the measuring pipe of the Coriolis mass flowmeter through a computational fluid dynamics CFD model.
10. The wet gas flow rate metering device based on a Coriolis mass flowmeter according to claim 8, wherein the combination of sensors comprises two pressure sensors that by measuring the pressure at the inlet and the outlet of the Coriolis mass flowmeter to obtain an actual differential pressure ΔP in combination with the mixed density ρ.sub.mix, obtain the average pressure in the measuring pipe of the Coriolis mass flowmeter through a computational fluid dynamics CFD model.
11. The wet gas flow rate metering device based on a Coriolis mass flowmeter according to claim 8, wherein the step of calculating, by the flow rate calculation module an average pressure P in the measuring pipe of the Coriolis mass flowmeter through the function curve comprises: calculating by using a calculus area solving to obtain the average pressure P.
12. The wet gas flow rate metering device based on a Coriolis mass flowmeter according to claim 11, wherein the flow rate calculation module, according to the pressure and the temperature in combination with a PVT equation of a gas phase medium, uses a formula:
13. The wet gas flow rate metering device based on a Coriolis mass flowmeter according to claim 12, wherein when the flow rate calculation module corrects the total mass flow rate Q.sub.m according to the mass liquid content η.sub.m, the average pressure P in the measuring pipe and the medium temperature T to obtain a total mass flow rate Q.sub.m′, a specific correction formula is that Q.sub.m′=f(P,T,η.sub.m,Q.sub.m).
14. The wet gas flow rate metering device based on a Coriolis mass flowmeter according to claim 13, wherein the flow rate calculation module specifically uses a formula Q.sub.g=Q.sub.m′*(1−q.sub.m) to calculate the gas mass flow rate Q.sub.g, and uses a formula Q.sub.l=Q.sub.m′*η.sub.m to calculate the liquid mass flow rate Q.sub.l.
15. The wet gas flow rate metering device based on a Coriolis mass flowmeter according to claim 8, wherein a temperature sensor is provided within a casing of the Coriolis mass flowmeter, and the temperature sensor is attached to the measuring pipe of the Coriolis mass flowmeter.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF THE EMBODIMENTS
[0044] The application is described in detail below with reference to the accompanying drawings and examples.
[0045] A wet gas flow rate metering method based on a Coriolis mass flowmeter includes the following specific metering methods:
[0046] A Coriolis mass flowmeter 1 measures a mass flow rate Q.sub.m, a mixed density ρ.sub.mix, a medium temperature T in a pipe.
[0047] Referring to
[0048] As shown in
[0049] It should be noted that the above two sensor modes can achieve the purpose of measurement, and in the specific implementation process, the actual differential pressure ΔP can also be measured by other sensors in different combinations.
[0050] The flow rate calculation module performs a multi-physical field coupling calculation, calculates pressure P corresponding to different positions X in a measuring pipe of the Coriolis mass flowmeter, and generates a function curve between the position and the pressure (see
[0051] The flow rate calculation module calculates the average pressure P in the measuring pipe of the Coriolis mass flowmeter by combining the function curve with a calculus area solving mode.
[0052] The flow rate calculation module combines the PVT equation of the gas-phase medium and the gas state equation according to the pressure P at different positions: PV=εnRT. It can be seen that the gas density ρ.sub.g is proportional to the pressure P and inversely proportional to the temperature T. It follows that the measurement of pressure and temperature is necessary and is a key quantity for obtaining the gas density, assuming that irrespective of the influence of the temperature field, when the pressure P varies, the volume V changes accordingly;
[0053] using the formula:
to finally obtain the average gas density ρ.sub.g.
[0054] calculating the gas density ρ.sub.g, where P, T are the pressure and the absolute temperature in the measuring pipe of the Coriolis mass flowmeter respectively, ρ.sub.0, P.sub.0 and T.sub.0 are the gas density, the pressure and the absolute temperature in a calibration state respectively.
[0055] The flow rate calculation module calculates a mass liquid content η.sub.m of a mixed medium according to the mixed density ρ.sub.mix, the average gas density ρ.sub.g and a liquid density ρ.sub.l by using the formula:
[0056] in the step that the flow rate calculation module corrects the total mass flow rate Q.sub.m according to the mass liquid content η.sub.m, the average pressure P in the measuring pipe and the medium temperature T to obtain a total mass flow rate Q.sub.m′, and the specific correction formula is that:
Q.sub.m′=f(P,T,η.sub.m,Q.sub.m).
[0057] In the actual calculation process, the data of a plurality of discrete point positions are measured through the flow rate calculation module, and an accurate calculation function is obtained through generating a function curve through the data of a plurality of groups of discrete point positions. Since the mass liquid content η.sub.m has a strong influence on the total mass flow rate Q.sub.m while the temperature T has a weak influence on the total mass flow rate Q.sub.m, assuming that irrespective of the influence of the temperature T on the total mass flow rate Q.sub.m, a function curve between the flow rate magnification and the mass liquid content is shown in
[0058] The flow rate calculation module calculates the corrected total mass flow rate Q.sub.m′ through the function curve in combination with a curve equation.
[0059] the flow rate calculation module calculates a gas mass flow rate Q.sub.g and a liquid mass flow rate Q.sub.l according to the mass liquid content η.sub.m and the total mass flow rate Q.sub.m′; uses a formula Q.sub.g=Q.sub.m′*(1−η.sub.m) to calculate the gas mass flow rate Q.sub.g; and uses a formula Q.sub.l=Q.sub.m′*η.sub.m to calculate the liquid mass flow rate Q.sub.l.
[0060] According to the wet gas flow rate metering method provided by the embodiment of the application, the total mass flow rate Q.sub.m, the mixed density ρ.sub.mix and the medium temperature T are measured through the Coriolis mass flowmeter; the combination of sensors measures the pressure difference ΔP at the inlet and the outlet, and in combination with the mixed density ρ.sub.mix to obtain the average pressure P in the measuring pipe of the Coriolis mass flowmeter through a computational fluid dynamics CFD model. The flow rate calculation module performs a multi-physical field coupling calculation, calculates pressure P corresponding to different positions X in a measuring pipe of the Coriolis mass flowmeter, and generates a function curve between the position and the pressure. The flow rate calculation module calculates an average pressure P in the measuring pipe of the Coriolis mass flowmeter through the function curve in combination with a calculus area solving mode; and calculates the average gas density ρ.sub.g by combining the average pressure P with the PVT equation; the flow rate calculation module calculates a mass liquid content η.sub.m of a mixed medium according to the mixed density ρ.sub.mix, the average gas density ρ.sub.g and a liquid density ρ.sub.l which default is a constant; corrects the total mass flow rate Q.sub.m according to the mass liquid content η.sub.m of the mixed medium to obtain a corrected total mass flow rate Q.sub.m′; and finally, calculates a gas mass flow rate Q.sub.g and a liquid mass flow rate Q.sub.l according to the total mass flow rate Q.sub.m′ and the mass liquid content η.sub.m.
[0061] Data measurement is carried out through a single Coriolis mass flowmeter in combination with the multi-physical field coupling calculation, calculating to obtain accurate average pressure P, further correcting the gas density ρ.sub.g, and calculating to obtain an accurate mass liquid content η.sub.m and the total mass flow rate Q.sub.m′ conforming to the actual situation according to the gas density ρ.sub.g, under the actual working condition, and finally calculating to obtain the gas-liquid two-phase flow rate. The data obtained by the wet gas flow rate metering method and device has higher accuracy.
[0062] It is further noted here that the total mass flow rate Q.sub.m in this embodiment is directly measured and calculated by the Coriolis mass flowmeter, however, a person skilled in the art may also obtain the total mass flow rate Q.sub.m through other means. For example: a wet gas meter based on resonance and differential pressure measurements may be used. Firstly, a differential pressure ΔP between the inlet and the outlet of the measuring pipe is measured by a sensor, and using the formula: Q.sub.m=A √{square root over (ΔP*p mix)} to calculate and obtain the total mass flow rate Q.sub.m, where A is a system parameter, ΔP is the differential pressure between the inlet and the outlet of the measuring pipe, and ρ.sub.mix is a mixed density of the medium.
[0063] After calculating and obtaining the total mass flow rate Q.sub.m, the subsequent measuring and calculating of the data adopt the same correction mode as above.
[0064] With reference to
[0065] the pipe is for transferring the wet gas;
[0066] the combination of sensors is for measuring a differential pressure ΔP at the inlet 6 and the outlet 7 in the pipe;
[0067] the flow rate calculation module performs a multi-physical field coupling calculation, calculates pressure P corresponding to different positions X in a measuring pipe of the Coriolis mass flowmeter, and generates a function curve between the position and the pressure; the flow rate calculation module calculates an average pressure P in the measuring pipe of the Coriolis mass flowmeter through the function curve; calculates an average gas density ρ.sub.g according to the average pressure P; then calculates a mass liquid content η.sub.m of a mixed medium according to the mixed density ρ.sub.mix, the average gas density ρ.sub.g and a liquid density ρ.sub.l (a constant); the flow rate calculation module corrects the total mass flow rate Q.sub.m according to the mass liquid content η.sub.m, the average pressure P in the measuring pipe and the medium temperature T to obtain a total mass flow rate Q.sub.m′; finally, the flow rate calculation module calculates a gas mass flow rate Q.sub.g and a liquid mass flow rate Q.sub.l according to the mass liquid content η.sub.m and the total mass flow rate Q.sub.m′.
[0068] In some embodiments, as shown in
[0069] In some embodiments, as shown in
[0070] It should be noted that the above two sensor modes can achieve the purpose of measurement, and in the specific implementation process, the actual differential pressure ΔP can also be measured by other sensors in different combinations.
[0071] In some embodiments, the flow rate calculation module combines the PVT equation of the gas-phase medium and the gas state equation according to the pressure and temperature: PV=εnRT. It can be seen that the gas density ρ.sub.g is proportional to the pressure P and inversely proportional to the temperature T. It follows that the measurement of pressure and temperature is necessary and is a key quantity for obtaining the gas density, assuming that irrespective of the influence of the temperature field, when the pressure P varies, the volume V changes accordingly; using the formula:
to finally obtain the average gas density ρ.sub.g.
[0072] calculating the gas density ρ.sub.g, where P, T are the pressure and the absolute temperature in the measuring pipe of the Coriolis mass flowmeter respectively, ρ.sub.0, P.sub.0 and T.sub.0 are the gas density, the pressure and the absolute temperature in a calibration state respectively.
[0073] In some embodiments, the flow rate calculation module specifically uses a formula:
[0074] to calculate a mass liquid content η.sub.m of a mixed medium, where ρ.sub.mix is the mixed density, ρ.sub.g is the average gas density, and ρ.sub.l is a liquid density.
[0075] In some embodiments, in the step that the flow rate calculation module corrects the total mass flow rate Q.sub.m according to the mass liquid content η.sub.m, the average pressure P in the measuring pipe and the medium temperature T to obtain a total mass flow rate Q.sub.m′, and the specific correction formula is that:
Q.sub.m′=f(P,T,η.sub.m,Q.sub.m);
[0076] In the actual calculation process, the data of a plurality of discrete point positions are measured through the flow rate calculation module, and an accurate calculation function is obtained through generating a function curve through the data of a plurality of groups of discrete point positions. Since the mass liquid content η.sub.m has a strong influence on the total mass flow rate Q.sub.m while the temperature T has a weak influence on the total mass flow rate Q.sub.m, assuming that irrespective of the influence of the temperature T on the total mass flow rate Q.sub.m, a function curve between the flow rate magnification and the mass liquid content is shown in
[0077] The flow rate calculation module calculates the corrected total mass flow rate Q.sub.m′ through the function curve in combination with a curve equation.
[0078] In some embodiments, the flow rate calculation module specifically uses a formula Q.sub.g=Q.sub.m′*(1−η.sub.m) to calculate the gas mass flow rate Q.sub.g; and uses a formula Q.sub.l=Q.sub.m′*η.sub.m to calculate the liquid mass flow rate Q.sub.l.
[0079] In some embodiments, a temperature sensor is provided within a casing of the Coriolis mass flowmeter, and the temperature sensor is attached to the measuring pipe of the Coriolis mass flowmeter. The temperature sensor synchronously vibrates with the measuring pipe, so that the temperature of the medium can be accurately reflected.
[0080] According to the wet gas flow rate metering device provided by the embodiment of the application, the total mass flow rate Q.sub.m, the mixed density ρ.sub.mix and the medium temperature T are measured through the Coriolis mass flowmeter; the combination of sensors measures the pressure difference ΔP at the inlet and the outlet, and in combination with the mixed density ρ.sub.mix to obtain the average pressure P in the measuring pipe of the Coriolis mass flowmeter through a computational fluid dynamics CFD model. The flow rate calculation module performs a multi-physical field coupling calculation, calculates pressure P corresponding to different positions X in a measuring pipe of the Coriolis mass flowmeter, and generates a function curve between the position and the pressure. The flow rate calculation module calculates an average pressure P in the measuring pipe of the Coriolis mass flowmeter through the function curve in combination with a calculus area solving mode; and calculates the average gas density ρ.sub.g by combining the average pressure P with the PVT equation; the flow rate calculation module calculates a mass liquid content η.sub.m of a mixed medium according to the mixed density ρ.sub.mix, the average gas density ρ.sub.g and a liquid density ρ.sub.l which default is a constant; corrects the total mass flow rate Q.sub.m according to the mass liquid content η.sub.m of the mixed medium to obtain a corrected total mass flow rate Q.sub.m′; and finally, calculates a gas mass flow rate Q.sub.g and a liquid mass flow rate Q.sub.l according to the total mass flow rate Q.sub.m′ and the mass liquid content η.sub.m.
[0081] Data measurement is carried out through a single Coriolis mass flowmeter in combination with the multi-physical field coupling calculation, calculating to obtain accurate average pressure P, further correcting the gas density ρ.sub.g, and calculating to obtain an accurate mass liquid content η.sub.m and the total mass flow rate Q.sub.m′ conforming to the actual situation according to the gas density ρ.sub.g, under the actual working condition, and finally calculating to obtain the gas-liquid two-phase flow rate. The data obtained by the wet gas flow rate metering method and device has higher accuracy.
[0082] A series of experiments are carried out by using the wet gas flow rate metering device, which shows the influence of the mass liquid content η.sub.m on the total mass flow rate Q.sub.m. See
[0083] To further prove the data measurement accuracy of the wet gas metering device of the present embodiment,
[0084] According to the experimental data, the data which is not corrected has larger difference with the actual working condition data, while the difference between the corrected data and the actual working condition data is smaller. It can be seen that the effectiveness of multi-physic filed coupling correction.
[0085] The above descriptions are only preferred embodiments of the present application, and the protection scope of the present application is not limited to the above embodiments, and all technical solutions belonging to the idea of the present application belong to the protection scope of the present application. It should be noted that modifications and embellishments within the scope of the application may occur to those skilled in the art without departing from the principle of the application, and are considered to be within the scope of the application.