CN109085083B - Method and system for acquiring methane absorption ratio and terminal equipment - Google Patents
Method and system for acquiring methane absorption ratio and terminal equipment Download PDFInfo
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Abstract
The invention is suitable for the technical field of unconventional natural gas, and discloses a method, a system and terminal equipment for acquiring a methane absorption ratio, wherein the method comprises the following steps: acquiring experimental data of a methane isothermal adsorption experiment; acquiring the concentration of free methane at a first moment, wherein the first moment is any moment in the methane adsorption process; respectively obtaining the mass of first adsorbed methane and the total mass of first methane in the sample at the first moment according to the concentration of free methane and experimental data at the first moment, wherein the total mass of first methane is the total mass of adsorbed methane and free methane in the sample at the first moment; and obtaining the methane absorption ratio at the first moment according to the mass of the methane in the first adsorption state and the total mass of the first methane. According to the method, each parameter of the methane desorption ratio is calculated based on experimental determination, and disturbance and influence of uncontrollable factors in engineering are avoided, so that the calculation result of the methane desorption ratio is more accurate, and the methane desorption ratio can be obtained without directly calculating the free methane mass in a sample.
Description
Technical Field
The invention belongs to the technical field of unconventional natural gas, and particularly relates to a method and a system for acquiring a methane absorption ratio and terminal equipment.
Background
With the rapid development of economy, the demand for natural gas in countries around the world has seen explosive growth. Conventional natural gas production has failed to meet current demand, and thus unconventional natural gas has become a trend in natural gas development as an important supplement to energy production. The natural gas occurrence state in the reservoir mainly includes three states of adsorption state, free state and dissolution state. Conventional natural gas is mainly free gas, while unconventional natural gas such as shale gas, coal bed gas and the like has a condition in a reservoir mainly comprising adsorbed gas and free gas, and a small amount of dissolved gas, and the total gas content mainly depends on the free gas content and the adsorbed gas content. The free gas absorption ratio is the ratio of the free gas content to the absorbed gas content, is an important parameter of the unconventional natural gas containing structure, and is a key factor influencing the gas production rate and the recovery rate of the unconventional natural gas.
At present, the method for obtaining the aspiration ratio usually obtains the adsorption gas amount and the free gas amount indirectly according to engineering data, and then calculates the aspiration ratio according to the adsorption gas amount and the free gas amount. However, due to more uncontrollable factors in engineering, the method is easily disturbed and influenced by the uncontrollable factors in engineering, so that the obtained air suction ratio is inaccurate.
Disclosure of Invention
In view of this, embodiments of the present invention provide a method, a system, and a terminal device for obtaining a methane desorption ratio, so as to solve the problem in the prior art that the obtained methane desorption ratio is inaccurate due to disturbance and influence of uncontrollable factors in engineering.
The first aspect of the embodiments of the present invention provides a method for obtaining a methane free absorption ratio, including:
acquiring experimental data of a methane isothermal adsorption experiment;
acquiring the concentration of free methane at a first moment, wherein the first moment is any moment in the methane adsorption process;
respectively obtaining the mass of first adsorbed methane and the total mass of first methane in the sample at the first moment according to the concentration of free methane and experimental data at the first moment, wherein the total mass of first methane is the total mass of adsorbed methane and free methane in the sample at the first moment;
and obtaining the methane absorption ratio at the first moment according to the mass of the methane in the first adsorption state and the total mass of the first methane.
A second aspect of an embodiment of the present invention provides a system for obtaining a methane absorption ratio, including:
the experimental data acquisition module is used for acquiring experimental data of the methane isothermal adsorption experiment;
the first methane concentration acquisition module is used for acquiring the free methane concentration at a first moment, wherein the first moment is any moment in the methane adsorption process;
the first methane quality acquisition module is used for respectively acquiring the first adsorption methane quality and the first total methane quality in the sample at the first moment according to the free methane concentration and the experimental data at the first moment, wherein the first total methane quality is the adsorption methane quality and the free methane quality in the sample at the first moment;
and the first absorption ratio acquisition module is used for acquiring the methane absorption ratio at the first moment according to the first adsorption state methane mass and the first methane total mass.
A third aspect of the embodiments of the present invention provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the steps of the method for acquiring a methane absorption ratio as described above when executing the computer program.
A fourth aspect of embodiments of the present invention provides a computer-readable storage medium, which stores a computer program, which, when executed by one or more processors, implements the steps of the method for obtaining a methane upstream absorption ratio as described above.
Compared with the prior art, the embodiment of the invention has the following beneficial effects: according to the embodiment of the invention, the first adsorption state methane mass and the first methane total mass in the sample at the first moment are respectively obtained according to the free state methane concentration at the first moment and the experimental data of the methane isothermal adsorption experiment, wherein the first moment is any moment in the methane adsorption process, and the methane adsorption ratio at the first moment is obtained according to the first adsorption state methane mass and the first methane total mass.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
FIG. 1 is a schematic diagram of a device for obtaining a methane absorption ratio according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart of an implementation of a method for obtaining a methane absorption ratio according to an embodiment of the present invention;
FIG. 3 is a schematic flow chart of an implementation of a method for obtaining a methane absorption ratio according to another embodiment of the present invention;
FIG. 4 is a schematic flow chart of an implementation of a method for obtaining a methane absorption ratio according to another embodiment of the present invention;
FIG. 5 is a schematic flow chart of an implementation of a method for obtaining a methane absorption ratio according to another embodiment of the present invention;
FIG. 6 is a schematic block diagram of a system for obtaining a methane absorption ratio according to an embodiment of the present invention;
fig. 7 is a schematic block diagram of a terminal device according to an embodiment of the present invention.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It is also to be understood that the terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of the present application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.
As used in this specification and the appended claims, the term "if" may be interpreted contextually as "when", "upon" or "in response to a determination" or "in response to a detection". Similarly, the phrase "if it is determined" or "if a [ described condition or event ] is detected" may be interpreted contextually to mean "upon determining" or "in response to determining" or "upon detecting [ described condition or event ]" or "in response to detecting [ described condition or event ]".
In order to explain the technical means of the present invention, the following description will be given by way of specific examples.
Fig. 1 is a schematic diagram of an apparatus for obtaining a methane free absorption ratio according to an embodiment of the present invention, as shown in fig. 1, the apparatus may include: the device comprises a temperature and pressure control device 1, a laser emitter 2, a gas tank 3, a gas flow rate control device 4, a sample room 5, a laser detection and signal conversion device 6 and a terminal device 7.
First, the sample chamber 5 and sample are calibrated and measured, including calibrating the sample chamber volume, sample chamber length (i.e., the length of the sample chamber through which the laser passes), sample mass, sample density, and helium gas measurement sample porosity. The ratio of sample mass to sample density is the sample volume, and the product of the sample volume and the helium measured sample porosity is the sample pore volume. The sample is a shale sample or a coal rock sample, can be a regular or irregular block sample, and can also be rock debris or powder with a certain particle size. The sample chamber 5 may be a thermostated sample chamber. The helium gas is used for measuring the porosity of the sample, namely the porosity of the sample by a helium gas method, and the specific reference can be made to GB/T34533-2017 for measuring the porosity of the sample by an industry standard shale helium gas method and the permeability of a pulse attenuation method.
Specifically, the sample is placed in the sample chamber 5, and the sample chamber 5 is purged with high-purity nitrogen gas and then evacuated. And starting the temperature and pressure control equipment 1, setting the experiment temperature, measuring the gas pressure in the methane adsorption process in real time, and recording the change of the pressure along with the time. Debugging the laser emitter 2, checking whether the laser emitter 2 runs well, and setting the laser emitter 2 to be in an open state after debugging. The flow rate of methane into the sample chamber 5 is set at the gas flow rate control device 4 and the flow of gas therethrough can be displayed in real time by the gas flow rate control device 4. The gas tank 3 containing high purity methane is opened and methane gas enters the sample chamber 5. The laser is absorbed by the gas in the sample chamber 5, received by the laser detection and signal conversion device 6 and transmitted to the terminal device 7. The terminal device 7 can obtain the free methane concentration in real time according to the received data.
Fig. 2 is a schematic flow chart of an implementation of the method for obtaining the methane absorption rate according to an embodiment of the present invention, and for convenience of description, only the portion related to the embodiment of the present invention is shown. The execution main body of the embodiment of the invention can be terminal equipment. As shown in fig. 2, the method may include the steps of:
step S201: and acquiring experimental data of the methane isothermal adsorption experiment.
The embodiment of the invention obtains the methane free absorption ratio in the sample through a methane isothermal adsorption experiment. The experimental data may include one or more of sample chamber volume, sample mass, sample pore volume, methane mass at a first time in the sample chamber, methane mass at a second time in the sample chamber, experimental temperature, optical path length, experimental pressure at the first time, and the like. Wherein the first moment is any moment in the methane adsorption process; the second moment is the moment of methane adsorption saturation; the mass of methane in the sample chamber at the first moment is the mass of methane flowing into the sample chamber 5 in the time from the moment of opening the gas tank 3 to the first moment, i.e. the flow rate multiplied by the time; the mass of methane in the sample chamber at the second moment is the mass of methane flowing into the sample chamber 5 in the time period from the moment of opening the gas tank 3 to the second moment, i.e. the flow rate is multiplied by the time; the experimental temperature is set in the sample chamber; the optical path length can be obtained according to the length of the sample chamber; the experimental pressure at the first moment may be measured by the constant temperature pressure measuring device 2.
Step S202: and acquiring the concentration of the free methane at the first moment, wherein the first moment is any moment in the methane adsorption process.
The embodiment of the invention calculates the methane adsorption ratio in the methane adsorption process, and firstly obtains the free methane concentration at the first moment, wherein the first moment is any moment in the methane adsorption process.
Step S203: and respectively obtaining the first adsorption state methane mass and the first total methane mass in the sample at the first moment according to the concentration of the free state methane and the experimental data at the first moment, wherein the first total methane mass is the adsorption state methane mass and the free state methane mass in the sample at the first moment.
In the embodiment of the present invention, as the isothermal methane adsorption experiment proceeds, a part of the free methane flowing in through the gas tank 3 is adsorbed on the sample and converted into adsorbed methane. In order to calculate the methane desorption ratio at the first moment, the adsorbed methane mass (i.e. the first adsorbed methane mass) in the sample at the first moment and the total adsorbed and free methane mass (i.e. the first total methane mass) in the sample at the first moment are calculated according to the free methane concentration at the first moment and experimental data.
Step S204: and obtaining the methane absorption ratio at the first moment according to the mass of the methane in the first adsorption state and the total mass of the first methane.
As another embodiment of the present invention, the formula for obtaining the methane absorption ratio at the first moment according to the mass of the methane in the first adsorption state and the total mass of the first methane is as follows:
wherein R isfree/adIs the methane free absorption ratio at the first moment, mad+freeIs the total mass of the first methane, madIs the first adsorption state methane mass.
In the formula (1), mad+freeAnd madThe units of (A) are all mg.
As can be seen from the above description, in the embodiment of the present invention, the first adsorbed methane mass and the first total methane mass in the sample at the first time are obtained according to the free methane concentration at the first time and the experimental data of the isothermal methane adsorption experiment, where the first time is any time in the methane adsorption process, and the methane adsorption ratio at the first time is obtained according to the first adsorbed methane mass and the first total methane mass, and the parameters of the methane adsorption ratio are calculated based on the experimental determination in the embodiment of the present invention, so that the disturbance and the influence of the uncontrollable factors in the engineering are avoided, and thus the calculation result of the methane adsorption ratio is more accurate, and the methane adsorption ratio can be obtained without directly calculating the free methane mass in the sample, and the embodiment of the present invention can realize the real-time calculation of the methane adsorption ratio in the methane adsorption process, so as to obtain the variation rule of the methane adsorption ratio in the sample, and (3) drawing the methane absorption ratio obtained at different moments into a relation graph of time-methane absorption ratio, namely analyzing the change rule of the methane absorption ratio in the methane adsorption process.
Fig. 3 is a schematic flow chart of an implementation of a method for obtaining a methane free absorption ratio according to another embodiment of the present invention. On the basis of the above embodiments, the experimental data includes the sample chamber volume, the sample pore volume, and the methane mass in the sample chamber at the first moment; as shown in fig. 3, step S203 may include the steps of:
step S301: the free methane volume is obtained from the sample chamber volume, the sample volume and the sample pore volume.
In the embodiment of the invention, the calculation formula for obtaining the free methane volume according to the sample chamber volume, the sample volume and the sample pore volume is as follows:
Vfree＝V0-V1+V2(2)
in the formula (2), VfreeVolume of methane in free form in m L V0Is the sample chamber volume in m L V1Is the sample volume in m L V2The unit is m L for the sample pore volume.
Step S302: and obtaining the first adsorption state methane quality according to the free state methane concentration at the first moment, the free state methane volume and the first moment methane quality.
In the embodiment of the present invention, the calculation formula for obtaining the first adsorbed methane mass according to the free methane concentration at the first time, the free methane volume and the first methane mass at the first time is as follows:
mad＝mg-w1×Vfree(3)
in the formula (3), mgThe mass of methane at the first moment is in mg; w is a1Is the free methane concentration at the first time in mg/m L.
Step S303: and obtaining the first total methane mass according to the free methane concentration at the first moment, the methane mass at the first moment, the sample chamber volume and the sample volume.
In the embodiment of the present invention, the calculation formula for obtaining the total mass of the first methane according to the free methane concentration at the first time, the methane mass at the first time, the sample chamber volume and the sample volume is as follows:
mad+free＝mg-w1×(V0-V1) (4)
fig. 4 is a schematic flow chart of an implementation of a method for obtaining a methane adsorption ratio according to another embodiment of the present invention, where based on the above embodiment, the experimental data includes a sample chamber volume, a sample mass, and a methane mass in the sample chamber at a second time, where the second time is a time at which methane adsorption is saturated; as shown in fig. 4, the method for obtaining the methane absorption ratio may further include the following steps:
step S401: and acquiring the free methane concentration at the second moment.
In the methane isothermal adsorption experiment, the methane adsorbed in the sample is gradually saturated with the passage of time, and the time at which the methane adsorption is saturated is taken as the second time.
In an embodiment of the present invention, the experimental data may further include an experimental temperature, an optical path length, and an experimental pressure at the second time.
The obtaining of the free methane concentration at the second moment specifically comprises: acquiring an absorbance curve of the methane at the second moment, and integrating the absorbance curve of the methane at the second moment on a frequency domain to obtain a second integral area; obtaining the absorption strength of gas molecular transition according to the experiment temperature; and obtaining the concentration of the free methane at the second moment according to the second integral area, the absorption intensity of the gas molecular transition, the optical path length and the experimental pressure at the second moment. The specific process can refer to the description of the embodiment shown in fig. 5.
Step S402: and acquiring the excessive adsorption amount at the second moment, and acquiring the absolute adsorption amount at the second moment according to the excessive adsorption amount.
In the methane isothermal adsorption experiment, the excessive adsorption amount at the second moment can be directly obtained.
L angmumir adsorption model is widely used for describing the adsorption behavior of methane in shale, and the calculation formula of the excess adsorption amount at the second moment can be obtained according to L angmumir equation and Gibbs equation as follows:
in the formula (5), nexcessThe unit of the excess adsorption capacity at the second moment is mmol/g; n is0The maximum adsorption quantity of methane at the experimental temperature is expressed in mmol/g; pLIs the Lange pressure in MPa; p2The experimental pressure at the second moment is in MPa; rhogIs the density of free methane at the second moment in units of g/m L, rhoadThe adsorbed methane density at the second moment in time is given in g/m L.
Wherein n is0And PLThe two parameters in L angmuir equation are obtained by a series of pressures and corresponding absorptions obtained by methane isothermal adsorption experimentThe specific operation can refer to a high-pressure isothermal adsorption test method GB/T19560-.
The calculation formula of the absolute adsorption amount at the second time is:
in the formula (6), nabsThe absolute adsorption amount at the second time is in mmol/g.
Step S403: and obtaining the second adsorption state methane mass in the sample at the second moment according to the absolute adsorption quantity and the sample mass.
In the embodiment of the present invention, the calculation formula for obtaining the second adsorption methane mass in the sample at the second time according to the absolute adsorption amount and the sample mass is as follows:
m 'of formula (7)'adThe mass of methane in the second adsorption state is mg;
is the molar mass of methane, in g/mol; m is1Is the sample mass in g.
Step S404: and obtaining the total mass of the second methane according to the concentration of the free methane at the second moment, the mass of the methane at the second moment, the volume of the sample chamber and the volume of the sample, wherein the total mass of the second methane is the total mass of the adsorbed methane and the free methane in the sample at the second moment.
In the embodiment of the present invention, the calculation formula for obtaining the total mass of the second methane according to the free methane concentration at the second time, the methane mass at the second time, the sample chamber volume and the sample volume is as follows:
m′ad+free＝m′g-w2×(V0-V1) (8)
m 'of formula (8)'ad+freeThe total mass of the second methane is mg; m'gThe mass of methane at the second moment is in mg; w is a2Is the free methane concentration at the second time in mg/m L.
Step S405: and obtaining the methane absorption ratio at the second moment according to the mass of the second adsorption methane and the total mass of the second methane.
In the embodiment of the present invention, the calculation formula for obtaining the methane desorption ratio at the second time according to the second adsorption methane mass and the second methane total mass is as follows:
r 'in the formula (9)'free/adThe methane absorption ratio at the second moment.
From the above description, it can be seen that the embodiment of the present invention corrects the experimental error caused by the adsorption volume in the equilibrium state of the high-pressure section, and improves the accuracy of the calculation of the methane free-adsorption ratio at the second time.
Fig. 5 is a schematic flow chart of an implementation of a method for obtaining a methane absorption ratio according to yet another embodiment of the present invention, where experimental data includes an experimental temperature, an optical path length, and an experimental pressure at a first time on the basis of the above embodiment; as shown in fig. 5, step S202 may include the steps of:
step S501: and acquiring an absorbance curve of the methane at the first moment, and integrating the absorbance curve of the methane at the first moment on a frequency domain to obtain a first integral area.
In the embodiment of the invention, the free methane concentration is obtained based on a Tunable laser absorption spectroscopy (TD L AS) technology, and the first task of obtaining the methane concentration by the Tunable laser absorption spectroscopy technology is to select the methane with high spectral line intensity and weak interference of other gas spectral line intensitiesConsidering economic factors, the wavelengths of semiconductor laser emitters with low cost and convenient carrying are all in the near infrared region, and according to the methane absorption spectrum of the information of a HITRAN database in the near infrared region, three strong absorption spectral lines are arranged near the wavelength of 1.653um, and the total intensity S after the three lines are combined is 1.26 × 10-20cm < -1 >/(mol x cm < -1 >)-2) (ii) a Research shows that under the condition that the temperature is 296K, the area with the strongest methane absorption is 1600-1700 nm, and the interference gas H at the moment2O and CO2Very weak and at 1653.72nm, the application selects a spectrum in the 1653.72nm wavelength band to obtain free methane density.
Step S502: and obtaining the absorption strength of the gas molecular transition according to the experimental temperature.
The absorption intensity of the gas molecular transition is determined with the experimental temperature determination.
Step S503: and obtaining the free methane concentration at the first moment according to the first integral area, the absorption intensity of the gas molecular transition, the optical path length and the experimental pressure at the first moment.
The basic principle of tunable laser absorption spectroscopy is the lambert-Beer (Beer-L ambert) law, namely:
in the formula (10), I0(v) The initial light intensity of the laser with the frequency v passing through a certain medium, I (v) the absorbed light intensity of the laser with the frequency v passing through a certain medium, k (v) the unit length absorption coefficient of gas with the frequency v, the calculation formula is formula (11), and L is the optical path length.
k(v)＝P1×w1×S(T)×Φi(v) (11)
In the formula (11), P1Is the experimental pressure at the first moment; s (T) is the absorption strength of gas molecular transition under the experimental temperature T; phii(v) Is a linear function.
In practice, the units cm/mol of S (T) are often convertedIs cm-2·atm-1As shown in formula (12).
In the formula (12), P is a gas pressure, V is a gas volume, N is a gas mole number, T is an experimental temperature, and each parenthesis represents a unit of each parameter.
Although the linear function is more complex to calculate, its integral in the whole frequency domain is constant to 1, as shown in equation (13).
∫Φi(v)di＝1 (13)
The first integrated area A is obtained from the expressions (10) to (13)1Comprises the following steps:
thus, the free methane concentration w at the first moment1The calculation formula of (2) is as follows:
the method for obtaining the methane desorption ratio provided by the embodiment of the invention is not influenced by the gas-containing structural characteristics of the sample, and the calculation of the methane desorption ratio can be carried out as long as the gas in the sample contains free gas and adsorption gas; the method for acquiring the methane absorption ratio provided by the embodiment of the invention has the characteristics of simplicity, economy and accuracy in directly testing the gas-containing structure.
Fig. 6 is a schematic block diagram of a system for acquiring a methane absorption ratio according to an embodiment of the present invention, and for convenience of explanation, only the portion related to the embodiment of the present invention is shown.
In the embodiment of the present invention, the system 60 for obtaining the methane absorption rate includes:
the experimental data acquisition module 61 is used for acquiring experimental data of a methane isothermal adsorption experiment;
a first methane concentration obtaining module 62, configured to obtain a free methane concentration at a first time, where the first time is any time in a methane adsorption process;
the first methane mass obtaining module 63 is configured to obtain a first adsorption state methane mass and a first total methane mass in the sample at the first moment according to the free state methane concentration and the experimental data at the first moment, where the first total methane mass is the total adsorption state and free state methane mass in the sample at the first moment;
and a first desorption ratio obtaining module 64, configured to obtain a methane desorption ratio at the first time according to the first adsorption methane mass and the first total methane mass.
Optionally, the experimental data comprises sample chamber volume, sample pore volume, and methane mass in the sample chamber at the first time;
the first methane quality acquisition module 63 includes:
the methane volume acquisition unit is used for acquiring the free methane volume according to the sample chamber volume, the sample volume and the sample pore volume;
the first calculation unit is used for obtaining the first adsorption methane quality according to the free methane concentration at the first moment, the free methane volume and the first methane quality;
and the second calculation unit is used for obtaining the first total methane mass according to the free methane concentration at the first moment, the methane mass at the first moment, the sample chamber volume and the sample volume.
Optionally, the experimental data includes a sample chamber volume, a sample mass, and a methane mass in the sample chamber at a second time, where the second time is a time of methane adsorption saturation;
the system 60 for obtaining the methane absorption ratio further includes:
the second methane concentration acquisition module is used for acquiring the free methane concentration at the second moment;
the adsorption quantity correction module is used for acquiring the excess adsorption quantity at the second moment and obtaining the absolute adsorption quantity at the second moment according to the excess adsorption quantity;
the second methane quality acquisition module is used for acquiring the second adsorption methane quality in the sample at the second moment according to the absolute adsorption quantity and the sample quality;
the third methane mass obtaining module is used for obtaining a second methane total mass according to the free methane concentration at the second moment, the methane mass at the second moment, the sample chamber volume and the sample volume, wherein the second methane total mass is the adsorption state in the sample at the second moment and the free methane total mass;
and the second absorption ratio acquisition module is used for acquiring the methane absorption ratio at the second moment according to the second adsorption methane mass and the second methane total mass.
Optionally, the experimental data includes experimental temperature, optical path length and experimental pressure at the first time;
the first methane concentration acquisition module 62 includes:
the integration unit is used for acquiring an absorbance curve of the methane at the first moment and integrating the absorbance curve of the methane at the first moment on a frequency domain to obtain a first integration area;
the absorption intensity acquisition unit is used for obtaining the absorption intensity of the gas molecular transition according to the experiment temperature;
and the methane concentration acquisition unit is used for acquiring the free methane concentration at the first moment according to the first integral area, the absorption intensity of the gas molecular transition, the optical path length and the experimental pressure at the first moment.
Optionally, in the first absorption ratio obtaining module 64, the formula for obtaining the methane absorption ratio at the first time according to the mass of the methane in the first adsorption state and the total mass of the methane is as follows:
wherein R isfree/adIs the methane free absorption ratio at the first moment, mad+freeIs the total mass of the first methane, madIs the first adsorption state methane mass.
It is clear to those skilled in the art that, for convenience and simplicity of description, the above division of the functional units and modules is only used for illustration, and in practical applications, the above function distribution may be performed by different functional units and modules as needed, that is, the internal structure of the system for acquiring the methane absorption rate is divided into different functional units or modules to perform all or part of the above described functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the above-mentioned apparatus may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
Fig. 7 is a schematic block diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 7, the terminal device 7 of this embodiment includes: one or more processors 70, a memory 71, and a computer program 72 stored in the memory 71 and executable on the processors 70. The processor 70, when executing the computer program 72, implements the steps in the above-described embodiments of the method for obtaining the methane absorption rate, such as the steps S201 to S204 shown in fig. 2. Alternatively, the processor 70, when executing the computer program 72, implements the functions of the modules/units in the above-described embodiment of the system for obtaining the absorption ratio, such as the functions of the modules 61 to 64 shown in fig. 6.
Illustratively, the computer program 72 may be partitioned into one or more modules/units that are stored in the memory 71 and executed by the processor 70 to accomplish the present application. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, which are used to describe the execution process of the computer program 72 in the terminal device 7. For example, the computer program 72 may be partitioned into an experimental data acquisition module, a first methane concentration acquisition module, a first methane mass acquisition module, and a first absorption ratio acquisition module.
The experimental data acquisition module is used for acquiring experimental data of the methane isothermal adsorption experiment;
the first methane concentration acquisition module is used for acquiring the free methane concentration at a first moment, wherein the first moment is any moment in the methane adsorption process;
the first methane quality acquisition module is used for respectively acquiring the first adsorption methane quality and the first total methane quality in the sample at the first moment according to the free methane concentration and the experimental data at the first moment, wherein the first total methane quality is the adsorption methane quality and the free methane quality in the sample at the first moment;
and the first absorption ratio acquisition module is used for acquiring the methane absorption ratio at the first moment according to the first adsorption state methane mass and the first methane total mass.
Other modules or units can refer to the description of the embodiment shown in fig. 6, and are not described again here.
The terminal device can be a desktop computer, a notebook, a palm computer, a cloud server and other computing devices. The terminal device 7 includes, but is not limited to, a processor 70 and a memory 71. It will be appreciated by those skilled in the art that fig. 7 is only one example of a terminal device and does not constitute a limitation of the terminal device 7, and may comprise more or less components than those shown, or some components may be combined, or different components, for example, the terminal device 7 may further comprise an input device, an output device, a network access device, a bus, etc.
The Processor 70 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory 71 may be an internal storage unit of the terminal device, such as a hard disk or a memory of the terminal device. The memory 71 may also be an external storage device of the terminal device, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like, which are provided on the terminal device. Further, the memory 71 may also include both an internal storage unit of the terminal device and an external storage device. The memory 71 is used for storing the computer program 72 and other programs and data required by the terminal device. The memory 71 may also be used to temporarily store data that has been output or is to be output.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
In the embodiments provided herein, it should be understood that the disclosed system and method for obtaining methane absorption rate can be implemented in other ways. For example, the embodiments of the system for obtaining methane absorption rate described above are merely illustrative, and for example, the division of the modules or units is only a logical division, and the actual implementation may have another division, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method of the embodiments described above can be realized by a computer program, which can be stored in a computer-readable storage medium and can realize the steps of the embodiments of the methods described above when the computer program is executed by a processor. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer readable medium may contain other components which may be suitably increased or decreased as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media which may not include electrical carrier signals and telecommunications signals in accordance with legislation and patent practice.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.
Claims (8)
1. A method for acquiring a methane free absorption ratio is characterized by comprising the following steps:
acquiring experimental data of a methane isothermal adsorption experiment;
obtaining the concentration of free methane at a first moment, wherein the first moment is any moment in the methane adsorption process;
respectively obtaining a first adsorption state methane mass and a first total methane mass in the sample at the first moment according to the concentration of the free state methane at the first moment and the experimental data, wherein the first total methane mass is the adsorption state and the free state methane mass in the sample at the first moment;
obtaining the methane absorption ratio at a first moment according to the mass of the first adsorption methane and the total mass of the first methane;
the experimental data comprise the volume of the sample chamber, the volume of the sample, the mass of the sample and the mass of methane in the sample chamber at a second moment, wherein the second moment is the moment of methane adsorption saturation;
the acquisition method further comprises the following steps:
obtaining the free methane concentration at the second moment;
acquiring the excess adsorption capacity at the second moment, and acquiring the absolute adsorption capacity at the second moment according to the excess adsorption capacity;
obtaining the mass of the second adsorption state methane in the sample at the second moment according to the absolute adsorption quantity and the sample mass;
obtaining a total mass of second methane according to the concentration of the free methane at the second moment, the mass of the methane at the second moment, the volume of the sample chamber and the volume of the sample, wherein the total mass of the second methane is the total mass of the adsorbed methane and the free methane in the sample at the second moment;
obtaining the methane absorption ratio at the second moment according to the second adsorption state methane mass and the second methane total mass;
wherein the calculation formula of the absolute adsorption amount at the second moment is as follows:
in the formula for calculating the absolute adsorption amount at the second time, nabsIs the absolute adsorption amount at the second time, nexcessIs the excess adsorption amount at the second time, ρgIs the free methane density at the second moment, padIs the adsorbed methane density at the second moment.
2. The method of obtaining a methane free absorption ratio of claim 1 wherein the experimental data further comprises a sample pore volume and a methane mass in the sample chamber at the first time;
respectively obtaining the first adsorption state methane mass and the first total methane mass in the sample at the first moment according to the free state methane concentration at the first moment and the experimental data, wherein the method comprises the following steps:
obtaining a methane volume in a free state from the sample chamber volume, the sample volume, and the sample pore volume;
obtaining the first adsorption state methane quality according to the free state methane concentration at the first moment, the free state methane volume and the first moment methane quality;
and obtaining the first total methane mass according to the free methane concentration at the first moment, the methane mass at the first moment, the sample chamber volume and the sample volume.
3. The method for obtaining the methane free absorption ratio according to claim 1, wherein the experimental data further comprises an experimental temperature, a path length, and an experimental pressure at the first time;
the acquiring of the free methane concentration at the first moment comprises:
acquiring an absorbance curve of methane at a first moment, and integrating the absorbance curve of methane at the first moment on a frequency domain to obtain a first integral area;
obtaining the absorption intensity of gas molecular transition according to the experiment temperature;
and obtaining the free methane concentration at the first moment according to the first integral area, the absorption intensity of the gas molecular transition, the optical path length and the experimental pressure at the first moment.
4. The method for obtaining the methane absorption rate according to claim 1, wherein the formula for obtaining the methane absorption rate at the first moment according to the first adsorbed methane mass and the first total methane mass is as follows:
wherein R isfree/adIs the methane free absorption ratio at the first moment, mad+freeIs the total mass of the first methane, madIs the first adsorbed state methane mass.
5. A system for obtaining a methane free absorption ratio, comprising:
the experimental data acquisition module is used for acquiring experimental data of the methane isothermal adsorption experiment;
the first methane concentration acquisition module is used for acquiring the free methane concentration at a first moment, wherein the first moment is any moment in the methane adsorption process;
the first methane quality obtaining module is used for respectively obtaining a first adsorption methane quality and a first total methane quality in the sample at the first moment according to the concentration of the free methane at the first moment and the experimental data, wherein the first total methane quality is the adsorption methane quality and the free methane quality in the sample at the first moment;
the first absorption ratio acquisition module is used for acquiring the methane absorption ratio at a first moment according to the first adsorption methane mass and the first total methane mass;
the experimental data comprise the volume of the sample chamber, the volume of the sample, the mass of the sample and the mass of methane in the sample chamber at a second moment, wherein the second moment is the moment of methane adsorption saturation;
the acquisition system further includes:
the second methane concentration acquisition module is used for acquiring the free methane concentration at the second moment;
the adsorption quantity correction module is used for acquiring the excess adsorption quantity at the second moment and obtaining the absolute adsorption quantity at the second moment according to the excess adsorption quantity;
the second methane quality obtaining module is used for obtaining the second adsorption methane quality in the sample at the second moment according to the absolute adsorption quantity and the sample quality;
a third methane mass obtaining module, configured to obtain a total second methane mass according to the free methane concentration at the second time, the methane mass at the second time, the sample chamber volume, and the sample volume, where the total second methane mass is a total methane mass in an adsorbed state and a free state in the sample at the second time;
the second absorption ratio acquisition module is used for acquiring the methane absorption ratio at a second moment according to the second adsorption methane mass and the second methane total mass;
wherein the calculation formula of the absolute adsorption amount at the second moment is as follows:
in the formula for calculating the absolute adsorption amount at the second time, nabsIs the absolute adsorption amount at the second time, nexcessIs the excess adsorption amount at the second time, ρgIs free methane density at the second moment，ρadIs the adsorbed methane density at the second moment.
6. The system for obtaining a methane gas absorption ratio of claim 5 wherein the experimental data further comprises a sample pore volume and a methane mass in the sample chamber at the first time;
the first methane quality acquisition module comprises:
a methane volume obtaining unit for obtaining a methane volume in a free state according to the sample chamber volume, the sample volume and the sample pore volume;
a first calculation unit, configured to obtain the first adsorbed methane quality according to the free methane concentration at the first time, the free methane volume, and the first methane quality;
and the second calculation unit is used for obtaining the first total methane mass according to the free methane concentration at the first moment, the methane mass at the first moment, the sample chamber volume and the sample volume.
7. A terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for obtaining a methane absorption rate according to any one of claims 1 to 4 when executing the computer program.
8. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program which, when executed by one or more processors, carries out the steps of the method for obtaining a methane absorption ratio according to any one of claims 1 to 4.
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