CN103994943B - A kind of coal/shale adsorption isotherm experiment device - Google Patents

Abstract

The invention provides a kind of coal/shale adsorption isotherm experiment device, device includes: the delivery outlet of reference still is connected by the first valve with the first port of mesozone, second port of mesozone is connected by the second valve with air accumulator, 3rd port of mesozone arranges the 3rd valve, and the 4th port of mesozone is connected by the 4th valve with sample still；May be contained within constant temperature control box with reference to still, sample still, temperature sensor, air accumulator and mesozone；The equipped at outlet port of sample still arranges filter screen；First pressure transducer force value in obtaining with reference to still；Second pressure transducer is for obtaining the force value in sample still；Temperature sensor temperature value during accurately measuring adsorption experiment；The gas required during the adsorption experiment of air accumulator carried out the pre-heat treatment before entering with reference to still and sample still；Mesozone is used for the progressively blood pressure lowering with reference to still and the progressively supercharging of sample still, it is thus achieved that repeatedly different after the adsorption equilibrium adsorbances under sample still pressure.

Description

A kind of coal/shale adsorption isotherm experiment device

Technical field

The present invention relates to adsorbance fields of measurement, particularly to a kind of coal/shale adsorption isotherm experiment device.

Background technology

At present, the experimental technique measuring Adsorption Isotherms mainly has volumetric method and the big class of gravimetric method two.Wherein, hold Area method is divided into constant volume type and constant-pressure type according to gas injection mode difference.

Constant volume type volumetric method, as the most commonly used method, its experimental provision mainly by gas cylinder, vacuum pump, booster pump, Formed with reference to still, sample still, pressure and temperature sensor and calorstat, in experimentation, first in reference to still Injecting Adsorbate Gas, after pressure stability, record is with reference to still pressure, then opens with reference to the centre between still and sample still Valve, allows gas isothermal expansion enter sample still, waits record balance pressure after adsorption equilibrium, according to the principle of mass conservation Just can calculate each absorption increment, accumulation summation obtains the adsorbance under corresponding pressure.Repeat aforementioned process, just Whole piece adsorption isotherm can be obtained.

Constant-pressure type volumetric method is similar to therewith, except for the difference that by reference still fixing for volume with the piston pump generation of a variable volume Replacing, Adsorbate Gas is that constant voltage is injected in sample still, same, utilizes the conservation of mass to calculate adsorbance.But by The shortcomings such as, sealing property bad, be suitable for condition of high voltage poor, operation inconvenience more complicated in variable volume piston pump, the most very Few use, people's commonly used constant volume type volumetric method, i.e. tradition volumetric method.

Gravimetric method is to calculate adsorbance according to the weight change of sample before and after absorption, and its main device is by electromagnetic suspension system sky Flat, high-pressure sealed still and calorstat composition.Wherein, airtight still is separated into two confined chambers, rock sample to be measured and height Body of calming the anger is respectively placed in two confined chambers, in experimentation, first records the quality readings of sample still, the most progressively In sample still, be filled with gas to be measured, wait balance reading stable after sample quality when recording adsorption equilibrium, front and back two The difference of inferior quality is the quality of adsorbed gas.There is buoyant weight due to gas in gravimetric method experimentation, therefore test it Before need to carry out buoyancy correction of weighing.

Experimental facilities cost needed for gravimetric method is relatively costly, is rarely employed at present.

At present, the experimental provision of Automated condtrol is few, is to need people to carry out Non-follow control mostly, on the one hand, manually Controlling to need to open calorstat, the temperature fluctuation causing experimental situation is relatively big, extends pressure balance time, i.e. needs Treat the longer adsorption experiment time；On the other hand, Non-follow control needs manpower, and Stress control is not accurate enough.And If the problem in terms of employing automation control system, the two all can be well solved.

At present, people are all based on the different adsorption experimental apparatus of tradition volumetric method principle design, not to volume The experiment flow of method has too many research, and the error in experimentation and error influence factor the most do not carry out detailed dividing Analysis.The high pressure isothermal adsorption test method (with reference to standard GB/T/T19560-2008) of coal is also based on tradition appearance The experimental principle of area method, experiment flow is not changed in.Chinese invention patent CN102607991A is coal/shale absorption Amount determining device, simulates the absorbed natural gas process of actual geology Coal Under/shale though this device possesses and inhales it Attached ability is evaluated, but measuring method is still that tradition volumetric method.

Experimental provision required for tradition volumetric method is simple and convenient to operate, but the experimental implementation of multiple injection gas can bring survey The repeatedly accumulation of amount error, the experimental error causing measurement result is very big, and adsorption isotherm may finally be caused abnormal, Therefore this method is only applicable to the adsorbent (such as activated carbon etc.) of adsorbance big (measurement error impact is little), for absorption The measurement of coal/shale that tolerance is the lowest produces the biggest error, has a strong impact on experimental result.Patent CN102607991A Although possessing the ability that coal/shale adsorbance measures, and propose to utilize pneumatic operated valve to carry out procedure auto-control, simulation storage Stressor layer is higher, but its principle is constant volume type volumetric method, and the error of measurement result is the biggest, does not ensures that accurately Measure the absorbability of gas with various in the actual formation Coal Under/shale such as High Temperature High Pressure.

Summary of the invention

In order to eliminate the error accumulation during tradition volumetric method is measured, reduce the experimental error of measurement result, this Invention provides a kind of coal/shale adsorption isotherm experiment device, by improving experimental provision so that accurately measure high temperature The absorbability of gas with various in the actual formation Coal Under/shale such as high pressure.

For achieving the above object, the invention provides a kind of coal/shale adsorption isotherm experiment device, described experimental provision Including: with reference to still, sample still, the first pressure transducer, the second pressure transducer, temperature sensor, thermostatic control Case, air accumulator and filter screen；Described experimental provision also includes: mesozone；Wherein,

The described delivery outlet with reference to still is connected by the first valve with the first port of described mesozone, described mesozone Second port is connected by the second valve with described air accumulator, and the 3rd port of described mesozone arranges the 3rd valve, 4th port of described mesozone is connected by the 4th valve with described sample still；

Described reference still, described sample still, described temperature sensor, described air accumulator and described mesozone may be contained within In described constant temperature control box；

The equipped at outlet port of described sample still arranges described filter screen；

Described first pressure transducer, the force value in obtaining described reference still；

Described second pressure transducer, for obtaining the force value in described sample still；

Described temperature sensor, the temperature value during accurately measuring adsorption experiment；

Described air accumulator, was carried out before entering with reference to still and sample still for gas required during adsorption experiment The pre-heat treatment；

Described mesozone, for the described progressively blood pressure lowering with reference to still and the progressively supercharging of described sample still, it is achieved acquisition is many The adsorbances under sample still pressure different after secondary adsorption equilibrium.

Optionally, in an embodiment of the present invention, described experimental provision also includes: gas chromatograph；

Described gas chromatograph, for when carrying out multicomponent gas experiment, entering by the 3rd valve of described mesozone Row takes gas, then carries out gas composition analysis.

Optionally, in an embodiment of the present invention, the volume of described mesozone is the described volume with reference to still $\frac{1}{20}~\frac{1}{15}.$

Optionally, in an embodiment of the present invention, described first valve, described second valve, described 3rd valve and Described 4th valve is pneumatic operated valve.

Optionally, in an embodiment of the present invention, described experimental provision also includes flow-limiting valve；

In described pipeline between delivery outlet and described first valve with reference to still, described flow-limiting valve is set, for accurately control Make described with reference to still progressively blood pressure lowering.

Compared with traditional device, the effect of this device and advantage are embodied in the following aspects:

1, this device is being provided with mesozone with reference between still and sample still, is connected by valve, and based on volume The ultimate principle of method, it is proposed that the measuring method that adsorption isotherm experiment is new, is effectively reduced gas injection number of times, shortens absorption Experimental period.

2, owing to being provided with mesozone, can realize, with reference to the progressively blood pressure lowering of still, the progressively supercharging of sample still, solving The difficult problem from high pressure the most progressively blood pressure lowering faced in prior art, and provide a resolving ideas clearly.

3, the experimental provision after improving can effectively reduce the experimental error of measurement result, improves certainty of measurement.

4, when carrying out multicomponent gas experiment, gas can be taken by mesozone, carry out gas by gas chromatograph Component analysis, reduces the risk taking gas under conventional art.

Accompanying drawing explanation

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing In having technology to describe, the required accompanying drawing used is briefly described, it should be apparent that, the accompanying drawing in describing below is only It is some embodiments of the present invention, for those of ordinary skill in the art, in the premise not paying creative work Under, it is also possible to other accompanying drawing is obtained according to these accompanying drawings.

Fig. 1 is a kind of coal/shale adsorption isotherm experiment device schematic diagram that the present invention proposes；

Fig. 2 is the measurement result error contrast schematic diagram with tradition volumetric method measurement result of the present embodiment.

Accompanying drawing identifies:

1, gas bomb, 2, helium steel cylinder, 3, gas boosting pump, 4, vacuum meter, 5, six-way valve, 6, vacuum pump, 7, first manual valve, the 8, second hand-operated valve, the 9, the 3rd hand-operated valve, the 10, the 4th hand-operated valve, the 11, the 5th is manual Valve, the 12, the 6th hand-operated valve, 13, temperature sensor, 14, air accumulator, 15, with reference to still, the 16, first pressure passes Sensor, 17, flow-limiting valve, the 18, first pneumatic operated valve, the 19, second pneumatic operated valve, the 20, the 3rd pneumatic operated valve, the 21, the 4th Pneumatic operated valve, 22, gas chromatograph, the 23, second pressure transducer, 24, filter screen, 25, sample still, 26, constant temperature Control chamber, 27, mesozone.

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Describe wholely.Obviously, described embodiment is only a part of embodiment of the present invention rather than whole embodiments. Based on the embodiment in the present invention, those of ordinary skill in the art are obtained under not making creative work premise Every other embodiment, broadly falls into the scope of protection of the invention.

Record according to background section and understand, owing to the gas flow required for completing whole adsorption experiment is more, therefore After the disposable Adsorbate Gas injecting q.s, the highest with reference to the initial pressure of still, and the initial pressure of sample still is near Seemingly for vacuum, need progressively blood pressure lowering with reference to still during adsorption experiment, be difficult in the state of the art pass through valve Accurately control, in order to realize the progressively pressure reduction with reference to still, during the technical program is provided with on experimental provision Between district, utilize the method that mesozone carries out progressively blood pressure lowering.Simultaneously in order to preferably control pressure, after with reference to still Pipeline be provided with a flow-limiting valve 17.

Concrete technical thought is: in the middle of with reference to still and experiment still, arrange the centre of a volume the least (1-2ml) District, owing to mesozone volume relatively amasss much smaller with reference to kettle, therefore, even if under high-pressure situations, sample still is each Pressure increase is also certain, can be by gas progressively supercharging in sample still of Valve controlling mesozone.So, In the technical program, mesozone has an effect in terms of following two:

1, mesozone smaller size smaller is utilized to realize with reference to the progressively blood pressure lowering of still, the progressively pressurization of sample still, should Method is simple and convenient, pressure controllable is strong；Further, during adsorption experiment, when carrying out single-component gas experiment, Owing to disposably being injected the Adsorbate Gas of q.s to reference still by mesozone, and by mesozone to reference to still Carry out gradually reducing pressure, sample still is stepped up pressure, obtain after multiple different adsorption equilibrium in sample still Adsorbance corresponding under pressure.If conventional art to obtain after 5 different adsorption equilibriums corresponding under pressure in sample still Adsorbance, it is necessary to successively 5 times to reference to injecting Adsorbate Gas in still so that the experimental error of measurement result obtains To accumulation, so technical scheme can reduce the experimental error of measurement result.

2, during adsorption experiment, when carrying out multicomponent gas experiment, after adsorption equilibrium, mesozone is utilized Take gas, and carry out gas composition analysis by gas chromatograph.

As it is shown in figure 1, a kind of coal/shale adsorption isotherm experiment device schematic diagram proposed for the present invention.Described experiment dress Put and include: with reference to still 15, sample still the 25, first pressure transducer the 16, second pressure transducer 23, temperature sensor 13, constant temperature control box 26, air accumulator 14 and filter screen 24；Wherein, described experimental provision also includes: mesozone 27；

The described delivery outlet with reference to still 15 is connected by the first valve 18 with the first port of described mesozone 27, described in Between second port in district 27 be connected by the second valve 19 with described air accumulator 14, the 3rd port of described mesozone 27 Arranging the 3rd valve 20, the 4th port of described mesozone 27 is connected by the 4th valve 21 with described sample still 25；

Described with reference to still 15, described sample still 25, described temperature sensor 13, described air accumulator 14 and described mesozone 27 may be contained within described constant temperature control box 26；

The equipped at outlet port of described sample still 25 arranges described filter screen 24；

Described first pressure transducer 16, the force value in obtaining described reference still 15；

Described second pressure transducer 23, for obtaining the force value in described sample still 25；

Described temperature sensor 13, the temperature value during accurately measuring adsorption experiment；

Described air accumulator 14, is entering described reference still 15 and described sample for gas required during adsorption experiment The pre-heat treatment is carried out before product still 25；

Described mesozone 27, for the described progressively blood pressure lowering with reference to still 15 and the progressively pressurization of described sample still 25.

Optionally, in an embodiment of the present invention, described experimental provision also includes: gas chromatograph 22；

Described gas chromatograph 22, for when carrying out multicomponent gas experiment, by the 3rd valve of described mesozone 27 Door 20 carries out taking gas, then carries out gas composition analysis.

Optionally, in an embodiment of the present invention, the volume of described mesozone 27 is the described volume with reference to still 15 $\frac{1}{20}~\frac{1}{15}.$

Optionally, in an embodiment of the present invention, described first valve 18, described second valve 19, described 3rd valve Door 20 and described 4th valve 21 are pneumatic operated valve.

Optionally, in an embodiment of the present invention, described experimental provision also includes flow-limiting valve 17；

In described pipeline between delivery outlet and described first valve 18 with reference to still 15, described flow-limiting valve 17 is set, is used for Control the described progressively blood pressure lowering with reference to still 15.

Below as a example by methane (purity > 99.99%) gas adsorption experiment on shale, the technical program is made in detail Thin introduction.But these examples can not be understood to that the present invention can the restriction of practical range.

In an embodiment of the present invention, experimental provision as shown in Figure 1 is used.The volume of mesozone is 2ml, reference The volume of still is 30ml, and the volume of sample still is 60ml.The volume sum with reference to still with mesozone can also be just known that, When carrying out multicomponent gas experiment, this device is used to obtain with reference to the volume of still by standardizition, it becomes possible to obtain Obtain the volume of mesozone.

During adsorption experiment, testing sample can be rock core, it is also possible to be the particle powder (granularity one after grinding As be 80 mesh～100 mesh), in order to avoid rock particles enters pressure line from sample still 25, in the upper end of sample still 25 Lid is provided with the filter screen 24 of 2 μm.In order to carry out multicomponent gas adsorption experiment, gas chromatograph 22 is permissible The 3rd port utilizing mesozone 27 carries out taking gas operation, then carries out gas composition analysis.

The detailed process of experiment is as follows: first according to actual formation condition testing sample is carried out water balance process or puts Dry in the drying baker of 110 DEG C and reach 12 hours, then utilize trace electronic balance weighing equilibrium water or dried Testing sample quality, is positioned over testing sample in sample still 25 rapidly, and the temperature arranging constant temperature control box 26 is required Experimental temperature, demarcates followed by the free space volumes in sample still 25, specifically comprises the following steps that

1, close the 3rd pneumatic operated valve 20, close the 4th hand-operated valve 10 and the 6th hand-operated valve 12, open vacuum pump the 6, the 5th Hand-operated valve 11 and vacuum meter 4, to the experimental provision system evacuation in constant temperature control box 26, about 1 hour persistent period, Close the 5th hand-operated valve 11 and vacuum pump 6, utilize temperature sensor 13 and vacuum meter 4 to obtain the initial temperature of sample still 25 And initial pressure；

2, close the second pneumatic operated valve 19, open the second hand-operated valve the 8, the 3rd hand-operated valve 9 and the 4th hand-operated valve 10, by helium Gas in gas cylinder 2 injects air accumulator 14 and preheats, and closes the 4th pneumatic operated valve 21, opens the first pneumatic operated valve 18 He Second pneumatic operated valve 19, injects quantitative helium in reference to still 15, cuts out the second pneumatic operated valve 19, wait after pressure stabilisation, Obtain the initial pressure with reference to still 15 by the first pressure transducer 16, obtained with reference to still 15 by temperature sensor 13 Initial temperature；

3, open the 4th pneumatic operated valve 21, under the effect of the pressure, after allowing helium isothermal enter sample still 25, close the Four pneumatic operated valves 21, after waiting the pressure balance in two stills and stablizing, utilize the first pressure transducer 16 to obtain demarcation flat With reference to still pressure after weighing apparatus, utilize the second pressure transducer 23 to obtain and demarcate sample still pressure after balance, meanwhile, utilize temperature Degree sensor 13 obtains reference still and the temperature of sample still after demarcation balance respectively；

4, in the case of known reference still 15 with the volume sum of mesozone 27, known sample still 25 volume, according to The principle of mass conservation, is calculated the free space volumes in sample still 25.Computing formula is as follows:

$V_{\mathrm{void}}=\frac{(\frac{P_1}{Z_1}-\frac{P_2}{Z_2})}{(\frac{P_3}{Z_3}-\frac{P_0}{Z_0})}{V}_{\mathrm{ref}}$

In formula, P₀For the initial pressure of sample still, P₁For the initial pressure with reference to still, unit is MPa；P₂For mark Allocate the pressure with reference to still, P after weighing apparatus₃For the pressure of sample still after demarcation balance, unit is MPa；Z₀For sample still Initial pressure under the compressibility factor of helium, Z₁For the compressibility factor of helium, Z under the initial pressure with reference to still₂For demarcating The compressibility factor of helium, Z under the pressure of sample still after balance₃Pressure for the helium under the pressure of reference still after demarcation balance The contracting factor；V_refBeing the volume sum with reference to still with mesozone, unit is ml；V_voidIt it is free space body in sample still Long-pending, unit is ml.

It follows that carry out adsorption isotherm experiment, detailed operating procedure is as follows:

1, close the 3rd pneumatic operated valve the 20, the 4th hand-operated valve 10 and the 6th hand-operated valve 12, open vacuum pump the 6, the 5th Hand-operated valve 11 and vacuum meter 4, to the experimental provision system evacuation in constant temperature control box 26,1 hour persistent period Left and right, closes the 5th hand-operated valve 11 and vacuum pump 6, utilizes vacuum meter 4 to obtain the initial pressure P of sample still 25₀ ^sam；

2, close the second pneumatic operated valve 19, open first manual valve the 7, the 3rd hand-operated valve 9 and the 4th hand-operated valve 10, profit With booster pump 3 methane gas in gas bomb 1 is pressurized to test desirable pressure, and injects air accumulator 14 and carry out The pre-heat treatment, closes the 4th pneumatic operated valve 21, opens the first pneumatic operated valve 18 and the second pneumatic operated valve 19, to reference to still 15 In the disposable methane gas injecting q.s, close the second pneumatic operated valve 19, wait after pressure stabilisation, by first Pressure transducer 16 obtains the initial pressure P with reference to still 15₀ ^ref, obtained with reference to still 15 by temperature sensor 13 Initial temperature；

3, close the first pneumatic operated valve 18, open the 4th pneumatic operated valve 21, under the effect of the pressure, in mesozone 27 Gas isothermal expansion enters in sample still 25, after the pressure balance in the pressure in mesozone 27 and sample still 25, Close the 4th pneumatic operated valve 21, open the first pneumatic operated valve 18, treat the pressure in mesozone 27 and with reference to the pressure in still 15 Dynamic balance and stable after, obtain the pressure P with reference to still 15 by the first pressure transducer 16₁ ^ref, by the second pressure Sensor 23 obtains the pressure P of sample still 25₁ ^sam；

4, i repeat the above steps 3, record is P with reference to the pressure in still 15 and sample still 25 respectively_i ^ref、P_i ^sam, Unit testing sample matter corresponding under the pressure of sample still after i & lt adsorption equilibrium just can be calculated according to the conservation of mass The adsorbance (m mol) of amount, computing formula is as follows:

$n_a\left(i\right)=(\frac{P_0^{\mathrm{ref}}}{Z_0^{\mathrm{ref}}}-\frac{P_i^{\mathrm{ref}}}{Z_i^{\mathrm{ref}}})\frac{V_{\mathrm{ref}}}{\mathrm{RT}}-(\frac{P_i^{\mathrm{sam}}}{Z_i^{\mathrm{sam}}}-\frac{P_0^{\mathrm{sam}}}{Z_0^{\mathrm{sam}}})\frac{V_{\mathrm{void}}}{\mathrm{RT}}$

In formula, R is ideal gas constant, for 8.31451J/mol/k；T is experimental temperature, and unit is K；V_refIt is With reference to the volume sum of still with mesozone, ml；V_voidBeing free space volumes in sample still, unit is ml；It is With reference to still initial pressure P₀ ^refUnder the compressibility factor of methane；It is with reference to still pressure P_i ^refUnder methane compression because of Son；It is sample still pressure P_i ^samUnder methane compressibility factor；It is the initial pressure P of sample still₀ ^samUnder The compressibility factor of methane.

5, unit testing sample corresponding under the pressure of sample still after adsorption equilibrium is obtained according to testing sample Mass Calculation The adsorbance (mmol/g) of quality, can draw the adsorption isotherm of shale.

As in figure 2 it is shown, be the measurement result error contrast schematic diagram with tradition volumetric method measurement result of the present embodiment. If carrying out adsorption experiment by tradition volumetric method, when calculating adsorbance, it is first to calculate single adsorptions increment, then Adsorbance corresponding under pressure in sample still after adsorption equilibrium is obtained by cumulative summation.Divided by the derivation of equation and error Analysis, show that the uncertainty of the measurement result of tradition volumetric method is:

${\mathrm{\σ}}_{n_a\left(i\right)}=\sqrt{\underset{k=1}{\overset{i}{\mathrm{\Σ}}}{\mathrm{\σ}}_{\mathrm{\Δ}{n}_a\left(k\right)}^2}=\sqrt{{\mathrm{\σ}}_{{\mathrm{\Δn}}_a\left(1\right)}^2+{\mathrm{\σ}}_{{\mathrm{\Δn}}_a\left(2\right)}^2+...+{\mathrm{\σ}}_{{\mathrm{\Δn}}_a\left(i\right)}^2}$

Wherein:

${\mathrm{\σ}}_{{\mathrm{\Δn}}_a\left(i\right)}^2={({\mathrm{\ρ}}_{2i-1}-{\mathrm{\ρ}}_{2i})}^2{\mathrm{\σ}}_{V_{\mathrm{ref}}}^2+({\mathrm{\σ}}_{{\mathrm{\ρ}}_{2i-1}}^2+{\mathrm{\σ}}_{{\mathrm{\ρ}}_{2i}}^2)V_{\mathrm{ref}}^2+{({\mathrm{\ρ}}_{2i}-{\mathrm{\ρ}}_{2i-2})}^2{\mathrm{\σ}}_{V_{\mathrm{void}}}^2+({\mathrm{\σ}}_{{\mathrm{\ρ}}_{2i}}^2+{\mathrm{\σ}}_{{\mathrm{\ρ}}_{2i-2}}^2)V_{\mathrm{viod}}^2$

In formula, Δ n_aI () is single adsorptions increment during i & lt absorption, unit is mol；ρ_2i-2It it is i & lt adsorption equilibrium Gas density in front sample still, unit is mol/ml；ρ_2i-1It is close with reference to the gas in still before i & lt adsorption equilibrium Degree, unit is mol/ml；ρ_2iBeing the gas density after i & lt adsorption equilibrium in sample still, unit is mol/ml；σ_ρ2i-2 It it is gas density ρ_2i-2Standard deviation, unit is mol/ml；σ_ρ2i-1It it is gas density ρ_2i-1Standard deviation, single Position is mol/ml；σ_ρ2iIt it is gas density ρ_2iStandard deviation, unit is mol/ml；It is V_refStandard deviation, Unit is ml；It is V_voidStandard deviation, unit is ml.V_refIt is the volume sum with reference to still with mesozone, Unit is ml；V_voidBeing free space volumes in sample still, unit is ml.

And for the technical scheme of the present embodiment, calculate adsorbance time, be directly be calculated adsorption equilibrium after Adsorbance corresponding under pressure in sample still, by the derivation of equation and error analysis, draws the measurement knot of the technical program The uncertainty of fruit is:

${\mathrm{\σ}}_{n_a\left(i\right)}=\sqrt{{({\mathrm{\ρ}}_0^{\mathrm{ref}}-{\mathrm{\ρ}}_i^{\mathrm{ref}})}^2{\mathrm{\σ}}_{V_{\mathrm{ref}}}^2+({\mathrm{\σ}}_{{\mathrm{\ρ}}_0^{\mathrm{ref}}}^2+{\mathrm{\σ}}_{{\mathrm{\ρ}}_i^{\mathrm{ref}}}^2){V_{\mathrm{ref}}}^2+{({\mathrm{\ρ}}_i^{\mathrm{sam}}-{\mathrm{\ρ}}_0^{\mathrm{sam}})}^2{\mathrm{\σ}}_{V_{\mathrm{void}}}^2+({\mathrm{\σ}}_{{\mathrm{\ρ}}_i^{\mathrm{sam}}}^2+{\mathrm{\σ}}_{{\mathrm{\ρ}}_0^{\mathrm{sam}}}^2){V_{\mathrm{void}}}^2}$

In formula,It is with reference to still initial pressure P₀ ^refUnder gas density, unit is mol/ml；It is with reference to still Pressure P_i ^refUnder gas density, unit is mol/ml；It is sample still initial pressure P₀ ^samUnder gas density, Unit is mol/ml；It is sample still pressure P_i ^samUnder gas density, unit is mol/ml；It is gas DensityStandard deviation, unit is mol/ml；It it is gas densityStandard deviation, unit is mol/ml；It it is gas densityStandard deviation, unit is mol/ml；It it is gas density's Standard deviation, unit is mol/ml.

In fig. 2, the numerical value on abscissa is the force value after adsorption equilibrium in sample still, and unit is MPa, vertical Numerical value on coordinate is the adsorbance of unit testing sample quality corresponding under the pressure of sample still after adsorption equilibrium, unit Being mmol/g, the line of I shape is experimental error line.Wherein, in Fig. 2, the minima of experimental error line is that absorption is flat After weighing apparatus, in sample still, under pressure, experiment is measured the absorption value obtained and is deducted what the uncertainty of measurement result obtained, with Reason, after in Fig. 2, the maximum of experimental error line is adsorption equilibrium, in sample still, under pressure, the adsorbance obtained is measured in experiment Value adds what the uncertainty of measurement result obtained.By comparing it is found that after identical adsorption equilibrium sample still Under interior force value, the experimental error line at round dot place is shorter than the experimental error line at triangle place, can draw: this The experimental error of bright measurement result is far smaller than the experimental error that tradition volumetric method is measured.

Further, the uncertainty formula comparing above-mentioned two measurement result finds: this invention removes error accumulation, Under conditions of the equipment of same precision, enable to measurement result more accurate, greatly reduce the experiment of measurement result Error.

Further, when the device using Fig. 1 implements the experiment flow of the present embodiment, mesozone can realize with reference to still by Step blood pressure lowering, the progressively supercharging of sample still, solve the difficult problem from high pressure the most progressively blood pressure lowering faced in prior art, And provide a resolving ideas clearly.Further, it is effectively reduced gas injection number of times, shortens the adsorption experiment time.

Separately, when carrying out multicomponent gas experiment, gas can be taken by mesozone, carry out gas by gas chromatograph Component analysis, reduces the risk taking gas under conventional art.

Last it is noted that above-mentioned only in order to the present invention is described and and unrestricted technical scheme described in the invention； Although this specification is to present invention has been detailed description, but, those skilled in the art still can be right The present invention modifies or equivalent, and all are without departing from the technical scheme of the spirit and scope of the present invention and improvement thereof, It all should be contained in scope of the presently claimed invention.

Claims (5)

1. coal/shale adsorption isotherm experiment device, described experimental provision includes: with reference to still, sample still, first Pressure transducer, the second pressure transducer, temperature sensor, constant temperature control box, air accumulator and filter screen；Its feature exists In, described experimental provision also includes: mesozone；Wherein,

The described delivery outlet with reference to still is connected by the first valve with the first port of described mesozone, described mesozone Second port is connected by the second valve with described air accumulator, and the 3rd port of described mesozone arranges the 3rd valve, 4th port of described mesozone is connected by the 4th valve with described sample still；

Described reference still, described sample still, described temperature sensor, described air accumulator and described mesozone may be contained within In described constant temperature control box；

The equipped at outlet port of described sample still arranges described filter screen；

Described first pressure transducer, the force value in obtaining described reference still；

Described second pressure transducer, for obtaining the force value in described sample still；

Described temperature sensor, the temperature value during accurately measuring adsorption experiment；

Described air accumulator, was carried out before entering with reference to still and sample still for gas required during adsorption experiment The pre-heat treatment；

Described mesozone, for during adsorption experiment, when carrying out single-component gas experiment, to described with reference to still one Secondary property injects the Adsorbate Gas of q.s；And described mesozone is for gradually reducing pressure to described with reference to still Power, is stepped up pressure to described sample still, it is thus achieved that correspondence under sample still pressure after multiple different adsorption equilibriums Adsorbance.

2. device as claimed in claim 1, it is characterised in that described experimental provision also includes: gas chromatograph；

Described gas chromatograph is for when carrying out multicomponent gas experiment, carrying out by the 3rd valve of described mesozone Take gas, then carry out gas composition analysis.

3. device as claimed in claim 1 or 2, it is characterised in that the volume of described mesozone is described with reference to still Volume

4. device as claimed in claim 1 or 2, it is characterised in that described first valve, described second valve, Described 3rd valve and described 4th valve are pneumatic operated valve.

5. device as claimed in claim 1 or 2, it is characterised in that described experimental provision also includes flow-limiting valve；

In described pipeline between delivery outlet and described first valve with reference to still, described flow-limiting valve is set, for accurately control Make described with reference to still progressively blood pressure lowering.