CN103575622B - A kind of method of testing of wax molecular diffusivity - Google Patents
A kind of method of testing of wax molecular diffusivity Download PDFInfo
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- CN103575622B CN103575622B CN201310507197.3A CN201310507197A CN103575622B CN 103575622 B CN103575622 B CN 103575622B CN 201310507197 A CN201310507197 A CN 201310507197A CN 103575622 B CN103575622 B CN 103575622B
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Abstract
The invention provides a kind of method of testing and device thereof of wax molecular diffusivity, described method of testing comprises the following steps: 1) pump in kapillary by carrying object solution, again pulse solution is injected this kapillary, spread in the Laminar Flow that pulse solution is formed at carrying object solution, and control described carrying object solution and described pulse solution is diffused into tube wall time from kapillary center and be less than the time being diffused into outlet from capillary inlet; 2) that detects solution in kapillary by UV detecting device washes out peak, obtains wax molecular diffusivity: <maths num=" 0001 " > by following formula
d in </maths> formula
aBfor wax molecular diffusivity, m
2/ s; W
1/2for half-peak breadth, s; R is kapillary inside radius, m; t
rfor appearance time, s.Present invention also offers the device that can realize this method of testing.Method of testing provided by the invention can be convenient, fast and determine wax molecular diffusivity exactly.
Description
Technical field
The present invention relates to a kind of method of testing and device thereof of wax molecular diffusivity.
Background technology
Crude oil is a kind of hydro carbons and non-hydrocarbons potpourri, wherein C of complexity
17above n-alkane is called wax.The reduction of the solubility with temperature of wax in crude oil and declining, when crude oil temperature is reduced to wax precipitation piont temperature, wax is crystallization because of supersaturation.The crude oil solidifying point of high-content wax is higher, often need to adopt heated transportation crude oil to ensure the mobility of crude oil, the phenomenon of such appearance is: in pipe, oil temperature is usually all higher than pipe surface temperature, when pipe surface temperature is lower than crude oil wax precipitation piont, the wax molecule of near-wall takes the lead in separating out and part is deposited on tube wall, thus the wax molecular conecentration forming tube hub and tube wall place is poor.Under the driving of wax molecular conecentration difference, wax molecule spreads to tube wall, finally separates out at tube wall and forms wax deposit layer.Along with the increase of wax deposit layer thickness, the circulation area of pipeline reduces, and crude oil flow resistance increases, and pipeline transmission capacity reduces, even blocking pipe, thus causes industrial accident.
For improving pipeline transmission capacity and the efficiency of crude oil, problem for the wax deposit produced due to wax molecular diffusion in above-mentioned crude oil proposes effective solution, and carrying out prediction by the wax deposit layer thickness profile of Wax Deposition Model to wax-containing oil pipe is an element task.In order to describe the diffusion process of wax molecule, obtaining the coefficient of diffusion of wax molecule in crude oil is a key factor.But, on the one hand, because the basic database of molecular diffusivity is not set up, the True Data of the wax molecular diffusivity provided in handbook and document is very rare, therefore Wax Deposition Model nearly all at present all adopts experimental formula to calculate the coefficient of diffusion of wax molecule in crude oil; On the other hand, be commonly used to measure the experimental technique such as membrane cisterna method, interferometric method of molecular diffusivity and there is the defects such as consuming time, apparatus expensive, complex operation.Therefore, how can effective method be used, convenient, fast and the coefficient of diffusion determining wax molecule is exactly people's problem demanding prompt solution always.
Summary of the invention
Technical problem underlying solved by the invention, is the method for testing providing a kind of wax molecular diffusivity, and the method can be convenient, fast and determine wax molecular diffusivity exactly.
Present invention also offers a kind of device that can realize above-mentioned method of testing.
The invention provides a kind of method of testing of wax molecular diffusivity, described method of testing comprises the following steps:
1) carrying object solution is pumped in kapillary, again pulse solution is injected this kapillary, spread in the Laminar Flow that pulse solution is formed at carrying object solution, and control described carrying object solution and described pulse solution is diffused into tube wall time from kapillary center and be less than the time being diffused into outlet from capillary inlet;
Wherein, described carrying object solution and described pulse solution are the solution with identical solute and solvent, but there is solubility difference between two kinds of solution, described solute is have the n-alkane being not less than C17 carbon chain lengths, described solvent is have the hydro carbons, alcohols or the aromatic substance that are not more than C10 carbon chain lengths, further, the flow velocity of described carrying object solution forms Laminar Flow, meets following formula:
2rUρ/η≤2000
In formula, U is the flow velocity of carrying object solution, ms
-1; R is kapillary inside radius, m; ρ is the density of carrying object solution, kgm
-3; η is the kinetic viscosity of carrying object solution, Pas;
2) that detects solution in kapillary by UV detecting device washes out peak, obtains wax molecular diffusivity by following formula:
D in formula
aBfor wax molecular diffusivity, m
2/ s; W
1/2for half-peak breadth, s; R is kapillary inside radius, m; t
rfor appearance time, s.
In specific embodiment of the invention scheme, this method of testing also comprises before testing to the initialization of proving installation, comprising: adopt described carrying object solution carry out rinse to described kapillary and arrange the determined wavelength of UV detecting device.
In the present invention, the determined wavelength that UV detecting device is set usually described carrying object solution maximum absorption wavelength ± 5nm within the scope of, the determined wavelength of this scope is conducive to obtaining test result more accurately.Such as, for most of alkane, alcohol, ketone organic substance, the determined wavelength within the scope of 190 ~ 200nm can be selected.
In specific embodiment of the invention scheme, control described carrying object solution and the described pulse solution initial concentration difference based on mole fraction within ± 0.1.Usually, when UV detecting device can detect solution in kapillary wash out peak, the initial concentration difference of pulse solution and carrying object solution, within ± 0.1, can ensure that the concentration of pulse solution does not have an impact to the concentration of carrying object solution like this.
In the actual test process of wax molecular diffusivity, the impact of the accuracy stand under load fluid solution flow velocity of wax molecular diffusivity, can control the flow velocity of carrying object solution usually by adjustment pump discharge.In the present invention, control carrying object solution pumps into the pump discharge of kapillary is 0.001 ~ 0.999mLmin
-1.
Present invention also offers a kind of device realizing above-mentioned method of testing, this device comprises: high pressure constant flow pump, kapillary, sampling valve, sump assemblies, water bath with thermostatic control, UV detecting device and data collection task station;
The transfusion outlet of described sump assemblies is connected with the import of described high pressure constant flow pump;
Be connected by described sampling valve between described high voltage and constant current delivery side of pump and the import of described kapillary; Wherein, described kapillary is placed in described water bath with thermostatic control;
The outlet of described kapillary is connected with described UV detecting device;
Described UV detecting device connects described data collection task station.
In proving installation of the present invention, described kapillary can be polyetheretherketone kapillary; The signal accuracy of described UV detecting device is 10
-6au, baseline noise is no more than 5 × 10 for the methyl alcohol of 20 DEG C
-5au; Described reservoir is for storing carrying object solution; Described sampling valve can be manual micro-sampling valve, controls by quantitative loop the volume injecting kapillary pulse solution.
The present invention has following beneficial effect:
1, compared to prior art empirically formula to calculating wax molecular diffusivity, method of testing of the present invention can be convenient, fast and determine wax molecular diffusivity exactly.
2, present invention also offers a kind of device measuring wax molecular diffusivity, this apparatus structure is simple, workable, has universality.
Accompanying drawing explanation
Fig. 1 is the length scanning collection of illustrative plates of wax molecular solution in embodiment 1.
Fig. 2 is the proving installation figure of wax molecular diffusivity.
Embodiment
For making the object, technical solutions and advantages of the present invention clearly, below in conjunction with the embodiment of the present invention, technical scheme of the present invention is clearly and completely described, obviously, described embodiment is the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.
Embodiment 1
A method of testing for wax molecular diffusivity, comprises the following steps:
1) n-C is adopted respectively
18, n-C
20, n-C
22, n-C
24, n-C
26for solute, normal heptane is solvent, preparation solute initial concentration (i.e. mole fraction) be 0.0012 each carrying object solution and solute initial concentration (i.e. mole fraction) be each pulse solution of (0.0012+0.002), wherein, the initial concentration difference of carrying object solution and pulse solution is 0.002.
2) before test, by above-mentioned steps 1) the carrying object solution for preparing carries out rinse to kapillary under the pump discharge of 0.100mL/min.
3) temporarily termination of pumping, open UV detecting device (model: LC-UV100, length scanning function down together), length scanning is carried out to described carrying object solution, the maximum absorption wavelength of carrying object solution is found from scanning spectra, wavelength within the scope of selection maximum absorption wavelength ± 5nm is as determined wavelength, and as shown in Figure 1, the determined wavelength that the present embodiment arranges UV detecting device is 200nm.
4) pump discharge is regulated to be 0.100mL/min, the carrying object solution being 0.0012 by initial concentration by high pressure constant flow pump (model: LC-P100) pumps in kapillary, by 20 μ L hand sampling valves, (PheodyneL.P. company produces again, model: 7725i) in kapillary, inject the pulse solution that initial concentration is (0.0012+0.002), then pulse solution spreads in the Laminar Flow formed at carrying object solution.
In the present embodiment, adopt n-C respectively
18, n-C
20, n-C
22, n-C
24, n-C
26for solute, normal heptane is solvent, and preparation solute initial concentration (i.e. mole fraction) is in the process of each carrying object solution of 0.0012, and its pump discharge is all set as 0.100mL/min, and therefore the flow of each carrying object solution in kapillary is all equal.
5) that detects solution in kapillary by UV detecting device washes out peak, and is gathered each parameter washing out peak by data collection task station, obtains wax molecular diffusivity by following formula:
D in formula
aBfor wax molecular diffusivity, m
2/ s; W
1/2for half-peak breadth, i.e. the half of whole appearance time, s; R is kapillary inside radius, m; t
rfor appearance time, s.
At 30 DEG C, test n-C by said method
18, n-C
20, n-C
22, n-C
24, n-C
26coefficient of diffusion, the results are shown in shown in table 1 of its coefficient of diffusion.Wherein, kapillary is positioned in water bath with thermostatic control carrys out regulating and controlling temperature.(note: carry out repeating experiment for 2-3 time to the test of coefficient of diffusion under each experiment condition, get the average as test result of experimental data.)
The wax molecular diffusivity of each solution at table 130 DEG C
In the present embodiment, kapillary used is length is 13.38m, and pipe inside radius r is the polyetheretherketone kapillary of 0.255mm, and the pump discharge of each carrying object solution is 0.100mL/min.Therefore, be diffused into the time t of outlet from capillary inlet corresponding to mean flow rate U and each solution in the pipe of each solution
r' be identical, be respectively 8.2mm/s and 1642.0s.Because joined each solution is lean solution, therefore at 30 DEG C, density and the viscosity of each solution can be assert approximate identical, known by testing: each solution is under 30 DEG C of conditions, and density p is 0.72g/cm
3, viscosities il is 0.67mPas.
As shown in Table 2: 1) Reynolds number of each carrying object solution in kapillary is all less than 2000, can form parabolic type Laminar Flow; 2) time being diffused into tube wall in each solution from kapillary center is less than the time being diffused into outlet from capillary inlet:
D in formula
aBfor wax molecular diffusivity, m
2/ s; R is kapillary inside radius, m; t
r' to be diffused into the time of outlet from capillary inlet for carrying object solution and pulse solution.
Table 2
Embodiment 2
Fig. 2 is the proving installation of wax dispersion coefficient of diffusion, and this device comprises: high pressure constant flow pump 1, kapillary 3, sampling valve 2, water bath with thermostatic control 4, UV detecting device 5, sump assemblies 6, data collection task station 7.
The transfusion outlet of sump assemblies 6 is connected with the import of high pressure constant flow pump 1; Wherein, sump assemblies 6 is for storing carrying object solution, and carrying object solution pump is sent in kapillary 3 by high pressure constant flow pump 1;
Be connected by the hand sampling valve 2 of 20 μ L between the outlet of high pressure constant flow pump 1 and the import of kapillary 3; Wherein, kapillary 3 is placed in water bath with thermostatic control 4, can be controlled the temperature of carrying object solution and pulse solution in kapillary 3 by the temperature of regulating thermostatic water-bath 4;
The outlet of kapillary 3 is connected with UV detecting device 5; Wherein, the signal accuracy of UV detecting device 5 is 10
-6au, baseline noise is no more than 5 × 10 for the methyl alcohol of 20 DEG C
-5au.
UV detecting device 5 connection data acquisition workstation 7; That detects solution in kapillary 3 by UV detecting device washes out peak, and is gathered each parameter washing out peak by data collection task station 7.
Last it is noted that above each embodiment is only in order to illustrate technical scheme of the present invention, be not intended to limit; Although with reference to foregoing embodiments to invention has been detailed description, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein some or all of technical characteristic; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the scope of various embodiments of the present invention technical scheme.
Claims (5)
1. a method of testing for wax molecular diffusivity, is characterized in that, described method of testing comprises the following steps:
1) carrying object solution is pumped in kapillary, again pulse solution is injected this kapillary, spread in the Laminar Flow that pulse solution is formed at carrying object solution, and control described carrying object solution and described pulse solution is diffused into tube wall time from kapillary center and be less than the time being diffused into outlet from capillary inlet;
Wherein, described carrying object solution and described pulse solution are the solution with identical solute and solvent, but there is solubility difference between two kinds of solution, described solute is have the n-alkane being not less than C17 carbon chain lengths, described solvent is have the hydro carbons, alcohols or the aromatic substance that are not more than C10 carbon chain lengths, further, the flow velocity of described carrying object solution forms Laminar Flow, meets following formula:
2rUρ/η≤2000
In formula, U is the flow velocity of carrying object solution, ms
-1; R is kapillary inside radius, m; ρ is the density of carrying object solution, kgm
-3; η is the kinetic viscosity of carrying object solution, Pas;
2) that detects solution in kapillary by UV detecting device washes out peak, obtains wax molecular diffusivity by following formula:
D in formula
aBfor wax molecular diffusivity, m
2/ s; W
1/2for half-peak breadth, s; R is kapillary inside radius, m; t
rfor appearance time, s.
2. method of testing according to claim 1, is characterized in that, also comprises before testing to the initialization of proving installation, comprising: adopt described carrying object solution carry out rinse to described kapillary and arrange the determined wavelength of UV detecting device.
3. method of testing according to claim 2, is characterized in that, the determined wavelength that UV detecting device is set described carrying object solution maximum absorption wavelength ± 5nm within the scope of.
4. method of testing according to claim 1, is characterized in that, described carrying object solution and described pulse solution are ± 0.1 based on the initial concentration difference of mole fraction.
5. method of testing according to claim 1, is characterized in that, the pump discharge that control carrying object solution pumps into kapillary is 0.001 ~ 0.999mLmin
-1.
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| CN113358423B (en) * | 2021-05-20 | 2023-03-14 | 合肥学院 | Quasi-continuous environment atmospheric gas sampling device |
| CN113984592A (en) * | 2021-11-04 | 2022-01-28 | 安徽江淮汽车集团股份有限公司 | Wax liquid penetration detection device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2148198A1 (en) * | 2008-07-21 | 2010-01-27 | Centre National de la Recherche Scientifique (CNRS) | Determination of the hydrodynamic radii and/or content of constituents of a mixture by analysis of the Taylor dispersion of the mixture in a capillary tube |
| CN103108701A (en) * | 2010-09-26 | 2013-05-15 | 大玉企业有限公司 | Separation of analytes |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2148198A1 (en) * | 2008-07-21 | 2010-01-27 | Centre National de la Recherche Scientifique (CNRS) | Determination of the hydrodynamic radii and/or content of constituents of a mixture by analysis of the Taylor dispersion of the mixture in a capillary tube |
| CN103108701A (en) * | 2010-09-26 | 2013-05-15 | 大玉企业有限公司 | Separation of analytes |
Non-Patent Citations (2)
| Title |
|---|
| "Diffusion coefficients for Binary，Ternary，and Polydisperse Solutions from Peak-Width Analysis of Taylor Dispersion Profiles";Rachel Callendar等;《Journal of Solution Chemistry》;20060505;第35卷(第3期);第353-379页 * |
| "利用泰勒分析和动态涂层毛细管电泳系统快速测定蛋白质的扩散系数";左敏等;《高等学校化学学报》;20071031;第28卷(第10期);第1875-1877页 * |
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