JP5202433B2 - Method and apparatus for measuring liquid properties - Google Patents

Description

  The present invention relates to a liquid property measuring method and apparatus, and more particularly to a liquid property measuring method and apparatus for measuring orientation polarization in a liquid.

  In a plant for processing oil such as petroleum refining, a method and an apparatus for measuring the physical properties of the oil are demanded in order to monitor changes in the physical properties of the oil over time and the fluctuations in the operating conditions associated therewith.

  Conventionally, as a method for measuring physical properties of liquids such as oil, a method using a refractive index and a method using a dielectric constant are known.

  As a method for measuring a liquid property using a refractive index, for example, Patent Document 1 proposes an oil type discrimination method and apparatus using a total reflection type refractive index sensor.

  In addition, as a method for measuring liquid physical properties using electrostatic permittivity, for example, in Patent Document 2, a potential difference is detected from a dielectric fluid that is electrically polarized by the energy of an electric field, so that a change in the component / normality of the dielectric fluid is detected. A method and apparatus for detection has been proposed.

Japanese Patent Laid-Open No. 08-114547 JP 2001-264291 A

  The inventor of the present application has inferred that permanent dipoles in the oil may affect the contamination of the oil, fluctuations in plant operating conditions, and the like during the study on the physical properties of the oil. For this reason, it is important to measure in real time the amount of permanent dipoles in the oil, that is, the orientation polarization, in order to monitor the quality control of the oil and the operating conditions of the plant.

  However, the refractive index is a physical quantity that represents the amount of measurement light interacting with electrons in the molecule. For this reason, the liquid property measurement method using the refractive index described above cannot measure the amount of orientation polarization in oil due to the molecular structure.

  In addition, the electrostatic dielectric constant is superimposed on the mechanism of orientation polarization, ion polarization, and electronic polarization. In order to separate these, the frequency of the voltage applied to the oil is wide, from low to light. I had to scan it. For this reason, the liquid property measurement method using the dielectric constant described above cannot measure the amount of orientation polarization in oil in real time.

  An object of the present invention is to determine whether or not the liquid to be measured has orientation polarization, and to provide a method and apparatus for measuring liquid properties that can quantitatively handle the orientation polarization if it has. There is to do.

The purpose is to measure the refractive index and relative dielectric constant of the liquid to be measured, where the measured refractive index of the liquid is n and the relative dielectric constant is ε _r , P = (ε _r −n ² ) / n This is achieved by a method for measuring liquid properties, wherein an index P that is an index for evaluating an orientationally polarized substance in the liquid is calculated from the relational expression ² .

In the above-described method for measuring liquid properties, the maximum value of the index is P _max , and the correction value when the index is a negative number is D, C = ((P + D) / (P _max + D)) × 100 The concentration C of the orientation polarization substance in the liquid may be calculated from the relational expression.

  In the liquid property measuring method described above, when the liquid is composed of a plurality of substrates, the maximum value of the index is the maximum value of the indexes of the plurality of substrates. Also good.

  In the liquid property measurement method described above, the temperature of the liquid is measured at the time of measuring the refractive index and the relative dielectric constant, and the measured values of the refractive index and the relative dielectric constant are set to the refractive index at a predetermined temperature. The index may be calculated after conversion into the relative dielectric constant.

Further, the object is to provide a refractive index measuring unit that measures the refractive index of the liquid to be measured, a relative dielectric constant measuring unit that measures the relative dielectric constant of the liquid, and the refractive index measured by the refractive index measuring unit. n, an index calculating means for calculating an index P that serves as an index for evaluating an orientationally polarized substance in the liquid, from the relational expression P = (ε _r −n ² ) / n ² , where ε _r is the relative dielectric constant; It is also achieved by a liquid property measuring apparatus characterized by having

In the liquid property measuring apparatus described above, C = ((P + D) / (P _max + D)) × 100 where P _{max is} the maximum value of the index and D is a correction value when the index is a negative number. You may make it further have a density | concentration calculation means which calculates the density | concentration C of the orientation polarization substance in the said liquid from a relational expression.

  In the liquid property measuring apparatus described above, the refractive index measuring unit and the relative dielectric constant measuring unit may be housed in the same container.

  According to the present invention, by measuring the refractive index and relative dielectric constant, it is possible to calculate an orientation polarization index that serves as an index of the presence of an orientation polarization substance in the liquid to be measured. Further, the concentration of the orientation polarization substance can be calculated from the calculated orientation polarization index. Moreover, in the measurement of the relative dielectric constant, it is only necessary to perform measurement at a specific frequency at which an orientation polarization component appears, and it is not necessary to scan the measurement voltage over a wide range. Thereby, the presence and the amount of the orientation polarization substance in the liquid to be measured can be easily measured in real time.

FIG. 1 is a graph showing the relationship between the relative permittivity and the refractive index of a material that does not contain an orientation polarization material. FIG. 2 is a graph showing the relationship between the relative dielectric constant and the refractive index of a material that does not contain an orientation polarization material and a material that contains an orientation polarization material. FIG. 3 is a graph showing the relationship between the orientation polarization index and the tetralin concentration in xylene. FIG. 4 is a schematic view showing an example of a liquid property measuring apparatus according to an embodiment of the present invention. FIG. 5 is a schematic view showing another example of a liquid property measuring apparatus according to an embodiment of the present invention. FIG. 6 is a flowchart illustrating a method for measuring liquid properties according to an embodiment of the present invention.

  A liquid property measuring method and apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a graph showing the relationship between the relative permittivity and the refractive index of a material that does not contain an orientation polarization material. FIG. 2 is a graph showing the relationship between the relative dielectric constant and the refractive index of a material that does not contain an orientation polarization material and a material that contains an orientation polarization material. FIG. 3 is a graph showing the relationship between the orientation polarization index and the tetralin concentration in xylene. FIG. 4 is a schematic diagram illustrating an example of a liquid property measuring apparatus according to the present embodiment. FIG. 5 is a schematic view showing another example of the liquid property measuring apparatus according to the present embodiment. FIG. 6 is a flowchart showing a method for measuring liquid properties according to the present embodiment.

The liquid property measuring method according to the present embodiment obtains an index (orientation polarization index) as an index of the content of the orientation polarization substance from the refractive index n and the relative dielectric constant ε _r of the sample oil to be measured, and the fluctuation of the index. From this, the concentration of the orientation polarization substance is obtained. The inventor of the present application newly found that this method enables measurement of an orientationally polarized substance in a short time, and has arrived at the present invention.

That is, the liquid property measuring method according to the present embodiment measures the refractive index n and the relative dielectric constant ε _r of the sample oil to be measured, calculates the index P from the following equation (1), and calculates the index P This is a method of calculating the concentration of the orientation polarization substance based on the above.

P = (ε _r −n ² ) / n ² (1)
In general, a material that does not include an orientation polarization material has a relationship of n ² = ε _r between the refractive index n and the relative dielectric constant ε _r . That is, in a substance that does not contain an orientation polarization substance, P in formula (1) is zero.

On the other hand, in a substance containing an orientation polarization substance, a component due to orientation polarization is superimposed on a relative dielectric constant ε _r in addition to a component due to electronic polarization, so (ε _r −n ² ) is not zero. Instead, a specific value corresponding to the amount of orientation polarization is shown. By dividing this value by the square of the refractive index and n ² and normalizing, the value of P in formula (1) can be made versatile and can be an industrially easy-to-handle index. .

  Therefore, the physical quantity P calculated by the equation (1) is a specific value representing the amount of orientation polarization of the orientation polarization substance contained in the sample oil to be measured. Therefore, in this specification, the variable P is referred to as “orientation polarization index”.

  The physical property meaning of the orientation polarization index P used in this embodiment will be described in more detail.

FIG. 1 is a graph showing the relationship between the relative dielectric constant ε _r and the refractive index n measured at a temperature of 40 ° C. for four types of sample oils that do not contain an orientation polarization substance. The Abbe refractometer (wavelength 589 nm) was used for the measurement of the refractive index. In the measurement of the relative dielectric constant epsilon _r, and the frequency of the measurement voltage is 100kHz. The horizontal axis represents the square of the refractive index, and the vertical axis represents the relative permittivity epsilon _r.

The measurement points in FIG. 1 (in the figure, ● marks) are those having a low relative dielectric constant ε _r , C10 normal paraffin (NP-C10 in the figure), C12 normal paraffin (NP-C12 in the figure), Decahydronaphthalene (decalin in the figure) and p-xylene (p-Xy in the figure) are shown.

As shown in the drawing, it can be seen that the square of the relative dielectric constant ε _r and the refractive index n in each sample oil shown in FIG. 1 is directly proportional. The regression line calculated from the data in FIG. 1 is represented by y = 0.87971x + 0.006, where x is the square of the refractive index n and y is the relative dielectric constant ε _r , and the correlation coefficient R is R = 0. 9894.

FIG. 2 is a graph showing the relationship between the relative dielectric constant ε _r measured at a temperature of 40 ° C. and the square of the refractive index n for four types of sample oil containing tetralin containing an orientationally polarized substance in addition to the data shown in FIG. It is. In the measurement of the relative dielectric constant epsilon _r, and the frequency of the measurement voltage is 100kHz.

The measurement points (marked with ▲ in the figure) of the four types of sample oil containing tetralin are those having a low relative dielectric constant ε _r , p-xylene 75%: tetralin 25% (p-Xy 75% in the figure: tetralin 25 %) Sample oil, p-xylene 50%: tetralin 50% (in the figure, p-Xy50%: tetralin 50%) sample oil, p-xylene 25%: tetralin 75% (in the figure, p-Xy25%: Sample oil of tetralin 75%) and tetralin 100% (tetralin in the figure).

As shown in the figure, the sample oil containing tetralin (in the figure, ▲) has a proportional relationship between the relative permittivity ε _r and the square of the refractive index n, but the sample oil in FIG. It can be seen that there is a large divergence from the regression line (, ●). In addition, the regression line calculated from the data of the sample oil containing tetralin is represented by y = 2.8303x−4.2126, where x is the square of the refractive index n and y is the relative dielectric constant ε _r , and the correlation coefficient R was R = 0.9848.

The relative dielectric constant ε _r is obtained by superimposing three mechanisms of electronic polarization, ionic polarization, and orientation polarization. The relationship between the relative dielectric constant ε _r and the square of the refractive index n in the sample oil containing tetralin is significantly different from the relationship in the sample oil not containing tetralin (n ² ≈ε _r ). This is because the component due to orientation polarization is superimposed in addition to the component due to electronic polarization found in the sample oil that is not present.

  As for a substance containing an orientation polarization substance, an on-sager formula represented by the following formula (2) is known as a formula for the dielectric constant of a polar liquid. In equation (2), μ is the permanent dipole moment of the substance, and N is the number of dipoles per unit volume.

  The sample oil handled in the present embodiment is a mixed oil composed of other substances. Since the permanent dipole moment μ differs depending on the substance, the mixed oil is expressed by the following equation (3) in the onsarger equation, but each Ni cannot be obtained from the equation (3).

  In the liquid property measuring method according to the present embodiment, attention is focused on the contribution of orientation polarization in the dielectric constant, not the value of the dielectric constant. Therefore, in the method for measuring liquid properties according to the present embodiment, the orientation polarization index P is calculated as an index representing the total orientation polarization amount from the equation (1).

  FIG. 3 is a graph showing the relationship between the tetralin concentration in xylene and the orientation polarization index P. The sample oils measured are those having a low orientation polarization index P, p-xylene 100% sample oil, p-xylene 75%: tetralin 25% sample oil, p-xylene 50%: tetralin 50% sample oil, 25% p-xylene: 75% tetralin sample oil, 100% tetralin sample oil.

  As shown in the figure, the result of plotting the orientation polarization index P and the concentration of tetralin in para-xylene has a correlation coefficient of 0.988 and can be approximated by a straight line. This indicates that the amount of the orientation polarization substance in the sample oil can be known from the orientation polarization index P. Further, from this orientation polarization index P, it can also be determined whether or not an orientation polarization substance having a permanent dipole moment exists in the sample oil. Furthermore, the formula (1) is very simple compared to the on-sager formulas (2) and (3) and is industrially easy to use.

  In the liquid property measuring method according to the present embodiment, the following formula (4) is used to calculate the concentration C of the orientation polarization substance from the orientation polarization index P.

C = ((P + D) / (P _max + D)) × 100 (4)
Here, D is a correction value for correcting the case where P is negative. That is, the correction value D is an absolute value of the value of the orientation polarization index P when no orientation polarization substance is included. For example, in the example of FIG. 3, D = 9. Since the correction value D varies depending on the sample oil to be measured, it is measured in advance.

P _max in the equation (4) is calculated by the following procedure. Here, as an example, consider a case where the sample oil is composed of three types of base materials: base material A, base material B, and base material C. For example, in the case of the sample oil of FIG. 2, it can be considered that the base material A which is p-xylene and the base material B which is tetralin are included. The number of base materials is not limited to 3, but may be 1 or 2, or 4 or more.

First, for each of the base material A, the base material B, and the base material C, the orientation polarization index P is measured using the formula (1). Here, orientation polarization index of the base material A is P _A, the orientation polarization index of the base material B is assumed P _B, the orientation polarization index of the base material C is P _C.

P _max, the orientation polarization index _{P A,} P B, the maximum value of _{P C.} When P _max varies depending on operating conditions such as raw materials, the orientation polarization index P is measured at regular intervals, and the maximum value among them is stored as the value of P _max .

By storing the correction value D and the maximum value P _max of the orientation polarization index in advance by the above procedure, the concentration C of the orientation polarization substance is calculated from the orientation polarization index P calculated from the measured value using the equation (4). Can be calculated.

  The concentration C calculated from the equation (4) represents a relative amount with respect to the amount of the orientation polarization substance contained in the specific base material as a percentage. The concentration C does not represent the absolute amount of the orientation polarization substance contained in the sample oil, but can be used as, for example, an index representing a change in the concentration of the orientation polarization substance.

  Next, a configuration example and operation of a measuring apparatus for realizing the liquid property measuring method according to the present embodiment will be described with reference to FIGS. 4 and 5.

  As shown in FIG. 4, a sample oil passage 10 provided in a measurement target device (not shown) includes a refractive index measurement unit 12 that measures the refractive index of the sample oil, and a relative dielectric constant of the sample oil. A relative dielectric constant measuring unit 14 for measuring and a temperature measuring unit 16 for measuring the temperature of the sample oil are provided.

  A refractive index temperature correction unit 18 is connected to the refractive index measurement unit 12 and the temperature measurement unit 16. Similarly, a relative dielectric constant temperature correction unit 20 is connected to the relative dielectric constant measurement unit 14 and the temperature measurement unit 16.

  An orientation polarization index calculation unit 22 is connected to the refractive index temperature correction unit 18 and the relative dielectric constant temperature correction unit 20.

  Sample oil can be passed through the sample oil passage 10 as indicated by arrows in the figure. The refractive index, relative dielectric constant, and temperature of the sample oil introduced into the sample oil passing part 10 are the refractive index measuring part 12, the relative dielectric constant measuring part 14, and the temperature measuring part provided in the sample oil passing part 10. 16 can be measured.

  A refractive index temperature correction unit 18 is connected to the refractive index measurement unit 12 and the temperature measurement unit 16, and a specific temperature based on the temperature measured by the temperature measurement unit 16 by the refractive index temperature correction unit 18. Can be converted into a refractive index. Similarly, a relative dielectric constant temperature correction unit 20 is connected to the relative dielectric constant measurement unit 14 and the temperature measurement unit 16, and the temperature measured by the temperature measurement unit 16 is adjusted by the relative dielectric constant temperature correction unit 20. Based on this, it can be converted into a relative dielectric constant at a specific temperature.

  The refractive index temperature correction unit 18 and the relative dielectric constant temperature correction unit 20 are connected to an orientation polarization index calculation unit 22. The refractive index at a specific temperature calculated by the refractive index temperature correction unit 18 and the relative dielectric constant are calculated. The orientation polarization index P can be calculated from the relative dielectric constant at a specific temperature calculated by the temperature correction unit 20 for the rate.

5 further includes an alignment polarization substance concentration calculation unit 24 connected to the alignment polarization index calculation unit 22, and an alignment polarization index P _max recording unit connected to the alignment polarization substance concentration calculation unit 24. 26 is provided.

Thereby, from the orientation polarization index P calculated by the orientation polarization index calculation unit 22 and the maximum value P _max of the orientation polarization index recorded in the orientation polarization index P _max recording unit 26, the concentration of the orientation polarization substance contained in the sample oil C can be calculated.

  The measured values of the refractive index and relative dielectric constant of the sample oil are temperature-corrected based on the temperature measured by the temperature measuring unit 16 in the sample oil passing unit 10. Therefore, in the measuring apparatus of FIGS. 4 and 5, it is desirable that the refractive index measuring unit 12, the relative dielectric constant measuring unit 14, and the temperature measuring unit 16 be installed as close as possible in the sample oil passing unit 10. .

  When the temperature measurement unit 16 cannot be disposed near both the refractive index measurement unit 12 and the relative dielectric constant measurement unit 14 such as when the refractive index measurement unit 12 and the relative dielectric constant measurement unit 14 are separated from each other. The temperature measuring unit 16 may be provided for the refractive index measuring unit 12 and the relative dielectric constant measuring unit 14, respectively. From the viewpoint of simplifying the apparatus, it is desirable to install the refractive index measuring unit 12, the relative dielectric constant measuring unit 14, and the temperature measuring unit 16 in the same container as in this embodiment.

  Next, an example of a measurement flow using the measurement apparatus of FIGS. 4 and 5 will be described with reference to FIG.

First, prior to the measurement of the sample oil, the maximum value P _max of the orientation polarization index is calculated and recorded in the orientation polarization index P _max recording unit 26 (step S11). Specifically, for each base material constituting the sample oil, the orientation polarization index P is calculated by the equation (1), and the largest orientation polarization index P is set as the maximum value P _max of the orientation polarization index. The calculation method of the orientation polarization index P of each substrate is performed in the same manner as steps S12 to S14 shown below.

When the maximum value P _max of the orientation polarization index changes depending on the operating conditions such as the raw material, it is desirable to measure the orientation polarization index P at regular intervals and store the maximum value as the value of P _max .

  Note that step S11 is not necessary in the measurement using the measurement apparatus of FIG.

Then, by introducing the sample fluid into the sample through the oil unit 10, the temperature T _m of a sample _oil, the refractive index n _m and the dielectric constant epsilon _m, the temperature measuring unit 16, the refractive index measuring unit 12 and the relative dielectric constant measuring unit 14, each is measured (step S12).

  The measurement of the refractive index n is not particularly limited, but for example, prism glass using an optical waveguide can be used. As the light source, a semiconductor laser such as GaAs-AlGaAs (wavelength 0.85 μm), an Na lamp (wavelength 589 nm), a He—Ne laser (wavelength 632.8 nm), a light emitting diode (LED), or the like can be used.

Light is incident from one end of the prism glass, and the pattern of light reflected from the portion where the prism glass and sample oil are in contact with each other is measured with a one-dimensional CCD array. When the reflected light is measured with a prism glass using a glass having a refractive index larger than that of the sample oil, the pattern has a bright portion and a dark portion, and a boundary portion clearly appears. Therefore, the reflection angle θ _m that becomes the light / dark boundary is calculated. Since the reflection angle θ _m corresponds to the total reflection critical angle θ _c , the refractive index n of the sample oil can be calculated from the critical angle θ _c according to Snell's law. In the refractive index measurement using the prism glass, the sample oil does not need to be transparent, and the refractive index can be measured with high accuracy even when the oil is black and opaque.

The measurement of the relative dielectric constant ε _r is not particularly limited, but can be calculated from the ratio of the electric capacities of the sample oil and air measured by parallel plate electrodes. In the definition of relative permittivity, the substance for which the ratio to the sample is determined is not air but vacuum, but the permittivity of air and vacuum is considered to be approximately the same as the permittivity of sample oil. The electric capacity _CE of the sample oil can be calculated from the following equation (5). Here, S is an electrode area, and d is an electrode interval. Since measurement becomes difficult when the electric capacity is small, it is desirable to make the size of the parallel plate electrode appropriate for engineering. In order to obtain a stable measurement value for the relative dielectric constant ε _r , it is desirable to use an AC signal, and it is desirable to use a frequency band in which a component due to dielectric polarization is superimposed on the measurement value, for example, 80 kHz to 3 GHz.

C _E = ε ₀ ε _r S / d (5)
From the viewpoint of performing measurement while continuously passing sample oil, it is desirable to arrange a prism glass plate for refractive index measurement and a parallel plate electrode for dielectric constant measurement so that the sample oil flows smoothly.

Then calculated from the measured refractive index _{n m} and the dielectric constant epsilon _m, the refractive index _{n c} and the relative dielectric constant epsilon _c in a temperature _{T c} that is determined in advance (step S13).

Specifically, the temperature correction part 18 of the refractive index, using a temperature coefficient of refractive index, from the value of the measured temperature T _m and the refractive index n _m, calculates the refractive index n _c at a temperature T _c. Similarly, the relative permittivity temperature correction section 20 calculates the relative permittivity ε _c at the temperature T _c from the measured temperature T _m and relative permittivity ε _m using the temperature coefficient of the relative permittivity. . Here, the temperature _{Tc to be} corrected is set to 40 ° C., for example.

We are doing the temperature compensation for the refractive index n _m and the dielectric constant epsilon _m, or when the temperature of the measurement of temperature and the dielectric constant epsilon _m of the measurement of the refractive index n _m are different, the refractive index Considering the case where the temperature T _m when measuring _nm and the relative dielectric constant ε _m and the temperature when measuring the maximum value P _max of the orientation polarization index are different. By performing the temperature correction of the refractive index n _m and the dielectric constant epsilon _m, it is possible to reduce the measurement error of the orientation polarization index P and concentration C calculated based on these.

Then, the orientation polarization exponent calculation unit 22, and the refractive index n _c calculated by the temperature correction part 18 of the refractive index, and a relative dielectric constant epsilon _c calculated by the temperature correction part 20 of the dielectric constant, the equation (1) An orientation polarization index P is calculated (step S14).

  Based on the value of the calculated orientation polarization index P, it can be determined whether or not the orientation polarization substance is contained in the sample oil. For example, when the orientation polarization index P is equal to or greater than a predetermined value, it is determined that the sample oil contains an orientation polarization substance, and the calculated value of the orientation polarization index P and the predetermined value are determined. The presence or absence of the alignment polarization substance can be determined by comparison with

  In the measurement apparatus shown in FIG. 4, a series of measurement processes is completed by the above step S14. Thereafter, the process returns to step S12 as necessary, and the orientation polarization index P is repeatedly measured.

Next, the maximum value P _max of the orientation polarization index calculated in advance and stored in the orientation polarization index P _max recording unit 26 and the orientation polarization index P calculated by the orientation polarization index calculation unit 22 are expressed by the equation (4). to calculate the concentration _{C m} of orientation polarization material (step S15).

Next, the calculated orientation polarization substance concentration C _m is compared with an orientation polarization substance concentration alarm threshold value C _T stored in advance (step S16). The threshold value C _T can be determined from the allowable range, etc. of the physical properties of the sample oil to be determined empirically.

If the measured concentration C _m is greater than or equal to the threshold value C _T , it is determined that the concentration of the oriented polarization substance in the sample oil has increased and deviated from the allowable range, and an alarm is issued to alert the plant operation ( Step S17). Alternatively, if the measured density C _m is equal to or smaller than the threshold C _T, it is determined that the concentration of the orientation polarization substances in the sample oil deviates from the allowable range decreases, may be alarm the alarm.

When the concentration C _m of the orientation polarization substance in the sample oil is C _m > 0, the voltage for measuring the relative permittivity in the relative permittivity measuring unit 14 is not applied continuously but intermittently. You may make it apply to. Further, if the sample oil concentration C _m of orientation polarization material in is equal to or greater than the threshold C _T, the orientation polarization measurement interrupted, the prism glass electrode and the refractive index measurement of the dielectric constant measurement contact You may make it let the liquid which wash | cleans a liquid part permeate | transmit for a predetermined time.

  These are oriented polar substances because the polarizable substances present in the sample oil are attracted and adhered to the electrodes for measuring the dielectric constant, and the wetted part of the prism glass for measuring the refractive index has polarity. This is because dirt may be generated in the measurement part due to the adhesion of to the glass surface. This is because the dirt obstructs the orientation polarization measurement, so that the accuracy of the orientation polarization measurement is reduced or becomes impossible to measure.

In the measurement apparatus shown in FIG. 5, a series of measurement processes is completed in step S17. Thereafter, the process returns to step S11 or step S12 as necessary, and the orientation polarization index P and the concentration _Cm are repeatedly measured. The orientation polarization index P and a concentration C _m By trend management, it is possible to quickly cope with a sudden change in property change and the operating conditions of the sample oil.

  Thus, according to the present embodiment, the orientation polarization index serving as an index of the presence of the orientation polarization substance in the liquid to be measured can be calculated by measuring the refractive index and the relative dielectric constant. Further, the concentration of the orientation polarization substance can be calculated from the calculated orientation polarization index. Moreover, in the measurement of the relative dielectric constant, it is only necessary to perform measurement at a specific frequency at which an orientation polarization component appears, and it is not necessary to scan the measurement voltage over a wide range. Thereby, the presence and the amount of the orientation polarization substance in the sample oil can be easily measured in real time.

[Modified Embodiment]
The present invention is not limited to the above embodiment, and various modifications are possible.

  For example, in the above embodiment, as a use example in a plant for processing oil such as petroleum refining, the liquid to be measured is oil, but the liquid to be measured is not limited to oil. The liquid property measuring method and apparatus of the present invention can be applied to the measurement of various liquids having orientation polarization.

  In the above-described embodiment, the temperature correction of the refractive index and the relative dielectric constant measured from the viewpoint of improving the measurement accuracy is performed, but the temperature correction of the refractive index and the relative dielectric constant is not necessarily required. For example, when the variation of the temperature of the sample oil in the sample oil passage 10 is small, the orientation polarization index P may be calculated using the measured values of the refractive index and the relative dielectric constant as they are.

DESCRIPTION OF SYMBOLS 10 ... Sample oil-passing part 12 ... Refractive index measuring part 14 ... Relative permittivity measuring part 16 ... Temperature measuring part 18 ... Refractive index temperature correcting part 20 ... Relative permittivity temperature correcting part 22 ... Orientation polarization index calculating part 24 ... Orientation polarization index P _max recording unit 26... Orientation polarization substance concentration calculation unit

Claims (7)

Measure the refractive index and relative dielectric constant of the liquid to be measured,
The measured refractive index of the liquid is n, and the relative dielectric constant is ε _r .
P = (ε _r −n ² ) / n ²
An index P serving as an index for evaluating an orientationally polarized substance in the liquid is calculated from the relational expression: The liquid property measuring method according to claim 1,
The maximum value of the exponent is P _max , and the correction value when the exponent is a negative number is D,
C = ((P + D) / (P _max + D)) × 100
The concentration C of the orientation polarization substance in the liquid is calculated from the relational expression. In the measuring method of the liquid physical property of Claim 2,
The liquid is composed of a plurality of base materials,
The maximum value of the index is the maximum value of the indexes of each of the plurality of base materials. In the liquid physical property measuring method according to any one of claims 1 to 3,
The temperature of the liquid is measured at the time of measuring the refractive index and the relative dielectric constant, and the measured values of the refractive index and the relative dielectric constant are converted into the refractive index and the relative dielectric constant at a predetermined temperature. A method for measuring liquid properties, characterized by calculating an index. A refractive index measuring unit for measuring the refractive index of the liquid to be measured;
A relative permittivity measurement unit for measuring the relative permittivity of the liquid;
The refractive index measured by the refractive index measuring unit is n, and the relative dielectric constant is ε _r .
P = (ε _r −n ² ) / n ²
And an index calculating means for calculating an index P which is an index for evaluating the orientationally polarized substance in the liquid. The liquid property measuring apparatus according to claim 6,
The maximum value of the exponent is P _max , and the correction value when the exponent is a negative number is D,
C = ((P + D) / (P _max + D)) × 100
A liquid property measuring apparatus, further comprising: concentration calculating means for calculating the concentration C of the orientationally polarized substance in the liquid from the relational expression: In the liquid physical property measuring apparatus according to claim 5 or 6,
The liquid property measuring apparatus, wherein the refractive index measuring unit and the relative dielectric constant measuring unit are housed in the same container.

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