JP2963346B2 - Lubricating oil deterioration detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting the degree of deterioration or remaining life of various lubricating oils such as engine oil, compressor oil and gear oil, and more particularly to a gas engine for a cogeneration system (CGS). The present invention relates to an oil deterioration detection method suitable for detecting the degree of deterioration or remaining life of engine oil (hereinafter, referred to as "gas engine oil") used.

[0002]

2. Description of the Related Art For example, a cogeneration system (CGS)
Gas engine oil is used as a lubricating oil for a gas engine for use, but deteriorates by use, similarly to normal engine oil.

[0003] There is a need to maintain the CGS and extend the life of the engine, and it is important to manage the lubrication of the gas engine oil. Heretofore, conventional petroleum test methods such as the JIS method, the Japan Petroleum Institute method, and the ASTM method have been used for lubrication management of gas engine oils. Specifically, a general total acid value, a total base number, an insoluble content, a viscosity, and the like are measured, a degree of deterioration of the gas engine oil is detected, and a degree of deterioration is determined.

However, these test methods are highly reliable, but all are wet analyses, require on-site batch sampling, and the analysis is usually performed in a laboratory, and the current state of oil is rapidly increased. Can not give the result of
There was a drawback that it was not possible to constantly monitor online detection.

In order to solve such conventional problems, various degradation sensors for online use have been studied and proposed. For example, a sensor using the principle of infrared spectroscopy in the mid-infrared region (2.5 to 25 μm) or a single wavelength light in the visible and near infrared region (0.4 to 2.5 μm) is applied. There is a light transmission type sensor and the like. However, at present there is nothing practical.

[0006] The reason for this is that a sensor using the principle of infrared spectroscopy requires a large stabilized power supply for the light source, which causes a problem that the device becomes large, and that the optical path length needs to be extremely short. In addition to having the problem of the equipment being expensive in terms of cost, it is specially designed to detect the absorption of 6.1 μm or the vicinity of 5.8 μm by the nitrate ester which increases with the deterioration of oil due to the measurement principle. This is because there is a problem that a special spectral filter is required.

On the other hand, although there are some reports on a method using light in the visible and near-infrared region, the present inventors have also conducted research and found that, for example, by measuring the absorbance or the amount of transmitted light by a light transmission method, for example, It has been found that a good correlation can be found between the absorbance and the degree of oil deterioration (total acid number, insoluble matter, total base number or deterioration index defined by these) by determining the engine and oil type. Was. However, when such restrictions are removed, it has been found that there is a variation in a large-sized gas engine for CGS or the like, which deteriorates relatively quickly, and it is difficult to diagnose a general-purpose deterioration as it is.

[0008]

The inventors of the present invention have analyzed the causes of the above-mentioned problems by chemical analysis. As a result, the cause of the variation is that the pattern of oil deterioration depends on the engine, operating conditions, and the type of lubricating oil. , Because of the other effects, the degradation products in the oil changed, which led to the inference that the degree of oil degradation was due to the change in light absorbance even if the same result was obtained in wet analysis. . That is, the deterioration of the gas engine oil during use in the engine is unavoidable. However, this deterioration depends on the manner of progress of the deterioration, ie, early type deterioration (A), intermediate type deterioration (B), and late type deterioration ( When roughly classified as C), it was inferred that the used deteriorated oil was classified into any of these.

Then, in order to confirm the inference of the present inventors, a spectrum analysis of the used degraded oil was performed by visible / near infrared spectroscopy. As a result, it was verified that the three were clearly separated.

Further, the present inventors have conducted many research experiments to find a method of easily separating these three from the spectrum, and found that the absorbance of both the long wavelength side and the short wavelength side of each oil used was high. Was found, and when the values were plotted on the xy coordinates, it was found that the deterioration pattern was divided into the above three from the coordinates of the individual oils.

From the above, in designing an online sensor,
Using two light sources, a long wavelength and a short wavelength, the absorbance or the amount of transmitted light of the test oil is detected at the two wavelengths, and the deterioration patterns A, B, and C are identified therefrom, and then one of the two wavelengths is detected. It was concluded that correct deterioration determination of the used oil can be made by determining the degree of deterioration using the absorbance or the amount of transmitted light and the calibration curve corresponding to each pattern.

When this verification was performed analytically, 9
It has been proved that the deterioration pattern can be identified with a probability of 5% or more and the degree of deterioration can be determined.

The present invention has been made as a result of the inventors' novel findings and research and experiments based thereon.

Accordingly, an object of the present invention is to determine the degree of deterioration or remaining life during use of a lubricating oil for a gas engine for a cogeneration system (CGS) (gas engine oil), and various other lubricating oils, particularly, on-line. It is an object of the present invention to provide a method for detecting deterioration of lubricating oil which can be correctly detected and determined.

[0015]

The above object is achieved by a method for detecting deterioration of a gas engine oil according to the present invention. In summary, the present invention measures the absorbance or the amount of transmitted light at each wavelength of the lubricating oil using two lights of short wavelength and long wavelength in the range of 0.4 to 2.5 μm, and judges from the measured values. An algorithm for identifying the deterioration pattern of the lubricating oil, and then determining the degree of deterioration of the lubricating oil from the absorbance or the transmitted light amount of a specific wavelength and the calibration curve of each stored deterioration pattern. This is a deterioration detection method.

According to another aspect of the present invention, the short- and long-wavelength absorbances of the lubricating oil are obtained from an xy diagram having the short-wavelength and long-wavelength absorbance or transmitted light quantity as the x-axis and the y-axis, respectively. Alternatively, the deterioration pattern is determined based on the position of the transmitted light in the figure, and the degree of deterioration of the lubricating oil is obtained from the calibration curve corresponding to the pattern and the absorbance or transmitted light on the short wavelength side. A detection method is provided.

Further, according to another aspect of the present invention, a 0.4
Measure the absorbance or the amount of transmitted light at each wavelength of the lubricating oil using two lights of short wavelength and long wavelength in the range of ~ 2.5 μm, identify the deterioration pattern of the lubricating oil by the judgment algorithm from this measurement value, Then, a method for detecting the deterioration of the lubricating oil is characterized in that the remaining life (L) of the lubricating oil is obtained from the absorbance or the transmitted light amount of the specific wavelength and the calibration curves of the respective stored deterioration patterns based on the following equation. Provided. Remaining life (L) = {(Q ₁ −Q _X ) / (Q ₁ −Q ₀ )} × 10
0 (%) wherein, Q ₁ is the absorbance or the transmitted light amount of the lubricating oil at the time of the condition to be exchanged, Q ₀ is the absorbance or the transmitted light amount of the lubricating oil at the time of new oil, the absorbance of the lubricating oil at the time the Q _X in Or, on the calibration curve, the remaining life (L ₁ ) when the absorbance or the transmitted light quantity Q ₁ is 0%, and the remaining life (L ₀ ) when the absorbance or the transmitted light quantity Q ₀ is 100%. And

In this embodiment, when the lubricating oil is gas engine oil, the operating time and / or the integrated power generation of the gas engine and the absorbance of the gas engine oil that fluctuates with time are stored in a data table. The remaining life can be output as the remaining operating time (H) or the remaining generated power (P), which is stored and based on the data table from the absorbance obtained by actually detecting deterioration, based on the data table. Remaining operation time _{(H) = {(Q 1} -Q X) / (Q X -Q 0)}
× H _X (h) Residual generated power (P) = {(Q ₁ −Q _X ) / (Q _X −Q ₀ )}
× P _X (kWh) where Q ₁ is the absorbance or transmitted light amount of the lubricating oil in the state to be replaced, Q ₀ is the absorbance or transmitted light amount of the lubricating oil at the time of new oil, and Q _X is the lubricating oil at a certain point in time. a of the absorbance or the transmitted light quantity, also, H _X is Sarayu after a running time until when detecting deteriorated, P _X is the Sarayu after power generated until when detecting deteriorated.

In each of the above embodiments of the present invention, preferably, the wavelength within the range of 0.45 to 0.7 μm is set to the short wavelength.
A long wavelength within the range of 0.8 μm to 1.1 μm is used. Further, when the lubricating oil is gas engine oil, the deterioration pattern of the lubricating oil is the initial type deterioration (A),
Intermediate mold deterioration (B) and late mold deterioration (C) are employed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments with reference to the accompanying drawings.

Embodiment 1 FIG. 1 shows an embodiment of a two-wavelength oil deterioration sensor for implementing the method for detecting deterioration of lubricating oil according to the present invention. In this embodiment, the present invention relates to a cogeneration system (C
A description will be given of a case where the present invention is executed to detect the degree of deterioration of gas engine oil used in a gas engine for GS).

According to this embodiment, the oil deterioration sensor
Light-emitting unit 2 and light-receiving unit 3 opposed to each other across transparent cell 1
And A lubricating oil, that is, a gas engine oil in use in this embodiment, is introduced into the transparent cell 1. The light of a predetermined wavelength emitted from the light emitting unit 2 is irradiated on the gas engine oil in the transparent cell 1, the light transmitted through the gas engine oil is received by the light receiving unit 3, and the absorbance or transmitted light amount of the light transmitted by the gas engine oil is reduced. Measured.

The light emitting section 2 uses an LED or a laser diode as a light source and is driven by a driving section 4 to emit light of a predetermined wavelength. According to the present invention, the light emitting unit 2
Includes first and second light sources 2A and 2B, each of which has a.
It emits two lights of short wavelength and long wavelength in the range of 4 to 2.5 μm. Preferably, short wavelengths have wavelengths in the range of 0.45 to 0.7 μm and long wavelengths have 0.8 μm to 1.1 μm.
Wavelengths in the range of m are used. In the present embodiment, the first light source 2A is a light emitting diode having a center wavelength of 0.66 μm (660 nm), and the second light source 2B is a light emitting diode having a center wavelength of 0.66 μm (660 nm).
The light emitting diode has a center wavelength of 92 μm (920 nm). Further, a photodiode or the like is used for the light receiving unit 3 for receiving the light from the light emitting unit 2, and in the present embodiment, the first and second light sources 2A and 2B of the light emitting unit 2 correspond to the first and second light sources. Second photodiodes 3A and 3B are arranged. The light transmitted through the gas engine oil is received by the photodiodes 3A and 3B, and is converted into an electric signal corresponding to the absorbance or the amount of transmitted light in the light amount detection unit 5. Two photodiodes of the same type may be used as the photodiodes 3A and 3B as long as they detect both short wavelengths and long wavelengths. In this case, an optical system having a structure in which the light from the light source 2A and the light from the light source 2B can be focused on one photodiode can be provided.
In this case, only one photodiode is required.

Further, the electric signal from the light amount detecting section 5 is transmitted to a microcomputer 6 and converted into a pulse number which can be processed by the microcomputer (A / D conversion).
After that, it is input to the arithmetic unit of the microcomputer 6.

In the operation section of the micro computer, FIG.
Based on the signal from the light amount detection unit, a deterioration pattern indicating the current degree of deterioration of the gas engine oil is identified by a built-in determination algorithm as shown in FIG. Further, in the judgment algorithm, the degree of deterioration of the gas engine oil is calculated from the calibration curve corresponding to each of the identified deterioration patterns, and is output. This output signal is displayed on a display device.

Next, the determination algorithm will be described.

FIG. 3 shows the progress of the deterioration of the gas engine oil in use by the algorithm at 920 nm and 660 nm.
An example in which three patterns of early type deterioration (A), intermediate type deterioration (B), and late type deterioration (C) can be divided from the absorbance of nm is shown.

In the present embodiment, the absorbance is set at an optical path length of 0.1.
It is a value measured using a quartz cell of mm.

FIG. 4 shows an example in which the degree of deterioration (degradation index) of oil is output from three calibration curves by an algorithm. Here, the deterioration index is an index that comprehensively indicates the deterioration of the gas engine oil. The deterioration index is arbitrary based on the results of deterioration analysis based on the JIS method total acid value and the Japan Petroleum Institute method B insoluble matter (pentane), which have been used in the past. In this example, the index is defined as total acid value + n * insoluble (n = 7).

Therefore, when implementing the method for detecting the deterioration of gas engine oil according to the present embodiment, as can be understood from FIG. 2, the absorbance of gas engine oil (or the absorbance of gas engine oil using two lights of 660 nm and 920 nm). The amount of transmitted light is measured, and the deterioration patterns A, B, and C of the gas engine oil are identified from the measured values by the above-described algorithm.

In other words, for example, 660 nm and 920 n
The short and long wavelengths of the lubricating oil are obtained from the xy diagram (FIG. 3) in which the absorbance or the transmitted light amount of both the short and long wavelengths such as m is measured on the x and y axes, respectively. For example, the deterioration patterns A, B, and C are determined based on the position of the absorbance or transmitted light amount in the figure.

The microcomputer 6 stores the relationship between the 660 nm shown in FIG. 4 and the calibration curves 1, 2, and 3 of the respective deterioration patterns. Therefore, in the judgment algorithm, the absorbance at the wavelength of 660 nm (or the amount of transmitted light) is stored. ) And the calibration curves 1, 2, and 3 of the respective deterioration patterns stored in the memory, and the degree of deterioration (deterioration index) of the gas engine oil.
Is displayed on the display device 7.

In the embodiment shown in FIG. 4, oils (gas engine oils) 1, 2, and 3 have deterioration patterns A, B,
C and the degradation pattern calibration curves 1, 2, 3
The degree of deterioration (deterioration index) N ₁ , N ₂ , N
₃ is obtained and the degree of deterioration is determined.

Embodiment 2 Further, according to the second embodiment of the present invention, the microcomputer 6 can include the following judgment algorithm.

FIG. 5 shows the deterioration pattern A of the gas engine oil.
4 shows the relationship between the total acid value and the absorbance at 660 nm. Both are in good correlation. Regarding this deterioration pattern A, the total acid value greatly increases with the progress of deterioration as a characteristic of the oil, but the insoluble content increases slowly, and the total acid value is an important factor. On the other hand, the total base number is inversely correlated with the total acid number, and the deterioration diagnosis can be performed by outputting the total acid number with the deterioration sensor.

FIG. 6 shows the relationship between the absorbance at 660 nm and the insoluble content for the deterioration patterns B and C of the gas engine oil. It can be seen that both have a good correlation. In these two deterioration patterns B and C, the increase in the insoluble content due to the deterioration is large, but the increase in the total acid value is slow. Therefore, deterioration diagnosis can be performed by outputting an insoluble component by the deterioration sensor.

Therefore, in this embodiment, as understood from FIGS. 2 and 3,
The absorbance (or the amount of transmitted light) of the gas engine oil is measured using the two lights of 0 nm and 920 nm, and the deterioration patterns A, B, and C of the gas engine oil are identified from the measured values by the above determination algorithm.

In this embodiment, the microcomputer 6
5 and 6, a calibration curve 4 of the relationship between the total acid value and the absorbance at 660 nm for the degradation pattern A,
Calibration curves 5 and 6 for the relationship between the absorbance at 660 nm and the insoluble content for the degradation patterns B and C are stored. Therefore, according to this embodiment, in the determination algorithm, the deterioration patterns A, B, and C are identified for the oils (gas engine oils) 4, 5, and 6 in the same manner as in the above-described embodiment. As shown in FIG. 5, the degree of deterioration is obtained from the total acid value based on the deterioration pattern calibration curve 4, and the degree of oil deterioration is determined. On the other hand, for the oils 5 and 6, as shown in FIG. 6, the degree of deterioration is obtained from the insoluble components by the deterioration pattern calibration curves 5 and 6, and the degree of oil deterioration is determined.

As described above, the judgment algorithm first identifies the oil deterioration pattern in three ways, A, B, and C, and outputs the deterioration index and insoluble content for the deterioration patterns B and C by calculation, and outputs the deterioration pattern. A can have a function of calculating and outputting the deterioration index and the total acid value.

With respect to the first and second embodiments, a microcomputer having the above-described determination algorithm was actually manufactured.
Using this, a deterioration detection method for gas engine oil was implemented. Table 1 shows the results of confirming the performance. As can be seen from Table 1, the deterioration index obtained from the actually measured analysis value and the deterioration index obtained in the present invention are in good agreement within the error range. On the other hand, the total acid value obtained by the analysis and the total acid value obtained in the present invention, and the insoluble content obtained from the analysis values and the insoluble content obtained in the present invention are in good agreement.

As described above, according to the method for detecting deterioration of gas engine oil of the present invention, regardless of the type of oil and the type of engine,
It was proved that the deterioration of gas engine oil was correct and could be diagnosed.

[0042]

[Table 1]

Embodiment 3 In Embodiments 1 and 2 described above, the case where the deterioration detection method of the present invention is applied to detect the degree of deterioration of gas engine oil used in a gas engine for a cogeneration system (CGS) is described. As described above, according to the present invention, the remaining life (L) can be obtained instead of the deterioration degree of the lubricating oil.

That is, 0.4 to 2..
Using two lights of short wavelength and long wavelength in the range of 5 μm, for example, using two lights of 660 nm and 920 nm, the absorbance (or transmitted light amount) of the gas engine oil is measured. The deterioration patterns A, B, and C of the gas engine oil are identified.

Next, the remaining life (L) of the lubricating oil can be obtained from the absorbance or the transmitted light amount of the specific wavelength and the calibration curves of the stored deterioration patterns based on the following equation. Remaining life (L) = {(Q ₁ −Q _X ) / (Q ₁ −Q ₀ )} × 10
0 (%) Here, as shown in FIG. 7, Q ₁ is the absorbance or the transmitted light quantity, Q _X of the absorbance or the transmitted light quantity, Q ₀ is the lubricating oil at the time of new oil of the lubricating oil at the time of the condition to be exchanged It is the absorbance or transmitted light amount of the lubricating oil at the time. On the calibration curve, the remaining life (L ₁ ) at the absorbance or the transmitted light quantity Q ₁ is set to 0%, and the remaining life (L ₀ ) at the absorbance or the transmitted light quantity Q ₀ is set to 100%.

Further, when the lubricating oil is gas engine oil, the operating time and / or integrated power generation of the gas engine and the absorbance of the gas engine oil that fluctuates with time are stored as a data table, and the actual deterioration is performed. It is also possible to output the remaining life as the remaining operation time (H) or the remaining generated power (P) obtained from the following table based on the data table from the absorbance obtained by detection. Remaining operation time _{(H) = {(Q 1} -Q X) / (Q X -Q 0)}
× H _X (h) Residual generated power (P) = {(Q ₁ −Q _X ) / (Q _X −Q ₀ )}
× P _X (kWh) Here, Q ₁ , Q ₀ , and Q _X are as described above, and H _X
Is the operating time after oil change until the deterioration is detected, and P _X
Is the generated power after oil renewal up to the time when deterioration is detected.

In the description of each of the above embodiments, the case where the present invention is implemented to detect the degree of deterioration or remaining life of the gas engine oil used in the gas engine for the cogeneration system (CGS) has been described. The present invention is not limited to this, and can be applied to the detection of deterioration of various other lubricating oils, and can provide the same effects. Further, the deterioration pattern of the lubricating oil is not limited to the above-described deterioration patterns A, B, and C depending on the engine and the oil type, and any pattern can be adopted.

[0048]

As described above, the method for detecting deterioration of a lubricating oil according to the present invention employs two light beams having a short wavelength and a long wavelength in the range of 0.4 to 2.5 .mu.m. Measure the absorbance or transmitted light amount of the oil, identify the deterioration pattern of the lubricating oil from the measured value by the judgment algorithm, and then determine the lubrication from the absorbance or transmitted light amount of the specific wavelength and the calibration curve of each stored deterioration pattern. Determine the degree of deterioration of the oil or the remaining life, or from the xy figure with the x-axis and y-axis the absorbance or transmitted light quantity of both short wavelength and long wavelength, the short wavelength of the lubricating oil to be detected and The deterioration pattern is determined based on the position of the long-wavelength absorbance or transmitted light in the figure, and the degree of deterioration of the lubricating oil is determined from the calibration curve corresponding to the pattern and the short-wavelength absorbance or transmitted light. Since it is configured to determine the service life,
The deterioration of various lubricating oils such as gas engine oil can be detected and determined by a small, compact, and low-cost online system that was impossible with the prior art. Further, the deterioration detection method of the present invention is highly reliable, enables continuous deterioration diagnosis of lubricating oil such as gas engine oil used for a gas engine for a cogeneration system (CGS), reduces maintenance, and achieves a CGS system and the like. Can be improved.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a two-wavelength oil deterioration sensor for carrying out a method for detecting lubricating oil deterioration according to the present invention.

FIG. 2 illustrates one embodiment of a decision algorithm that can be used in the present invention.

FIG. 3 divides the degree of deterioration of a used gas engine oil into three patterns of an initial type deterioration (A), an intermediate type deterioration (B), and a late type deterioration (C) from an absorbance at 920 nm and 660 nm by an algorithm. An example is shown below.

FIG. 4 shows an example in which the degree of deterioration (deterioration index) of a gas engine oil in use is output from three calibration curves by an algorithm.

FIG. 5 shows the relationship between the total acid value and the absorbance at 660 nm for the deterioration pattern A of the gas engine oil.

FIG. 6 shows the relationship between the insoluble matter in the deterioration patterns B and C of the gas engine oil and the absorbance at 660 nm.

FIG. 7 is a diagram for explaining the relationship between the absorbance of lubricating oil and the remaining life.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent cell 2 Light emitting part 3 Light receiving part 4 Light source driving part 5 Light quantity detecting part 6 Microcomputer 7 Display device

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenichi Koizumi 3-17-35 Niisonanami, Toda City, Saitama Prefecture Inside Japan Energy Co., Ltd. (72) Inventor Ryutaro Kikutake 2-38 Shinohara Nishimachi, Kohoku-ku, Yokohama-shi, Kanagawa (72) Inventor Tomo Matsumoto 3304-3434, Shiomidai, Isogo-ku, Yokohama City, Kanagawa Prefecture (72) Inventor Katsumi Ikeda 3-3-23, Nishifune, Funabashi City, Chiba Prefecture (72) Inventor Takaaki Ito Sumida, Tokyo 1-47-10 Kyojima-ku, Tokyo Tokyo Gas Sumida Ryo 809 507-2 Toho Gas Co., Ltd. (56) References JP-A-2-236440 (JP, A) JP-A-5-273121 (JP, A) JP-A-4-160349 (JP, JP-A-3-31746 (JP, A) Tokyo Gas Co., Ltd., Toho Gas Co., Ltd., Japan Energy Co., Ltd., "Gas engine oil remaining life evaluation sensor", Japan Energy & Technology intelligence, Japan, Inc. Jetti Co., Ltd., June 26, 1997, June 1997 extra edition, p. 55 (58) Fields investigated (Int. Cl. ⁶ , DB name) G01N 21/00-21/01 G01N 21/17-21 / 61 G01N 33/30 JICST file (JOIS)

Claims (12)

(57) [Claims] 1. A method for measuring the absorbance or the amount of transmitted light at each wavelength of a lubricating oil using two lights of a short wavelength and a long wavelength in a range of 0.4 to 2.5 μm, and lubricating the lubricating oil by a judgment algorithm based on the measured values. Identify the oil deterioration pattern, and then determine the degree of deterioration or remaining life of the lubricating oil from the absorbance or transmitted light of a specific wavelength and the calibration curve of each stored deterioration pattern. Deterioration detection method. 2. The method according to claim 1, wherein a wavelength in the range of 0.45 to 0.7 μm is used for the short wavelength and a wavelength in the range of 0.8 to 1.1 μm is used for the long wavelength. Method. 3. The method according to claim 1, wherein the lubricating oil is a gas engine oil, and the deterioration pattern of the lubricating oil comprises an early type deterioration (A), an intermediate type deterioration (B) and a late type deterioration (C). A method for detecting deterioration of lubricating oil. 4. The position in the figure of the absorbance or the amount of transmitted light of the short wavelength and the long wavelength of the lubricating oil from the xy figure using the absorbance or the amount of transmitted light of both the short wavelength and the long wavelength as the x axis and the y axis, respectively. A method for detecting deterioration of a lubricating oil, comprising: determining a deterioration pattern by using a calibration curve corresponding to the pattern and an absorbance or a transmitted light amount on a shorter wavelength side. 5. The method according to claim 4, wherein a wavelength in the range of 0.45 to 0.7 μm is used for the short wavelength and a wavelength in the range of 0.8 to 1.1 μm is used for the long wavelength. Method. 6. The lubricating oil is a gas engine oil, and the deterioration pattern of the lubricating oil comprises an early type deterioration (A), an intermediate type deterioration (B) and a late type deterioration (C). A method for detecting deterioration of lubricating oil. 7. The absorbance or the amount of transmitted light at each wavelength of the lubricating oil is measured using two lights of a short wavelength and a long wavelength in a range of 0.4 to 2.5 μm, and the lubricating oil is lubricated by a judgment algorithm from the measured values. A method of identifying the deterioration pattern of the oil, and then calculating the remaining life (L) of the lubricating oil based on the following equation from the absorbance or transmitted light amount of a specific wavelength and the calibration curve of each deterioration pattern stored in the memory. To detect deterioration of lubricating oil. Remaining life (L) = {(Q ₁ −Q _X ) / (Q ₁ −Q ₀ )} × 10
0 (%) wherein, Q ₁ is the absorbance or the transmitted light amount of the lubricating oil at the time of the condition to be exchanged, Q ₀ is the absorbance or the transmitted light amount of the lubricating oil at the time of new oil, the absorbance of the lubricating oil at the time the Q _X in Or, on the calibration curve, the remaining life (L ₁ ) when the absorbance or the transmitted light quantity Q ₁ is 0%, and the remaining life (L ₀ ) when the absorbance or the transmitted light quantity Q ₀ is 100%. And 8. The method according to claim 7, wherein a wavelength in the range of 0.45 to 0.7 μm is used for the short wavelength and a wavelength in the range of 0.8 to 1.1 μm is used for the long wavelength. Method. 9. The lubricating oil is a gas engine oil, and the deterioration pattern of the lubricating oil comprises an early type deterioration (A), an intermediate type deterioration (B) and a late type deterioration (C). A method for detecting deterioration of lubricating oil. 10. The lubricating oil is a gas engine oil, and the operating time and / or the integrated power generation of the gas engine and the absorbance of the gas engine oil that fluctuates with time are stored as a data table and obtained by actually detecting deterioration. From the obtained absorbance, based on the data table, the remaining life is calculated by the following equation.
The method for detecting deterioration of lubricating oil according to claim 7, wherein the output is performed as the following. Remaining operation time _{(H) = {(Q 1} -Q X) / (Q X -Q 0)}
× H _X (h) Residual generated power (P) = {(Q ₁ −Q _X ) / (Q _X −Q ₀ )}
× P _X (kWh) where Q ₁ is the absorbance or transmitted light amount of the lubricating oil in the state to be replaced, Q ₀ is the absorbance or transmitted light amount of the lubricating oil at the time of new oil, and Q _X is the lubricating oil at a certain point in time. a of the absorbance or the transmitted light quantity, also, H _X is Sarayu after a running time until when detecting deteriorated, P _X is the Sarayu after power generated until when detecting deteriorated. 11. The method according to claim 10, wherein a wavelength in the range of 0.45 to 0.7 μm is used for the short wavelength and a wavelength in the range of 0.8 to 1.1 μm is used for the long wavelength. Method. 12. The method for detecting deterioration of a lubricating oil according to claim 10, wherein the deterioration pattern of the lubricating oil comprises an early type deterioration (A), an intermediate type deterioration (B) and a late type deterioration (C).