JPH05231642A - Method and apparatus for detecting choking of burner tip nozzle - Google Patents

Abstract

PURPOSE:To prevent danger based on the misfiring of a burner by analyzing the choking of a burner tip nozzle according to the variation with time of the soot luminous characteristics and/or light-absorption characteristics of steam by a spectroscopic analysis device for a plurality of visual fields. CONSTITUTION:Liquid fuel flames 10 which are jetted from a burner tip nozzle are received by an optical probe 1 with a plurality of visual fields, and transmitted to a spectroscopic analysis device 4 by a relay optical fiber 2 and channel selector 3. Then, the choking of the burner tip is detected according to the variation with time of the soot luminous characteristics and/or light-absorption characteristics of steam to respective visual fields by a data analysis device 5 by signals from the spectroscopic analysis device 4. By this method, since the choking of the burner tip nozzle can be detected at an early stage, the danger which may lead to the explosion of a combustion furnace based on the misfire of a burner can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner tip nozzle clogging condition detection device and method, and more particularly to a device and method for detecting the clogging condition of an oil burning burner tip nozzle based on flame emission spectrum analysis. ..

[0002]

2. Description of the Related Art In a burner for burning oil such as heavy oil, the burner tip nozzle is clogged. This is a phenomenon that occurs when part of the fuel is thermally decomposed to generate solid carbon content by receiving heat from the flame and the solid carbon content is fixed to the inner surface of the nozzle of the burner tip. The clogging of the burner tip is not completely prevented by the current technology.

Therefore, conventionally, when the flame is observed from the viewing window of the burner mounting surface and a reduced flame showing a decrease in the fuel flow rate is observed or an unstable combustion state is observed, the combustion is stopped. Then, the burner tip was removed to remove the solid carbon content of the blockage. Sometimes I replaced it with a spare burner tip. With this conventional technique,
There is a problem that it can not be judged unless the burner tip nozzle is clogged considerably. Therefore, when such a combustion state occurs, measures such as cleaning the burner tip nozzle relatively quickly from a safe driving perspective. Was needed.
As a safety measure, if the burner tip is clogged, the flame detector will output a misfire signal even if there is a misfire or there is a risk of explosion in the combustion furnace. Therefore, when clogging of the burner tip nozzle became apparent, the burner tip was cleaned or replaced with a new one relatively quickly.

[0004]

That is, the above-mentioned prior art has a problem that it cannot be judged unless the burner tip nozzle is in a considerably advanced state. An object of the present invention is to provide a burner tip nozzle blockage detection device and a detection method capable of detecting blockage of a burner tip nozzle in an early blockage state.

[0005]

In order to achieve the above object, the first invention of the present application is to provide a light receiving device for receiving flame light of liquid fuel injected from a burner tip nozzle, and transferring flame light from the light receiving device. Device, a spectroscopic analysis device that spectrally analyzes the transferred flame light, and a data processing device that performs analysis processing based on the output signal of the spectroscopic analysis device, and the light receiving device receives light in a plurality of fields of view. The present invention relates to a burner tip nozzle clogging detection device configured to analyze the clogging state of the burner tip nozzle from the change with time of the soot emission characteristic and / or water vapor absorption characteristic of the spectroscopic analysis device for each visual field.

A second invention of the present application is a light receiving device for receiving the flame light of liquid fuel injected from a burner tip nozzle, a device for transferring the flame light from the light receiving device, and a spectrum analysis of the transferred flame light. And a data processing device that performs analysis processing based on the output signal of the spectroscopic analysis device, wherein the light receiving device is configured to receive light in a plurality of visual fields, and the soot by the spectroscopic analysis device for each visual field is provided. Blockage of the burner tip nozzle characterized by being configured to analyze the clogging state of the burner tip nozzle from the relative relationship of the soot emission characteristic and / or the water vapor absorption characteristic between the respective visual fields based on the light emission characteristic and the water vapor absorption characteristic Regarding a detection device.

According to a third aspect of the present invention, the flame light of the liquid fuel injected from the burner tip nozzle is received by a light receiving device in a plurality of fields of view, the received light is transferred by a transfer device, and the transferred flame light is analyzed by a spectrum. The burner tip nozzle blockage detection method, in which the data processing device analyzes the presence or absence of blockage of the burner tip nozzle based on this analysis result, in the soot emission characteristics and water vapor absorption characteristics of the spectroscopic analyzer, the fuel flow rate in each field of view. (C) Calculate the value,
The present invention relates to a method for detecting blockage of a burner tip nozzle, characterized by analyzing a blockage state of a burner tip nozzle from the relative relationship between the calculated value and / or the calculated value between respective visual fields.

[0008]

[Function] The solid carbon content adheres to the burner tip nozzle
It is not generated uniformly in the circumferential direction of the nozzle. For this reason, the oil fuel that was initially uniformly sprayed becomes non-uniformly sprayed as the solid carbon content is fixed. 1
When one flame is monitored from a plurality of fields of view, the relationship of the flame emission spectrum intensity characteristics between the fields of view before the solid carbon content is fixed, at the initial stage of the solidification, and at the final stage is different. Therefore, by monitoring the change in the relative relationship of the flame emission spectrum intensity between the respective visual fields, the change in the spray state can be known, and the blockage state of the burner tip nozzle can be known at an early stage.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of an apparatus adopting the burner tip nozzle blockage detecting method of the present invention. This device includes a plurality of optical probes 1, a plurality of relay optical fibers 2, an optical channel selector 3, a spectroscopic analysis device 4, and a data analysis device 5.
It is mainly composed of The optical probe 1 has a plurality of fields of view.

As a result, the light from the flame 10 is received by each optical probe 1 and transferred to the optical channel selector 3 through the relay optical fiber 2. The optical channel selector 3 selects the relay optical fiber 2 to be analyzed,
The flame light transferred by the relay optical fiber 2 is spectrally analyzed by the spectroscopic analyzer 4. The data analysis device 5 clearly indicates the burner tip nozzle blockage state at this time based on the spectrum analysis result.

FIG. 2 shows an example of how the optical probe is attached. The optical probe has a 5 ° inclination to the burner axis,
It was mounted so that the optical probe axis and the burner axis intersected at about 1.5 m from the combustion furnace wall. This optical probe has 3
Each field of view has 0 °, 15 ° with respect to the optical probe axis on the plane of the optical probe axis and the burner axis.
It has an inclination of 30 degrees.

FIG. 3 shows an example of an emission spectrum of an oil burning flame. Small optical transmission loss of repeater optical fiber 0.4
In the wavelength range of up to 1.6 μm, an emission spectrum of soot can be seen on the longer wavelength side than 0.7 μm, and the spectrum intensity due to absorption of water vapor (1.4
μm) is observed. The flame temperature can be known from the emission characteristics of soot by using the relationship of Prandtl's radiation law. Usually, flame temperature is measured using spectral characteristics in the wavelength range of 0.8 to 1.0 μm. When a high-temperature flame is formed, the slope value of the spectrum intensity in the wavelength range of 0.8 to 1.0 μm becomes large (this 0.8 to 1.
The slope value of the spectral intensity in the 0 μm wavelength region is called soot luminescence).

Absorption of water vapor is a phenomenon caused by the flow of water vapor between the flame and the optical probe. The amount of decrease in the spectrum intensity increases as the water vapor concentration and flow rate increase. By utilizing this phenomenon, it is possible to know the change in the air flow rate, the recirculation exhaust gas flow rate, or the swirling force of the mixed gas of the combustion air and the recirculation exhaust gas (the amount of decrease in the spectrum intensity is referred to as water vapor absorbance).

It is known from a publicly known example (JP-A-3-502252) that both the soot luminescence and the water vapor absorbance decrease when the fuel flow rate decreases.
4, 5 and 6 show, as one of the measurement examples, the field of view of the optical probe 0 °, 15 when using a new burner tip without blockage, burner tip in the initial blockage state and burner tip in the final blockage state. The average values of soot luminescence and water vapor absorbance at ° and 30 ° are shown. In the case of the unblocked burner tip shown in FIG. 4, the magnitudes of soot luminescence and water vapor absorbance are in the order of 0 °, 15 °, and 30 ° fields of view. As the occlusion progresses, the magnitudes of soot luminescence and water vapor absorbance are both 15 °, 0 °, 30 °
In the order of °, the field of view was further changed in the order of 15 °, 30 °, and 0 °, which changed.

From this measurement result, the field of view of the optical probe was 0.
It can be seen that the flow rate of the fuel sprayed in the ° direction was reduced most, and that the solid carbon content was fixed to the fuel flow path side in the burner tip nozzle sprayed in the direction of 0 ° of the visual field. Another embodiment of the present invention is a non-averaged measurement of soot luminescence and water vapor absorbance and their relationship,
It is used for a detection signal of blockage of the burner tip nozzle. In the examples of the present invention described above, in order to obtain the average value of the soot luminescence and the water vapor absorbance, there was a problem that a lot of time was spent for measurement due to the influence of flame fluctuation and mutual interference of flames. According to the present embodiment, an effect that the measurement time can be greatly shortened can be obtained.

The soot luminosity a and the water vapor absorbance b are approximately inversely proportional to each other by the following equation. And
There is a relation that the value of C increases as the combustion increases.

[0017]

## EQU1 ## a.b = C (constant) (1) For each field of view of the optical probe, the C value is calculated from the soot emission rate a and the water vapor absorbance b of the flame emission spectrum to be measured. This calculated value C is an approximate value of the fuel flow rate.

This method of knowing the fuel flow rate is applied to the method of the above-mentioned embodiment. That is, the relative relationship between the C values of the respective visual fields and the C values of the respective visual fields is obtained, and if the C value decreases or the relative relationship of the C values between the visual fields changes, the burner tip nozzle is clogged. To do. FIGS. 7 and 8 show the soot luminescence a, water vapor absorbance b and C value of the burner chip without blockage and the burner chip in the final blockage state, respectively. FIG. 7 corresponds to FIG. 4 described above, and FIG. 8 corresponds to FIG. 6 described above.

It is also possible to detect the "reduced flame showing a decrease in fuel flow rate" and the "unstable combustion state", which is the conventional method of detecting the blockage of the burner tip nozzle, by flame emission spectrum analysis. Specifically, soot luminescence and water vapor absorbance are detected over time, soot luminescence and water vapor absorbance decrease indicating a decrease in fuel flow rate,
If changes in soot luminescence and water vapor absorbance are observed over time, it is considered that the burner tip nozzle has been considerably blocked.

[0020]

According to the present invention, burner tip nozzle blockage can be detected at an early stage, and if the burner tip is cleaned at this stage, there will be no misfire or misfire signal output from the flame detector, which will cause an explosion in the combustion furnace. You can eliminate the risk of connection.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a combustion diagnosis system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a mounting state of an optical probe.

FIG. 3 is a diagram showing an example of an emission spectrum of an oil burning flame.

[Fig. 4]

[FIG. 5]

FIGS. 4, 5, and 6 are measured values (average values) of soot luminescence and water vapor absorbance when using a burner chip without blockage, a burner chip in an initial blockage state, and a burner chip in a final blockage state. It is a figure which shows an example.

[FIG. 7]

FIG. 7 and FIG. 8 are views showing an example of measured values of soot luminescence and water vapor absorbance when using a burner chip without blockage and a burner chip in an end stage blockage, respectively.

[Explanation of symbols]

1 ... Optical probe, 2 ... Relay optical fiber, 3 ... Optical channel selector, 4 ... Spectroscopic analyzer, 5 ... Data analyzer,
6 ... combustion furnace wall, 7 ... burner, 8 ... swirl blade, 10 ... flame,
11 ... Fuel, 12 ... Air, 13 ... Recirculated exhaust gas.

Claims (3)

[Claims] 1. A light receiving device for receiving flame light of liquid fuel injected from a burner tip nozzle, a device for transferring flame light from the light receiving device, and a spectroscopic analysis device for spectrally analyzing the transferred flame light, The light receiving device has a data processing device for performing analysis processing based on the output signal of the spectroscopic analysis device, and the light receiving device is configured to receive light in a plurality of visual fields, and soot emission characteristics and / or water vapor absorption by the spectroscopic analysis device for each visual field. A burner tip nozzle clogging detection device configured to analyze the clogging state of a burner tip nozzle from changes in characteristics over time. 2. A light receiving device for receiving the flame light of liquid fuel injected from a burner tip nozzle, a device for transferring the flame light from the light receiving device, and a spectroscopic analysis device for spectrally analyzing the transferred flame light. It has a data processing device that performs analysis processing based on the output signal of this spectroscopic analysis device, and the light receiving device is configured to receive light in a plurality of visual fields, soot emission characteristics by the spectroscopic analysis device for each visual field, water vapor absorption characteristics A burner tip nozzle blockage detection device configured to analyze the blockage state of the burner tip nozzle based on the relative relationship of soot emission characteristics and / or water vapor absorption characteristics between the respective visual fields. 3. The flame light of the liquid fuel ejected from the burner tip nozzle is received by a light receiving device in a plurality of fields of view, the received light is transferred by a transfer device, and the transferred flame light is analyzed by a spectroscopic analysis device. In a burner tip nozzle clogging detection method in which a data processing device is used to analyze the presence or absence of clogging of the burner tip nozzle based on the analysis results, the fuel flow rate (C) value in each visual field is calculated from the soot emission characteristics and water vapor absorption characteristics of the spectroscopic analysis device This calculated value and /
Alternatively, the blockage detection method of the burner tip nozzle is characterized by analyzing the blockage state of the burner tip nozzle from the relative relationship of the calculated values between the respective visual fields.