JPS5981421A - Detection of combustion state of fuel in combustion chamber utilizing optical fiber - Google Patents

Abstract

PURPOSE:To enable to detect the combustion state including the flows of fuel and of exhaust gas in a cylinder chamber, which acts as the combustion chamber of a reciprocating internal combustion engine, by a mthod wherein two pairs of optical fibers, which pierce through the partition walls of the combustion chamber, are provided. CONSTITUTION:The light emitted from a light emitting part 1 pierces via a light emitting side optical fiber 2 through a cylinder liner CyL comprising one of cylinder partition walls, keeping enough air-tightness between the exterior and the interior of the liner CyL and propagates from the end 2' of the light emitting side optical fiber 2 to the interior of a cylinder. The end 3' of a light receiving side optical fiber 3, which can receive said light, is provided in the other cylinder partition wall and the light received at said end 3' pierces through the cylinder partition wall, keeping enough air- tightness between the exterior and the interior of the cylinder partition wall and once received, through a light receiving side optical fiber 3, by a light receiving part 4, which detects said light, and then outputted to a frequency analyzer 5 with high analyzing action speed. Said frequency analyzer 5 performs frequency analysis on the levels of the light received.

Description

DETAILED DESCRIPTION OF THE INVENTION There are many unknown details such as fuel flow, ignition timing, flame propagation, and exhaust gas flow. Since these factors have a large impact on combustion efficiency, those involved have conducted intensive research on these factors, and the phenomenon has been elucidated to some extent, but most of these factors have not yet been studied. These are the results of a test using a prototype, and there are still many unknowns about the actual i41'II+. This is because the inside of the 1'ε chamber, where σ] is also burned, has extremely poor environmental conditions in °C due to the presence of high temperature and high pressure gas, which hinders various measurements.

Recently, optical fibers have been used for various data transmission and medical purposes such as visual inspection inside the human body.This optical fiber has excellent high pressure resistance and can withstand a certain degree of high temperature, as well as being able to withstand various external noises. It has excellent properties such as being strong and flexible.

Therefore, if this is installed through the partition wall between the combustion chamber and the outside and transmits the internal situation to the outside, it will not only be possible to clarify the twist angle and phenomena inside the chamber, even if only in part, but also to elucidate the combustion status of the fuel. can be detected. This is because the combustible gas has a high temperature and brightness, so the presence and occurrence of the gas can be easily transmitted to the outside through an optical fiber.

A feature of the present invention is that the combustion state of fuel inside the combustion chamber, etc., which has been difficult to understand in the past, can be detected using an optical fiber.

Various methods can be considered for detecting the combustion status inside the combustion chamber using optical fibers. For example, if only the generation of combustion gas is to be detected, since the gas itself is an object with a degree of To find out, frequency analysis can be performed.

However, when investigating the flow state of fuel before ignition or gas after combustion, it is essential to provide some kind of lighting inside the combustion chamber. Is this invention something like this? The purpose of this research is to detect the combustion situation, including the flow of fuel and exhaust gas, in the cylinder chamber, which is the combustion chamber of the reciprocating internal combustion engine μ'j, whose phenomena elucidation is particularly important for Tazabe F. It is something.

Embodiments of the present invention will be described in detail below with reference to the drawings. Figure 1 shows the fj of the cylinder head when the present invention is implemented in a reciprocating internal combustion engine (hereinafter referred to as engine μm11).
&m is a control block diagram including a conceptual diagram, and shows a cylinder chamber (hereinafter referred to as a cylinder) which is a combustion chamber.
is isolated from the outside by partition walls such as the cylinder head OH, piston P1, and cylinder liner OyL, and the inside is compressed and
The explosion and exhaust culms are filled with hot or pressurized gas.

The light from this cylinder (a well-known light emitting unit/which is a light beam that propagates through the cylinder (3y''-), which is a highly transparent ring such as a laser beam, is transmitted through the light emitting side optical fiber to the cylinder liner, which is one of the ring partition walls. It penetrates the OyL while maintaining sufficient airtightness, and transmits the light from the end of the light-emitting side optical fiber to the inside of the cylinder.
1i11 base] Installed at the end J of the cylinder or another partition wall of the cylinder (in the first part, it is provided on the cylinder liner OyL as shown in the figure, but of course it is not limited to this position), and the current end The light received by the part is first received by a known light receiving part that detects the light through the light receiving side optical fiber 3 by closing the cylinder partition wall while maintaining airtightness from the outside. The frequency component J:li of which the analysis operation speed is high is output to the li device S. Ori r for dazzling frequency
It is assumed that the device S performs frequency analysis on the received light level using a known method.

The known curve showing the frequency characteristics of the output destination of the light emitting section l is as shown in Fig. 2, and the deviation is as follows.
When there is no fuel, flame, exhaust gas, etc. inside the cylinder, the frequency characteristics of the light detected by the light receiver 4 are almost the same as those shown in FIG. 1. Of course, even if the combustion engine is not being used, there will still be water vapor and dust in the atmosphere, light transmission Q': r IJ+, and 414 on the way.
It is slightly different from this due to the influence of arrows, for example, the force that can cause a slam (which is also written in Fig. It is possible to take countermeasures by knowing the detection level of the slam.

In such a situation, if there are fuel particles, exhaust gas, etc. inside the cylinder, the level of light detected by the receiver will be lower than that shown in the 21st knee 21, and will reach the slam level as shown in Figure 3. The inside of the cylinder was roughly burnt'1
．． When the detection level becomes 15, as shown in Fig. tI, the detection level of ζ and the 1st bang shape in a specific band is different from the 1st bang shape detection level shown in Fig. It is possible that the detection level increases from the moment, but if such a bang is detected, the trace will be nothing but the presence of an extremely strong flame inside the cylinder. Alternatively, by comparing the pattern shown in FIG. 1 with the pattern shown in FIG.
Calibrate the detection level using a model etc. in advance and adjust the detection level accordingly.
Take measures such as increasing the number of ill fixed points! i 1-
This allows you to learn more about the conditions inside the cylinder, such as the size of the flame, temperature distribution, and even i! -1i By performing continuous measurements, it is possible to understand the phenomena that lead to fuel ignition.

In the main fruit, il, i 1"y'lJ, objects without bright spots inside the cylinder, i.e., the flow situation of the heating material, Jl after combustion, gas, etc. We have described the method of detecting the light of the i) 1; in the cylinder to detect the 2J arcuate) 44 or the burnt 1'.

7Ai4, that is, if only the flame generation situation is to be investigated, it goes without saying that the light emitting part l shown in 31H and the optical fibers 2 and l connected thereto are too small. The pattern of the shape L-1: to be detected includes the pattern a13 as shown in the figure. '1''
7'j: Since the straw is not burnt and sometimes there is no Le II point in the cylinder, the level is θ in the whole band.
When ignition occurs, the levels of various bands increase depending on the flame generation situation.

Regarding the situation of combustion detection, we have described an example in which frequency analysis at the detection level is performed to understand the situation such as flame size and temperature distribution, but this is only one example, and such detailed detection is not possible. is not necessary, for example, the presence or absence of flame,
If only the intensity or temperature is to be detected, the output from the light receiving section is input to the well-known output converter shown in Figure S and converted into ↑■1. It is also possible to convert it into energy output, further amplify it using a known amplifier 7, detect it at a certain lightning level, and judge the state of the lightning from that situation.As for the means for outputting the detection level, Various other implementation methods are possible. Furthermore, the embodiment shown in Fig. 1 describes a method for detecting the combustion situation inside the cylinder, which is the combustion chamber of a reciprocating engine, where it is extremely difficult to grasp the situation. The method for detecting the combustion state of the fuel in ) 5[' can also be implemented in the same manner as described above.

[Brief explanation of the drawing]

FIG. 1 is a control block diagram including a conceptual diagram of the structure around the engine cylinder when the present invention is implemented in a reciprocating internal combustion engine. Figures 2 to 3 show an example of the detection level when frequency analysis is performed on light from inside the cylinder received at the end of the optical fiber, and Figure S shows another embodiment of the present invention. FIG. Oy...Cylinder inside, CH...Cylinder head,
'; P ii... Piston, OyL -... Cylinder liner, l... Light emitting part, Y... Light emitting side optical fiber,
λ′...End of light-emitting side optical fiber, 3... Light-receiving side optical fiber,! ... Light-receiving side optical fiber end, t... Light-receiving section, left... Frequency phase splitter, 6... Electrical output converter,
7... Increased width 11 Kikakuba Taishu $2 ward

Claims (1)

[Claims] In order to detect the combustion status inside the combustion chamber, a pair of optical fibers are installed that pass through the partition wall of the combustion chamber. The light is propagated from the end to the inside of the combustion chamber, and one end of the other l pairs of optical fibers inside the combustion chamber is installed at a position where the light propagated by the optical fiber can be received.
By detecting the level of light captured at this end at the other end outside the combustion chamber, the state of combustion of the fuel inside the combustion chamber can be detected outside the combustion chamber. A method for detecting the combustion status of fuel inside a combustion chamber.