JPH03251612A - Abnormality detecting device for burner - Google Patents

Abstract

PURPOSE:To enable detection of abnormal combustion occurring due to a break in an air-fuel ratio by a method wherein, in an abnormality detecting device for a burner for a hot water feeder, a flame rod is protruded from the opposite side to the burner of a combustion chamber toward the burner, and the presence of abnormality is discriminated by means of a detecting signal from the flame rod. CONSTITUTION:A flame rod 14 is protruded from the lower end of a combustion chamber 5 toward a fire hole 8A of a burner 8, and a protruding end 14A thereof is positioned in the position of flame F during normal combustion. The flame current of the flame rod 14 is inputted to a microcomputer, combustion is stopped when a flame current is reduced to a value lower than a specified value, and an abnormality indicator lamp is lighted ON. This constitution enables detection of abnormal combustion due to a break in an air-fuel ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to an abnormality detection device for combustion machines such as hot water boilers, water heaters, and space heaters.

(b) Conventional technology In this type of combustion machine, for example,
As disclosed in the publication, a flame rod is provided near the burner, and the presence or absence of a flame can be detected by determining the flame current level of the flame rod.

(c) Problems to be Solved by the Invention In the above-mentioned combustion machine, regardless of the length of the flame, flame current flows as long as there is a flame, so the air-fuel ratio may collapse for some reason and the flame may extend. Even if it did shrink, it was difficult to determine whether there was an abnormality or not. As a result, abnormal combustion continues, causing problems such as damage to the combustion chamber due to local overheating and the tendency to generate soot and carbon monoxide.

This invention was made in view of the above facts,
The purpose is to detect abnormal combustion caused by a change in the air-fuel ratio.

(d) Means for Solving the Problems In this invention, in a combustion machine having a combustion chamber facing a burner at one end, a frame rod protrudes from the other end of the combustion chamber toward the burner; This configuration includes means for determining whether or not there is an abnormality based on the detection signal.

(*) If the exhaust chimney or air supply port is completely closed, if too much fuel is supplied due to an electromagnetic pump failure, or if there is insufficient combustion air due to a burner motor malfunction, the combustion speed will be slower than normal. , the flame inside the combustion chamber becomes longer. Conversely, if there is too little fuel compared to the combustion air, the combustion speed will be faster than normal and the flame will be shorter. Therefore, by making the flame rod protrude toward the burner from the other end of the combustion chamber, the detection signal of the flame rod changes depending on the length of the flame, and can be used to determine the presence or absence of an abnormality.

(f) Example Hereinafter, embodiments of the present invention shown in the drawings will be described.

FIG. 1 shows a hot water boiler (combustor) to which this invention is applied. In Figure 1, (1) is an outer case;
(2) is an ice chamber formed by joining the bottomed inner shell (3) and outer shell (4) at the top, (5) is a combustion chamber completely formed inside the ice chamber, and (6) is a combustion chamber. (5) Refractory material covering the upper part, (
7) is a heat insulating material provided around the outer periphery of the water chamber (2); (8) is a burner that penetrates the fireproof material (6) and has its combustion port (8A) facing the upper space of the combustion chamber (5); 9) connects the fireproof material (6) to the combustion chamber (5) so as to surround the combustion port (8A) of the burner (8).
a baffle cylinder (10) that is suspended to an intermediate height position and has a large number of baffle pieces (9A) on its outer peripheral wall;
(11) is an exhaust muffler that penetrates the refractory material (6) and communicates with the upper space of the combustion chamber (5); (11> and (12)) are a water inlet and a hot water inlet that communicate with the water chamber (2), respectively; (13) connects the bottom of the inner shell (3) and the bottom of the outer shell (4), and
) The cylindrical stay (14) is attached to the stay (13) to support the load of the outer shell (4), and the stay (14) is attached to the stay (13) and
) is a frame rod that protrudes from the lower end of the burner (8) toward the firing port (8A), and the frame rod (14)
The protruding end (14A>) is in a position in contact with the flame (F) when combustion in the burner (8) is normally performed.

For example, as shown in FIG. 2, this frame rod (14) has a piece (15) attached to the insulator part (14B) of the frame rod (14), and the piece (15) is attached to the stay (15).
13) to the threaded support rod (16) with a nut (17), or attach the frame rod (14) to the threaded support rod (16) as shown in Figure 3.
) is installed by threading the insulator part (14B) of the cylinder (14B).
8), and this installation is done by directly attaching the tube (18) to the stay (13).
) is installed by screwing it on.

FIG. 4 shows a control device for the hot water boiler described above. In Fig. 4, (19) is a microcomputer, and the input side of the microcomputer includes an operation switch (20), a water temperature setting device (21), and a water temperature that detects the water temperature in the water chamber (2). Sensor (22) and frame rod (
14), and an electromagnetic pump (14) for supplying fuel to the burner (8) is provided on the output side of the microcomputer (19).
23), a burner motor (24) that supplies combustion air to the burner (8), and an abnormality indicator lamp (25).

This microcomputer (19) is connected to the operation switch (2).
0) is turned on, the temperature completely set by the hot water temperature setting device (21) and the hot water temperature detected by the hot water temperature sensor (22) are compared, and if the hot water temperature is lower than the set temperature! The magnetic pump (23) and burner motor (24) are allowed to operate, causing combustion to occur in the burner (8).

Also, the frame tiI of the frame rod (14) is the fifth
As shown in the figure and FIG. 6, when the temperature drops below IL, combustion is stopped and an abnormality indicator lamp (25) is turned on, which also serves as a discrimination means of the abnormality detection device.

When combustion occurs in the burner (8), the combustion gas flows into the combustion chamber (
The lower part of 5) is reversed and the water chamber (2) is moved up the combustion gas passage (26) between the inner shell (3) and the baffle tube (9).
exchange heat with water. The exhaust gas that has undergone heat exchange is muffled by an exhaust muffler (10), and then is emitted into the atmosphere through an exhaust chimney (not shown). Further, hot water in the ice room (2) is sent to the usage area from the hot water supply port (12) at any time, and new water is replenished from the water supply port (11) to the ice room (2) at the same time as hot water is supplied.

During the above-mentioned hot water supply operation, when the combustion air becomes insufficient compared to the fuel and the combustion speed becomes slower than normal, the flame (F)
The frame rod (14) (7) 7 frame tf (1 is work) is moved to the position shown below. Therefore, the microcomputer (19) stops combustion in the burner (8) and turns on the abnormality indicator lamp. (25) is allowed to light up to notify an abnormality.

Conversely, when the fuel is insufficient compared to the combustion air and the combustion speed becomes faster than normal, the flame (F) moves to the position F2 and becomes shorter. In this case as well, since the flame current I becomes less than It, the microcomputer (19)
), and the abnormality indicator lamp (25) is turned on. The same applies if the fire is extinguished for some reason during combustion.

FIG. 7 shows another embodiment of the invention. In this embodiment, the flame rod (14) is made shorter than the one in Fig. 1, and its protruding end (14A) is connected to the normal flame (F).
It is located lower. In this case, when the flame (F) becomes longer than normal and the current in the flame rod (14) exceeds a predetermined value, combustion is stopped so that the abnormality can be notified.

(g) Effects of the invention Since this invention is configured as described above, even if the air-fuel ratio collapses and the length of the flame changes due to closure of the supply/exhaust passage, malfunction of the fuel pump or blower, etc. It is ideal as a safety device to prevent local heating of the combustion chamber and the generation of large amounts of soot and nitric oxide.

[Brief explanation of drawings]

The figures relate to an embodiment in which the combustion machine abnormality detection device of the present invention is applied to a hot water boiler, in which Figure 1 is a cross-sectional view of the hot water boiler, Figure 2 is a perspective view showing an example of frame rod installation, and Figure 2 is a perspective view showing an example of frame rod installation. Figure 3 is a perspective view showing another example, Figure 4 is a block diagram of a hot water boiler control device, Figure 5 is an explanatory diagram showing the relationship between flame length and flame current, and Figure 6 is a microcomputer. FIG. 7 is a sectional view showing another example of the hot water boiler. (5)...fig room, (8)...burner, (14)
... Frame rod, (19) ... Microcomputer (discrimination means).

Claims (1)

[Claims] (1) In a combustion machine that has a combustion chamber with a burner facing one end, a flame rod protrudes from the other end of the combustion chamber toward the burner, and the presence or absence of an abnormality is determined based on the detection signal of this flame rod. An abnormality detection device for a combustion machine, characterized by comprising means.