JPS60202230A - Combustion device - Google Patents

Abstract

PURPOSE:To perform high precise detection of a combustion condition by a method wherein sensors, detecting a combustion condition, are respectively located to both ends of the burner port of a line burner, and a control means, which detects a combustion condition through comparison of sensor outputs therfrom with each other, is provided. CONSTITUTION:Sensors 7 and 8 are located to the both ends of a total primary line burner, and various combustion conditions are detected by means of outputs from the two sensors. Fuel, for example, LPG, having high gas specific gravity, forms flame distribution like a flow alpha with a main flow flowing on the bottom of a baurner body 2 since a specific gravity after incoming of the air is increased over 1 of the air, gas specific gravity of LPG is about 1.6, and concentration distribution also tends to become alpha. Conversely, the specific gravity of gas such as methane is 0.5-0.6, and since gas body is apt to flow to the upper surface side of a burner body, concentration distribution is apt to form the shape of beta. Thus, when either the two sensors attains a threshold, a fuel velve 10 is closed to stop the supply of fuel to ensure safety. Detection of either sensor outputs at opposite ends of a bruner enables detection of safe rise and an oxygen deficiency condition before either of burthers is brought to poor combustion condition.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a line-shaped post-combustion device.

Conventional structure and its problems Traditionally, detection devices for this type of primary combustion device include thermocouples, flame rods, and various 02 sensors.Recently, detection items such as ignition, combustion status, oxygen deficiency, backfire, etc. have been used. As the number of burners increases, higher safety is required, and the detection of combinations of multiple hinges is also increasing. (If the fuel ratio is less than 1.0, combustion will be incomplete.) If the regulation conditions are exceeded, there will be problems such as excessive CO generation and failure to ignite with full heat. It is difficult from a design standpoint to make the air-fuel ratio and flame length uniform in both directions. The flame formed on the full flame hole 1 in Figure 1 tends to have a different flame length depending on the amount of combustion or the type of fuel gas, as shown by the solid line 1-α and the dotted line β. The reality is that it is difficult to obtain a suitable detection letter 1g'.

Purpose of the Invention The present invention is to detect combustion conditions with high precision. Purpose and 1-ru.

Structure of the Invention In order to achieve this object, sensors for detecting the combustion state are provided at both ends of the flame hole of the line-shaped burner, and by comparing the sensor outputs, it is possible to determine whether the combustion state is F? It is equipped with a control means for detecting the

With this configuration, even if there is a distribution of flame length or sudden air/fuel mixture at both ends of the flame hole, the entire combustion state can be detected by comparing the outputs of both sensors, and the fuel can be controlled appropriately. It has the effect of being able to do something.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1st
In the figure, a primary air hole 3 is provided at the right end of the burner body 2 below a full-length flame hole 1 which is rib-shaped and made of wire mesh. In addition, a throttle part 4 is provided in this part, and a leveling plate 5 is provided below the right end of the flame hole 1 to ensure a uniform mixture of air 4 and fuel.A combustion chamber 6 is provided in the upper part of the flame hole 1. A flame rod 7 is installed at the top of the left flame hole 1 and a tin oxide 8 is installed at the top of the right flame hole 1 as a sensor by penetrating the insulation of the combustion chamber wall, and the sensor output is calculated and judged by the control device 9. , fuel valve 10
Meetings are open and closed. Is 11 the fuel supply nozzle? show. In the above configuration, the burner body 2 is designed so that the equalizing plate 5 uniformly mixes the fuel supplied from the nozzle 11 and the air sucked from the secondary blow hole 3 and uniformly distributes it to the flame hole 1. However, when considering gas as a fuel, the specific gravity is 0.
．． There is wide variation from city gas at 5.0 to butane at 2.1, and if the aperture width of the fuel is widened, it is extremely difficult to achieve truly uniform distribution and uniform concentration distribution. The flame distributions of curves a and β on flame hole 1 in FIG. 1 may be completely opposite. For example, gases with high specific gravity such as LPG,
Since the specific gravity of the total air flow is still much higher than that of air (1), it flows as the entire main stream at the bottom of the burner body 2, and the flame distribution is like α, and the gas specific gravity of LPG is around 1.6, so the concentration distribution is also like α. It tends to become. Conversely, the specific gravity of a gas such as methane is 0.5 to 0.6, and the gas tends to flow toward the upper surface of the burner body, so the concentration distribution tends to be in the shape of β.

these? I try to equalize it with the equalizing plate 5, but what about the aperture ratio when the gas type is LPG? As the size increases, the distribution changes like a curve from a to β. Therefore, it is difficult to achieve uniform concentration and flame distribution with a linear burner of the same shape across all types of fuel and expansion of throttle width. It's also very difficult. Figure 2 shows the sensor output at the rise. The solid line ■@ is the characteristic when the flame and concentration distribution is α, and the dotted line ■＠ is the characteristic when the flame and concentration distribution is β. In order to detect the rise, the rise of the ion current in (■) is early depending on the concentration and flame distribution, and reaches the threshold value A of the flame current at (t, sec) as shown in the figure. In the tin oxide sensor section on the right end where the flame distribution is low, the flame temperature rises slowly as shown by @.
Since the flame height is low, air flows in from the upper part of the combustion chamber 6, and since the tin oxide 8 does not enter the flame zone, the resistance value gradually decreases.

Therefore, until the threshold value B is reached, it is much slower than t4 S e C and t of the ion current. Therefore, for ignition detection, it is sufficient to determine whichever is earlier of the threshold values of the ion current (■) and the sensor resistance O. On the other hand, in the case of the flame and concentration distribution of β, as shown in the figure, the change in sensor resistance becomes steeper, and it takes t2 seconds to detect the threshold value B, whereas the ion current slows down to t s se C. Therefore, ignition detection in this case may be performed using a sensor resistance. Furthermore, as shown in FIG. 3, changes in the resistance value of tin oxide 8 (Sn02) and changes in the current value of the frame rod 7 due to oxygen deficiency are shown. The θO curve shows the characteristics when α is flame and concentration distribution, and the θ0 curve β shows all the characteristics when distributed. When the distribution is a, the atmosphere of 5n028 has a high 02 concentration from the beginning, so the concentration decreases due to oxygen deficiency and 0.
KiO% is at the 17' position, but in the case of β distribution, on the contrary, the atmosphere is 0. Since the concentration is within the flame zone from the beginning, it is low, as shown in the figure, at about <18.5%, the current of o22O27 is oxidized. The properties are opposite to those of tin (SnO) 8.

The resistance value changes suddenly. Frame rod R in the diagram,
E is the resistance value of tin oxide (Sn○)8.
2.

Threshold value indicates the threshold value of the ion current value of frame rod 7. Therefore, if the threshold value of either sensor is reached, the fuel valve 10? By detecting sensor output from either end of the burner, such as stopping closed combustion and maintaining safety, it is effective to safely detect start-up or oxygen deficient sound before either burner starts to suffer from poor combustion. It goes without saying that the sensors may be two 0.2mm sensors or any other type of sensor, or that the control means for the detection method may be changed.

Effects of the Invention As described above, the combustion apparatus of the present invention provides the following effects.

(1) Sensors are provided at both ends of the primary line burner, and various combustion state sounds are detected using the outputs of both sensors, so that appropriate control means can be taken while constantly determining the combustion state of the burner as a whole.

(2) In a full-order line burner with poor distribution, by providing sensors at both ends, combustion state starvation can be appropriately detected even if the aperture ratio is set large.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a characteristic diagram of changes in sensor output over time, and FIG. 3 is a characteristic diagram of changes in sensor output during oxygen deficiency. 1..."・Flame hole, 7...Frame rod, 8.
...Tin oxide, 9...Control device. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 21, 3rd N

Claims (1)

[Claims] (1) A combustion device that includes sensors for detecting all flame conditions at both ends of the flame hole of a line-shaped burner, and a control means that compares the outputs of the sensors to detect the combustion condition. (Takumi) The combustion device according to claim 1, wherein one of the sensors is a flame rod, and the other is an 02 sensor made of zirconia oxide, tin oxide, or the like.