JPH03260513A - Mixing ratio controller for burner - Google Patents

Abstract

PURPOSE:To provide a compact and less-expensive mixing ratio control device for a burner capable of preventing any erroneous sensing caused by a dew formation by a method wherein means for sensing a mixing ratio between gas and air is constructed such that a bypath for communicating a gas supplying passage with an air supplying passage is provided with an air speed sensor. CONSTITUTION:In a mixing ratio control device for a burner, a bypath B1 for communicating a gas supplying passage G1 with an air supplying passage A1 is provided, wherein its bypath B1 is provided with an air speed sensor 10. When a pressure difference occurs between the gas supplying passage and the air supplying passage, air having an air speed corresponding to the pressure difference is generated in the bypath. Accordingly, sensing of its air direction and air speed enables the pressure difference to be detected by sensing them with an air speed sensor. Since the bypath is used for communicating both supplying passages, a dew formation is hardly generated and even if the dew formation occurs, it may be removed by an air purging or the like.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a mixing section for supplying a mixture of combustion gas and air to a burner, and a gas amount adjusting means for supplying gas to the mixing section. an air supply path including an air supply means for supplying air to the mixing section; a target setting means for setting a target mixing ratio of gas and air in the mixing section; and a gas supply path in the mixing section. a detection means for detecting a mixture ratio of gas and air; and a detection means for controlling the gas amount adjustment means or the air adjustment means so that the mixture ratio of gas and air in the mixing section becomes a target mixture ratio based on the detection information of the detection means. The present invention relates to a mixture ratio control device for a burner, which is provided with a control means for controlling the burner.

[Conventional technology]

In the mixture ratio control device for a burner as described above, it is desirable that effective combustion can be stably maintained even when the combustion amount adjustment range is widened. On the other hand, it is desirable that the device be compact and inexpensive.

Conventionally, it has been difficult to meet the above requirements with the pressure equalizing valve system used for boat fishing.

Therefore, as a means to meet the above requirements, for example,
There is one proposed in Japanese Patent Publication No. 64-9525.

That is, as shown in FIG. ) The amount of gas or air is adjusted based on the detected state of the air.

By the way, the differential pressure sensor (30) is configured to detect differential pressure by detecting, for example, elastic deformation of a diaphragm using a strain gauge.

[Problem to be solved by the invention] Condensation, etc. may occur in the connection paths (B2) and (B3) that connect the gas supply path (G1) and the air supply path (A1) to the differential pressure sensor (30). , it is difficult to remove such condensation. As a result, connecting roads (B2), (B3)
There was a risk that water or the like would be trapped inside the sensor, making it impossible to accurately detect the differential pressure.

Furthermore, when performing detailed control such as setting a mixture ratio different from that during normal combustion immediately after ignition of the burner, it is necessary to detect a minute pressure difference.

However, in order to detect minute differential pressures, the area of the diaphragm is large, which means the sensor becomes a dog, and it is also necessary to amplify the detected value or use a highly sensitive one, which makes it expensive. There was a risk.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mixture ratio control device for a burner which is compact and inexpensive and can eliminate the above-mentioned conventional drawbacks and prevent erroneous detection due to dew condensation.

[Means to solve the problem]

In order to achieve this object, the characteristic configuration of the mixture ratio control device for a burner according to the present invention is such that the detection means includes a wind speed sensor provided in a bypass path that communicates the gas supply path and the air supply path. This is what is being done.

[For production]

When a difference occurs between the pressures of the gas supply path and the air supply path, wind having a wind speed corresponding to the pressure difference is generated in the bypass path.

Therefore, the pressure difference can be detected by detecting the wind direction and wind speed using a wind speed sensor.

Since the bypass passage communicates both supply passages, condensation does not occur, and even if condensation does occur, it can be removed by air purge or the like.

〔Effect of the invention〕

Therefore, an accurate differential pressure can be detected without being affected by dew condensation, etc., and as a result, efficient and stable combustion can be performed.

Further, even if the wind speed sensor has sufficient detection accuracy, it is inexpensive and compact, and furthermore, it is easy to install and adjust, and the circuit attached thereto is also inexpensive. Therefore, it is possible to contribute to making the mix ratio control device for a burner more compact and improving economic efficiency.

〔Example〕

An embodiment in which the present invention is applied to a water heater will be described based on the drawings.

As shown in FIG.
) and a gas supply path (G1) that supplies gas to the mixing section (2
) and an air supply path (A1) that supplies air to the burner (1
), a water heating heat exchanger (3), etc., which is heated by a water heater (3), etc., are provided to constitute a hot water supply device.

Two gas solenoid valves (4) are provided in the gas supply path (G1).

(5), and a gas proportional valve (6) as a gas amount adjusting means.
and a gas throttle (7).

A fan (8) is provided at the starting end of the air supply path (A1) as an air amount adjusting means, and an air throttle (8) is provided downstream of the fan (8).
9) is interposed.

Further, a bypass path (B1) is provided that communicates the gas supply path (G1) and the air supply path (A1), and the bypass path (
A wind speed sensor (10) is interposed in B1).

To explain the wind speed sensor (10), as shown in Fig. 3, a plurality of temperature sensors (26) are arranged around the heater (25), and the temperature distribution is detected by these temperature sensors (26). It is configured so that the wind direction and wind speed can be detected by doing so. Note that (27) in the figure is an ambient temperature sensor for temperature correction.

A water supply channel (W1) that supplies water to the heat exchanger (3) is equipped with a water supply temperature sensor (11) and a water flow sensor (12), and a water supply channel (W1) that supplies hot water to the hot water tap (14). W2) is equipped with a hot water supply sensor (15).

In the figure, (16) is the spark plug, and (17) is the burner (1
) is a flame rod that detects whether or not it is ignited.

These are each connected to a control device (H), and a remote controller (R) is connected to this control device (I4).

The remote controller (R) has an operation switch (20
), an operation lamp (21), a combustion lamp (22), and a hot water temperature adjustment button switch (23).

To explain the operation of the water heater, when the operation switch (20) is turned on, the water flow sensor (12)
) is greater than the set water amount, the gas solenoid valves (4) and (5) are opened to ignite the burner (1) and drive the fan (8) to start hot water supply.

The combustion amount of the burner (1) is then determined based on the target hot water temperature set by the hot water temperature adjustment button switch (23), the detected water supply temperature by the water supply temperature sensor (11), and the water amount detected by the water flow sensor (12). is calculated, and the opening degree of the gas proportional valve (6) is adjusted to achieve the combustion amount.

However, based on the deviation between the hot water temperature detected by the hot water supply part sensor (15) and the target hot water supply temperature, the opening degree of the gas proportional valve (6) is adjusted so that the hot water temperature detected by the hot water supply part sensor (15) matches the target hot water supply temperature. Add corrections.

Further, a target mixing ratio (K3) of gas and air in the mixing section (2) is set in advance in the control device (H). The mixing ratio (KX) of gas and air in the mixing section (2) is determined by the pressure difference (P) between the gas supply path (G1) and the air supply path (A1).
Corresponds to x). In other words, the mixture ratio (KX) is detected based on the information detected by the wind speed sensor (10). Then, based on the information detected by the wind speed sensor (10), the rotation speed of the fan (8) is controlled so that the mixture ratio (KX) becomes the target mixture ratio (K3).

That is, the wind speed sensor (10) corresponds to the detection means, and the control device (H) is used to constitute the target setting means (101) and the control means (100), respectively.

By the way, the target mixture ratio K,) are set to different values. In the initial mode, the pressure in the gas supply path (G1) is set to a predetermined value higher than the pressure in the air supply path (A1), while in the standard mode, both supply paths (G1),
The pressures in (A1) are set to be equal. Therefore, efficient combustion can be performed both immediately after ignition and afterward.

That is, in the initial mode, wind at a predetermined speed is detected from the gas supply path (G1) side to the air supply path (A1) side in the bypass path (B1), and in the standard mode, the bypass path So that the wind is not detected in (B1),
The rotation speed of each fan (8) will be adjusted.

Next, the operation of the control device (H) will be explained based on the flowchart shown in FIG.

First, it is determined whether the water amount is below the set value based on the detected value of the water amount sensor (12), and if it is below the set value, the process returns. Here, if hot water is currently being supplied, the process returns after executing the extinguishing process.

If the amount of water exceeds the set value, it is determined whether or not ignition is in progress, and if ignition is not in progress, ignition processing is executed to ignite the burner (1).

Next, it is determined whether a predetermined time (Δ1) has elapsed since the ignition.

The gas proportional valve (6) operates in the initial mode when the predetermined time (Δ1) has not elapsed, and in the standard mode after it has elapsed.
The opening degree of the fan (8) and the rotation speed of the fan (8) are controlled.

[Another example]

In the above embodiment, the gas amount is increased or decreased according to the load amount, and the air amount is increased or decreased according to the gas amount so that the wind speed becomes a predetermined value. It may be configured to be an air amount priority type in which the amount of air is increased or decreased depending on the amount of air, and the amount of gas is increased or decreased in accordance with the amount of air.

Moreover, in the above embodiment, regardless of the combustion amount of the burner (1),
The rotation speed of the fan (8) was adjusted so that the mixture ratio (KX) of gas and air was constant, but depending on the characteristics of the burner (1), the mixture ratio (KX) may vary depending on the combustion amount of the burner (1). KX
) may be changed.

In the above embodiment, the case where the mixture ratio control device for a burner is applied to a water heater is shown, but it can also be applied to a heater or the like.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the mixture ratio control device for a burner according to the present invention, FIG. 1 is a block diagram of the control configuration, FIG. 2 is a flowchart of control operation, FIG. 3 is a perspective view showing a wind speed sensor, and FIG. FIG. 4 is a block diagram of a control configuration showing a conventional example. (1)...Burner, (2)...Mixing section, (6)...Gas amount adjustment means, (8)...
...Air amount adjustment means, (10)...Detection means,
(100)...Goal setting means, (101)...
... Control means (G1) ... Gas supply path, (
A1)...Air supply path, (B1)...
Bypass path, (KX)...Mixing ratio, (K3)
...Target mixture ratio.

Claims (1)

[Claims] A mixing section (2) for supplying a mixture of combustion gas and air to the burner (1), and a gas amount adjusting means (6) for supplying gas to the mixing section (2). a gas supply path (G1) provided therein, and an air supply means (8) for supplying air to the mixing section (2).
); target setting means (100) for setting a target mixture ratio (Ks) of gas and air in the mixing section (2); and a detection means (10) for detecting the mixture ratio (Kx) of the gas and air in the mixing section (2) based on the detection information of the detection means (10). ) Control means (101) for controlling the gas amount adjusting means (6) or the air adjusting means (8) so that
), wherein the detection means (10) includes a bypass passage (B1) that communicates the gas supply passage (G1) and the air supply passage (A1).
A mixture ratio control device for a burner, which is configured by providing a wind speed sensor (10) at the top.