JPH05187630A - Burner - Google Patents

Abstract

PURPOSE:To make it possible to maintain stable combustion even when the range of regulation of the amount of combustion is wide, by controlling the amount of supply air so that the length of an inside flame formed by flame burner be maintained within set limits. CONSTITUTION:A pair of flame rods 15a and 15b for detecting the length of an inside flame (f) formed by a flame burner 11 are provided above a burner unit 1. The flame rods 15a and 15b are OFF when they are inside the inside flame (f) and ON when they are outside it. A controller 3 is given the information for controlling the amount of air supplied by a fan 13 so that the upper end of the inside flame (f) formed by the flame burner 11 be positioned at the middle between the flame rod l5a on the upper side and the flame rod 15b on the lower side. According to this constitution, deviation from the range of stable combustion can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a light burner having a large suction ratio of primary air and a rich burner having a suction ratio smaller than that of the light burner, and the light burner and the rich burner are alternately arranged. The present invention relates to a combustion apparatus provided with an air blowing unit that supplies primary air to the air and a control unit that controls an air blowing amount of the air blowing unit.

[0002]

2. Description of the Related Art The above-mentioned combustion apparatus is intended to suppress the production of NOx by rich and lean combustion. Conventionally, the control unit controls the air blowing unit so that the air blowing amount increases as the combustion amount increases so that the suction ratio is maintained at a predetermined value.

[0003]

When the suction ratio is maintained at a predetermined value as in the prior art described above, the jet speed of the air-fuel mixture becomes large when the combustion amount is adjusted to a large value. On the other hand, when the combustion amount is adjusted to be small, the jet speed of the air-fuel mixture becomes small. Therefore, when the adjustment range of the combustion amount is wide, the ejection speed of the air-fuel mixture may deviate from the stable combustion range when the combustion amount is adjusted to be large or small. An object of the present invention is to eliminate the above-mentioned conventional drawbacks and obtain a combustion device capable of maintaining stable combustion even when the combustion amount adjustment range is wide.

[0004]

In order to achieve this object, the combustion apparatus according to the present invention is characterized in that detection means for detecting the length of the internal flame formed by the light burner is provided.
The control means is configured to control the blown air amount so that the length is maintained within a set range based on the information of the detection means.

[0005]

When the jet speed of the air-fuel mixture is high, the length of the internal flame is long, and when the jet speed is low, the length of the internal flame is short. In other words, it can be determined whether the combustion range is stable by the length of the internal flame. Therefore, by setting the length of the internal flame within the stable combustion range and controlling the air flow rate so as to be maintained within that range, it is possible to prevent deviation from the stable combustion range.

[0006]

EFFECTS OF THE INVENTION Even when the combustion amount adjustment range is wide, it is possible to prevent deviation from the stable combustion range, so that the combustion performance of the combustion device can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a water heater will be described below with reference to the drawings. As shown in FIG. 1, a water heater including a burner unit 1, a heat exchanger 2 for heating water heated by the burner unit 1, and a controller 3 is provided to a hot water tap 4 via a hot water supply passage W2. It is connected. In the figure, R is a remote controller that gives a command to the water heater, and W1 is a water supply passage for the heat exchanger 2. The fuel gas supply path G1 for the burner unit 1 is provided with two opening / closing valves 6 and 7 for intermittently supplying the fuel gas and an electromagnetic gas amount adjusting valve 8 for adjusting the fuel gas supply. The water supply passage W1 is provided with a flow rate sensor S1 for detecting the water flow rate Q to the heat exchanger 2 and a water temperature sensor S2 for detecting the water temperature Ti entering the heat exchanger 2. A hot water temperature sensor S3 for detecting the outlet temperature To of the heat exchanger 2 is provided in the hot water supply passage W2.

The structure of the burner unit 1 will be described. A light burner 11 having a large primary air suction ratio and a rich burner 12 having a smaller suction ratio than the light burner 11 are alternately arranged to form the burner unit 1. Below the burner unit 1, a light burner 11 and a rich burner 1 are provided.
Fan 13 as a blower for supplying primary air to 2 and
However, above the burner unit 1, a pair of frame rods 15a and 15b as detection means for detecting the length of the internal flame f formed by the light burner 11 are provided, respectively. The frame rods 15a and 15b are OFF when inside the internal flame f, and are ON when outside. Then, as described later, the upper end of the internal flame f formed by the light burner 11 has an upper frame rod 15a and a lower frame rod 1
Information for controlling the amount of air blown by the fan 13 is provided to the controller 3 so as to be positioned in the middle of 5b.

The remote controller R is provided with an operation switch 20 for instructing start / stop of hot water supply operation, a target temperature setting device 21 for setting a target temperature Ts of hot water supply, and the like.

Next, the structure for controlling the combustion state of the water heater will be described. The flow sensor S
1, the water temperature sensor S2, the hot water temperature sensor S3, the frame rods 15a and 15b, and the remote controller R are connected to each other. The controller 3 then opens and closes the on-off valve 6, based on the preset information and various input information.
7. The operation of the gas amount adjusting valve 8 and the fan 13 is controlled. The heating amount Ip of the burner unit 1 is calculated based on the equation 1 so that the outlet temperature To becomes the target temperature Ts.

[0011]

## EQU1 ## Ip = Ka × (Ts−Ti) × Q + Kp × Δt + Ki × ∫Δtdt

Here, Ka, Kp, Ki are constants, and Δt is a deviation between the target temperature Ts and the outlet temperature To.

The reference air flow rate Vs of the fan 13 is obtained based on the equation 2 so as to be proportional to the heating amount Ip. Then, basically, the air flow rate Vp is controlled so as to match the reference air flow rate Vs.

[0014]

(2) Vs = Kv × Ip

Here, Kv is a constant. However, when the upper end of the internal flame f formed by the light burner 11 is located above the upper frame rod 15a, the air flow rate Vp is decreased by a predetermined amount ΔV regardless of the reference air flow rate Vs. Similarly,
When the upper end of the internal flame f is located below the lower frame rod 15b, the air flow rate Vs is independent of the reference air flow rate Vs.
Increase p by a predetermined amount ΔV. That is, the control means 1 for controlling the air flow rate Vp of the fan 13 using the controller 3
00 is configured.

Next, the procedure of combustion control will be described with reference to the flow charts shown in FIGS. First, the heating amount Ip of the burner unit 1 is calculated based on the equation 1. Next, the first flag F1 and the second flag F2 are checked. The first flag F1 indicates that the upper end of the internal flame f is located below the lower frame rod 15b.
The flag F2 is the frame rod 1 in which the upper end of the internal flame f is on the upper side.
5a, respectively. First flag F1
Is set, the air flow rate Vp is set to a predetermined value ΔV.
Increase. On the other hand, when the second flag F2 is set, the air flow rate Vp is decreased by a predetermined amount ΔV. When neither of the flags F1 and F2 is set, the reference air flow rate Vs is obtained based on Equation 2 and compared with the air flow rate Vp at that time. When the air flow rate Vp at that time is smaller than the reference air flow rate Vs, the air flow rate Vp is increased by a predetermined amount ΔV. On the other hand, when it is larger than the reference air flow rate Vs, the air flow rate Vp is decreased by a predetermined amount ΔV. When the air flow rate Vp at that time matches the reference air flow rate Vs, the air flow rate Vp is maintained as it is. Then, after a predetermined time has passed, the frame rods 15a and 15b are checked. When both the frame rods 15a and 15b are OFF, the second flag F2 is set. When the lower frame rod 15b is ON, the first flag F
Set 1.

[Other Embodiment] In the above embodiment, the set range of the length of the internal flame f formed by the light burner 11 is set by the pair of frame rods 15a and 15b. Various changes can be made to the concrete configuration of the means.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a block diagram of a control configuration.

FIG. 2 is a flowchart of control operation.

FIG. 3 is a flowchart of control operation.

[Explanation of symbols]

 11 Light Burner 12 Thick Burner 13 Blower Means 15a, 15b Detecting Means 100 Control Means Vp Blower Volume f Internal Flame

Claims (1)

[Claims] 1. A light burner (1) having a large primary air suction ratio.
1) and a rich burner (12) having the suction ratio smaller than the light burner (11) are alternately arranged, and primary air is supplied to the light burner (11) and the rich burner (12). A combustion device provided with a blower means (13) and a control means (100) for controlling the blown air amount (Vp) of the blower means (13), the internal flame formed by the light burner (11). Detection means (15a) and (15b) for detecting the length of (f) are provided, and the control means (100) includes the detection means (15a) and (15a).
A combustor configured to control the air flow rate (Vp) so that the length is maintained within a set range based on the information in (15b).