JPH0989222A - Gas combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the promotion of local deterioration and improve durability by a method wherein combustion is effected by all combustion blocks upon high load combustion while the combustion is effected in only one combustion block upon low load combustion and the accumulated combustion time is unified as far as possible while increasing a turn down ratio. SOLUTION: A plurality of pieces of burners are divided into a plurality of combustion blocks 8, 9, 10 and respective combustion blocks 8, 9, 10 are provided with a fuel gas supplying passage, supplying fuel, gas individually, while respective fuel gas supplying passages are provided with an intermittent valve. A control means, controlling the operation of the intermittent valve, controls so as to burn all burners of all combustion blocks 8, 9, 10 upon high load combustion and controls so as to burn the burners of only one combustion block 8 upon low load combustion. Further, the control means controls so as to switch the operating block into the combustion blocks 8, 9 automatically upon low load combustion in the gas combustion device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention divides a plurality of burners into a plurality of combustion blocks, and provides each of the combustion blocks with a fuel gas supply path for supplying a fuel gas to each of the combustion blocks. In addition to providing an on / off valve for intermittently supplying gas, a control means for controlling the operation of these on / off valves is provided, and this control means burns all burners of all combustion blocks during high load combustion, and one burner during low load combustion. The present invention relates to a gas combustion device which controls so that only the burner of the combustion block is burned.

[0002]

2. Description of the Related Art In a gas combustion apparatus having such a structure, the turndown ratio between high-load combustion and low-load combustion can be increased, and it is very convenient, so that it is widely used in various apparatuses. There is. By the way, in the conventionally known gas combustion apparatus of this type, only the burners of the same combustion block are always burned at the time of low load combustion.

[0003]

Therefore, regarding the burner of the combustion block that burns at the time of low load combustion, not only at the time of low load combustion, but also at the time of high load combustion, depending on the case, there are cases of low load and high load. There is a drawback in that even during medium load combustion during that period, the combustion is performed, and the cumulative combustion time becomes longer than that of the burners of other combustion blocks, and the deterioration becomes faster accordingly. As described above, if the deterioration of the specific combustion block is accelerated, the durability of the combustion device itself depends on the specific combustion block, and there is room for improvement in this respect.

In addition, when this type of gas combustion apparatus is used in a hot water supply apparatus having a heat exchanger for heating water, only the portion of the heat exchanger corresponding to the combustion block that burns at the time of low load combustion is local. Not only promotes local deterioration of the heat exchanger, but also causes combustion products to adhere locally and disturb the flow of combustion air, resulting in gas combustion. Also had the drawback of having an adverse effect.

The present invention focuses on the above-mentioned conventional drawbacks, and an object thereof is to burn all the combustion blocks at the time of high load combustion, and to burn only one combustion block at the time of low load combustion to reduce the turndown ratio. Even though it is large, the cumulative combustion time of each combustion block is made as uniform as possible, thereby preventing local deterioration from being promoted and improving durability, and it is used in a water heater equipped with a heat exchanger. In some cases, it is possible to prevent the local adhesion of combustion products to the heat exchanger as much as possible, maintain the flow of combustion air well for a long time, and provide a gas combustion device that can perform good gas combustion. It is in.

[0006]

In order to achieve this object, according to the invention as set forth in claim 1, all burners of all combustion blocks are combusted at the time of high load combustion, and one combustion block is combusted at the time of low load combustion. The control means for controlling the burner to burn only the burner automatically switches and controls the combustion block to be burned at the time of low load combustion. It is possible to avoid an extremely long cumulative combustion time, to make the cumulative combustion time of each combustion block uniform as much as possible, and improve the durability as a whole.

According to the second aspect of the present invention, the accumulated combustion time of each combustion block is controlled by switching the combustion block to be burned at the time of low load combustion every time the combustion time of low load combustion reaches the set time. Can be made uniform, and the durability of the device can be improved.

According to the third aspect of the invention, every time the number of low-load combustions reaches the set number, the combustion blocks to be burned during the low-load combustion are switched and controlled. The time can be made uniform, and the durability of the device can be improved.

According to the invention described in claim 4, the plurality of combustion blocks are composed of a light combustion block having a light burner burner and a rich combustion block having a rich burner,
Since the rich combustion blocks are positioned on both sides of the light combustion block, at the time of high-load combustion, combustion of all the combustion blocks results in rich and light combustion, for example, a high wobbe with a high combustion temperature and a large amount of NOx generation. Even when an index gas is used, stable combustion is possible while suppressing the generation of NOx as much as possible, and the turndown ratio can be increased by burning one of the rich combustion blocks during low load combustion. .

According to the fifth aspect of the present invention, the fuel gas supply passage for supplying the fuel gas to each combustion block separately is branched from the main fuel gas supply passage, and the main fuel gas supply passage upstream from the branch point. Since an electromagnetic proportional valve is installed in the fuel cell, the amount of fuel gas supplied is controlled by a common electromagnetic proportional valve provided in the main fuel gas supply path during both high load combustion and low load combustion. As a result, the number of electromagnetic proportional valves can be reduced as compared with the case where electromagnetic proportional valves are separately provided in the fuel gas supply passages of each combustion block, and the cost can be reduced.

According to the sixth aspect of the present invention, by using this gas combustion apparatus in a hot water supply apparatus having a heat exchanger for heating water, the combustion products are locally attached to the heat exchanger. It is possible to perform good gas combustion while maintaining the flow of the combustion air as desired for a long period of time.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a gas combustion apparatus according to the present invention will be described with reference to the drawings. FIG. 1 shows an outline of the entire hot water supply apparatus, which includes a fin-tube type heat exchanger 2 for heating water supplied from a water supply passage 1, a gas burner 3 for heating the heat exchanger 2, and the like. The hot water heated by the heat exchanger 2 is discharged from the hot water tap 5 through the hot water supply passage 4 communicating with the heat exchanger 2,
The water supply path 1 is provided with a water flow switch 6 which is turned on by a constant amount of water flow and a thermistor 7a for detecting the water supply temperature, and the hot water supply path 4 is provided with a thermistor 7b for detecting the hot water supply temperature.

The gas burner 3 burns a rich air-fuel mixture having a small primary air mixing ratio, a first rich combustion block 8 and a second rich combustion block 9, and these first rich combustion block 8 and second rich combustion block 9. A light combustion block 1 located between and for burning a light air-fuel mixture having a large primary air mixing ratio
The three fuel gas supply passages 12 and 1 which are divided into three combustion blocks 0 and are branched from the main fuel gas supply passage 11.
3, 14 are respectively connected to these three combustion blocks 8, 9, 10 so as to supply the fuel gas separately. These fuel gas supply passages 12, 13, 14 are provided with electromagnetic disconnect valves 15, 16, 1 for disconnecting the supply of the fuel gas.
7 is provided, and in the main fuel gas supply path 11 upstream of the branch points of the fuel gas supply paths 12, 13, and 14, an electromagnetic safety valve 19 similar to the electromagnetic proportional valve 18 with a governor is provided.
Are provided.

Each of the first rich combustion block 8 and the second rich combustion block 9 is composed of a total of eight flat burners for rich combustion that burn a rich air-fuel mixture. Are arranged along the direction orthogonal to the paper surface of FIG. 1, and the igniters 20 and 21 for ignition and the frame rods 22 and 23 for detecting ignition are provided in the rich combustion blocks 8 and 9, respectively. It is provided separately. Between the first rich combustion block 8 and the second rich combustion block 9, a lean combustion block 10 composed of a burner for lean combustion is disposed, and the burners for rich combustion and the lean burners of the rich combustion blocks 8 and 9 are provided. A fan 24 is provided to supply primary air and secondary air for combustion to the burner for light combustion of the combustion block 10 and to supply cooling air.

The hot water supply apparatus having such a configuration is constructed so that its operation is controlled by the control means H comprising a microcomputer. Therefore, the water flow switch 6, the thermistors 7a and 7b, and the intermittent connection are provided in the control means H. Valves 15, 16,
17, electromagnetic proportional valve 18, safety valve 19, igniter 2
0, 21, frame rods 22, 23, a fan 24, etc. are connected. A remote controller R for giving a control command is wirelessly or wired connected to the control means H, and the remote controller R has an operating switch 25 for instructing start and stop of hot water supply and a temperature setting for setting the hot water supply temperature. A switch 26 and the like are provided.

Next, the control operation of the hot water supply device will be described. Hot water can be supplied by turning on the operation switch 25 of the remote controller R. In this state, when the hot water tap 5 is opened and more water than the set amount of water flows through the water supply passage 1, the water flow sensor 6 is turned on, the fan 24 is rotationally driven, and the safety valve 19 is opened. Intermittent valve 15, 16, 1
7 is opened, the proportional valve 18 is set to the warm ignition position, and ignition is performed by the igniters 20 and 21. At that time, based on the temperature set by the temperature setting switch 26 of the remote controller R and the feed water temperature detected by the thermistor 7a, it is judged whether or not the control means H is the high load combustion, and if it is the high load combustion, the intermittent valve 15, All of the valves 16 and 17 are opened, and as shown in FIG. 2A, the first and second rich combustion blocks 8,
9 and the lean burn block 10 to perform rich and lean combustion, and based on the set temperature and the detected feed water temperature, the gas burner 3
The fuel supply amount Ip is calculated to adjust the opening of the proportional valve 18, and the opening of the proportional valve 18 is finely adjusted based on the hot water supply temperature detected by the thermistor 7b.

In the case of low-load combustion, the intermittent valves 16 and 17 are closed, and only the intermittent valve 15 is opened. As shown in FIG. The rich combustion is performed only by the burner for rich combustion, and if the combustion is medium load between high load and low load, the intermittent valve 17 is closed and the intermittent valves 15 and 16 are opened. As shown in (b) of FIG.
The first rich burn block 8 and the second rich burn block 9 perform a rich burn by a total of 16 burners for rich burn. Even in this low load combustion and in the middle load combustion,
Similar to the above-described high load combustion, the control means H causes the remote controller R to
Temperature set by the temperature setting switch 26 and the thermistor 7
The fuel supply amount Ip to the gas burner 3 is calculated based on the detected water supply temperature by a, the opening of the proportional valve 18 is adjusted, and the opening of the proportional valve 18 is finely adjusted based on the detected hot water temperature by the thermistor 7b. The temperature of the hot water discharged from the hot water tap 5 is controlled to reach the set temperature.

When the accumulation of the rich combustion time by only the first rich combustion block 8 in the low load combustion reaches a certain set time, the intermittent valves 15 and 17 are closed in the next low load combustion. , Only the intermittent valve 16 is opened, and as shown in FIG. 2D, the rich combustion is performed only by the second rich combustion block 9, and the rich combustion time is accumulated only by the second rich combustion block 9. However, when the set time is reached, the control means H automatically controls the switching so that the rich combustion is performed only by the first rich combustion block 8 again at the next low load combustion. .

[Another Embodiment] In the above-described embodiment, another one occurs every time the accumulation of rich combustion time by only the first rich combustion block 8 or the second rich combustion block 9 in low load combustion reaches a certain set time. Although the switching control was performed so that only the rich combustion block of No. 1 was burned, the first rich combustion block 8 or the second rich combustion block 9 in the low load combustion.
It is also possible to count the number of times of rich combustion by only and perform switching control so that only the other rich combustion blocks are burned every time the accumulation of the times of rich combustion reaches a certain set number. In this case, the set time and the set number of times can be appropriately selected. For example, when the switching is controlled by the set number of times, the switching can be controlled so that only the other rich combustion blocks are burned each time.

Also, in the high load combustion, the embodiment in which the rich and lean combustion is executed by the two rich combustion blocks 8 and 9 and the single lean combustion block 10 has been shown, but the dense and lean combustion is not necessarily executed in the high load combustion. Gas burner 3 is composed of only a plurality of rich combustion burners, and the plurality of rich combustion burners are divided into a plurality of combustion blocks.
It is also possible to configure all the burners for rich combustion to burn at the time of high load combustion. On the contrary, gas burner 3
Is composed of multiple burners for rich combustion and burners for lean combustion.The burner for rich combustion and the burner for lean combustion are divided into multiple blocks for rich and lean combustion, and rich and lean combustion is performed even at low load combustion. Can also be configured to perform.

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 configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an entire water heater.

FIG. 2 is a diagram showing a combustion state of a gas combustion device.

[Explanation of symbols]

 2 heat exchanger 8,9 rich combustion block 10 light combustion block 11 main fuel gas supply passage 12,13,14 fuel gas supply passage 15,16,17 on / off valve 18 electromagnetic proportional valve H control means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Mochiki 1-2-1 Oka, Minami-shi, Minato-ku, Osaka, Osaka Prefecture Harman Co., Ltd.

Claims (6)

[Claims] 1. A plurality of burners are divided into a plurality of combustion blocks (8), (9), (10), and a fuel gas is supplied to each combustion block (8), (9), (10) separately. Fuel gas supply paths (12), (13), (14)
Each of these fuel gas supply paths (12), (13), (14)
Intermittent valves (15) and (1) for intermittently supplying fuel gas to
6) and (17) are provided, and these on-off valves (1
5), (16), (17) control means (H) for controlling the operation is provided, this control means (H) at the time of high load combustion, all combustion blocks (8), (9), (10) A burner for controlling all burners to burn and to burn only one burner of one combustion block (8) at low load combustion, wherein the control means (H) burns at low load combustion A gas combustion device that automatically controls switching between blocks (8) and (9). 2. The control means (H) switches and controls the combustion blocks (8), (9) to be combusted during low load combustion every time the combustion time due to low load combustion reaches a set time. Gas combustion equipment. 3. The control means (H) switches and controls the combustion blocks (8), (9) to be combusted during low load combustion every time the number of low load combustions reaches a set number. Gas combustion equipment. 4. The plurality of combustion blocks (8),
(9) and (10) are a lean combustion block (10) having a burner for burning lean mixture and a rich combustion block (8), (9) having a burner for burning rich mixture that burns rich mixture. ) And the light burning block (1
0), the rich combustion blocks (8), (9) are positioned on both sides of the rich combustion blocks (8), (9) during low load combustion.
The gas combustion apparatus according to claim 1, 2 or 3, which burns one of the above. 5. The combustion blocks (8), (9),
Fuel gas supply passages (12), (13), and (14) for separately supplying fuel gas to (10) are connected to the main fuel gas supply passage (1
The gas combustion apparatus according to claim 1, 2, 3 or 4, wherein the main fuel gas supply path (11) upstream from the branch point is provided with an electromagnetic proportional valve (18). 6. The gas combustion apparatus according to claim 1, 2, 3, 4 or 5, wherein the gas combustion apparatus is a combustion apparatus for a hot water supply apparatus including a heat exchanger (2) for heating water.