JP7006363B2 - Boiler device - Google Patents

Description

The present invention relates to a boiler device that burns fuel to generate steam.

Conventionally, there has been a combustion device in which a pressure regulating valve (so-called governor) is provided in the fuel supply path to maintain a constant pressure of the supplied fuel. Further, in such a combustion device, the pressure in the wind box for rectifying the combustion air is introduced into the diaphragm hole of the governor (for example, Patent Document 1). As a result, the secondary pressure of the governor can be reduced in conjunction with the pressure drop in the windbox, and the amount of fuel supplied can be reduced.

Japanese Unexamined Patent Publication No. 2006-38417

However, in a conventional combustion device, it is common to introduce a differential pressure between the combustion air and the outside air (atmosphere) into the governor. Therefore, for example, when the back pressure due to the exhaust gas from the combustion device is applied, the differential pressure introduced into the governor becomes small, and the pressure of the fuel to be supplied decreases. As a result, when back pressure is applied, the fuel supplied to the combustion air has a high air ratio, which causes misfire.

The present invention has been conceived in view of such circumstances, and an object of the present invention is to provide a boiler device capable of maintaining an air ratio as constant as possible without being affected by back pressure.

In order to achieve the above object, the boiler device according to a certain aspect of the present invention includes a boiler main body, a blower that blows air into the boiler main body through the air passage, and a first communication passage that communicates with the air passage. A second communication passage communicating with the boiler main body and a flow rate adjusting unit for adjusting the flow rate of fuel supplied to the boiler main body according to the differential pressure between the first communication passage and the second communication passage. The first communication passage is provided with a first decompression unit that reduces the pressure from the air passage.

According to the above configuration, the flow rate of fuel supplied to the boiler main body can be adjusted according to the differential pressure between the first passage and the second passage, so that the air ratio is constant without being affected by the back pressure. Can be maintained at. Further, the pressure from the air passage can be adjusted by the first decompression unit according to the specifications and design of the boiler device.

Preferably, the second passage is provided with a second decompression unit that reduces the pressure from the boiler body.

According to the above configuration, the pressure from the boiler main body can be adjusted by the second decompression unit according to the specifications and design of the boiler device.

Preferably, the flow path area of the second decompression section is larger than the flow path area of the first decompression section.

According to the above configuration, it is possible to prevent the second decompression unit from being clogged before the first decompression unit due to the influence of foreign matter or the like as much as possible. Further, if the first decompression unit is clogged, the air ratio becomes high and misfire occurs, so that the boiler device can be controlled on the safer side.

Preferably, the flow rate adjusting unit adjusts the opening degree according to the difference pressure between the pressure decompressed by the first decompression unit and the pressure decompressed by the second decompression unit and the pressure of the fuel to be supplied. The pressure regulating valve includes a pressure regulating valve to adjust the flow rate of the fuel to be supplied according to the opening degree.

According to the above configuration, the flow rate of the fuel can be mechanically adjusted by the pressure adjusting valve according to the differential pressure between the pressure decompressed by the first decompression unit and the pressure decompressed by the second decompression unit. ..

Preferably, the flow rate adjusting unit is a difference between the flow rate adjusting valve that adjusts the flow rate of the fuel supplied according to the opening degree and the difference pressure between the first passage and the second passage. It includes a differential pressure information output unit that outputs pressure information and a control unit that controls the opening degree of the flow rate adjusting valve based on the differential pressure information.

According to the above configuration, the opening degree of the flow rate adjusting valve is controlled by the control unit according to the differential pressure information for specifying the differential pressure between the first passage and the second passage, and the fuel is charged. The flow rate can be adjusted.

It is a figure which shows typically the structure of the boiler apparatus which concerns on Embodiment 1. FIG. It is a figure which shows typically the structure of the boiler apparatus which concerns on Embodiment 2.

<Embodiment 1>
Hereinafter, the boiler device 1 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram schematically showing a configuration of a boiler device 1 according to a first embodiment of the present invention.

The boiler device 1 includes a boiler main body 2 that burns fuel to generate steam, a blower 3 that sends air into the boiler main body 2 through a blower passage 30, and a flue 4 that derives exhaust gas from the boiler main body 2. And a fuel supply line (fuel supply path) 5 for supplying fuel to the boiler main body 2. Although an example in which the fuel is a gas will be described, the fuel is not limited to a gas such as a gas, but may be a liquid such as oil.

The fuel supply line 5 is connected to the air passage 30. The fuel supplied from the fuel supply line 5 is mixed with the air blown from the blower 3 in the air passage 30 and supplied to the burner 20 in the boiler main body 2.

The fuel supply line 5 is provided with an on-off valve 61 (solenoid valve) for opening and closing the flow path, and a governor 62 that can adjust the flow rate of the fuel supplied to the boiler main body 2 and also has a shut-off function. There is. The governor 62 is arranged on the downstream side of the on-off valve 61.

The governor 62 on the downstream side constitutes a flow rate adjusting unit 8 that adjusts the flow rate of the fuel supplied to the boiler main body 2. That is, the governor 62 functions as a pressure adjusting valve for adjusting the pressure of the fuel supplied to the boiler main body 2. The governor 62 in the present embodiment is configured so that the opening degree changes according to the differential pressure between the pressure in the air passage 30 and the pressure in the boiler main body 2. The governor 62 is a pressure equalizing valve whose opening degree is mechanically adjusted so that the differential pressure to be introduced and the pressure of the fuel to be supplied (pressure on the secondary side) are equalized. A branch path 53 is provided from the downstream flow path of the governor 62. The governor 62 can adjust the opening degree so that the pressure on the secondary side obtained from the branch passage 53 becomes the differential pressure between the pressure in the air passage 30 to be introduced and the pressure in the boiler main body 2.

Specifically, the boiler device 1 includes a first communication passage 51 communicating with the air passage 30 and a second communication passage 52 communicating with the boiler main body 2 (inside the furnace). The second continuous passage 52 is arranged so as to join the first continuous passage 51, and for example, the air flowing into the first continuous passage 51 is blown into the boiler main body 2 according to the pressure in the boiler main body 2. It is configured in. As a result, the pressure of the gas passing through the passage on the downstream side of the confluence with the second passage 52 on the first passage 51 corresponds to the pressure difference between the pressure in the air passage 30 and the pressure in the boiler main body 2. do. Further, the first continuous passage 51 is connected to the governor 62 by a passage on the downstream side of the confluence with the second continuous passage 52. As a result, the differential pressure between the pressure in the air passage 30 and the pressure in the boiler main body 2 can be introduced into the governor 62. The governor 62 changes the opening degree according to the pressure of the gas introduced from the first continuous passage 51.

Here, in the conventional mode in which the flow rate is adjusted according to the differential pressure between the "pressure in the air passage 30" and the "pressure of the outside air" (hereinafter referred to as "comparative example"), the exhaust gas from the boiler main body 2 is used. When back pressure is applied, the differential pressure between the "pressure in the air passage 30" and the "pressure of the outside air" can be reduced. Therefore, the differential pressure introduced into the governor 62 becomes small. As a result, when the back pressure from the boiler main body 2 is applied, the pressure of the fuel to be supplied decreases, and the fuel supplied to the burner 20 becomes a high air ratio to the amount of air blown from the blower 3, and there is a risk of misfire. was there.

On the other hand, in the present embodiment, the differential pressure between the "pressure in the air passage 30" and the "pressure in the boiler main body 2 (inside the furnace)" is introduced into the governor 62. Therefore, the pressure (flow rate) of the fuel supplied to the burner 20 can be adjusted with respect to the amount of air blown from the blower 3 so as to maintain the air ratio without being affected by the back pressure of the boiler main body 2. .. As a result, back pressure resistance can be improved.

Further, the first continuous passage 51 is provided with a (first) decompression unit 71 for reducing the pressure of the gas flowing in from the air passage 30. Similarly, the second passage 52 is provided with a (second) decompression unit 72 that reduces the pressure of the gas flowing in from the boiler main body 2. The decompression unit 71 and the decompression unit 72 are, for example, orifices, but are not limited to these, and may be valves whose opening degree can be adjusted. By adjusting the ratio of depressurization (flow path area) by each of the decompression unit 71 and the decompression unit 72, it is possible to conform to the specifications or design of the boiler device 1.

Further, the flow path area (orifice diameter) of the decompression section 72 of the second continuous passage 52 is larger than the flow path area (orifice diameter) of the decompression section 71 of the first continuous passage 51. As a result, even if a foreign substance is mixed in the first continuous passage 51 or a foreign substance is accumulated in each of the decompression section 71 and the decompression section 72, the second communication passage is more than the decompression section 71 of the first communication passage 51. It is possible to reduce the possibility that the pressure reducing portion 72 of the 52 is clogged first. As a result, for example, when the decompression portion 72 of the second passage 52 is clogged before the decompression portion 71 of the first passage 51, the pressure of the air flowing into the first passage 51 is introduced into the governor 62 as it is. In the present embodiment, it is possible to avoid a dangerous state of incomplete combustion and excessive CO as a result of a low air ratio in which the amount of fuel supplied to the burner 20 becomes too large. Further, if the decompression portion 71 of the first communication passage 51 is clogged, the pressure introduced into the governor 62 becomes small, so that the fuel supplied to the burner 20 is reduced (high air ratio) to maintain the pressure. Since the fire is misfired without being able to generate a flame, the boiler device 1 can be controlled so as to be on the safer side.

<Embodiment 2>
In the first embodiment, the configuration in which the flow rate adjusting unit 8 includes the mechanical governor 62 and mechanically adjusts the flow rate of the fuel supplied to the boiler main body 2 has been described, whereas in the second embodiment, the boiler main body has been described. A configuration in which the flow rate of the fuel supplied to No. 2 is electronically adjusted by the control unit will be described. Hereinafter, only the differences from the boiler device 1 according to the first embodiment will be described in detail.

FIG. 2 is a diagram schematically showing the configuration of the boiler device 1A according to the second embodiment of the present invention. With reference to FIG. 2, in the present embodiment, the fuel supply line 5 is provided with a control valve 81 in addition to the on-off valve 61 and the governor 62 described above. The adjusting valve 81 is a motor valve provided on the downstream side of the governor 62 and whose opening degree is adjusted by the control unit 9. The regulating valve 81 is not limited to the motor valve as long as it regulates the flow rate of the fuel, and may be, for example, a pneumatic control valve. The control unit 9 is realized by an arithmetic processing unit such as a CPU.

In the present embodiment, the first-passage passage 51 and the second-passage passage 52 are arranged in series, and the first-passage passage 51 is not connected to the governor 62. That is, the first passage 51 and the second passage 52 are realized by a duct having one end connected to the air passage 30 and the other end connected to the boiler main body 2.

A pressure sensor 73 is provided on the duct. The pressure sensor 73 outputs differential pressure information for specifying the differential pressure between the pressure of the gas in the first communication passage 51 and the pressure of the gas in the second communication passage 52.

Also in this embodiment, the decompression portions 71 and 72 are provided in each of the first-passage passage 51 and the second-passage passage 52, respectively. The decompression unit 71 is provided on the air passage 30 side of the pressure sensor 73, and the decompression unit 72 is provided on the boiler main body 2 side of the pressure sensor 73.

The pressure sensor 73 is electrically connected to the control unit 9. As a result, the differential pressure information from the pressure sensor 73 can be input to the control unit 9. The analog signal output from the pressure sensor 73 is converted into a digital signal and input to the control unit 9.

The control unit 9 adjusts the opening degree of the adjusting valve 81 based on the differential pressure information input from the pressure sensor 73. The control unit 9 transmits an opening degree specifying signal for specifying the opening degree to the adjusting valve 81 based on the opening degree adjusting information stored in advance in the memory 10. As a result, the adjusting valve 81 can adjust the flow rate of the fuel supplied to the boiler main body 2 by controlling the opening degree according to the differential pressure between the pressure in the air passage 30 and the pressure in the boiler main body 2. .. The opening degree adjustment information may be, for example, a table capable of specifying the opening degree of the adjusting valve 81 according to the differential pressure, or for specifying the opening degree of the adjusting valve 81 according to the differential pressure. It may be an arithmetic expression.

Conventionally, for example, a punching metal or the like is provided in the air passage 30 and the amount of combustion air is calculated from the pressure loss before and after the punching metal. However, in such a case, since a considerable amount of pressure is lost due to the punching metal, it is necessary to adopt a blower having high performance, which is costly. On the other hand, in the second embodiment, it is possible to calculate the flow rate of the combustion air by using the fixed pressure loss from the air passage 30 to the boiler main body 2 (inside the passage) without using a punching metal or the like. Therefore, at least the cost required for the blower can be suppressed.

The present invention is not limited to the above-described embodiment, and various modifications and applications are possible. Hereinafter, modifications and the like of the above-described embodiments applicable to the present invention will be described.

The boiler device 1 in the above embodiment includes a fuel supply line for supplying gas and a fuel supply line for supplying oil, and either a mode in which gas is used as fuel or a mode in which oil is used as fuel. It may be something that can be controlled by switching to.

In the above embodiment, the orifice is exemplified as the decompression unit 71 and the decompression unit 72. However, the decompression unit 71 and the decompression unit 72 are not limited to those capable of depressurizing, and may be valves whose opening degree can be adjusted. Further, in the above-described embodiment, an example in which a pressure reducing portion is provided in each of the first-passage passage 51 and the second-passage passage 52 has been described. However, the present invention is not limited to this, and each of the first-passage passage 51 and the second-passage passage 52 may not be provided with a pressure reducing portion, and any of the first-passage passage 51 and the second-passage passage 52. A decompression unit may be provided only on one side (for example, the first continuous passage 51). In this case, in the first embodiment, for example, the size of the diameter of each of the first-passage passage 51 and the second-passage passage 52 may be adjusted according to the specifications or design of the boiler device 1, etc. In the second embodiment, the opening degree adjustment information may be adjusted according to, for example, the specifications or design of the boiler device 1.

In the second embodiment, an example in which the governor 62 is provided on the downstream side of the on-off valve 61 has been described, but the present invention is not limited to this, and the flow path on the downstream side of the on-off valve 61 is the same as that of the on-off valve 61. A valve (solenoid valve) for opening and closing may be provided.

The embodiments disclosed this time should be considered to be exemplary and not restrictive in all respects. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Boiler device 1A Boiler device 2 Boiler body 3 Blower 4 Flue 5 Fuel supply line 8 Flow control unit 9 Control unit 10 Memory 20 Burner 30 Blower path 51 1st station 52 2nd station 53 Branch path 61 Open / close valve 62 Governor 71 Pressure reducing part 72 Pressure reducing part 73 Pressure sensor 81 Adjusting valve

Claims (5)

With the boiler body,
A blower that blows air into the boiler body through the air passage, and
The first communication passage that communicates with the air passage and
The second communication passage that communicates with the boiler body and
It is provided with a flow rate adjusting unit that adjusts the flow rate of the fuel supplied to the boiler main body according to the differential pressure between the first passage and the second passage .
A boiler device provided with a first decompression unit for reducing the pressure from the air passage in the first continuous passage . The boiler device according to claim 1 , wherein the second communication passage is provided with a second decompression unit that reduces the pressure from the boiler main body. The boiler device according to claim 2 , wherein the flow path area of the second decompression section is larger than the flow path area of the first decompression section. The flow rate adjusting unit adjusts the opening degree according to the differential pressure between the pressure decompressed by the first decompression unit and the pressure decompressed by the second decompression unit and the pressure of the fuel to be supplied. Including the valve
The boiler device according to claim 2 or 3 , wherein the pressure adjusting valve adjusts the flow rate of fuel to be supplied according to an opening degree. The flow rate adjusting unit
A flow rate adjustment valve that adjusts the flow rate of fuel supplied according to the opening,
A differential pressure information output unit that outputs differential pressure information for specifying the differential pressure between the first passage and the second passage.
The boiler device according to claim 1 , further comprising a control unit that controls an opening degree of the flow rate adjusting valve based on the differential pressure information.

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