JP2019143914A - Boiler device - Google Patents

Abstract

To provide a boiler device that can maintain an air ratio as constantly as possible free from influence from back pressure.SOLUTION: A boiler device includes: a boiler body 2; a blower 3 for sending air into the boiler body 2 through an air flow passage 30; a first communication passage 51 communicated to the air flow passage 30; a second communication passage 52 communicated to the boiler body 2 (inside of furnace); and a governor 62 serving as a flow rate adjustment part for adjusting a flow rate of fuel to be supplied to the boiler body 2 in accordance with a differential internal pressure between the first communication passage 51 and the second communication passage 52.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a boiler device that generates steam by burning fuel.

  Conventionally, there has been a combustion apparatus that is provided with a pressure regulating valve (so-called governor) in a fuel supply path to maintain a constant pressure of the supplied fuel. Moreover, in such a combustion apparatus, there exist some which introduce | transduce the pressure in the wind box for rectifying combustion air into the diaphragm hole of a governor (for example, patent document 1). Thereby, the secondary pressure of the governor can be lowered in conjunction with the pressure drop in the wind box, and the supplied fuel can be reduced.

JP 2006-38417 A

  However, in a conventional combustion apparatus, it is common to introduce a differential pressure between combustion air and outside air (atmosphere) into the governor. For this reason, for example, when back pressure due to exhaust gas from the combustion apparatus is applied, the differential pressure introduced into the governor is reduced, and the pressure of the supplied fuel is reduced. As a result, when back pressure is applied, the fuel supplied to the combustion air has a high air ratio and causes a 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 the air ratio as constant as possible without being affected by back pressure.

  In order to achieve the above object, a boiler device according to an aspect of the present invention includes a boiler body, a blower that sends air into the boiler body through a blower path, a first communication path that communicates with the blower path, A second communication path that communicates with the boiler body, and a flow rate adjusting unit that adjusts a flow rate of fuel supplied to the boiler body in accordance with a differential pressure between the first communication path and the second communication path. Prepare.

  According to said structure, since the flow volume of the fuel supplied to a boiler main body can be adjusted according to the differential pressure | voltage between the inside of a 1st communicating path and the 2nd communicating path, an air ratio is fixed without being influenced by a back pressure. Can be maintained.

  Preferably, the first communication passage is provided with a first pressure reducing portion for reducing the pressure from the air blowing path.

  According to said structure, the pressure from a ventilation path can be adjusted with a 1st pressure reduction part according to the specification, design, etc. of a boiler apparatus.

  Preferably, the second communication passage is provided with a second pressure reducing portion for reducing the pressure from the boiler body.

  According to said structure, the pressure from a boiler main body can be adjusted with a 2nd pressure reduction part according to the specification, design, etc. of a boiler apparatus.

  Preferably, the flow path area of the second pressure reducing part is larger than the flow path area of the first pressure reducing part.

  According to said structure, it can avoid as much as possible that a 2nd pressure reduction part is blocked before the 1st pressure reduction part by the influence of a foreign material etc. Further, if the first decompression unit is clogged, the air ratio becomes high and misfires occur, so that the boiler device can be controlled more safely.

  Preferably, the flow rate adjusting unit adjusts the opening according to a differential pressure between the pressure reduced by the first pressure reducing unit and the pressure reduced by the second pressure reducing unit, and the pressure of the supplied fuel. The pressure regulating valve regulates the flow rate of the fuel to be supplied according to the opening degree.

  According to said structure, according to the differential pressure | voltage of the pressure decompressed by the 1st pressure reduction part and the pressure decompressed by the 2nd pressure reduction part, the flow volume of a fuel can be adjusted mechanically with a pressure control valve. .

  Preferably, the flow rate adjusting unit is configured to adjust a flow rate of a fuel to be supplied in accordance with an opening degree, and a difference for specifying a differential pressure between the first communication path and the second communication path. A differential pressure information output unit that outputs pressure information; and a control unit that controls the opening of the flow rate adjusting valve based on the differential pressure information.

  According to the above configuration, the opening 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 communication path and the second communication path, 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. FIG.

<Embodiment 1>
Below, the boiler apparatus 1 which concerns on Embodiment 1 of this invention is demonstrated, referring FIG. FIG. 1 is a diagram schematically showing a configuration of a boiler apparatus 1 according to Embodiment 1 of the present invention.

  The boiler device 1 includes a boiler body 2 that burns fuel to generate steam, a blower 3 that sends air into the boiler body 2 via a blower passage 30, and a flue 4 that extracts exhaust gas from the boiler body 2. And a fuel supply line (fuel supply path) 5 for supplying fuel to the boiler body 2. The fuel is described as an example of gas, but it is not limited to gas such as gas but may be 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 blower passage 30 and supplied to the burner 20 in the boiler body 2.

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

  The downstream governor 62 constitutes a flow rate adjusting unit 8 that adjusts the flow rate of the fuel supplied to the boiler body 2. That is, the governor 62 functions as a pressure adjusting valve that adjusts the pressure of the fuel supplied to the boiler body 2. The governor 62 in the present embodiment is configured such that the opening degree changes in accordance with the differential pressure between the pressure in the blower passage 30 and the pressure in the boiler body 2. The governor 62 is a pressure equalizing valve whose opening degree is mechanically adjusted so that the introduced differential pressure and the pressure of the supplied fuel (secondary pressure) 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 a differential pressure between the pressure in the air passage 30 to be introduced and the pressure in the boiler body 2.

  Specifically, the boiler device 1 includes a first communication path 51 that communicates with the blower passage 30 and a second communication path 52 that communicates with the boiler body 2 (inside the furnace). The second communication path 52 is arranged so as to merge with the first communication path 51, and for example, air that has flowed into the first communication path 51 is blown into the boiler body 2 according to the pressure in the boiler body 2. It is configured. As a result, the pressure of the gas passing through the downstream passage with respect to the second communication passage 52 on the first communication passage 51 corresponds to the pressure difference between the pressure in the blower passage 30 and the pressure in the boiler body 2. To do. Further, the first communication path 51 is connected to the governor 62 through a path downstream from the junction with the second communication path 52. Thereby, the differential pressure | voltage between the pressure in the ventilation path 30 and the pressure in the boiler main body 2 can be introduce | transduced into the governor 62. FIG. The governor 62 changes the opening degree according to the pressure of the gas introduced from the first communication path 51.

  Here, in the conventional form (hereinafter referred to as “comparative example”) in which the flow rate is adjusted in accordance with the differential pressure between the “pressure in the air passage 30” and the “pressure of the outside air”, the exhaust gas from the boiler body 2 is used. When back pressure is applied, the differential pressure between “pressure in the air passage 30” and “pressure of the outside air” can be reduced. For this reason, the differential pressure introduced into the governor 62 is reduced. As a result, when the back pressure from the boiler body 2 is applied, the pressure of the fuel to be supplied is reduced, and the fuel supplied to the burner 20 with respect to the amount of air blown from the blower 3 is reduced to a high air ratio. was there.

  On the other hand, in the present embodiment, a differential pressure between “the pressure in the blower passage 30” and “the pressure in the boiler body 2 (in the furnace)” is introduced into the governor 62. For this reason, 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 body 2. . As a result, the back pressure resistance can be improved.

  Further, the first communication passage 51 is provided with a (first) decompression unit 71 that decompresses the pressure of the gas flowing in from the air passage 30. Similarly, the second communication path 52 is provided with a (second) decompression section 72 that decompresses the pressure of the gas flowing in from the boiler body 2. The decompression unit 71 and the decompression unit 72 are, for example, orifices, but are not limited thereto, and may be valves that can be adjusted in opening. By adjusting the ratio (flow channel area) of decompression by each of the decompression unit 71 and the decompression unit 72, the specification or design of the boiler device 1 can be adapted.

  Further, the flow passage area (orifice diameter) of the pressure reducing portion 72 of the second communication passage 52 is larger than the flow passage area (orifice diameter) of the pressure reduction portion 71 of the first communication passage 51. Thereby, even when foreign matter is mixed in the first communication passage 51 or when foreign matter is accumulated in each of the decompression unit 71 and the decompression unit 72, the second communication passage is more than the decompression unit 71 of the first communication passage 51. The possibility that the decompression unit 72 of 52 is clogged first can be reduced. Thereby, for example, when the decompression part 72 of the second communication path 52 is clogged before the decompression part 71 of the first communication path 51, the pressure of the air flowing into the first communication path 51 is directly introduced into the governor 62. In the present embodiment, it is possible to avoid a dangerous state in which excessive fuel is supplied to the burner 20 and the air ratio becomes too low, resulting in incomplete combustion and excessive CO. In addition, if the pressure reducing portion 71 of the first communication passage 51 is clogged, the pressure introduced into the governor 62 is reduced, so that the fuel supplied to the burner 20 is reduced (high air ratio is maintained). Since no flame is generated and misfire occurs, the boiler device 1 can be controlled to be on a safer side.

<Embodiment 2>
In the first embodiment, the flow rate adjusting unit 8 includes the mechanical governor 62 and mechanically adjusts the flow rate of the fuel supplied to the boiler body 2, whereas in the second embodiment, the boiler body The structure which adjusts the flow volume of the fuel supplied to 2 electronically by a control part is demonstrated. Below, only the difference with the boiler apparatus 1 which concerns on Embodiment 1 is demonstrated in detail.

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

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

  Also in the present embodiment, decompression units 71 and 72 are provided in the first communication path 51 and the second communication path 52, respectively. The decompression unit 71 is provided closer to the air passage 30 than the pressure sensor 73, and the decompression unit 72 is provided closer to the boiler body 2 than the pressure sensor 73.

  The pressure sensor 73 is electrically connected to the control unit 9. Thereby, 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 adjustment 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 adjustment valve 81 based on the opening degree adjustment information stored in the memory 10 in advance. Thereby, the regulating valve 81 is controlled to an opening degree corresponding to the differential pressure between the pressure in the air passage 30 and the pressure in the boiler body 2, and can adjust the flow rate of fuel supplied to the boiler body 2. . The opening degree adjustment information may be, for example, a table that can specify the opening degree of the adjustment valve 81 according to the differential pressure, or for specifying the opening degree of the adjustment valve 81 according to the differential pressure. An arithmetic expression may be used.

  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 thing, since a considerable pressure is lost by the punching metal, it is necessary to adopt a fan with high performance, which is expensive. On the other hand, in the second embodiment, the flow rate of combustion air can be calculated using the fixed pressure loss from the blower passage 30 to the boiler body 2 (inside the passage) without using punching metal or the like. For this reason, the cost which an air blower requires can be suppressed at least.

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

  The boiler device 1 in the above embodiment includes a fuel supply line that supplies gas and a fuel supply line that supplies oil, and either a mode that uses gas as fuel or a mode that uses oil as fuel. It may be one that can be switched and controlled.

  In the above embodiment, the orifices are 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 this as long as they can be decompressed, and may be valves or the like whose opening degree can be adjusted. Further, in the above-described embodiment, the example in which the decompression unit is provided in each of the first communication path 51 and the second communication path 52 has been described. However, the present invention is not limited to this, and each of the first communication path 51 and the second communication path 52 may not be provided with a decompression section. In addition, any one of the first communication path 51 and the second communication path 52 may be used. Only one of them (for example, the first communication path 51) may be provided with a pressure reducing unit. In this case, in the first embodiment, for example, the size of the diameter of each of the first communication path 51 and the second communication path 52 may be adjusted according to the specification or design of the boiler device 1. In form 2, the opening degree adjustment information may be adjusted according to, for example, the specification or design of the boiler device 1.

  In the second embodiment, the example in which the governor 62 is provided on the downstream side of the on-off valve 61 has been described. A valve (electromagnetic valve) for opening and closing the valve may be provided.

  The embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Boiler apparatus 1A Boiler apparatus 2 Boiler main body 3 Blower 4 Flue 5 Fuel supply line 8 Flow rate adjustment part 9 Control part 10 Memory 20 Burner 30 Blower path 51 1st communication path 52 2nd communication path 53 Branch path 61 On-off valve 62 Governor 71 Pressure reducing part 72 Pressure reducing part 73 Pressure sensor 81 Adjusting valve

Claims (6)

Boiler body,
A blower that sends air into the boiler body through a blower path;
A first communication path communicating with the air blowing path;
A second communication passage communicating with the boiler body;
A boiler device comprising: a flow rate adjusting unit that adjusts a flow rate of fuel supplied to the boiler body in accordance with a differential pressure between the first communication path and the second communication path.   The boiler device according to claim 1, wherein the first communication path is provided with a first pressure reducing unit that reduces pressure from the air passage.   The boiler device according to claim 2, wherein the second communication path is provided with a second pressure reducing unit that reduces the pressure from the boiler body.   The boiler device according to claim 3, wherein a flow path area of the second pressure reducing unit is larger than a flow path area of the first pressure reducing part. The flow rate adjusting unit adjusts the opening according to a differential pressure between the pressure reduced by the first pressure reducing unit and the pressure reduced by the second pressure reducing unit, and the pressure of the supplied fuel. Including valves,
The boiler device according to claim 3 or 4, wherein the pressure adjusting valve adjusts a flow rate of fuel supplied in accordance with an opening degree. The flow rate adjustment unit is
A flow rate adjusting valve that adjusts the flow rate of fuel to be supplied according to the opening;
A differential pressure information output unit for outputting differential pressure information for specifying a differential pressure between the first communication path and the second communication path;
The boiler apparatus in any one of Claims 1-4 containing the control part which controls the opening degree of the said flow regulating valve based on the said differential pressure information.

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