JP4090152B2 - Combustion device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchanger that is heated by combustion of a burner and a combustion apparatus that includes an exhaust collection box that collects combustion exhaust gas heat-exchanged in the heat exchanger.
[0002]
[Prior art]
Even in such a combustion apparatus, in recent years, noise reduction has been required. However, in the conventional combustion apparatus, a cylindrical body for discharging the combustion exhaust gas in the exhaust recovery box to the outside of the apparatus is provided at the inlet. The exhaust gas is exhausted from the cylindrical body directly to the outside of the apparatus, or the cylindrical body is sound-absorbing with respect to the combustion exhaust gas. The exhaust passage is connected to the exhaust passage and discharged to the outside of the apparatus through the exhaust passage. Between the exhaust collection box and the cylindrical body, no measures are taken particularly for the sound absorption of the combustion exhaust gas. The fact is that it was not applied.
[0003]
[Problems to be solved by the invention]
By the way, since it is necessary to make the entire combustion apparatus as compact as possible, it is not possible to provide a very large sound absorbing device or the like. If the whole is made compact, the sound absorbing effect is not sufficient and the sound absorbing effect is sufficient. There is a problem that the overall size increases when trying to obtain the above.
Nonetheless, in the conventional combustion apparatus, no measures have been taken between the exhaust recovery box and the cylindrical body, particularly with respect to the sound absorption of the combustion exhaust gas, so there is room for improvement in this respect. .
[0004]
The present invention focuses on an exhaust collection box and a cylindrical body that have not conventionally contributed to the sound absorbing action, and enables a sound absorbing action on combustion exhaust gas between the exhaust collection box and the cylindrical body. Therefore, the present invention provides a combustion apparatus that can reduce the noise of the combustion apparatus without increasing the size of the entire combustion apparatus.
[0005]
[Means for Solving the Problems]
In order to achieve this object, according to the first aspect of the present invention, combustion comprising a heat exchanger heated by combustion of a burner and an exhaust recovery box for recovering combustion exhaust gas heat-exchanged in the heat exchanger. A cylindrical body that discharges the combustion exhaust gas in the exhaust recovery box to the outside, the longitudinal direction thereof is directed to a direction intersecting with the inflow direction of the combustion exhaust gas flowing into the exhaust recovery box from the heat exchanger, And, the inlet portion is provided inside the exhaust recovery box , the burner is configured such that the flame generation direction is downward, the heat exchanger is disposed below the burner, and the heat exchanger The exhaust recovery box is disposed below the exhaust body, and an exhaust passage for exhausting the combustion exhaust gas from the cylindrical body is provided, and a sound absorbing member that absorbs sound from the flowing combustion exhaust gas is provided in the exhaust passage. ing.
[0006]
That is, since the inlet part of the cylindrical body provided in the direction crossing the inflow direction of the combustion exhaust gas is located inside the exhaust recovery box, the combustion exhaust gas flowing into the exhaust recovery box from the heat exchanger Is bent and flows in a direction intersecting the inflow direction, and the sound energy is attenuated by the bending of the flow, and sound absorption to the combustion exhaust gas becomes possible.
Also, in the cylindrical body, sound absorption can be expected due to internal reflection, but the cylindrical body becomes longer by the amount the inlet of the cylindrical body is located inside the exhaust collection box. Also improves the sound absorption effect.
Further, when the combustion exhaust gas flows into the cylindrical body from the exhaust collection box, the flow area of the combustion exhaust gas is reduced. This utilizes the principle of expansion and contraction of the passage used in silencers, etc., and part of the sound that enters the exhaust collection box is reflected without being incident on the cylindrical body, which also causes sound energy. Is attenuated.
As a result, it is possible to expect an effective sound absorbing action for the combustion exhaust gas between the exhaust recovery box and the cylindrical body, which has not conventionally contributed to the sound absorbing action, and without particularly increasing the size of the entire apparatus, The noise of the device can be reduced.
According to the first aspect of the present invention, the burner is configured such that the flame generation direction is downward, the heat exchanger is disposed below the burner, and the exhaust recovery is disposed below the heat exchanger. A box is disposed, and an exhaust passage for discharging combustion exhaust gas from the cylindrical body is provided, and a sound absorbing member that absorbs sound with respect to the flowing combustion exhaust gas is provided in the exhaust passage.
That is, the flame of the burner is generated downward, the heat exchanger is located below the burner, and the exhaust recovery box is located below the heat exchanger. That is, it becomes easy to collect the drain.
And since an exhaust passage for exhausting combustion exhaust gas from the cylindrical body is provided and a sound absorbing member is also provided in the exhaust passage, sound absorption in the exhaust passage is also possible, and an effective sound absorbing action as the whole apparatus is achieved. It can be expected, and the noise of the combustion apparatus can be greatly reduced.
[0007]
According to invention of Claim 2, the said cylindrical body is protruded inside the said exhaust collection box larger than the half of the width along the longitudinal direction of the said cylindrical body of the said exhaust collection box.
[0008]
In other words, the inlet portion of the cylindrical body is located on the opposite side beyond half the width of the exhaust recovery box in the direction along the longitudinal direction of the cylindrical body. The inflowing flue gas will be bent and flow rapidly in the direction intersecting the inflow direction, and a more effective sound absorbing action can be expected, and the cylindrical body becomes longer by that amount. The sound absorbing action is also improved, and effective sound absorption is possible despite the relatively simple configuration.
As shown in the following transmission loss equation, the effect of the length of the cylindrical body is such that the longer the cylindrical body is, the higher the noise reduction effect is. Since it is used, effective silencing is possible without changing the overall size of the apparatus.
[Expression 1]
TL≈ (α−0.1) P1 / S
TL: Transmission loss (dB)
α: sound absorption coefficient of sound absorbing material P: circumference of duct (tubular body) (m)
1: Length of duct (tubular body) (m)
S: sectional area of duct (tubular body) (m ² )
[0009]
According to the invention described in claim 3, a plurality of the cylindrical bodies are provided, and the plurality of cylindrical bodies are arranged in a direction intersecting with the inflow direction of the combustion exhaust gas in a parallel or substantially parallel posture. Is provided.
[0010]
In other words, the flue gas flowing into the exhaust recovery box from the heat exchanger is bent and flows in a direction intersecting the inflow direction, and at the same time, it is divided into a plurality of flows. The synergistic effect with the energy attenuation enables more reliable sound absorption, and is advantageous in this respect because the combustion exhaust gas diversion has a relatively small pressure loss of the combustion exhaust gas.
[0011]
According to the invention described in claim 4, at least one of the exhaust recovery box and the cylindrical body is provided with a sound absorbing member that performs a sound absorbing action on the flowing combustion exhaust gas.
[0012]
Therefore, in addition to the sound absorbing action due to the bending of the combustion exhaust gas as described above, the sound absorbing action due to reflection inside the cylindrical body, or the sound absorbing action due to the split flow of the combustion exhaust gas, at least one of the exhaust collection box and the cylindrical body, Alternatively, the sound absorbing action provided by the sound absorbing members provided on both sides is also possible, so that more effective and reliable sound absorption is possible.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
An example in which the combustion apparatus according to the present invention is used in a hot water supply apparatus will be described with reference to the drawings. As shown in FIGS. 1 to 3, this hot water supply apparatus has a hot water supply section K that heats the water supplied from the water supply path 1 and supplies hot water to a hot water tap 2 a provided in the hot water supply path 2, and the operation of the hot water supply section K. And a remote control operation unit R for commanding operation information to the control unit H and the like.
[0016]
The hot water supply section K includes a gas combustion burner 3, a heat exchanger 4 for water heating heated by the burner 3, and a fan that supplies a mixture of combustion air and fuel gas to the burner 3. 5 and the like, and the burner 3 is configured such that the flame generation direction is downward.
And the heat exchanger 4 is arrange | positioned under the burner 3, and the exhaust-gas collection box 6 which collect | recovers the combustion exhaust gas after heat-exchange in the heat exchanger 4 is arrange | positioned under the heat exchanger 4, These A burner 3, a heat exchanger 4, a fan 5, an exhaust collection box 6, and the like are accommodated in the casing C.
[0017]
The exhaust recovery box 6 is provided with three cylindrical cylindrical bodies 8 for introducing the combustion exhaust gas from the exhaust recovery box 6 into the sound absorbing portion 7 and discharging it to the outside of the casing C. Three cylindrical bodies 8 intersect in the front-rear direction of the hot water supply apparatus, that is, in a state in which the longitudinal direction is substantially orthogonal to the inflow direction of the combustion exhaust gas flowing into the exhaust recovery box 6 from the heat exchanger 4. Are arranged side by side in a posture parallel to or substantially parallel to a horizontal direction perpendicular to the inflow direction of the combustion exhaust gas.
The inlet portion 8a of each cylindrical body 8 protrudes into the exhaust recovery box 6 larger than the lateral width of the exhaust recovery box 6, that is, half of the width of the exhaust recovery box 6 on the side along the longitudinal direction of the cylindrical body 8. Thus, for example, it is provided so as to protrude about 3/4 with respect to the lateral width L of the exhaust collection box 6.
[0018]
Therefore, the flue gas flowing into the exhaust recovery box 6 from the heat exchanger 4 is bent in a direction crossing the inflow direction, and at the same time, it is divided into three flows and flows. The energy of the sound is attenuated by the diversion, and sound absorption with respect to the combustion exhaust gas becomes possible.
Further, in the three cylindrical bodies 8, a sound absorbing action can be expected by internal reflection, and the cylindrical body 8 is a relatively long one protruding into the exhaust collection box 6. Effective sound absorbing action can be expected.
[0019]
The sound absorbing portion 7 has a structure in which glass wool G as a sound absorbing member that absorbs sound is generated on the inner surface of the combustion exhaust gas, and is disposed over substantially the entire length in the vertical direction along the inner surface of the rear wall of the casing C. It is installed.
Three cylindrical bodies 8 are connected to each other at locations slightly above the lower end of the sound absorbing portion 7, and glass wool as a sound absorbing member is provided on the inner surface of the sound absorbing portion 7. One exhaust cylinder 9 with G attached is connected in communication and extended to the front side of the casing C. Combustion exhaust gas is discharged from the front side of the casing C to the outside from an exhaust top 9a provided at the extended end of the casing. It is configured to discharge.
That is, the sound absorbing portion 7 and the exhaust cylinder 9 form an exhaust path for discharging the combustion exhaust gas from the cylindrical body 8 to the outside of the casing C.
[0020]
In this way, by arranging the sound absorbing portion 7 that forms the exhaust passage along the inner surface of the rear wall of the casing C over substantially the entire length in the vertical direction, the length of the sound absorbing portion 7 is increased and effective sound absorption is achieved. In addition, it can be stored in the casing C in a good manner.
Furthermore, since the glass wool G is affixed also to the inner surface of the exhaust tube 9 connected to the sound absorbing portion 7, the sound is also absorbed in the exhaust tube 9.
[0021]
The bottom surface of the exhaust recovery box 6 is configured as a condensate falling from the heat exchanger 4, that is, a drain recovery unit 10 that receives and recovers the drain, and the recovered drain is neutralized by the neutralizer 12. After being processed, it is configured to be discharged to the outside through the drainage channel 11.
And the glass wool G as a sound-absorbing member which has a sound-absorbing action with respect to the flowing combustion exhaust gas is affixed also to the inner periphery of the exhaust collection box 6.
[0022]
A fuel supply path 13 for supplying fuel gas is connected to the fan 5, and as the air flow rate of the fan 5 increases due to the suction action of the fan 5, a larger amount of fuel gas is sucked and mixed with combustion air. The air-fuel mixture is supplied to the burner 3.
The fuel supply path 13 is provided with an electromagnetically operated safety valve 14 and a fuel regulating valve 15 for intermittently supplying the fuel gas from the upstream side in the fuel gas supply direction. Are provided with an igniter 17 for performing an ignition operation on the burner 3 and a frame rod 18 for detecting whether or not the burner 3 is ignited.
[0023]
The heat exchanger 2 is connected to the water supply passage 1 and the hot water supply passage 2 described above, and the water supply passage 1 is supplied through the water supply amount sensor 19 for detecting the amount of water supplied to the heat exchanger 4 and the water supply passage 1. A hot water supply temperature thermistor 20 is provided for detecting the temperature of the hot water, and the hot water supply passage 2 is provided with a hot water supply temperature thermistor 21 for detecting the temperature of the hot water heated by the heat exchanger 4.
The remote control unit R also has an operation switch 22 for instructing start and stop of operation of the hot water supply unit K, an operation lamp 23 for indicating that the operation is in progress, and a combustion lamp for indicating that the burner 3 is in combustion. 24, a temperature setting switch 25 for setting a target temperature for hot water supply, a display unit 26 for displaying the target temperature, and the like.
[0024]
The control unit H includes a microcomputer, and the temperature of the hot water supplied from the hot water tap 2a becomes the target hot water temperature set by the temperature setting switch 25 based on an operation command from the remote control operation unit R. Thus, the hot water supply unit K is configured to be controlled.
That is, when the water flow amount detected by the water flow amount sensor 19 with the opening operation of the hot water tap 2a exceeds the set water amount in the state set to the operation state with the ON operation of the operation switch 22, the fan 5 The ventilation operation is started, the safety valve 14 and the fuel adjustment valve 15 are opened, the ignition operation to the burner 3 is performed by the igniter 17, and the ignition to the burner 3 is confirmed by the frame rod 18.
[0025]
Thereafter, the hot water supply thermistor 20, the hot water supply temperature thermistor 21, and the detection information from the water flow rate sensor 19 and the information on the target temperature for hot water set by the temperature setting switch 25 are supplied from the hot water tap 2 a. The amount of gas required to make the temperature of the hot water the target temperature for hot water is calculated, the fuel adjustment valve 15 is adjusted so that the calculated gas amount is reached, and the air flow rate of the fan 5 is also adjusted to feed forward control. Execute.
In addition to this feedforward control, feedback control for finely adjusting the fuel adjustment valve 15 and the fan 5 is also executed based on the deviation between the temperature detected by the hot water temperature thermistor 21 and the target temperature for hot water supply, and the hot water tap 2a. So that the temperature of hot water supplied from the water reaches the target temperature for hot water.
[0026]
[Another embodiment ]
[0029]
( 1 ) In the embodiments described so far, an example in which three cylindrical cylindrical bodies 8 are provided for the exhaust recovery box 6 has been shown. However, the number of the cylindrical bodies 8 provided in the exhaust recovery box 6 is three. It is not limited to a book, and can be four or more or two or less depending on the amount of flowing flue gas, etc., and it is configured in a cylinder other than a cylinder, for example, a rectangular cylinder. You can also. The direction of the cylindrical body 8 may also intersect with the inflow direction of the combustion exhaust gas flowing into the exhaust recovery box 6 from the heat exchanger 4 and is necessarily intersected with the inflow direction of the combustion exhaust gas. There is no need.
Furthermore, although the example which made the inlet part 8a of the cylindrical body 8 protrude about 3/4 inside with respect to the lateral width L of the exhaust collection box 6 was shown, about the amount of protrusion, according to the quantity of combustion exhaust gas, etc. It can be changed, and can be reduced to 1/2 or less with respect to the lateral width L of the exhaust collection box 6.
[0030]
( 2 ) Although glass wool was shown as an example of the sound absorbing member in the previous embodiment, ceramic wool or the like can be used instead of glass wool.
Further, the sound absorbing portion 7 is configured such that a plurality of bent passages are interposed in the flow path of the combustion exhaust gas, and the sound absorbing portion 7 is configured to absorb sound by changing the flow direction of the combustion exhaust gas in the bent passage. 7, and the sound absorbing portion 7 can be configured by a combination of a plurality of bent passages and a sound absorbing member.
As for the arrangement of the sound absorbing portion 7, various arrangements can be made along the inner surface of the front wall or the lateral wall of the casing C in addition to the vertical arrangement along the inner surface of the rear wall of the casing C as in the previous embodiment. It can also be arranged in a form.
[0031]
( 3 ) The combustion apparatus by this invention can be used for various apparatuses, such as a heating apparatus, besides using it for a hot-water supply apparatus like the previous embodiment.
[Brief description of the drawings]
1 is an overall schematic configuration diagram of a hot water supply device. FIG. 2 is an exploded perspective view of the hot water supply device. FIG. 3 is a longitudinal side view of the hot water supply device .
3 Burner 4 Heat exchanger 6 Exhaust collection box 7, 9 Exhaust path 8 Tubular body 8a Cylindrical inlet C casing G Sound absorbing member L Exhaust collection box width

Claims (4)

A combustion apparatus comprising a heat exchanger heated by combustion of a burner and an exhaust recovery box for recovering combustion exhaust gas heat-exchanged in the heat exchanger,
The cylindrical body for discharging the combustion exhaust gas in the exhaust recovery box to the outside has its longitudinal direction oriented in a direction intersecting with the inflow direction of the combustion exhaust gas flowing into the exhaust recovery box from the heat exchanger, and its inlet portion Is located inside the exhaust collection box ,
The burner is configured such that the flame generation direction is downward, the heat exchanger is disposed below the burner, and the exhaust recovery box is disposed below the heat exchanger,
A combustion apparatus in which an exhaust passage for discharging combustion exhaust gas from the cylindrical body is provided, and in the exhaust passage, a sound absorbing member is provided that absorbs sound from flowing combustion exhaust gas .   2. The combustion apparatus according to claim 1, wherein the cylindrical body protrudes into the exhaust recovery box to be larger than a half of a width of the exhaust recovery box along a longitudinal direction of the cylindrical body.   The said cylindrical body is provided with two or more, The several cylindrical body is arranged in the direction which cross | intersects the said inflow direction of combustion exhaust gas in the parallel or substantially parallel attitude | position. Combustion equipment.   The combustion device according to any one of claims 1 to 3, wherein a sound absorbing member that absorbs sound from flowing combustion exhaust gas is provided in at least one of the exhaust recovery box and the cylindrical body.

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