JP2006284041A - Water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent discharging of strong-acid drain water without neutralized in a water heater recovering latent heat. <P>SOLUTION: This water heater is provided with a rain intrusion preventing flow channel 30 positioned at a downstream of an exhaust flow channel 29 for preventing intrusion of rain into the exhaust flow channel 29, thus the intrusion of rain which may have strong acid, from an exhaust opening 31 can be prevented, consumption of a neutralizing agent of a neutralizing means can be reduced, shortening of service life of the neutralizing means 38 can be prevented, and draining of strong-acid drain water without neutralized can be prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hot water supply apparatus that recovers latent heat of exhaust gas to improve efficiency.

  Conventionally, in this type of hot water supply apparatus, the exhaust gas that has passed through the auxiliary heat exchanger is exhausted through an exhaust passage that does not have a rain intrusion prevention structure (see, for example, Patent Document 1).

FIG. 3 shows an overall cross-sectional view of a conventional hot water supply apparatus described in the publication. As shown in FIG. 3, a main heat exchanging unit 2 is provided above the burner unit 1, and a downstream heat exchanging unit 4 is arranged downstream of the main heat exchanging unit 3 through an upward introduction channel 3 through which an exhaust gas flows. The sub-heat exchange part heat exchanger tube 5 which comprises is provided. A fan 6 is provided below the burner unit 1. A drain water receiver 7 that receives drain water generated in the auxiliary heat exchange unit 4 is provided below the auxiliary heat exchange unit 4, and an exhaust passage 8 through which exhaust gas flows upward is provided downstream of the auxiliary heat exchange unit 4, An exhaust port 9 is provided at the end. A drain water discharge channel 10 is provided starting from a portion that becomes the bottom of the drain water receiver 7, and a neutralizing means 11 is provided in the middle of the channel.
JP 2004-198065 A

  However, in the above-described conventional configuration, the exhaust passage 8 does not have a rain intrusion prevention structure. Therefore, if wind and rain are strong when the hot water supply device is not operating, rain enters the exhaust passage 8 from the exhaust port 9. It flows into the neutralization processing means 11 through the drain water discharge channel 10. By the way, the acidity of rain is increasing year by year due to the influence of NOx, SOx, etc. discharged from power plants, factories, automobiles, and the like. When such rain flows into the neutralization processing means 11, the neutralizing agent filled therein is consumed and the life of the neutralization processing means 11 is shortened. For this reason, in the hot water supply apparatus used for many years, there existed a subject which drain water is not neutralized but may be discharged | emitted from a hot water supply apparatus.

  This invention solves the said conventional subject, and it aims at providing the hot-water supply apparatus which can neutralize drain water until the lifetime of an apparatus is exhausted.

  In order to solve the above-described conventional problems, a rain intrusion prevention channel that is located downstream of the exhaust channel and prevents rain from entering the exhaust channel is provided.

  As a result, it is possible to suppress rain that is becoming more acidic from the exhaust port and consume the neutralizing agent of the neutralizing means, and prevent the deterioration of the life of the neutralizing means.

  The hot water supply apparatus of the present invention can prevent the strongly acidic drain water from being discharged without being neutralized.

  In the first aspect of the present invention, a main heat exchanging part located above the burner unit, a sub heat exchanging part located downstream of the main heat exchanging part and recovering the latent heat of the exhaust gas, and the exhaust gas flow upward. In addition, an introduction flow path for introducing exhaust gas from the main heat exchange section to the sub heat exchange section, and a sub heat exchange position that is located downstream of the introduction passage and exhaust gas flows downward and the sub heat exchange section is disposed. A flow path, an exhaust flow path positioned downstream of the auxiliary heat exchange flow path and through which combustion gas flows upward, and a downstream position of the exhaust flow path to prevent rain from entering the exhaust flow path A rain intrusion prevention channel, an exhaust port located downstream of the rain intrusion prevention channel, and a drain water outlet provided at the lowermost portion of the exhaust channel while receiving drain water generated in the auxiliary heat exchange unit Drain water receiver for leading drain water and neutralization treatment means for neutralizing acidic drain water It is equipped with a.

  Thereby, it can suppress that the rain which acidity becomes strong from an exhaust port invades, and consumes the neutralizing agent of a neutralization treatment means, and can prevent the lifetime deterioration of a neutralization treatment means. For this reason, it is not necessary to enlarge the neutralization treatment means by excessively filling the neutralizing agent of the neutralization treatment means, and the enlargement of the apparatus can be prevented. In addition, since the position of the exhaust port can be positioned on the upper part of the hot water supply device as in the conventional hot water supply device without latent heat recovery, it is formed on the pipe shaft door even when installed in the pipe shaft door of an apartment. The position of the exhaust port can be used as it is, and can be replaced with a conventional hot water supply device.

  According to a second aspect of the invention, in particular, in the first aspect of the invention, the rain intrusion prevention flow path is a substantially U-shaped flow path, the inclined upward flow path through which the exhaust gas flows obliquely upward, It is composed of an inclined descending channel that is located downstream of the channel and through which exhaust gas flows obliquely downward.

  Thereby, since the inclined descending channel becomes an ascending channel when viewed from the rain, it is possible to more reliably prevent rain from entering.

  In a third aspect of the invention, in particular in the second aspect of the invention, the end portion of the rain intrusion passage forming plate that forms the lower surface of the inclined down passage is folded upward to form a folded portion.

  Thereby, the rain which invaded rebounds in the folding | returning part, and it can prevent rain invasion more reliably.

  In the fourth aspect of the invention, particularly in the second or third aspect of the invention, the inclined ascending flow path is located above the auxiliary heat exchange flow path.

  Thereby, the space above the auxiliary heat exchange channel can be effectively used as the inclined rising channel, and the hot water supply apparatus can be reduced in size.

  According to a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, the burner unit is configured by arranging a plurality of small-capacity burner bodies in one direction and changing the number of burners in the burner body. The sub heat exchanger heat transfer tube is substantially orthogonal to the burner body arrangement direction and has a plurality of paths.

  As a result, it is possible to minimize the heat dissipation loss in the auxiliary heat exchange section heat transfer tube due to the room temperature air ejected from the burner body in the path downstream of the burner body that is not combusted at the time of small capacity, so that the thermal efficiency at the time of small capacity can be improved. . Moreover, when providing a fin in a heat exchanger tube, the number of fins can be reduced and cost can be reduced by man-hour reduction.

  In a sixth aspect of the invention, in any one of the first to fifth aspects of the invention, the auxiliary heat exchange section heat transfer tube constituting the auxiliary heat exchange section passes through the exhaust passage.

  Thereby, heat can be absorbed also in the exhaust passage, and the thermal efficiency can be further improved.

  In a seventh aspect of the invention, in any one of the first to sixth aspects of the invention, the seventh aspect of the invention further includes an endothermic suppression means for suppressing endothermic heat in the auxiliary heat exchange section heat transfer tube located in the introduction flow path.

  As a result, the endothermic suppression means located in the introduction passage hardly absorbs heat from the exhaust gas, so that strongly acidic drain water due to condensation does not occur, and even if there is no drain water receiver below, the drain unit or main heat exchange section is drained. Water can be prevented from falling and these corrosions can be prevented. Therefore, the freedom degree of the arrangement position of a sub heat exchange part heat exchanger tube becomes large, and the design freedom degree of a hot water supply apparatus can be enlarged.

  In an eighth aspect of the invention, in particular, in any one of the first to seventh aspects of the invention, the auxiliary heat exchange section heat transfer tube is composed of an inner tube made of copper and an outer tube made of stainless steel. Is formed by integrating the inner tube, the outer tube and a stainless steel fin by expanding the inner tube.

  Thereby, the sub heat exchange part heat exchanger tube which has acid resistance at low cost is realizable. Further, by using copper as the material of the inner tube, it is possible to easily perform U-bending of the tube and brazing for header connection. Further, by providing the fins, the heat transfer area can be dramatically increased and the thermal efficiency can be greatly improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is an overall cross-sectional view of a hot water supply apparatus according to a first embodiment of the present invention, and FIG. 2 is a front view of the hot water supply apparatus.

  1 and 2, the burner unit 21 is configured by arranging a plurality of small-capacity burner bodies 22 in one direction and storing them in a burner case 23. A fan 24 is attached to the lower part of the burner case 23. A main heat exchanging portion 25 is disposed above the burner unit 21. Downstream thereof, an introduction flow path 26, a secondary heat exchange flow path 28 provided with a secondary heat exchange section 27, an exhaust flow path 29, a rain entry prevention flow path 30, and an exhaust port 31 are provided in this order. The rain intrusion prevention flow path 30 is disposed above the auxiliary heat exchange flow path 28 so that the exhaust gas flows obliquely upward, and is located downstream of the gradient lift flow path 32 and the exhaust gas is obliquely downward. This is a substantially U-shaped flow path composed of an inclined descending flow path 33 that flows through the flow path. The rain intrusion prevention channel forming plate 34 forms the upper surface of the inclined ascending channel 32 and the lower surface of the inclined descending channel 33. Further, a folded portion 35 is provided by folding the end portion of the rain entry prevention flow path forming plate 34 upward. A drain water receiver 36 is provided below the auxiliary heat exchanger 27, a drain water discharge channel 37 starting from the bottom of the drain water receiver 36 is provided, and a neutralization processing means 38 is provided in the middle of the channel.

  An inner pipe 39 made of U-bending material and an outer pipe 40 made of stainless steel are provided through the introduction passage 26, the auxiliary heat exchange passage 28 and the exhaust passage 29. The outer tube 40 is shorter than the inner tube 39 to expose the inner tube 39. The inner pipe 39 and the outer pipe 40 constitute a sub heat exchange section heat transfer pipe 41. The auxiliary heat exchange section heat transfer tube 41 located in the auxiliary heat exchange channel 28 is provided with a stainless steel fin 42, and the inner tube 39 is expanded to integrate the inner tube 39, the outer tube 40, and the fin 42 with heat. Are connected to each other to constitute the auxiliary heat exchanging section 27.

  An inlet header 43 and an outlet header 44 are attached to the end of the inner pipe 39 by brazing to make a plurality of paths. The auxiliary heat exchanger heat transfer tubes 41 are arranged in a direction substantially orthogonal to the arrangement direction of the burner bodies 22. An air layer forming tube 46 that is a heat absorption suppressing means for forming the air layer 45 is disposed outside the outer tube 40 located in the introduction flow path 26. In order to regulate the thickness of the air layer 45, it is more preferable to provide a small number of inward projections on the air layer forming tube 46.

  The operation and action will be described below. The air supplied by the fan 24 and the fuel supplied by a fuel nozzle (not shown) flow into the burner body 22 to become a combustible air-fuel mixture, which is ejected from the flame port and burned. The exhaust gas flows through the main heat exchange unit 25 and absorbs the sensible heat of the exhaust gas. The exhaust gas flows upward through the introduction flow path 26. Since the air layer 45 having an excellent heat insulating effect is formed by the air layer forming tube 46 on the outer side of the auxiliary heat exchanging part heat transfer tube 41 located in the introduction flow channel 26, heat absorption does not occur in that portion, As a result, no drain water is generated due to condensation, and the exhaust gas passes as it is. Thereafter, the exhaust gas flows downward through the auxiliary heat exchange passage 28, absorbs the latent heat of the exhaust gas at the auxiliary heat exchange unit 27, and is condensed to generate drain water. The exhaust gas then flows upward through the exhaust passage 29, further absorbs latent heat at the auxiliary heat exchange section heat transfer pipe 41 located in the exhaust passage, and drain water is generated. The exhaust gas from which most of the latent heat has been absorbed flows through the inclined ascending channel 32 and the inclined descending channel 33 and is exhausted from the exhaust port 31.

  The drain water generated in the auxiliary heat exchange unit 27 falls to the lower drain water receiver 36, and the drain water generated in the auxiliary heat exchange unit heat transfer tube 41 located in the exhaust passage 29 falls below the exhaust passage 29. These are discharged from the drain water discharge channel 37. The strongly acidic drain water is neutralized by the neutralization processing means 38 and discharged to the outside of the hot water supply apparatus.

  Water to be heated flows in from the inlet header 43, branches into a plurality of paths, absorbs heat, and collects in the outlet header 44. After that, it flows into the main heat exchanging unit 25, absorbs heat and flows out of the hot water supply device, and is used for hot water supply, heating, bath, and the like. Here, the flow of the exhaust gas and the water flow of the auxiliary heat exchange section heat transfer pipe 41 are so-called opposite flows. Thereby, it is possible to absorb heat from the exhaust gas at a low temperature with high efficiency.

  When the capacity is small, the supply of fuel to the burner body 22 is partially stopped, and the air supplied by the fan 24 is supplied as it is to the burner body 22 that is not combusted, and air at normal temperature is ejected from the flame port. By the way, when the auxiliary heat exchange section heat transfer tube 41 is arranged so as to be parallel to the arrangement direction of the burner bodies 24, even if heat is absorbed by the auxiliary heat exchange section heat transfer tube 41 downstream of the burning burner body 22, no combustion occurs. Heat is radiated by the auxiliary heat exchanger heat transfer tube 41 downstream of the burner body 22. Here, by providing the auxiliary heat exchange section heat transfer tubes 41 so as to be orthogonal to the arrangement direction of the burner bodies 22 and making a plurality of paths, normal temperature water and air close to normal temperature in the paths downstream of the burner body 22 that are not combusted. The heat efficiency can be improved because no heat dissipation loss occurs.

  Here, if the hot and cold weather is strong with the hot water supply device not operating, rain may enter through the exhaust port 31. At present, the acidity of rain is increasing year by year, and when rain enters from the exhaust port 31, it falls below the exhaust passage and flows into the drain water discharge passage 37 to consume the neutralizing agent of the neutralizing means 38. There is a fear. By providing the rain intrusion prevention flow path 30 here, it is possible to prevent rain that is becoming more acidic from the exhaust port 31 and to consume the neutralizing agent of the neutralization treatment means 38, and the neutralization treatment means 38. It is possible to prevent the deterioration of the service life. For this reason, it is not necessary to enlarge the neutralization treatment means 38 by excessively filling the neutralization agent of the neutralization treatment means 38, and the enlargement of the apparatus can be prevented. Moreover, since the position of the exhaust port 31 can be positioned on the upper part of the hot water supply device as in the conventional hot water supply device without latent heat recovery, it is formed on the pipe shaft door even when installed in the pipe shaft door of an apartment. The position of the exhaust port can be used as it is, and can be replaced with a conventional hot water supply device.

  The rain intrusion prevention flow path 30 is a substantially U-shaped flow path, and the inclined ascending flow path 32 through which the exhaust gas flows obliquely upward and the exhaust gas that is located downstream of the inclined ascending flow path 32 It is composed of an inclined descending flow path 33 that flows obliquely downward. Since the inclined descending channel 33 becomes an ascending channel when viewed from the rain, it is possible to more reliably prevent rain from entering.

  In addition, since the upstream end of the rain intrusion channel forming plate 34 that forms the lower surface of the inclined descending channel is folded upward to form the folded portion 35, the intruded rain is rebounded by the folded portion 35, and the rain enters. Can be prevented more reliably.

  Further, by positioning the inclined ascending channel 32 above the sub heat exchange channel 28, the space above the sub heat exchange channel can be effectively utilized, and the hot water supply apparatus can be downsized.

  In addition, the burner unit 21 is configured by arranging a plurality of low-capacity burner bodies 22 in one direction and the number of burners 22 can be varied. A plurality of paths are made while being substantially orthogonal to the arrangement direction. Thereby, in the path downstream of the burner body 22 that is not combusted at the time of small capacity, the heat radiation loss in the auxiliary heat exchange section heat transfer pipe 41 due to room temperature air ejected from the burner body 22 can be minimized, so that the thermal efficiency at the time of small capacity Can be improved. By the way, the hot water supply apparatus generally has a dimension in the direction in which the burner bodies 22 are arranged larger than a dimension in a direction orthogonal to the arrangement. By arranging the auxiliary heat exchange section heat transfer tubes 41 so as to be orthogonal to the arrangement direction of the burner bodies 22, the number of fins 42 can be reduced, and the cost can be reduced by reducing the number of man-hours.

  Further, the auxiliary heat exchange unit heat transfer pipe 41 constituting the auxiliary heat exchange unit 27 penetrates the exhaust passage 29, so that heat can be absorbed also in the exhaust passage 29, and the thermal efficiency can be further improved.

  In addition, an air layer forming tube 46 is provided as a heat absorption suppressing means for suppressing heat absorption in the auxiliary heat exchange section heat transfer tube 41 located in the introduction flow path 26. As a result, the sub heat exchange section heat transfer tube 41 located in the introduction passage 26 is formed outside and hardly absorbs heat from the exhaust gas due to the presence of the air layer 45 having an excellent heat insulation effect, so that strongly acidic drain water is generated due to condensation. Therefore, even if there is no drain water receiver 36 below, it is possible to prevent the drain water from dropping into the burner unit 21 or the main heat exchanging portion 25, and to prevent these corrosions. Therefore, the freedom degree of the arrangement position of the sub heat exchange part heat exchanger tube 41 becomes large, and the design freedom degree of a hot water supply apparatus can be enlarged.

  Further, the auxiliary heat exchange section heat transfer tube 41 is composed of an inner tube 39 made of copper and an outer tube 40 made of stainless steel, and the auxiliary heat exchange section 27 is expanded from the inner tube 39 by expanding the inner tube 39. The outer tube 40 and the stainless steel fin 42 are integrally formed.

  Thereby, the sub heat exchange part heat exchanger tube 41 which has acid resistance at low cost is realizable. Further, by using copper as the material of the inner tube 39, it is possible to easily perform U-bending processing of the tube and brazing processing for header connection. Further, by providing the fins 42, the heat transfer area can be dramatically increased and the thermal efficiency can be greatly improved.

  The hot water supply apparatus of the present invention can be used for bath heating and heating in addition to hot water supply, and in particular, a so-called one-can three-water channel type hot-water supply apparatus having three functions of hot water supply, bath heating and heating in one can. It is most effective when used as. This is because a large capacity can can be used and the thermal efficiency when operating with a small capacity of heating can be greatly improved.

  In each of the above embodiments, gas has been described as fuel, but kerosene or coal may be used as fuel.

  In each of the above embodiments, the fluid to be heated has been described as water, but other than water, for example, a refrigerant can be heated.

  As described above, the hot water supply apparatus according to the present invention can prevent the strong acid drain water from being discharged without being neutralized, and thus can be widely applied as a latent heat recovery type heat source apparatus.

Whole sectional drawing of the hot-water supply apparatus in Embodiment 1 of this invention Front view of the water heater Overall cross-sectional view of a conventional water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Burner unit 22 Burner body 25 Main heat exchange part 26 Introduction flow path 27 Sub heat exchange part 28 Sub heat exchange flow path 29 Exhaust flow path 30 Rain intrusion prevention flow path 31 Exhaust port 32 Inclination rise flow path 33 Inclination descent flow path 34 Rain intrusion prevention flow path forming plate 35 Folding portion 36 Drain water receiver 38 Neutralization treatment means 39 Inner pipe 40 Outer pipe 41 Sub heat exchange part heat transfer pipe 46 Air layer formation pipe (endothermic suppression means)

Claims (8)

A main heat exchanging part located above the burner unit, a sub heat exchanging part located downstream of the main heat exchanging part for recovering latent heat of the exhaust gas, and the exhaust gas flowing upward and the main heat exchanging part An introduction flow path for introducing exhaust gas from the secondary heat exchange section to the secondary heat exchange section; a secondary heat exchange flow path that is located downstream of the introduction passage and through which the exhaust gas flows downward; and the secondary heat exchange section is disposed; An exhaust passage that is located downstream of the heat exchange passage and through which combustion gas flows upward, and a rain intrusion prevention passage that is located downstream of the exhaust passage and prevents rain from entering the exhaust passage; The drain water which receives the drain water generated at the downstream side of the rain intrusion prevention flow path and the sub heat exchange section and guides the drain water to the drain water discharge port provided at the lowermost part of the exhaust flow path Hot water supply provided with a receiver and neutralizing means for neutralizing acidic drain water Location. The rain intrusion prevention flow path is a substantially U-shaped flow path, and is an inclined rising flow path through which exhaust gas flows obliquely upward, and is located downstream of the inclined upward flow path and exhaust gas passes diagonally downward. The hot-water supply apparatus of Claim 1 comprised by the inclined downward flow path which flows. The hot water supply apparatus according to claim 2, wherein the end portion of the rain intrusion channel forming plate forming the lower surface of the inclined descending channel is folded upward to form a folded portion. The hot water supply apparatus according to claim 2 or 3, wherein the inclined ascending flow path is located above the auxiliary heat exchange flow path. The burner unit is configured by arranging a plurality of small-capacity burner bodies in one direction and the number of burners in the burner body can be varied, and the sub heat exchange section heat transfer tube constituting the sub heat exchange section is the burner body. The hot water supply apparatus according to any one of claims 1 to 4, wherein a plurality of paths are formed while being substantially orthogonal to the arrangement direction. The hot water supply apparatus according to any one of claims 1 to 5, wherein the auxiliary heat exchange section heat transfer tube constituting the auxiliary heat exchange section passes through the exhaust passage. The hot-water supply apparatus of any one of Claims 1-6 provided with the heat absorption suppression means which suppresses the heat absorption in the sub heat exchange part heat exchanger tube located in an introduction flow path. The auxiliary heat exchange part heat transfer tube constituting the auxiliary heat exchange part is composed of an inner pipe made of copper and an outer pipe made of stainless steel, and the auxiliary heat exchange part expands the inner pipe to expand the inner pipe. The hot-water supply device according to any one of claims 1 to 7, wherein the outer tube and a fin made of stainless steel are integrated.

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