JP2010007968A - Hot water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water supply device capable of being miniaturized as a while by improving heat efficiency of a secondary heat exchanger. <P>SOLUTION: This hot water supply device 1 comprises a combustion section 2, a combustion case 3 in which a combustion gas flows, a primary heat exchanger 20 capable of heating hot water/water by heat exchange with a combustion gas flowing in the combustion case 3, an exhaust collecting section 5 disposed at a downstream side of the combustion case 3, the annular secondary heat exchanger 30 capable of heating hot water/water by heat exchange with the combustion gas flowing in the exhaust collecting section 5, and an exhausting section 6 for exhausting. The exhaust collecting section 5 has a lead-in opening 60 for introducing the combustion gas passing through the combustion case 3, a discharge opening 62 for discharging the combustion gas to the exhausting section 6, and a heat exchanger accommodating flow channel 57 accommodating the secondary heat exchanger 30, and the heat exchanger accommodating flow channel 57 circulates the combustion gas lead in from the lead-in opening 60 along the circular secondary heat exchanger 30 and distributes the same to the discharge opening 62. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hot water supply apparatus capable of heating hot water or a liquid of a heat medium, and relates to an apparatus provided with a secondary heat exchanger in addition to a primary heat exchanger.

Conventionally, a so-called latent heat recovery type hot water supply apparatus as disclosed in Patent Documents 1 and 2 below has been provided. This type of hot water supply apparatus includes a combustion means for burning fuel, a primary heat exchanger for mainly recovering sensible heat contained in the combustion gas generated therein, and a second for recovering mainly latent heat. And a secondary heat exchanger.
JP 2006-105467 A JP 2006-275367 A

In the hot water supply apparatus as disclosed in Patent Documents 1 and 2, since hot water heated by the secondary heat exchanger is sent to the primary heat exchanger, the performance of the secondary heat exchanger is related to the hot water supply efficiency of the entire apparatus. It has a big influence on. Conventional hot water supply devices have increased the heat efficiency of the secondary heat exchanger by increasing the outer diameter of the secondary heat exchanger and expanding the heat transfer area of the secondary heat exchanger.
However, in this type of hot water supply device, downsizing is desired from the viewpoint of space saving of the installation place, but when the outer diameter of the secondary heat exchanger is increased, the entire hot water supply device is increased in size. There was a problem.

  Then, this invention makes it a subject to provide the hot water supply apparatus which can improve the thermal efficiency of a secondary heat exchanger and can reduce the size of the whole apparatus.

  In order to solve the above-described problem, a hot water supply apparatus according to claim 1 is configured to exchange heat between a combustion part that burns fuel, a combustion case in which combustion gas generated by combustion in the combustion part flows, and a combustion gas that flows in the combustion case By heat exchange between the primary heat exchanger capable of heating the hot water with the exhaust gas, the exhaust gas collecting portion that is disposed downstream of the combustion case and that passes through the combustion case, and the combustion gas that flows through the exhaust gas collecting portion. An annular secondary heat exchanger that can heat the exhaust gas, and an exhaust part that exhausts the combustion gas that has passed through the exhaust gas collecting part, wherein the exhaust gas collecting part introduces the combustion gas that has passed through the combustion case An inlet that discharges combustion gas to the exhaust part, a heat exchange accommodating part that accommodates the secondary heat exchanger, and a gas introduction channel that connects the inlet and the heat exchange accommodating part The discharge port and the heat exchanger accommodating part A gas exhaust passage, and the heat exchange accommodating portion is disposed around the gas introduction passage and the gas discharge passage to accommodate the secondary heat exchanger, and The combustion gas introduced into the gas introduction channel is circulated along the annular heat exchanger and is sent from the gas discharge channel to the discharge port.

  The hot water supply apparatus of the present invention exchanges heat between the combustion gas and hot water flowing through the secondary heat exchanger by passing the combustion gas introduced into the exhaust collecting portion along the annular secondary heat exchanger. And the latent heat contained in the combustion gas can be recovered. The hot water supply apparatus of the present invention can bring combustion gas into contact with the entire secondary heat exchanger, and can effectively utilize the entire heat transfer area of the secondary heat exchanger. Therefore, the hot water supply apparatus of the present invention has high thermal efficiency in the secondary heat exchanger, and can improve the thermal efficiency of the entire apparatus without increasing the size of the secondary heat exchanger. Therefore, the hot water supply apparatus of the present invention can reduce the size of the entire apparatus.

  Moreover, the hot water supply apparatus of this invention can introduce | transduce a combustion gas into the center part of a cyclic | annular secondary heat exchanger through a gas introduction flow path, and can make a combustion gas circulate along a secondary heat exchanger. Therefore, the hot water supply apparatus of the present invention has a simple flow path configuration for sending the combustion gas to the secondary heat exchanger, and can simply configure the exhaust collecting portion.

  The hot water supply apparatus according to claim 1, wherein the exhaust collecting portion is a plate-like member that divides a space inside the tubular member into two spaces, a tubular member disposed at a substantially center in the exhaust collecting portion. A space outside the cylindrical member serves as the heat exchange accommodating portion, one of the space inside the cylindrical member serves as the gas introduction flow path, and the space inside the cylindrical member is The other may be the gas discharge channel (claim 2).

  According to a third aspect of the present invention, in the second aspect of the present invention, the introduction port and the gas introduction flow path are arranged directly below the combustion section.

  In the hot water supply apparatus of the present invention, the introduction port and the gas introduction flow path are arranged directly below the combustion section. Therefore, the hot water supply apparatus of the present invention can flow the combustion gas from the combustion part to the gas introduction passage of the exhaust collecting part without changing the traveling direction of the combustion gas. Therefore, the hot water supply apparatus of the present invention can reduce the portion where the combustion gas changes its traveling direction until the combustion gas is sent to the secondary heat exchanger, thereby reducing the ventilation resistance of the combustion gas.

  According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the hot water supplied to the secondary heat exchanger flows in a direction opposite to the flow direction of the combustion gas in the heat exchange accommodating portion. It was characterized by that.

  In the hot water supply apparatus of the present invention, the flow of hot water in the secondary heat exchanger is in a relationship of counterflow with the flow direction of the combustion gas in the heat exchange housing. Therefore, the hot water flowing through the secondary heat exchanger can efficiently exchange heat with the combustion gas flowing through the exhaust assembly.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the secondary heat exchanger includes a heat receiving pipe capable of heat exchange heating the hot water flowing in the pipe, and the heat receiving pipe is formed in a spiral shape. The hot water flowing in the heat receiving pipe circulates around the heat exchange accommodating portion a plurality of times.

  In the hot water supply apparatus of the present invention, the heat receiving pipe constituting the secondary heat exchanger is formed in a spiral shape, and the hot water flowing through the heat receiving pipe circulates around the heat exchange accommodating portion a plurality of times. Therefore, the hot water supply device of the present invention can increase the heat transfer area of the secondary heat exchanger and increase the thermal efficiency of the secondary heat exchanger by increasing the number of circulations of the heat receiving pipe.

  According to a sixth aspect of the invention, in the fifth aspect of the invention, the secondary heat exchanger includes a plurality of heat receiving tubes arranged in parallel, and the position of the inner heat receiving tube among the plurality of heat receiving tubes arranged in parallel. Is opened to form a combustion gas flow path.

  The hot water supply apparatus of the present invention forms a combustion gas flow path by opening the position of the inner heat receiving pipe among the plurality of heat receiving pipes arranged in parallel, and reduces the ventilation resistance of the combustion gas flowing through the heat exchange accommodating portion. can do.

  Moreover, the hot water supply device according to any one of the first to sixth aspects may include a neutralization device that neutralizes drain generated in the secondary heat exchanger (claim). Item 7).

  The present invention can provide a hot water supply apparatus that can improve the thermal efficiency of the secondary heat exchanger and reduce the overall size of the apparatus.

  Next, a hot water supply apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the vertical / horizontal positional relationship will be described based on a normal installation state unless otherwise specified. FIG. 1 is a front view showing an internal configuration of a hot water supply apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing an exhaust collecting portion of the hot water supply apparatus. FIG. 3 is a perspective view showing a secondary heat exchanger of the hot water supply apparatus. FIG. 4 is a perspective view showing a state in which the secondary heat exchanger is accommodated in the exhaust collecting portion.

  As shown in FIG. 1, the hot water supply device 1 is a so-called latent heat recovery type hot water supply device including a combustion section 2, a primary heat exchanger 20, and a secondary heat exchanger 30. The hot water supply device 1 includes a combustion case 3 and an exhaust collecting unit 5 below the combustion unit 2. Further, an exhaust part 6 is provided on the side of the combustion part 2. The combustion case 3 and the exhaust part 6 communicate with an exhaust collecting part 5 provided on the bottom side of the hot water supply device 1. As a result, the hot water supply apparatus 1 is formed with a space communicating from the combustion case 3 through the exhaust collecting portion 5 to the exhaust portion 6 so as to have a substantially “U” cross-sectional shape.

  The combustion unit 2 includes an air case 8, a fuel spray nozzle 10, a blower 11, a combustion cylinder 12, and the like. The combustion part 2 is comprised by what is called a reverse combustion type combustion apparatus, and can form a flame toward the downward direction. Specifically, the combustion unit 2 operates the blower 11 to introduce combustion air into the air case 8 and directs the liquid fuel supplied from a fuel supply source (not shown) downward from the fuel spray nozzle 10. Sprayed and combusted in the combustion cylinder 12.

  The combustion case 3 is disposed below the combustion unit 2 and is connected to the combustion unit 2 in an airtight manner by interposing a heat-resistant packing made of ceramic (not shown). For this reason, the combustion case 3 functions as a combustion gas passage through which the high-temperature combustion gas generated along with the combustion operation in the combustion section 2 flows downward.

  A primary heat exchanger 20 is provided at a lower end side portion of the combustion case 3. The primary heat exchanger 20 is mainly for recovering sensible heat contained in the combustion gas flowing through the combustion case 3. The primary heat exchanger 20 is configured by a so-called fin-and-tube heat exchanger. That is, the primary heat exchanger 20 has a series of bent water pipes 21, and the water pipes 21 are inserted so as to cross the combustion case 3. A large number of fins 22 are attached to the water pipe 21. The primary heat exchanger 20 can heat-heat the hot water flowing in the water pipe 21 by heat exchange with the high-temperature combustion gas flowing in the combustion case 3.

  The water pipe 21 has a primary water outlet 23 on one end side and a primary water inlet 25 on the other end side. The primary water outlet 23 is connected to a hot water supply destination such as a curan (not shown) via a pipe (not shown). On the other hand, the primary water inlet 25 is connected to a secondary heat exchanger 30 described later via a pipe 38.

  The exhaust collecting portion 5 is a box-like member disposed below the combustion case 3 and is a portion that directly communicates with the combustion case 3. The exhaust collecting portion 5 has an internal space extending in the width direction (left and right direction in FIG. 1) of the hot water supply device 1. Further, the exhaust collecting portion 5 communicates with an exhaust portion 6 disposed on the side of the combustion case 3. Therefore, the exhaust collecting part 5 functions as a part that allows the combustion gas flowing downward in the combustion case 3 to flow in and flows out the combustion gas toward the exhaust part 6. In other words, the exhaust collecting portion 5 functions as a portion for turning upward the flow direction of the combustion gas flowing downward.

  As shown in FIG. 2, the exhaust collecting portion 5 is divided into partitions 51, 52, and 53 so that the internal space becomes a gas introduction passage 55, a gas discharge passage 56, and a heat exchange accommodation passage 57 (heat exchange accommodation portion). It is partitioned. Specifically, the partition 51 (cylindrical member) is a cylindrical member disposed substantially in the center of the exhaust collecting portion 5, and the internal space of the exhaust collecting portion 5 is divided into a space inside the partition 51 and the partition. It is divided into a space outside 51. In the exhaust collecting portion 5 of the present embodiment, a gas introduction channel 55 and a gas discharge channel 56 are provided in a space inside the partition 51, and a heat exchange accommodating channel 57 is provided in a space outside the partition 51. .

  The partition 52 (plate-shaped member) is a plate-shaped member that vertically cuts the space inside the partition 51. The space inside the partition 51 is divided by the partition 52 into a space immediately below the combustion part 2 and a space directly below the exhaust part 6 described in detail later, and the space directly below the combustion part 2 is a gas introduction flow. The space immediately below the exhaust part 6 becomes the gas discharge flow path 56.

  The gas introduction channel 55 has an introduction port 60 for introducing combustion gas at a position directly below the combustion case 3. A communication port 61 that connects the gas introduction channel 55 and the heat exchange accommodation channel 57 is provided on the back side of the partition 51 that constitutes the gas introduction channel 55 and in the vicinity of the partition 52. On the other hand, the gas discharge channel 56 has a discharge port 62 for discharging combustion gas at a position directly below the exhaust unit 6. In addition, a communication port 63 that connects the gas discharge flow channel 56 and the heat exchange accommodating flow channel 57 is provided on the back side of the partition 51 constituting the gas discharge flow channel 56 and in the vicinity of the partition 52.

  The heat exchange accommodating flow channel 57 is disposed so as to surround the gas introduction flow channel 55 and the gas discharge flow channel 56 and communicates the gas introduction flow channel 55 and the gas discharge flow channel 56. The heat exchange accommodating flow channel 57 is a space formed in an annular shape so as to go around the inner space of the exhaust collecting portion 5 along the inner side surface 5 a of the exhaust collecting portion 5, and is located on the rear side of the partition 51. A region 57a, a front region 57b located on the front side of the partition 51, an introduction side turning region 57c connecting the back region 57a and the front region 57b on the introduction port 60 side, and a back region 57a and the front surface on the discharge port 62 side. It is roughly divided into a discharge side turning region 57d that connects the region 57b. Further, the heat exchanger accommodating flow channel 57 accommodates a secondary heat exchanger 30 described later.

  The partition 53 is a plate-like member that crosses the back surface region 57 a of the heat exchange accommodating flow channel 57, and is provided so as to be continuous with the partition 52. The partition 53 divides the back region of the heat exchange accommodating flow channel 57 into a space 65 communicating with the gas introduction flow channel 55 and a space 66 communicating with the gas discharge flow channel 56. The partition 53 also functions as a spacer that supports the heat receiving pipe 31 of the secondary heat exchanger 30 described later at a predetermined position and posture.

  As shown in FIG. 3, the secondary heat exchanger 30 is an annular heat exchange provided with a plurality of (in this embodiment, five) heat receiving pipes 31, a water inlet header 32, and a water outlet header 33. It is a vessel. A water inlet header 32 is connected to one end of each heat receiving pipe 31, and a water outlet header 33 is connected to the other end. The heat receiving pipe 31 is formed of a pipe having excellent heat conductivity and a smooth surface. The heat receiving tubes 31 are arranged so as to be parallel to each other at a constant interval, and are formed in a spiral shape including straight portions 31a extending straight in a predetermined direction and curved curved portions 31b alternately. As shown in FIGS. 1 and 4, most of the heat receiving pipe 31 is disposed in the heat exchange accommodating flow path 57 of the exhaust collecting portion 5, and the straight portion 31 a is disposed in the back region 57 a and the front region 57 b. The curved portion 31b is disposed in the introduction side turning area 57c and the discharge side turning area 57d. At this time, the secondary heat exchanger 30 is accommodated in the heat exchange accommodating flow path 57 in a state where the straight portions 31a of the respective heat receiving tubes 31 penetrate the partition 53 disposed in the back surface region 57a.

  As shown in FIGS. 2 and 4, a guide plate 70 is provided in the vicinity of all corners where the inner surface 5 a of the exhaust collecting portion 5 intersects so as to face the curved portion of the secondary heat exchanger 30. ing. In each guide plate 70, the combustion gas supplied to the heat exchange accommodating flow path 57 flows along the heat receiving pipe 31 of the secondary heat exchanger 30 disposed in the introduction side swivel region 57c and the discharge side swirl region 57d. The combustion gas is prevented from flowing into the corner where the inner surface 5a of the exhaust collecting portion 5 intersects.

  As shown in FIGS. 1 and 4, the water inlet side header 32 and the water outlet side header 33 are disposed outside the exhaust collecting portion 5 and on the side (left side in front view in FIGS. 1 and 4). The outflow side header 33 is disposed above and in front of the inflow side header 32. The water inlet side header 32 includes a secondary water inlet 35 connected to the water supply source 27 via the pipe 28, and the hot water supplied from the water supply source 27 can be branched into a plurality of heat receiving pipes 31. The water outlet header 33 includes a secondary water outlet 36 connected to the primary water inlet 25 of the primary heat exchanger 20 through a pipe 38 and collects hot water supplied from each heat receiving pipe 31. It can be sent to the primary heat exchanger 20.

  In addition, as shown in FIG. 3, the spacer 40 is attached to a predetermined position in the secondary heat exchanger 30 of the present embodiment so that the adjacent heat receiving tubes 31, 31 are arranged at a predetermined interval. ing. Therefore, a space for passage of combustion gas is secured between the adjacent heat receiving tubes 31 and 31. Further, by forming a predetermined interval between the adjacent heat receiving tubes 31, 31, the drain generated due to heat exchange adheres to the surface of the heat receiving tube 31, and the drain is connected between the adjacent heat receiving tubes 31, 31. Can be prevented.

  As shown in FIG. 1, a drain discharge port 41 is provided at the bottom of the exhaust collecting portion 5. The drain discharge port 41 functions as a discharge port for discharging the drain falling from the heat receiving pipe 31 of the secondary heat exchanger 30 to the outside of the exhaust collecting portion 5. Below the exhaust collecting portion 5, a neutralizing device 7 provided with a neutralizing agent such as calcium carbonate is disposed. The neutralizer 7 receives the drain discharged from the drain discharge port 41, neutralizes it, and can discharge it.

  The exhaust unit 6 communicates with the downstream side of the gas discharge channel 56 of the exhaust collecting unit 5. The exhaust part 6 is a part extending vertically upward with respect to the exhaust collecting part 5, and has a labyrinth-like fuel gas channel inside. Above the exhaust part 6, a gas exhaust part 15 for exhausting combustion gas to the outside is provided. The gas discharge part 15 has an exhaust opening 16 that is open on the front side of the combustion part 2, and an exhaust rectification member 17 is attached to the front face thereof.

  Then, operation | movement of the hot water supply apparatus 1 is demonstrated in detail. When the hot water supply device 1 detects that hot water has been supplied from the external water supply source 27 toward the secondary heat exchanger 30 by a flow sensor or the like (not shown), the combustion unit 2 starts a combustion operation. Combustion gas generated in the combustion cylinder 12 along with the combustion operation in the combustion unit 2 flows downward in the combustion case 3.

  Thereafter, the combustion gas that has passed through the combustion case 3 passes through the inlet 60 and is provided in the downstream of the combustion case 3 through the inlet 60 as shown by solid arrows in FIGS. Flow into. The combustion gas that has flowed into the gas introduction channel 55 is introduced from the communication port 61 into the space 65 of the back region 57 a of the heat exchange accommodating channel 57. The combustion gas introduced into the space 65 of the back surface region 57a of the heat exchange accommodating flow channel 57 passes through the introduction side swivel region 57c, the front surface region 57b, and the discharge side swirl region 57d of the heat exchange accommodating flow channel 57, and the back region 57a. To reach. That is, the combustion gas introduced from the gas introduction channel 55 to the heat exchange housing channel 57 circulates in the heat exchange housing channel 57 counterclockwise (counterclockwise). Thereafter, the combustion gas that has reached the back region 57 a of the heat exchange accommodating flow channel 57 is introduced into the gas discharge flow channel 56 from the communication port 63. Combustion gas introduced into the gas discharge passage 56 is sent from the discharge port 62 to the exhaust unit 6 provided above and downstream of the exhaust collecting unit 5, and is discharged from the exhaust unit 6 to the outside of the hot water supply device 1. The

  On the other hand, the hot water supplied from the water supply source 27 flows into each of a plurality (four in the illustrated state) of the heat receiving pipes 31 connected thereto via the water inlet side header 32 of the secondary heat exchanger 30. To do. The hot water flowing into each heat receiving pipe 31 gradually rises and circulates in the spiral heat receiving pipe 31 and reaches the water discharge side header 33.

  More specifically, the hot water that has flowed into the heat receiving pipe 31 from the water inlet side header 32 is sent to the back region 57a of the heat exchange accommodating flow channel 57 as shown by the dashed arrows in FIGS. The hot water sent to the back region 57a moves the back region 57a from the gas introduction channel 55 side to the gas discharge channel 56 side and reaches the discharge side turning region 57d. Thereafter, the hot water that has reached the discharge side turning area 57d turns clockwise (clockwise) around the gas discharge passage 56 and moves to the front area 57b. The hot water that has reached the front region 57b moves from the gas discharge channel 56 side to the gas introduction channel 55 side, and then moves to the introduction side turning region 57c. The hot water that has reached the introduction-side turning area 57c turns clockwise (clockwise) around the gas introduction flow path 55 and is returned to the back area 57a. The hot water returned to the back surface region 57a is sent to the water discharge side header 33 after repeating the above operation a plurality of times (approximately 6 times in the present embodiment). That is, in the hot water supply apparatus 1 of the present embodiment, the hot water supplied to the secondary heat exchanger 30 circulates the heat exchange accommodating flow channel 57 of the exhaust collecting portion 5 a plurality of times clockwise (clockwise). That is, the hot and cold water supplied to the secondary heat exchanger 30 is caused to flow in a direction opposite to the flow direction of the combustion gas in the heat exchange accommodating flow path 57. Thereafter, the hot water sent to the water discharge side header 33 is supplied to the primary heat exchanger 20 via the pipe 38.

  As described above, the flow of hot water in the heat receiving pipe 31 of the secondary heat exchanger 30 is in a counterflow relationship with the flow of the combustion gas flowing through the heat exchange accommodating flow path 57 of the exhaust assembly 5. Therefore, hot water flowing through each heat receiving pipe 31 of the secondary heat exchanger 30 efficiently exchanges heat with the combustion gas flowing through the heat exchange accommodating flow path 57 of the exhaust assembly 5.

  When heat exchange is performed in the secondary heat exchanger 30, the latent heat contained in the combustion gas flowing through the heat exchange accommodating flow path 57 of the exhaust collecting portion 5 flows through each heat receiving pipe 31 of the secondary heat exchanger 30. Collected in hot water. Along with this, moisture contained in the combustion gas is aggregated, and drain adheres to the surface of the heat receiving pipe 31 of the secondary heat exchanger 30. The drain adhering to the surface of the heat receiving pipe 31 falls from each part of the heat receiving pipe 31 to the bottom of the exhaust collecting part 5. The bottom of the exhaust collecting portion 5 is provided with a predetermined inclination, and the drained drain is flowed toward the drain discharge port 41, and the neutralization device provided below the exhaust collecting portion 5 from the drain discharge port 41. 7 is sent. The drain discharged from the drain discharge port 41 is neutralized by the neutralizer 7 and can be discharged to the outside.

  The hot water that has reached the outlet header 33 of the secondary heat exchanger 30 is sent to the primary inlet 25 of the primary heat exchanger 20 through the pipe 38. The hot water sent to the primary water inlet 25 passes through the water pipe 21 of the primary heat exchanger 20 and exchanges heat with the high-temperature combustion gas flowing in the combustion case 3. Hot water flowing through the water pipe 21 of the primary heat exchanger 20 mainly recovers sensible heat contained in the combustion gas flowing through the combustion case 3. The hot water heated by the primary heat exchanger passes through the primary water outlet 23 and is supplied to the currant or the like via a pipe or the like.

  The hot water supply device 1 according to the present embodiment allows the combustion gas introduced into the exhaust collecting portion 5 to pass along the annular secondary heat exchanger 30, so that the combustion gas and the hot water flowing through the secondary heat exchanger 30 are mixed. Heat exchange can be performed between them, and the latent heat contained in the combustion gas can be recovered. The hot water supply apparatus 1 of the present embodiment is capable of bringing the combustion gas into contact with substantially the entire surface of the secondary heat exchanger 30, and effectively uses the entire heat transfer area of the secondary heat exchanger 30. be able to. Therefore, the hot water supply device 1 of the present embodiment has high thermal efficiency in the secondary heat exchanger 30, and can improve the thermal efficiency of the entire device without increasing the size of the secondary heat exchanger 30. Therefore, the hot water supply apparatus 1 of this embodiment can reduce the size of the entire apparatus.

  Further, the hot water supply apparatus 1 of the present embodiment can introduce the combustion gas into the central portion of the annular secondary heat exchanger 30 through the gas introduction passage 55 and circulate the combustion gas along the secondary heat exchanger 30. it can. Therefore, the hot water supply device 1 of the present embodiment has a simple flow path configuration for introducing the combustion gas from the combustion case 3 to the secondary heat exchanger 30 and can simply configure the exhaust collecting portion 5.

  In the hot water supply apparatus 1 of the present embodiment, the introduction port 60 and the gas introduction passage 55 are arranged directly below the combustion unit 2. Therefore, the hot water supply device 1 can flow the combustion gas from the combustion unit 2 to the gas introduction passage 55 of the exhaust collecting unit 5 without changing the traveling direction of the combustion gas. Therefore, the hot water supply apparatus 1 of the present embodiment can reduce the portion where the combustion gas changes its traveling direction until the combustion gas is sent to the secondary heat exchanger 30 and reduce the ventilation resistance of the combustion gas. .

  In the hot water supply apparatus 1 of the present embodiment, the heat receiving pipe 31 constituting the secondary heat exchanger 30 is formed in a spiral shape, and the hot water flowing through the heat receiving pipe 31 circulates around the heat exchange accommodating flow path 57 a plurality of times. Therefore, the hot water supply device 1 of this embodiment can increase the heat transfer area of the secondary heat exchanger 30 and increase the thermal efficiency in the secondary heat exchanger 30 by increasing the number of turns of the heat receiving pipe 31. .

  In the hot water supply device 1 of the above embodiment, the combustion gas that has passed through the combustion case 3 is introduced into the exhaust collecting portion 5 via the gas introduction flow passage 55 and is discharged from the exhaust collecting portion 5 via the gas discharge flow passage 56. However, the present invention is not limited to such a configuration. For example, a configuration may be employed in which the gas inlet channel 55 and the gas outlet channel 56 are not provided in the exhaust collecting portion 5 but the inlet port 60 and the outlet port 62 are provided directly in the heat exchange accommodating channel 57. In this case, the combustion gas that has passed through the combustion case 3 is introduced from the inlet 60 into the back region 57a of the heat exchange accommodating flow path 57 of the exhaust collecting portion 5, and then circulates in the heat exchange accommodating flow path 57 to be discharged. The gas is discharged from the outlet 62 to the exhaust unit 6.

  Moreover, in the secondary heat exchanger 30 of the hot water supply apparatus 1 of the above embodiment, the plurality of heat receiving tubes 31 are arranged in parallel at a constant interval, but the present invention is not limited to such a configuration. Absent. For example, as shown in FIG. 5, the inner heat receiving pipe 31 is extracted from the plurality of heat receiving pipes 31 constituting the secondary heat exchanger 30 of the above embodiment, and the interval D between the predetermined adjacent heat receiving pipes 31 is set. The secondary heat exchanger 30a may be configured to be larger than the interval d between the other adjacent heat receiving tubes 31. By adopting this configuration, the hot water supply apparatus 1 can cause the portion from which the heat receiving pipe 31 is extracted to function as a combustion gas flow path. The portion where the heat receiving pipe 31 is extracted has a wider interval than the other portions of the heat exchange accommodating flow channel 57, and therefore the ventilation resistance is small and the combustion gas flows easily. Therefore, it is possible to rectify the flow of the combustion gas. In addition to the route described in FIG. 4, the combustion gas flowing into the heat exchange accommodating flow channel 57 from the introduction port 60 performs heat exchange while passing through the combustion gas flow channel formed in the portion where the heat receiving pipe 31 is extracted, It is sent from the discharge part 62 to the exhaust part 6 downstream.

It is a front view which shows the internal structure of the hot water supply apparatus which is one Embodiment of this invention. It is a perspective view which shows the exhaust_gas | exhaustion gathering part of the hot water supply apparatus which is one Embodiment of this invention. It is a perspective view which shows the secondary heat exchanger of the hot water supply apparatus which is one Embodiment of this invention. It is a perspective view which shows the state in which the secondary heat exchanger was accommodated in the exhaust gas collection part. It is a top view which shows the modification of a secondary heat exchanger.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot-water supply apparatus 2 Combustion part 3 Combustion case 5 Exhaust collection part 7 Neutralization apparatus 20 Primary heat exchanger 30 Secondary heat exchanger 31 Heat receiving pipe 51 Partition (tubular member)
52 Partition (plate member)
55 Gas introduction flow path 56 Gas discharge flow path 57 Heat exchange accommodation flow path (heat exchange accommodation section)
60 inlet 62 outlet

Claims (7)

A combustion section for burning fuel;
A combustion case through which combustion gas generated by combustion in the combustion section flows;
A primary heat exchanger capable of heating hot water by heat exchange with the combustion gas flowing through the combustion case;
An exhaust gas collecting portion into which combustion gas that is disposed downstream of the combustion case and passes through the combustion case flows;
An annular secondary heat exchanger capable of heating hot and cold water by heat exchange with the combustion gas flowing through the exhaust collecting part;
An exhaust part for exhausting the combustion gas that has passed through the exhaust assembly part,
The exhaust collecting part is
An inlet for introducing combustion gas that has passed through the combustion case;
An exhaust port for discharging combustion gas to the exhaust part;
A heat exchanger accommodating portion for accommodating the secondary heat exchanger;
A gas introduction flow path connecting the introduction port and the heat exchange accommodating portion;
A gas discharge flow path connecting the discharge port and the heat exchanger accommodating portion,
The heat exchange accommodating portion is disposed around the gas introduction flow path and the gas discharge flow path to accommodate the secondary heat exchanger, and the combustion gas introduced into the gas introduction flow path from the introduction port A hot water supply apparatus that is circulated along the annular heat exchanger and that is sent from the gas discharge passage to the discharge port. The exhaust collecting part is
A cylindrical member disposed substantially in the center of the exhaust collecting portion;
A plate-like member that divides the space inside the tubular member into two spaces, and
The space outside the cylindrical member serves as the heat exchange accommodating portion,
One of the space inside the cylindrical member becomes the gas introduction flow path,
The hot water supply apparatus according to claim 1, wherein the other of the space inside the cylindrical member serves as the gas discharge passage.   The hot water supply apparatus according to claim 2, wherein the introduction port and the gas introduction flow path are arranged directly below the combustion section.   The hot water supply device according to any one of claims 1 to 3, wherein the hot water supplied to the secondary heat exchanger is caused to flow in a direction opposite to a flow direction of the combustion gas in the heat exchange accommodating portion. . The secondary heat exchanger includes a heat receiving pipe capable of heat exchange heating of hot water flowing in the pipe,
The heat receiving pipe is formed in a spiral shape,
The hot water supply device according to any one of claims 1 to 4, wherein the hot water flowing through the heat receiving pipe circulates around the heat exchange accommodating portion a plurality of times. The secondary heat exchanger has a plurality of heat receiving tubes arranged in parallel,
The hot water supply apparatus according to claim 5, wherein a position of an inner heat receiving pipe among the plurality of heat receiving pipes arranged in parallel is opened to form a combustion gas flow path.   The hot water supply device according to any one of claims 1 to 6, further comprising a neutralization device for neutralizing drain generated in the secondary heat exchanger.

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