JP2015124906A - Heat exchanger and water heater equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger capable of appropriately preventing the risk that the action of heating gas such as combustion gas makes part of the heat exchanger into an overheated state to cause thermal damage.SOLUTION: Provided is a heat exchanger HE1 configured so that a first heat transfer tube arrangement section Ra (Rb1) in which three or more heat transfer tubes Ta (Tb) are aligned at generally the same height are arranged side by side to be spaced apart in a width direction, hot water being supplied first to one end heat transfer tube Ta1 (Tb1) from outside of the heat exchanger HE1 out of a pair of end heat transfer tubes Ta1 and Ta2 (Tb1 and Tb2) located on both ends in the width direction, respectively. The heat exchanger HE1 comprises an auxiliary pipe section 17a (17b) introducing the hot water supplied to one end heat transfer tube Ta1 (Tb1) and passing through the end heat transfer tube Ta1 (Tb1) to the other end heat transfer tube Ta2 (Tb2) without flowing the hot water to an intermediate heat transfer tube Ta3 (Tb3), the hot water after passing through the other end heat transfer tube Ta2 (Tb2) flowing to the intermediate heat transfer tube Ta3 (Tb3).

Description

  The present invention relates to a heat exchanger configured to recover heat from a heating gas such as a combustion gas by using a fin tube type heat transfer tube, and a hot water apparatus such as a hot water supply apparatus provided with the heat exchanger.

An example of a hot water apparatus such as a gas hot water supply apparatus is shown in FIG.
The hot water apparatus B shown in the figure includes a fin 31 and a plurality of heat transfer tubes 32 penetrating through the fin 31 in a can 30 and includes a heat exchanger HE. The combustion gas generated by the burner 5a acts on the plurality of heat transfer tubes 32, whereby hot water flowing in the plurality of heat transfer tubes 32 is heated.
In such a hot water apparatus B, a plurality of heat transfer tubes 32 are arranged in, for example, a plurality of upper and lower stages (upper and lower three stages in the figure), and hot water to be heated is placed in each of the plurality of heat transfer tubes 32. It is configured to flow sequentially. In this case, as indicated by the arrows in the figure, the hot water is typically configured to flow in a so-called arrangement order of the plurality of heat transfer tubes 32 (see, for example, Patent Document 1).
According to such a configuration, when connecting the plurality of heat transfer tubes 32 so that the hot water flows in series to the plurality of heat transfer tubes 32, except for a part, basically, the heat transfer tubes 32 adjacent to each other are connected by piping. Therefore, the piping connection structure can be simplified.

  However, the prior art still has room for improvement as described below.

  That is, paying attention to the three heat transfer tubes 32 (32a to 32c) located at the lowermost stage of the heat exchanger HE, first, water from the outside is supplied to the heat transfer tube 32a at the left end and passes through the heat transfer tube 32a. Thereafter, the hot water sequentially flows through the intermediate heat transfer tube 32b and the right end heat transfer tube 32c. In the vicinity of the leftmost heat transfer tube 32a, the combustion that proceeds from the burner 5a is caused because relatively low-temperature hot water that has not yet been sufficiently heated by the burner 5a flows through the leftmost heat transfer tube 32a. The amount of heat recovered from the gas is large, and the left side wall 30a of the can 30 can be kept from becoming too hot. On the other hand, hot water whose temperature has risen considerably through the left end and the intermediate heat transfer tubes 32a and 32b flows to the right end heat transfer tube 32c. Therefore, in the vicinity of the heat transfer tube 32c at the right end, the amount of heat recovered from the combustion gas is reduced and the temperature of the combustion gas is high compared to the vicinity of the heat transfer tube 32a at the left end. For this reason, the right side wall part 30b of the can 30 may be in an overheated state and may cause thermal damage.

Japanese Patent Laid-Open No. 10-47778

  The present invention has been conceived under the circumstances as described above, and it is appropriate that a part of the heat exchanger is overheated due to the action of a heating gas such as a combustion gas to cause thermal damage. It is an object of the present invention to provide a heat exchanger that can be easily prevented, and a hot water device including the heat exchanger.

  In order to solve the above problems, the present invention takes the following technical means.

  The heat exchanger provided by the first aspect of the present invention includes a plurality of heat transfer tubes penetrating through a plurality of plate-like fins, the plurality of heat transfer tubes and the plurality of fins therein, and a lower side. Or a can body that is set so that the heating gas flows into the inside from above, and as the arrangement structure of the plurality of heat transfer tubes, three or more heat transfer tubes arranged at substantially the same height, At least one of the side walls of the can body or another member disposed in the can body is located on both sides of the can body in the width direction of the can body in the front-rear or left-right width direction. The first heat transfer tube array portion includes a first heat transfer tube array portion, and one end heat transfer tube of the pair of end heat transfer tubes located at both ends in the width direction is outside the heat exchanger. It is a heat exchanger that is configured to receive the hot water supply from Thus, the hot water supplied to the one end heat transfer tube and passed through the end heat transfer tube does not flow to the intermediate heat transfer tube positioned between the pair of end heat transfer tubes, and is transferred to the other end heat transfer tube. An auxiliary piping section leading to the heat pipe is further provided, and the hot water after passing through the other end heat transfer pipe is configured to flow to the intermediate heat transfer pipe.

According to such a configuration, the following effects can be obtained.
Of the pair of end heat transfer tubes located at both ends of the first heat transfer tube array portion, the hot water supplied to one end heat transfer tube and passed through this end heat transfer tube does not pass through the intermediate heat transfer tube. In order to be supplied to the other end heat transfer tube, hot water that has been heated by passing through the one end heat transfer tube flows through the other end heat transfer tube. Therefore, it is possible to lower the temperature of the hot water flowing through the other end heat transfer tube as compared with the case where the hot water passing through the intermediate heat transfer tube is supplied to the other end heat transfer tube. As a result, the amount of heat recovered in the vicinity of the other end heat transfer tube is increased, and the side wall of the can body located on the side of the other end heat transfer tube or the predetermined member in the can body is heated to an abnormally high temperature. It is possible to prevent the occurrence of problems such as thermal damage due to the state.

  In the present invention, preferably, a plurality of other heat transfer tubes provided separately from the first heat transfer tube arrangement portion are arranged at intervals in the width direction, and are arranged in the first heat transfer tube arrangement portion. By being connected by piping, the apparatus further comprises a second heat transfer tube array portion through which hot water that has passed through each heat transfer tube of the first heat transfer tube array portion circulates, and the first heat transfer tube array portion Is positioned upstream of the second heat transfer tube array portion in the flow direction of the heating gas.

According to such a configuration, in addition to the first heat transfer tube array portion, the second heat transfer tube array portion is further provided, thereby increasing the total amount of heat recovered from the heating gas and improving the heat exchange efficiency. It is possible to increase. In addition to this, the following effects can be obtained.
That is, the first heat transfer tube array portion is in a state in which the temperature of hot water flowing through each heat transfer tube is lower than that of the second heat transfer tube array portion. Located upstream in the direction. For this reason, the heating gas that has entered the inside of the can of the heat exchanger is immediately and efficiently recovered by the first heat transfer tube array portion, and the temperature is lowered. Therefore, it can suppress more effectively that a can or a predetermined member in a can becomes an overheated state.

  In the present invention, preferably, the plurality of heat transfer tubes constituting the first and second heat transfer tube arrangement portions are arranged in a symmetric zigzag arrangement, and the first and second heat transfer tube arrangement portions are arranged between each other. In the pipe connection structure, the center-to-center distance P2 between the two heat transfer tubes to be connected is the same as the heat transfer tube pitch P1 of the first heat transfer tube array portion, and the heat transfer of the second heat transfer tube array portion is the same. By making the heat pipe pitch P3 larger than the heat transfer pipe pitch P1, the inclination angle α1 with respect to the horizontal of the straight line La connecting the centers of the two heat transfer pipes to be connected is less than 60 °. .

  According to such a configuration, the heat transfer tube pitch P1 of the first heat transfer tube array portion is set to a minimum pitch (for example, a size that is twice the minimum bending radius of the U-tube) that can be pipe-connected using, for example, a U-tube. ), The two heat transfer tubes to be connected to the first and second heat transfer tube arrangement portions are properly used by using the U-tube having the minimum pitch or a piping member similar thereto. Can be connected to the pipe. In addition, by setting the inclination angle α1 with respect to the horizontal of the straight line La connecting the centers of the two heat transfer tubes to be connected to less than 60 °, the first and second heat transfer tube arrangement portions in the vertical height direction are arranged. The arrangement pitch can be narrowed, and the heat exchanger can be made thinner than before (these points will become more apparent from the description of embodiments described later). In addition, since the plurality of heat transfer tubes constituting the first and second heat transfer tube arrangement portions have a symmetrical heat transfer tube arrangement, there is no significant bias in the distribution of heat recovery in the width direction. In this way, it is possible to increase the heat exchange efficiency.

  In the present invention, preferably, the plurality of heat transfer tubes constituting each of the first and second heat transfer tube arrangement portions are provided in an overlapping manner in the vertical height direction, and the first and second heat transfer tube arrangements are provided. The pipe connection between the heat transfer tube arrangement portions is performed by connecting two heat transfer tubes that are displaced in the horizontal direction and are in an oblique vertical relationship.

According to such a configuration, the following effects can be obtained.
That is, as a means for connecting the first and second heat transfer tube arrangement portions by piping, it is conceivable to connect two heat transfer tubes in an arrangement relationship that overlap each other in the vertical height direction other than the above configuration. In this case, it is difficult to make the arrangement pitch in the vertical height direction of the first and second heat transfer tube arrangement portions smaller than the minimum pitch that can be piped using, for example, a U-shaped tube. On the other hand, according to the said structure, such difficulty is eliminated, the arrangement pitch of the up-and-down height direction of the 1st and 2nd heat exchanger tube arrangement | positioning part is made smaller than the said minimum pitch, It is possible to reduce the thickness.

  In the present invention, preferably, by providing a partition member in the can body, the can body is partitioned into first and second space portions in the width direction. Each of the space portions is provided with the first heat transfer tube array portion.

  According to such a configuration, a so-called one-can two-circuit type heat exchanger is configured, and hot water using two first heat transfer tube arrangement portions disposed in each of the first and second space portions. Heating is possible. Since the amount of heat recovered from the heating gas can be increased in the vicinity of each end heat transfer tube of the two first heat transfer tube arrangement portions, the partition member is in an overheated state in addition to the side wall portion of the can body It is also possible to prevent the occurrence of the problem appropriately.

The hot water apparatus provided by the second aspect of the present invention includes the heat exchanger provided by the first aspect of the present invention.
According to such a configuration, the same effect as described above for the heat exchanger provided by the first aspect of the present invention can be obtained.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

It is a schematic front sectional view showing an example of a hot water apparatus provided with a heat exchanger (primary heat exchanger) to which the present invention is applied. It is II-II sectional drawing of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is a plane sectional view of the primary heat exchanger shown in FIG. It is principal part plane sectional drawing which shows the modification of FIG. FIG. 1 is an enlarged cross-sectional view of a main part of the hot water device. (A) is principal part explanatory drawing of FIG. 6, (b) is explanatory drawing which shows contrast. It is principal part explanatory drawing which shows the other example of this invention. It is principal part explanatory drawing which shows the other example of this invention. It is principal part explanatory drawing which shows the other example of this invention. It is principal part sectional drawing which shows the other example of this invention. It is a schematic diagram which shows an example of a prior art.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

1 to 4 show an example of a hot water apparatus to which the present invention is applied and a configuration related thereto.
As clearly shown in FIG. 1, the hot water device WH of the present embodiment includes a burner 5, a primary heat exchanger HE 1, a secondary heat exchanger HE 2, and an exterior case 90 surrounding them. This hot water apparatus WH can independently perform two hot water supply operations, ie, general hot water supply and heating hot water supply or bath hot water supply. The primary heat exchanger HE1 and the secondary heat exchanger HE2 are both One can two circuit system.
The primary heat exchanger HE1 corresponds to an example of a heat exchanger according to the present invention. However, the secondary heat exchanger HE2 does not correspond to the heat exchanger according to the present invention.

  The burner 5 is a gas burner, for example, and burns fuel gas by using combustion air sent upward from the fan 51 into the burner case 50. However, the combustion region of the burner 5 is divided into first and second combustion regions a1 and a2 that can be individually controlled for combustion drive. The upper regions of the first and second combustion regions a1 and a2 are partitioned by a partition member 52, and the combustion gas generated in each of the first and second combustion regions a1 and a2 is first and second described later. It progresses individually toward the two space portions A1, A2.

  The primary heat exchanger HE1 is for recovering sensible heat from the combustion gas traveling upward from the burner 5, and a can body 6 mounted on the burner case 50, and in the can body 6 It has a plurality of plate-like fins 2A, 2B accommodated and a plurality of straight tubular heat transfer tubes Ta, Tb penetrating through these fins 2A, 2B. The can body 6 has a substantially rectangular frame shape or cylindrical shape in plan view with an upper surface portion and a lower surface portion opened, and is made of, for example, copper. Similarly to the can 6, the heat transfer tubes Ta and Tb and the fins 2 </ b> A and 2 </ b> B are made of, for example, copper. A partition member 3 is interposed between the fins 2A and 2B, and the inside of the can body 6 is partitioned into first and second space portions A1 and A2. The first space A1 has a larger occupied area than the second space A2, but this is because the heat transfer pipe Ta arranged in the first space A1 is used for heating hot water for general hot water supply. Therefore, a hot water heating capacity larger than that on the heat transfer tube Tb side is required.

  In the first space A1, only the first heat transfer tube array portion Ra is provided as the array structure of the plurality of heat transfer tubes Ta. On the other hand, in the second space A2, first and second heat transfer tube array portions Rb1, Rb2 are provided as an array structure of the plurality of heat transfer tubes Tb.

The first heat transfer tube array portion Ra has a structure in which a plurality of heat transfer tubes Ta are arranged at substantially the same height and are arranged at intervals in the left and right width directions of the can body 6, as shown in FIG. The plurality of heat transfer tubes Ta are connected in series using the connection piping portion 12a and the auxiliary piping portion 17a that penetrate the side walls 60a and 60b of the can body 6 and are located outside the can body 6. The connection piping portion 12a is a portion using, for example, a U-shaped tube, and the heat transfer tubes Ta adjacent to each other are basically connected via the connection piping portion 12a. However, one end portions of the pair of end heat transfer tubes Ta (Ta1, Ta2) positioned at the right end and the left end of the first heat transfer tube array portion Ra are directly connected via the auxiliary piping portion 17a. The auxiliary piping part 17a is provided so as to pass, for example, the upper side of the connecting pipe part 12a in order to avoid interference with the connecting pipe part 12a.

  One end of the piping member portion 12a 'connected to the right end heat transfer tube Ta1 is a water inlet 15a. Thus, in the first heat transfer tube array portion Ra, hot water supplied to the water inlet 15a flows through the right end heat transfer tube Ta1 and then flows into the left end heat transfer tube Ta2. After that, the plurality of intermediate heat transfer tubes Ta (Ta3) positioned between the pair of end heat transfer tubes Ta1 and Ta2 sequentially flow. After hot water flows through the heat transfer pipe Ta3 located next to the right end heat transfer pipe Ta1 in the intermediate heat transfer pipe Ta3, hot water is discharged from the hot water outlet 16a, which is one end of the heat transfer pipe Ta3, to the outside. . In such a distribution process, the hot water is heated. In FIG. 1 and FIG. 6 and the like, the above-described hot water flow path is indicated by arrows (the hot water flow paths in the first and second heat transfer tube array portions Rb1 and Rb2 described later are also indicated by arrows. Shown).

  Each of the first and second heat transfer tube arrangement portions Rb1 and Rb2 has a structure in which a plurality of heat transfer tubes Tb are arranged at substantially the same height and are arranged at intervals in the left and right width directions of the can body 6 ( In the present embodiment, the number of heat transfer tubes Tb is three for the first heat transfer tube array portion Rb1 and two for the second heat transfer tube array portion Rb2. The second heat transfer tube array portion Rb2 is located above the first heat transfer tube array portion Rb1, and the plurality of heat transfer tubes Tb are arranged in a symmetrical zigzag array. The arrangement of the plurality of heat transfer tubes Tb in the upper and lower two stages makes the hot water heating capacity as high as possible while keeping the occupied area of the second space A2 relatively small, and is suitable for increasing the size of the hot water heater, for example. It is for dealing with.

  As shown in FIG. 4, the plurality of heat transfer tubes Tb pass through the side walls 60 a and 60 b of the can body 6, as in the case of the heat transfer tube Ta, and for example, a connection piping portion 12 b and auxiliary piping using a U-shaped tube They are connected in series via the part 17b. In the first heat transfer tube array portion Rb1, a pair of left and right end heat transfer tubes Tb (Tb1, Tb2) are directly connected via an auxiliary piping portion 17b. The auxiliary piping portion 17b is provided so as to pass below the connection piping portion 12b in order to avoid interference with the connection piping portion 12b. However, instead of such a configuration, for example, as shown in FIG. 5, the auxiliary piping portion 17 b is protruded from the can body 6 larger than the connecting piping portion 12 b so as to avoid interference with the connecting piping portion 12 b. (Although not shown, this point is the same for the above-described auxiliary piping portion 17a).

  One end of the connecting pipe portion 12b ′ connected to the left end heat transfer tube Tb1 is a water inlet 15b. The hot water supplied to the water inlet 15b flows through the left end heat transfer tube Tb1, then flows through the auxiliary pipe portion 17b to the right end heat transfer tube Tb2, and thereafter the intermediate heat transfer tube Tb (Tb3). Flowing into. The intermediate heat transfer tube Tb3 is connected to the right heat transfer tube Tb of the second heat transfer tube array portion Rb2 via the connection pipe portion 12b ". The left and right two heat transfer tubes of the second heat transfer tube array portion Rb2 are connected. Since the heat pipes Tb are connected via the connection pipes 12c, the hot water that has passed through the intermediate heat transfer pipes Tb3 then flows through the heat transfer pipes Tb of the second heat transfer pipe array part Rb2 and flows on the left side. After reaching the heat pipe Tb, hot water is discharged from the hot water outlet 16b, which is one end of the heat transfer pipe Tb, to the outside.

The piping connection between the first and second heat transfer tube array portions Rb1 and Rb2 is performed in a manner as shown in FIG. That is, as described above, the intermediate heat transfer tube Tb3 of the first heat transfer tube array portion Rb1 and the right heat transfer tube Tb of the second heat transfer tube array portion Rb2 are connected via the connection pipe portion 12b ". However, the distance P2 between the centers of these heat transfer tubes Tb3 and Tb is the same as the heat transfer tube pitch P1 of the first heat transfer tube array portion Rb1, and the heat transfer tube pitch P3 of the second heat transfer tube array portion Rb2 is Therefore, the inclination angle α1 with respect to the horizontal line of the straight line La connecting the centers of the heat transfer tubes Tb3 and Tb is set to be less than 60 °. The second heat transfer tube array portions Rb1 and Rb2 have a symmetrical heat transfer tube arrangement around the center line CL in the width direction, and the technical significance of such a configuration will be described later.

  As clearly shown in FIG. 1, the two first heat transfer tube arrays Ra and Rb1 are located near the lower portion in the can 6 and the center heights of the heat transfer tubes Ta and Tb are substantially the same. It is provided to become. In addition, the fin 2A has a smaller vertical width than the fin 2B, and the size of the fin 2A is reduced. However, this reduces the manufacturing cost and the overall weight of the primary heat exchanger HE1. It is preferable when trying. Although not shown in the drawings, the fins 2A and 2B have a plurality of convex portions (protrusions by cutting and raising, burring portions, etc.) in which appropriate portions of the fins 2A and 2B are partially projected. ) Is provided. These convex portions are useful for increasing the degree of contact between the fins 2A and 2B and the combustion gas and increasing the amount of heat recovery.

  The secondary heat exchanger HE2 is for recovering latent heat from the combustion gas that has passed through the primary heat exchanger HE1, and a plurality of transmissions are provided in the case 7 mounted on the primary heat exchanger HE1. The heat tubes 80 and 81 are accommodated, and the space between them is partitioned via a partition plate 74. The heat transfer tubes 80 and 81 and the case 7 are made of, for example, stainless steel so as to have corrosion resistance against the strongly acidic drain generated along with the recovery of latent heat. The plurality of heat transfer tubes 80 are formed as spiral tubes having different sizes and are arranged in an overlapping manner, and their upper and lower ends are drawn out of the case 7 to pass through a header 75a for water flow. 75b. The plurality of heat transfer tubes 81 are similar in basic form to the heat transfer tubes 80, and are formed as spiral tubes arranged in an overlapping manner, and at the upper and lower ends thereof, a water-flowing header 75c. , 75d are connected.

  As shown in FIG. 2, the combustion gas that has passed through the first space A <b> 1 of the primary heat exchanger HE <b> 1 proceeds into the case 7 from the air supply port 71 a of the bottom wall portion 70 a of the case 7, and the heat transfer tube 80. After passing between the gaps, the gas is discharged to the outside from the exhaust port 72 of the front wall 70b. Further, as shown in FIG. 3, the combustion gas that has passed through the second space A2 of the primary heat exchanger HE1 travels into the case 7 from the air supply port 71b and passes through the gap between the heat transfer tubes 81. Later, the gas is discharged from the exhaust port 72 to the outside. In such a process, latent heat is recovered from the combustion gas by the heat transfer tubes 80 and 81.

  As shown in FIG. 1, the hot water supplied from the water supply pipe 95a to the external water inlet 90a passes through the piping part 92a and the header 75b and flows to the heat transfer pipe 80 of the secondary heat exchanger HE2. Thereafter, the hot water is sent to the water inlet 15a of the primary heat exchanger HE1 via the header 75a and the pipe portion 93a, and sequentially passes through the plurality of heat transfer tubes Ta. The hot water that has passed through the plurality of heat transfer tubes Ta then reaches the external hot water outlet 91a through the piping portion 94a, and is then supplied to, for example, a kitchen or a washroom.

  On the other hand, the hot water supplied from the water supply pipe 95b to the external water inlet 90b is supplied to the header 75d via the piping portion 92b and flows through the heat transfer pipe 81 of the secondary heat exchanger HE2. Thereafter, the hot water is sent to the water inlet 15b of the primary heat exchanger HE1 via the header 75c and the pipe portion 93b, and sequentially passes through the plurality of heat transfer tubes Tb. The hot water that has passed through the plurality of heat transfer tubes Tb then reaches the external hot water outlet 91b via the piping portion 94b, and is then supplied to the hot water heater or used for hot water supply to the bath.

  Next, the operation of the hot water device WH will be described.

First, in the first heat transfer tube array portion Ra, the hot water supplied to the water inlet 15a first flows into the right end heat transfer tube Ta1 and then does not pass through the intermediate heat transfer tube Ta3, so that the auxiliary piping portion. It passes through 17a and flows to the left end heat transfer tube Ta2. For this reason, in addition to the hot water flowing through the right end heat transfer tube Ta1, the hot water flowing through the left end heat transfer tube Ta2 also becomes hot water that has not been sufficiently heated by the burner 5, and the temperature of these hot water is slightly lower. It can be. As a result, in the vicinity of each of the right and left end heat transfer tubes Ta1, Ta2, the amount of heat recovered from the combustion gas can be increased, and the combustion gas temperature in these regions can be lowered. As a result, the side wall portion 60c of the can body 6 and the partition member 3 located in the vicinity thereof are avoided from being heated to an abnormally high temperature by the high-temperature combustion gas, and thermal damage to these portions is prevented. . On the other hand, the hot water that has passed through the left end heat transfer tube Ta2 sequentially passes through the plurality of intermediate heat transfer tubes Ta3 and is sufficiently heated by the combustion gas. Therefore, there is no problem that the hot water heating capacity is lowered.

  In the first heat transfer tube array portion Rb1, the same action as described for the first heat transfer tube array portion Ra can be obtained. That is, since the hot water supplied to the water inlet 15b first flows to the left end heat transfer tube Tb1 and then passes through the auxiliary pipe portion 17b to the right end heat transfer tube Tb2, The temperature of the hot water flowing through the partial heat transfer tubes Tb1, Tb2 is a slightly lower temperature that has not been sufficiently heated by the burner 5. For this reason, the amount of heat recovered from the combustion gas in the vicinity of the two end heat transfer tubes Tb1 and Tb2 increases, and the side wall 60d of the can body 6 and the partition member 3 located in the vicinity thereof are heated to an abnormally high temperature. And thermal damage to these parts can be prevented appropriately. After passing through the right end heat transfer tube Tb2, the hot water passes through the intermediate heat transfer tube Tb3 and each heat transfer tube Tb of the second heat transfer tube array portion Rb2, and is sufficiently heated by the combustion gas. Therefore, there is no problem that the hot water heating capacity is lowered.

The structure in which the first and second heat transfer tube array portions Rb1 and Rb2 are connected to each other is as described above with reference to FIG. 7 (a). An effect is obtained.
First, the comparison of FIG. This proportionality corresponds to an example of the prior art, and the heat transfer tubes Tb2 and Tb at the right ends of the first and second heat transfer tube array portions Rb1 and Rb2 are connected to each other via a connection pipe portion 12b ". The horizontal arrangement pitch P1 of the plurality of heat transfer tubes Tb is constant everywhere, and the center-to-center distance P2 between the two heat transfer tubes Tb2 and Tb is also the same as the heat transfer tube pitch P1. For example, the minimum bending radius when bending a copper pipe having an outer diameter of 16 mm (the copper pipe can be suitably curved without causing a large damage to the copper pipe). In general, when the heat transfer tube Tb is a copper pipe having an outer diameter of 16 mm, the arrangement pitch P1 is, for example, 32 mm, and the two heat transfer tubes Tb2 and Tb. The inclination angle α2 with respect to the horizontal of the straight line Lb connecting the centers of the two is 60 °.
In order to increase the heat recovery efficiency by the plurality of heat transfer tubes Tb, it is desirable that the plurality of heat transfer tubes Tb be arranged in a symmetrical manner. In order to realize such a symmetrical arrangement in the above-described comparison, the first and second heat transfer tube arrangement portions are obtained when the arrangement pitch P1 is set to the minimum bending radius of the connection pipe portion 12b. The arrangement pitch Hb in the vertical height direction of Rb1 and Rb2 is minimized.

On the other hand, in the configuration of the present embodiment shown in FIG. 7A, the center-to-center distance P2 between the two heat transfer tubes Tb3 and Tb connected via the connection pipe portion 12b "is the first heat transfer tube arrangement. Since it is the same as the heat transfer pipe pitch P1 of the part Rb1, the connection pipe part 12b "has the same size as the connection pipe part 12b having the minimum bending radius used for the heat transfer pipe connection of the first heat transfer pipe array part Rb1. The heat transfer tubes Tb3 and Tb can be appropriately connected. On the other hand, based on the fact that the heat transfer tube pitch P3 of the second heat transfer tube array portion Rb2 is larger than the heat transfer tube pitch P1, the inclination angle of the straight line La connecting the centers of the heat transfer tubes Tb3 and Tb is less than 60 °. For this reason, the arrangement pitch Ha in the vertical height direction of the first and second heat transfer tube arrangement portions Rb1, Rb2 is smaller than the arrangement pitch Hb shown in FIG. Therefore, according to this embodiment, the overall height dimension of the primary heat exchanger HE1 can be made smaller than the proportionality, and the thickness can be reduced. In the present embodiment, the heat transfer tubes Tb of the second heat transfer tube array portion Rb2 are displaced in the horizontal direction as compared with the proportionality, but the overall arrangement of the plurality of heat transfer tubes Tb is left-right symmetric. Therefore, it is possible to prevent a large deviation in the heat recovery distribution and to prevent a problem that the heat recovery efficiency is greatly reduced.

  8 to 11 show another embodiment of the present invention. In these drawings, elements that are the same as or similar to those in the above embodiment are given the same reference numerals as in the above embodiment.

  In the embodiment shown in FIG. 8, the number of heat transfer tubes Tb in each of the first and second heat transfer tube arrangement portions Rb1 and Rb2 is larger than that in the configuration shown in FIG. For this reason, the hot water that has sequentially passed through the left and right end heat transfer tubes Tb1 and Tb2 is out of the two intermediate heat transfer tubes Tb3 than the right heat transfer tube Tb3 connected to the second heat transfer tube array Rb2. After being sent to the heat transfer tube Tb3 located on the left side, it flows into the heat transfer tube Tb3 on the right side, and hot water flows sequentially through all the heat transfer tubes Tb of the first heat transfer tube array portion Rb1. The pipe connection structure between the heat transfer tube Tb3 and the right end heat transfer tube Tb of the second heat transfer tube array portion Rb2 is the same as the structure shown in FIG. That is, since the heat transfer tube pitch P3 of the second heat transfer tube array portion Rb2 is larger than the array pipe P1, the inclination angle α1 of the straight line La connecting the centers of the heat transfer tubes Tb3 and Tb to be connected is 60 It is less than °. Therefore, the arrangement pitch Ha in the vertical height direction of the first and second heat transfer tube arrangement portions Rb1, Rb2 can be made smaller than the proportional arrangement pitch Hb shown in FIG. 7B.

In the embodiment shown in FIG. 9, the number of heat transfer tubes Tb in each of the first and second heat transfer tube array portions Rb1 and Rb2 is the same, and each of the heat transfer tubes Tb in the first heat transfer tube array portion Rb1 is the same. Immediately above, the heat transfer tubes Tb of the second heat transfer tube array portion Rb2 are provided so as to overlap each other. The two heat transfer tubes Tb3 and Tb connected by using the connection pipe portion 12b "are not heat-overlapping positions in the vertical direction, but are heat-transfer pipes in an obliquely vertical position that are displaced from each other in the horizontal direction. Accordingly, the center-to-center distance P2 between the two heat transfer tubes Tb3 and Tb is P2> P1 in relation to the heat transfer tube pitch P1 The inclination of the straight line La connecting the centers of the heat transfer tubes Tb3 and Tb. The angle α1 is less than 60 °.
In the present embodiment, the arrangement pitch Ha in the vertical height direction of the first and second heat transfer tube arrangement portions Rb1, Rb2 is Ha = P2 · sin (α1), but by reducing the inclination angle α1. It is possible to make the primary heat exchanger HE1 thinner by making the arrangement pitch Ha smaller than the arrangement pitch Hb of FIG.

  In the embodiment shown in FIG. 10, the number of heat transfer tubes in the first and second heat transfer tube arrangement portions Rb1 and Rb2 is larger than that in the embodiment shown in FIG. However, the structure in which the two heat transfer tubes Tb3 and Tb are connected via the connection pipe portion 12b "is the same as the structure in which the two heat transfer tubes Tb3 and Tb shown in Fig. 9 are connected. The vertical arrangement pitch Ha of the second heat transfer tube arrangement portions Rb1 and Rb2 can be reduced.

  As understood from these embodiments, the heat transfer tubes Tb of the first and second heat transfer tube arrangement portions Rb1 and Rb2 are arranged in a staggered arrangement, and are arranged so as to overlap in the vertical height direction. In any case, the present invention can be applied, and the arrangement pitch in the vertical direction of the first and second heat transfer tube arrangement portions Rb1 and Rb2 can be made smaller than the conventional arrangement. The number of specific heat transfer tubes in each of the first and second heat transfer tube arrangement portions Rb1 and Rb2 is not limited.

The heat exchanger HE1 of the embodiment shown in FIG. 11 is a one-can / one-circuit system, and has a configuration in which only one first heat transfer tube array portion Ra is provided in the can body 6. Of course, the second heat transfer tube array portion may be further provided. According to this embodiment, since the amount of heat recovered from the combustion gas by the right and left end heat transfer tubes Ta1, Ta2 of the first heat transfer tube array portion Ra can be increased, It is possible to suppress the left side wall portions 60c and 60d from becoming abnormally high temperature and to prevent the thermal damage of these portions. As can be understood from the present embodiment and the previous embodiment, the present invention can be applied to any case of a single can single circuit method and a single can multiple circuit method.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the heat exchanger and the hot water apparatus according to the present invention can be variously modified within the intended scope of the present invention.

  In the above-described embodiment, a heat exchanger is provided above the burner so that the combustion gas proceeds from the lower side to the upper side of the heat exchanger. It is also possible to adopt a reverse combustion system in which a heat exchanger is provided below the gas and the combustion gas advances from the upper side to the lower side. The heating gas referred to in the present invention is not limited to the combustion gas, and for example, high-temperature exhaust gas discharged from a power generation unit such as a fuel cell or a gas engine of a cogeneration system can also be used.

  In the present invention, the plurality of heat transfer tubes are not limited to be provided in one or two stages, and may be provided in three or more stages, and further include a third heat transfer tube array portion and the like. It can also be configured. Although the heat exchanger according to the present invention is suitable for sensible heat recovery, it does not matter whether it is for sensible heat recovery or latent heat recovery. The hot water device as used in the present invention means a device having a function of generating hot water, and is used for various types of hot water supply devices for general hot water supply, bath hot water supply, heating, snow melting, and the like, and hot water supply. Widely includes equipment for producing hot water.

WH water heater HE1 primary heat exchanger (heat exchanger according to the present invention)
HE2 Secondary heat exchanger A1, A2 First and second space parts Ta, Tb Heat transfer tubes Ta1, Ta2 End heat transfer tubes Tb1, Tb2 End heat transfer tubes Ta3, Tb3 Intermediate heat transfer tubes Ra First heat transfer tube array Rb1 first heat transfer tube array portion Rb2 second heat transfer tube array portion 2A, 2B fins (first and second fins)
3 partition member (separate member arranged in the can)
6 Can bodies 17a, 17b Auxiliary piping parts 60c, 60d Side wall part (can body)

Claims (6)

A plurality of heat transfer tubes penetrating through a plurality of plate-like fins;
A can body that accommodates the plurality of heat transfer tubes and the plurality of fins therein, and is set so that the heating gas flows into the inside from the lower side or the upper side,
With
As the arrangement structure of the plurality of heat transfer tubes, three or more heat transfer tubes arranged at substantially the same height are arranged at intervals in the front and rear or left and right width directions of the can body, and on both sides of the width direction. A side wall portion of the can body or another member arranged in the can body is provided with at least one first heat transfer tube array portion,
The first heat transfer tube array portion is configured such that one end heat transfer tube of the pair of end heat transfer tubes positioned at both ends in the width direction first receives hot water supply from the outside of the heat exchanger. A heat exchanger,
The hot water supplied to the one end heat transfer tube and passed through the end heat transfer tube is transferred to the other end heat transfer tube without flowing to the intermediate heat transfer tube located between the pair of end heat transfer tubes. A further auxiliary piping part is provided,
The heat exchanger is configured such that hot water after passing through the other end heat transfer tube flows to the intermediate heat transfer tube. The heat exchanger according to claim 1,
A plurality of other heat transfer tubes provided separately from the first heat transfer tube array portion are arranged at intervals in the width direction and connected to the first heat transfer tube array portion by piping. , Further comprising a second heat transfer tube array portion through which hot water that has passed through each heat transfer tube of the first heat transfer tube array portion circulates,
The first heat transfer tube array portion is a heat exchanger that is located upstream of the second heat transfer tube array portion in the flow direction of the heating gas. The heat exchanger according to claim 2,
The plurality of heat transfer tubes constituting the first and second heat transfer tube array portions are symmetric zigzag arrays,
In the pipe connection structure between the first and second heat transfer tube arrangement portions, the center-to-center distance P2 between the two heat transfer tubes to be connected is the same as the heat transfer tube pitch P1 of the first heat transfer tube arrangement portion. In addition, since the heat transfer tube pitch P3 of the second heat transfer tube array portion is larger than the heat transfer tube pitch P1, a horizontal line La connecting the centers of the two heat transfer tubes to be connected is horizontal. Is a heat exchanger whose inclination angle α1 is less than 60 °. The heat exchanger according to claim 2,
The plurality of heat transfer tubes constituting each of the first and second heat transfer tube arrangement portions are provided in an arrangement in which they overlap each other in the vertical height direction,
The pipe connection between the first and second heat transfer tube arrangement portions is performed by connecting two heat transfer tubes that are displaced in the horizontal direction and are in an oblique vertical relationship. The heat exchanger according to any one of claims 1 to 4,
By providing a partition member in the can body, the can body is partitioned into first and second space portions in the width direction,
A heat exchanger in which the first heat transfer tube array portion is provided in each of the first and second space portions. A hot water apparatus comprising the heat exchanger according to any one of claims 1 to 5.

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