JP2007163039A - Hot water supply heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water supply heater capable of further enhancing heat efficiency by effectively and sufficiently recovering latent heat that is left uncollected in combustion exhaust gas after the gas has been passed through a heating second heat exchanger. <P>SOLUTION: Division plates 85, 86 between an upper case 83 having a hot-water supply side secondary heat exchanger 81 built in and a lower case 84 having a heating side secondary heat exchanger 82 built in are arranged in a staggered manner to form a gap 87. The combustion exhaust gas flowing out of the heating side primary heat exchanger 52 is allowed to flow into the lower case from a rear opening 49 and latent heat is recovered by heat exchange with low-temperature water in the heating side secondary heat exchanger. Thereafter, the combustion exhaust gas on the heating side is allowed to flow into the upper case from the gap 87 and the latent heat left uncollected on the heating side is sufficiently recovered from the combustion exhaust gas by heat exchange with water entering the hot-water supply side secondary heat exchanger. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a hot water heater provided with two cans for hot water supply and heating and configured in a two-can two-circuit or a two-can three-circuit, comprising a combustion burner, a primary heat exchanger, and a secondary heat exchange Each of the above-mentioned two can bodies is provided with a combination of water, the primary heat exchanger absorbs the sensible heat of the combustion exhaust gas, and the passing water is mainly heated, and the secondary heat exchanger passes through the primary heat exchanger. Condensation type hot water heaters that absorb and recover latent heat from combustion exhaust gas and preheat the passing water, especially in the technology that can improve the efficiency of latent heat recovery by focusing on the characteristics of hot water and heating It is concerned.

  In a conventional hot water supply / heater configured as a condensing type with two cans and two circuits, for example, as shown in FIG. The primary heat exchangers 320 and 520 are disposed on the upstream side of the combustion exhaust gas, and the secondary heat exchangers 330 and 530 are disposed on the downstream side, respectively, while hot water to be heated is first placed in the secondary heat exchangers 330 and 530. After passing through and preheating, it is passed through the primary heat exchangers 320 and 520 for main heating. The combustion exhaust gas generated by the hot water supply side combustion burner 310 in the hot water supply can 200 passes through the hot water supply side primary heat exchanger 320 and then passes through the hot water supply side secondary heat exchanger 330 and is discharged to the outside. On the other hand, flue gas generated by the combustion of the heating-side combustion burner 510 in the heating can 400 also passes through the heating-side primary heat exchanger 520 and then passes through the heating-side secondary heat exchanger 530 and is discharged to the outside. It is like that. That is, the combustion exhaust gas generated in each of the hot water supply can body 200 and the heating can body 400 is discharged to the outside as it is after the heat is separately consumed in each of the hot water supply can body 200 and 400 for heating. It has become. However, when discharging outside, the combustion exhaust gas after passing through the hot water supply side secondary heat exchanger 330 and the combustion exhaust gas after passing through the heating side secondary heat exchanger 530 are each subjected to secondary heat exchange. The gas is collected by the collective exhaust pipe 100 on the downstream side of the vessels 330 and 530 and then discharged to the outside.

  In addition, a hot water supply secondary heat exchanger and a heating secondary heat exchanger, each of which is composed of a multi-tube heat exchanger, are arranged vertically and integrated, and then a hot water supply can and a heating can Also proposed is a structure that is connected so as to straddle (for example, proposed in Patent Document 1 or Japanese Patent Application No. 2005-200950, which is a prior application of the present applicant).

Japanese Patent Laid-Open No. 2005-274043

  However, in the above-described hot water heater configured as a condensing type with two cans and two circuits, the recovery of latent heat from the flue gas in the secondary heat exchanger for heating is extremely insufficient, and latent heat remains unrecovered. As a result, the situation in which further increase in thermal efficiency is hindered is caused. That is, the recovery efficiency of latent heat depends on the temperature difference between the combustion exhaust gas having latent heat and the hot water preheated by the absorption of the latent heat. If the temperature difference is small, the recovery efficiency of latent heat is lowered and the latent heat is not yet increased. Since the recovered combustion exhaust gas is discharged to the outside, the recovery of latent heat is insufficient particularly on the side of the secondary heat exchanger for heating. For example, on the side of the heating can body, the low temperature water (for example, 60 ° C.) after being radiated from the heating terminal is returned to the heating secondary heat exchanger and heated from the heating primary heat exchanger. While water (for example, 80 ° C.) is circulated and supplied to the heating terminal, there is a remarkable difference in characteristics from a secondary heat exchanger for hot water supply in which water of about 20 ° C. is usually introduced. For this reason, even if the combustion exhaust gas temperature flowing to the heating secondary heat exchanger after passing through the heating primary heat exchanger is, for example, 70 to 80 ° C., water enters the heating secondary heat exchanger. Since there is not much temperature difference from the returned warm water, the latent heat recovery from the combustion exhaust gas is insufficient compared to the case of the secondary heat exchanger for hot water supply, and the latent heat recovery is still insufficient and the temperature is relatively high. Combustion exhaust gas will be discharged outside.

  Such a situation is caused by the fact that the flue gas discharged from each secondary heat exchanger is gathered by the collective exhaust pipe, or both the secondary heat exchangers are integrated as in the conventional hot water heater described above. Even if the structure is adopted, the combustion exhaust gas after passing through the secondary heat exchanger for heating is still discharged to the outside as it is, and the above inconvenience remains as it is.

  The present invention has been made in view of such circumstances, and an object of the present invention is to effectively utilize latent heat remaining unrecovered in the combustion exhaust gas after passing through the heating secondary heat exchanger. An object of the present invention is to provide a hot water heater that can be sufficiently recovered to further increase the thermal efficiency.

  In order to achieve the above object, according to the present invention, even if the combustion exhaust gas is generated by the combustion operation of the heating circuit and the latent heat is recovered by the secondary heat exchanger on the heating circuit side, the secondary heat on the hot water supply circuit side is further increased. By supplying to the exchanger side, the latent heat remaining unrecovered is sufficiently recovered.

  Specifically, a hot water supply circuit and a hot water circulation type heating circuit are each intended for a hot water heater equipped with a secondary heat exchanger for recovering latent heat, and combustion exhaust gas generated by the combustion operation of the heating circuit is heated. A communication passage is provided for communicating between the secondary heat exchangers so as to be supplied to the secondary heat exchanger on the hot water supply circuit side after passing through the secondary heat exchanger on the circuit side (Claim 1). .

  In the case of the present invention, although the latent heat is recovered by the secondary heat exchanger on the heating circuit side, the combustion exhaust gas in which the latent heat recovery is insufficient and unrecovered latent heat remains passes through the communication path to the secondary water source on the hot water supply circuit side. Since the heat is supplied to the heat exchanger, it is possible to sufficiently recover the latent heat from the combustion exhaust gas by heat exchange with the cold incoming water passed through the secondary heat exchanger on the hot water supply circuit side. As a result, more sufficient latent heat recovery can be achieved from the combustion exhaust gas on the heating side, which has been discharged to the outside as it is in the prior art, thereby further improving the efficiency.

  In the present invention, the hot water supply circuit and the heating circuit are configured in two cans and two circuits so that the combustion operation can be performed independently of each other, and the secondary heat exchanger on the hot water supply circuit side and the secondary heat exchanger on the heating circuit side Are arranged at respective positions in the vertical direction so as to be integrated in a state where the space is partitioned, and a communication path may be provided through the partition (claim 2). Further, the hot water supply circuit and the heating circuit are configured in two cans and two circuits so that the combustion operation can be performed independently of each other, and the secondary heat exchanger on the hot water supply circuit side and the secondary heat exchanger on the heating circuit side are mutually connected. While providing independently, the installation space of both the secondary heat exchangers can be connected to each other via a communication path (Claim 3). As a result, it is possible to provide a communication path regardless of whether the secondary heat exchangers on the hot water supply circuit side and the heating circuit side are arranged integrally or separately, and the high efficiency of the above-described thermal efficiency. Is achieved.

  Further, the communication passage is directed toward a portion corresponding to the downstream side when the combustion exhaust gas generated by the combustion operation of the hot water supply circuit is supplied toward the secondary heat exchanger on the hot water supply circuit side, and It can also arrange so that the combustion exhaust gas produced by combustion operation may be supplied. By doing so, the temperature difference between the combustion exhaust gas on the heating circuit side supplied through the communication path and the water entering the secondary heat exchanger on the hot water supply circuit side, which is a medium that absorbs latent heat, is further increased. Thus, the efficiency of latent heat recovery can be further enhanced.

  As described above, according to any one of the hot water heaters according to claims 1 to 4, although the latent heat recovery is temporarily performed by the secondary heat exchanger on the heating circuit side, the latent heat recovery is insufficient. In the combustion exhaust gas in which the unrecovered latent heat remains, the latent heat can be sufficiently recovered by heat exchange with the cold incoming water passed through the secondary heat exchanger on the hot water supply circuit side. Further efficiency improvement can be achieved.

  In particular, according to claim 2 or claim 3, whether the secondary heat exchangers on the hot water supply circuit side and the heating circuit side are arranged integrally or separately, the communication path is provided in either case. It is possible to increase the thermal efficiency.

  According to claim 4, the temperature difference between the combustion exhaust gas on the heating circuit side supplied through the communication path and the water entering the secondary heat exchanger on the hot water supply circuit side, which is a medium that absorbs latent heat, is Therefore, the efficiency of latent heat recovery can be further increased.

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

<First Embodiment>
FIG. 1 shows a principle schematic diagram of a hot water heater according to a first embodiment of the present invention. This hot water heater is composed of a hot water supply circuit 3 having a hot water supply can body 2 and a heating circuit 5 having a heating can body 4 into two cans and two circuits. In other words, the hot water supply circuit 3 and the heating circuit 5 are configured to receive combustion heating in the cans 2 and 4 independent of each other. Moreover, each of the hot water supply circuit 3 and the heating circuit 5 is configured as a condensing type provided with primary heat exchangers 32 and 52 and secondary heat exchangers 33 and 53 as described later.

  The hot water can body 2 includes a combustion case portion 21 having a hot water supply side combustion burner 31, a primary heat exchange case portion 22 having a hot water supply side primary heat exchanger 32, and a hot water supply side secondary heat exchanger 33. Is basically constructed by assembling a secondary heat exchanging case portion 23 having a built-in air and an exhaust cylinder portion 24. The hot water supply side combustion burner 31 is combusted by receiving supply of fuel (for example, fuel gas) and supply of combustion air from a blower fan 34 connected to the lower side of the combustion case portion 21. . When the hot water supply side combustion burner 31 is combusted, the generated flue gas passes through the interiors of the hot water supply side primary heat exchange case portion 22 and the secondary heat exchange case portion 23 in order, and then passes through the exhaust tube portion 24. In this case, sensible heat is absorbed by heat exchange with the primary heat exchanger 32, and latent heat is absorbed by heat exchange with the secondary heat exchanger 33. . The primary heat exchanger 32 is composed of, for example, a fin-and-tube type, and the secondary heat exchanger 33 is composed of, for example, a multi-tube type. The inlet 331 of the secondary heat exchanger 33 is connected to the downstream end of the water inlet 35, the outlet 332 is connected to the inlet 321 of the primary heat exchanger 32, and the outlet 322 is the upstream end of the hot water outlet 36. It is connected to the. In the hot water supply circuit 3, water is supplied from a water supply pipe (not shown) such as a water pipe to the upstream end side of the water inlet 35, and this is introduced into the secondary heat exchanger 33 from the inlet 331 and preheated. After that, the hot water that has been made to enter the primary heat exchanger 32 through the outlet 332 and the inlet 321 and heated by heat exchange heating is discharged from the outlet 322 to the hot water outlet 36, and the hot water outlet 36 and the figure connected to this. Hot water is supplied to a hot water tap or the like through an external hot water supply pipe.

  On the other hand, the heating can body 4 also has substantially the same configuration as the hot water supply can body 2. That is, the heating can body 4 includes a combustion case part 41 having a heating side combustion burner 51 therein, a primary heat exchange case part 42 having a heating side primary heat exchanger 52, and a heating side secondary heat exchanger. A secondary heat exchange case 43 having a built-in 53 is assembled to form a basic configuration. The heating-side combustion burner 51 is combusted in response to the supply of the fuel and the supply of combustion air from the blower fan 54 connected to the lower side of the combustion case 41. When the heating-side combustion burner 51 is combusted, the generated flue gas passes through each of the heating-side primary heat exchange case portion 42 and the secondary heat exchange case portion 43 in order, and then hot water is supplied through the communication passage 6. Is supplied into the secondary heat exchange case portion 23, and is discharged from the exhaust tube portion 24 through the secondary heat exchange case portion 23 to the outside. Thereby, sensible heat is absorbed by heat exchange with the primary heat exchanger 52, latent heat is absorbed by heat exchange with the secondary heat exchanger 53, and further heat exchange with the secondary heat exchanger 33 on the hot water supply side. Thus, unrecovered latent heat is absorbed. The primary heat exchanger 52 is composed of, for example, a fin and tube type, and the secondary heat exchanger 53 is composed of, for example, a multi-tube type. After the downstream end of the return path 55 is connected to the inlet 531 of the secondary heat exchanger 53, heat is radiated through one or more heating terminals 7 through the return path 55 (only one is shown in FIG. 1). The low-temperature water is returned to the secondary heat exchanger 53. The outlet 532 of the secondary heat exchanger 53 is connected to the inlet 521 of the primary heat exchanger 52, and the outlet 522 of the primary heat exchanger 52 is connected to the upstream end of the outgoing path 56 extending to the heating terminal 7. Yes. As a result, the low-temperature water preheated by the secondary heat exchanger 53 flows into the primary heat exchanger 52, and rises to a predetermined temperature required as a heat source for heating by heat exchange heating in the primary heat exchanger 52. The water is heated to become high-temperature water, and this high-temperature water is supplied to the heating terminal 7 through the outgoing path 56. Circulation supply between the heating terminal 7 and the heating can 4 through the forward path 56 and the return path 55 is realized by the operation of the circulation pump 57.

  Based on FIG. 2 which shows the example which made the fundamental structure of FIG. 1 into a concrete shape and structure about said secondary heat exchange case parts 23 and 43, and the communication path 6 etc. which connect and connect both. This will be specifically described. In the hot water supply can body 2, the primary heat exchange case portion 22 and the secondary heat exchange case portion 23 are connected via a collective case portion 25 for collecting and flowing the combustion exhaust gas. Also in the heating can 4, the primary heat exchange case part 42 and the secondary heat exchange case part 43 are connected via a similar collective case part 45. Each of the collecting case portions 25 and 45 collects and collects the flue gas after passing through the primary heat exchangers 32 and 52 (see FIG. 1) covering the upper surface openings of the primary heat exchange case portions 22 and 42. The combustion exhaust gas is guided to the rear side of each can body 2, 4 and then introduced into the respective secondary heat exchange case parts 23, 43 through the rear openings 26, 46. And the communicating path 6 which extends across the front side position across the front opening 27 of the hot water supply side secondary heat exchange case part 23 and the front opening 47 of the heating side secondary heat exchange case part 43 is formed. Combustion exhaust gas that has flowed forward in the side secondary heat exchange case portion 43 flows from the front opening 47 to the front side in the hot water supply side secondary heat exchange case portion 23 through the communication passage 6 and the front opening 27. . An exhaust tube 24 protrudes forward and is formed at the front upper side position of the hot water supply side secondary heat exchange case portion 23, and the combustion exhaust gas flowing into the hot water supply side secondary heat exchange case portion 23 from the rear opening 26, The combustion exhaust gas flowing in from the front opening 27 is discharged from the exhaust cylinder 24 to the outside. Here, in the hot water supply side secondary heat exchange case portion 23, the combustion exhaust gas from the hot water supply side primary heat exchange case portion 22 flows from the rear opening 26, and this combustion exhaust gas is forward in the front of the exhaust cylinder 24. Will flow. That is, the front side of the hot water supply side secondary heat exchange case part 23 into which the combustion exhaust gas from the heating side secondary heat exchange case part 43 flows is the hot water supply side secondary heat exchange case part 23 or the secondary heat exchanger 33. Corresponds to the downstream side. The exhaust cylinder 24 may be protruded upward as indicated by reference numeral 24a in addition to protruding forward.

  3A is a cross-sectional explanatory view taken along line AA in FIG. 2, FIG. 3B is a cross-sectional explanatory view taken along line BB in FIG. 2, and FIG. The structure explanatory drawing of both the secondary heat exchangers 33 and 53 of the hot_water | molten_metal supply side and heating side is shown. The hot water supply side secondary heat exchanger 33 is composed of an inlet side header 333 communicating with the inlet 331, an outlet side header 334 communicating with the outlet 332, and a return header 335. 33a and 33b are connected and connected in communication. The incoming water from the inlet 331 is divided by the inlet header 333 into the forward side thin tube group 33a composed of a plurality of thin tubes to reach the return header 335, and once merged at the return header 335, it is diverted again to the return side thin tube group 33b. It reaches the outlet header 334. Then, they are merged at the outlet header 334 and sent to the primary heat exchanger 32 through the outlet 332. The incoming water is preheated by exchanging heat with the combustion exhaust gas flowing in the secondary heat exchange case 23 while passing through the forward and return narrow tube groups 33a and 33b and absorbing the latent heat of the combustion exhaust gas. It will be. The heating side secondary heat exchanger 53 has the same structure as the hot water supply side secondary heat exchanger 33, and is provided between an inlet header 533 that communicates with the inlet 531 and an outlet header 534 that communicates with the outlet 532, and the return header 535. In addition, two groups of narrow tubes 53a and 53b on the forward side and the return side are stretched over and connected to each other.

  In addition, the code | symbols 231 and 431 in FIG. 3 are each a drain pipe which collects and collects exhaust gas drains, and code | symbols 232 and 432 are each a baffle plate. The baffle plate 232 is hung from below from the upper surface of the hot water supply side secondary heat exchange case portion 23 to block the combustion exhaust gas from the rear opening 26 from flowing linearly toward the exhaust cylinder 24, and the baffle plate 432 is on the heating side. The secondary heat exchange case portion 43 is erected upward from the lower surface of the secondary heat exchange case portion 43 so as to prevent the combustion exhaust gas from the rear surface opening 46 from flowing linearly toward the front surface opening 47.

  In the first embodiment described above, the flue gas from the heating side primary heat exchange case part 42 flows into the heating side secondary heat exchange case part 43 through the rear opening 46, and the narrow tube group 53 b of the secondary heat exchanger 53. , 53a and flowing toward the front opening 47, the latent heat of the combustion exhaust gas is absorbed by heat exchange with the low-temperature water in the thin tube groups 53a, 53b, and the low-temperature water is preheated. Here, for example, when the heating terminal 7 is supplied with high-temperature water at 80 ° C. and dissipates heat, and after heat dissipation, the low-temperature water at 60 ° C. is returned to the heating can 4, the heating-side primary heat exchanger If the combustion exhaust gas after heat exchange heating 42 is at 80 ° C., for example, the temperature difference between the low-temperature water to be preheated and the combustion exhaust gas is small, so that the combustion exhaust gas remains in the front opening with insufficient recovery of latent heat. 47 is fed into the hot water supply side secondary heat exchange case 23 through the communication path 6 and the front opening 27. On the other hand, in the hot water supply side secondary heat exchange case portion 23, the combustion exhaust gas from the hot water supply side primary heat exchange case portion 22 flows through the rear opening 26 and passes through the narrow tube groups 33 b and 33 a of the secondary heat exchanger 33. While flowing toward the cylinder 24, the latent heat of the combustion exhaust gas is absorbed by heat exchange with the incoming water in the thin tube groups 33a and 33b, and the incoming water is preheated and also preheated by the combustion exhaust gas from the heating side. Become. For example, even if the incoming tap water is 20 ° C. and this incoming water is preheated by the combustion exhaust gas from the hot water supply side primary heat exchanger 32 and preheated to 30 ° C., the heating side secondary heat exchange is performed through the communication passage 6. The latent heat of the combustion exhaust gas supplied from the case part 43 can be absorbed and preheated to a higher temperature. In short, by letting the combustion exhaust gas on the heating side pass through the heating side secondary heat exchanger 53 and not being discharged as it is, it is introduced into the hot water supply side secondary heat exchanger 33, so that the latent heat recovery on the heating side is insufficient. Unrecovered latent heat can be sufficiently recovered on the hot water supply side, whereby the latent heat recovery efficiency can be increased as much as possible to achieve higher efficiency.

  In addition, the combustion exhaust gas from the heating side is first introduced from the front side position (downstream side position) of the hot water supply side secondary heat exchange case 23, that is, the disposition position of the outgoing side narrow tube group 33 a from the inlet side header 333. Thus, the latent heat of the combustion exhaust gas from the heating side can be sufficiently recovered with higher recovery efficiency.

  Here, when the hot water supply operation is stopped (the hot water supply side combustion burner 31 is in the combustion stopped state) and only the heating operation is continued, the heating side secondary heat exchange case unit 43 to the hot water supply side secondary heat exchange case unit 23 are operated. Since the water in the hot water supply side secondary heat exchanger 33 is preheated in a staying state by the combustion exhaust gas supplied to the hot water supply side, the hot water supply side secondary heat exchanger 33 can also function as a kind of heat storage tank. It becomes like this. Conversely, when the heating operation is stopped (the heating-side combustion burner 51 is in the combustion-stopped state) and only the hot water supply operation is being performed, the heating side is used to prevent the backflow from the hot water supply side secondary heat exchange case section 23 to the heating side. Even if only the blower fan 54 is operated and blown, even if this blown air flows through the communication path 6 to the hot water supply side secondary heat exchange case 23, it is the position where the coldest incoming water flows, The resulting loss of thermal efficiency can be minimized.

Second Embodiment
FIG. 5: shows the principle schematic diagram of the hot water heater based on 2nd Embodiment of this invention. As in the first embodiment, this hot water heater is composed of a hot water supply circuit 3 having a hot water supply can body 2 and a heating circuit 5 having a heating can body 4 in two cans and two circuits, and a condensing type. However, the secondary heat exchanger 8 in which the hot water supply side secondary heat exchanger 81 and the heating side secondary heat exchanger 82 are integrated one above the other is used. Different from the first embodiment. Note that, except for those that are specifically described below, the same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and redundant detailed description is omitted.

  The secondary heat exchanger 8 is installed in a state where the hot water supply can body 2 and the heating can body 4 which are configured independently of each other are connected to each other. This connection structure is as follows. That is, as shown in FIG. 6, in the secondary heat exchanger 8, a hot water supply side secondary heat exchanger 81 is disposed in the upper case 83, and a heating side secondary heat exchanger 82 is disposed in the lower case 84. Has been. As shown in FIG. 7, the upper case 83 communicates with the hot water supply-side collective case portion 25 and the rear opening 29, and the lower case 84 communicates with the heating-side collective case portion 45 and the rear opening 49. Yes. The upper case 83 and the lower case 84 are partitioned by two partition plates 85 and 86 that are provided with a step in the vertical direction inside, and at the same time, are communicated with each other through a gap 87 as a communication path at the front position. Yes. In addition, an exhaust cylinder 88 projects forward from the front surface of the upper case 83 and opens. The exhaust pipe 88 may be disposed so as to protrude upward as indicated by reference numeral 88a in FIG. Further, reference numeral 831 in FIG. 7 is the drain pipe described in the first embodiment.

  As shown in FIG. 8, the hot water supply side secondary heat exchanger 81 in the upper case 83 is provided between an inlet header 812 that communicates with the inlet 811 and an outlet header 814 that communicates with the outlet 813, and the folded header 815. The two groups of narrow tubes 81a and 81b on the forward side and the return side are stretched and connected in communication. The incoming water that has entered from the inlet 811 is diverted to the forward-side narrow tube group 81a composed of a plurality of thin tubes at the inlet-side header 812, reaches the return header 815, and once merges at the return header 815, then is diverted again to the return-side narrow tube group 81b. It reaches the outlet header 814. And it merges by the exit side header 814, and is sent to the primary heat exchanger 32 (refer FIG. 5) through the exit 813. FIG. The heating-side secondary heat exchanger 82 in the lower case 84 has the same structure as described above, and includes an inlet-side header 822 that communicates with the inlet 821, an outlet-side header 824 that communicates with the outlet 823, and a folding header 825. Between these, two groups of narrow tube groups 82a and 82b on the forward side and the return side are stretched and connected in communication.

  Also in the case of the second embodiment, as in the first embodiment, the combustion exhaust gas with insufficient latent heat recovery on the heating side can be supplied to the hot water supply side so that the latent heat recovery can be sufficiently performed on the hot water supply side. Become. That is, the combustion exhaust gas from the heating side primary heat exchange case portion 42 flows into the lower case 84 through the rear side opening 49 and passes through the narrow tube groups 82b and 82a of the heating side secondary heat exchanger 82. While flowing toward the bottom, the latent heat of the combustion exhaust gas is absorbed by the low temperature water in the thin tube groups 82a and 82b by heat exchange, and the low temperature water is preheated. The combustion exhaust gas that has flowed up to the front side position of the lower case 84 flows into the upper case 83 from the gap 87. On the other hand, the combustion exhaust gas from the hot water supply side primary heat exchange case portion 22 flows into the upper case 83 through the rear opening 29, passes through the narrow tube groups 81b and 81a of the hot water supply side secondary heat exchanger 81, and the exhaust pipe. While flowing toward 88, the latent heat of the combustion exhaust gas is absorbed by heat exchange with the water in the narrow tube groups 81a and 81b to preheat the water, and the combustion exhaust gas from the heating side supplied through the gap 87 is supplied. Will also be preheated. As a result, the latent heat that has not been recovered on the heating side can be sufficiently recovered from the combustion exhaust gas on the heating side, and the incoming water on the hot water supply side can be preheated to a higher temperature.

  Moreover, also in the case of the second embodiment, the combustion exhaust gas from the heating side is supplied to the front side position (downstream side position) of the hot water supply side secondary heat exchanger section 81 at the position where the coldest water flows. Therefore, the latent heat of the combustion exhaust gas from the heating side can be sufficiently recovered with higher recovery efficiency. Also, when the hot water supply operation is stopped and only the heating operation is executed, or conversely, the same effects as those described in the first embodiment are provided as the effects when the hot water supply operation is executed only and the heating operation is stopped. Can also be obtained in the second embodiment.

  In addition, the exhaust gas drain generated in the upper case 83 is dropped into the lower case 84 by arranging the partition plates 85 and 86 of the second embodiment slightly downwardly inclined toward the gap 87 side. Water can be collected for treatment through a drain pipe 831.

  Various forms of the partition plates 85 and 86 and the gap 87 for allowing the combustion exhaust gas from the heating side to flow into the upper case 83 from the lower case 84 can be adopted. For example, as shown in FIG. 9, two partition plates 91 and 92 are separated in the front-rear direction (left-right position in the figure) in the front-rear direction (left-right direction in the figure), and a gap having a predetermined width (communication path) is formed therebetween. ) 93 may be formed. In this case as well, both partition plates 91 and 92 may be arranged in a downward gradient toward the gap 93 side. Alternatively, as shown in FIG. 10, one or more partition plates 94, 95 may be combined to open two or more gaps (communication paths) 96, 96,. In this case, the communication path may have any shape such as a gap or a hole, and the number thereof may be any one or more. Further, the baffle plate 97 may be suspended from the partition plate 94 toward the space of the lower case 84.

<Other embodiments>
The present invention is not limited to the first and second embodiments described above, but includes other various embodiments. That is, in the first and second embodiments, the hot water heater configured in two cans and two circuits is shown. However, the present invention is not limited to this. For example, a liquid / liquid heat exchanger is provided in the middle of the outgoing path 56 of the heating circuit 5. By connecting the liquid / liquid heat exchanger and the bathtub with a circulation path, a reheating circuit for reheating and heating the bathtub hot water is formed, thereby forming a 2-can 3 circuit. Also good.

  In addition, when the hot water supply circuit 2 is provided with a circulation pump and only the heating operation is executed when the hot water supply operation is stopped, the circulation pump is operated to remove the accumulated water in the secondary heat exchangers 33 and 81 in the hot water supply circuit 3. You may make it circulate. Thereby, the latent heat recovery when the combustion exhaust gas after passing through the heating side secondary heat exchangers 53 and 82 is supplied to the hot water supply side secondary heat exchangers 33 and 81 can be made more efficient. At this time, the circulating pump is not provided separately from the circulating pump 57 on the heating circuit 5 side, but only rotating blades or water turbines are also provided on the hot water supply circuit 3 side. You may make it receive the rotational driving force from a motor.

  Furthermore, in the second embodiment, the hot water supply side secondary heat exchanger 81 is disposed in the upper case 83 and the heating side secondary heat exchanger 82 is disposed in the lower case 84. May be. This is because if the exhaust pipe is installed in the case on the side where the hot water supply side secondary heat exchanger is arranged even if it is turned upside down, the combustion exhaust gas flows from the heating side to the hot water supply side.

It is a schematic diagram which shows 1st Embodiment of this invention in principle. It is a perspective view which shows the more specific shape and structure of a can body. 3A is a cross-sectional explanatory view taken along line AA in FIG. 2, and FIG. 3B is a cross-sectional explanatory view taken along line BB in FIG. It is a perspective view for demonstrating the structure of a secondary heat exchanger. It is a schematic diagram which shows 2nd Embodiment theoretically. It is a perspective view which shows the shape and structure more specifically of a can body. 7A is a cross-sectional explanatory view taken along line CC in FIG. 6, and FIG. 7B is a cross-sectional explanatory view taken along line DD in FIG. It is a disassembled perspective view for demonstrating the structure of a secondary heat exchanger. FIG. 9A shows another mode different from FIG. 7, FIG. 9A is a corresponding diagram of FIG. 7A, and FIG. 9B is a corresponding diagram of FIG. 7B. FIG. 10 shows another mode different from FIG. 7 or FIG. 9, FIG. 10 (a) is a corresponding diagram of FIG. 7 (a), and FIG. 10 (b) is a corresponding diagram of FIG. 7 (b). It is a figure corresponding to FIG. 1 which shows the example of the conventional hot-water supply heater.

Explanation of symbols

2 Hot water supply can body 3 Hot water supply circuit 4 Heating can body 5 Heating circuit 6 Communication path 33, 81 Hot water supply side secondary heat exchanger 53, 82 Heating side secondary heat exchanger 87, 93, 96 Clearance (communication path)

Claims (4)

The hot water supply circuit and the hot water circulation type heating circuit are each a hot water supply heater equipped with a secondary heat exchanger for collecting latent heat,
Both the secondary heat exchangers are communicated so that the flue gas generated by the combustion operation of the heating circuit passes through the secondary heat exchanger on the heating circuit side and is supplied to the secondary heat exchanger on the hot water supply circuit side. A hot water heater provided with a communication passage. A hot water heater according to claim 1,
The hot water supply circuit and the heating circuit are configured in two cans and two circuits so that the combustion operation can be performed independently of each other.
The secondary heat exchanger on the side of the hot water supply circuit and the secondary heat exchanger on the side of the heating circuit are integrated in a state where they are arranged at upper and lower positions and separated from each other, and a communication passage is provided through the partition. There is a hot water heater. A hot water heater according to claim 1,
The hot water supply circuit and the heating circuit are configured in two cans and two circuits so that the combustion operation can be performed independently of each other.
The secondary heat exchanger on the hot water supply circuit side and the secondary heat exchanger on the heating circuit side are provided independently of each other, while the installation spaces of both secondary heat exchangers are connected to each other via a communication path. , Hot water heater. A hot water heater according to any one of claims 1 to 3,
The communication path is configured so that the combustion circuit operates toward the portion corresponding to the downstream side when the combustion exhaust gas generated by the combustion operation of the hot water supply circuit is supplied toward the secondary heat exchanger on the hot water supply circuit side. A hot water heater that is arranged so that the combustion exhaust gas generated by the gas is supplied.

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