JP5089938B2 - Heat exchange device and combustion device equipped with the same - Google Patents

Description

  The present invention is applied to, for example, a water heater, a boiler, an absorption chiller / heater, a gas engine device, a gas turbine device, a fuel cell, and the like, and includes a heat exchange device that performs heat exchange by receiving heat of combustion gas, and the same. The present invention relates to a combustion apparatus.

  FIG. 12 schematically shows an example of a water heater that is a combustion apparatus. Conventionally, various combustion apparatuses as shown in this figure have been proposed. In the figure, a burner 1 is disposed in a combustion chamber 20 provided in an instrument case 40, and a gas pipe 42 for supplying fuel to the burner 1 is connected to the burner 1. An open / close valve (not shown) for controlling supply / stop of fuel to the burner 1 and a proportional valve (not shown) capable of controlling the amount of fuel supplied to the burner 1 with the valve opening degree are interposed. It is installed.

  A combustion fan 5 that supplies and exhausts combustion of the burner 1 is provided below the burner 1. This water heater supplies air that is sucked from the outside to the burner 1 by the rotation of the combustion fan 5, performs burner combustion with this air and gas supplied through the gas pipe 42, and is generated by the burner combustion. The combustion gas is sent from the combustion chamber 20 to the exhaust port 8 side and exhausted by the rotation of the combustion fan 5.

  Above the burner 1, a main heat exchanger (primary heat exchanger) 4 that recovers sensible heat in the combustion gas of the burner 1, and a flow of the combustion gas downstream from the main heat exchanger 4. Latent heat recovery heat exchangers (secondary heat exchangers) 6 that are provided on the side and recover the sensible heat and latent heat of the combustion gas are arranged at intervals. Each of the heat exchangers 4 and 6 has a heat receiving pipe 34, 3 made of metal or the like through which water as a heat receiving fluid that receives the heat of the combustion gas of the burner 1 and the outside of the heat receiving pipes 34, 3 receive the heat. The heat pipes 34 and 3 and a plurality of fins 35 and 37 provided substantially vertically are provided, and the fins 35 and 37 are provided at intervals.

  A water supply pipe 46 serving as a water supply passage led from a water supply source is connected to the inlet side of the latent heat recovery heat exchanger 6, and the outlet side of the latent heat recovery heat exchanger 6 and the main heat exchanger are connected. The inlet side of 4 is connected via a connecting pipe 48. A hot water supply pipe 47 is connected to the outlet side of the main heat exchanger 4. In FIG. 12, the water supply pipe 46, the hot water supply pipe 47, and the connection pipe 48 are schematically shown by linear arrows, respectively, but the water supply pipe 46, the hot water supply pipe 47, and the connection pipe 48 circulate water. For example, a pipe having a circular cross section.

  Normally, the water supply pipe 46 has a water thermistor (not shown) that detects the temperature of water supplied from the water supply pipe 46 and flows into the latent heat recovery heat exchanger 6, and the water that flows into the latent heat recovery heat exchanger 6. The hot water supply pipe 47 is provided with a hot water thermistor (not shown) capable of detecting the temperature of the hot water flowing out.

  Under the latent heat recovery heat exchanger 6, an appropriate drain discharge means for discharging the drain generated in the latent heat recovery heat exchanger 6 to the outside is provided. In the water heater shown in this figure, a drain tray 43 and a drain pipe 44 connected to the tray 43 are provided as drain discharge means. The distal end side of the drain pipe 44 is led out of the instrument case 40 and is configured to discharge the condensed water droplets accumulated in the receiving tray 43 to the outside.

  Combustion control of the burner 1 and rotation control of the combustion fan 5 are performed according to a sequence program given in advance by a combustion control device (not shown) based on detection signals of the respective sensors. The burner 1 is combusted by the gas supplied from the gas pipe 42 and the air sent by the combustion fan 5. As the burner 1 burns, the hot water heater passes through the water supply pipe 46 through the latent heat recovery heat exchanger 6 and the main heat exchanger 4 in order to make hot water. It has a hot water supply function that leads the hot water first.

  In the water heater provided with the latent heat recovery heat exchanger 6, the high-temperature combustion gas from the burner 1 is disposed from the upper side of the burner 1 to the main heat exchanger 4, for example, as indicated by the broken arrow in FIG. 12. It passes through the installation area, passes through the lower side of the receiving tray 43, and enters the arrangement area side of the latent heat recovery heat exchanger 6 from the horizontal direction side. And the combustion gas which passed the arrangement | positioning area | region of the heat exchanger 6 for latent heat collection | recovery is exhausted from the exhaust port 8 side.

  Then, while the combustion gas passes through the main heat exchanger 4, heat exchange is performed between the combustion gas and water supplied to the main heat exchanger 4, and sensible heat of the combustion gas is recovered. . Further, while the combustion gas that has passed through the main heat exchanger 4 passes through the latent heat recovery heat exchanger 6, heat exchange is performed between the combustion gas and water supplied to the latent heat recovery heat exchanger 6. Thus, the sensible heat and latent heat of the combustion gas are recovered.

  The latent heat recovery of the combustion gas by the latent heat recovery heat exchanger 6 is performed by bringing the combustion gas containing water vapor into contact with the low temperature heat transfer surface below the saturation temperature to condense the water vapor in the combustion gas. That is, it recovers the latent heat of condensation that occurs when water vapor condenses, and usually recovers the enthalpy of the water vapor of the combustion gas that is discharged out of the combustion system such as a water heater as the combustion gas. is there.

  Thus, in the water heater provided with the latent heat recovery heat exchanger 6, when the combustion gas generated by the combustion of the burner 1 passes through the latent heat recovery heat exchanger 6, the water pipe in the latent heat recovery heat exchanger 6 is connected. The passing water takes away the latent heat held by the water vapor in the combustion gas (collects the latent heat) to increase the temperature, and is further heated by the combustion thermal power of the burner 1 when passing through the main heat exchanger 4. Since hot water having a set temperature is produced, the burner 1 can perform efficient heating.

  That is, by providing the heat exchanger 6 for recovering latent heat, for example, in a water heater, the thermal efficiency reaches about 90% or more on a high heating value (total heating value) basis, and the heat exchanger 6 for recovering latent heat is provided. High thermal efficiency is achieved compared to a normal water heater without.

  In addition, as for the main heat exchanger 4 and the latent heat recovery heat exchanger 6 applied to the combustion apparatus as described above, those having various configurations such as those not having the fins 35 and 37 have been proposed. FIG. 13 shows a schematic perspective view of a proposed example of the latent heat recovery heat exchanger 6 having no fins (see, for example, Patent Documents 1 and 2).

  The latent heat recovery heat exchanger 6 has a plurality of heat receiving pipes 3 arranged in parallel in the combustion gas circulation passage 2 in a direction crossing the flow of combustion gas (in the direction of arrow g in the figure). Is formed. In this figure, although the number of the heat receiving pipes 3 is shown in a simplified manner, in actuality, the heat receiving pipes 3 are disposed in the combustion gas circulation passage 2 in the vertical direction (Z direction) and the horizontal direction. A plurality are arranged in the direction of arrow g.

  Headers 16 and 17 are provided on the end side of the heat receiving pipe 3, and a plurality of the heat receiving pipes 3 on one end side are connected together by the headers 16 (16 a to 16 d), and the receiving on the other end side is connected. A plurality of the heat pipes 3 communicate with each other through the headers 17 (17a to 17c). The headers 16a to 16d and the headers 17a to 17c are provided so as to be shifted from each other, and the water introduced into the header 16a from the water supply passage is shown in the simplified schematic diagram of FIG. It proceeds in a meandering manner through the path 3 and the headers 16b, 16c, 17a to 17c, and is derived from the header 16d.

  In the side view of FIG. 14B, the configuration of the latent heat recovery heat exchanger 6 shown in FIG. 13 is simplified in the number and arrangement of the heat receiving pipes 3, and the water flow direction and the combustion gas are shown. The flow direction g of (combustion exhaust gas) is typically shown.

JP 2004-239467 A Japanese Patent Laying-Open No. 2005-274028

  By the way, although the combustion apparatus provided with the latent heat recovery heat exchanger has high thermal efficiency as described above, in recent years, further improvement in the thermal efficiency of the combustion apparatus has been demanded, and accordingly, the heat exchanger (heat There has been a demand to further improve the recovery of heat in the combustion gas by the exchange device.

  For this reason, for example, the number of heat receiving pipes may be increased or the length thereof may be increased. However, when the number of heat receiving pipes is increased, the size of the heat exchanger and the pressure loss of water flow are reduced accordingly. This leads to an increase (decreased hot water performance), resulting in a problem that the combustion apparatus equipped with the heat exchange device is increased in size.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a highly efficient and compact heat exchange device and its heat exchange device that can suppress passage pressure loss of a heat receiving fluid such as water. An object of the present invention is to provide a combustion apparatus with high thermal efficiency.

In order to achieve the above object, the present invention has the following configuration as means for solving the problems. That is, the heat exchange device according to the first aspect of the present invention is a heat exchange device that is provided in a gas flow path through which combustion gas flows and recovers the heat of the combustion gas, and is vertically moved in the space in which the combustion gas flows. A plurality of heat receiving duct groups arranged in a manner of being stacked in a plurality of stages are provided, and the heat receiving duct groups in each stage are spaced apart from each other by straight heat receiving ducts that pass the heat receiving fluid that receives the heat of the combustion gas. A plurality of the heat receiving pipe groups of each stage in the direction crossing the passage through which the combustion gas flows. The pipe communication means is arranged in an array, and the pipe communication means on one end side of the arrangement of the pipe communication means on one end side and the other end side of the heat receiving pipe line is the pipe communication means on the heat receiving fluid introduction side. Formed by the plurality of heat receiving pipes from the pipe connecting means on the introduction side of the heat receiving fluid. The pipe connection means arranged on the one end side and the other end side of the heat receiving pipe line are alternately connected to each other, and proceeds to the pipe connection means of the final connection destination located on the other end side of the arrangement of the pipe connection means. A continuous communication passage for the heat pipe is formed, and the pipe connection means at the final connection destination is formed as a pipe connection means on the outlet side of the heat receiving fluid, and is supplied from the outside without being heated by the heat of combustion. The heat receiving fluid is branched into a plurality of parts and introduced into the pipe communication means on the heat receiving fluid introduction side of each of the heat receiving pipe groups at each stage, and the heat receiving fluid that has passed through the heat receiving pipe group at each stage is supplied to each stage. The heat receiving pipe line group of the heat receiving fluid pipes is joined together at a fluid confluence section connected to the outlet side pipe communicating means of the heat receiving fluid and is led out collectively, and a partition is provided between the heat receiving pipe line groups of the respective stages. The gas distribution path of the combustion gas that is provided with the members and passes through the heat receiving pipe group of each stage is divided, and the gas distribution path Is provided with a turn-back portion for returning the combustion gas from the gas flow path of the lower heat receiving pipe group to the gas flow path of the upper heat receiving pipe group, so that the combustion gas is in the lowermost stage. It is characterized by being discharged from the gas flow path of the uppermost heat receiving pipe line group through the gas flow path of the upper heat receiving pipe line group sequentially from the gas flow path of the heat receiving pipe line group.

In addition to the configuration of the first invention, the heat exchanging device of the second invention is such that the pipe connecting means on the heat receiving fluid introduction side of the heat receiving pipe group of each stage is a common pipe connecting means. The pipe receiving means for the heat receiving fluid in each stage of the heat receiving pipe group is also constituted by one common pipe connecting means, and the heat receiving fluid supplied from outside without being heated by the heat of combustion is The heat receiving fluid introduced into the common one pipe connecting means and introduced by the pipe connecting means is distributed and supplied to the heat receiving pipes of the heat receiving pipe groups of the respective stages, and passes through the heat receiving pipes of the respective stages. The heat receiving fluid is merged by the common pipe communication means on the outlet side of the heat receiving fluid and is derived from the common pipe communication means.

Furthermore, in the heat exchange device of the third invention, in addition to the configuration of the second invention, the heat receiving pipe line group has a two-stage stacked structure, and the flow path of the heat receiving pipe line of the heat receiving pipe line group of each stage Is a flow passage of a plurality of heat receiving pipes formed by communicating pipe connecting means arranged at one end and the other end of the heat receiving pipe, and the pipe connecting means on the introduction side of the heat receiving fluid is a heat passage. It is arranged on the combustion gas inlet / outlet side with respect to the exchange device, and the outlet communication means on the outlet side of the heat receiving fluid is on the folded portion side where the combustion gas folds back to the upper heat receiving pipe group through the lower heat receiving pipe group. It is arranged. Furthermore, in the heat exchange device of the fourth aspect of the invention, in addition to the configuration of the second or third aspect of the invention, the plurality of stages of gas flow paths have smaller path diameters for each stage toward the exhaust side of the combustion gas. It is formed. Furthermore, a heat exchange device according to a fifth aspect of the present invention, in addition to the configuration of any one of the first to fourth aspects of the present invention, is characterized in that the heat receiving pipe line has a bellows tube having irregularities formed in a bellows shape along the longitudinal direction. It is characterized by that.

Furthermore, the heat exchange device of the sixth invention is a latent heat recovery heat exchange device for recovering the latent heat of the combustion gas in addition to the configuration of any one of the first to fifth inventions. It is characterized by.

Furthermore, a combustion apparatus according to a seventh aspect is characterized by including the heat exchange apparatus according to any one of the first to sixth aspects.

Furthermore, a combustion apparatus according to an eighth aspect of the invention includes a hot water supply function in addition to the configuration of the seventh aspect of the invention, wherein the heat receiving fluid is water, and the water is passed through a heat exchange device to create hot water and supply hot water to a hot water supply destination. It is characterized by.

The heat exchanging device of the present invention forms a plurality of heat receiving pipe groups that communicate with a plurality of heat receiving pipes via pipe connecting means provided at one end and the other end of the heat receiving pipe, The heat receiving fluid is introduced into pipe communication means on the introduction side of the heat receiving fluid on one end side of the heat receiving pipe group corresponding to each of the plurality of heat receiving pipe groups, and the heat receiving fluid passing through each heat receiving pipe group is added to the other of the heat receiving pipe groups. It has the structure which joins and derives | leads-out in the fluid confluence | merging part connected to the pipe line communication means of the outgoing side of the heat receiving fluid of an end side. Therefore, each heat receiving pipe is compared with the conventional example in which the heat receiving fluid supplied from the heat receiving fluid supply side is introduced into the heat receiving pipe without branching under the condition that the diameter and number of the heat receiving pipes are constant. Since the amount of heat receiving fluid flowing through the path can be reduced, the passage pressure loss of the heat receiving fluid can be reduced.

  Therefore, in the heat exchanging device of the present invention, when trying to make the passage pressure loss of the heat receiving fluid equal to the conventional example in which the heat receiving fluid is introduced into the heat receiving pipe without branching, the present invention is compared with the conventional example. The diameter of the heat receiving pipe can be reduced, or the number of heat receiving pipes can be reduced, and the diameter of the gas flow path can be reduced accordingly, so that the combustion gas flow rate can be increased to improve the thermal efficiency. In addition, the apparatus can be made compact. That is, the heat exchange device of the present invention and the combustion device including the heat exchange device can be realized by combining the suppression of the passage pressure loss of the heat receiving fluid such as water, the improvement of thermal efficiency, and the compactness of the device.

  Even if the heat receiving fluid is not branched as in the present invention, the combustion gas flow path is narrowed to increase the flow speed of the combustion gas, or the heat receiving pipe is narrowed to the internal volume of the heat receiving pipe. Increasing the surface area ratio is considered to improve the thermal efficiency without increasing the size of the heat exchange device, but with the heat receiving pipe diameter narrowed, the heat receiving pipe is passed through a thick heat receiving pipe. When a heat receiving fluid equivalent to the flow rate is flowed, the passage pressure loss increases and the flow of the heat receiving fluid becomes faster, resulting in erosion and corrosion.

  On the other hand, if the heat receiving fluid is branched and introduced as in the present invention, the amount of the heat receiving fluid introduced into the heat receiving pipe is reduced. Since the speed of the flowing heat receiving fluid can be suppressed (because it can be kept at a speed at which erosion corrosion does not occur), the heat receiving pipe can be narrowed to improve the heat efficiency of the heat exchange device. The exchange device can also be made compact. In addition, if the flow path of the combustion gas is made narrower in correspondence with the narrowing of the heat receiving pipe, the flow rate of the combustion gas can be improved, so that the heat recovery by the heat receiving fluid can be performed more efficiently, and the thermal efficiency Can be improved.

Further, the present invention is provided with a plurality of heat receiving pipe line groups arranged in a manner of being stacked in a plurality of stages in the vertical direction in the space where the combustion gas flows, and comes out of the gas flow path of the lower heat receiving pipe line group A folding section is provided for the combustion gas to be folded and introduced into the gas flow path of the upper heat receiving pipe group, and the upper heat receiving pipe is sequentially arranged from the gas flow path of the lower heat receiving pipe group. the construction further through the gas flow path of the road group is discharged from the gas flow path of the uppermost heat receiving pipe group, by forming a gas flow path in a plurality of stages, the longitudinal length of the heat exchange device The length can be shortened and the combustion apparatus can be made compact.

  Further, normally, the flow rate of the combustion gas decreases as the temperature of the combustion gas decreases as it goes to the exhaust side. In the present invention, the gas flow in a plurality of stages of the heat exchange device progresses toward the exhaust side of the combustion gas. By forming a path with a small path diameter for each stage, the flow velocity of the combustion gas can be increased even on the exhaust side of the combustion gas, and the thermal efficiency can be further improved.

  Furthermore, in the present invention, according to the configuration in which the heat receiving pipe of the heat exchange device is a bellows pipe having irregularities formed in a bellows shape along the longitudinal direction, the heat receiving pipe is formed by a straight pipe. Since the surface area of the heat receiving pipe can be increased as compared with the case where the heat is received, the heat of the combustion gas can be recovered more efficiently even if the fins are not provided.

  Furthermore, if the heat exchange device of the present invention is a latent heat recovery heat exchange device that recovers the latent heat of the combustion gas, the latent heat of the combustion gas can be efficiently recovered with a compact latent heat recovery heat exchanger. It is possible to improve the thermal efficiency of the combustion device or the like.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the present embodiment, the same reference numerals are assigned to the same names as those in the conventional example, and the duplicate description is omitted or simplified.

In the description of the present embodiment example, for the convenience of description, first, a reference example of the embodiment example will be described. FIG. 1 (a), (b), the configuration of one reference example with respect to implementation embodiments of the heat exchanger according to the present invention, schematically with the flow and the flow of the combustion gas of water flowing in the heat exchange device Has been shown. 1A is a plan view and FIG. 1B is a side view. The heat exchange device of this reference example is, for example, a latent heat recovery heat exchange in a water heater provided with a latent heat recovery heat exchanger 6 and a main heat exchanger 4 as in the conventional combustion device shown in FIG. Applied as a device 6.

  The latent heat recovery heat exchanger 6 has a plurality of heat receiving pipes 3 arranged in parallel in a direction crossing the flow of the combustion gas (arrow g) with a space therebetween. Note that FIG. 1A shows only the heat receiving pipe 3 provided at the top of the plurality of heat receiving pipes 3 arranged in parallel for easy understanding.

  On the side surface side of the latent heat recovery heat exchanger 6, a header 16 serving as a pipe communication means for communicating a plurality of heat receiving pipes 3 on one end side of the heat receiving pipe 3 together and a heat receiving pipe 3 on the other end side. A header 17 is provided as a pipe communication means for communicating a plurality of them together. These headers 16 and 17 are provided so as to be displaced from each other, and a plurality of heat receiving pipe line groups 7 (7a and 7b) in which a plurality of heat receiving pipe lines 3 are connected via the headers 16 and 17 (here, 2 One) is formed.

In addition, the water supply pipe 46 is branched into a plurality (two in this case) at the branch portion 19, and the branch tip side (the tip side of the branch pipe 20) of the heat receiving pipe line group 7 (7 a, 7 b) respectively corresponds. The headers 16c, 16f on the other end side of the heat receiving pipe line group 7 (7a, 7b) are connected to the fluid junction 21 via the junction pipe 22, respectively. . With this configuration, the reference example branches the water introduced into the water supply pipe 46 and supplies the water to the headers 16a and 16d on one end side of the corresponding heat receiving pipe group 7a and 7b, respectively. The water that has passed through 7b is joined at the fluid junction 21 via the headers 16c and 16f and the junction pipe 22 and led to the connection pipe 48.

  Describing in detail the flow of water, as shown in FIG. 1A, on the side of the heat receiving pipe group 7a, the branch pipe 20 → header 16a → heat receiving pipe 3 → header 17a → heat receiving pipe 3 → header 16b → receiving Heat pipe 3 → header 17b → heat receiving pipe 3 → header 16c → junction pipe 22 → connection pipe 48. On the heat receiving pipe group 7b side, the branch pipe 20 → header 16d → heat receiving pipe 3 → header 17c → heat receiving pipe 3 → header 16e → heat receiving pipe 3 → header 17d → heat receiving pipe 3 → header 16f → The joining pipe 22 is changed to the connecting pipe 48.

  FIG. 1B schematically shows the flow of water and combustion gas in the longitudinal direction of the gas flow path 2, and the headers 16b and 16e are indicated by broken lines. As shown in this figure, the water that has passed through the branch pipe 20 is introduced into the heat receiving pipe groups 7a and 7b from the center side of the gas flow path 2 and is led out from both ends of the gas flow path 2 to join. And introduced into the connecting pipe 48. The flow of water in the gas distribution path 2 has a flow from the exhaust outlet side to the inlet side (flow on the heat receiving pipe group 7a side) and the opposite flow (flow on the heat receiving pipe group 7b side). Become.

This reference example is configured as described above, and the water introduced into the water supply pipe 46 is branched and supplied to the corresponding heat receiving pipe line groups 7 (7a, 7b). Since the amount of water flowing through each heat receiving pipe 3 can be reduced as compared with the case where the heat receiving pipe 3 is introduced without branching, the water pressure loss (water pressure loss) can be reduced. In other words, in the reference example, when the heat exchange device is formed so that the pressure loss and the thermal efficiency are constant, the device can be made more compact than the conventional example.

The inventor makes the diameter and arrangement pitch of the heat receiving pipe lines 3 equal to each other for the heat exchange apparatus of the reference example and the conventional heat exchange apparatus as shown in FIGS. The relationship between the heat transfer area Aw and the water pressure loss ΔPw was determined by analysis with the recovered heat amounts being equal to each other and the flow velocity of the combustion gas being constant (equal to each other). The result is shown in FIG.

● is the value of the reference example, and ▲ is the value of the conventional example. In FIG. 2, the horizontal axis indicates the value obtained by dividing the heat transfer area of the conventional heat exchange device and the heat exchange device of the reference example by the heat transfer area of the heat exchange device of the reference example, and the vertical axis indicates The values obtained by dividing the water pressure loss of the conventional heat exchange device and the heat exchange device of the reference example by the water pressure loss of the heat exchange device of the reference example are shown. As shown in this figure, it was found that the reference example can obtain the same amount of recovered heat with a heat transfer area equivalent to that of the conventional example, and can suppress the water pressure loss to about 1/9.

Next, a heat exchange device according to an embodiment of the heat exchange device according to the present invention will be described. The configuration of the heat exchange device of the present embodiment is shown by a schematic side view in FIG. 3A. The characteristic of the present embodiment that is different from the above reference example is that the gas flow path 2 has One folding portion 15 is provided in a direction overlapping in the vertical direction, and the gas flow path 2 is formed in a plurality of levels (here, two levels) in the vertical direction. From a different viewpoint, the present embodiment can also be regarded as a mode in which the gas flow path 2 in the above reference example is folded by the folding unit 15.

In this embodiment, the branch pipe 20 and the junction pipe 22 provided in the reference example are not provided, and the headers 16a and 16d are straddled over the upper and lower gas flow paths 2 as shown in FIG. The water supply pipe 46 is connected to the central part of the header 16a, and the connection pipe 48 is connected to the central part of the header 16d. And the connection part to the header 16a of the water supply pipe 46 comprises the branch part 19 of water, and the connection part to the header 16d of the connection pipe 48 comprises the water merge part 21. The flow of water in the headers 16a and 16d is as shown in FIG. 3B, and FIG. 3A schematically shows the outline of the flow of water.

One header 16 for introducing water is provided in each of the upper and lower gas circulation paths 2, and one header 16 for water discharge is provided in each of the upper and lower gas circulation paths 2, and each of the upper and lower headers 16 is provided. The heat exchanger can also be formed by connecting the branch pipe 20 or the junction pipe 22, but the upper and lower headers 16a and 16d for introducing and discharging water are arranged one by one as in this embodiment. If it is set as the aspect provided in the aspect over the gas distribution path 2, an apparatus structure can be simplified.

In this embodiment, the partition wall 23 that partitions the upper and lower gas flow paths 2 is formed of a metal flat plate, but the partition wall 23 is formed of various metal plates such as corrugated plates and punching plates. It can be formed by a heat insulating material such as ceramic wool, or can be formed by a porous body such as sintered metal.

This embodiment can also achieve the same effects as the above reference example.

The present inventor compared the heat exchange device of this embodiment example with the heat exchange device shown in FIG. It examined as follows. Note that the heat exchange device shown in FIG. 15 (a) has the entire volume of the gas flow path 2 of the heat exchange device formed equal to the total volume of the gas flow path 2 in the heat exchange device of the present embodiment. It is formed so that water flows from one end side (exhaust outlet side) of the gas flow path 2 to the other end side (exhaust inlet side).

In FIG. 4, the water pressure loss is made equal to each other for the heat exchange device of the present embodiment and the heat exchange device shown in FIG. 15A, and the diameter, number, and arrangement pitch of the heat receiving pipes 3 are made to be equal values. The result of having calculated | required the relationship between water pressure loss (DELTA) Pw and the recovery | restoration heat quantity Q by making the heat-transfer area constant is shown.

  ● is the value for the heat exchange device of this embodiment, and ■ is the value for the heat exchange device of the conventional example shown in FIG. In FIG. 4, the horizontal axis represents the water pressure loss of the heat exchange device of the conventional example (see FIG. 15A) and the water pressure loss of the heat exchange device of the present embodiment, respectively. The vertical axis represents the value obtained by dividing the amount of recovered heat of the heat exchanger of the conventional example and the heat exchanger of the present embodiment by the amount of recovered heat of the heat exchanger of the conventional example. Further, Δ in FIG. 4 is a value obtained by dividing and analyzing the conventional heat exchange apparatus shown in FIG. 14B by dividing by the value of the conventional heat exchange apparatus in FIG. It is shown.

As clear from FIG. 4 of ● and ■ the Comparing, in the conventional example and the present embodiment, when the water pressure loss equal, the present embodiment is a conventional example of shown in Fig. 15 (a) It turned out that it becomes a highly efficient apparatus which can obtain about 1.16 times the amount of recovered heat. This is because when the present embodiment is compared with the heat exchange device of FIG. 15A, the width of the gas flow path 2 is narrow (about half), so the flow rate of the combustion gas is fast, This is because the heat transfer efficiency can be improved.

On the other hand, in the configuration of the conventional example, in order to obtain the recovered heat amount equivalent to that of the present embodiment example, the configuration shown in FIG. 14B is applied. In this case, as shown by Δ in FIG. It can be seen that the water pressure loss is about 10 times that of the present embodiment.

Next, the relationship between the heat transfer area Aw and the recovered heat quantity Q was determined by analysis for the heat exchange device of the present embodiment and the heat exchange device shown in FIG. . The result is shown in FIG. In this study, the heat exchange device of the present embodiment and the heat exchange device of FIG. 15A are configured such that the entire volume of the gas flow path 2 is equal to each other.

  ● is the value of this embodiment example, and ■ is the value of the conventional example shown in FIG. In FIG. 5, the horizontal axis divides the heat transfer area of the heat exchange device of the conventional example (see FIG. 15A) and the heat exchange device of this embodiment by the heat transfer area of the heat exchange device of the conventional example. The vertical axis represents the value obtained by dividing the amount of recovered heat of the heat exchanger of the conventional example and the heat exchanger of the present embodiment by the amount of recovered heat of the heat exchanger of the conventional example.

As is clear from comparison between ● and ■ in FIG. 5, when the heat transfer area is the same in the conventional example and the present embodiment, the present embodiment is about 1.16 times the conventional example. It turned out that it becomes a highly efficient apparatus which can obtain the amount of recovered heat. In addition, in order to obtain the recovered heat amount equivalent to that of the heat exchange device of the present embodiment with the configuration of the conventional example, the heat transfer area is 1.25 times that of the present embodiment as shown by □ in FIG. Therefore, it is necessary to take a configuration as shown in FIG. In this case, the water pressure loss increases 1.25 times.

As described above, the heat exchange device of the present embodiment, which can realize the suppression and high efficiency and compactness of the passage pressure loss of the water, which, in this embodiment the heat exchanger is water This can be realized by having the branch introduction and the two-stage configuration of the gas flow path 2. That is, for example, as in the modification of the conventional example shown in FIG. 16, only the water path is folded, and the flow of water has a flow from the exhaust outlet side toward the exhaust inlet side and vice versa. In the configuration of FIG. 16 in which the water is supplied to each heat receiving pipe 3 without branching, and the width of the gas exchange path 2 is the same as that of the heat exchange device in FIGS. 15 (a) and 15 (b), The effects of the present embodiment, such as suppression of loss and increase in combustion gas flow velocity, cannot be achieved.

The present invention is not limited to the above you facilities embodiment, it may take a variety of aspects. For example, in the above you facilities embodiment, the gas distribution channel 2 in the central heat receiving pipe from side passageway groups 7a of the heat exchanger, by introducing water each to 7b, to derive the respective water from both sides of the gas distribution channel 2 However, as shown in FIG. 6 ( b), water is introduced into the heat receiving pipe groups 7 a and 7 b from both ends of the gas circulation path 2, and water is led out from the center of the gas circulation path 2. It may be. In FIG. 6A, for reference, water is introduced into the heat receiving pipe groups 7a and 7b from both ends of the gas circulation path 2 in the above reference example, and water is introduced from the center of the gas circulation path 2 respectively. An example of derivation is shown.

Further, in the above you facilities embodiment, the heat-receiving channel 3 two heat receiving pipe group 7a communicated by the header 16 and 17, were formed 7b, FIG. 7 (b), a schematic diagram of (d) As shown respectively, the heat receiving pipe line 3 communicates with the headers 16 and 17 to form three heat receiving pipe group groups 7a, 7b and 7c, and the water introduced from the water supply pipe 46 is divided into three parts. It may be introduced into the heat receiving pipe group 7a, 7b, 7c, and the water passing through these heat receiving pipe groups 7a, 7b, 7c may be merged and derived at the junction. Alternatively, four or more heat receiving pipe line groups 7 may be formed, water may be branched and introduced into each heat receiving pipe line group 7, and the water passing through each heat receiving pipe line group 7 may be merged and led out. 6 (a) and 6 (c), as a reference, in the above reference example, the heat receiving pipe line 3 is communicated by the headers 16 and 17 to form three heat receiving pipe group groups 7a, 7b, and 7c. The water introduced from the water supply pipe 46 is branched into three and introduced into each heat receiving pipe group 7a, 7b, 7c, and the water passing through these heat receiving pipe groups 7a, 7b, 7c is joined at the junction. An example of derivation is shown below.

Further, when three or more heat receiving pipe line groups 7 are formed and the gas flow paths 2 are formed in a plurality of stages, as shown in FIG. 8, a plurality of (here, three stages) gas flow paths 2 are formed. (2a, 2b, 2c) may be formed so that the path diameter becomes smaller for each stage (for each of the gas flow paths 2a, 2b, 2c) toward the exhaust side of the combustion gas. If the gas flow path 2 is formed in this way, it is possible to suppress a decrease in exhaust gas flow velocity resulting from a decrease in exhaust volume caused by a decrease in exhaust gas temperature on the exhaust outlet side, and to increase the flow velocity of combustion gas on the exhaust gas side, can it to improve more the thermal efficiency.

Furthermore, in the above embodiment, instead of the gas flow path 2 is formed in a plurality of stages partitioned by a partition wall, providing a partition wall that partitions the remarkable gas distribution channel 2, as shown in FIG. 9, the heat receiving pipe 3 may be formed without a gap to form a partition. If it does in this way, since the heat of combustion gas can be collect | recovered also by the heat receiving pipe line group 3 arrange | positioned in the partition shape, the thermal efficiency of a heat exchanger can be improved further.

Furthermore, in the above you facilities embodiment, although communication in a plurality of the heat-receiving channel 3 by the one end and the other end and to the header 16, 17 each of the heat receiving pipe 3 provided, as shown in FIG. 10, The heat receiving pipe lines 3 may be individually communicated by providing a U-shaped pipe 25 or the like (including a mode in which the heat receiving pipe lines 3 are juxtaposed by folding back the communicating pipe lines at their end portions).

Furthermore, in the above you facilities embodiment, the heat receiving pipe 3 is formed by the bare pipe which is not provided with fins, it may be provided with fins on the outer peripheral side of the heat receiving pipe 3. Further, the bellows heat-receiving channel 3, as above you facilities embodiment, may be formed by a straight line, as shown in FIG. 11, the unevenness like bellows in the longitudinal direction is formed It may be made of a tube.

  Further, in the above description, the example in which the heat exchange device is applied to the latent heat recovery heat exchanger 6 has been described. However, the heat exchange device may be applied to the main heat exchanger 4 or a combustion device having both heat exchangers. In some cases, it may be applied to both heat exchangers.

  Furthermore, although the said description showed the example applied to a water heater, the combustion apparatus of this invention is not restricted to a water heater, The bath water heater and the composite water heater provided with the function of both a water heater and a bath water heater are shown. You may apply.

  Furthermore, the combustion apparatus of the present invention only needs to have a heat exchange device having the configuration of the present invention. For example, the combustion apparatus may be an apparatus having an oil combustion burner, or a gas engine or gas turbine other than the burner 1. It is good also as a combustion apparatus provided with suitable combustion means, such as a combustor and a fuel cell.

  Furthermore, the heat exchange device may be incorporated in the combustion device, or may be appropriately disposed as necessary as a device separate from the combustion means.

  Furthermore, the heat receiving fluid flowing in the pipe line of the heat exchange device may be water as in the above-described embodiment, or may be a fluid other than water (for example, air).

It is explanatory drawing which shows typically the one reference example of the heat exchange apparatus which concerns on this invention. It is a graph which shows the water pressure loss suppression effect of the above-mentioned reference example compared with the conventional example. It is a section explanatory view showing typically an example of one embodiment of a heat exchanging device concerning the present invention. It is a graph which shows the thermal efficiency improvement effect of the said embodiment compared with a prior art example. It is a graph which shows the apparatus compactization of the said embodiment compared with a prior art example. They are side surface explanatory drawing (b) which shows typically other embodiment of the heat exchange apparatus which concerns on this invention, and side explanatory drawing (a) which shows the other reference example typically . Side explanatory views (b) and (d) schematically showing still other embodiments of the heat exchange device according to the present invention, and side explanatory views (a) and (c) schematically showing other reference examples. It is. It is sectional explanatory drawing which shows typically the form of the gas distribution path in the further embodiment of the heat exchange apparatus which concerns on this invention. It is sectional explanatory drawing which shows typically the form of the gas distribution path in the further embodiment of the heat exchange apparatus which concerns on this invention. It is a perspective explanatory view showing typically the connection form of the heat receiving pipe line in the embodiment of the heat exchange device according to the present invention. It is explanatory drawing of a bellows-shaped heat receiving pipe line. It is explanatory drawing which shows an example of a combustion apparatus typically. It is explanatory drawing which shows the example of the conventional heat exchange apparatus. It is a schematic diagram for demonstrating the flow of the water and combustion gas in the heat exchange apparatus shown in FIG. It is side surface explanatory drawing which shows the other example of the conventional heat exchange apparatus. It is explanatory drawing which shows typically the modification of the conventional heat exchange apparatus with (a) perspective view, (b) side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Burner 2 Gas distribution path 3 Heat receiving pipe 4 Main heat exchanger 5 Combustion fan 6 Latent heat recovery heat exchanger 7 Heat receiving pipe group 15 Turn-back part 16, 17 Header 19 Branching part 21 Merge part

Claims (8)

  A heat exchange device that is provided in a gas flow path through which combustion gas flows and recovers the heat of the combustion gas, and is arranged in a manner in which the combustion gas flows in a vertically stacked manner in a plurality of stages. A heat receiving pipe group is provided, and each stage of the heat receiving pipe group is arranged in a direction in which straight heat receiving pipes through which the heat receiving fluid that receives the heat of the combustion gas passes across the passage through which the combustion gas flows with a space therebetween. A plurality of pipe connection means are arranged in the direction in which the combustion gas flows on both end sides of the plurality of the heat reception pipes arranged side by side in the plurality of heat reception pipe groups. One end side of the passage and one end side pipe connecting means on the other end side constitute pipe connecting means on the heat receiving fluid introduction side, and the pipe on the heat receiving fluid introduction side Arranged on one end side and the other end side of the heat receiving pipe by a plurality of heat receiving pipes from the communication means A continuous communication flow path of the heat receiving pipe that is advanced to the pipe connection means of the final connection destination located on the other end side of the arrangement of the pipe communication means via the communication of the pipe communication means alternately formed, The pipe connection means at the final connection destination is the pipe connection means on the outlet side of the heat receiving fluid, and the heat receiving fluid supplied from the outside without being heated by the heat of combustion is branched into a plurality of heat receiving pipes at each stage. The heat receiving fluid that has passed through the heat receiving pipe group of each stage is collectively introduced into the pipe communication means on the heat receiving fluid introduction side of the path group, and the heat receiving fluid outlet pipe of each stage of the heat receiving pipe group It has the structure which joins in the fluid confluence | merging part connected to the path | route connection means, and derives | leads-out collectively, A partition member is provided between the heat receiving pipe line groups of each said stage, and passes the heat receiving pipe line group of each stage The gas distribution path of the combustion gas is divided, and the gas distribution path is the gas distribution path of the lower heat receiving pipe group. A return portion is provided for returning the introduced combustion gas to the gas flow path of the heat receiving pipe line group on the upper stage, and the combustion gas is sequentially introduced from the gas flow path of the lower heat receiving pipe line group to the upper stage. A heat exchanging apparatus characterized by being configured to be discharged from the gas flow path of the uppermost heat receiving pipe line group through the gas flow path of the heat receiving pipe line group. The pipe connection means on the heat receiving fluid introduction side of the heat receiving pipe group of each stage is constituted by one common pipe communication means, and the pipe communication means on the outlet side of the heat receiving fluid of the heat receiving pipe group of each stage is also included. The heat receiving fluid that is constituted by one common pipe communication means and is supplied from outside without being heated by the heat of combustion is introduced into the one common pipe communication means and introduced by the pipe communication means. The heat receiving fluid is distributed and supplied to the heat receiving pipes of the heat receiving pipe group of each stage, and the heat receiving fluid that has passed through the heat receiving pipes of each stage is joined by the common pipe communication means on the outlet side of the heat receiving fluid. 2. The heat exchange device according to claim 1 , wherein the heat exchange device is derived from the pipe communication means. The heat receiving pipe line group has a two-stage structure, and the flow path of the heat receiving pipe line of each stage of the heat receiving pipe line group communicates with pipe connecting means arranged on one end side and the other end side of the heat receiving pipe line. The heat receiving fluid introduction side pipe communicating means is disposed on the combustion gas inlet / outlet side with respect to the heat exchange device, and the heat receiving fluid outlet side pipe is formed. 3. The heat exchange device according to claim 2, wherein the path communication means is arranged on the side of the folded portion where the combustion gas is turned back to the upper heat receiving pipe line group through the lower heat receiving pipe line group. The heat exchange device according to claim 2 or 3, wherein the plurality of stages of gas flow paths are formed such that the path diameters are smaller for each stage toward the exhaust side of the combustion gas. The heat exchange device according to any one of claims 1 to 4 , wherein the heat receiving pipe line is a bellows pipe having irregularities formed in a bellows shape along a longitudinal direction. The heat exchange device according to any one of claims 1 to 5 , wherein the heat exchange device is a latent heat recovery heat exchange device that recovers the latent heat of the combustion gas. A combustion apparatus comprising the heat exchange device according to any one of claims 1 to 6 . 8. The combustion apparatus according to claim 7, wherein the heat receiving fluid is water, and has a hot water supply function of passing water through a heat exchange device to create hot water and supplying hot water to a hot water supply destination.

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