JP2022029331A - Heat exchange device and manufacturing method of heat exchange device - Google Patents

Abstract

To provide a heat exchange device capable of effectively coping with a large amount of drainage while achieving extremely high heat efficiency.SOLUTION: In a heat exchange device 4 composed of a plurality of heat exchangers, the plurality of heat exchangers include a primary heat exchanger 2 and a secondary heat exchanger 3 in which heat exchange elements 1a and 1b composed of a tubular member 10 for circulating a first heat exchange medium C inside, and circulating a second heat exchange medium D outside are erected vertically in the same arrangement. The secondary heat exchanger 3 is provided above the primary heat exchanger 2.SELECTED DRAWING: Figure 2

Description

The present invention relates to a heat exchanger composed of a plurality of heat exchangers and a method for manufacturing the same.

A latent heat recovery type heat exchanger that recovers latent heat contained in combustion exhaust gas and uses it for heating is known (see, for example, Patent Documents 1 to 3).
A water heater, which is an example of a latent heat recovery type heat exchanger, will be described with reference to FIG.
As shown in FIG. 21, this type of water heater is also referred to as an integrated heat exchanger that combines a primary heat exchanger and a secondary heat exchanger, and is generally a secondary heat directly above the primary heat exchanger. The configuration is such that an exchanger is installed.
Immediately below the heat exchanger (primary heat exchanger), a combustor capable of discharging high-temperature (about 1500 ° C.) combustion exhaust gas is provided, and the primary heat exchanger dissipates the exhaust heat (explicit heat) of the combustion exhaust gas. The water is heated by collecting it. Through this heat recovery, the combustion exhaust gas at about 200 ° C. is discharged toward the secondary heat exchanger.
The secondary heat exchanger heats water by recovering both the apparent heat of the combustion exhaust gas that has passed through the primary heat exchanger and the latent heat (condensation heat when the steam is condensed) contained in the combustion exhaust gas.
As for the water heater as a whole, first, the supplied water is supplied to the secondary heat exchanger, where the latent heat of the combustion exhaust gas is recovered and preheated, and then this preheated water exchanges the primary heat. There is a step of supplying to the vessel and recovering the apparent heat of the combustion exhaust gas to heat it, and the supplied water is discharged as hot water through these two steps.
As described above, the integrated heat exchanger realizes a thermal efficiency of about 95% by recovering latent heat from the combustion exhaust gas.
Therefore, the heat efficiency is excellent and the energy saving effect is high as compared with a water heater consisting only of a primary heat exchanger, which has a heat efficiency of about 80% (also referred to as heat exchange efficiency).

Japanese Patent No. 5656423 Japanese Patent No. 5742044 Japanese Patent No. 5306909

By the way, as conventional heat exchangers, those using combustion exhaust gas generated when petroleum-based fuel is burned have been widely used.
Since petroleum-based fuel contains a sulfur component, the sulfur component chemically changes to sulfur oxide (SOx) during combustion and is absorbed by the high-temperature steam generated during combustion, resulting in strong acidity. Combustion exhaust gas containing steam is generated.
This strongly acidic water vapor becomes strongly acidic acid dew water (condensed water) by dew condensation (condensation), but since this condensed water is strongly acidic, it may cause acid corrosion of chimneys and surrounding metal equipment. Become.
To deal with such problems, measures have generally been taken to prevent cooling to a temperature below the acid dew point (about 180 ° C.) (do not recover latent heat), that is, to prevent the generation of condensed water as much as possible.
On the other hand, in recent years, the use of hydrocarbon fuels such as LNG and LPG has been recommended as an alternative fuel to petroleum fuels from the viewpoint of environmental destruction and international conservation of the global environment.
Since LNG and LPG do not contain sulfur components, strongly acidic condensed water is not produced.
Therefore, when using a hydrocarbon fuel, it is considered unnecessary to take the above measures, and by doing so, heat can be recovered from the combustion exhaust gas as much as possible, and the thermal efficiency can be maximized.

However, another problem arises when the heat is recovered (cooled) as much as possible from the combustion exhaust gas of the hydrocarbon fuel.
This problem will be described with reference to the graph of FIG.
FIG. 22 is a graph showing changes in the amount of heat of combustion exhaust gas and the amount of acidic dew water (condensed water amount) with respect to the exhaust gas temperature.
As shown in this graph, when the combustion exhaust gas temperature is cooled to 60 ° C. or lower, the generation of condensed water becomes remarkable. That is, the lower the temperature of the combustion exhaust gas in an attempt to recover the latent heat as much as possible, the larger the amount of condensed water generated.
Therefore, in order to recover as much heat as possible from the combustion exhaust gas, it is necessary to appropriately discharge the condensed water (drain) generated in a large amount in the secondary heat exchanger.
As a specific example, a drain treatment method in a conventional integrated heat exchanger in which a secondary heat exchanger made of a serpentine SUS pipe (stainless steel pipe) is provided above the primary heat exchanger will be described.
For example, a method is known in which the SUS pipe of a secondary heat exchanger is tilted so that condensed water condensed on the surface of the SUS pipe is transmitted to the end and collected and discharged.
This method works well for conventional integrated heat exchangers where the latent heat recovery temperature is 50 ° C. or higher and therefore the amount of condensed water generated is very small.
However, in this method, it is not possible to transmit all the condensed water generated in a large amount to the end portion, and there arises a problem that the condensed water falls downward to some extent on the way.
Specifically, there is a risk of reducing the efficiency of heat recovery in the primary heat exchanger and adversely affecting the combustion reaction such as incomplete combustion in the combustor.
Further, it is conceivable to provide a saucer below the SUS pipe and discharge the condensed water collected in the saucer to the outside by a pipe or the like.
However, with this method, the saucer may obstruct the supply of combustion exhaust gas to the SUS pipe, reduce the thermal efficiency (recovered heat amount) in the secondary heat exchanger, and eventually reduce the thermal efficiency of the entire heat exchanger. In addition, as the amount of heat recovered increases, the heat transfer surface needs to be made longer, so that the size is increased.
Further, there is known a device in which a combustor is arranged in an upper stage, a primary heat exchanger is arranged in a middle stage, and a secondary heat exchanger is arranged in a lower stage.
According to such a device, the condensed water generated in the secondary heat exchanger falls below the condensed water due to gravity, so that the primary heat exchanger and the combustor are not adversely affected.
However, it is a natural phenomenon that the combustion exhaust gas rises and convects due to buoyancy, and when a mechanism / structure that opposes such a natural phenomenon is adopted, the temperature difference (buoyancy) between the flame temperature and the surrounding air is overcome. Natural ventilation unnecessarily complicates the structure, for example, the chimney height is required to be higher than the combustor of the water heater.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat exchange device capable of effectively treating a large amount of drainage in exchange for achieving extremely high thermal efficiency.

The heat exchange device according to the present invention is a heat exchange device composed of a plurality of heat exchangers, in which the first heat exchange medium is circulated internally in the plurality of heat exchangers, and the second heat exchange medium is used. A heat exchange element composed of a tubular member for circulating the heat to the outside includes a first heat exchanger and a second heat exchanger vertically erected in the same arrangement, and the first heat exchanger is described above. The second heat exchanger is provided above the above.
That is, the heat exchanger of the present invention is an integrated heat exchanger in which a second heat exchanger (secondary heat exchanger) is coupled above the first heat exchanger (primary heat exchanger), respectively. In the heat exchanger, heat exchange elements made of tubular members are provided in the same arrangement in a vertically erected manner.
Thereby, in the heat exchanger of the present invention, each heat exchange element in the second heat exchanger is arranged above each heat exchange element in the first heat exchanger.
Further, as a result, in the heat exchanger of the present invention, the first heat exchange medium (combustion exhaust gas) discharged from the combustor is exchanged with the inside of each heat exchange element in the first heat exchanger and the second heat exchange. The second heat exchange medium (water) is circulated through the inside of each heat exchange element in the vessel in a series, while the second heat exchange medium (water) is circulated outside the heat exchange element in the second heat exchanger, and then the first heat is circulated. It is distributed to the outside of the heat exchange element in the exchanger.
Inside the tubular member of each heat exchange element, a collision plate arranged so as to be inclined with respect to the axis of the tubular member is provided.
As a result, a high heat transfer coefficient can be realized by the collision heat transfer of the first heat exchange medium to the collision plate, and therefore, high heat efficiency can be realized in each heat exchanger provided with many heat exchange elements. Can be done.
That is, the first heat exchanger efficiently recovers the exhaust heat (emergent heat) of the high-temperature combustion exhaust gas generated by the combustion (oxidation) reaction in the combustor, while the second heat exchanger is the first. It is possible to efficiently recover both the actual heat of the combustion exhaust gas that has passed through the heat exchanger and the latent heat (condensation heat when the steam is condensed) contained in the combustion exhaust gas.
Therefore, according to the heat exchange device of the present invention, the amount of heat generated when the fuel burns can be recovered as much as possible as a high calorific value (total heat amount of fuel combustion heat + steam condensation heat), and as a result, An extremely high thermal efficiency of 97% can be achieved.
The basis for calculating the thermal efficiency will be described later.

Further, in the heat exchange device of the present invention, a plate-shaped member is provided between the first heat exchanger and the second heat exchanger, and the plate-shaped member is located at the installation position of the heat exchange element. It is characterized in that an opening is provided in the corresponding portion and a dam portion that surrounds the opening in a wall shape is provided.
That is, a drainage receiving plate for receiving a large amount of condensed water generated in each heat exchange element (tubular member) in the second heat exchanger is provided, and the drainage receiving plate is provided with heat in the second heat exchanger. An opening is provided between the inside of the exchange element and the inside of the heat exchange element in the first heat exchanger so that the first heat exchange medium can flow in a series.
In addition, by providing a wall-shaped dam around the opening, condensed water condensed on the inner surface of the tubular member of each heat exchange element in the second heat exchanger is collected without leaking downward, while convection heat and evaporation are performed. The amount of condensed water can be reduced by evaporation by heat.
Therefore, in exchange for recovering (cooling) heat as much as possible from the combustion exhaust gas, a large amount of drain generated can be smoothly processed without affecting the thermal efficiency and the combustion reaction.

According to the heat exchange device of the present invention, it is possible to effectively treat a large amount of drain while achieving extremely high thermal efficiency.

(A) shows a front perspective view of the heat exchange device of the present invention, and (b) shows a rear perspective view of the heat exchange device of the present invention. The exploded view of the heat exchange apparatus of this invention is shown. (A) shows a perspective view of a group of heat exchange elements, and (b) shows an enlarged view of an X1 portion of (a). (A) shows the plan view of the heat exchange element group, and (b) shows the enlarged view of the X2 part of (a). It is an external view of a drainage receiving plate (including a drainage pipe), (a) shows a front view, (b) shows a plan view, and (c) shows a side view. It is sectional drawing of the heat exchange element. The perspective view of the heat exchange element which concerns on the 1st example is shown. (A) shows a schematic front view of the heat exchange element shown in FIG. 7, and (b) shows a schematic cross-sectional view of (a). (A) shows a perspective perspective view of the heat exchange element according to the second example, (b) shows a perspective side view, and (c) shows a front view. FIG. 9 is a perspective view of a heat exchange element cut along the AC-AC line of FIG. 9 (c). (A) shows the side view of the collision plate and the U-shaped groove member constituting the heat exchange element which concerns on the 2nd example, (b) shows the top view, and (c) shows the front view. The figure for demonstrating the flow of the 2nd heat exchange medium in a heat exchange apparatus is shown. It is a figure for demonstrating the flow of the 1st heat exchange medium in a heat exchange apparatus, (a) shows the plan view of the heat exchange apparatus, (b) is along the AA-AA line of (a). The cross-sectional view is shown, and (c) is an enlarged schematic view of (b). It is a chart showing the latent heat recovery performance (preheating performance) in the heat exchanger of the present invention, (a) shows a comparison of various exhaust gas measured values in a secondary heat exchanger with a commercially available product, and (b) is two. The comparison of various water supply measurement values in the next heat exchanger with the commercially available products is shown. (A) shows a perspective view of a drainage receiving plate, (b) shows an enlarged view of the X3 portion of (a), and (c) shows the schematic sectional view of the drainage receiving plate. (A) shows a perspective view of a single-ended tube expansion type heat exchange element, (b) shows an internal plan view of a heat exchanger provided with the heat exchange element of (a), and (c) is (b). ) Is shown. It is a figure which shows the arrangement method of the heat exchange element using a tube expansion part. (A) shows a perspective view of a heat exchange element of a tube expansion type at both ends, (b) shows an internal plan view of a heat exchanger provided with the heat exchange element of (a), and (c) is (b). ) Is shown. (A) shows a perspective view of a heat exchange element having both ends and a central expansion tube, (b) shows an internal plan view of a heat exchanger equipped with the heat exchange element of (a), and (c) shows an internal plan view. The side view of (b) is shown. (A) shows a perspective view of a straight type heat exchange element, (b) shows an internal plan view of a heat exchanger provided with the heat exchange element of (a), and (c) is (b). The side view of is shown. A schematic explanatory diagram of a conventional integrated heat exchanger is shown. The graph which shows the relationship between the combustion exhaust gas temperature and the amount of acidic dew water (the amount of condensed water) with respect to the exhaust gas temperature is shown.

Hereinafter, embodiments of the heat exchange device 4 of the present invention will be described with reference to the drawings.
1A shows a front perspective view of the heat exchange device 4 of the present invention, and FIG. 1B shows a rear perspective view of the heat exchange device 4 of the present invention. FIG. 2 shows an exploded view of the heat exchange device 4 of the present invention.
As shown in these figures, the heat exchanger 4 of the present invention is an integrated heat exchange composed of a plurality of heat exchangers in which the secondary heat exchanger 3 is provided directly above (above) the primary heat exchanger 2. It is a device.
The heat exchanger 4 may be composed of three or more heat exchangers.
Further, in the present embodiment, the primary heat exchanger 2 is described as an example of the "first heat exchanger" of the present invention, and the secondary exchange 3 is the "second heat exchanger" of the present invention. This will be described as an example, but this is not the case.
For example, when the heat exchanger 4 is composed of three or more heat exchangers, the heat exchanger whose relative position is lower corresponds to the "first heat exchanger" and its relative position is upward. The heat exchanger of the above corresponds to the "second heat exchanger".
Further, in the present embodiment, the heat exchanger 4 will be described assuming that it is mainly applied to a water heater, but it can also be applied as a device other than the water heater.
Further, in the present embodiment, the "first heat exchange medium C" assumes the combustion exhaust gas discharged from the combustor, and the "second heat exchange medium D" is the water supplied to the water heater. However, a medium other than the combustion exhaust gas may be used as the "first heat exchange medium C", or a medium other than water may be used as the "second heat exchange medium D".

The primary heat exchanger 2 includes a heat exchange element group 21 which is an aggregate of a predetermined number of heat exchange elements 1 (the one in the primary heat exchanger 2 is particularly referred to as “heat exchange element 1a”), and each heat exchange element 1a. A base plate 27 that can be fixed in a predetermined arrangement, side plates 25 (front side plates 25a and rear side plates 25b) provided on the front and rear sides of the heat exchange element group 21, and heat exchange element group 21. It is composed of a manifold 26 provided on the left side and the right side (a manifold 26a on the left side and a manifold 26b on the right side).
The secondary heat exchanger 3 is a heat exchange element group 31 which is an aggregate of the same number of heat exchange elements 1 as the heat exchange elements 1a (the thing in the secondary heat exchanger 3 is particularly referred to as “heat exchange element 1b”). A base plate 37 to which each heat exchange element 1b can be fixed in the same arrangement as the heat exchange element 1a, and side plates 35 (front side plates 35a and rear side) provided on the front and rear sides of the heat exchange element group 31. It is composed of a side plate 35b) and manifolds 36 (manifold 36a on the left side and manifold 36b on the right side) provided on the left and right sides of the heat exchange element group 31.
The heat exchange element 1a in the primary heat exchanger 2 and the heat exchange element 1b in the secondary heat exchanger 3 are both composed of the same tubular member 10, and the tubular members 10 are vertically erected in the same arrangement. It is provided in an embodiment (see FIG. 2).
As described above, the primary heat exchanger 2 and the secondary heat exchanger 3 are the same heat exchangers having the same components and structure.

The heat exchange elements 1a and 1b will be described with reference to FIGS. 3 and 4.
Since the heat exchange element 1a and the heat exchange element 1b differ only in the length of the pipe (longitudinal portion) and have the same structure, installation mode, etc. (see FIG. 2), FIGS. 3 and 4 show heat. It is referred to as a common drawing of the exchange element 1a and the heat exchange element 1b.
As shown in FIGS. 3 and 4, the heat exchange elements 1a and 1b are composed of a tubular member 10 made of metal (SUS or the like) having a square end opening and a square cross section and a hollow inside. The heat exchange element groups 21 and 31 are formed as an aggregate in which a predetermined number of these are arranged.
In the present embodiment, the heat exchange elements 1a and 1b (tubular members 10) are erected in an array of 32 (front-back direction) x 44 (left-right direction), whereby heat exchange in a rectangular shape in a plan view is performed. It forms the element groups 21 and 31.
The heat exchange elements 1a and 1b are arranged so that the adjacent tubular member 10 and the tubular member 10 are separated from each other with a slight gap, whereby the adjacent tubular member 10 and the tubular member 10 are arranged. The gap space formed between them is configured as a flow path of the second heat exchange medium.
Further, the heat exchange elements 1a and 1b are arranged in parallel (series) by arranging the tubular members 10 at the same position along the front-rear direction, but adjacent tubular members are arranged along the left-right direction. The members 10 are arranged in a staggered manner by changing the arrangement position.
With such a staggered arrangement, the flow path of the second heat exchange medium from the left to the right can be made to bend alternately instead of a straight line to lengthen the flow path.
According to such a flow path, the second heat exchange medium D can be circulated between the adjacent tubular members 10 and the tubular members 10 while contacting the outer surfaces thereof over a wide range for a long time. See the arrows in FIGS. 3 (b) and 4 (b)).
Therefore, while the first heat exchange medium C (combustion exhaust gas) is circulated inside each tubular member 10, the second heat exchange medium D (water) is circulated in this flow path (outside the tubular member 10). In this case, the first heat exchange medium C (combustion exhaust gas) can be cooled as much as possible through each tubular member 10, and in exchange for this, the heat (exhaust) of the first heat exchange medium C can be cooled. The heat) can be recovered (transferred) to the second heat exchange medium (water) as much as possible.
The number of heat exchange elements 1a and 1b can be determined according to the required exchange heat amount (recovered heat amount) and the like, and the heat exchange elements 1a and 1b can be arranged in various arrangement modes. ..
Therefore, the heat exchangers 2 and 3 and the heat exchange device 4 having various performances, specifications and designs according to the number and arrangement of the heat exchange elements 1a and 1b can be easily designed and manufactured.

Further, the heat exchange elements 1a and 1b are arranged so that the distance between the adjacent tubular members 10 and the tubular members 10 is uniform.
By making the separation interval W of the adjacent heat exchange elements 1 uniform in this way, the occurrence of heat transfer unevenness due to the variation in the interval is suppressed, and the heat exchange element 1 flows outside the tubular member 10. An even flow of the heat exchange medium of 2 is formed.
Further, if the separation interval W of the adjacent heat exchange elements 1 is made uniform, the exchange heat amount that can be provided can be calculated according to the separation interval W. Therefore, the separation interval W is determined according to the required exchange heat amount. be able to.

As shown in FIGS. 2 and 3, the base plates 27 and 37 are metal (SUS or the like) base members laid on the upper parts of the heat exchange element groups 21 and 31, and are specifically arranged vertically. It is a plate-shaped member coupled to the upper part of each heat exchange element 1a, 1b.
The base plates 27 and 37 are provided with openings 27a and 37a into which the end portions (upper ends) of the tubular members 10 can be fitted in the portions corresponding to the installation positions of the heat exchange elements 1a and 1b.
Therefore, the base plates 27 and 37 can be tightly joined by brazing or the like in a state where the openings 27a and 37a are fitted to the upper ends of the tubular members 10 of the heat exchange elements 1a and 1b.
According to such base plates 27 and 37, the heat exchange elements 1a and 1b can be firmly fixed.
Specifically, the heat exchange elements 1a and 1b receive, for example, the flow of the second heat exchange medium (water) from the outside, and the base plates 27 and 37 are responsible for the pressure resistance and impact resistance related to this flow. There is.
Further, since the openings 27a and 37a corresponding to the arrangement of the heat exchange elements 1a and ab are provided in advance, a uniform separation interval W can be obtained simply by fitting the heat exchange elements 1a and 1b into the openings 27a and 37a and joining them. The array in can be realized exactly.

In addition, the heat exchanger 4 is provided with a drainage receiving plate 5 between the primary heat exchanger 2 and the secondary heat exchanger 3.
As shown in FIG. 5, the drainage receiving plate 5 is provided with an opening 5a in a portion corresponding to each of the heat exchange elements 1a and 1b.
Further, the heat exchanger 4 is provided with an exhaust cover 6 on the upper part of the secondary heat exchanger 3, an inlet header 71 on the upper part of the manifold 36a, an outlet header 72 on the lower part of the manifold 26a, and the manifold 36b and the manifold 26b. A U-shaped tube 73 is provided to connect the two (see FIGS. 1 and 2).

As described above, the heat exchange device 4 of the present invention is composed of a plurality of heat exchangers, and the first heat exchange medium C is circulated internally in the plurality of heat exchangers, and the second heat exchange medium is used. A heat exchange element 1 composed of a tubular member 10 for circulating D to the outside includes a primary heat exchanger 2 and a secondary heat exchanger 3 vertically erected in the same arrangement, and the primary heat exchanger 2 is included. The secondary heat exchanger 3 is provided above the above.
That is, the heat exchanger 4 of the present invention can be realized by accurately overlapping and integrally connecting heat exchangers having the same configuration and the same shape.
Therefore, the heat exchanger 4 of the present invention can be manufactured only by going through a step of providing a heat exchanger having the same configuration above the heat exchanger.

Immediately below the heat exchanger 4 (primary heat exchanger 2), a combustor (not shown) that can use hydrocarbon fuels such as LPG and LNG as fuel is arranged.
As a result, the high-temperature combustion exhaust gas (first heat exchange medium) generated by the combustion reaction in the combustor is discharged above the combustor, that is, toward the primary heat exchanger 2.
It is also possible to install a fan (not shown) for evenly sending the combustion exhaust gas with a constant air volume.
It is also possible to use a combustor that can use a fuel other than a hydrocarbon fuel such as a petroleum fuel.

With reference to FIG. 6, the positional relationship between the heat exchange element 1a and the heat exchange element 1b and the flow path of the first heat exchange medium C in the heat exchange device 4 will be described.
FIG. 6 is a schematic cross-sectional view of the heat exchange element 1a and the heat exchange element 1b.
The heat exchange elements 1a and 1b in the heat exchange device 4 of the present invention basically provide an inclined collision plate 11 inside the tubular member 10 (see FIGS. 4, 7 to 11 and the like). ), Here, for the sake of simplicity, the illustration regarding the collision plate 11 will be omitted.
As shown in FIG. 6, each heat exchange element 1a and each heat exchange element 1b are vertically erected, and each heat exchange element 1b is arranged directly above each heat exchange element 1a.
Specifically, the opening at the upper end of the heat exchange element 1a (second opening end) and the opening at the lower end of the heat exchange element 1b (first opening end) coincide with each other in the horizontal direction and face each other in the vertical direction. The heat exchange elements 1a and 1b are provided so that the positional relationship is established.
Further, a base plate 27 that covers the entire heat exchange element 1a is provided on the upper portion of each heat exchange element 1a, and an opening 27a is provided in a portion of the base plate 27 corresponding to the installation position of each heat exchange element 1a. There is.
Further, a drainage receiving plate 5 that covers the entire heat exchange elements 1a and 1b is provided between the heat exchange element 1a and the heat exchange element 1b, and the heat exchange elements 1a and 1b of the drainage receiving plate 5 are installed. An opening 5a is provided in the portion corresponding to the position.
Further, a base plate 37 that covers the entire heat exchange element 1b is provided on the upper portion of the heat exchange element 1b, and an opening 37a is provided in a portion of the base plate 37 corresponding to the installation position of each heat exchange element 1b. ..
That is, the base plates 27 and 37 and the drainage receiving plate 5 are provided so as not to block the openings at both ends of the tubular members 10 of the heat exchange elements 1a and 1b.
Therefore, as shown in FIG. 6, the first heat exchange medium C (combustion exhaust gas) heading upward from the bottom is transferred to the inside of each heat exchange element 1a (tubular member 10) in the primary heat exchanger 2 and the secondary heat. The inside of each heat exchange element 1b (tubular member 10) in the exchanger 3 can be circulated in a series.
That is, the heat exchanger 4 of the present invention is configured such that the primary heat exchanger 2 and the secondary heat exchanger 3 having the same configuration are vertically overlapped with each other, whereby the heat exchange element 1a in the primary heat exchanger 2 is formed. And the heat exchange element 1b in the secondary heat exchanger 3 both have a positional relationship in which a tubular member 10 having a hollow inside is vertically erected and vertically overlapped with each other. A series of internal spaces form a flow path for the combustion exhaust gas penetrating in the vertical direction.

Two examples of the heat exchange element 1 will be described in detail with reference to FIGS. 7 to 11.

(First example of heat exchange element)
The heat exchange element according to the first example will be described with reference to FIGS. 7 to 8.
As shown in FIGS. 7 and 8, the heat exchange element 1 of the first example is a tubular member for circulating the first heat exchange medium C inside and the second heat exchange medium D to the outside. A collision plate 11 is provided inside the tubular member 10 so as to be inclined with respect to the axis O of the tubular member 10.

The tubular member 10 has a first opening end 12 and a second opening end 13, and has a square outer shape in a cross section orthogonal to the axis O.
The cross section of the tubular member 10 orthogonal to the axis O may have an outer shape of a regular polygon such as an equilateral triangle and a regular hexagon.
Further, the cross section may be circular or rectangular.
SUS is used as the material of the tubular member 10, but aluminum or copper can also be used, for example, depending on the nature of the first heat exchange medium flowing inside.

The collision plate 11 has both end edges of the collision plate 11 in the maximum inclination direction S with respect to the axis O, that is, a first end edge 11e inclined toward the first opening end 12 side and a second end inclined toward the second opening end 13 side. The edges 11f are in contact with the inner surfaces 10a and 10b of the tubular member 10, respectively, while both end edges in the direction orthogonal to the maximum inclination direction S, that is, the side edge edges 11c and 11d are the inner surfaces 10c and 10d of the tubular member 10, respectively. It is separated.

Next, a flow method of the first heat exchange medium C flowing inside the tubular member 10 from the first opening end 12 to the second opening end 13 will be described.
As shown in FIGS. 7 and 8, the first heat exchange medium C that has entered the tubular member 10 from the first opening end 12 of the tubular member 10 of the heat exchange element 1 collides with the inclined collision plate 11. A low-pressure vortex is formed on the surface 11a of the collision plate 11 to form a collision jet A which is a flow adhering along the surface 11a of the collision plate 11. The collision jet A forms a velocity boundary layer very close to the collision plate 11, and a temperature boundary layer is formed above the velocity boundary layer. As a result, the heat exchange element 1 exhibits a high heat transfer coefficient with respect to the collision plate 11 due to the collision heat transfer to the collision plate 11 of the first heat exchange medium C.

Subsequently, the collision jet A of the first heat exchange medium continuously ejects from the gaps g on both sides of the collision plate 11 toward the second opening end 13 side, and the back surface 11b of the collision plate 11 is along the inner surface of the tubular member 10. It becomes a swirling flow B that wraps around to the side. The formation of the swirling flow B sustains the flow attached to the heat receiving surface, which is the inner surface of the tubular member 10 of the heat exchange element, and at the same time converts the first heat exchange medium into a unidirectional flow, thereby reducing the pressure. Form a swirling laminar flow that indicates loss. As a result, a high heat transfer coefficient is exhibited with respect to the inner surfaces 10a to 10d of the tubular member 10 of the heat exchange element 1.

Further, by arranging the drawing member 14 near the second opening end 13 of the tubular member 10, the cross-sectional area of the second opening end 13 of the tubular member 10 becomes smaller than the cross-sectional area of the first opening end 12. There is. This has the effect of reducing the inlet pressure loss and fixing the collision plate 11 arranged in the tubular member 10 by widening the cross-sectional area at the first opening end 12 of the inlet, and as a result, the heat transfer efficiency. The synergistic effect of the action of increasing the pressure loss and the action of reducing the pressure loss can be obtained.
In this example, an example in which the diaphragm member 14 is arranged to reduce the cross-sectional property of the second opening end 13 has been described, but the first opening end 12 has a shape that expands toward the tip. The cross-sectional area may be increased. In that case, the diaphragm member 14 may or may not be provided. Further, the cross-sectional area of the tubular member 10 may be gradually narrowed from the first opening end 12 to the second opening end 13.

As described above, since the heat exchange element 1 is provided with a mechanism for forming the inclined collision plate 11 and the swirling laminar flow inside the tubular member 10, the synergistic effect of the collision jet flow A and the swirling laminar flow causes the heat exchange element 1. Even if fins are not provided, low pressure loss can be realized together with high surface heat transfer on the inner surface of the heat exchange element 1.

(Second example of heat exchange element)
The heat exchange element according to the second example will be described with reference to FIGS. 9 to 11.
As shown in FIGS. 9 (a) and 9 (b), in the heat exchange element 101 of the second example, the first heat exchange medium C is circulated inside and the second heat exchange medium D is sent to the outside. A tubular member 110 having a substantially square cross-sectional shape for distribution and a collision plate 111 arranged inside the tubular member 110 so as to be inclined with respect to the axis O of the tubular member 110 are provided.
The tubular member 110 has a first opening end 112 that widens toward the tip and opens, and a second opening end 113 that forms the narrowed portion 110e.

As shown in FIG. 9C, in the heat exchange element 101 of the second example, the collision plate 111 is the first open end of both end edges 111e and 111f of the maximum inclination direction S of the collision plate 111 with respect to the axis O. The first edge 111e inclined to the 112 side is in contact with the inner surface 110a of the tubular member 110.
On the other hand, as shown in FIG. 9A, the collision plate 111 is separated from the inner surface 110b of the tubular member 110 at the second end edge 111f inclined toward the second opening end 113, and is in the maximum inclination direction S. Both side edges 111c and 111d in the orthogonal direction are also separated from the inner surfaces 110c and 110d of the tubular member 110, respectively.

As shown in FIGS. 10 and 11 (a) to 11 (c), the heat exchange element 101 is directed from the second end edge 111f and both side edges 111c and 111d of the collision plate 111 toward the second opening end 113. Further, a U-shaped groove member 15 extending along the axis O of the tubular member 110 is provided. The U-shaped groove member 15 is composed of a bottom surface portion 15b and both side surface portions 15c and 15d rising from the bottom surface portion 15b. The bottom surface portion 15a is continuous with the second end edge 111f of the collision plate 111, and the side surface portions 15c and 15d are continuous with both side edges 111c and 111d of the collision plate 111, respectively. Therefore, the collision plate 111 and the U-shaped groove member 15 are integrated.
Further, as shown in FIG. 11A, both side edges 15e of the side surface portions 15c and 15d of the U-shaped groove member 15 extending along the axis O of the tubular member 110 are from the first end edge 111e of the collision plate 111. Is also set down. That is, the first end edge 111e of the collision plate 111 protrudes from both side edges 15e.

As shown in FIG. 11C, the bottom surface portion 15b and the both side surface portions 15c and 15d of the U-shaped groove member 15 are formed with claw portions t protruding outward, respectively. As shown in FIG. 9C, the U-shaped groove member 15 and the collision plate 111 are positioned in the tubular member 110 with the claw portion t as a spacer. The claw portion t does not substantially affect the distribution of the first heat exchange medium C.

A U-shaped gap Gu is secured between the outer surfaces of the bottom surface portion 15b and the side surface portions 15c and 15d of the positioned U-shaped groove member 15 and the inner surfaces 110b, 110c and 110d of the tubular member 110, respectively. In this example, the outer surfaces of the bottom surface portion 15b, the side surface portions 15c, and the side surface portions 15d of the U-shaped groove member 15 are parallel to the inner surface 110b, the inner surface 110c, and the inner surface 110d of the tubular member 110, respectively.
As shown in FIGS. 9 (a), 9 (b) and 10, the U-shaped gap Gu is provided along the second end edge 111b and both side edges 111c and 111d of the collision plate 111 on the first opening end 112 side. The tubular member 110 is opened inside the tubular member 110, while the tubular member 110 is closed by the narrowed portion 110e on the side of the second opening end 113. As a result, the cross-sectional area of the second opening end 113 of the tubular member 110 is smaller than the cross-sectional area of the first opening end 112. Further, in this example, as shown in FIG. 9B, the end portion 15f of the U-shaped groove member 15 projects outward from the second opening end 113 of the tubular member 110.

Further, as shown in FIG. 9B, the side edges 15e extending along the axis O of the tubular member 110 and the first end edge 111e of the collision plate 111, respectively, of the side surface portions 15c and 15d of the U-shaped groove member 15. A band-shaped gap Gs extending with a constant width is secured between the tubular member 110 and the inner surface 100a in contact with the tubular member 110. Through the band-shaped gap Gs, the space inside the U-shaped gap Gu outside the U-shaped groove member 15 and the space inside the U-shaped groove member 15 communicate with each other.

Next, a flow method of the first heat exchange medium C flowing inside the tubular member 110 from the first opening end 12 to the second opening end 13 will be described.
As shown in FIGS. 9A to 9C, first, the first heat exchange medium C that has entered the tubular member 110 from the first opening end 112 of the tubular member 110 of the heat exchange element 101 is inclined. It collides with the collision plate 111 to form a low-pressure vortex on the surface 111a of the collision plate 111, and forms a collision jet flow A which is a flow adhering along the surface 111a of the collision plate 111. The collision jet A forms a velocity boundary layer very close to the collision plate 11, and a temperature boundary layer is formed above the velocity boundary layer. As a result, the heat exchange element 1 exhibits a high heat transfer coefficient with respect to the collision plate 11 due to the collision heat transfer to the collision plate 11 of the first heat exchange medium C.

Subsequently, the collision jet A of the first heat exchange medium C enters the U-shaped gap Gu and forms a flow attached to the heat receiving surface which is the inner surface of the tubular member 110 of the heat exchange element 101. Further, since the first heat exchange medium C that has entered the U-shaped gap Gu is closed on the second opening end 113 side of the U-shaped gap Gu, it is ejected from the band-shaped gap Gs to the inside of the U-shaped groove member 15. The swirling flow B wraps around the back surface 111b of the collision plate 111. The formation of the swirling flow B forms a swirling laminar flow showing low pressure loss by converting the first heat exchange medium C into a unidirectional flow. As a result, a high heat transfer coefficient is exhibited with respect to the inner surfaces 10a to 10d of the tubular member 110 of the heat exchange element 101.
In particular, in the heat exchange element 101 according to the second example, the cross-sectional area at the first opening end 112 on the inlet side is larger than the cross-sectional area at the second opening end 113 on the outlet side, so that the inlet pressure loss There is an effect of fixing the collision plate 111 that enters the inside, and as a result, a synergistic effect of an action of increasing the heat transfer efficiency and an action of reducing the pressure loss can be obtained.

In FIGS. 9 (a) and 9 (b), in order to facilitate understanding of the drawings, the first heat exchange medium C passing through the gap on one side surface portion 15d side of the U-shaped gap Gu. Only the flow is shown, and the flow of the first heat exchange medium C passing through the gap on the other side surface portion 15c side is omitted. Actually, as shown in FIG. 9C, the first heat exchange medium C that has entered the U-shaped gap Gu is roughly divided into two hands and advances through the gaps on both side surface portions 15c and 15d, respectively, and the U-shaped groove The strip-shaped gaps Gs on both side edges 15e of the member 15 flow into the inside of the U-shaped groove member 15, respectively, and form two large swirling flows in the U-shaped groove member 15.

As described above, since the heat exchange element 101 is provided with a mechanism for forming the inclined collision plate 111 and the swirling laminar flow inside the tubular member 110, the synergistic effect of the collision jet flow A and the swirling laminar flow causes the heat exchange element 101 to form a swirling laminar flow. Even if fins are not provided, low pressure loss can be realized together with high surface heat transfer on the inner surface of the tubular member 110 of the heat exchange element 101.

Next, the function of the heat exchanger 4 as a water heater will be described with reference to FIGS. 12 and 13.
The flow of water D (second heat exchange medium D) will be described with reference to FIGS. 12 and 13 (b).
First, when water is supplied to the inlet head 71, the supplied water D flows into the inside from the left side of the secondary heat exchanger 3 by the induction of the manifold 36a, and is between the heat exchange element 1b and the heat exchange element 1b. It advances toward the right side while flowing through the gap space of.
The water D that has passed through the inside of the secondary heat exchanger 3 and reached the manifold 36b is guided to the inside of the primary heat exchanger 2 via the U-shaped pipe 73 and the manifold 26b.
The water D flowing in from the right side of the primary heat exchanger 2 travels toward the left side while flowing in the gap space between the heat exchange element 1a and the heat exchange element 1a.
The water that has passed through the inside of the primary heat exchanger 2 and reached the manifold 26a is discharged from the outlet header 72.

Next, with reference to FIGS. 13 (b) and 13 (c), the flow of the combustion exhaust gas C (first heat exchange medium C) and the heat recovery in each of the heat exchangers 2 and 3 will be described.
It is assumed that the heat exchange element 1 (see FIGS. 7 to 8) according to the first example is applied as the heat exchange element 1a and the heat exchange element 1b.
However, the heat exchange element 101 according to the second example (see FIGS. 9 to 11) may be applied, or the heat exchange element 1 according to the first example and the heat exchange element 1 according to the second example may be applied in combination. You can also do it.
A combustor and a fan are provided directly under the heat exchanger 4 (not shown), and the high temperature (for example, 1500 ° C.) combustion exhaust gas C from the combustor is discharged toward the heat exchanger 4. do.
In the heat exchanger 4, the heat exchange element 1a in the primary heat exchanger 2 and the heat exchange element 1b in the secondary heat exchanger 3 are vertically overlapped with each other in a form in which a tubular member 10 having a hollow inside is vertically erected. It has a positional relationship, and a flow path of the combustion exhaust gas C penetrating in the vertical direction is formed by a series of internal spaces formed by the vertically overlapping tubular members 10.
Therefore, the combustion exhaust gas C enters the inside from below the heat exchanger 4, and passes through the inside of the primary heat exchanger 2 and the inside of the secondary heat exchanger 2.
After passing through the inside of the heat exchange device 4, the combustion exhaust gas C is discharged as exhaust gas from the exhaust port 61 of the exhaust cover 6.

(Flow and heat transfer of combustion exhaust gas in the primary heat exchanger)
As shown in FIG. 13 (c), in the primary heat exchanger 2, when the combustion exhaust gas C enters the inside of the tubular member 10 from the first opening end (lower end) 12 of each heat exchange element 1a (tubular member 10). It collides with the inclined collision plate 11.
As a result, the combustion exhaust gas C forms a low-pressure vortex on the surface 11a of the collision plate 11 and forms a collision jet A which is a flow adhering along the surface 11a of the collision plate 11 (see FIGS. 7 and 8). ..
Therefore, the heat exchange element 1a exhibits a high heat transfer coefficient with respect to the collision plate 11 due to the collision heat transfer of the combustion exhaust gas C to the collision plate 11.

The collision jet A is ejected from the gap g on both sides of the collision plate 11 toward the second opening end 13 side, and is a swirling flow B that wraps around the inner surface of the tubular member 10 of the heat exchange element 1a toward the back surface 11b side of the collision plate 11. Become. The formation of the swirling flow B sustains the flow attached to the heat receiving surface which is the inner surface of the tubular member 10 of the heat exchange element 1a, and at the same time, converts the combustion exhaust gas C into a unidirectional flow, thereby reducing the pressure loss. Form the swirling laminar flow shown.
As a result, a high heat transfer coefficient is exhibited with respect to the inner surfaces 10a to 10d of the tubular member 10 of the heat exchange element 1a (see FIGS. 7 and 8).
As described above, the heat transfer capacity of each heat exchange element 1a is promoted by the action of collision heat transfer and swirling laminar flow.

The swirling laminar flow B flows upward inside the tubular member 10 and is discharged upward from the second opening end (upper end) 13.

(Flow and heat transfer of combustion exhaust gas in the secondary heat exchanger)
In the secondary heat exchanger 3, the combustion exhaust gas C collides with the inclined collision plate 11 when entering the inside of the tubular member 10 from the first opening end (lower end) 12 of each heat exchange element 1b (tubular member 10). A collision laminar flow A is formed, and a swirling laminar flow B is formed based on the collision laminar flow A.
Therefore, even in the heat exchange element 1b, the heat transfer capacity is promoted by the action of collision heat transfer and swirling laminar flow.

The swirling laminar flow B flows upward inside the tubular member 10 and is discharged upward from the second opening end (upper end) 13.

(Flow of the entire water heater)
The water D supplied to the inlet header 71 first flows into the secondary heat exchanger 3 and recovers the latent heat and sensible heat of the combustion exhaust gas C in the process of flowing inside the secondary heat exchanger 3 (outside the heat exchange element 1b). Preheated with.
Specifically, the water D reaches the sensible heat of the combustion exhaust gas C and the combustion exhaust gas C that have passed through the primary heat exchanger 2 through the tubular member 10 while in contact with the outer surface of the tubular member 10 of the heat exchange element 1b. Recover the latent heat contained.
The flow path of the water D is formed by the gap space between the adjacent tubular members 10 and the tubular members 10 in the heat exchange element group 31 in which a large number of heat exchange elements 1b (tubular members 10) are vertically and horizontally arranged vertically and horizontally. By arranging the tubular members 10 in a staggered manner, the water D is formed so as to proceed while bending.
In the process, the water D flowing through such a flow path circulates while contacting the outer surfaces of a large number of tubular members 10 over a wide range for a long time, so that the combustion exhaust gas C can be generated through each tubular member 10. It can be cooled as much as possible (specifically, up to 40 ° C. or lower), and in exchange, the waste heat (latent heat and sensible heat) of the combustion exhaust gas C can be recovered to water D as much as possible.

The water D preheated by the secondary heat exchanger 3 is then heated by the primary heat exchanger 2.
Specifically, the water D recovers the sensible heat of the combustion exhaust gas C through the tubular member 10 while contacting the outer surface of the tubular member 10 of the heat exchange element 1a.
The flow path of the water D is formed by the gap space between the adjacent tubular members 10 and the tubular members 10 in the heat exchange element group 21 in which a large number of heat exchange elements 1a (tubular members 10) are vertically and horizontally arranged vertically and horizontally. By arranging the tubular members 10 in a staggered manner, the water D is formed so as to proceed while bending.
In the process, the water D flowing through such a flow path circulates while contacting the outer surfaces of a large number of tubular members 10 over a wide range for a long time, so that the combustion exhaust gas C can be generated through each tubular member 10. It can be cooled as much as possible (specifically, up to 160 to 200 ° C.), and in exchange, the waste heat (sensible heat) of the combustion exhaust gas C can be recovered to water D as much as possible.
In this way, the water D supplied to the heat exchanger 4 is preheated by the latent heat recovery in the secondary heat exchanger 3, and then heated by the sensible heat recovery in the primary heat exchanger 2 to become hot water. Water can be discharged from the outlet header 72.

FIG. 14 is a chart showing the experimental results regarding the latent heat recovery performance (preheating performance) in the heat exchanger 4 of the present invention, and FIG. 14A is a comparison of various exhaust gas measured values in the secondary heat exchanger 3 with commercially available products. (B) shows a comparison of various water supply measurement values in the secondary heat exchanger 3 with commercially available products.
It should be noted that each measured value shown in FIG. 14 is an actually measured value in a 50 KW class device.
Further, it is known that the commercially available product is a latent heat recovery type integrated heat exchange device similar to the heat exchange device 4 of the present invention, and its thermal efficiency is about 95% (value published by the manufacturer).
As shown in FIG. 14A, the heat exchanger 4 of the present invention and the commercially available product (conventional product) have substantially the same air volume and inlet temperature of the combustion exhaust gas in the secondary heat exchanger. The outlet temperature (39.2 ° C.) of the combustion exhaust gas of the heat exchange device 4 of the present invention can be significantly lower than the outlet temperature (91.9 ° C.) of a commercially available product, and the heat exchange device 4 of the present invention can be supplied. The amount of heat (1.95 kW) can be significantly higher than the amount of heat supplied (1.14 kW) of a commercially available product.
Therefore, as shown in FIG. 14 (b), the heat exchanger 4 of the present invention and the commercially available product have the same water supply amount and inlet temperature in the secondary heat exchanger 3, but the present invention. The outlet temperature (30.3 ° C.) of the water supply of the heat exchange device 4 can be significantly higher than the outlet temperature (28.8 ° C.) of a commercially available product, and the amount of latent heat recovered from the heat exchange device 4 of the present invention can be recovered. (2.07 kW) can be significantly (about twice) higher than the amount of heat recovered (1.04 kW) of a commercially available product.
From such experimental results, it is shown that the heat exchange device 4 of the present invention realizes extremely high thermal efficiency and is excellent in energy saving performance.

Hereinafter, the basis for calculating the thermal efficiency of the heat exchange device 4 of the present invention will be shown.
-Thermal efficiency of commercial products: 95% (value announced by the manufacturer)
-Commercial product heat loss: (50 / 0.95-50) KW = 2.63KW
-Recovered calorific value of commercial products: 1.04 KW (actual measurement value. See Fig. 14 (b))
-Recovered heat quantity of the apparatus of the present invention: 2.07 KW (actual measurement value. See FIG. 14 (b)).
Difference in the amount of heat recovered between the apparatus of the present invention and a commercially available product: (2.07-1.04) KW = 1.03KW
Thermal efficiency of the device of the present invention: 50KW / (50 + 2.63-1.03) KW = 97%

(About drainage receiving plate 5)
The drainage receiving plate 5 will be described with reference to FIG. 15 and the like.
The drainage receiving plate 5 is a member for receiving condensed water that condenses water vapor contained in combustion exhaust gas and condenses on the inner surface of the tubular member 10 of the heat exchange element 1b during latent heat recovery in the secondary heat exchanger 3. be.
The drainage receiving plate 5 is a metal plate-shaped member such as SUS, and is provided between the primary heat exchanger 2 and the secondary heat exchanger 3 (see FIGS. 1 to 2).
The drainage receiving plate 5 is provided with a drainage pipe 55 on the right side, and is provided in such a manner that the right side (drainage pipe side) is slightly inclined downward (preferably with an inclination angle of 0.2 ° or more).
According to such a drainage receiving plate 5, even if the condensed water drips down along the inner surface of the tubular member 10, it can be received by the entire drainage receiving plate 5 (see FIG. 15C), and a considerable amount of water can be received. Although it has a water storage capacity, it can be quickly discharged to the outside through a drain pipe 55.

The drainage receiving plate 5 is provided with an opening 5a at a portion corresponding to the installation position of the heat exchange elements 1a and 1b (see FIGS. 15 (b), (c) and 5 (b)). That is, an opening 5a having the same number, arrangement, and position as the number, arrangement, and position of the tubular members 10 forming the heat exchange elements 1a and 1b is provided.
By providing such an opening 5a, the combustion exhaust gas C from each heat exchange element 1a in the primary heat exchanger 2 to each heat exchange element 1b in the secondary heat exchanger 3 can be circulated without being blocked (). See FIG. 6).
That is, if the drainage receiving plate 5 does not have the opening 5a, the supply of the combustion exhaust gas C to the secondary heat exchanger 3 is obstructed, but by providing the opening 5a, such a problem does not occur. ..
The opening 5a preferably has the same shape (square) as the shape of the end openings of the heat exchange elements 1a and 1b, but may have a shape different from the shape of the end openings.

The opening 5a is the same as or slightly narrower than the end opening of the tubular member 10 forming the heat exchange elements 1a and 1b.
This is because when the opening 5a is made larger than the end opening of the heat exchange element 1b, when the condensed water condensed on the inner surface of the tubular member 10 of the heat exchange element 1b falls along the inner surface, the opening 5a is further opened. This is because it may pass through and fall into the combustor, which may adversely affect the combustion reaction.
Further, if the size of the opening 5a is made significantly smaller than the end opening of the heat exchange element 1b, the above problem may occur due to the obstruction of the flow path of the combustion exhaust gas C with respect to the secondary heat exchanger 3. be.
On the other hand, since the opening 5a in the heat exchange device 4 of the present invention is the same as or slightly narrower than the end openings of the heat exchange elements 1a and 1b, the heat exchange element 1b is prevented from occurring while preventing the above-mentioned problems from occurring. Condensed water condensed on the inner surface of the can be reliably received (see FIG. 15 (c)).

A wall-shaped weir portion 5b is provided around the opening 5a (see FIG. 15B).
As a result, the condensed water collected in the drainage receiving plate 5 is prevented from leaking downward from the opening 5a.
That is, if the weir portion 5b is not provided, the condensed water collected in the drainage receiving plate 5 may fall downward from the opening 5a, but by providing the weir portion 5b, such a problem may occur. While preventing this, the condensed water can be reliably drained (see FIGS. 15 (b) and 15 (c)).

According to such a drainage receiving plate 5, it is possible to drain water while reducing the condensed water accumulated in the drainage receiving plate 5 due to evaporation by convection heat or radiant heat in the apparatus.
That is, not only the condensed water can be drained, but also the amount of the drained water can be reduced at the same time.
Therefore, even if a large amount of condensed water is generated, it can be treated smoothly and promptly by a rational method.

(About tube expansion processing)
The tube expansion process in the tubular member 10 will be described with reference to FIG.
16A is a perspective view of a single-ended tube expansion type heat exchange element, FIG. 16B is an internal plan view of a heat exchanger provided with the heat exchange element of (a), and FIG. 16C is shown in FIG. Shows the side view of (b).
As shown in FIG. 16, the heat exchange element 1 is provided with a tube expansion portion 1z in which the width of a part of the tube in the tubular member 10 is expanded from the other part.
Specifically, a square ring made of the same metal (SUS) as the tubular member 10 is fitted to the lower end of the tube and closely joined by brazing (FIG. 16A), or the tube itself of the tubular member 10 itself. The width of the square at the lower end is increased by one size to expand the width of a part of the pipe.
By such tube expansion processing, the heat exchange element 1 can be toughened.
Specifically, when the heat exchange elements 1a and 1b receive the flow of the second heat exchange medium (water) from the outside, for example, they can have the pressure resistance and the impact resistance strength related to the flow.
As a result, it is not necessary to provide the base plates 27 and 37 on the tube expansion portion 1z side (lower end portion side) for each heat exchange element 1, and it is sufficient to provide the base plates 27 and 37 only on the upper end portion side (FIG. 16). (B), (c), see FIG. 3 and the like).
This is because the base plates 27 and 37 are members that make the tubular member 10 tough, and it is not necessary to make the tube expansion portion 1z side particularly tough by the tube expansion process.
Therefore, it is possible to reduce the number of parts (base plates 27 and 37), reduce the assembly / manufacturing man-hours and related costs associated with the reduction of the number of parts, and reduce the weight due to the reduction of the number of parts.

Further, by using the heat exchange element 1 that has been subjected to tube expansion processing, it is possible to realize a separation distance W between the heat exchange element 1 and the heat exchange element 1 that cannot be realized by press working or machining.
For example, when the tubular members 10 are arranged in a row, the lower end portions (square sides) of the tube expansion portion 1z are butted and arranged, and the butted portions are tightly joined by brazing or the like.
As shown in FIG. 17, in this case, the separation distance W between the adjacent tubular member 10 and the tubular member 10 is the width d1 of the original pipe from the width of the pipe (the width of the expanded portion d2) in the portion subjected to the tube expansion process. It is equal to the subtracted value (d2-d1).
Therefore, when the separation interval W is determined in advance, the tubular member 10 is expanded so that the tube expansion portion width d2 becomes W + d1, so that the adjacent heat exchange elements 1 are separated from each other by the separation interval W. Can be arranged.
For example, when it is desired to arrange tubular members 10 having a tube width (the length of one side of a square in a cross section) of 10 mm uniformly at a separation interval of 1 mm, the width of the lower end portion (tube expansion portion width d2) is 11 mm (=). A square ring having an outer width of 11 mm (inner width of 10 mm) may be tightly joined to the lower end portion so as to be 10 + 1), or the tubular member 10 itself may be processed so that the width of the lower end portion is 11 mm.
It is also possible to form a flow space that does not leak water, which is the second heat exchange medium C, by abutting and tight-junctioning the tube expansion portions 1z of the tubular member 10.

18A is a perspective view of a heat exchange element having a tube expansion type at both ends, FIG. 18B is an internal plan view of a heat exchanger provided with the heat exchange element of (a), and FIG. 18C is shown in FIG. Shows the side view of (b).
As shown in FIG. 18A, tube expansion portions 1z can be provided at both ends of the heat exchange element 1 (tubular member 10).
As a result, the heat exchange element 1 can be further toughened.
Further, it is not necessary to provide the base plates 27 and 37 not only on the lower end side of each heat exchange element 1 but also on the upper end side (see FIGS. 18 (b) and 18 (c)).
Therefore, it is possible to reduce the number of parts, the assembly / manufacturing man-hours and related costs associated with the reduction of the number of parts, and the weight reduction associated with the reduction of the number of parts, as compared with the single-ended tube expansion type.

19A is a perspective view of a heat exchange element having both ends and a central expansion tube, and FIG. 19B is an internal plan view of a heat exchanger provided with the heat exchange element of (a). c) shows the side view of (b).
As shown in FIG. 19A, in addition to the tube expansion portions 1z at both ends of the heat exchange element 1 (tubular member 10), the tube expansion portions 1z may be provided by brazing a square ring at the center portion.
As a result, the heat exchange element 1 can be made tougher than the tube-expanded type at both ends.
It should be noted that not only the central portion but also the portions other than both ends may be expanded if the construction is performed so as to have the same height.
Also in this case, it is not necessary to provide the base plates 27 and 37 on the lower end side and the upper end side of each heat exchange element 1 (see FIGS. 19 (b) and 19 (c)), and the number of parts is reduced as in the case of the double-ended type. In particular, according to the heat exchange element 1 having both ends and a central expansion tube, even if a high-pressure heat medium (second heat exchange medium) is subjected to the flow, the deflection can be minimized.

20 (a) shows a perspective view of a straight type heat exchange element, FIG. 20 (b) shows an internal plan view of a heat exchanger provided with the heat exchange element of (a), and FIG. 20 (c) shows an internal plan view of the heat exchanger. , (B) is shown.
As shown in FIG. 20 (a), a straight type heat exchange element 1 without the tube expansion portion 1z can also be adopted.
In this case, as shown in FIGS. 20 (b) and 20 (c), the heat exchange element 1 can be firmly fixed by joining the upper and lower base plates 27 and 37.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.
For example, in the above-described embodiment, as the heat exchange element 1, the one in which the collision plate 11 is provided inside the tubular member 10 is used, but the heat exchange element 1 in which the collision plate 11 is not provided inside the tubular member 10 is used. You can also do it.
Even in this case, the combustion exhaust gas flowing inside the tubular member 10 can be cooled by water via the tubular member 10, and in exchange for this, the exhaust heat (sensible heat and latent heat) of the combustion exhaust gas can be removed. Since it can be recovered by water, it functions as a heat exchanger and an integrated heat exchanger.
Further, instead of arranging the heat exchange elements 1 in a staggered pattern, both the front-back method and the left-right direction can be arranged in parallel or irregularly.
Further, in the above-described embodiment, the exhaust cover 6 (including the exhaust port 61) is attached to the uppermost portion in order to change the exhaust gas discharge direction from the vertical direction to the horizontal direction (see FIGS. 1, 2, etc.), but the exhaust gas is exhausted. By removing the cover 6, the exhaust gas discharge direction can be set to the vertical direction.
Further, the heat exchange device 4 of the present invention can also be used in addition to the water heater (heating of water).
For example, the heat exchange device 4 of the present invention can be used as a regenerator for concentrating the hygroscopic aqueous solution circulating in the absorption chiller, and in this case as well, the waste heat of the combustion exhaust gas can be effectively used for heat exchange. can.
In addition, in a reformer for producing hydrogen, which is the fuel of a fuel cell, by thermal decomposition from natural gas, etc., exhaust heat is recovered by heat exchange between combustion exhaust gas and air or water, and the recovered heat is used as a reserve for fuel. There is an example of a heat exchanger that reuses for heating and reuses the generated condensed water in a reformer.

1,101 Heat exchange element 1a Heat exchange element in the primary heat exchanger 1b Heat exchange element in the secondary heat exchanger 1z Tube expansion part 10,110 Tubular member 11,111 Collision plate 2 Primary heat exchanger 21 Heat exchange element group 25 Side Plate 26 Manifold 27 Base plate 27a Opening 3 Secondary heat exchanger 31 Heat exchange element group 35 Side plate 37 Base plate 37a Opening 36 Manifold 4 Heat exchanger 5 Drain receiving plate 5a Opening 5b Weir 55 Drain pipe 6 Exhaust cover 61 Exhaust port 71 Inlet header 72 Outlet header 73 U-shaped tube A Collision jet B Swirling flow C First heat exchange medium D Second heat exchange medium O Axis line W Separation interval

Claims (8)

In a heat exchanger composed of multiple heat exchangers
In the plurality of heat exchangers, heat exchange elements made of tubular members for circulating the first heat exchange medium inside and circulating the second heat exchange medium to the outside are vertically erected in the same arrangement. Includes a first heat exchanger and a second heat exchanger
A heat exchanger characterized in that the second heat exchanger is provided above the first heat exchanger. The heat exchange device according to claim 1, wherein each heat exchange element in the second heat exchanger is provided above each heat exchange element in the first heat exchanger. The first heat exchange medium can be circulated inside the heat exchange element in the first heat exchanger and then circulated inside the heat exchange element in the second heat exchanger. , The second heat exchange medium can be circulated outside the heat exchange element in the second heat exchanger and then circulated outside the heat exchange element in the first heat exchanger. The heat exchange device according to claim 1 or 2, further comprising a mechanism. The heat exchange according to any one of claims 1 to 3, wherein a combustor that generates combustion gas can be installed below the first heat exchanger as the first heat exchange medium. Device. A plate-shaped member is provided between the first heat exchanger and the second heat exchanger.
According to any one of claims 1 to 4, the plate-shaped member is provided with an opening in a portion corresponding to the installation position of each heat exchange element and a weir portion surrounding the opening in a wall shape. The heat exchanger described. The heat exchange device according to any one of claims 1 to 5, wherein each heat exchange element is provided with a tube expansion portion in which the width of a part of the tube in the tubular member is expanded from the other part. The heat exchange according to any one of claims 1 to 6, wherein each heat exchange element is provided with a collision plate inclined with respect to the axis of the tubular member inside the tubular member. Device. In the method of manufacturing a heat exchanger composed of a plurality of heat exchangers,
In the plurality of heat exchangers, heat exchange elements made of tubular members for circulating the first heat exchange medium inside and circulating the second heat exchange medium to the outside are vertically erected in the same arrangement. Includes a first heat exchanger and a second heat exchanger
A method for manufacturing a heat exchanger, which comprises a step of providing the second heat exchanger above the first heat exchanger.

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