JP2002257482A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger capable of bonding a heat transfer fin closely with heat transfer tubes comparatively simply and surely even though the expanding work of the heat transfer tube is impossible or brazing or the like is impossible for the reason of the material of the same. SOLUTION: In the heat exchanger wherein the heat transfer tubes 40, 41 for passing heat transfer fluid are provided so as to penetrate through a plurality of heat transfer fins 43, 48 in the lengthwise direction of the same, the heat transfer fins 43, 48 are provided with through holes 45, 46, 51, 52 for penetrating the heat transfer tubes 40, 41 while a notch 54, capable of expanding the opening of the same in for the penetration of the heat transfer tubes 40, 41 through the through holes 45, 46, 51, 52, is provided around the peripheral rims of the through holes 45, 46, 51, 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger in which a heat transfer tube through which a heat transfer fluid passes is provided so as to penetrate a plurality of heat transfer fins in the longitudinal direction.

[0002]

2. Description of the Related Art In such a heat exchanger, when the heat transfer tube and the heat transfer fin are formed separately, in order to efficiently transfer the heat of the heat transfer fin to the heat transfer tube, the two must be securely connected. It is necessary to adhere. Therefore, conventionally, a heat transfer tube is inserted into a through hole provided in a heat transfer fin, and then the heat transfer tube is expanded so that an outer peripheral portion of the heat transfer tube is brought into close contact with a periphery of the through hole. (For example, see JP-A-2000-146)
Further, there is known a configuration in which a heat transfer fin and a heat transfer tube are bonded by brazing or the like after pipe expansion processing.

[0003]

However, in a configuration in which the pipes are brought into close contact with each other by, for example, pipe expansion of a heat transfer pipe,
It may be difficult depending on the material of the heat transfer tube, and even if the material is possible, it becomes difficult when the thickness of the heat transfer tube is large, and it is not always satisfactory. Also, brazing may not be possible depending on the material of the heat transfer tubes and heat transfer fins, and can be performed only on heat transfer tubes and heat transfer fins of limited materials. There was room.

[0004] The present invention focuses on such conventional problems, and its object is to make it impossible to expand the heat transfer tube even if it is impossible to braze the material. Even if it is, the heat transfer fin and the heat transfer tube can be relatively easily
Another object of the present invention is to provide a heat exchanger that can be surely brought into close contact.

[0005]

According to the first aspect of the present invention, a heat transfer tube through which a heat transfer fluid passes passes through a plurality of heat transfer fins in a longitudinal direction thereof. Wherein the heat transfer fins are provided with through holes for inserting the heat transfer tubes, and are enlarged with the insertion of the heat transfer tubes into the through holes. An openable notch is provided on the periphery of the through hole.

That is, the heat transfer fin has a through hole through which the heat transfer tube is inserted, and a notch portion which can be enlarged and opened along with the insertion of the heat transfer tube into the through hole is provided on a peripheral edge of the through hole. Therefore, by making the through hole a suitable amount smaller than the size of the outer peripheral portion of the heat transfer tube, and inserting the heat transfer tube into the through hole, the cutout portion at the peripheral edge of the through hole is enlarged and the heat transfer tube is opened. And at the same time, the peripheral edge of the through hole is securely adhered to the outer peripheral portion of the heat transfer tube. Therefore, even if it is impossible to expand the heat transfer tube or if brazing is impossible due to the material, the heat transfer fins and the heat transfer tube can be relatively easily and securely adhered to each other. As a result, desired heat conduction can be expected.

It should be noted that it is also possible to insert a heat transfer tube into a through-hole having no notch without providing the above-described notch at the periphery of the through-hole. However, in this case, for example, if the outer peripheral portion of the heat transfer tube and the through hole are substantially the same size, close contact between the two cannot be expected, and the through hole is smaller than the outer peripheral portion of the heat transfer tube. Then, a large force is required to insert the heat transfer tube, that is, not only a large press-fitting device is required, but also deformation and damage of the heat transfer fin, and further, seizure occurs between the heat transfer fin and the heat transfer tube. There is a possibility that it is practically impossible.

On the other hand, according to the first aspect of the present invention, a large-sized press-fitting device or the like is not required by the enlarged opening action of the notch provided in the peripheral edge of the through hole, and
The heat transfer fin and the heat transfer tube can be securely brought into close contact with each other without deformation or damage of the heat transfer fin.

According to the second aspect of the present invention, the through hole is formed inside a cylindrical portion bent in a direction in which the heat transfer tube is inserted from the heat transfer fin, and the notch portion is The heat transfer fin is formed in a continuous groove shape from a portion adjacent to the cylindrical portion to a tip of the cylindrical portion.

That is, the through-hole is formed inside the cylindrical portion bent in the direction in which the heat transfer tube is inserted from the heat transfer fin, and the notch portion which can be enlarged and opened is formed from a position adjacent to the cylindrical portion. Since it is formed in a continuous groove shape to the tip of the cylindrical portion, it is possible to insert the heat transfer tube into the through hole as desired despite the presence of the cylindrical portion around the through hole. In the inserted state, the cylindrical portion around the through-hole surely adheres to the outer peripheral portion of the heat transfer tube, and the contact area between the heat transfer fin and the heat transfer tube increases, so that more efficient heat transfer is achieved. Conduction becomes possible.

According to the third aspect of the present invention, at least the outer peripheral portion of the heat transfer tube is made of a corrosion resistant material that is relatively resistant to corrosion.

That is, when a heat exchanger of this type is heated by a combustion exhaust gas such as a burner to exchange heat with a heat transfer fluid passing through a heat transfer tube, the temperature of the combustion exhaust gas increases with the heat exchange. As a result, condensed water called drain is generated. Although the condensed water has corrosiveness, the corrosion due to the condensed water can be suppressed by configuring at least the outer peripheral portion of the heat transfer tube with a corrosion-resistant material.

According to the fourth aspect of the present invention, a heat transfer cover is externally fitted to an outer peripheral portion of the heat transfer tube, and the heat transfer cover is made of the corrosion-resistant material. The heat transfer tube fitted outside is fitted inside the through hole of the heat transfer fin.

That is, since the heat transfer cover made of a corrosion-resistant material is fitted around the outer periphery of the heat transfer tube, the heat transfer cover can suppress corrosion of the heat transfer tube due to condensed water. When the heat transfer cover is corroded, only the heat transfer cover can be replaced. And even if the surface of the heat transfer cover is corroded, it takes a long time for the corrosion to reach the heat transfer tube, so that the corrosion resistance of the heat transfer cover can be effectively used, and it can be used for many months. Become.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a heat exchanger according to the present invention will be described with reference to the drawings. This heat exchanger is used, for example, for heating hot water in a hot water supply device, and the hot water supply device is, as shown in FIG.
A hot water supply heat exchanger 4 for heating the water supplied through the burner 2 by combustion of the burner 2 and supplying hot water to the hot water supply path 3;
The heating medium supplied through the heater 2 is heated by the combustion of the burner 2 and is provided with a heating heat exchanger 7 and the like flowing out to the high-temperature heating outgoing passage 6.

The water supply passage 1 is provided with a water filter 8, a water supply thermistor 9 for detecting a water supply temperature, and a water amount sensor 10 for detecting a water supply amount in order from the upstream side, and at a downstream side of the water amount sensor 10. Is connected to a bypass 11 for supplying water from the water supply channel 1 to the hot water supply channel 3 while bypassing the hot water supply heat exchanger 4. The hot water supply path 3 includes, in order from the upstream side, a hot water supply thermistor 12 for detecting the temperature of the hot water from the hot water supply heat exchanger 4, and a mixture of the hot water from the hot water supply heat exchanger 4 and the water from the bypass path 11. A mixing valve 13 for adjusting the ratio, a mixing thermistor 14 for detecting the temperature of the hot and cold water after being mixed by the mixing valve 13,
A water proportional valve 15 for adjusting the amount of hot water supplied through the hot water supply channel 3, an interrupt water amount sensor 16 for detecting an interrupt of general hot water supply, and an overpressure prevention device 17 are provided to heat the water supplied through the hot water supply channel 1. It is configured to supply hot water and to supply general hot water and bath water.

In the heating return path 5, in order from the upstream side,
A heating return thermistor 18, a makeup water tank 19, and a heating pump 20 are provided, and a heating outgoing high temperature thermistor 21 is provided near the heating heat exchanger 7 in the high temperature heating outgoing passage 6. For example, a high-temperature heating terminal D1 such as an indoor heating device is connected to the high-temperature heating terminal 6 and a high-temperature heating terminal D1 is connected to the high-temperature heating terminal D1.
Heating bypass 2 supplying bypass 1 to heating return 5
2 is also provided. On the downstream side of the heating pump 20 in the heating return path 5, a low-temperature heating outgoing path 23 is connected to provide a heating outgoing low-temperature thermistor 24. The low-temperature heating outgoing path 23 includes, for example, a floor heating device. Such a low-temperature heating terminal D2 is connected.

The make-up water tank 19 is connected to a make-up water passage 25 branched from a location between the water filter 8 and the water supply thermistor 9 in the water supply passage 1, and is connected to an overflow passage 26. Is provided with a makeup water valve 27 and a makeup water solenoid valve 28. The makeup water tank 19 is provided with an upper limit sensor 29 for detecting the upper limit of the water level and a lower limit sensor 30 for detecting the lower limit.
By controlling the opening and closing of the make-up water solenoid valve 28, the make-up water tank 1
9 is configured to be maintained between the upper limit sensor 29 and the lower limit sensor 30.

When the heating pump 20 is operated, the hot and cold water in the makeup water tank 19 flows through the heating return path 5, and a part of the hot water flows around the heating heat exchanger 7 and passes through the low-temperature heating outflow path 23. Is supplied to the heating type heat terminal D2, the remainder flows into the heating heat exchanger 7, and the hot water heated by the heating heat exchanger 7 is supplied to the high-temperature type heating terminal D1 through the high-temperature heating outgoing path 6, Both the hot water returned from the high-temperature heating terminal D1 and the hot water returned from the low-temperature heating terminal D2 are returned to the makeup water tank 19 through the heating return path 5.

The burner 2 is a multi-stage gas burner.
Is configured to produce a flame downward, and therefore
As shown in FIG. 2, the hot water supply heat exchanger 4 and the heating heat exchanger 7 heated by the burner 2 are arranged downstream of the burner 2 in the flow direction of the combustion exhaust gas, that is, below the burner 2. Has been established. The burner 2 is connected to a gas supply passage 31 for supplying general household fuel gas, which is branched into three systems, and each of the branch supply passages is provided with a gas switching solenoid valve 32 and is provided with a gas switching electromagnetic valve 32. The upstream gas supply path 31 is provided with a source gas solenoid valve 33 for interrupting the supply of fuel gas and an electromagnetic gas proportional valve 34 for adjusting the fuel gas supply amount. Further, combustion air is supplied to the burner 2. A supply fan 35 is provided, and an igniter 36 for igniting the burner 2 and a frame rod 37 for detecting ignition of the burner 2 are also provided.

As shown in detail in FIGS. 2 to 4, the hot water supply heat exchanger 4 includes a hot water supply sensible heat exchange section 4a for recovering the sensible heat of the combustion exhaust gas from the burner 2, and a sensible heat heat supply section for the hot water supply. The hot water supply latent heat exchange unit 4b is disposed downstream of the exchange unit 4a in the flow direction of the combustion exhaust gas of the burner 2, and recovers latent heat of the combustion exhaust gas of the burner 2. The same applies to the heating heat exchanger 7, and the heating sensible heat exchange section 7a for recovering the sensible heat of the combustion exhaust gas of the burner 2, and the flow direction of the combustion exhaust gas of the burner 2 more than the heating sensible heat exchange section 7a. And a latent heat exchange unit for heating 7b for recovering the latent heat of the combustion exhaust gas from the burner 2.

The hot water supply sensible heat exchange section 4a and the heating sensible heat exchange section 7a are integrally formed so as to conduct heat to each other, and the hot water supply latent heat exchange section 4b and the heating latent heat exchange section 4b are integrally formed. The heat exchanger 7b is formed integrally with the heat exchangers 4 and 7 so as to conduct heat to each other, so that the heat exchangers 4 and 7 can be made more compact. Also in 7, in addition to the sensible heat of the flue gas, the latent heat of the flue gas is recovered, and the value obtained by dividing the performance (heating capacity) of the device by the amount of energy input to the device, that is, the efficiency is effectively improved. Therefore, it is configured to realize high efficiency. The heat exchange units 4b and 7 are located below the hot water supply latent heat exchange unit 4b and the heating latent heat exchange unit 7b.
A drain recovery path 38 for recovering the drain, which is condensed water falling from b, and a drain neutralizing device 39 are provided to neutralize and discharge the collected drain.

The sensible heat exchanger 4 for hot water supply and heating
In a and 7a, a copper hot water supply heat transfer tube 40 for passing water from the water supply passage 1 as a heat transfer fluid and a copper heat transfer tube for passing a heat medium from the high-temperature heating terminal D1 as a heat transfer fluid. Heating heat transfer tubes 41 are provided so as to penetrate through a number of sensible heat transfer fins 43 arranged in the longitudinal direction thereof and housed in a sensible heat exchange casing 42. The heating heat transfer tube 41 and the heating heat transfer tube 41 are connected to each other by a copper U-shaped tube 44 outside the sensible heat exchange casing 42. As shown in FIG. 5A, the hot water supply heat transfer tube 40 includes a portion that is in contact with the heating heat transfer tube 41 so as to be able to conduct heat with the heating heat transfer tube 41, and a hot water supply transfer tube. The fin 43 for sensible heat transfer has an integrated through hole 45 for inserting the heat transfer tubes 40 and 41 and only the heat transfer tube 40 for hot water supply. Single type through hole 4
6 are provided in plurality.

The latent heat exchange section 4 for hot water supply and heating
Also in b and 7b, a copper hot water supply heat transfer tube 40 for passing water from the water supply passage 1 and a copper heating heat transfer tube 41 for passing a heat medium from the high-temperature type heating terminal D1 are arranged in the longitudinal direction. A plurality of latent heat transfer fins 48 disposed and housed in a latent heat exchange casing 47 are provided so as to penetrate therethrough, and each hot water supply heat transfer tube 40 and heating heat transfer tube 41 are provided.
Are connected to the outside of the latent heat exchange casing 47 by the same U-shaped tubes 44 as described above. As in the sensible heat exchange sections 4a and 7a described above, the hot water supply heat transfer tube 40 includes, as shown in FIG. 5B, a portion in contact with the heating heat transfer tube 41, and a hot water supply heat transfer tube. 40, but the latent heat exchange sections 4b, 7b
In, the outer peripheral portions of the heat transfer pipe for hot water supply 40 and the heat transfer pipe for heating 41 are covered with heat transfer covers 49 and 50.

That is, as shown in FIGS. 6A and 6B, in a portion where the hot water supply heat transfer tube 40 and the heating heat transfer tube 41 are in contact with each other, one outer peripheral portion of both heat transfer tubes 40, 41 is provided. The body heat transfer cover 49 is externally fitted, and a single heat transfer cover 50 is externally fitted in a portion consisting of only the hot water supply heat transfer tube 40, and the two heat transfer covers 49, 50 are connected to the latent heat exchange casing 47. It is configured to be located within. Both the heat transfer covers 49 and 50 are thicker than the heat transfer tube 40 and the heat transfer tube 41, and the heat transfer tube 40.
It is made of a corrosion-resistant material such as aluminum, stainless steel, titanium, or the like, which is more resistant to corrosion than copper constituting the heat transfer tube 41 for heating. The latent heat transfer fin 48 has an integrated through-hole 51 into which the hot water supply heat transfer tube 40 and the heating heat transfer tube 41 each having the integrated heat transfer cover 49 externally fitted therein, and a single heat transfer tube 51. A plurality of single-type through-holes 52 for internally fitting the hot water supply heat transfer tubes 40 with the cover 50 externally fitted thereto are provided.

The fin 43 for sensible heat transfer and the fin 48 for latent heat transfer are also made of a corrosion-resistant material such as aluminum, stainless steel, or titanium.
The integral through-hole 45 and the single-type through-hole 46 provided on the fins 48 and the integral-type through-hole 51 and the single-type through-hole 52 provided on the latent heat transfer fin 48 are all constituted by burring holes formed by burring. ing. That is, each through hole 4
The heat transfer fins 43, 46, 51, and 52 have heat opening fins 43, as shown in FIG.
48 is provided with a burring edge 53 as a cylindrical portion which is bent and protrudes on one side surface, and through holes 45, 46, 51, 52 are formed inside the burring edge 53, and each through hole 45, 46 is formed. , 51, 52 are inserted through the heat transfer cover 4
It is configured to be smaller by an appropriate amount than the outer peripheral portions of the heat transfer tubes 9 and 50 and the heat transfer tubes 40 and 41.

The respective through holes 45, 46, 51, 52
Of the fin 43 for sensible heat transfer and the single through-hole 46, more specifically, a portion of the fin 43 for sensible heat transfer adjacent to each burring edge 53. In the integrated through hole 51 and the singular type through hole 52 of the fin 48 for latent heat transfer, the fin 4 for the latent heat transfer.
8, a plurality of groove-shaped notches 54 are provided in a continuous state from the portion adjacent to each burring edge 53 to the tip of the burring edge 53.

Therefore, when the hot water supply heat transfer tube 40 and the heating heat transfer tube 41 are inserted through the integral type through hole 45 and the single type through hole 46 of the sensible heat transfer fin 43, When the hot water supply heat transfer tube 40 or the heating heat transfer tube 41, in which the integrated heat transfer cover 49 or the single heat transfer cover 50 is externally fitted, is inserted into the integrated through hole 51 or the single through hole 52,
With the insertion of the heat transfer covers 49 and 50 and the heat transfer tubes 40 and 41, the notches 54 are enlarged and opened, and the burring edge 53 is pulled in the insertion direction as shown in FIG. After the insertion is completed, the diameter is increased.
As shown in FIG. 7, the burring edge 53 is reduced in diameter to return to the original state, and the heat transfer covers 49 and 50 and the heat transfer tubes 40 and 41 are reduced.
Will surely be in close contact with the outer peripheral portion.

[Another Embodiment] (1) In the above embodiment, the heat transfer fins 43, 48 have through holes 45, 46, 5 having cylindrical burring edges 53.
1 and 52 are provided, and a groove-shaped notch portion 54 is provided in a state of being continuous from a portion adjacent to the burring edge 53 to a tip of the burring edge 53, but each through hole is formed without the burring edge 53. It is also possible to use a simple through-hole and to provide a notch on the periphery of the through-hole. In any case, the shape of the cutout portion is not limited to the groove-like shape as in the above-described embodiment, and is configured by, for example, a slit formed by a simple cut or a cutout having a certain width. The size and number of the notches provided in the through-holes, and the arrangement thereof, also take into account the material and thickness of the heat transfer fins 43 and 48, or the opening area and shape of the through-holes. Then, it is appropriately selected and executed.

(2) In the above embodiment, the latent heat exchange section 4
In b and 7b, an example is shown in which heat transfer covers 49 and 50 made of a corrosion-resistant material are externally fitted to the outer peripheral portions of the copper heat transfer tubes 40 and 41. For example, the heat pipe may have a double pipe structure, and the inner pipe may be made of a copper pipe and the outer pipe may be made of a corrosion-resistant material.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a water heater.

FIG. 2 is a perspective view showing a burner and a heat exchanger.

FIG. 3 is a side view of a sensible heat exchange unit.

FIG. 4 is a side view of the latent heat exchange unit.

FIG. 5 is a front view of a fin for sensible heat transfer and a fin for latent heat transfer.

FIG. 6 is a sectional view showing an assembled state of the latent heat exchange unit.

FIG. 7 is an enlarged perspective view of a main part of the heat transfer fin.

FIG. 8 is an enlarged sectional view of a main part when assembling the heat exchange unit.

[Explanation of symbols]

 40, 41 Heat transfer tubes 43, 48 Heat transfer fins 45, 46, 51, 52 Through holes 49, 50 Heat transfer cover 53 Tube portion 54 Notch portion

Claims (4)

[The claims] 1. A heat exchanger in which a heat transfer tube through which a heat transfer fluid passes is provided so as to penetrate a plurality of heat transfer fins in a longitudinal direction thereof, wherein the heat transfer fin comprises: A heat exchanger including a through-hole through which a heat transfer tube is inserted, and a notch portion that can be enlarged and opened as the heat transfer tube is inserted into the through-hole, and is provided at a peripheral edge of the through-hole. 2. The heat transfer fin according to claim 2, wherein the through hole is formed inside a tube portion bent from the heat transfer fin in a direction in which the heat transfer tube is inserted, and the cutout portion is formed in the heat transfer fin. 2. The heat exchanger according to claim 1, wherein the heat exchanger is formed in a continuous groove shape from a portion adjacent to the front end to the tip of the cylindrical portion. 3. The heat exchanger according to claim 1, wherein at least the outer peripheral portion of the heat transfer tube is made of a corrosion-resistant material that is relatively resistant to corrosion. 4. A heat transfer cover is externally fitted to an outer peripheral portion of the heat transfer tube, and the heat transfer cover is made of the corrosion-resistant material, and the heat transfer tube to which the heat transfer cover is fitted is: The heat exchanger according to claim 3, wherein the heat exchanger is internally fitted in a through hole of the heat transfer fin.