JP2012049091A - Heater mounting structure and heat exchanger provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater mounting structure which is capable of obtaining high heating efficiency by increasing the amount of heat transferred from a heater to a part to be heated.SOLUTION: The heater mounting structure includes a heater H and a holder HL holding the heater H and mounted on a part 1 to be heated. The holder HL comprises a front plate part 30 and a rear plate part 20 facing each other across the heater H and is shaped like a case surrounding the heater H. The heater H is in surface contact with the holder HL so that heat can be transferred to the rear plate part 20. The rear plate part 20 is in face-to-face contact with the part 1 to be heated.

Description

  The present invention relates to a heater mounting structure used to prevent, for example, freezing of a heat exchanger constituting a hot water supply apparatus, and a heat exchanger provided with this structure.

  As means for attaching the antifreezing heater to the heat exchanger, there are structures described in Patent Documents 1 and 2. In the structures described in these documents, a cylindrical heater is held by a metal holder, and this holder is attached to the outer surface of the heat exchanger. The heater is in direct contact with the outer surface of the heat exchanger, and the holder is arranged to cover the front side of the heater. According to such a configuration, the heat of the heater can be directly transmitted to the heat exchanger. Further, the heater can be protected by the holder.

  However, the prior art has room for improvement as follows.

  That is, the heater is in direct contact with the outer surface of the heat exchanger, but if the heater is cylindrical, the heater is only in line contact with the outer surface of the heat exchanger. For this reason, there is little heat transfer amount from a heater to a heat exchanger. The outer surface of the heat exchanger often has distortion and other irregularities, but in such a case, the contact area between the heater and the heat exchanger is further reduced, and the amount of heat transfer to the heat exchanger is further increased. Less. As a result, conventionally, the heating efficiency has been somewhat low. In order to save power and reduce the size of the heater, it is desirable to increase the amount of heat transfer from the heater to the heat exchanger as much as possible to increase the heating efficiency. There was room for improvement.

Japanese Utility Model Publication No. 61-96261 Japanese Utility Model Publication No. 3-12239

  The present invention has been conceived under the circumstances described above, and has a heater mounting structure capable of obtaining a high heating efficiency by increasing the amount of heat transfer from the heater to the site to be heated, and An object of the present invention is to provide a heat exchanger having this structure.

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

  The heater mounting structure provided by the first aspect of the present invention is a heater mounting structure comprising: a heater; and a holder that holds the heater and is attached to a portion to be heated. The holder has a front plate portion and a back plate portion facing each other with the heater interposed therebetween, and has a case shape surrounding the heater. The heater faces the holder so that heat can be transferred to the back plate portion. They are in contact with each other, and the back plate portion is in a state of being in face-to-face contact with the portion to be heated.

According to such a configuration, even if the heater has a rod shape such as a columnar shape, or other shapes, and it is difficult to bring the heater into contact with the heating target portion over a wide area, the heater and the holder It is possible to increase the amount of heat transfer from the heater to the back plate of the holder. On the other hand, since the back plate part of the holder is in contact with the heating target part, the contact area between the back plate part and the heating target part can be increased. Therefore, according to the present invention, it is possible to increase the amount of heat transfer from the back plate portion of the holder that receives a lot of heat from the heater to the heating target part, and the heater is brought into contact with the heating target part over a wide area. The effect almost equivalent to is obtained. As a result, the heating efficiency is higher than before, which is advantageous in terms of power saving and heater miniaturization. In addition, the holder has a front plate portion in addition to the back plate portion, and has a case shape surrounding the heater, so that the heater can be protected, and the heat of the heater is largely released to the outside. Loss is reduced.

  In the present invention, it is preferable that the heater has a rod shape, and the holder has a side wall standing upright from the back plate portion and extending in a certain direction and in surface contact with the heater. The surface contact area is provided so as to extend over substantially the entire length of the heater in the longitudinal direction.

  According to such a configuration, for example, a large contact area between a rod-shaped heater such as a cylindrical shape and a holder can be appropriately realized by a simple configuration, and when a rod-shaped heater is used, the heating efficiency is increased. It is suitable for.

  In the present invention, preferably, a member having a spring property is used as means for attaching the holder to the portion to be heated, and the back plate portion of the holder is used for the heating subject by utilizing the spring property of the member. It is pressed against the part.

  According to such a configuration, it is possible to appropriately maintain the state in which the back plate portion of the holder is in contact with the heating target portion.

  In this invention, Preferably, the said holder is comprised combining the front side member which has the said front board part, and the rear side member which has the said back board part, and the said rear side member is rather than the said front side member. The material has high thermal conductivity.

  According to such a structure, the effect which reduces the heat dissipation from the front side member of a holder is acquired, and it becomes more preferable to raise the heating efficiency with respect to a heating object site | part.

  In this invention, Preferably, the said heater and the said front side member are comprised so that it may not contact.

  Such a configuration is more preferable for preventing heat transfer from the heater to the front member and reducing the amount of heat released from the front member.

  The heat exchanger provided by the 2nd side surface of this invention is a heat exchanger which has a heat exchanger tube, Comprising: As the attachment structure of the heater for aiming at the freeze prevention of the said heat exchanger tube, 1st side surface of this invention The heater mounting structure provided by is used.

  According to such a configuration, the same effect as described for the heater mounting structure provided by the first aspect of the present invention can be obtained, and the heating efficiency for the heat exchanger can be increased to save power. However, accurate freezing prevention can be achieved.

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

It is a principal part perspective view which shows an example of the heat exchanger provided with the attachment structure of the heater which concerns on this invention. FIG. 2 is a perspective view showing a holder used in the heater mounting structure shown in FIG. FIG. 3 is an exploded perspective view of the holder shown in FIG. It is IV-IV sectional drawing of FIG.

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

  In the embodiment shown in FIG. 1, a freezing prevention heater H is attached to the side surface of the can 1 of the heat exchanger HE using a holder HL. The heat exchanger HE is a component device of a hot water supply apparatus, for example, and has a configuration in which a heat transfer tube 5 having a large number of fins 50 is arranged in a metal can 1 having an upper surface and a lower surface opened. . In this heat exchanger HE, combustion gas is supplied into the can 1 from the lower surface opening. Heat is recovered from the combustion gas by the heat transfer tube 5, and hot water flowing through the heat transfer tube 5 is heated. The combustion gas after heat recovery is discharged from the upper surface opening of the can 1.

  The heater H is a cylindrical electric heater. In the present embodiment, as shown in FIG. 3, two heaters H to which a wiring cord 90 is connected are used. The holder HL has a case shape in which the heater H can be housed, and includes a rear member 2 having a back plate portion 20, a front member 3 having a front plate portion 30, and a mounting piece 4. Is also made of metal.

  The rear member 2 of the holder HL is a member that directly holds the heater H. As means for holding the heater H, the back plate portion 20 is provided with a pair of side walls 21 erected from both side edges and a plurality of erected portions 22. Each upright portion 22 is formed using, for example, a cutting and raising method. A region A1 between the side wall 21 and the upright portion 22 is a heater arrangement region. The upright portion 22 can be bent and deformed with an elastic restoring force, and the upright portion 22 is bent and deformed to increase the distance from the side wall 21 so that the heater H can easily enter and hold between them. Is possible. A protruding portion 23 is provided at an upper portion of the side wall 21 that faces the upright portion 22, which ensures the holding of the heater H and prevents the heater H from being accidentally detached. Fulfill. Moreover, it is useful also for mounting | wearing of the front side member 3 so that it may mention later.

  The side wall 21 and the upright portion 22 have a curved shape corresponding to the outer surface of the heater H, and are formed so as to be in surface contact with the outer surface of the heater H together. In particular, the surface contact area between the side wall 21 and the heater H is provided so as to extend over substantially the entire length area in the longitudinal direction of the heater H. For this reason, when the heater H generates heat, the heat of the heater H is efficiently transmitted to the back plate portion 20 of the rear member 2. The rear member 2 is made of a material having high thermal conductivity. As an example, the surface of a general steel material is subjected to aluminum plating.

  The front member 3 is a member that covers the front side (upper surface side in FIG. 3) of the heater H, and has a front plate portion 30 and a pair of side wall portions 31 connected to both side edges of the front plate portion 30. The front member 3 is detachably attached to the rear member 2. As a means for this purpose, the front member 3 is provided with a plurality of engagement holes 33 corresponding to the plurality of protrusions 23 of the rear member 2, and by engaging them, the front member 3 is moved to the rear side. It can be prevented from separating from the member 2. Further, in a state where the front member 3 is assembled to the rear member 2, the front plate portion 30 is configured to be separated from the heater H and not directly contact the heater H. As a result, heat transfer from the heater H to the front plate portion 30 is prevented. The front member 3 is a material having a lower thermal conductivity than the rear member 2. One example is stainless steel.

  The attachment piece 4 is for attaching the holder HL to the can 1 of the heat exchanger HE, and is configured, for example, by bending a belt-like metal piece. Similarly to the front member 3, the mounting piece 4 is preferably made of a material having a lower thermal conductivity and at least a lower thermal conductivity than the rear member 2. The attachment piece 4 is joined to the front member 3 by, for example, a spot weld W, and extends above and below the front member 3 (see also FIG. 2). An engaging protrusion 40 is provided on the upper end portion of the mounting piece 4. In addition, the lower end portion is provided with a contact portion 41 for making contact with an upright wall 12a of a heat exchanger HE described later, and a positioning projection 42. The attachment piece 4 has a spring property and can be bent and deformed with an elastic restoring force in the thickness direction of the holder HL.

  As shown in FIG. 4, the holder HL is attached to the can body 1 so that the back plate portion 20 is in contact with the side surface of the can body 1. More specifically, the can body 1 is provided with an upper flange 10a and a lower flange 10b. As a means for reinforcing these portions and their peripheral portions, auxiliary members 11 to 13 are welded to the can body 1. Or brazed. The reinforcing member 11 is provided with a portion for forming a gap 19 between the side surface of the can 1 and an engaging hole portion 11a is provided in this portion. The upper end of the attachment piece 4 is inserted into the gap 19, and the engagement protrusion 40 engages with the engagement hole 11 a. The reinforcing member 12 has an upright standing wall 12a, but the abutting portion 41 of the mounting piece 4 is located inside the upstanding wall 12a (near the can body 1) and abuts on the upstanding wall 12a. . The reinforcing member 13 has an upright wall 13a positioned further inside than the upright wall 12a, and the positioning projection 42 of the mounting piece 4 is inserted into the hole 13b provided in the upright wall 13a. With such a structure, the mounting piece 4 is supported and positioned by the reinforcing members 11 to 13.

  In the natural state, the attachment piece 4 has a form as indicated by an imaginary line in FIG. 4. However, in the attachment state indicated by the solid line in FIG. 4, the upper part and the lower part are bent and deformed. Therefore, in the state where the attachment piece 4 is attached to the can 1, spring forces as indicated by reference signs F <b> 1 and F <b> 2 are generated. By the action of this spring force, the attachment of the attachment piece 4 to the can body 1 is ensured, and the attachment piece 4 can be prevented from being inadvertently detached from the can body 1. In addition, the spring force acts as a force for pressing the holder HL against the can 1. Accordingly, it is possible to ensure and stabilize the state in which the back plate portion 20 of the holder HL and the side surface of the can body 1 are in contact with each other.

  Next, the operation of the heater mounting structure will be described.

  First, when the heater H is heated to prevent freezing of the heat exchanger HE, the heat of the heater H is transmitted to the pair of side walls 21 and the upright portions 22 of the holder HL, and is also transmitted to the back plate portion 20. As described above, since the pair of side walls 21 and the standing part 22 are in contact with the heater H over a wide area, most of the heat of the heater H is efficiently transmitted to the back plate part 20. Since the thermal conductivity of the rear member 2 is high, it is preferable to increase the amount of heat transmitted to the back plate portion 20.

  On the other hand, the action of transferring the heat of the heater H to the can body 1 of the heat exchanger HE is performed at the contact portion between the back plate portion 20 of the holder HL and the can body 1. Here, the back plate portion 20 has a flat plate shape, and the contact area between the back plate portion 20 and the can 1 can be increased. Although the surface of the can body 1 may be distorted or have minute irregularities, the contact area between the back plate 20 and the can body 1 can be relatively large even in such a case. Is possible. Therefore, heat transfer from the back plate portion 20 to the can 1 can be performed efficiently. Based on such a series of actions, in the present embodiment, the heat of the heater H is efficiently transmitted to the can 1 of the heat exchanger HE, and the heating efficiency can be increased.

  The holder HL has a case shape surrounding the heater H, and an effect of making it difficult for the heat of the heater H to escape to the outside is obtained. Since the front plate portion 30 of the holder HL is not in contact with the heater H, the loss of heat of the heater H radiated through the front plate portion 30 is also suppressed. Further, since the front member 3 is made of a material having a low heat transfer rate, it is also appropriately prevented that most of the heat of the heater H is transferred from the rear member 2 to the front member 3 and radiated. If wasteful heat dissipation from the holder HL is prevented in this way, the back plate portion 20 becomes high by that amount, and the amount of heat transfer from the back plate portion 20 to the can 1 of the heat exchanger HE increases. The heating efficiency can be further increased. If the heating efficiency is increased, it is possible to favorably save power and reduce the size of the heater H.

  The present invention is not limited to the contents of the above-described embodiment. Various modifications can be made to the heater mounting structure and the specific configuration of each part of the heat exchanger according to the present invention.

  The heater is not limited to a columnar shape or other rod shape. Even if the heater has a shape other than a rod shape, it may be difficult to directly contact the heater with a large area in a large area, and in such a case, the present invention can be applied to solve the problem. it can.

  The holder referred to in the present invention has a case shape surrounding the heater, but it is not necessary to surround the heater so as to seal it. In short, the holder has a front plate portion and a back plate portion that are opposed to each other with the heater interposed therebetween and may be in a case shape surrounding the heater, and the specific shape, size, material, and the like may be variously changed. Can do. Moreover, the holder should just be arrange | positioned so that a backplate part may contact a heating object site | part, and the attachment means of this holder itself is not limited. For example, a means of screwing the holder to the heating target part or a member in the vicinity thereof may be employed.

  The site to be heated as referred to in the present invention is not limited to the heat exchanger or its can, and various sites can be used as the site to be heated. The heater mounting structure according to the present invention can also be used for purposes other than anti-freezing. The heat exchanger according to the present invention is not limited to that for a hot water supply apparatus.

HE Heat exchanger H Heater HL Holder 1 Can body (part to be heated)
2 Rear member 3 Front member 4 Mounting piece 20 Back plate portion 30 Front plate portion

Claims (6)

A heater,
A holder that holds the heater and is attached to a portion to be heated;
A heater mounting structure comprising:
The holder has a front plate portion and a back plate portion facing each other with the heater interposed therebetween, and has a case shape surrounding the heater,
The heater is in surface contact with the holder to enable heat transfer to the back plate portion,
The heater mounting structure, wherein the back plate portion is in a state of facing the heating target portion. The heater is rod-shaped,
The holder has a side wall that stands up from the back plate and extends in a certain direction and is in surface contact with the heater;
2. The heater mounting structure according to claim 1, wherein the surface contact region between the side wall and the heater is provided so as to extend over substantially the entire length region in the longitudinal direction of the heater.   As a means for attaching the holder to the heating target part, a member having a spring property is used, and the back plate portion of the holder is pressed against the heating target part using the spring property of the member. The heater mounting structure according to claim 1 or 2. The holder is configured by combining a front member having the front plate portion and a rear member having the back plate portion,
The heater mounting structure according to any one of claims 1 to 3, wherein the rear member is made of a material having a higher thermal conductivity than the front member.   The heater mounting structure according to claim 4, wherein the heater and the front member are configured not to contact each other. A heat exchanger having a heat transfer tube,
A heat exchanger, wherein the heater mounting structure according to any one of claims 1 to 5 is used as a heater mounting structure for preventing the heat transfer tube from freezing.

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