JPH10281683A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To release stress caused by the difference of coefficient of thermal expansion between a piping and a heat exchanger main body, and to prevent a thermal conductivity to a heating medium from being lowered by providing a pipe fixing groove for holding the piping and a groove communicating with the groove for housing the bent part of the piping and providing a clearance between the groove and the piping at the bent part. SOLUTION: A refrigerant piping 53 is turned several times by a bending molding and fixed to a division member 48a. A groove (clearance forming groove) 53b for forming a clearance between the refrigerant piping 53 and the division member 48a is formed on the outer surface of the division member 48a in the bent part of the refrigerant piping 53. The clearance forming groove 53b is formed in a substantially semicircular shape in a plan view and communicates with the pipe fixing groove. A step part is provided in a part in which the fixing groove is connected to the clearance forming groove. The bottom part of the clearance forming groove is lower than that of the fixing groove 53a. Further, a space with distance b is formed between the refrigerant piping 53 and the side wall of the clearance forming groove and a space with distance (c) is formed between the refrigerant piping 53 and the bottom part of the clearance forming groove 53b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger, and more particularly, to a heat exchanger that prevents a decrease in heat conductivity to a heat medium flowing through piping.

[0002]

2. Description of the Related Art FIGS. 5A and 5B are block diagrams showing an outdoor unit of a conventional refrigerant heating type air conditioner provided with a refrigerant heater. In the drawing, reference numeral 1 denotes a rectangular box-shaped housing, in which a partition plate 2 is provided.

The partition plate 2 is formed at a predetermined height from the inner bottom of the housing 1 to a substantially middle portion in the vertical direction of the housing, and partitions the inside of the housing into right and left. The upper end of the partition plate 2 is
An upper base plate 3 provided in parallel with the upper surface at a predetermined interval and provided from the upper end of the partition plate to the left side surface of the housing.
Is connected to the side end portion.

A space surrounded by the casing 1, the partition plate 2 and the upper base plate 3 is called a heat exchange chamber 4, and an outdoor heat exchanger (not shown) and an outdoor fan 5 face each other. Placed.

[0005] The space adjacent to the heat exchange chamber 4 is called a machine room 6, in which a compressor 7, a suction cup 8 and connection pipes 9 are accommodated. A plurality of packed valves 10 for connecting to a refrigerant pipe extending from an indoor unit (not shown) protrude from the right side surface of the housing 1 which is the machine room 6 side.

In addition, at the upper part of the machine room 6,
A control board 11 and a connector 12 are attached, and are electrically connected to electric components arranged in the outdoor unit. A refrigerant heating unit 13 is disposed on the back of the control board 11 and over the machine room 6 and the heat exchange room 4.

[0007] In the refrigerant heating unit 13, a combustor 14 is disposed substantially at the center in the left-right direction, and a refrigerant heater 15 is connected to the left side of the combustor. That is, the combustor 14 and the refrigerant heater 15 are mounted on the upper base plate 3. A combustion blower 16 is connected to the right side of the combustor 14, and a nozzle 17 and a part of a spark plug 18 protrude from the front surface of the combustor 14.

A fuel supply pipe 19 is connected to the nozzle 17. The fuel supply pipe 19 is connected to the control board 11
Is extended to the right side of the housing 1 through the back side of the housing 1, and is bent here in a U-turn shape. On the other hand, a fuel supply device 20 including a proportional valve, a solenoid valve, and the like is attached to the rear surface of the housing 1, and the fuel supply pipe 19 is connected to the fuel supply device 20.

The fuel supply device 20 is provided with a hose joint 21 projecting outside the housing 1, and a frame rod 22 is provided on an upper surface of the combustor 14. The upper surface of the refrigerant heater 15 is provided with a protector 22 such as a thermal fuse or a thermostat for preventing overheating, and the left side of the refrigerant heater 15 is connected to an exhaust duct 23, which is attached to the front of the heat exchange chamber. The exhaust top 24 is communicated via an exhaust pipe 25.

An outdoor unit is constructed in this manner, and by driving the compressor 9, an outdoor heat exchanger is provided.
Refrigerant circulates through an indoor heat exchanger (not shown) to perform a cooling operation and the like.

During the heating operation, the refrigerant is guided to the refrigerant heater 15 of the refrigerant heating unit 13, the fuel supply device 20 is opened, the combustion blower 16 is operated, and the combustion action is performed in the combustor 14. Will be

The refrigerant guided to the refrigerant heater 15 absorbs the heat of the combustion gas and rises in temperature. Therefore, the refrigerant evaporation temperature in the refrigeration cycle increases, and the set heating temperature can be reliably obtained.

[0013]

Although there is no problem in operation as such a refrigerant heating type air conditioner,
In the configuration of the refrigerant heating unit 13, some required improvements are left.

That is, when the combustion heat of the combustion gas is applied to the refrigerant when the refrigerant heater 15 is used, the stress caused by the difference in the coefficient of thermal expansion between the copper refrigerant pipe 27 and the aluminum refrigerant heater 15 is increased. Is generated, and the influence of the stress is particularly large at the bent portion of the refrigerant pipe 27. If no countermeasure is taken against this, the fixed portion of the refrigerant pipe 27 in the refrigerant heater 15 may be loosened. Such loosening of the fixed portion also causes poor heat conduction to the refrigerant flowing through the refrigerant pipe 27, and lowers the gas combustion efficiency (thermal efficiency).

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the stress caused by the difference in the coefficient of thermal expansion between the pipe and the heat exchanger body, thereby reducing the piping. It is an object of the present invention to provide a heat exchanger that prevents a decrease in heat conductivity to a heat medium flowing through a heat exchanger.

[0016]

In order to solve the above-mentioned problems, a heat exchanger according to the present invention comprises a pipe, a pipe fixing groove for holding the pipe, and a pipe for accommodating a bent portion of the pipe. A heat exchanger having a groove communicating with the fixing groove and made of a different material from the pipe; characterized in that a gap is provided between the groove and the pipe at the bent portion. And Preferably, the gap is 0.2 mm or more.

In this heat exchanger, a gap is provided between the groove communicating with the fixing groove for accommodating the bent portion of the pipe and the pipe of the bent portion. The stress caused by the difference in the coefficient of thermal expansion between the heat exchanger body and the pipe at the time can be reduced. As a result, it is possible to prevent a decrease in the thermal conductivity to the heat medium flowing through the pipe.

It is preferable that a gap b between the pipe of the bent portion and a side face of the groove communicating with the pipe fixing groove is larger than a gap c between the pipe of the bent portion and the bottom surface of the groove. . This is because when the pipe and the heat exchanger body thermally expand,
This is because it is considered that the thermal expansion of the pipe in the gap b is larger than the thermal expansion of the pipe in the gap c.

The gap b between the pipe at the bent portion and the side surface of the groove communicating with the pipe fixing groove is preferably 1.0 mm or more. It is preferable that the gap c with the bottom surface is 0.2 mm or more.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional front view showing an outdoor unit of a refrigerant heating type air conditioner provided with a refrigerant heater according to one embodiment of the present invention. FIG. 2 (A)
FIG. 2 is a cross-sectional plan view of the outdoor unit shown in FIG.
(B) is a vertical side view of the outdoor unit shown in FIG. 1. FIG. 3A is a front view showing a refrigerant heating unit having a refrigerant heater according to one embodiment of the present invention, and FIG. 3B is a side view of the refrigerant heating unit shown in FIG. FIG. 3 (C) shows 3C-3C shown in FIG. 3 (A).
It is sectional drawing along the line. FIG. 4 is a side sectional view showing a bent portion of the refrigerant pipe of the refrigerant heating unit shown in FIG.

As shown in FIGS. 1 and 2, an outdoor unit of a refrigerant heating type air conditioner having a refrigerant heating unit 38 to be described later is constructed. The housing 30, which is the unit body,
The front view, the side view, and the top view all include a rectangular box.

The inside of the housing 30 is divided into two chambers by a partition plate 31 except for the upper part of the housing. That is, the upper edge of the partition plate 31 is spaced apart from the upper surface of the housing by a predetermined distance, and does not partition the inside of the housing 30 here.

The housing 30 partitioned by the partition plate 31
The left space inside is called an air heat exchange chamber 32 and the right space is called a machine room 33. An outdoor heat exchanger 34 and an outdoor fan 35 are arranged in the air heat exchange chamber 32. In the machine room 33, a compressor 36 and piping 37 connected to the compressor 36 are arranged, and a refrigerant heating unit 38 described later is arranged above the compressor 36.
The refrigerant heating unit 38 includes a combustor 44, a refrigerant heater 45, a fuel supply device 46, and a combustion blower 47.

The outdoor fan 35 is mounted and supported on a support table (not shown) disposed on the front side of the housing 30, and the outdoor heat exchanger 34 is disposed on the suction side. The housing 30 is provided with a suction grill and a blow grill (not shown).

In the gap between the upper edge of the partition plate 31 and the upper surface 30a of the housing 30, a part of an electrical component box 39 for accommodating electrical components and the like is interposed. That is, this electrical component box 3
9 is a refrigerant heating unit 3 arranged in the machine room 33.
8 and facing the housing upper surface 30a.

The cooling fin 4 is provided on one side of the electrical component box 39.
0a is protruded. The cooling fin 40 a is directly attached to a component that dissipates high heat, such as a G. Tr (giant transistor), out of the electrical components, and projects from the upper end edge of the partition plate 31 into the air heat exchange chamber 32. I have. Therefore, heat is radiated into the room and cooled by the air flowing through the room.

A wiring terminal plate 40b is mounted on the other side of the electrical component box 39. A wiring opening 43 that can be opened and closed by a lid 42 is provided on the upper side surface of the housing 30 facing the wiring terminal plate 40b.

A compressor 36 disposed in the machine room 33 is connected to the outdoor heat exchanger 34 via a refrigerant pipe (not shown) and is connected to an indoor heat exchanger in the indoor unit so as to form a refrigeration cycle. Is done.

As shown in FIGS. 3A and 3B, a refrigerant heater 45 is connected to a side portion of the combustor 44, and a combustion blower 47 is connected to a lower portion of the combustor 44. Fuel supply device 4
6 (shown in FIG. 2A) is connected to the back side of the combustor 44.

The combustor 44 is provided with a burner case 48 in which divided bodies 48a and 48b made of an aluminum die-cast product divided into two pieces are combined. That is,
A flange F is formed along the peripheral edge of each of the divided bodies 48a and 48b, and these flanges F are fitted to each other, and the divided bodies are screwed to each other with a mounting screw 101,
It is integrally formed as a burner case 48.

In the burner case 48, a box-shaped storage section (not shown) having an open front surface is formed, and a cover 50 for opening and closing the front opening of the storage section is provided.
A convex part 50a is attached to the front side of the lid part 50,
When the refrigerant heating unit 38 is attached to a predetermined position inside the housing 30 shown in FIG.
A gap between the housing front part 30b and the combustor 44 is secured. A burner (not shown) is attached to the back side of the lid 50.

The combustion blower 47 is provided with a combustion motor 61. The motor 61 is driven, and combustion air is sent to the combustor 44 by a fan. On the other hand, the fuel gas whose supply amount has been adjusted is sent to the combustor 44 from the fuel supply device 46.

The refrigerant heater 45 has a combustion passage (not shown) through which a combustion gas flows.
a and 48b are formed in an integrally molded interior. A pipe fixing groove 53a is provided on the outer surface of each of the divided bodies 48a and 48b, and the pipe fixing groove 53a has a refrigerant pipe 5 made of a copper pipe.
3 is fixed by caulking.

As shown in FIG. 3C, the divided body 48a is provided with the pipe fixing groove 53a as described above. A portion having a width (diameter) larger than the width (diameter) of the open portion (upper portion of the groove) is formed below the pipe fixing groove 53a. In addition, although the lower cross-sectional shape of the fixing groove 53a is substantially semicircular, to be precise, it is a shape (for example, an arc shape) obtained by cutting and enlarging the side of the semicircular groove.

The refrigerant pipe 5 is provided in the pipe fixing groove 53a.
3 is caulked by the caulking mold. The refrigerant pipe 53 has an original diameter larger than the largest diameter below the fixing groove 53a. The refrigerant pipe 53 after the caulking is fixed is in close contact with the inner surface of the fixing groove 53a. Also, the diameter of the lower part of the fixing groove 53a is
Since the diameter is larger than the diameter of the upper part a, the divided body 48a when performing heat exchange with the refrigerant pipe 53 by the refrigerant heater 45,
Even if stress occurs due to the difference in the coefficient of thermal expansion between the aluminum 48b and the copper of the refrigerant pipe 53, the refrigerant heater 45 remains tightly closed without any gap between the refrigerant pipe 53 and the fixing groove 53a. Can be used. That is, the structure is such that the refrigerant pipe 53 is not easily loosened after the caulking is fixed.

After the caulking and fixing of the refrigerant pipe 53 in the groove 53a, a convex portion is formed at an open portion (upper portion) of the fixing groove 53a. This projection is formed by a swaging type.

In the refrigerant heater 45, the refrigerant pipe 53 is turned several times by bending and fixed to the divided bodies 48a and 48b. At the bent portion of the bent refrigerant pipe 53, grooves for forming a gap between the refrigerant pipe 53 and the divided body 48a (groove forming grooves) are formed on the outer surface of the divided body 48a as shown in FIG. ) 53b are provided.
The gap forming groove 53b has a substantially semicircular planar shape as shown in FIG. 3A, and communicates with the pipe fixing groove 53a. There is a step in the portion where the fixing groove 53a and the gap forming groove 53b are connected, and the bottom of the gap forming groove 53b is formed lower than the bottom of the fixing groove 53a.

In this bent portion, a gap of a distance b is formed between the refrigerant pipe 53 and the side wall of the gap forming groove 53b, and a distance c is formed between the refrigerant pipe 53 and the bottom of the gap forming groove 53b. Are formed. The distance of the gap b is formed longer than the gap c. The gap b is preferably at least 1.0 mm, and the gap c is preferably at least 0.2 mm.

The gaps b and c are provided for the following reasons. When the combustion heat of the combustion gas is added to the refrigerant when the refrigerant heater 45 is used, the copper refrigerant pipe 5
A stress is generated due to a difference in the coefficient of thermal expansion between the aluminum pipe 3 and the aluminum divided bodies 48a and 48b. Therefore, it is necessary to relieve this stress. However, due to the gaps b and c provided in the bent portion of the refrigerant pipe 53, the heat between the aluminum divided bodies 48a and 48b and the copper refrigerant pipe 53 during thermal expansion is increased. The stress caused by the difference in expansion coefficient can be reduced.

During the heating operation, the refrigerant heating unit 3
The refrigerant is guided to the refrigerant pipe 53 of the refrigerant heater 45 of No. 8 and the fuel supply device 46 is opened, and the combustion action is performed in the combustor 44.

The refrigerant in the refrigerant pipe 53 attached to the refrigerant heater 45 absorbs the heat of the combustion gas guided from the combustor 44 along the combustion passage of the refrigerant heater 45 and rises in temperature. Therefore, the refrigerant evaporation temperature in the refrigeration cycle increases, and the set heating temperature is obtained.

[0042]

As described above, according to the present invention,
A gap is provided between the groove communicating with the pipe fixing groove for accommodating the bent portion of the pipe and the pipe of the bent portion.
Therefore, the stress caused by the difference in the coefficient of thermal expansion between the pipe and the heat exchanger body can be reduced. As a result,
It is possible to prevent a decrease in heat conductivity to the heat medium flowing through the pipe.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing an outdoor unit of a refrigerant heating type air conditioner provided with a refrigerant heater according to an embodiment of the present invention.

2A is a cross-sectional plan view of the outdoor unit shown in FIG. 1, and FIG. 2B is a vertical sectional side view of the outdoor unit shown in FIG.

FIG. 3 (A) is a front view showing a refrigerant heating unit having a refrigerant heater according to one embodiment of the present invention, and FIG. 3 (B) is a refrigerant heating unit shown in FIG. 3 (A). FIG. 3C is a side view of the unit, and FIG.
It is sectional drawing which followed the -3C line.

FIG. 4 is a side sectional view showing a bent portion of a refrigerant pipe of the refrigerant heating unit shown in FIG. 3 (A).

FIG. 5 is a block diagram showing an outdoor unit of a conventional refrigerant heating type air conditioner provided with a refrigerant heater.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Housing 2 Partition plate 3 Upper base plate 4 Heat exchange room 5 Outdoor fan 6 Machine room 7 Compressor 8 Suction cup 9 Connection piping 10 Packed valve 11 Control board 12 Connector 13 Refrigerant heating unit 14 Combustor 15 Refrigerant heater 16 Combustion blower 17 Nozzle 18 Spark plug 19 Fuel supply pipe 20 Fuel supply device 21 Hose joint 22 Frame rod 23 Exhaust duct 24 Exhaust top 25 Exhaust pipe 27 Refrigerant pipe 30 Housing 30a Upper surface 30b Housing front 31 Partition plate 32 Air Heat exchange room 33 Machine room 34 Outdoor heat exchanger 35 Outdoor fan 36 Compressor 37 Suction cup 38 Refrigerant heating unit 39 Electrical component box 40a Cooling fin 40b Wiring terminal plate 42 Lid 43 Wiring opening 44 Combustor 45 Refrigerant heater 46 Fuel supply device 47 Combustion blower 48 Burner case 48a, 48b Split body 50 Lid 50a Convex portion 53 Refrigerant pipe 53a Pipe fixing groove 53b Gap forming groove 61 Combustion motor 101 Mounting screw

Continued on the front page (72) Inventor Naozumi Yukawa 336 Tatehara, Fuji-shi, Shizuoka Prefecture Inside Fuji Plant, Toshiba Corporation (72) Inventor Naotaka Unno 336 Tatehara, Fuji City, Shizuoka Prefecture Inside Fuji Plant, Toshiba Corporation (72) Inventor Ebina 5-12-4 Honcho, Nakano-ku, Tokyo (72) Inventor Nobuyuki Goto 4-13-21 Nakameguro, Meguro-ku, Tokyo Urban Heights C-301 (72) Inventor Kiyoshi Umezawa 3- Takasago, Katsushika-ku, Tokyo 2-7-112 Takasago Apartment 112 (72) Inventor Toshio Ebihara 1687-10 Yatsukacho, Soka-shi, Saitama

Claims (4)

[Claims] 1. A material different from the pipe having a pipe, a pipe fixing groove for holding the pipe, and a groove communicating with the fixing groove for accommodating a bent portion of the pipe. A heat exchanger comprising: a gap between the groove and a pipe at a bent portion. 2. The heat exchanger according to claim 1, wherein the gap is at least 0.2 mm. 3. A gap b between the pipe of the bent portion and a side surface of the groove communicating with the pipe fixing groove is larger than a gap c between the pipe of the bent portion and the bottom surface of the groove. The heat exchanger according to claim 1, wherein 4. A gap b between a pipe of the bent portion and a side surface of a groove communicating with the pipe fixing groove is 1.0 mm or more.
2. The heat exchanger according to claim 1, wherein a gap c between a pipe of the bent portion and a bottom surface of the groove is 0.2 mm or more.