JPH09318172A - Heat exchanger for external combustion type hot-gas engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide for an external combustion type hot-gas engine a heat exchanger which facilitates the manufacture in parallel with securement of high heat-exchange efficiency. SOLUTION: In the trunk part 53 of a gas tube 50 an inner fin 55 is put in a manner of press fitting. The inner fin 55 is a product of extrusion molding of aluminum alloy, copper, or the like, comprising six fins 56 forming the shape of an asterisk, placed radially from the center at an equal angle between any adjacent two of them. Thus the passage of the gas tube 50 is divided into six equal parts. From each of two sides of each fin 56 there are three pairs of subfins 57 projecting. A number of ring-shaped outer fins 54 are formed on the outer wall 53b of the trunk part 53.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger of an external combustion type hot gas engine, which is suitable as a cold heat source for a heating / cooling device, a hot water supply device, etc. Concerning technology to plan.

[0002]

2. Description of the Related Art In recent years, as a device for cooling, heating and hot water supply,
A heat pump that uses the Vermier cycle that is an external combustion type hot gas engine (hereinafter, VMHP: Vuilleumier Cycle Heat
Pump). The VMHP causes a pressure change only by a change in the temperature distribution of He (helium) gas as an encapsulating medium (working gas), thereby enabling direct heating / cooling / hot water supply (for example, Japanese Patent Application Laid-Open No. HEI 5-5-2).
65777 or JP-A-4-113170).

[0003] The working gas circuit of the VMHP is provided with a heat exchanger in a medium temperature room or a low temperature room. The heat exchanger is a device that transfers heat energy between the working gas and the external heat medium.For example, in a medium-temperature heat exchanger, heat energy is released from the working gas to the external heat medium, and the low-temperature heat In the exchanger, the working gas absorbs the heat energy of the external heating medium.
A conventional heat exchanger includes a heat exchanger body to which a pipe for an external heat refrigerant is connected, and a gas tube arranged in the heat exchanger body, and the working gas and the external heat refrigerant are gas. It is separated by the tube wall of the tube.

[0004]

In the above-described hot gas engine, since the pressure of the working gas increases to about 10 MPa during operation, the gas tube is required to have high pressure resistance. Further, in order to improve the heat exchange efficiency, it is necessary to secure a wide heat transfer area between the working gas and the external heat refrigerant. Therefore, conventionally, a thick and small-diameter gas tube has been used, and several hundred to 1,000 tubes have been arranged in the heat exchanger body. However, when such a configuration is employed, the number of parts becomes extremely large, and the step of inserting individual gas tubes into the support holes of the heat exchanger body becomes complicated, which increases the production cost and the time required for production. Increase was inevitable.

An object of the present invention is to provide a heat exchanger for an external combustion type hot gas engine, which realizes simplification of manufacturing while ensuring high heat exchange efficiency.

[0006]

In order to solve the above-mentioned problems, the invention of claim 1 is provided on the outer periphery of a piston of an external combustion type hot gas engine, and between the working gas circuit and the external heat medium circuit. A heat exchanger that is interposed in, a cylindrical heat exchanger main body through which the external heat medium flows, a gas tube that is provided in the heat exchanger main body and is used for the flow of working gas,
The inner wall of the gas tube is provided with inner fins formed substantially along the flow direction of the working gas.

According to the present invention, the heat energy is transferred to the working gas not only by the inner wall surface of the gas tube but also by the inner fin, so that the heat exchange efficiency is improved.

Further, the invention of claim 2 is a heat exchanger which is provided on the outer periphery of a piston of an external combustion type hot gas engine and is interposed between a working gas circuit and an external heat medium circuit, A cylindrical heat exchanger main body through which the external heat medium flows, a gas tube provided in the heat exchanger main body for supplying the working gas, and a flow of the working gas on the inner wall surface of the gas tube. It is characterized in that it is provided with inner fins formed substantially along the direction and sub-fins formed on the surface of the inner fins.

According to the present invention, the heat energy is transferred to the working gas by the inner fins and the sub fins, and the heat exchange efficiency is further improved.

Further, according to the invention of claim 3, a heat exchanger main body, which is interposed between the working gas circuit of the external combustion type hot gas engine and the external heat medium circuit, and through which the external heat medium flows, In a heat exchanger having a gas tube provided in the heat exchanger main body and used for circulation of a working gas, inner fins are formed on an inner wall surface of the gas tube so as to be substantially along a flow direction of the working gas. An outer fin is formed on the outer wall surface of the gas tube so as to extend substantially along the flow direction of the external heat medium.

According to the present invention, the heat energy is transferred to the working gas by the inner fins, while the heat energy is transferred to the external heat refrigerant by the outer fins, and the heat exchange efficiency is further improved. .

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a cold / hot water supply circuit of an air conditioner, which employs a Vilmier cycle hot gas engine 1 whose sectional perspective is shown in FIG. The hot gas engine 1 includes a high-temperature-side piston 2 and a low-temperature-side piston 3 arranged orthogonally to each other, and these are housed in a container in which a working gas such as helium is sealed. The inside of the container is partitioned into a high-temperature chamber 12, medium-temperature chambers 13 and 14, and a low-temperature chamber 15. Further, a heater 16 is provided at the end of the high temperature chamber 12, and the heater 16 is heated by the combustor 11.

When the high temperature side piston 2 reaches an intermediate position between the top dead center and the bottom dead center, for example,
The low-temperature side piston 3 is positioned 9
In order to operate with a phase shift of 0 °, they are connected via a crank 10 driven by a motor 9. When the high-temperature side piston 2 and the low-temperature side piston 3 operate, the enclosed working gas passes through the high-temperature regenerator 4 and the low-temperature regenerator 7 and each chamber 1
Move between 2 and 13, 14 and 15. Then, the working gas is heated or cooled when passing through the regenerators 4 and 7, so that the pressure inside the closed container is increased or decreased.

For example, when the working gas in the high temperature chamber 12 moves to the middle greenhouse 13 through the high temperature regenerator 4, the thermal energy of the working gas is stored in the high temperature regenerator 4 and the pressure of the working gas decreases. . Conversely, when the working gas circulates from the middle greenhouse 13 to the high temperature chamber 12, the thermal energy stored in the high temperature regenerator 4 is released to the working gas, and the pressure of the working gas rises. When the working gas in the low-temperature chamber 15 moves to the medium-temperature chamber 13 through the low-temperature regenerator 7, the working gas is supplied with the thermal energy of the high-temperature regenerator 4, and the pressure of the working gas also increases. On the contrary, when the working gas is recirculated from the middle greenhouse 13 to the low temperature chamber 15, the thermal energy of the working gas is changed to the low temperature regenerator 4.
And the pressure of the working gas decreases.

The exchange of heat energy with the outside is performed by the medium temperature heat exchangers 5 and 6 connected to the intermediate greenhouses 13 and 14 and the low temperature heat exchanger 8 connected to the low temperature chamber. For example, when the heater 16 gives thermal energy to the working gas in the high temperature chamber 12, the working gas in the medium temperature chambers 13 and 14 emits heat energy to the external heat medium via the medium temperature heat exchangers 5 and 6, and The working gas in the low-temperature chamber 15 absorbs heat energy from the external heat medium through the low-temperature heat exchanger 8.

That is, in the hot gas engine 1 of the present embodiment, the low-temperature heat exchanger 8 and the low-temperature chamber 15 constitute a heat absorbing portion, while the medium-temperature heat exchangers 5 and 6 and the medium-temperature chambers 13 and 14 radiate heat. The air conditioner 100 which constitutes a part and uses the low temperature heat exchanger 8 and the medium temperature heat exchangers 5 and 6 of the hot gas engine 1 is provided. The air conditioner 100 includes a hot gas engine 1, an indoor unit 200, and an outdoor unit 300.

An indoor heat exchanger 201 is provided in the indoor unit 200, and an outdoor heat exchanger 300 is provided in the outdoor unit 300. Reference numeral 203 is an indoor fan, and 303 is an outdoor fan. The low-temperature heat exchanger 8 and the indoor heat exchanger 201 are connected by the pipe 21, the four-way valve 36, and the pipe 22, and the indoor heat exchanger 201 and the low-temperature heat exchanger 8 are connected by the pipe 23 and the four-way valve 37. It is connected to the pipeline 24. Also,
The intermediate heat exchanger 5 and the outdoor heat exchanger 301 are connected by a pipe 31, a four-way valve 36 and a pipe 32, and the outdoor heat exchanger 301 and the intermediate heat exchanger 6 are further connected by a pipe 33 and a four-way valve 37.
And a conduit 34. The medium temperature heat exchangers 5 and 6 are connected to each other by a pipe line 35. Water (hereinafter, referred to as liquid refrigerant) is used as an external heat medium circulating in the pipeline.

During the cooling operation, the hot gas engine 1 is operated by the ignition of the combustor 11, and the heat energy of the working gas is released to the liquid refrigerant through the medium temperature heat exchangers 5, 6, while the low temperature heat exchanger is operated. The heat energy of the liquid refrigerant is absorbed by the working gas through the pipe 8. At this time, the four-way valves 36 and 37 are switched as shown by the solid line in FIG. 1, and the liquid refrigerant that has released the heat energy in the low-temperature heat exchanger 8 is the pipe line 21 and the four-way valve 3
6, it flows into the indoor heat exchanger 201 via the pipe line 22.
In the indoor unit 200, the indoor heat exchanger 201 becomes low in temperature.
Is blown from the indoor fan 203, cool air is blown into the room (cooling is performed), and the liquid refrigerant that has absorbed the heat energy of the room air passes through the pipe 23, the four-way valve 37, and the pipe 24. It recirculates to the low-temperature heat exchanger 8.

At this time, the liquid refrigerant having absorbed the heat energy in the intermediate-temperature heat exchanger 5 is supplied to the pipe 31, the four-way valve 36, and the pipe 32.
To the outdoor heat exchanger 301, where it is cooled by the air blown from the outdoor fan 303, then flows to the intermediate temperature heat exchanger 6 through the conduit 33, the four-way valve 37, and the conduit 34, and further through the conduit 35. Return to vessel 5.

Also, during the heating operation, the hot gas engine 1 is operated by the ignition of the combustor 11, and the heat energy of the working gas is absorbed by the liquid refrigerant through the medium-temperature heat exchangers 5 and 6, while the low-temperature The heat energy of the liquid refrigerant is released to the working gas via the heat exchanger 8, and at this time, the four-way valves 36 and 37 are switched as shown by the dotted lines in FIG. In this case, the liquid refrigerant that has absorbed the heat energy in the medium-temperature heat exchangers 5, 6 is:
It flows to the indoor heat exchanger 201 via the pipe 31, the four-way valve 36, and the pipe 22. In the indoor unit 200, air is blown from the indoor fan 203 to the indoor heat exchanger 201, which has become relatively hot, and hot air is blown into the room (heating is performed), while heat energy is released into the room. The liquid refrigerant flows through the pipe 23, the four-way valve 37, and the pipe 34 to the intermediate-temperature heat exchangers 5 and 6.

At this time, the liquid refrigerant which has released the heat energy in the low temperature heat exchanger 8 is the pipe 21, the four-way valve 36 and the pipe 32.
To the outdoor heat exchanger 301, where after the heat energy of the outside air is absorbed by the air blown from the outdoor fan 303, it is circulated to the low temperature heat exchanger 8 via the pipe 33, the four-way valve 37 and the pipe 24.

Embodiments of Heat Exchanger Embodiments of the medium temperature heat exchangers 5 and 6 and the low temperature heat exchanger 8 will be described below. Both heat exchangers 5, 6 and 8 have substantially the same configuration. Therefore, a specific description will be given only to the medium-temperature heat exchanger (hereinafter, simply referred to as a heat exchanger) 5.

FIG. 3 shows a perspective view of a first embodiment of the heat exchanger 5 according to the present invention, and FIG. 4 shows a longitudinal section thereof.

As shown in these figures, the heat exchanger 5
Is the high temperature side piston 2 (or the low temperature side piston 3)
Has a cylindrical shape having a cylindrical hole 40 that reciprocates in the center. The heat exchanger body 41 of the heat exchanger 5 includes a cylindrical outer sleeve 42 and inner sleeve 43, and annular upper and lower tube plates 44 and 45, which are joined by brazing. . Outer sleeve 42
A refrigerant inflow port 46 and a refrigerant outflow port 47 are formed at 180 ° intervals in the vertical central part of the liquid refrigerant flowing from the refrigerant inflow port 46 into the heat exchanger body 41.
Outflow from 7. Further, in the upper and lower tube plates 44 and 45, a large number (52 in the present embodiment) of tube support holes 48,
49 is bored at the same position, and a gas tube 50 having a relatively large diameter shown in FIG.
Is supported.

The gas tube 50 is made of a copper pipe, and the diameter of the intermediate portion 53 excluding the insertion portions 51 and 52 into the upper and lower tube plates 44 and 45 is reduced. The inner wall surface 53a of the middle portion 53 of the gas tube 50 is finished to be smooth, but the outer wall surface 53b has an annular outer fin as shown in FIG. 6 (enlarged view of portion A in FIG. 5). 54
Are formed in large numbers. In the present embodiment, the outer fins 54 are formed by rolling at the same time as the diameter reduction of the intermediate portion 53, but they may be formed by a method such as cutting or press-fitting another component.

In the case of the first embodiment, the inner fins 55 are press-fitted into the intermediate portion 53 of the gas tube 50.
The inner fin 55 is an extrusion-molded product of aluminum alloy, copper, or the like, and as shown in FIG. 7 (BB enlarged cross-sectional view in FIG. 5), the six fin portions 56 are radially arranged at equal angles from the center. It is arranged in an outer risk (*) shape, whereby the pipeline of the gas tube 50 is divided into six equal parts. Further, three pairs of sub fins 57 are provided on both side surfaces of each fin portion 56 so as to project therefrom.

In the heat exchanger 5 of this embodiment, when the operation of the hot gas engine 1 is started, the working gas in the gas tube 50 is not limited to the inner wall surface 53a of the intermediate portion 53 but also the fin portion of the inner fin 55. It also flows while contacting 56 and the sub fin 57. Further, the liquid refrigerant in the heat exchanger body 41 flows not only on the outer wall surface 53b of the intermediate portion 53 but also on the outer fin 54 while contacting the outer fin 54. As a result, in the heat exchanger 5 of the present embodiment, a large heat transfer area is ensured between the working gas and the external heat refrigerant, even though the number of gas tubes 50 is small, and the heat is equal to or higher than that of the conventional device. The exchange efficiency could be realized.

8 to 10 show cross sections of gas tubes according to second to fourth embodiments of the present invention. In the second and third embodiments, the inner fins 55 are press-fitted into the gas tube 50 as in the first embodiment. The inner fin 55 in the second embodiment is made of a relatively thin copper pipe, and is formed into a clover shape by press working or the like. In addition, the inner fin 55 in the third embodiment is an extruded product of aluminum alloy, copper or the like as in the first embodiment, and has a cross shape that divides the pipeline of the gas tube 50 into four equal parts. On the other hand, the inner fin 55 in the fourth embodiment is the gas tube 50.
Is directly machined on the inner wall surface 53a, and is similar to the spiral groove formed on the inner peripheral surface of a so-called internal grooved tube. In addition, also in the second to fourth embodiments, a large number of annular outer fins 54 are formed on the outer wall surface 53b of the intermediate portion 53 of the gas tube 50.

The operation of the second to fourth embodiments is substantially the same as that of the first embodiment. That is, the inner fins 55 and the outer fins 54 ensure a large heat transfer area between the working gas and the external heat refrigerant, and realize the heat exchange efficiency equal to or higher than that of the conventional device despite the small number of the gas tubes 50. We were able to.

The description of the specific embodiment has been completed.
The present invention is not limited to the embodiments described above.
For example, in the first to third embodiments, the inner fins are press-fitted into the gas tube, but they may be integrated by brazing, diffusion bonding, or the like. In addition to the cross-sectional shape and overall shape of the inner fin (for example, spiral shape), the number of gas tubes and the outer diameter, etc.
It can be appropriately changed depending on the ease of manufacture and the required heat exchange efficiency. Further, stainless steel, aluminum alloy or the like may be used as the material of the gas tube, and copper or stainless steel or the like may be used as the material of the inner fin or the outer fin. Further, the heat exchanger of the present invention is applicable to an external combustion type hot gas engine other than the Vermier cycle, such as a Stirling engine.

[0032]

As described above, according to the heat exchanger of the present invention, the inner fins are arranged on the inner wall surface of the gas tube arranged in the tubular heat exchanger body so as to be substantially along the flow direction of the working gas. Since it is formed, it is possible to reduce the number of gas tubes while ensuring high heat exchange efficiency,
It is possible to realize simplification of manufacturing and reduction of manufacturing cost.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of a heat pump type air conditioner.

FIG. 2 is a sectional perspective view showing a structure of a hot gas engine.

FIG. 3 is a perspective view showing an embodiment of the heat exchanger.

FIG. 4 is a vertical view showing an embodiment of a heat exchanger.

FIG. 5 is a half-cut sectional view of the gas tube according to the first embodiment.

FIG. 6 is an enlarged view of part A in FIG.

FIG. 7 is a sectional view taken along the line BB in FIG. 5;

FIG. 8 is a cross-sectional view of a gas tube according to a second embodiment.

FIG. 9 is a cross-sectional view of a gas tube according to a third embodiment.

FIG. 10 is a cross-sectional view of the gas tube according to the second embodiment.

[Explanation of symbols]

 1 Hot Gas Engine 5, 6 Medium Temperature Heat Exchanger 8 Low Temperature Heat Exchanger 40 Tube Hole 41 Heat Exchanger Main Body 42 Outer Sleeve 43 Inner Sleeve 44, 45 Tube Plate 50 Gas Tube 53 Middle Section 53a Inner Wall Surface 53b Outer Wall Surface 54 Outer Fin 55 Inner fin 56 Fin part 57 Sub fin

Claims (3)

[Claims] 1. A heat exchanger, which is provided on the outer circumference of a piston of an external combustion type hot gas engine and is interposed between a working gas circuit and an external heat medium circuit, in which the external heat medium flows. -Shaped heat exchanger main body, a gas tube provided in the heat exchanger main body for supplying working gas, and formed on the inner wall surface of the gas tube so as to be substantially along the flow direction of the working gas. And a heat exchanger for an external combustion type hot gas engine. 2. A heat exchanger, which is provided on the outer circumference of a piston of an external combustion heat gas engine and is interposed between a working gas circuit and an external heat medium circuit, in which the external heat medium flows. -Shaped heat exchanger main body, a gas tube provided in the heat exchanger main body for supplying working gas, and formed on the inner wall surface of the gas tube so as to be substantially along the flow direction of the working gas. And a sub-fin formed on the surface of the inner fin, the heat exchanger for an external combustion type hot gas engine. 3. A heat exchanger which is provided on the outer circumference of a piston of an external combustion type hot gas engine and is interposed between a working gas circuit and an external heat medium circuit, in which the external heat medium flows. -Shaped heat exchanger main body, a gas tube provided in the heat exchanger main body for supplying working gas, and formed on the inner wall surface of the gas tube so as to be substantially along the flow direction of the working gas. A heat exchanger of an external combustion type hot gas engine, comprising: the inner fin and an outer fin formed on an outer wall surface of the gas tube so as to substantially follow a flow direction of the external heat medium.