WO2005098336A1

WO2005098336A1 - Evaporator, themosiphon, and stirling cooling chamber

Info

Publication number: WO2005098336A1
Application number: PCT/JP2005/005525
Authority: WO
Inventors: Henglang Zhang
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2004-03-30
Filing date: 2005-03-25
Publication date: 2005-10-20
Also published as: JP2005283022A

Abstract

An evaporator is formed, having an inflow opening from which a liquid or substantially liquid refrigerant flows in, heat exchanging piping for evaporating the refrigerant, and an outflow opening from which the refrigerant flows out. The inflow opening, heat exchanging piping, and outflow opening are connected in that order, and at least a part of the heat exchanging piping is branched off into lines of parallel internal piping.

Description

Specification

Evaporator, thermosiphon and Stirling cooler

Technical field

The present invention relates to an evaporator used in a secondary refrigerant circuit, a loop thermosiphon using the evaporator, and a Stirling cooler using the loop thermosiphon.

Background art

[0002] Reverse Stirling refrigeration cycles have recently attracted attention. The reverse Stirling refrigeration cycle employs a working gas, such as helium gas, hydrogen gas, or nitrogen gas, which does not adversely affect the global environment. A Stirling refrigerator using this reverse Stirling refrigeration cycle is known as one of small refrigerators capable of generating extremely low-temperature refrigeration. The Stirling refrigerator has a high-temperature section called a warm section and a low-temperature section called a cold head, depending on the shape and size of the internal heat exchange provided therein.

[0003] As a method of transporting the cold generated in the low-temperature portion of the Stirling refrigerator to the cooling chamber, a condenser filled with a refrigerant is attached to the low-temperature portion, and an evaporator provided below the condenser ( Cooler) is connected by pipes, and natural circulation heat exchange is used. As the natural circulation type heat exchange, a secondary refrigerant circulation circuit in which a secondary refrigerant is sealed can be exemplified.

[0004] In the secondary refrigerant circulation circuit, a condenser attached to the low-temperature section and an evaporator disposed in the refrigerator below the condenser are connected by two refrigerant circulation pipes. . The secondary refrigerant circulation circuit in which the secondary refrigerant is sealed is a thermosiphon-type natural circulation circuit using a phase change of the secondary refrigerant.

[0005] The secondary refrigerant in the secondary refrigerant circulation circuit comes into contact with the low-temperature portion of the Stirling refrigerator and is liquefied by a condenser and flows down to the evaporator. The liquid secondary refrigerant that has flowed into the evaporator undergoes heat exchange when passing through the evaporator and changes to vapor.

[0006] The secondary refrigerant that has turned into a vapor is a phenomenon in which the vapor rises, and the vapor turns into a liquid in the condenser. Due to the pressure difference due to the specific gravity difference when changing, and the pressure difference generated when the liquid secondary refrigerant flows down to the evaporator, the secondary refrigerant is sucked, rises and flows into the condenser. By repeating the above-described phase change and flow of the secondary refrigerant, the cold heat of the low-temperature part can be continuously conveyed into the Stirling cooler.

[0007] This secondary refrigerant circulation circuit utilizes natural circulation that occurs in the cooling circuit, and does not require a device such as a circulation pump for forcibly circulating the refrigerant, and thus can save energy. .

[0008] The evaporator has a heat exchange pipe for causing a secondary refrigerant to flow therein to exchange heat with external air. When heat is exchanged between the secondary refrigerant and the air in the cooling chamber in the evaporator, the cold heat of the secondary refrigerant flowing inside the heat exchange pipe is easily released to the outside. At the same time, cooling fins with high thermal conductivity are attached to the side of the heat exchange pipe. By attaching the fins, the air in the cooling chamber and the secondary refrigerant are cooled by the secondary refrigerant, thereby increasing the contact area (hereinafter, the heat exchange area) between the members (heat exchange pipes and cooling fins). can do.

[0009] In order to increase the amount of heat exchanged between the secondary refrigerant and the internal air, it is necessary to increase the length of the heat exchange pipe by increasing the heat exchange area. it can. However, the space inside the Stirling cooler is a limited space, and the evaporator is small!ヽ. Long!熱 The heat exchange pipe is arranged in a meandering manner in order to house the heat exchange pipe in the compact evaporator. In addition, the natural circulation circuit can be widely used as a heat exchanger in addition to conveying cold heat in a low-temperature portion of a Stirling refrigerator.

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-148813

Patent Document 2: JP-A-6-193920

Patent Document 3: JP 2001-33139 A

Disclosure of the invention

Problems to be solved by the invention

[0010] However, if the length of the heat exchange pipe is increased in order to secure a sufficient heat exchange area, the flow resistance due to the length of the pipe is increased, and the smooth flow of the refrigerant is hindered. Also, Since the heat exchange pipe is arranged in a meandering manner, the heat exchange pipe has a bent or curved portion. These bends and / or bends are provided with a large number of bends and / or bends having a large flow resistance to prevent smooth flow of the refrigerant.

When the flow of the refrigerant is not smoothly performed, the circulation of the refrigerant in the natural circulation circuit including the evaporator is deteriorated, or the refrigerant flows backward, so that the ability to transport cold heat is reduced. In other words, the cold generated in the low temperature part of the Stirling refrigerator cannot be efficiently transported into the cooling chamber. By attaching a forced circulation device such as a pump to the natural circulation circuit, a smooth flow of the refrigerant can be performed, but more energy is required for the power for moving the forced circulation device.

[0012] Therefore, the present invention uses an evaporator in which the refrigerant flows smoothly and heat exchange between the refrigerant and the air near the evaporator is performed with high performance and high efficiency, and the evaporator is used. It is an object to provide a loop-type thermosiphon and a cooler using the loop-type thermosiphon.

Means for solving the problem

[0013] In order to achieve the above object, the present invention provides an inflow port through which a liquid or substantially liquid refrigerant flows, a heat exchange pipe for evaporating the refrigerant, and an outflow port through which the refrigerant flows out. Wherein the inflow port, the heat exchange pipe, and the outflow port are connected in this order, and at least a part of the heat exchange pipe has a plurality of parallel internal pipes. The evaporator is provided.

[0014] According to this configuration, since the heat exchange pipe inside the evaporator has a plurality of parallel internal pipes, the total length of the pipe through which the refrigerant flows can be increased, and the heat exchange area increases accordingly. be able to. In addition, since the flow length of the refrigerant is the same or substantially the same as when the branch does not branch, the flow resistance due to the length of the pipe can be reduced, and the refrigerant flows smoothly.

[0015] With this, the evaporator can increase the heat exchange area while suppressing the flow resistance of the refrigerant, so that heat can be efficiently exchanged with the air outside the evaporator (cooling the air). It comes out.

[0016] In the above-described configuration, the inlet may be arranged below the outlet. According to this configuration, the refrigerant flows into the evaporator in a state of a liquid or a substantially liquid having a large specific gravity, evaporates in the evaporator, and flows out as a high-temperature vapor state refrigerant. Flow efficiently within the heat exchange pipe. Thereby, heat can be efficiently exchanged with the air outside the evaporator (air is cooled).

In the above configuration, the heat exchange pipe may have an internal pipe branched in a vertical direction.

According to this configuration, since the heat exchange pipe branches in the vertical direction, the evaporator can be formed thin.

[0020] In the above configuration, the heat exchange pipe may have an internal pipe branched in a horizontal direction.

According to this configuration, since the heat exchange pipe branches in the horizontal direction, the height of the evaporator can be reduced.

[0022] Examples of the use of the evaporator include, for example, those used as an evaporator of a loop-type thermosiphon. Further, an example in which the loop-type thermosiphon is used as a secondary refrigerant circulation circuit of a Stirling cooler using a Stirling refrigerator can be shown.

According to this configuration, the refrigerant inside the loop-type thermosiphon can be smoothly circulated. Further, by using the loop-type thermosiphon as a secondary refrigerant circulation circuit of the Stirling refrigerator, it is possible to efficiently transfer the cold heat of the low temperature part of the Stirling refrigerator to the inside of the refrigerator.

[0024] One or more cooling chambers may be provided inside the Stirling cooler. In this case, a cooling room, such as a refrigerator room, a freezer room, a warm room, or a cool room, which cools to a temperature range in which a Stirling refrigerator can be generated, can be widely used.

The invention's effect

According to the present invention, an evaporator is used in which a refrigerant flows smoothly and heat exchange between the refrigerant and air in the vicinity of the evaporator is performed with high performance and high efficiency. An object is to provide a loop-type thermosiphon and a cooler using the loop-type thermosiphon. Target.

Brief Description of Drawings

FIG. 1A is an enlarged front view of the inside of an evaporator according to the present invention.

FIG. 1B is an enlarged view of a cooling fin provided in the cooling-side evaporator shown in FIG. 1A.

FIG. 2A is an enlarged plan view of the inside of an evaporator according to the present invention.

FIG. 2B is an enlarged front view of the evaporator shown in FIG. 2A.

FIG. 2C is an enlarged view of a cooling fin provided in the evaporator shown in FIGS. 2A and 2B.

FIG. 3 is a schematic layout diagram of a loop type thermosiphon using the evaporator shown in FIG. 1A.

4 is a schematic diagram of a Stirling cooler using the loop thermosiphon shown in FIG. 3 as a secondary refrigerant circuit.

Explanation of symbols

[0027] 1 Evaporator

11 Inlet

12 Outlet

13 Heat exchange piping

131 Branch

132, 133 Internal piping

134 junction

14 Cooling fin

21 Liquid refrigerant piping

22 Steam refrigerant piping

3 Evaporator

33 Heat exchange piping

331 Branch

332, 333 Internal piping

334 junction

4 Loop type thermosiphon (secondary refrigerant circuit) 61 Cooling room

62 Machine Room

63 Insulated wall

631 cushioning material

7 Stirling refrigerator

71 Low temperature part

72 High temperature part

8 Radiation side natural circulation circuit

81 Radiation side evaporator

82 Radiation side condenser

83 Heat dissipation circuit

84 Ventilation fan

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1A is a sectional view of the evaporator according to the present invention, and FIG. 1B is an enlarged view of a cooling fin of the evaporator shown in FIG. 1A. The evaporator 1 shown in FIG.1A has an inlet 11 through which the refrigerant flows in, an outlet 12 through which the refrigerant flows out, and a heat exchange pipe 13 for exchanging heat between the inflowing refrigerant and external air. ing. The inflow port 11, the heat exchange pipe 13, and the outflow port 12 are airtightly connected in this order.

[0029] The inflow port 11 is connected to a liquid refrigerant pipe 21 provided outside, through which a liquid refrigerant flows. The outlet 12 is connected to a vapor refrigerant pipe 22 through which the vaporized refrigerant flows. In the evaporator 1, the inlet 11 is disposed below the outlet 12.

[0030] The heat exchange pipe 13 is connected to the inlet 11 at the upstream end, and is connected to the outlet 12 at the downstream end. The heat exchange pipe 13 has a branch 131 on the upstream side, and has two parallel internal pipes 132 and 133. Further, the internal pipes 132 and 133 have a junction 134 on the downstream side, and join at the junction 134 and connect to the outlet 12. The internal pipes 132 and 133 are vertically arranged in parallel. The two internal pipes 132 and 133 are folded without crossing Is returning.

[0031] As shown in FIGS. 1A and IB, cooling pipes are provided in the internal pipes 132 and 133 so that heat is effectively exchanged between the refrigerant flowing in the pipes and the air around the evaporator 1. 14 are installed. The cooling fins 14 are not limited to this, but here, both of the internal pipings 132 and 133 pass through one cooling fin 14. By arranging the cooling fins 14 in this manner, the heat exchange area can be increased, and at the same time, the internal pipes 132 and 133 can be prevented from contacting each other, and can act as reinforcement for increasing the strength against deformation.

[0032] Since the liquid refrigerant flowing from the inlet 11 has a higher specific gravity, the vapor refrigerant flowing out of the outlet 12 has a lower specific gravity, the inlet 11 is disposed below the outlet 12, so that the heat exchange is performed. The refrigerant flows through the exchange pipe 13 smoothly. Further, inside the evaporator 1, the liquid refrigerant having a high specific gravity moves downward, and the liquid refrigerant vaporizes and the vapor refrigerant having a low specific gravity moves upward. Accordingly, since the inlet 11 into which the liquid refrigerant flows in is disposed below the outlet 12 from which the vapor refrigerant flows out, the vapor refrigerant can be prevented from flowing back through the liquid refrigerant pipe 21, and the refrigerant Can be circulated smoothly.

[0033] The total length of the heat exchange pipe 13 can be increased by having the two internal pipes 132 and 133 in parallel with the heat exchange pipe 13. In addition, since the internal pipes 132 and 133 are arranged in parallel, it is possible to suppress an increase in the length of the flow path through which the refrigerant flows. In addition, when the total length of the heat exchange pipes is the same, the number of turns in the flow path of the refrigerant can be reduced as compared with the pipes arranged in series. Thereby, the flow resistance due to the return of the pipe can be reduced.

[0034] The use of the evaporator 1 has a large heat exchange area and a high heat exchange efficiency due to the long overall length of the heat exchange pipe 13, and has a low flow resistance in the refrigerant flow path. It can flow smoothly and efficiently exchange heat with the air around the evaporator 1 (cool the surrounding air). Further, the evaporator 1 of the present embodiment branches the internal pipes 132 and 133 in the vertical direction, so that the thickness in the width direction can be suppressed. As a result, it is possible to provide a compact evaporator 1 without reducing the heat exchange capacity.

[0035] At least one of the branching portion 131 and the merging portion 134 may be formed so as to reduce flow resistance. As a result, the refrigerant can flow smoothly, and the heat exchange effect of the evaporator 1 can be improved. Rate can be increased. Also,

FIG. 2A is an enlarged plan view of the internal shape of the cooling-side evaporator of the Stirling refrigerator according to the present invention, FIG. 2B is an enlarged front view of the internal shape of the cooling-side evaporator shown in FIG. 2A, and FIG. FIG. 2B is an enlarged view of a cooling fin of the cooling-side evaporator shown in FIGS. 2A and 2B.

[0037] The evaporator 3 shown in Figs. 2A, 2B, and 2C is one in which the heat exchange pipe 33 is branched in the horizontal direction. The other parts are the same as those of the evaporator 1 shown in FIG. 1, and the substantially same parts are denoted by the same reference numerals.

As shown in FIGS. 2A and 2B, the heat exchange pipe 33 is connected to the inlet 31 at the upstream end, and is connected to the outlet 32 at the downstream end. The heat exchange pipe 33 has a branch portion 331 on the upstream side, and has two parallel internal pipes 332 and 333. Further, the internal pipes 332 and 333 have a junction 334 on the downstream side, and join at the junction 334 and connect to the outlet 32.

[0039] Accordingly, the entire length of the heat exchange pipe 33 through which the refrigerant flows increases, that is, the heat exchange area increases. In addition, since the internal pipes 332 and 333 are arranged in parallel, it is possible to suppress an increase in the length of the flow path through which the refrigerant flows. Further, when the total length of the heat exchange pipes is the same, the number of times the refrigerant is turned back in the flow path of the refrigerant can be reduced as compared with the pipes arranged in series. Thereby, the flow resistance due to the return of the pipe can be reduced.

[0040] As shown in Figs. 2A and 2B, the internal pipes 332 and 333 are provided with cooling fins so that heat can be exchanged effectively between the refrigerant flowing in the pipes and the air around the evaporator 3. 34 are attached. The cooling fins 34 are not limited to this, but here, both the internal pipes 332 and 333 pass through one cooling fin 34 (see FIG. 2C). By arranging the cooling fins 34 in this manner, the heat exchange area can be increased, and at the same time, the internal pipes 332, 333 can be prevented from contacting each other, and can act as reinforcement for increasing the strength against deformation.

[0041] The evaporator 3 has a large heat exchange area and a high heat exchange capacity due to the long overall length of the heat exchange pipe 33, and the refrigerant flows smoothly because the flow resistance in the refrigerant flow path is small. It is possible to efficiently exchange heat with the air around the evaporator 3 (cool the surrounding air). Since the internal pipes 332 and 333 are branched in the horizontal direction, the height in the vertical direction can be suppressed. As a result, compactness without reducing heat exchange capacity It is possible to provide an efficient evaporator 3.

[0042] In each of the above-described embodiments, the number of force branching lines exemplifying a case where the internal pipe is branched into two pipes is not limited to two, and may be further branched. The internal pipe of the cooling-side evaporator is branched in the up-down direction and the left-right direction, for example, but is not limited thereto, but may be branched in both the up-down and left-right directions.

FIG. 3 shows a schematic layout diagram of a loop-type thermosiphon using the evaporator shown in FIG. 1A. The loop-type thermosiphon 4 has an evaporator 1, a condenser 5, a liquid refrigerant pipe 21, and a vapor refrigerant pipe 22. The condenser 5 is arranged above the evaporator 1. A liquid refrigerant pipe 21 and a vapor refrigerant pipe 22 are hermetically connected to the condenser 5. The evaporator 1 has an inlet 11 connected to a liquid refrigerant pipe 21 and an outlet 12 connected to a vapor refrigerant pipe 22. The inside of the loop type thermosiphon 4 is filled with a refrigerant.

[0044] A cooling device (for example, a cooling fan) not shown is provided outside the condenser 5 to cool the refrigerant inside the condenser 5. The refrigerant cooled by the condenser 5 flows down through the liquid refrigerant pipe 21 and flows into the inlet 11 of the evaporator 1. The liquid refrigerant flowing into the inlet 11 of the evaporator 1 flows inside the heat exchange pipe 13. At this time, the liquid refrigerant flows into the internal pipes 132 and 133 at the branch portion 131 and flows. The liquid refrigerant flowing through the internal pipes 132 and 133 exchanges heat with the air outside the evaporator 1 (the air is cooled) and is heated and evaporated. The evaporated refrigerant merges at the junction 134 and flows into the vapor refrigerant pipe 22 from the outlet 12. The vapor refrigerant rises in the vapor refrigerant pipe 22 and flows into the condenser 5 due to the power of the high-temperature vapor rising and the pressure fluctuation due to the change in specific gravity when changing from gas to liquid in the condenser 5. By repeating this operation, the refrigerant can be circulated inside the loop type thermosiphon 4 without using a forced circulation device such as a pump.

[0045] In the evaporator 1, since the heat exchange pipe 13 has two parallel internal pipes 132 and 133, the total length of the pipes through which the refrigerant flows can be lengthened. By being in parallel, pressure loss can be kept low, and heat exchange with the outside air can be performed efficiently.

FIG. 4 shows a schematic diagram of a stirling cooler using the loop type thermosiphon shown in FIG. 3 as a secondary refrigerant circulation circuit. The Stirling cooler A shown in FIG. Loop type thermosiphon 4 (secondary refrigerant circulation circuit) that conveys the cold generated by one ring refrigerator 7 and Stirling refrigerator 7 to the inside of the refrigerator, and transports the heat generated by Stirling refrigerator 7 to the outside of the refrigerator. The heat radiation side natural circulation circuit 8 is provided.

[0047] The main body 6 has a cooling chamber 61 for accumulating cold heat therein to cool articles, and a machine chamber 62 for disposing the Stirling refrigerator 7 therein. The machine room 62 is arranged above the cooling room 61, and the cooling room 61 and the machine room 62 are separated by a heat insulating wall 63. The Stirling refrigerator 7 is mounted on a heat insulating wall 63 via a buffer member 631. This prevents the vibration generated in the starling refrigerator 7 from being transmitted to the heat insulating wall 63.

[0048] The Stirling refrigerator 7 has a low-temperature section 71 that generates cold heat and a high-temperature section 72 that generates warm heat. The low-temperature section 71 has the loop-type thermosiphon 4 attached thereto, and the high-temperature section 72 has the radiation-side natural circulation circuit 8 attached thereto.

[0049] Secondary refrigerant circulation circuit 4 includes condenser 5 connected to low-temperature section 71, evaporator 1 provided in cooling chamber 61, liquid refrigerant pipe 21, and vapor refrigerant pipe 22. ing. Connection of the condenser 5, the evaporator 1, the liquid refrigerant pipe 21 and the vapor refrigerant pipe 22 is the same as that of the loop type thermosiphon shown in FIG. That is, the liquid refrigerant pipe 21 and the vapor refrigerant pipe 22 are airtightly connected to the condenser 5. Further, the liquid refrigerant pipe 21 and the inflow port 11 of the evaporator 1 are airtightly connected. Further, the vapor refrigerant pipe 21 and the outlet 12 of the evaporator 1 are airtightly connected. The loop type thermosiphon 4 is formed by filling the secondary refrigerant.

In the loop-type thermosiphon 4, the secondary refrigerant in the condenser 5 is cooled and liquefied by the cold heat of the low-temperature section 71. The liquefied secondary refrigerant flows down the liquid refrigerant pipe 21 and flows into the inlet 11 of the evaporator 1. The liquid secondary refrigerant that has flowed into the evaporator 1 absorbs heat from the air inside the cooling chamber 61 (cools the internal air) inside the evaporator 1 and is heated and evaporated. The evaporated secondary refrigerant flows into the vapor refrigerant pipe 22 from the outlet 12. The vapor refrigerant rises in the vapor refrigerant pipe 22 and flows into the condenser 5 due to a phenomenon in which the high-temperature vapor rises and a pressure change due to a change in specific gravity when the refrigerant changes from a gas to a liquid in the condenser 5. By repeating this operation, the secondary refrigerant circulates inside the loop type thermosiphon 4 without using a forced circulation device such as a pump. The natural circulation circuit 8 on the heat radiation side is arranged such that the evaporator 81 on the heat radiation side contacts the high temperature part 72 of the Stirling refrigerator 7 and is A hot side condenser 82 is arranged. The heat radiation side evaporator 81 and the heat radiation side condenser 82 are connected by a heat radiation circuit 83 to form a natural circulation circuit. The heat radiation side natural circulation circuit 8 is not limited to this, but here, water is used as the refrigerant. In addition, a blower fan 84 for sending air to the heat radiation side condenser 82 is disposed close to the heat radiation side condenser 82.

In the heat radiation side natural circulation circuit 8, the heat radiation side evaporator 81 takes heat from the high temperature part 72 of the Stirling refrigerator 7, and evaporates the refrigerant inside the heat radiation side evaporator 81. The evaporated refrigerant rises inside the heat radiation circuit 83 and is sent to the condenser 82 on the heat radiation side. When the heat flows to the outside of the Stirling cooler A when flowing through the condenser 82 on the radiating side, the phase changes to liquid by passing heat to the radiating side evaporator 81 of the radiating circuit 83. By repeating this operation, the temperature of the high-temperature part can be released to the outside.

[0052] In the above-described embodiment, the cooling chamber has a force exemplified by one provided inside the Stirling cooler. A plurality of cooling chambers may be provided instead of the one limited thereto. In this case, it is possible to widely use a cooling room such as a refrigerator room, a freezer room, a warm room, a cool room, etc., which cools to a temperature range in which a Stirling refrigerator can be generated.

Claims

The scope of the claims

[1] an inlet into which a liquid or substantially liquid refrigerant flows,

Heat exchange piping for evaporating the refrigerant,

An outlet through which the refrigerant flows out,

The evaporator, wherein the inflow port, the heat exchange pipe, and the outflow port are connected in this order, and at least a part of the heat exchange pipe branches into a plurality of parallel internal pipes.

[2] The evaporator according to claim 1, wherein the inflow port is disposed below the outflow port.

3. The evaporator according to claim 1, wherein the heat exchange pipe has an internal pipe branched in a horizontal direction.

[4] A loop type thermosiphon using the evaporator according to claim 3.

[5] A Stirling cooler for cooling the inside of the refrigerator with a Stirling refrigerator,

Using the loop-type thermosiphon according to claim 4 as a secondary refrigerant circulation circuit, and transporting cold generated in the Stirling refrigerator to the Stirling cooler using the secondary refrigerant circulation circuit. Stirling cooler characterized by.