JP2024013118A - Cooling system - Google Patents

Abstract

[Problem] To provide a cooling device capable of improving the heat exchange efficiency of a heat exchange section configured with a double pipe structure. [Solution] The cooling device includes a primary circuit 34 for forced circulation of a primary refrigerant by the operation of a compressor CM, a secondary circuit 44 for natural circulation of a secondary refrigerant, a heat exchange section HE for liquefying the secondary refrigerant by heat exchange between the primary refrigerant flowing through a primary refrigerant path 36 constituting the primary circuit 34 and the secondary refrigerant flowing through a secondary refrigerant path 46 constituting the secondary circuit 44, and a cooling section EP provided in the path of the secondary circuit 44 for vaporizing and cooling the secondary refrigerant, and the primary circuit 34 is disposed in an open space 20 in which air is permitted to flow. The heat exchange section is configured by inserting an inner pipe 104 forming the primary refrigerant path 36 into an outer pipe 102 forming the secondary refrigerant path 46 so that the primary refrigerant flowing through the inner pipe 104 flows through a position biased toward the upper side inside the outer pipe 102 forming the secondary refrigerant path 46. [Selected Figure] Fig. 3

Description

The present invention relates to a cooling device, and more specifically, a primary circuit that mechanically forcibly circulates a primary refrigerant, a secondary circuit that naturally circulates a secondary refrigerant, and a heat exchanger that exchanges heat between the primary refrigerant and the secondary refrigerant. The present invention relates to a cooling device comprising a section.

For example, a cooling device used in storage equipment such as a refrigerator or air conditioning equipment is equipped with a primary circuit that mechanically forces the primary refrigerant to circulate, and a secondary circuit that naturally circulates the secondary refrigerant. A thermosyphon that creates a temperature gradient in the secondary circuit by exchanging heat with the refrigerant, creating a density difference in the refrigerant, and transferring heat using natural convection that occurs under the action of gravity due to uneven density. There is a known heat transport mechanism called (see Patent Document 1, Patent Document 2, and Patent Document 3). The general configuration of such a cooling device is a compressor that compresses a gaseous primary refrigerant, a condenser that liquefies the compressed primary refrigerant, and a primary heat exchange section that is installed in a heat exchanger and that vaporizes the liquid primary refrigerant. A primary circuit is configured by connecting the two with piping, and a secondary heat exchange part that is provided in the heat exchanger and liquefies the gas phase secondary refrigerant, and a cooler that vaporizes the liquid phase secondary refrigerant. The secondary circuit is configured by connecting with separate piping, and the primary refrigerant and secondary refrigerant exchange heat in the heat exchanger, which ultimately cools the cooler in the secondary circuit. ing. Hydrocarbons (HC-based) such as butane and propane, or ammonia, which have excellent refrigerant properties such as heat of vaporization and saturation pressure, or ammonia are used as the primary refrigerant in such cooling systems. The refrigerant used is highly safe carbon dioxide, which is not toxic, flammable, or corrosive, and the use of natural refrigerants is intended to reduce environmental impact.

By the way, when using hydrocarbons, ammonia, etc. as the primary refrigerant, a compressor is not installed because the piping through which the refrigerant circulates may be damaged due to deterioration over time or some external factor, causing the primary refrigerant to leak. A heat exchanger through which primary refrigerant flows is arranged in the machine room. However, it is necessary to prevent the heat exchange efficiency from decreasing by, for example, surrounding the heat exchanger with a heat insulating material, which causes a decrease in workability during maintenance work and increases costs.

On the other hand, the cooling space where the cooler is placed can be improved by installing a gas sensor to detect leakage of primary refrigerant and a shutoff valve in the primary circuit to cut off the supply of primary refrigerant to the heat exchanger in the event of leakage of primary refrigerant. It also becomes possible to place a heat exchanger inside. However, the detection accuracy of the gas sensor is low, and there are drawbacks in that it reacts with leaked gases other than the primary refrigerant.Also, there is a risk that frost may adhere to the gas sensor and make detection impossible, so it is not recommended to place a heat exchanger in the cooling space. was actually difficult. Furthermore, it has been pointed out that it is difficult to reduce costs because it is necessary to use expensive gas sensors and shutoff valves.

In view of such problems, the applicant of the present application invented a configuration in which a heat exchange section is arranged in the cooling space so that the primary refrigerant path constituting the primary circuit is not exposed to the cooling space, and the applicant has proposed a structure in which a heat exchange section is disposed in the cooling space, and patent application No. 2022-17326 A patent has been applied for. In this patent application, by configuring the heat exchange part in a double pipe structure so that the piping forming the primary refrigerant path passes through the inside of the piping forming the secondary refrigerant path, the piping forming the primary refrigerant path Even if the primary refrigerant leaks, it is possible to keep the primary refrigerant inside the piping that constitutes the secondary refrigerant path.

Japanese Patent Application Publication No. 2002-48484 Japanese Patent Application Publication No. 2001-118134 Japanese Patent Application Publication No. 2010-7985

By the way, when the heat exchange part is configured so that the piping (inner pipe) through which the primary refrigerant flows is inserted through the inside of the piping (outer pipe) through which the secondary refrigerant flows, the primary refrigerant flowing through the inner pipe and the outer pipe The efficiency of heat exchange between the secondary refrigerant and the flowing secondary refrigerant greatly affects the cooling performance of the entire cooling system.

Therefore, the present invention has been proposed to suitably solve the above-mentioned problems, and an object of the present invention is to provide a cooling device that can improve the heat exchange efficiency of a heat exchange section configured with a double pipe structure. do.

In order to overcome the above problems and achieve the intended purpose, the first invention is as follows:
A primary circuit in which primary refrigerant is forcedly circulated by the operation of a compressor, a secondary circuit in which secondary refrigerant is naturally circulated, and a primary refrigerant flowing through a primary refrigerant path constituting the primary circuit and a secondary circuit constituting the secondary circuit. a heat exchange section that liquefies the secondary refrigerant by exchanging heat between the secondary refrigerants flowing through the secondary refrigerant path; and a cooling section that is provided in the path of the secondary circuit and evaporates and cools the secondary refrigerant. In the cooling device, the primary circuit is arranged in an open space where air circulation is allowed, and the cooling unit is arranged in a cooling space partitioned from the open space,
The heat exchange section is configured such that the first piping forming the primary refrigerant path is inserted through the second piping forming the secondary refrigerant path, and
The first pipe is arranged inside the second pipe so that the primary refrigerant flowing through the first pipe flows in a position biased upward in the second pipe. The gist is:
In this way, by configuring the first piping through which the primary refrigerant flows to be arranged at a position biased upward inside the second piping, the liquid-phase secondary refrigerant flowing through the second piping is It is possible to prevent the first pipe from being immersed (buried) and to expand the contact area between the gas phase secondary refrigerant and the first pipe. Therefore, the first pipe easily comes into contact with the gas phase secondary refrigerant flowing in the second pipe, improving the heat exchange efficiency in the heat exchange section, and reducing the liquid phase secondary refrigerant in the second pipe. Since the liquid-phase secondary refrigerant can be circulated well without the first pipe obstructing the flow of the secondary refrigerant, the cooling capacity can be improved.

The second invention is
The gist is that a support member is disposed below the first pipe, and the support member positions the first pipe upwardly within the second pipe.
In this way, by supporting the lower part of the first pipe with the support member, the first pipe can be satisfactorily positioned at a position biased upward inside the second pipe.

The third invention is
The gist is that a recess is provided in the upper part of the support member, and the recess is configured to support the first pipe.
In this way, by supporting the lower part of the first piping with the recess provided in the support member, the first piping can be stably supported by the support member, so that the first piping from the support member can be stably supported. It is possible to effectively prevent the first pipe from falling off, and to stably maintain the first pipe at a position biased toward the upper side inside the second pipe.

The fourth invention is
The support member is provided with a circulation space connected to the space inside the second pipe, and the secondary refrigerant flowing through the second pipe can flow through the circulation space of the support member. This is the summary.
By providing the circulation space in this way, the secondary refrigerant can be circulated well.

The fifth invention is
The gist is that the support member is formed by winding a wire into a coil shape.
By forming the support member into a coil shape in this way, the support member can be elastically deformed, so the support member can be placed in a position where the first pipe is biased upward inside the second pipe. The manufacturing process can be simplified by easily deforming the support member during pipe bending.

The sixth invention is
The supporting member formed in a coil shape is arranged such that the opening direction of the supporting member faces in the extending direction of the first pipe, and the supporting member is formed in a horizontally long flat shape. shall be.
By forming the support member into a horizontally long flat shape in this way, the stability of the first pipe supported by the support member can be increased.

The seventh invention is
The first pipe includes a protrusion that protrudes downward from the pipe main body through which the primary refrigerant flows, and the protrusion allows the pipe main body to be located upwardly within the second pipe. The gist is that it is structured.
In this manner, by providing the protrusion in the first pipe, the pipe main body through which the primary refrigerant flows can be positioned at an upwardly biased position inside the second pipe without providing a support member.

According to the cooling device according to the present invention, it is possible to improve the heat exchange efficiency of the heat exchange section configured in a double pipe structure.

1 is a side sectional view showing a refrigerator cooled by a cooling device according to Embodiment 1 of the present invention. FIG. 2 is a plan view showing a machine room in the refrigerator of Embodiment 1. FIG. FIG. 2 is a partially cutaway side view of the heat exchange section of Embodiment 1. FIG. 2 is a cross-sectional view of the double pipe section of the heat exchange section according to Embodiment 1, in which (a) is a cross-sectional view of the double pipe section in the radial direction, and (b) is a cross-sectional view of the double pipe section in the longitudinal direction. FIG. FIG. 2 is a cross-sectional view of a double pipe section of a heat exchange section according to Embodiment 2, and is a cross-sectional view of the double pipe section cut in the radial direction. FIG. 3 is a cross-sectional view and a schematic perspective view of a double pipe section of a heat exchange section according to Embodiment 3, in which (a) is a cross-sectional view of the double pipe section cut in the radial direction, and (b) is a sectional view of the double pipe section in Embodiment 3. FIG. 2 is a schematic perspective view showing a support member of FIG. FIG. 4 is a cross-sectional view of a double pipe section of a heat exchange section according to Embodiment 4, in which (a) is a cross-sectional view of the double pipe section taken in the radial direction, and (b) is a cross-sectional view of the double pipe section taken in the longitudinal direction. FIG. 3 is a partially cutaway side view showing a cross-sectional view taken in FIG. FIG. 7 is a cross-sectional view of a double pipe section of a heat exchange section according to Embodiment 5, and is a cross-sectional view of the double pipe section cut in the radial direction. FIG. 6 is a cross-sectional view of a double pipe portion of a heat exchange section according to Embodiment 6, in which (a) shows an example in which one protrusion is formed, and (b) shows an example in which two protrusions are formed. FIG. 7 is a cross-sectional view of a double pipe section of a heat exchange section according to a modification example, and is a cross-sectional view of the double pipe section cut in the radial direction.

Next, preferred embodiments of the cooling device according to the present invention will be described below with reference to the accompanying drawings. The description will be given by taking as an example a cooling device installed in a large refrigerator that is used for business purposes such as stores and can store a large amount of items such as vegetables and meat.

(Embodiment 1)
As shown in FIG. 1, the refrigerator 10 according to the first embodiment includes a box body 12 having an insulating structure that defines a storage chamber (closed space) 14 inside, and a metal panel 18 that is provided above the box body 12. The cabinet 16 constitutes an outer wall. The box body 12 is provided with an opening 12a that opens toward the front and serves as an entrance for loading and unloading articles, communicating with the storage chamber 14. Further, at the front of the box body 12, a heat insulating door 22 is rotatably arranged by a hinge (not shown), and by opening the heat insulating door 22, articles can be taken in and out of the storage chamber 14 through the opening 12a. At the same time, the storage chamber 14 can be hermetically sealed by closing the heat insulating door 22.

A machine room (open space) 20 is defined inside the cabinet 16 in which a part of a cooling device 32 for cooling the storage room 14 and a control device C for controlling the cooling device 32 are disposed. (See Figure 2). At the bottom of the machine room 20, a base plate 24 is installed, which is placed on the top plate 12b of the box body 12 and serves as a common board for devices installed in the machine room 20. The metal panel 18 forming the outer wall of the cabinet 16 is provided with air circulation holes (not shown) that communicate with the machine room 20 at appropriate locations. and are now interchanged. Note that the cabinet 16 is not provided with the metal panel 18 that serves as the ceiling of the refrigerator 10, and the upper part of the machine room 20 is open.

A cooling duct 26 is arranged at the upper part of the storage chamber 14 at a predetermined distance from the lower surface of the top plate 12b of the box body 12, and the cooling duct 26 and the opening 12c formed in the top plate 12b of the box body 12 are connected to each other. A cooling chamber (cooling space) 28 is defined between the base plate 24 and the base plate 24 facing the storage chamber 14 side via the base plate 24 . The cooling chamber 28 communicates with the storage chamber 14 through a suction port 26a formed at the front side of the bottom of the cooling duct 26 and a cold air outlet 26b formed at the rear side. It consists of A blower fan 30 is disposed at the suction port 26a, and by driving the blower fan 30, air from the storage chamber 14 is taken into the cooling chamber 28 through the suction port 26a, and cold air from the cooling chamber 28 is discharged from the cold air outlet 26b. It is sent to the storage chamber 14. The notch 12c of the top plate 12b is airtightly closed by the base plate 24, and the storage chamber 14 (cooling chamber 28) and the machine room 20 are separated by the base plate 24 and become mutually independent spaces. (See Figure 1).

As shown in FIG. 3, the cooling device 32 has two circuits: a mechanical compression type primary circuit 34 that forcedly circulates the refrigerant, and a secondary circuit (refrigerant circuit) 44 that consists of a thermosiphon where the refrigerant naturally convects. , a secondary loop refrigeration circuit connected (cascaded) to exchange heat via the heat exchange section HE is employed. The heat exchange section HE is provided with a primary refrigerant path 36 that constitutes a primary circuit 34, and a secondary refrigerant path 46 that is formed in a separate system from this primary refrigerant path 36 and that constitutes a secondary circuit 44. It is arranged in the cooling chamber 28 so as to be located on the lower surface side of the base plate 24 (see FIG. 3). That is, the primary circuit 34 and the secondary circuit 44 form independent refrigerant circulation paths capable of heat exchange, and in the heat exchange section HE, the primary refrigerant of the primary circuit 34 and the secondary refrigerant of the secondary circuit 44 are separated. Heat exchange takes place between them. Here, as the primary refrigerant circulating in the primary circuit 34, a hydrocarbon (HC) refrigerant such as butane or propane, or ammonia, which has excellent refrigerant properties such as heat of vaporization and saturation pressure, is used. . Further, as the secondary refrigerant circulating in the secondary circuit 44, highly safe carbon dioxide, which is not toxic, flammable, or corrosive, is preferably employed.

The primary circuit 34 includes a compressor CM that compresses gas phase primary refrigerant, a condenser CD that liquefies the compressed primary refrigerant, an expansion valve EV as a pressure reducing means that reduces the pressure of the liquid phase primary refrigerant, and a liquid phase primary refrigerant. It is configured by connecting the primary refrigerant path 36 of the heat exchange unit HE that vaporizes the primary refrigerant with a refrigerant pipe 38 (see FIG. 3). Here, the compressor CM is continuously driven during the cooling operation of the cooling device 32, and is stopped when the cooling device 32 is stopped. The compressor CM and the condenser CD are commonly disposed on the base plate 24 in the machine room 20, and the condenser fan FM that forcibly cools the condenser CD is also disposed on the base plate 24 opposite to the condenser CD. It is located in Here, the condenser CD is arranged on the front side of the machine room 20 in close proximity to the metal panel (front panel) 18 forming the front surface of the cabinet 16, and the condenser fan FM is arranged on the rear side of the condenser CD. . Moreover, the compressor CM is arranged behind the condenser fan FM (see FIG. 2). In this way, in the machine room 20, the condenser CD, condenser fan FM, and compressor CM are arranged in a straight line along the flow direction of the air sent out by the condenser fan (air blowing means) FM in the machine room 20. will be placed. That is, by driving the condenser fan FM, outside air is taken into the machine room 20 through an air circulation hole (not shown) provided between the front panel 18 and the cabinet 16, and this outside air is drawn from the front side of the machine room 20 to the rear side. It flows to the side and exchanges heat with the condenser CD and compressor CM.

In the primary circuit 34, the primary refrigerant is compressed by the compressor CM, so that the primary refrigerant is forcedly circulated in the order of the compressor CM, the condenser CD, the expansion valve EV, the primary refrigerant path 36 of the heat exchanger HE, and the compressor CM. , the required cooling is performed in the primary refrigerant path 36 under the action of each device (see FIG. 3). Note that the above-mentioned control device C is disposed on the base plate 24 in the machine room 20 at a position (on the side of the machine room 20) where the air flow by the condenser fan FM is not obstructed.

The secondary circuit 44 includes a secondary refrigerant path 46 of the heat exchanger HE that liquefies the gas phase secondary refrigerant (vaporized refrigerant), and an evaporator EP that evaporates the liquid phase secondary refrigerant (liquefied refrigerant). (See Figure 3). Further, the secondary circuit 44 is configured to connect the secondary refrigerant path 46 and the evaporator EP via a liquid pipe 48 and a gas pipe 50, and is configured to connect the secondary refrigerant path 46 to the liquid pipe 48 to reduce gravity. Under the action, the liquid phase secondary refrigerant is supplied to the evaporator EP, and the gaseous phase secondary refrigerant is refluxed from the evaporator EP to the secondary refrigerant path 46 via the gas pipe 50. That is, the liquid piping 48 forms an introduction path for introducing the liquid phase secondary refrigerant from the heat exchange section HE to the evaporator EP, and the gas piping 50 forms an introduction path for introducing the liquid phase secondary refrigerant from the evaporator EP to the heat exchange section HE. It forms a circulation path for circulation. Thus, in this embodiment, the liquid pipe 48 and the gas pipe 50 are formed as continuous pipes with the evaporation pipe 52 forming the evaporator EP. Here, the evaporator EP is disposed in the cooling chamber 28 located below the machine room 20 so as to be located below the heat exchange section HE, and is connected to the liquid phase from the secondary refrigerant path 46 of the heat exchange section HE. The secondary refrigerant is allowed to flow down under the action of gravity.

The evaporator EP includes an evaporation pipe 52 having a meandering pipe line, and fins 53 provided on the evaporation pipe 52. The inflow end of the evaporation pipe 52 connected to the lower end of the liquid pipe 48 is arranged at the lower part of the evaporator EP, and the outflow end of the evaporation pipe 52 connected to the lower end of the gas pipe 50 is arranged at the upper part of the evaporator EP. The evaporation pipe 52 is arranged such that the inflow end of the evaporation pipe 52 is located below the outflow end (see FIG. 3). Further, the pipe line of the evaporator tube 52 extends between the upper and lower positions of the inflow end and the outflow end, and allows the liquid phase secondary refrigerant that has flowed into the evaporation tube 52 to be subjected to the action of evaporation of the liquid phase secondary refrigerant. It is designed so that it is diffused along the pipe to the outflow end.

Next, the heat exchange section HE of Embodiment 1 will be specifically explained. As shown in FIGS. 3 and 4, the heat exchange section HE includes an outer tube 102 and a double tube section 100 into which an inner tube 104 is inserted with a space left inside the outer tube 102. The primary refrigerant flows through the space inside the inner tube 104, and the secondary refrigerant flows through the space between the outer tube 102 and the inner tube 104. That is, a primary refrigerant path 36 is formed inside the inner tube 104, and a secondary refrigerant path 46 is formed between the outer tube 102 and the inner tube 104. Note that the outer tube 102 and the inner tube 104 are made of a metal material with excellent thermal conductivity.

Here, the double pipe section 100 of the heat exchange section HE is formed such that the pipe path meanders, and both ends of the double pipe section 100 are connected to the base plate 20 so as to extend from the cooling chamber 28 to the machine room 20. It is configured to penetrate through and be exposed to the machine room 20 (see FIG. 3). Here, at both ends of the double pipe section 100 penetrating into the machine room 20 side, an inner pipe 104 extends from the end of the outer pipe 102, and one of the inner pipes 104 extending from the outer pipe 102 has a The refrigerant pipe 38 on the inflow side that connects to the expansion valve EV is connected, and the refrigerant pipe 38 on the outflow side that connects to the compressor CM is connected to the other side of the inner pipe 104 extending from the outer pipe 102. A circuit 34 is formed.

Further, in the double pipe section 100 of the heat exchange section HE, connection pipes 108 extending toward the evaporator EP located below the heat exchange section HE are provided at two locations so as to communicate with the secondary refrigerant path 46. The upper end of a liquid pipe 48 provided in the evaporator EP is connected to one connecting pipe 108, and the upper end of a gas pipe 50 provided in the evaporator EP is connected to one connecting pipe 108. , forming a secondary circuit 44.

Here, as shown in FIG. 3, the inner pipe 104 of the heat exchange section HE and the refrigerant pipe 38 forming the primary circuit 34 are connected so that the connection part 106 is located in the machine room 20. The inner pipe 104 and the refrigerant pipe 38 may be connected by welding or by using a joint or the like. In this first embodiment, the inner pipe 104 and the refrigerant pipe 38 are connected by welding at the connection portion 106.

Further, the pipe line of the double pipe section 100 of the heat exchange section HE is inclined downward from the connection side with the gas pipe 50 toward the connection side of the liquid pipe 48, and is cooled in the heat exchange section HE. The liquid-phase secondary refrigerant that has been liquefied naturally flows toward the liquid pipe 48 due to its own weight. Further, the heat exchange section HE is configured such that the flow direction of the secondary refrigerant flowing through the secondary refrigerant path 46 and the flow direction of the primary refrigerant flowing through the primary refrigerant path 36 are opposite flows.

As shown in FIG. 3, in the heat exchange section HE, a double pipe section 100 located in the cooling chamber 28 is covered with a heat insulating material 110, and the cooling chamber 28 is closed due to the vaporization of the secondary refrigerant in the evaporator EP. By cooling the secondary refrigerant flowing through the heat exchange section HE, the secondary refrigerant is cooled so as not to liquefy. Here, the heat insulating material 110 is not particularly limited, and conventionally known heat insulating materials such as polyurethane foam can be used.

Here, the double pipe section 100 of the heat exchange section HE will be explained in more detail. As shown in FIGS. 3 and 4, the inner tube 104 forming the double tube section 100 is configured such that the primary refrigerant flowing through the inner tube 104 flows through a position biased upward inside the outer tube 102. It is arranged inside the outer tube 102 and is configured so that the inner tube 104 easily comes into contact with the gas phase secondary refrigerant flowing through the outer tube 102 . Specifically, in this first embodiment, as shown in FIG. 4, a support member 112 is arranged between the inner tube 104 and the outer tube 102 so as to be located below the inner tube 104, The member 112 allows the inner tube 104 to be positioned upwardly inside the outer tube 102. Here, the support member 112 can be formed of a metal material or a synthetic resin material, and may also be formed into a rod shape such as a round bar or a square bar, or a pipe shape such as a cylindrical shape or a square tube shape. It may be formed as follows. In this first embodiment, the support member 112 is formed into a round bar shape, and is attached so that the central axis of the support member 112 faces in the direction in which the inner tube 104 extends.

Further, as shown in FIG. 4(b), the support members 112 are provided at a plurality of locations spaced apart in the extending direction of the double tube section 100 (outer tube 102, inner tube 104). In this case, the entire inner tube 104 is positioned upwardly inside the outer tube 102 . Here, in the double pipe section 100 where the pipe line is bent in a meandering manner, it is more preferable to arrange the support member 112 in the pipe line part that extends linearly. By preventing the support member 112 from being located in the bent portion of the double pipe portion 100, it is possible to prevent the support member 112 from obstructing the flow of the secondary refrigerant within the outer pipe 102. Further, the support member 112 is preferably formed so that the area occupied by the space between the outer tube 102 and the inner tube 104 is small in a cross section across the double tube section 100.

In addition, the double tube section 100 is constructed by joining the support member 112 to the outer circumferential surface of the inner tube 104 by welding or adhesive, and then inserting the inner tube 104 to which the support member 112 has been joined into the outer tube 102. It is formed by bending as appropriate. In this way, by bending the inner tube 104 to which the support member 112 has been joined after inserting it into the outer tube 102, the support member 112 can be positioned at a predetermined position within the outer tube 102 without the support member 112 being displaced. Thus, the inner tube 104 can be held in an upwardly biased position inside the outer tube 102.

(Effect of Embodiment 1)
Next, the operation of the cooling device 32 according to the first embodiment will be explained. In the cooling device 32, when the cooling operation is started, the circulation of the refrigerant is started in each of the primary circuit 34 and the secondary circuit 44. First, the primary circuit 34 will be explained. The compressor CM and the condenser fan FM are driven, the gas phase primary refrigerant is compressed by the compressor CM, and this primary refrigerant is supplied to the condenser CD via the refrigerant pipe 38. Then, it is condensed and liquefied by forced cooling by the condenser fan FM, thereby making it into a liquid phase. The liquid phase primary refrigerant is depressurized by the expansion valve EV, and in the primary refrigerant path 36 of the heat exchanger HE takes heat from the secondary refrigerant flowing through the secondary refrigerant path 46 (endotherm) and expands and vaporizes all at once. In this way, the primary circuit 34 functions to forcibly cool the secondary refrigerant path 46 using the primary refrigerant path 36 in the heat exchange section HE. The gas phase primary refrigerant vaporized in the primary refrigerant path 36 then returns to the compressor CM via the refrigerant pipe 38, repeating a forced circulation cycle.

In the secondary circuit 44, since the secondary refrigerant path 46 is cooled by the primary refrigerant path 36, the gas phase secondary refrigerant radiates heat and condenses in the secondary refrigerant path 46, changing its state from the gas phase to the liquid phase. As a result, the specific gravity increases, so that the liquid phase secondary refrigerant flows down along the secondary refrigerant path 46 under the action of gravity. In the secondary circuit 44, the evaporator EP is disposed below the heat exchange section HE including the secondary refrigerant path 46, thereby providing a head between the secondary refrigerant path 46 and the evaporator EP. That is, the liquid-phase secondary refrigerant can be caused to naturally flow down under the action of gravity toward the evaporator EP via the liquid pipe 48 connected to the lower part of the secondary refrigerant path 46. In the process of flowing through the evaporation pipe 52 of the evaporator EP, the liquid-phase secondary refrigerant absorbs heat from the surrounding atmosphere of the evaporator EP, evaporates, and transitions to a gas phase. The gas phase secondary refrigerant is returned from the evaporator EP to the secondary refrigerant path 46 via the gas pipe 50, and the secondary refrigerant is circulated in the secondary circuit 44 with a simple configuration without using power such as a pump or a motor. The natural cycle repeats.

By blowing the air in the storage chamber 14 sucked into the cooling chamber 28 from the suction port 26a by the blower fan 30 onto the cooled evaporator EP, the air exchanged heat with the evaporator EP becomes cold air. The storage chamber 14 is cooled by sending the cold air from the cooling chamber 28 to the storage chamber 14 via the cold air outlet 26b. The cold air circulates inside the storage chamber 14 and returns to the cooling chamber 28 via the suction port 26a, repeating the cycle.

Here, in the cooling device 32 of the first embodiment, the heat exchange section HE is arranged in the cooling chamber 28 so that the primary refrigerant path 36 constituting the primary circuit 34 is not exposed to the cooling chamber 28 . Therefore, the primary refrigerant flowing through the primary refrigerant path 36 can be effectively prevented from leaking into the cooling chamber 28, and carbonization of butane, propane, etc., which have excellent refrigerant properties such as heat of vaporization and saturation pressure, can be effectively prevented. The heat exchange section HE can be arranged in the cooling chamber 28 while using hydrogen-based (HC-based) or ammonia, which is known to be toxic, as the primary refrigerant.

In particular, as in this embodiment, the heat exchanger HE is configured to include an outer tube 102 and a double tube section 100 into which the inner tube 104 is inserted with a space left inside the outer tube 102, As the primary refrigerant flows through the space inside the inner pipe 104 and the secondary refrigerant flows through the space between the outer pipe 102 and the inner pipe 104, corrosion etc. occur, causing holes in the inner pipe 104. Even if an eclipse occurs, the primary refrigerant leaking from the inner pipe 104 can remain inside the outer pipe 102, and the primary refrigerant can be effectively prevented from directly leaking into the cooling chamber 28. In addition, by covering the double pipe section 100 located in the cooling chamber 28 in the heat exchange section HE with the heat insulating material 110, the cooling chamber for the refrigerant (primary refrigerant and secondary refrigerant) flowing through the heat exchange section HE is provided. Leakage to 28 can be suppressed. That is, it is possible to realize the cooling device 32 that meets higher safety standards.

Further, in the double pipe section 100, the inner pipe 104 through which the primary refrigerant flows is arranged at a position biased upward inside the outer pipe 102. Therefore, the inner tube 104 is prevented from being immersed (buried) in the liquid phase secondary refrigerant flowing through the outer tube 102, and the contact area between the gaseous phase secondary refrigerant and the inner tube 104 can be expanded. Here, if the inner tube 104 is located so as to be immersed in the liquid-phase secondary refrigerant, the heat exchange area between the gas-phase secondary refrigerant and the inner tube 104 becomes small, leading to a decrease in heat exchange efficiency, and This leads to the inner pipe 104 obstructing the flow of the liquid-phase secondary refrigerant, resulting in a decrease in cooling capacity. On the other hand, by arranging the inner tube 104 at a position biased upward inside the outer tube 102, the inner tube 104 can easily come into contact with the gas-phase secondary refrigerant flowing inside the outer tube 102, and heat Since the heat exchange efficiency in the exchange section HE can be improved and the liquid phase secondary refrigerant can be circulated well without the inner tube 104 inhibiting the flow of the liquid phase secondary refrigerant in the outer tube 102, This leads to increased cooling capacity.

Moreover, by supporting the lower part of the inner tube 104 with the support member 112, the inner tube 104 can be satisfactorily positioned at a position biased upward inside the outer tube 102. By preventing the support member 112 from being located at the bent portion of the double pipe portion 100, the support member 112 is prevented from interfering with the flow of the secondary refrigerant at the bent portion where the flow of refrigerant tends to decrease. , the heat exchange efficiency can be increased by positioning the inner tube 104 toward the upper side inside the outer tube 102.

(Embodiment 2)
Next, a cooling device according to a second embodiment will be described. However, since the cooling device according to the second embodiment has basically the same configuration as the cooling device 32 described in the first embodiment, and the shape of the support member is different, the components and configurations having the same functions are different from each other. The same reference numerals are used to omit detailed explanation.

As shown in FIG. 5, the support member 114 of the cooling device 32 of the second embodiment is provided with a recess 114a in the upper part of the support member 114, so that the lower part of the inner tube 104 is supported by the recess 114a. It is configured. Specifically, like the support member 112 of Embodiment 1, the support member 114 of Embodiment 2 is formed into a round bar shape from a metal material or a synthetic resin material, and has a center portion on the upper side of the support member 114. A V-shaped recess 114a is formed to extend in the axial direction, and two surfaces 114b forming the recess 114a are in contact with the outer peripheral surface of the inner tube 104. Note that the surface 114b forming the recessed portion 114a may be formed in a bent shape so that the outer circumferential surface of the inner tube 104 contacts the recessed portion 114a at three or more points. The support member 114 of the second embodiment can be molded by extrusion molding, injection molding, or other conventionally known methods.

(Effects of Embodiment 2)
In this way, by supporting the lower part of the inner tube 104 with the recess 114a provided in the support member 114, the inner tube 104 can be stably supported by the support member 114. Therefore, the inner tube 104 can be effectively prevented from falling off from the support member 114, and the inner tube 104 can be stably maintained at a position biased toward the upper side inside the outer tube 102. In particular, by configuring the two surfaces 114b forming the recess 114a to be in contact with the outer peripheral surface of the inner tube 104, the stability of the inner tube 104 can be further enhanced.

(Embodiment 3)
Next, a cooling device according to Embodiment 3 will be described. However, the cooling device according to Embodiment 3 has basically the same configuration as the cooling device 32 described in Embodiment 1, but the shape of the support member is different, so the members and configurations having the same functions are different from each other. The same reference numerals are used to omit detailed explanation.

As shown in FIG. 6, the support member 116 of the cooling device 32 of the third embodiment is formed to have a circulation space 116a connected to the inside of the outer tube 102, so that the secondary refrigerant flowing through the inner tube 104 can flow through the support member 116. It is configured to be able to flow through the circulation space 116a of the member 116. More specifically, as shown in FIG. 6(b), the support member 116 of the third embodiment is formed of a wire rod 116b such as a steel wire in a mesh shape. A continuous circulation space 116a is formed inside 116. Note that the support member 116 may be formed by joining wire rods arranged in a lattice shape by welding, adhesion, or the like, or may be formed by weaving wires or the like.

(Effects of Embodiment 3)
In this way, by providing the circulation space 116a that connects the inside and outside of the support member 116, the secondary refrigerant flowing inside the outer tube 102 can flow inside the support member 116. Therefore, even when the support member 116 is disposed inside the outer tube 102, a secondary refrigerant circulation area can be secured and the secondary refrigerant can be circulated satisfactorily. Thereby, the inner tube 104 can be positioned upwardly inside the outer tube 102 without obstructing the flow of the secondary refrigerant with the support member 116, thereby improving the heat exchange efficiency of the heat exchange section HE.

(Embodiment 4)
Next, a cooling device according to Embodiment 4 will be described. However, the cooling device according to Embodiment 4 has basically the same configuration as the cooling device 32 described in Embodiment 1, but the shape of the support member is different, so the members and configurations having the same functions are different from each other. The same reference numerals are used to omit detailed explanation.

The support member 118 of the cooling device 32 of the fourth embodiment is formed by winding a wire into a coil shape, as shown in FIGS. 7(a) and 7(b). That is, the support member 118 of Embodiment 4 is formed in a compression spring shape, and the support member 118 formed in a coil shape is arranged so that its opening direction faces in the extending direction of the inner tube 104. There is. As described above, the support member 118 of the fourth embodiment, like the support member 116 of the third embodiment, is formed to have a circulation space 118a that is connected to the inside of the outer tube 102, and has a secondary The refrigerant can flow through the circulation space 118a of the support member 118.

(Effects of Embodiment 4)
By forming the support member 118 by winding the wire into a coil in this way, the support member 118 can be elastically deformed. As a result, when the inner tube 104 to which the supporting member 118 is joined is bent after being inserted into the outer tube 102, the supporting member 118 is elastically deformed, and the inner tube 104 is moved upwardly inside the outer tube 102. The double tube section 100 can be easily bent while being positioned at a side-biased position using the support member 118, and the manufacturing of the heat exchange section HE can be simplified. By forming the support member 118 into a coil shape in this manner, it becomes possible to easily bend the double pipe portion 100 into a desired shape even with the support member 118 interposed therebetween.

Furthermore, by forming the support member 118 into a coil shape and providing a circulation space 118a that connects the inside and outside of the support member 118, the secondary refrigerant flowing inside the outer tube 102 can flow inside the support member 118. become able to. Therefore, as in the third embodiment, even when the support member 118 is disposed within the outer tube 102, there is an advantage that a flow area for the secondary refrigerant can be secured and the secondary refrigerant can be circulated satisfactorily.

(Embodiment 5)
Next, a cooling device according to Embodiment 5 will be described. However, the cooling device according to Embodiment 5 has basically the same configuration as the cooling device 32 described in Embodiment 1, but the shape of the support member is different, so the members and configurations having the same functions are different from each other. The same reference numerals are used to omit detailed explanation.

The support member 120 of the cooling device 32 of the fifth embodiment is formed by winding a wire into a coil shape as in the fourth embodiment, and the support member 120 formed in the coil shape extends in the extending direction of the inner tube 104. It is arranged so that the opening direction is facing. That is, like the support member 118 of Embodiment 4, the support member 120 of the fifth embodiment is formed to have a circulation space 120a connected to the inside of the outer tube 102, so that the secondary refrigerant flowing through the inner tube 104 can It is possible to circulate through the circulation space 120a of the support member 120.

Here, as shown in FIG. 8, the support member 120 of the fifth embodiment is arranged inside the outer tube 102 and is formed in a horizontally long flat shape. The support member 120 is provided with a recess 120b on the upper side, and is configured to support the lower part of the inner tube 104 with the recess 120b. Specifically, the support member 120 of Embodiment 5 is formed into a horizontally oblong elliptical flattened coil shape and then deformed so as to crush the upper side of the support member 120 to form the recessed portion 120b. .

(Effects of Embodiment 5)
In this way, by forming the support member 120 by winding the wire into a coil shape, the support member 120 can be elastically deformed as in the fourth embodiment. Thereby, when the inner tube 104 to which the supporting member 120 is joined is inserted into the outer tube 102 and then bent, the supporting member 120 is elastically deformed, so that the bending can be easily performed. By forming the support member 120 into a coil shape in this manner, it becomes possible to easily bend the double pipe portion 100 into a desired shape even with the support member 120 interposed therebetween.

Further, by forming the support member 120 in a horizontally long flat shape, the inner tube 104 can be stably supported by the support member 120. Furthermore, as in the second embodiment, by supporting the lower part of the inner tube 104 with the recess 120b provided in the support member 120, the inner tube 104 can be stably supported by the support member 120. Therefore, the inner tube 104 can be effectively prevented from falling off from the support member 120, and the inner tube 104 can be stably maintained at a position biased toward the upper side inside the outer tube 102.

Furthermore, by forming the support member 120 into a coil shape and providing a circulation space 120a that connects the inside and outside of the support member 118, the secondary refrigerant flowing inside the outer tube 102 can flow inside the support member 118. become able to. Therefore, as in Embodiment 4, even when the support member 120 is disposed within the outer tube 102, there is an advantage in that a secondary refrigerant circulation area can be ensured and the secondary refrigerant can circulate favorably.

(Embodiment 6)
Next, a cooling device according to Embodiment 6 will be described. Here, in the cooling device according to Embodiments 1 to 5, the support members 112, 114, 116, 118 are arranged so as to be located below the inner pipe 104, and the support members 112, 114, 116, 118 support the inner pipe. 104 is arranged so as to be biased toward the upper part of the inside of the outer tube 102, but in this sixth embodiment, the shape of the inner tube 124 allows the flow to flow through the inner tube 124 without providing support members 112, 114, 116, 118. The primary refrigerant is configured to flow inside the outer tube 102 at a position biased toward the upper side. The cooling device according to Embodiment 6 has basically the same configuration as the cooling device 32 described in Embodiment 1 except for the shape of the inner tube, and the same reference numerals are given to the members and configurations having the same functions. The detailed explanation will be omitted.

As shown in FIGS. 9(a) and 9(b), the inner tube 124 of the double tube section 100 of the sixth embodiment includes a tube body section 126 through which the primary refrigerant flows, and a tube body section 126 that protrudes downward from the tube body section 126. A protrusion 128 is provided. Then, with the inner tube 124 inserted into the outer tube 102, the protrusion 128 of the inner tube 124 contacts the inner surface of the outer tube 102, and the protrusion 128 causes the tube body 126 to move upward inside the outer tube 102. It is located off to the side. Here, this inner tube 124 can be molded by a conventionally known molding method such as extrusion molding. Alternatively, a space may be formed inside the protrusion 128 so that the primary refrigerant flows inside the protrusion 128. It is preferable to make the space inside the protrusion 128 as narrow as possible. Further, the number of protrusions 128 that protrude from the tube body 126 is not particularly limited, and one protrusion 128 may be provided as shown in FIG. 9(a), or A plurality of protrusions 128 may be provided as shown in (b).

(Effect of Embodiment 6)
By providing the protrusion 128 on the inner tube 124 in this way, the tube body 126 through which the primary refrigerant mainly flows in the inner tube 124 is placed in an upwardly biased position inside the outer tube 102. It can be well positioned. As a result, as in Embodiment 1, etc., the tube main body portion 126 of the inner tube 104 easily comes into contact with the gas phase secondary refrigerant flowing inside the outer tube 102, improving the heat exchange efficiency in the heat exchange section HE. At the same time, the flow of the liquid phase secondary refrigerant in the outer tube 102 can be well circulated without the inner tube 124 inhibiting the flow of the liquid phase secondary refrigerant, which leads to an increase in the cooling capacity. Furthermore, without providing the support members 112, 114, 116, 118 as in the first to fifth embodiments, the primary refrigerant flowing in the inner pipe 124 can be allowed to flow in a position biased upward in the outer pipe 102. Therefore, it is possible to reduce costs by reducing the number of parts and processing man-hours.

(Example of change)
The cooling device according to the present invention is not limited to that shown in the embodiments described above, and various modifications can be made.

(1) Although the double pipe section 100 of the heat exchange section HE located in the cooling chamber 28 is covered with the heat insulating material 110, the heat insulating material 110 may be omitted.
(2) The outer tube 102 is not limited to having a circular cross section; for example, as shown in FIG. 10, the outer tube 102 may have a vertically elongated elliptical cross section. By making the cross section of the outer tube 102 into a vertically elongated oval shape, it is possible to restrict the movement of the inner tube 104 inserted inside in the width direction, so that the inner tube 104 can be moved away from the support member 112 (114, 116, 118). In addition to being able to effectively prevent it from falling off, the inner tube 104 is unevenly located at the upper side of the outer tube 102, so that the space through which the liquid-phase secondary refrigerant flows (the space below the inner tube 104) can be further expanded. It can be widely secured. Note that the cross-sectional shape of the outer tube 102 is not limited to a vertically long elliptical shape, but may also be a vertically long rectangular shape.
(3) Although the case where the cooling device 32 is employed in the refrigerator 10 has been described as an example, it is also applicable to so-called storages such as freezers, freezers/refrigerators, showcases and prefabricated warehouses, and other air conditioning equipment.
(4) Although the expansion valve EV was used as a pressure reducing means for the primary circuit 34, a capillary tube or other means may be used.

20 Machine room (open space), 28 Cooling room (cooling space) 34 Primary circuit, 36 Primary refrigerant path, 44 Secondary circuit, 102 Outer pipe (piping forming the secondary refrigerant path)
104 Inner pipe (piping constituting the primary refrigerant path), 114, 116, 118, 120 Support member 124 Inner pipe (piping constituting the primary refrigerant path), 126 Pipe main body, 128 Projection part

Claims (7)

A primary circuit in which primary refrigerant is forcedly circulated by the operation of a compressor, a secondary circuit in which secondary refrigerant is naturally circulated, a primary refrigerant flowing through a primary refrigerant path constituting the primary circuit, and a secondary circuit constituting the secondary circuit. a heat exchange section that liquefies the secondary refrigerant by exchanging heat between the secondary refrigerants flowing through the secondary refrigerant path; and a cooling section that is provided in the path of the secondary circuit and evaporates and cools the secondary refrigerant. In a cooling device, the primary circuit is arranged in an open space where air circulation is allowed, and the cooling unit is arranged in a cooling space partitioned from the open space,
The heat exchange section is configured such that the first piping forming the primary refrigerant path is inserted through the second piping forming the secondary refrigerant path, and
The first pipe is arranged inside the second pipe so that the primary refrigerant flowing through the first pipe flows in an upwardly biased position inside the second pipe. A cooling device featuring: A support member is disposed below the first pipe, and the support member positions the first pipe upwardly within the second pipe. Item 1. Cooling device according to item 1. 3. The cooling device according to claim 2, wherein a recess is provided in an upper part of the support member, and the recess supports the first pipe. The support member is provided with a circulation space connected to the space inside the second pipe, and the secondary refrigerant flowing through the second pipe can flow through the circulation space of the support member. The cooling device according to claim 2 or 3, characterized in that: 3. The cooling device according to claim 2, wherein the support member is formed by winding a wire into a coil. The supporting member formed in a coil shape is arranged such that the opening direction of the supporting member faces in the extending direction of the first pipe, and the supporting member is formed in a horizontally long flat shape. The cooling device according to claim 5. The first pipe includes a protrusion that protrudes downward from the pipe main body through which the primary refrigerant flows, and the protrusion allows the pipe main body to be located upwardly within the second pipe. The cooling device according to claim 1, characterized in that:

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