TWI440806B - Cooling unit and method of making the same - Google Patents

Description

Cooling device and method of manufacturing same

The present invention relates to a cooling device, and more particularly to a primary circuit that mechanically forcibly circulates a primary refrigerant, a secondary circuit that naturally circulates secondary refrigerant, and a primary heat exchange unit and two A cooling device for a heat exchange heat exchange unit of the secondary heat exchange unit.

There is a cooling device including a primary circuit that mechanically forcibly circulates a primary refrigerant and a secondary circuit that naturally circulates the secondary refrigerant, and exchanges heat between the primary refrigerant and the secondary refrigerant (see, for example, Japan). JP-A-2002-48484). As shown in Fig. 16, the primary circuit 94 of the cooling device 90 is connected by a pipe 98: a compressor CM that compresses the primary vapor phase refrigerant, a condenser CD that liquefies the compressed primary refrigerant, and a liquid phase. The expansion valve EV in which the pressure of the primary refrigerant is lowered and the primary heat exchange unit 96 provided in the plate heat exchanger 110 for vaporizing the liquid primary refrigerant are connected, and the secondary circuit 104 is connected by another pipe 108: The plate heat exchanger 110 is configured to include a secondary heat exchange unit 106 that liquefies the gas phase secondary refrigerant, and an evaporator EP that vaporizes the liquid secondary refrigerant, and is configured in the plate heat exchanger 110. The primary refrigerant and the secondary refrigerant are subjected to heat exchange, and finally the evaporator EP of the secondary circuit 104 is cooled. In the refrigerating machine including such a cooling device 90, the constituent components CM, CD, EV, and plate heat exchanger 110 of the primary circuit 94 are disposed in an open space exposed to the outside air, and will constitute the secondary circuit 104. The evaporator EP is disposed in an enclosed space partitioned by the bottom plate 112 below the open space to thereby cool the enclosed space.

In the cooling device 90 including the above-described natural circulation type refrigeration circuit (secondary circuit 104), the liquid secondary refrigerant condensed in the plate heat exchanger 110 is naturally flown downward by the gravity toward the evaporator EP, thereby determining the second time. The circulation direction of the refrigerant. Therefore, in the above-described cooling device 90, the plate heat exchanger 110 is placed in an upright state (the posture in which the overlapping direction of the plate is horizontal) so that the secondary refrigerant can naturally flow down in the fixed direction, and in the plate type An inlet of the vapor-phase secondary refrigerant is provided on the upper end side of the heat exchanger 110, and an outlet of the liquid-phase secondary refrigerant is provided on the lower end side of the plate heat exchanger 110. On the other hand, in order to increase the heat exchange efficiency between the primary refrigerant and the secondary refrigerant in the plate heat exchanger 110, the flow direction of the primary refrigerant and the secondary refrigerant is reversed. In the cooling device 90, an inflow port for the primary refrigerant inflow on the primary circuit 94 side is provided on the lower end side of the plate heat exchanger 110, and a primary refrigerant outlet is formed on the upper end side of the plate heat exchanger 110. In the primary circuit 94, the primary refrigerant flows through the plate heat exchanger 110 against gravity. Here, in order to achieve an improvement in heat exchange efficiency between the primary refrigerant and the secondary refrigerant in the plate heat exchanger 110, in order to effectively use the heat transfer area of the primary refrigerant in the path of the primary heat exchange unit 96, the primary heat exchange is performed. The path of the portion 96 is preferably filled with a refrigerant once. In the conventional cooling device 90, since the primary refrigerant is circulated against the gravity in the plate heat exchanger 110, the density of the refrigerant increases during the rise of the primary refrigerant and the retention in the path of the primary heat exchange unit 96 occurs. The increase in the amount of refrigerant leads to an increase in the amount of refrigerant used, and has the disadvantage of an increase in cost.

Further, in a machine in which a storage chamber (corresponding to the above-described closed space) is partitioned inside, such as a refrigerator, it is highly desirable to increase the volume of the storage chamber without changing the size of the device itself. However, as described above, in the secondary circuit 104, based on the difference in height between the inflow port and the outflow port of the secondary refrigerant using the plate heat exchanger 110, the relationship of the circulation direction of the secondary refrigerant is determined, so the plate type heat exchanger 110 It is placed on the bottom plate 112 in an upright state, which is a factor that presses the volume of the storage chamber located below the bottom plate 112.

Accordingly, it is an object of the present invention to provide a compact type cooling device which can reduce the amount of primary refrigerant used without reducing the heat exchange efficiency of the heat exchanger, and can suppress the height dimension of the heat exchanger. Its manufacturing method.

In order to overcome the above problems and achieve the desired object, the cooling device of the present invention includes a primary circuit that mechanically forcibly circulates the primary refrigerant, a secondary circuit that naturally circulates the secondary refrigerant, and primary refrigerant and secondary refrigerant. A heat exchanger for performing heat exchange between the first and second circuits includes: a compressor that compresses a primary refrigerant, and a condenser that condenses a primary refrigerant compressed by the compressor, and the condenser is used by the condenser a decompressing device for depressurizing the condensed primary refrigerant, and a primary heat exchange portion formed in the heat exchanger to evaporate the primary refrigerant condensed by the condenser; and connecting the condenser to the primary heat exchange via the pressure reducing device The primary liquid pipe is connected to one end side of the heat exchanger, and the primary gas pipe connecting the compressor and the primary heat exchange unit is connected to the other end side of the heat exchanger. The secondary circuit system includes: a secondary heat exchange unit formed in the heat exchanger to condense the secondary refrigerant, and a second heat exchanger to be condensed by the secondary heat exchange unit An evaporator that evaporates the refrigerant, and connects a secondary liquid pipe connected to the secondary heat exchange unit and the evaporator to a connection end side of the primary liquid pipe in the heat exchanger, and is connected to the secondary heat exchange unit The secondary gas pipe of the evaporator is connected to the connection end side of the primary gas pipe in the heat exchanger, and the open space of the primary circuit is disposed by the heat insulating wall portion, and the above-mentioned primary circuit is disposed In the closed space of the evaporator of the secondary circuit, the heat exchanger is inclined in a horizontal posture or a horizontal plane so that the refrigerant flow path of the primary heat exchange unit extends obliquely with respect to the horizontal direction or the horizontal plane. Configuration.

In other words, the heat exchanger is inclined with respect to the horizontal plane so that the refrigerant flow path of the primary heat exchange unit is inclined with respect to the horizontal plane, thereby reducing the connection between the primary liquid piping connection portion and the primary gas piping of the primary heat exchange unit. The height difference of the part can reduce the vertical component which rises against gravity, and can reduce the increase ratio of the primary refrigerant density in the heat exchanger, thereby reducing the increase ratio of the amount of retained refrigerant, so that the primary circuit can be reduced. The amount of refrigerant used. In this case, in the heat exchanger, heat exchange between the primary refrigerant flowing through the primary circuit and the secondary refrigerant flowing through the secondary circuit causes heat exchange between the latent heat having a large heat transfer coefficient, so even if The amount of retained refrigerant in the heat exchanger is reduced, and the heat exchange efficiency is not impaired. Further, by inclining the heat exchanger with respect to the horizontal plane, the height dimension of the upper and lower sides of the heat exchanger can be suppressed, and the cooling device can be compacted.

As described above, when the heat exchanger is disposed in the heat insulating wall portion, the heat can be prevented from being filled between the pair of peripheral members by the respective pipes connected to the heat exchanger by the restriction jig. The switch has a position offset. Further, by holding the respective pipes connected to the heat exchanger by the restriction jig, the heat exchanger can be inclined at an inclination angle θ with respect to the horizontal plane, so that the heat exchanger can be tilted with a simple operation, and heat can be manufactured. A cooling device in which the exchanger is correctly tilted at an inclination angle θ.

That is, according to the cooling device of the present invention and the method of manufacturing the same, the amount of use of the primary refrigerant can be reduced without lowering the heat exchange efficiency of the heat exchanger, and the height dimension of the heat exchanger can be suppressed to make the device It is itself compact.

Next, a preferred embodiment of the cooling device and the method of manufacturing the same according to the present invention will be described with reference to the accompanying drawings. In the embodiment, a cooling device that is used in a business of a store or the like and installed in a large-sized refrigerator that can store a large amount of articles such as vegetables or meat is described as an example. In addition, the same components and configurations as those described in the prior art are denoted by the same reference numerals.

[Example 1]

As shown in Fig. 1, the refrigerator 10 of the first embodiment includes a casing 12 having a heat insulating structure in which a storage chamber (closed space) 14 is partitioned, and a housing 12 provided above the casing 12 and made of metal The plate 18 constitutes a cabinet 16 of the outer wall. In the casing 12, the opening portion 12a which is opened to the front side and serves as an entrance and exit of the article is opened in communication with the storage chamber 14. Further, the heat insulating door 22 is rotatably disposed at a front portion of the casing 12 by a hinge (not shown), and the heat insulating door 22 is opened to allow the article to enter and exit the storage chamber 14 through the opening portion 12a, and The storage chamber 14 can be sealed by closing the heat insulating door 22.

A machine room (open space) 20 (refer to FIG. 2) is partitioned inside the cabinet 16, and the machine room 20 is provided with a part of a cooling device 32 for cooling the storage chamber 14 and for controlling the cooling device. 32 control power box (not shown). A bottom plate (insulation wall portion) 24 is provided at the bottom of the machine room 20, and the bottom plate 24 is placed on the top plate 12b of the casing 12 and serves as a common bottom plate of the machine disposed in the machine room 20. Further, an air passage hole (not shown) communicating with the machine room 20 is formed at an appropriate portion of the metal plate 18 constituting the outer wall of the cabinet 16, and the gas atmosphere and the outside air in the machine room 20 can be made through the air circulation hole. Replace it.

A cooling pipe 26 is disposed at an upper portion of the storage chamber 14 at a predetermined distance from a lower surface of the top plate 12b of the casing 12, and the cooling pipe 26 faces the notch 12c opened through the top plate 12b of the casing 12. A cooling chamber 28 is partitioned between the bottom plates 24 on the storage chamber 14 side. The cooling chamber 28 communicates with the storage chamber 14 via a suction port 26a formed on the front side of the bottom of the cooling pipe 26 and a cold air outlet 26b formed on the rear side, and is configured as a part of the storage chamber 14 of the closed space. A blower fan 30 is disposed in the suction port 26a. By driving the blower fan 30, the air in the storage chamber 14 can be sent from the suction port 26a to the cooling chamber 28, and the cold air in the cooling chamber 28 can be sent out from the cold air outlet 26b to the storage. Room 14. The notch 12c of the top plate 12b is hermetically sealed by the bottom plate 24, and the storage chamber 14 (the cooling chamber 28) and the machine room 20 are separated by the bottom plate 24 to form independent spaces (see Fig. 1).

As shown in Fig. 2, the cooling device 32 employs a secondary loop refrigeration circuit that is connected (series) through a tilted plate heat exchanger HE: forcibly circulating the primary refrigerant. The mechanical compression primary circuit 34 and the secondary circuit 44 of the secondary circuit 44 formed by a thermosiphon that naturally convects the secondary refrigerant. The plate heat exchanger HE includes a primary heat exchange unit 36 that constitutes the primary circuit 34, and a secondary heat exchange unit 46 that is formed in a different system from the primary heat exchange unit 36 and constitutes the secondary circuit 44, and is disposed in the partition storage unit. The chamber 14 and the bottom plate 24 of the machine room 20 (see Fig. 1). That is, an independent refrigerant circulation path is formed in each of the primary circuit 34 and the secondary circuit 44. In addition, as the primary refrigerant circulating in the primary circuit 34, an HC-based refrigerant such as butane or propane having excellent refrigerant properties such as evaporation heat or saturation pressure, or ammonia may be used as the circulation to the secondary circuit 44. For the secondary refrigerant, carbon dioxide which is highly toxic, flammable and corrosive can be used.

(primary loop)

The primary circuit 34 includes a compressor CM for compressing the primary vapor phase refrigerant, a condenser CD for liquefying the compressed primary refrigerant, and an expansion valve EV for lowering the pressure of the primary refrigerant in the liquid phase; The exchange unit 36 is provided in the plate heat exchanger HE to evaporate the liquid primary refrigerant. Further, in the primary circuit (34), the condenser CD, the expansion valve (EV), and the primary heat exchange unit (36) are connected to the primary liquid pipe (38) through which the liquid phase primary refrigerant is supplied to supply the primary gas pipe 40 of the gas phase primary refrigerant. The primary heat exchange unit 36, the compressor CM, and the condenser CD are connected (see Fig. 2). That is, in the primary circuit 34, the primary refrigerant is compressed in accordance with the compressor CM, the condenser CD, the expansion valve EV, and the primary heat exchange unit 36 (plate heat exchanger HE) by the compression of the primary refrigerant generated by the compressor CM. The order of the compressor CM is forced to circulate, and the plate heat exchanger HE is cooled by vaporizing the liquid phase primary refrigerant in the primary heat exchange unit 36 (see Fig. 3).

Further, the compressor CM and the condenser CD are disposed on the bottom plate 24 in the machine room 20, and a condenser fan FM for forcibly cooling the condenser CD is also disposed opposite to the condenser CD. On the bottom plate 24. That is, the outside air is sent to the machine room 20 through the air flow hole opened in the metal plate 18 by the driving of the condenser fan FM, and exchanges heat with the condenser CD and the compressor CM. Further, the control electric box is disposed in the machine room 20 at a position (in the first embodiment, the side portion of the machine room 20) that does not interfere with the flow of air generated by the condenser fan FM.

(secondary circuit)

The secondary circuit 44 includes a secondary heat exchange unit 46 installed in the plate heat exchanger HE for liquefying the secondary refrigerant in the gas phase, and an evaporator EP for vaporizing the secondary refrigerant in the liquid phase (refer to 2 picture). Further, as a pipe connecting the secondary heat exchange unit 46 and the evaporator EP, the secondary circuit 44 has a secondary liquid pipe 48 for secondary heat exchange of the liquid secondary refrigerant under the action of gravity. The portion 46 is introduced into the evaporator EP; and the secondary gas pipe 50 is used to introduce the vapor-phase secondary refrigerant from the evaporator EP into the secondary heat exchange portion 46. Here, the evaporator EP is disposed in the cooling chamber 28 partitioned below the bottom plate 24, and the evaporator EP is located below the secondary heat exchange portion 46 (plate heat exchanger HE) disposed in the bottom plate 24 The way it is composed. In other words, in the secondary circuit 44 in which the evaporator EP is disposed below the secondary heat exchange unit 46 (plate heat exchanger HE), the plate is forcedly cooled by the operation of the compressor CM of the primary circuit 34. The liquid secondary refrigerating medium condensed in the heat exchanger HE (secondary heat exchange unit 46) flows down the evaporator EP under the action of gravity, and the liquid secondary refrigerating medium flows down in the evaporator EP and the cooling chamber 28 (the storage chamber) The air inside 14) is evaporated by heat exchange, whereby it returns to the secondary heat exchange unit 46 again, and the refrigerant is circulated in this manner. Further, in the secondary circuit 44, the expansion tank 54 is connected to the middle of the secondary gas pipe 50, and when the cooling device 32 is stopped, the pressure of the secondary refrigerant that is not liquefied at normal temperature is suppressed (see Fig. 2). .

Here, the evaporator EP has an evaporation tube (refrigerant path) 52 in which a pipe is meandering, and an inflow end 52a of the evaporation pipe 52 connected to the secondary liquid pipe 48 is provided at an upper portion of the evaporator EP, and is connected to the above. The outflow end 52b of the evaporation pipe 52 of the secondary gas pipe 50 is provided in the lower portion of the evaporator EP (refer to Fig. 2). That is, the evaporator EP is formed such that the inflow end 52a of the evaporation tube 52 is located above the outflow end 52b. Further, the evaporation tube 52 is formed to extend between the inflow end 52a and the upper end of the outflow end 52b, and the liquid secondary secondary refrigerant flowing into the evaporation tube 52 is diffused by gravity to the side of the outflow end 52b. Import. More specifically, the piping of the evaporation tube 52 is formed in such a manner that the inclined straight portions are in a top-down relationship and in a meandering state, and a meandering shape is formed in a manner in which the curved portions are laterally separated, and the piping is flowed in from the same direction. The end 52a side is configured to be inclined downward toward the outflow end 52b side.

(plate heat exchanger)

As shown in Fig. 3, the plate heat exchanger HE is configured such that a plurality of plates 60 are arranged side by side at a desired interval, and are formed in parallel between the opposing plates 60 and 60. There are a plurality of first flow paths 60a constituting the primary heat exchange unit 36 of the primary circuit 34, and a second flow path 60b constituting the secondary heat exchange unit 46 of the secondary circuit 44. Here, the first flow path 60a and the second flow path 60b are independently formed so as to be alternately positioned in the overlapping direction of the plate 60, and the primary liquid pipe 38 and the primary gas pipe 40 are respectively associated with each of the first flows. The road 60a is connected to each other, and the secondary liquid pipe 48 and the secondary gas pipe 50 are connected to the respective second flow paths 60b. In other words, in the plate heat exchanger HE, the primary refrigerant and the secondary refrigerant are independently flowed to the adjacent first and second flow passages 60a and 60b, whereby the primary refrigerant and the secondary refrigerant can be passed through the respective plates 60. A heat exchange is reached. Further, the plate heat exchanger has an advantage that it is easy to change the function.

Here, as shown in FIG. 3, the plate heat exchanger HE is disposed in the bottom plate 24 such that the first and second flow paths 60a and 60b intersect with each other at a desired inclination angle θ with respect to a horizontal plane. Refer to Figure 4). Further, the primary liquid pipe 38 and the primary gas pipe 40 are connected to the opposing surface side (inclined upper side) of the plate heat exchanger HE and the machine chamber 20, and the opposing direction of the plate heat exchanger HE and the storage chamber 14 The secondary liquid pipe 48 and the secondary gas pipe 50 are connected to the surface side (the inclined lower side). Further, the primary liquid pipe 38 and the secondary liquid pipe 48 are on the same end side of the plate heat exchanger HE (on the oblique lower end side in FIGS. 3 and 4) and the respective heat exchange portions. 36 and 46 are connected, and the primary gas pipe 40 and the secondary gas pipe 50 are on the end side separated from the primary liquid pipe 38 and the secondary liquid pipe 48 of the plate heat exchanger HE (Figs. 3 and 4). The middle portion is connected to each of the corresponding heat exchange portions 36, 46 on the inclined upper end side.

In the following description, the angle formed by the plate heat exchanger HE and the horizontal plane is indicated by the inclination angle θ with reference to the end side of the liquid pipes 38 and 48 connected to the plate heat exchanger HE. In addition, the inclination angle θ when the plate heat exchanger HE is inclined upward from the primary liquid pipe 38 and the secondary liquid pipe 48 toward the primary gas pipe 40 and the secondary gas pipe 50 is set to a positive value, and the plate heat exchanger HE is used. The inclination angle θ when tilted downward is set to a negative value.

Here, the plate heat exchanger HE is disposed on the bottom plate 24 such that the inclination angle θ is in the range of -4° < θ ≦ 45°. When the inclination angle θ is set to θ>45°, the height dimension of the inclined plate heat exchanger HE is too large, and it is difficult to arrange the plate heat exchanger HE in the bottom plate 24. Further, by setting the inclination angle θ of the plate heat exchanger HE to θ > -4°, the secondary refrigerant can be made from the secondary gas pipe 50 toward the secondary heat exchange unit 46 of the secondary circuit 44. The secondary liquid pipe 48 naturally circulates to exhibit a desired refrigeration capacity. On the other hand, when the inclination angle θ is set to θ ≦ -4°, secondary refrigerant is supplied from the secondary liquid piping in the secondary heat exchange unit 46. 48 circulates toward the secondary gas pipe 50 to lower the refrigeration capacity. In addition, the circulation of the secondary refrigerant from the secondary gas pipe 50 to the secondary liquid pipe 48 in the secondary heat exchange unit 46 is referred to as a positive cycle, and the secondary refrigerant is circulated from the secondary liquid pipe 48 to the secondary gas pipe 50. It is called the reverse cycle. Further, in the secondary heat exchange unit 46, when the secondary refrigerant is circulated and the plate heat exchanger HE is disposed in the bottom plate 24, the inclination angle θ is set to -4° < θ ≦ 8 ° is more suitable. When the inclination angle θ is set to θ>8°, the bottom plate 24 is thickened to a thickness larger than the thickness required to achieve heat insulation of the storage chamber 14 and the machine room 20.

Further, in the plate heat exchanger HE, the distance between the opposing plates 60 and 60 in the second flow path 60b is set to a narrow relationship of, for example, about 1 mm, so that the liquid secondary refrigerant has a viscous force or surface tension. In the lower portion of the second flow path 60b (secondary heat exchange unit 46) on the secondary circuit 44 side, a so-called liquid seal that is clogged by the liquid secondary refrigerant is formed (see FIG. 3). In the first embodiment, the liquid sealing portion 62 (see FIG. 3) generated in the second flow path 60b of the secondary heat exchange unit 46 is caused to flow to the secondary refrigerant in the gas phase by the flow of the liquid secondary refrigerant. The function of the resistance portion prevents the gas phase secondary refrigerant from flowing back in the evaporator EP from flowing back.

Next, a method of disposing the plate heat exchanger HE with respect to the horizontal plane at an inclination angle θ will be described. In the first embodiment, as shown in Fig. 8, a projection 25 is provided between the outer peripheral members 24a and 24a constituting the outer surface of the bottom plate 24 and the inclined upper end side of the plate heat exchanger HE, and the plate type heat exchange is performed. The device HE is configured to be positioned with respect to the peripheral member 24a at a predetermined inclination angle θ. Here, the protrusions 25 are provided on any of the outer members 24a and 24a of the bottom plate 24 or the plate heat exchanger HE. Further, the protruding portion 25 is formed of a member having a heat insulating function such as foamed styrene. Further, in the peripheral members 24a and 24a, through holes (not shown) through which the pipes 38, 48, 40, and 50 connected to the plate heat exchanger HE are inserted are provided, and the joint filler is used ( Not shown) seals the gap between each of the pipes 38, 48, 40, 50 and the through hole.

Further, in a state where the plate heat exchanger HE is inclined with respect to the peripheral member 24a of the bottom plate 24, the outer sides of the respective peripheral members 24a are fixed by predetermined foaming jigs 72, 72, and fixed with the plate heat by the first restriction jig 74. The primary liquid pipe 38 and the primary gas pipe 40 connected to the exchanger HE are fixed to the secondary liquid pipe 48 and the secondary gas pipe 50 by the second restriction jig 76. In this state, the foamed material is filled between the peripheral members 24a and 24a and hardened, and after the foamed material is hardened, the clamps 72, 74, and 76 are respectively removed, whereby the plate heat exchanger can be used. The HE is disposed in the bottom plate 24 in an inclined state. Then, by placing the bottom plate 24 horizontally on the top plate 12b of the casing 12 of the refrigerator 10, the plate heat exchanger HE disposed in the bottom plate 24 is inclined at an inclination angle θ with respect to a horizontal plane.

[The role of Example 1]

Next, the action of the cooling device of the first embodiment will be described.

First of all. The case where the plate heat exchanger HE is disposed at an inclination angle θ of 4° ≦ θ ≦ 45° will be described. In the cooling device 32, when the cooling operation is started, the circulation of the refrigerant is started in the primary circuit 34 and the secondary circuit 44, respectively. At this time, in the primary circuit 34, the compressor CM and the condenser fan FM are driven, and the gas phase primary refrigerant compressed by the compressor CM is supplied to the condenser CD through the primary gas pipe 40, and then, by the condenser fan FM The generated forced cooling is condensed and liquefied, whereby a liquid phase primary refrigerant can be obtained. The liquid phase primary refrigerant is depressurized by the expansion valve EV via the primary liquid pipe 38, and then captured by the secondary refrigerant flowing through the secondary heat exchange unit 46 in the primary heat exchange unit 36 of the plate heat exchanger HE. Heat (endothermic) and expand and vaporize in one fell swoop. That is, the primary circuit 34 has a function of forcibly cooling the plate heat exchanger HE (secondary heat exchange portion 46). Then, the primary vapor phase refrigerant evaporated in the primary heat exchange unit 36 is returned to the compressor CM via the primary gas pipe 40, and the forced circulation is repeated.

On the other hand, in the secondary circuit 44, the secondary heat exchange unit 46 (plate heat exchanger HE) can be cooled by the primary refrigerant circulating in the primary circuit 34, so that it is in the secondary heat exchange unit 46. The gas phase secondary refrigerant condenses and changes phase to a liquid secondary refrigerant. Here, in the state where the plate heat exchanger HE is inclined at an inclination angle θ of 4°≦θ≦45°, the connection portion of the secondary liquid pipe 48 in the secondary heat exchange unit 46 (plate heat exchanger HE) It is located below the connection portion of the secondary gas pipe 50. In other words, the height difference (fall) generated between the connection portion of the secondary liquid pipe 48 and the connection portion of the secondary gas pipe 50 is used to change the liquid phase from the gas phase to the liquid phase to increase the specific gravity. The refrigerant naturally flows down by the gravity along the second flow path 60b of the secondary heat exchange unit 46. Further, in the secondary circuit 44, the secondary heat exchange unit 46 is disposed in the bottom plate 24, and on the other hand, the evaporator EP is disposed in the cooling chamber 28 located below the bottom plate 24, thereby being subjected to secondary heat. A gap is provided between the exchange portion 46 and the evaporator EP. Therefore, the liquid-phase secondary refrigerant flows naturally toward the evaporator EP by the action of gravity via the secondary liquid pipe 48 connected to the secondary heat exchange portion 46. The liquid-phase secondary refrigerant exchanges heat with the air in the cooling chamber 28 in the process of flowing through the evaporation tube 52 of the evaporator EP, and evaporates to change the state into a vapor-phase secondary refrigerant. Then, the vapor-phase secondary refrigerant is refluxed from the evaporator EP to the secondary heat exchange unit 46 via the secondary gas pipe 50, and it is not necessary to use a power such as a pump or a motor in the secondary circuit 44, and the secondary refrigerant can be simply configured to be repeated. Perform a natural cycle.

The air sucked from the suction port 26a into the storage chamber 14 of the cooling chamber 28 by the blower fan 30 is blown to the cooled evaporator EP to exchange heat with the evaporator EP, and is heated to the evaporator WP. The exchanged cold air is blown from the cooling chamber 28 to the storage chamber 14 through the cold air blowing port 26b, thereby cooling the storage chamber 14. Then, the air whose temperature has risen after cooling the storage chamber 14 is returned to the cooling chamber 28 via the suction port 26a, and is circulated repeatedly, whereby the inside of the storage chamber 14 is cooled to a predetermined temperature.

As described above, in the above-described cooling device 32, the primary circuit 34 and the secondary circuit 44 are connected by the plate heat exchanger HE, whereby the primary heat exchange portion 36 and the secondary heat exchange portion 46 of the plate heat exchanger HE are The primary refrigerant of the primary circuit 34 and the secondary refrigerant of the secondary circuit 44 are subjected to heat exchange by evaporation and condensation. In the plate heat exchanger HE of the first embodiment, the primary refrigerant in the primary heat exchange unit 36 and the secondary refrigerant in the secondary heat exchange unit 46 are configured to exchange heat with each other's latent heat. Efficient heat exchange can be performed as compared to heat exchange using sensible heat.

Here, in comparison with the case where the plate heat exchanger HE is disposed in an upright state, the height difference between the primary liquid pipe 38 and the primary gas pipe 40 can be reduced by tilting the plate heat exchanger HE, and the resistance can be suppressed. The density of the primary refrigerant that evaporates while flowing while flowing. Therefore, the amount of primary refrigerant used in the primary circuit 34 can be reduced as compared with the case where the plate heat exchanger HE is placed in an upright state. By reducing the amount of refrigerant required for the primary circuit 34, it is possible to avoid exceeding the upper limit of the amount of refrigerant used by the law, and the range of options for the type of refrigerant used as the primary refrigerant can be expanded.

In addition, when the plate heat exchanger HE is disposed obliquely, the height difference between the secondary liquid pipe 48 and the secondary gas pipe 50 is also reduced, so that the flow rate of the secondary refrigerant generated by the gravity action is reduced. Therefore, in the form of heat exchange by sensible heat having a low heat transfer coefficient, the heat exchange efficiency between the primary refrigerant and the secondary refrigerant is lowered to lower the cooling ability, and therefore it is generally impossible to use. On the other hand, in the cooling device 32 of the first embodiment, the primary circuit 34 and the secondary circuit 44 are connected by the plate heat exchanger HE, and the primary refrigerant of the primary circuit 34 and the secondary circuit 44 are provided in the heat exchanger HE. The secondary refrigerant is formed by heat exchange under evaporation and condensation. That is, since the heat exchange coefficient generated by the latent heat which is much higher than the sensible heat is performed in the plate heat exchanger HE, even if the plate heat exchanger HE is disposed obliquely, the gravity of the secondary refrigerant is generated. The natural downflow is reduced, and the heat exchange amount in the heat exchanger HE is also prevented from being lowered, and the cooling capacity of the cooling device 32 is not impaired.

Next, a description will be given of a case where the plate heat exchanger HE is disposed at an inclination angle θ of -4° < θ < 4°. Even in this case, the flow of the primary refrigerant in the primary circuit 34 side is the same as the case where the plate heat exchanger HE is disposed at an inclination angle θ of 4° ≦ θ ≦ 45°. In other words, compared with the case where the plate heat exchanger HE is disposed in an upright state, the difference in height between the primary liquid pipe 38 and the primary gas pipe 40 can be reduced, so that the amount of use of the primary refrigerant can be reduced.

On the other hand, when the plate heat exchanger HE is inclined to a range in which the inclination angle θ is -4° < θ < 4°, the connection portion of the secondary liquid pipe 48 of the secondary heat exchange unit 46 and the secondary gas pipe are connected. The height difference (drop) generated between the joint portions of 50 is small, and the circulation direction of the secondary refrigerant generated by the gravity action cannot be determined. Therefore, it is expected that the refrigeration capacity of the cooling device 2 is lowered. Here, in a state where the plate heat exchanger HE is inclined to a range in which the inclination angle θ is −4<θ<4°, since the primary refrigerant changes state with evaporation, the liquid of the primary heat exchange unit 36 The temperature of the inflow side of the primary refrigerant is lower than the temperature of the outflow side of the primary refrigerant of the gas phase (Fig. 5(a)). In other words, in the secondary heat exchange unit 46, the temperature on the side of the secondary liquid pipe 48 is lower than the temperature on the side of the secondary gas pipe 50. On the other hand, in the secondary heat exchange unit 46, since the vapor-phase secondary refrigerant condenses and changes phase to a liquid-phase secondary refrigerant, the liquid-phase secondary refrigerant converges (refrigerant flow) at a low temperature at which condensation is high. The side (that is, the side of the secondary liquid pipe 48), and the liquid-phase secondary refrigerant can flow down to the evaporator EP via the secondary liquid pipe 48. According to this, even if the plate heat exchanger HE is inclined so that the inclination angle θ is in the range of -4° < θ < 4°, the secondary refrigerant can be determined to be positive by the refrigerant flow of the secondary heat exchange unit 46. Since the circulation direction of the cycle is maintained, the refrigeration capacity of the cooling device 32 can be maintained (see Fig. 5(a)). When the inclination angle θ of the plate heat exchanger HE is θ ≦ -4° and the plate heat exchanger HE is inclined, the liquid-phase secondary refrigerant is caused to flow from the secondary liquid pipe 48 side to the secondary gas pipe 50 due to the drop. The gravity action in the side flow exceeds the confluence of the liquid secondary refrigerant to the secondary liquid pipe 48 side due to the temperature difference of the secondary heat exchange portion 46, and the possibility of reversing the circulation direction becomes high.

When the cooling of the storage chamber 14 (cooling chamber 28) is sufficiently performed, and the amount of heat exchange between the air in the storage chamber 14 (cooling chamber 28) and the secondary refrigerant is reduced, the heat between the primary refrigerant and the secondary refrigerant is increased. The amount of exchange will also be reduced (ie the freezing load will be reduced). When the freezing load is reduced, the liquid-phase primary refrigerant reaches the outflow side (the primary gas piping 40 side) of the primary heat exchange unit 36 to be saturated. At this time, since the temperature glide occurs due to the influence of the pressure loss in the primary heat exchange unit 36, the temperature of the outflow side (primary gas pipe 40 side) of the primary heat exchange unit 36 is higher than that of the inflow side (primary liquid) The temperature at the side of the pipe 38 is low, and the reversal of the temperature gradient is reduced (refer to Fig. 5(b)). At this time, since the secondary refrigerant in the secondary circuit 44 is converged on the low temperature side where the condensation action is high (that is, on the side of the secondary gas pipe 50), the circulation direction of the secondary refrigerant is reversed.

Here, in the plate heat exchanger HE of the first embodiment, the primary liquid pipe 38 of the primary circuit 34 and the secondary liquid pipe 48 of the secondary circuit 44 are disposed on the same end side, and the primary circuit 34 is provided. Since the primary gas pipe 40 and the secondary gas pipe 50 of the secondary circuit 44 are provided on the same end side, the primary refrigerant and the secondary refrigerant in the plate heat exchanger HE will be opposed to each other during normal operation. And efficient heat exchange between the primary refrigerant and the secondary refrigerant. On the other hand, when the refrigeration load of the cooling device 32 is reduced and the flow direction of the secondary refrigerant is reversed, since the primary refrigerant and the secondary refrigerant in the plate heat exchanger HE are parallel flow, the temperature difference between the fluids is also higher than that. The temperature difference of the counterflow is large, and the heat exchange efficiency between the primary refrigerant and the secondary refrigerant is lowered. In other words, in the cooling device 32 of the first embodiment, when the cooling chamber 32 is cooled and the cooling capacity of the cooling device 32 is excessive, the cooling capacity can be automatically suppressed by reversing the circulation direction of the secondary refrigerant. Therefore, since it is not necessary to provide a special component such as a solenoid valve, and the refrigeration capacity of the cooling device 32 is controlled in accordance with the temperature of the storage chamber 14, it is possible to reduce the cost of the number of components and to cause a failure such as a failure. Therefore, the reliability of the operation of the cooling device 32 is improved.

In the secondary circuit 44 of the cooling device 32 of the first embodiment, the inflow end 52a (the connection portion with the secondary liquid pipe 48) of the evaporation pipe 52 of the evaporator EP is disposed at the upper portion of the evaporator EP, and The outflow end 52b (the connection portion with the secondary gas pipe 50) is disposed at the lower portion of the evaporator EP so that the inflow end 52a is located above the outflow end 52b to cause a drop between the inflow end 52a and the outflow end 52b. Further, the evaporation tube 52 has a meandering shape in which the straight portion overlaps the upper and lower sides between the outflow end 52b and the inflow end 52a, and a pipe is formed in such a manner as to be inclined downward from the inflow end 52a side toward the outflow end 52b side. . In other words, when the secondary refrigerant is in the positive circulation, the entire evaporation direction of the secondary refrigerant becomes a downward gradient toward the front side of the secondary refrigerant, so that the inflow end 52a (the secondary liquid pipe 48) can flow from the inflow end 52a (the secondary liquid pipe 48). The liquid-phase secondary refrigerant is guided by gravity to the side of the outflow end 52b (secondary gas pipe 50) while being evaporating. Therefore, in the normal operation of the cooling device 32, in the evaporator EP, the liquid secondary refrigerant will stay near the inflow end 52a of the evaporation tube 52, and will not preferentially evaporate near the inflow end 52a, and the secondary refrigerant will The pipe is naturally diffused to the side of the outflow end 52b, whereby the heat transfer area can be widely ensured to improve the heat exchange efficiency of the evaporator EP (refer to Fig. 6).

On the other hand, when the refrigeration load of the cooling device 32 is reduced and the flow direction of the secondary refrigerant is reversed, the liquid secondary refrigerant flows into the evaporator EP from the side of the secondary gas pipe 50 (that is, the side of the outflow port 52b), and The vapor-phase secondary refrigerant evaporated in the evaporator EP flows out from the secondary liquid pipe 48 (i.e., the side of the inflow end 52a). That is, when the flow direction of the secondary refrigerant is reversed, since the front side of the secondary refrigerant in the circulation direction of the secondary circuit becomes an upward gradient in the evaporator EP, the liquid secondary refrigerant flowing into the evaporation pipe 52 is gravity-dependent. The action stays in the vicinity of the outflow end 52b of the evaporation tube 52 to preferentially evaporate, and the heat transfer area becomes smaller as opposed to the normal operation, so that the heat exchange efficiency of the evaporator EP is lowered (refer to Fig. 7). In other words, in the cooling device 32 of the first embodiment, when the cooling chamber 32 is cooled and the cooling capacity of the cooling device 32 is excessive, the heat exchange efficiency between the primary refrigerant and the secondary refrigerant can be reduced. The heat exchange efficiency in the evaporator EP is lowered to automatically suppress the cooling ability.

Further, in the plate type heat exchanger HE of the first embodiment, the peripheral members 24a, 24a of the bottom plate 24 or the plate heat exchanger HE are provided with projections 25 to distribute the plate heat exchanger HE to the peripheral member 24a. Then, the plate heat exchanger HE is inclined at a predetermined inclination angle θ, and in this state, the foamed material is filled/hardened between the peripheral members 24a and 24a. That is, since the plate heat exchanger HE can be inclined at the inclination angle θ by providing only the above-described protrusions 25, the positioning of the plate heat exchanger HE can be easily performed. In addition, the primary liquid pipe 38 and the primary gas pipe 40 connected to the plate heat exchanger HE are fixed by the first restriction jig 74 before the foaming material is filled between the outer peripheral members 24a and 24a, and the second liquid pipe 40 is fixed. The restriction jig 76 is configured to fix the secondary liquid pipe 48 and the secondary gas pipe 50, respectively, so that the plate heat exchanger HE can be prevented from being displaced when the foam material is filled/hardened, and the plate heat exchanger can be used. The HE is surely held at a predetermined inclination angle θ.

Further, by arranging the plate heat exchanger HE in the bottom plate 24 for insulating the storage chamber 14 and the machine room 20, heat loss of the plate heat exchanger HE can be prevented to achieve a primary refrigerant and Since the heat exchange efficiency of the secondary refrigerant is improved, it is not necessary to cover the outer circumference of the plate heat exchanger HE with a separately provided heat insulating material. Therefore, it is possible to reduce the cost by reducing the number of parts, and it is possible to achieve a simplification of the manufacturing steps. In particular, since the bottom plate 24 that is thermally insulated between the storage chamber 14 and the machine room 20 is made of a foamed material having a high heat insulating function, it has a heat insulating material attached to the plate heat exchanger HE. It is possible to improve the heat insulating function and to effectively reduce the heat loss.

In addition, by embedding the plate heat exchanger HE in the bottom plate 24, the secondary liquid pipe 48 and the secondary gas pipe 50 that connect the storage chamber 14 (the cooling chamber 28) and the plate heat exchanger HE can be respectively piped to a low temperature. In comparison with the conventional structure in which the plate heat exchanger HE is disposed in the machine room 20 and the secondary liquid pipe 48 and the secondary gas pipe 50 are piped in the machine room 20, heat loss can be significantly reduced. Further, since the secondary liquid pipe 48 and the secondary gas pipe 50 are only piped in the low temperature region (the cooling chamber 28), it is not necessary to provide a heat insulating material that heats the pipes 48 and 50, and the cost can be reduced. Reduce the advantages. Further, by supporting the plate heat exchanger HE with the foamed material of the bottom plate 24, it is not necessary to separately provide a supporting member for supporting the plate heat exchanger HE, and simplification of the structure and reduction in the number of parts can be achieved. The cost is reduced.

Further, by embedding the plate heat exchanger HE in the bottom plate 24, a space can be secured in the machine room 20, and the condenser CD, the condenser fan FM, the compressor CM, and the expansion tank 54 disposed in the machine room 20 can be disposed. The freedom of configuration of other components is improved. Further, in the cooling device 32 of the first embodiment, the air blown from the front side of the cabinet 16 to the machine room 20 and exchanged with the condenser CD and the compressor CM by the driving of the condenser fan FM is blown. The expansion tank 54 is heated to the expansion tank 54. Here, the amount of the secondary refrigerant retained in the expansion tank 54 varies depending on the pressure and the temperature, and the pressure is dependent on the evaporation temperature determined by the operating conditions and the like in the primary circuit 34, and thus cannot be changed. Therefore, by raising the temperature of the expansion tank 54 by the heat of the primary circuit 34, the density of the secondary refrigerant in the expansion tank 54 is lowered, so that the amount of the secondary refrigerant remaining in the expansion tank 54 can be reduced. When the amount of the secondary refrigerant remaining in the expansion tank 54 is reduced, there is an advantage that the amount of the secondary refrigerant in the secondary circuit 44 can be reduced.

[Example 2]

Next, the cooling device of the second embodiment will be described. The cooling device of the second embodiment has substantially the same configuration as the cooling device 32 described in the first embodiment. Therefore, members having the same functions and the same reference numerals will be given, and detailed description thereof will be omitted.

In the cooling device 32 of the second embodiment, the expansion valve EV between the condenser CD and the primary heat exchange unit 36, which is provided in the primary liquid pipe 38 of the primary circuit 34, is provided with a primary refrigerant for detecting the flow of the liquid. Temperature-detection type expansion valve whose temperature can be changed by the temperature. Specifically, when the temperature of the liquid-phase primary refrigerant flowing through the primary liquid pipe 38 rises to a predetermined temperature or higher, the expansion valve EV reduces the amount of primary refrigerant flowing to the primary heat exchange unit 36 by reducing the throttle degree. The way to adjust.

That is, in the state where the plate heat exchanger HE is disposed at an inclination angle θ of -4° < θ < 4° as described above, between the air in the storage chamber 14 (cooling chamber 28) and the secondary refrigerant When the amount of heat exchange is reduced and the refrigeration load is reduced, the liquid-phase primary refrigerant reaches the outflow side (the primary gas pipe 40 side) of the primary heat exchange unit 36 in a saturated state, and is generated by the influence of the pressure loss in the primary heat exchange unit 36. Temperature glide. In the cooling device 32 of the second embodiment, when the temperature is slid in the primary heat exchange unit 36 and the liquid-phase primary refrigerant is raised to a predetermined temperature, the expansion valve EV is configured to reduce the liquid flowing to the primary heat exchange unit 36. The throttle is adjusted by the amount of refrigerant in one phase. In other words, by reducing the amount of the primary refrigerant in the primary heat exchange portion 36 by the expansion valve EV, the occurrence of temperature slip in the primary heat exchange portion 36 can be prevented, and the inflow in the primary heat exchange portion 36 can be caused. The temperature of the side (the side of the primary liquid pipe 38) is maintained at a lower temperature than the temperature of the outflow side (the side of the primary gas pipe 40). Therefore, in the secondary circuit 44, the liquid-phase secondary refrigerant can be flowed to the low-temperature side where the condensation action is high (that is, on the side of the secondary liquid pipe 48), so that the reversal phenomenon of the secondary refrigerant in the circulation direction can be prevented. In addition, since the amount of primary refrigerant that has flowed through the primary heat exchange unit 36 in the plate heat exchanger HE is reduced, the amount of heat exchange between the primary refrigerant and the secondary refrigerant can be reduced, so that it is cooled in the storage chamber 14. Further, when the cooling capacity of the cooling device 32 is excessive, the cooling capacity can be automatically suppressed without reversing the circulation direction of the secondary refrigerant.

As described above, in the cooling device 32 of the second embodiment, by providing the temperature detecting type expansion valve EV, even if the plate heat exchanger HE is disposed at an inclination angle θ of -4° < θ < 4°, It is also possible to maintain the natural circulation direction of the secondary refrigerant fixed and to control the cooling capacity of the cooling device 32. Further, in the second embodiment, the temperature detecting type expansion valve EV is provided in the primary circuit 34, but the capacity of the primary heat exchange unit 36 of the plate heat exchanger HE is increased or once in the primary circuit 34. The amount of refrigerant is reduced, and the temperature gradient of the primary heat exchange unit 36 can be kept constant while the refrigeration load is reduced, and the circulation direction of the secondary refrigerant of the secondary circuit 44 can be kept constant.

[Example 3]

Next, the cooling device of the third embodiment will be described. The cooling device of the third embodiment has substantially the same configuration as the cooling device 32 described in the first embodiment. Therefore, the same reference numerals will be given to members having the same functions, and detailed description thereof will be omitted.

In the third embodiment, another manufacturing method in which the plate heat exchanger HE is disposed at an inclination angle θ with respect to the horizontal plane will be described. In the cooling device 32 of the third embodiment, as shown in Fig. 9, the peripheral member 24a constituting the bottom plate 24 is formed with an inclined surface 80 having an inclination angle θ with respect to the horizontal plane, and the above-described plate type heat exchange is provided on the inclined surface 80. The HE is used to position the plate heat exchanger HE at an oblique angle θ with respect to the horizontal plane. Next, in a state where the plate heat exchanger HE is inclined with respect to the peripheral member 24a of the bottom plate 24, the outer sides of the respective peripheral members 24a are fixed by predetermined foaming jigs 72, 72, and the first restricting jig 74 is used with the plate type. The primary liquid pipe 38 and the primary gas pipe 40 connected to the heat exchanger HE are fixed, and the secondary liquid pipe 48 and the secondary gas pipe 50 are respectively fixed by the second restriction jig 76. In this state, the foamed material is filled between the peripheral members 24a and 24a and hardened, and after the foamed material is cured, the jigs 72, 74, and 76 are respectively removed, whereby the plate heat exchanger HE is The inclined state is disposed in the bottom plate 24. Thereafter, the bottom plate 24 is horizontally disposed on the top plate 12b of the casing 12 of the refrigerator 10, whereby the plate heat exchanger HE disposed in the bottom plate 24 is inclined at an inclination angle θ with respect to a horizontal plane.

That is, in the cooling device 32 of the third embodiment, the inclined surface 80 is provided on the peripheral member 24a of the bottom plate 24, so that the plate heat exchanger HE is disposed on the inclined surface 80, whereby the plate type heat exchange can be performed. The device HE is inclined at a predetermined inclination angle θ, so that the positioning of the plate heat exchanger HE can be simply performed. In the same manner as described above, the primary liquid pipe 38 and the primary gas pipe 40 connected to the plate heat exchanger HE are fixed by the first restriction jig 74 before the foaming material is filled between the outer peripheral members 24a and 24a. Since the second restriction jig 76 is configured by fixing the secondary liquid pipe 48 and the secondary gas pipe 50, it is possible to prevent the plate heat exchanger HE from being displaced when the foam material is filled/hardened, and the plate heat exchanger can be used. The HE is surely held at a predetermined inclination angle θ.

[Example 4]

Next, the cooling device of the fourth embodiment will be described. The cooling device of the fourth embodiment has substantially the same configuration as the cooling device 32 described in the first embodiment. Therefore, the same reference numerals will be given to members having the same functions, and detailed description thereof will be omitted.

In the fourth embodiment, another manufacturing method in which the plate heat exchanger HE is disposed at an inclination angle θ with respect to the horizontal plane will be described. In the cooling device 32 of the fourth embodiment, as shown in Fig. 10, the plate heat exchanger HE (the primary heat exchange portion 36 and the secondary heat exchange portion 46) is parallel with respect to the peripheral member 24a constituting the bottom plate 24. Mode setting. Further, the outer side of each of the peripheral members 24a is fixed by the predetermined foaming jigs 72 and 72, and the primary liquid pipe 38 and the primary gas pipe 40 connected to the plate heat exchanger HE are fixed by the first restriction jig 74, and the second restriction is used. The jig 76 fixes the secondary liquid pipe 48 and the secondary gas pipe 50, respectively. In this state, the foamed material is filled between the peripheral members 24a and 24a and hardened, and after the foamed material is cured, the jigs 72, 74, and 76 are respectively removed, whereby the plate heat exchanger HE is It is disposed in a posture parallel to the bottom plate 24. Thereafter, the bottom plate 24 is obliquely disposed at the inclination angle θ of the top plate 12b of the casing 12 of the refrigerator 10, whereby the plate heat exchanger HE disposed in the bottom plate 24 is inclined at an inclination angle θ with respect to a horizontal plane. And constitute.

Here, when the bottom plate 24 is placed on the casing 12 such that the peripheral member 24a is inclined at an inclination angle θ with respect to the horizontal plane, as shown in FIG. 11(a), the above-mentioned bottom plate is provided in the casing 12. The height difference is set in the portion of 24, and when the bottom plate 24 is provided in the casing 12, the bottom plate 24 can be inclined at an inclination angle θ by the height difference of the casing 12. Further, as shown in Fig. 11(b), if the support portion 82 that is suspended downward is formed at one end portion of the bottom plate 24, the bottom plate 24 can be tilted by the support portion 82 when the bottom plate 24 is placed in the case 12. The angle θ is inclined.

As described above, in the cooling device 32 of the fourth embodiment, the bottom plate 24 of the plate heat exchanger HE is embedded in parallel, and is disposed on the casing 12 so as to be inclined at an inclination angle θ with respect to the horizontal plane. The exchanger HE can also be inclined at an inclination angle θ with respect to the horizontal plane. That is, when the plate heat exchanger HE is disposed on the bottom plate 24, since it is not necessary to adjust the inclination angle of the plate heat exchanger HE itself, the manufacturing steps can be simplified. Moreover, since the inclination angle θ of the plate heat exchanger HE with respect to the horizontal plane can be adjusted by the inclination of the bottom plate 24, it is easy to perform the plate type as compared with the configuration in which the plate heat exchanger HE is obliquely disposed in the bottom plate 24. The advantage of the adjustment of the inclination angle θ of the heat exchanger HE. In the same manner as described above, the primary liquid pipe 38 and the primary gas pipe 40 connected to the plate heat exchanger HE are fixed by the first restriction jig 74 before the foaming material is filled between the outer peripheral members 24a and 24a. Since the second restriction jig 76 is configured by fixing the secondary liquid pipe 48 and the secondary gas pipe 50, it is possible to prevent the plate heat exchanger HE from being displaced when the foam material is filled/hardened.

[Example 5]

Next, the cooling device of the fifth embodiment will be described. The cooling device of the fifth embodiment has substantially the same configuration as the cooling device 32 described in the first embodiment. Therefore, the same reference numerals will be given to members having the same functions, and detailed description thereof will be omitted. Further, the configuration of the inclination angle θ of the heat exchanger described in the above-described first to fourth embodiments, the arrangement of the arrangement structure or the arrangement position, or the method of manufacturing the cooling device 32 may be suitably applied to the fifth embodiment.

In the cooling device 32 of the embodiment 5, a double-tube type heat exchanger HE1 is employed. The heat exchanger HE1 of the fifth embodiment will be specifically described. As shown in Fig. 13 or Fig. 14, the heat exchanger HE1 of the fifth embodiment has a tubular secondary heat exchange portion 46 made of a metal material excellent in thermal conductivity as an inner tube, and retains the circulation space of the primary refrigerant. On the other hand, the primary heat exchange unit 36 that is coated on the outer side of the secondary heat exchange unit 46 serves as a double tube type heat exchanger of the outer tube. Further, the primary heat exchange portion 36 is made of a metal material. Further, the heat exchanger HE1 is disposed such that the secondary heat exchange portion 46 extends in a spiral shape in which the upper and lower directions are axes, and the primary heat exchange portion 36 covers the outer side of the secondary heat exchange portion 46 and the secondary heat. The exchange portion 46 is similarly configured to extend in a spiral shape. In other words, the heat exchanger HE1 is a spiral tubular body that is formed in a ring shape in plan view (see FIG. 13), and a secondary gas pipe 50 is connected to the upper end of the secondary heat exchange unit 46 in the secondary heat exchange unit. The secondary liquid pipe 48 is connected to the lower end of the 46, and the secondary refrigerant is swirled from the upper side toward the lower side while swirling around the secondary heat exchange unit 46 along the spiral shape. On the other hand, the primary heat exchange unit 36 is connected to the primary liquid pipe 38 connected to the expansion valve EV at the lower end, and the primary gas pipe 40 connected to the compressor CM is connected to the upper end, and the primary refrigerant is swirled along the spiral shape. The flow space of the primary heat exchange unit 36 flows upward from the bottom. In other words, the heat exchanger HE1 is configured such that the flow direction of the secondary refrigerant flowing through the secondary heat exchange unit 46 and the flow direction of the primary refrigerant flowing through the primary heat exchange unit 36 are reversed.

The heat exchanger HE1 is disposed on the upper side of the compressor CM in the machine room 20, and is disposed such that the compressor CM is seated in the ring formed by the heat exchanger HE1 (refer to FIG. 1 or FIG. 2). ). Further, the heat exchanger HE1 is disposed in the machine room 20 at a position lower than the top of the condenser CD having a height higher than that of the compressor CM, and does not protrude from the machine room 20. Further, the heat exchanger HE1 is disposed on the downstream side in the flow direction of the air sent by the condenser fan FM, and is located on the path of the air flow sent by the condenser fan FM. In addition, the heat exchanger HE1 is disposed in a horizontal posture or in a posture inclined at an inclination angle θ with respect to a horizontal plane so that the refrigerant flow path of the primary heat exchange unit 36 extends obliquely with respect to the horizontal direction or the horizontal plane. Further, the heat exchanger HE1 is formed in a spiral shape, and the path in which the refrigerant flows in the lateral direction is elongated by 3 so that the size in the vertical overlapping direction is reduced, so that the entire shape is formed into a horizontally long shape. Further, the heat exchanger HE1 may be disposed in a horizontal posture.

In the heat exchanger HE1 of the fifth embodiment, the heat exchanger HE1 is used as a reference when the connection end side of the gas pipes 40 and 50 is used as a reference, and the posture is inclined toward the connection end side of the gas pipes 40 and 50. The inclination angle θ formed with the horizontal plane is also appropriately set in the range of -4° < θ ≦ 45°, 4° < θ ≦ 45, and -4° < θ < 4°, so that the first embodiment is produced. The same effect to 4.

In other words, by narrowing the heat exchanger HE1 with respect to the horizontal plane so that the refrigerant flow path of the primary heat exchange unit 36 is inclined with respect to the horizontal plane, the connection portion of the primary liquid pipe 38 in the primary heat exchange portion 36 can be reduced. The height difference of the connection portion of the primary gas pipe 40 can reduce the vertical component which rises against gravity, and can reduce the increase ratio of the primary refrigerant density in the heat exchanger HE1, thereby reducing the increase ratio of the retained refrigerant amount. Therefore, the amount of refrigerant used in the primary circuit 34 can be reduced. At this time, in the heat exchanger HE1, heat exchange between the primary refrigerant flowing through the primary circuit 34 and the secondary refrigerant flowing through the secondary circuit causes heat exchange between the latent heat having a large heat transfer coefficient. Even if the amount of retained refrigerant in the heat exchanger HE1 is reduced, the heat exchange efficiency is not impaired. Further, by inclining the heat exchanger HE1 with respect to the horizontal plane, the height dimension of the upper and lower sides of the heat exchanger HE1 can be suppressed, and the cooling device 32 can be compacted. Further, the double-casing heat exchanger HE1 has a high degree of freedom in shape and can effectively utilize the space. Here, the primary heat exchange unit 36 may be used as the inner tube, and the secondary heat exchange unit 46 may be used as the outer tube.

(Modification)

The cooling device and the method of manufacturing the same according to the present invention are not limited to the above embodiments, and various modifications can be made.

For example, in the first to fourth embodiments, the plate heat exchanger is disposed in the heat insulating wall portion. However, the present invention is not limited thereto, and the plate heat exchanger may be disposed in the open space. On the hot wall. Further, as shown in Fig. 15, the heat exchanger HE1 described in the fifth embodiment may be disposed in the heat insulating wall portion 24.

In each of the embodiments, the evaporator of the secondary circuit is configured such that the inflow end connected to the secondary liquid pipe is located higher than the outflow end connected to the secondary gas pipe, but is not limited thereto. Alternatively, the inflow end connected to the secondary liquid pipe may be located lower than the outflow end connected to the secondary gas pipe.

In each of the embodiments, the plate heat exchanger is disposed in an inclined state by providing an inclined surface on the peripheral member constituting the heat insulating wall portion or by providing a protrusion provided on the peripheral member or the plate heat exchanger. However, the plate heat exchanger may be positioned in an inclined state only by a fixture that fixes each pipe of the plate heat exchanger.

Further, as the evaporation tube of the evaporator, a so-called fin tube having fins extending in the radial direction on the outer circumference or fins extending in the radial direction on the outer circumference may be employed. A so-called spiral fintube is formed in a spiral shape. Moreover, as the pipeline of the evaporation pipe, it is also possible to adopt a system in which a plurality of (two systems) are branched at the inflow end, and the diverging evaporator tubes of the plurality of systems are extended in a downward gradient toward the front side in the circulation direction. It forms a snake, and then recombines at the outflow end.

In each of the embodiments, the evaporation tube is formed to be inclined downward from the inflow end side toward the outflow end side, but the liquefied refrigerant may be diffused under the action of gravity toward the outflow end side as well as in the piping. A part of the portion is provided to be inclined upward toward the outflow end side or a horizontally extending portion.

In each of the embodiments, the apparatus for preventing backflow of the vapor-phase secondary refrigerant is a liquid sealing portion formed in a flow path of the secondary heat exchange unit in the plate heat exchanger, but the present invention is not limited thereto. It is sufficient to provide a resistance against the flow resistance of the gas-phase secondary refrigerant between the vicinity of the connection portion of the heat exchanger and the secondary liquid pipe to the secondary liquid pipe. For example, as a configuration in which the liquid secondary refrigerant is stored in the middle of the inner bottom of the heat exchanger or the secondary liquid pipe, the head (water head) of the secondary refrigerant stored in the storage portion may be used as the resistance portion. In addition, a pipe having a large flow resistance or a pipe shape such as a throttle or a trap may be provided in the secondary liquid pipe, or a check valve inserted into the secondary liquid pipe may be used as a resistance. unit. The resistance portions of the various aspects can be used alone or in combination with the configurations of the first embodiment and the modifications to function as a resistance portion.

In each of the embodiments, the bottom plate partitioning the storage chamber and the machine room disposed in the machine room as the common substrate of the machine is configured such that air does not flow through the machine room and the storage chamber, but may be a case. The top plate is divided into a mechanical chamber and a storage chamber.

In each of the embodiments, the case where the cooling device is used in the refrigerator is described as an example, but it can also be applied to a so-called storage room such as a freezer, a freezer/refrigerator, a shos case, and a combined refrigerator. Other air conditioners, etc.

In the embodiment, an expansion valve is used as a primary circuit decompression device (throttle mechanism), but a capillary tube or other device may be employed.

In the fifth embodiment, the double-tube type heat exchanger is formed in a spiral shape in which the shaft is heated upward or downward, but may be formed by extending an appropriate path such as a meandering shape or a step shape.

10. . . Cold storage

12. . . Box

12a. . . Opening

12b. . . roof

12c. . . gap

14. . . Storage room

16. . . cabinet

18. . . Metal plate

20. . . Mechanical room

twenty two. . . Heat insulation door

twenty four. . . Bottom plate

24a. . . Peripheral component

25. . . Protrusion

26. . . Cooling tube

26a. . . suction point

26b. . . Blowout

28. . . Cooling room

30. . . Send fan

32. . . Cooling device

34. . . Primary circuit

36. . . Primary heat exchange department

38. . . Primary liquid piping

40. . . Primary gas piping

44. . . Secondary circuit

46. . . Secondary heat exchange

48. . . Secondary liquid piping

50. . . Secondary gas piping

52. . . Evaporation tube

52a. . . Inflow

52b. . . Outflow end

54. . . Expansion tank

60. . . board

60a. . . First flow path

60b. . . Second flow path

62. . . Liquid seal

72. . . Foaming fixture

74. . . First limit fixture

76. . . Second limit fixture

80. . . Inclined surface

90. . . Cooling device

94. . . Primary circuit

96. . . Primary heat exchange department

98. . . Piping

104. . . Secondary circuit

106. . . Secondary heat exchange

108. . . Another piping

110. . . Plate heat exchanger

112. . . Bottom plate

CD. . . Condenser

CM. . . compressor

EP. . . Evaporator

EV. . . Expansion valve

FM. . . Condenser fan

HE. . . Heat exchanger

HE1. . . Heat exchanger

Fig. 1 is a side sectional view showing a refrigerator which is cooled by the cooling device of the preferred embodiment 1 of the present invention.

Fig. 2 is a schematic circuit diagram showing a cooling device of the first embodiment.

Fig. 3 is a cross-sectional view showing the plate type heat exchanger of the first embodiment.

Fig. 4 is a schematic explanatory view showing an installation state of the plate type heat exchanger of the first embodiment.

Fig. 5 is a schematic explanatory view showing the relationship between the temperature gradient of the plate type heat exchanger of the first embodiment and the flow direction of the secondary refrigerant, wherein (a) shows a state in which the secondary refrigerant is in a positive cycle, and (b) shows a state in which the secondary refrigerant is in a positive cycle. The secondary refrigerant is in the state of a reverse cycle.

Fig. 6 is a cross-sectional view taken along line A-A of the evaporator shown in Fig. 2, showing a state in which the secondary refrigerant is in a positive cycle.

Fig. 7 is a cross-sectional view taken along line A-A of the evaporator shown in Fig. 2, showing a state in which the secondary refrigerant is in a reverse cycle.

Fig. 8 is a schematic explanatory view showing a method of disposing the plate heat exchanger of the second embodiment.

Fig. 9 is a schematic explanatory view showing a method of disposing the plate type heat exchanger of the third embodiment.

Fig. 10 is a schematic explanatory view showing a method of disposing the plate type heat exchanger of the fourth embodiment.

Fig. 11 is a schematic explanatory view showing a method of disposing a floor on which the plate heat exchanger of the fourth embodiment is disposed, and (a) shows a structure in which the bottom plate is inclined by the box structure, (b) A structure in which the bottom plate is inclined by the bottom plate structure.

Fig. 12 is a side sectional view showing the refrigerator which is cooled by the cooling device having the heat exchanger of the fifth embodiment.

Fig. 13 is a plan view showing a machine room of a refrigerator which is cooled by a cooling device having the heat exchanger of the fifth embodiment.

Fig. 14 is a side elevational view showing the heat exchanger of the fifth embodiment partially cut away.

Fig. 15 is a side sectional view showing the refrigerator in another arrangement example of the heat exchanger of the fifth embodiment.

Fig. 16 is a schematic view showing a conventional cooling device.

20. . . Mechanical room

twenty four. . . Bottom plate

32. . . Cooling device

34. . . Primary circuit

36. . . Primary heat exchange department

38. . . Primary liquid piping

40. . . Primary gas piping

44. . . Secondary circuit

46. . . Secondary heat exchange

48. . . Secondary liquid piping

50. . . Secondary gas piping

52. . . Evaporation tube

52a. . . Inflow

52b. . . Outflow end

54. . . Expansion tank

CD. . . Condenser

CM. . . compressor

EP. . . Evaporator

EV. . . Expansion valve

FM. . . Condenser fan

HE. . . Heat exchanger

Claims (12)

A cooling device includes a primary circuit (34) for mechanically forcibly circulating a primary refrigerant, a secondary circuit (44) for naturally circulating a secondary refrigerant, and heat exchange between the primary refrigerant and the secondary refrigerant. The heat exchanger (HE, HE1) is characterized in that the primary circuit (34) includes a compressor (CM) that compresses the primary refrigerant, and a condensation that condenses the primary refrigerant compressed by the compressor (CM). a device (CD), a decompression device (EV) for decompressing a primary refrigerant condensed by the condenser (CD), and a heat exchanger (HE, HE1) formed by the condenser (CD) a primary heat exchange unit (36) for condensing the primary refrigerant to be evaporated; and connecting the condenser (CD) to the primary liquid pipe (38) of the primary heat exchange unit (36) via the pressure reducing device (EV) to the above heat exchange One end side of the device (HE, HE1), and a primary gas pipe (40) connecting the compressor (CM) and the primary heat exchange unit (36) to the other end side of the heat exchanger (HE, HE1) In the above secondary circuit (44), the secondary circuit (44) is provided in the heat exchanger (HE, HE1) and condenses the secondary refrigerant a heat exchange unit (46) and an evaporator (EP) for evaporating the secondary refrigerant condensed by the secondary heat exchange unit (46); and connecting the secondary heat exchange unit (46) and the evaporator ( The secondary liquid pipe (48) of EP) is connected to the connection end side of the above-mentioned primary liquid pipe (38) in the above heat exchanger (HE, HE1), and is connected to the secondary heat exchange portion (46) and the evaporator The secondary gas pipe (50) of (EP) is connected to the connection end side of the primary gas pipe (40) in the heat exchanger (HE, HE1), An open space (20) in which the primary circuit (34) is disposed and a closed space (14) in which the evaporator (EP) of the secondary circuit (44) is disposed is partitioned by the heat insulating wall portion (24). The heat exchangers (HE, HE1) are disposed between a pair of peripheral members (24a, 24a) constituting the heat insulating wall portion (24), and the heat exchangers (HE, HE1) are configured to perform the above-described one time. The refrigerant flow path of the heat exchange unit (36) is disposed in a horizontal posture or a posture inclined with respect to the horizontal plane so as to extend obliquely with respect to the horizontal direction or the horizontal plane. The cooling device according to claim 1, wherein the heat exchanger is a plate heat exchanger (HE), and the plate heat exchanger (HE) is disposed in a horizontal posture or an inclined posture with respect to a horizontal plane. The cooling device according to claim 1, wherein the heat exchanger (HE1) is an outer tube constituting any one of the primary heat exchange unit (36) or the secondary heat exchange unit (46); And an inner tube that is inserted into the outer tube and constitutes the other of the primary heat exchange unit (36) or the secondary heat exchange unit (46). The cooling device according to any one of claims 1 to 3, wherein an angle θ formed by the heat exchanger (HE, HE1) and a horizontal plane is at a connection end side of the liquid piping (38, 48) As a criterion, when the posture which is inclined upward toward the connection end side of the gas piping (40, 50) is a positive value, it is set in a range of -4° < θ ≦ 45°. The cooling device according to any one of claims 1 to 3, wherein the heat exchanger (HE, HE1) forms an angle θ with a horizontal plane, When the posture of the liquid pipe (38, 48) on the side of the connection end is inclined upward toward the connection end side of the gas pipe (40, 50), it is set at 4 ° ≦ θ ≦ 45 °. The scope. The cooling device according to any one of claims 1 to 3, wherein an angle θ formed by the heat exchanger (HE, HE1) and a horizontal plane is at a connection end side of the liquid piping (38, 48) In the case where the posture which is inclined upward toward the connection end side of the gas piping (40, 50) is a positive value, it is set in a range of -4° < θ < 4°. The cooling device of claim 6, wherein the evaporator (EP) in the secondary circuit (44) is connected to the second portion by an inflow end (52a) connected to the secondary liquid pipe (48) The outflow end (52b) of the secondary gas pipe (50) is configured to be located at an upper portion. The cooling device according to any one of claims 1 to 3, wherein the heat exchanger (HE, HE1) is formed by the heat exchanger (HE, HE1) or peripheral members (24a, 24a) The protrusion (25) is configured to be inclined at an inclination angle θ with respect to a horizontal plane. The cooling device of claim 8, wherein the protrusion (25) is formed by a member having a heat insulating function. The cooling device according to any one of claims 1 to 3, wherein the heat exchanger (HE, HE1) is disposed at the peripheral member (24a) and has an inclination angle θ with respect to a horizontal plane. The inclined surface (80) is configured such that the heat exchangers (HE, HE1) are inclined at an inclination angle θ with respect to a horizontal plane. A cooling device according to any one of claims 1 to 3, wherein The heat exchanger (HE, HE1) is configured to be inclined at an inclination angle θ with respect to a horizontal plane by inclining the peripheral member (24a) with respect to a horizontal plane. A method of manufacturing a cooling device is characterized in that the heat exchanger (HE, HE1) is disposed between a pair of peripheral members (24a, 24a) constituting the heat insulating wall portion (24). The method of manufacturing a cooling device (32) according to any one of the preceding claims, wherein the heat exchanger (HE, HE1) is disposed between the pair of peripheral members (24a, 24a), and is limited by The jigs (74, 76) hold pipes (38, 40) for connecting the primary circuit (34) and the heat exchangers (HE, HE1) and for connecting the secondary circuit (44) and the heat exchanger (HE, In the state of the pipes (48, 50) of HE1), the foamed material is filled between the pair of peripheral members (24a, 24a).