JP2021076364A - Cooling device and cooling system - Google Patents

Abstract

To realize means which eases restrictions imposed by securing an effective suction head and inhibits cavitation occurring in a liquid pump at low costs.SOLUTION: A cooling device includes: a liquid receiver; a liquid pump for sending a liquid refrigerant in the liquid receiver to a cooling load; a refrigerant pipe provided between the liquid receiver and the liquid pump; and a liquid refrigerant circulation pipe in which an inlet and an outlet are connected to the liquid receiver; and a peltier element having a heat absorption surface provided at the refrigerant pipe side and a heat radiation surface provided at the circulation pipe side.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a cooling device and a cooling system including the cooling device.

As a cooling system for cooling a refrigerated warehouse or the like, for example, a primary refrigerant circuit in which a primary refrigerant such as ammonia circulates and a secondary refrigerant circuit using carbon dioxide or the like as a secondary refrigerant are provided, and the secondary is cooled by the primary refrigerant. A natural refrigerant cooling system is known in which a secondary refrigerant liquid is stored in a liquid receiver and the secondary refrigerant liquid in the liquid receiver is supplied to a cooling load such as an air cooler provided in a refrigerating warehouse by a liquid pump. In this cooling system, if the pressure drops inside the suction side piping of the liquid pump or liquid pump and cavitation occurs, the secondary refrigerant liquid cannot be sent to the cooling load, so the liquid receiver is positioned higher than the liquid pump. It is necessary to secure a net positive suction head (NPSHA) equal to or higher than the required suction head (NPSHR: Liquid Net Pumpation Head). In this case, the height dimension of the entire device becomes large, and there are restrictions on the design and the arrangement of the device. Further, when the refrigerant pressure in the liquid receiver is suddenly reduced, such as during the cooling operation after the defrost operation is completed, cavitation may occur on the suction side of the liquid pump.

In order to solve the above problems, Patent Documents 1 and 2 provide a cooling coil inside the liquid receiver or a heat exchanger on the suction side pipe of the liquid pump to cool the cooling coil and the heat exchanger. A means for preventing cavitation in the liquid pump by providing a refrigerator for supplying the medium and overcooling the liquid refrigerant flowing in the liquid receiver or the suction side pipe of the liquid pump is disclosed.

JP-A-2007-155315 Japanese Patent No. 6321568

The means disclosed in Patent Documents 1 and 2 are a refrigerator for generating a cooling medium having a temperature lower than that of the liquid refrigerant for cooling the liquid refrigerant, a heat exchanger for heat exchange between the liquid refrigerant and the cooling medium, and the same. New pipes and the like for supplying the cooling medium to the heat exchanger are required. Therefore, there is a problem that an extra installation space is required and the equipment cost is high.

This disclosure has been made in view of the above-mentioned problems, and alleviates the restrictions caused by securing net positive suction head, and suppresses cavitation generated in the liquid pump and the suction side piping of the liquid pump at low cost. The purpose is to realize the means.

In order to achieve the above object, one aspect of the cooling device according to the present disclosure is between a liquid receiver, a liquid pump for sending the liquid refrigerant in the liquid receiver to a cooling load, and the liquid receiver and the liquid pump. It has a refrigerant pipe provided in the above, a circulation pipe of the liquid refrigerant whose inlet and outlet are connected to the liquid receiver, a heat absorbing surface provided on the refrigerant pipe side, and a heat radiating surface provided on the circulation pipe side. It is equipped with a refrigerant element.

One aspect of the cooling system according to the present disclosure is a primary refrigerant circuit in which the primary refrigerant circulates, a refrigeration cycle component device including an evaporator provided in the primary refrigerant circuit, and the evaporator cooled by the primary refrigerant. A secondary refrigerant circuit for supplying the secondary refrigerant to the cooling load and a cooling device having the above configuration provided in the secondary refrigerant circuit are provided, and the liquid refrigerant is used as the secondary refrigerant in the liquid receiver. The refrigerant pipe is stored and forms a part of the secondary refrigerant circuit between the liquid receiver and the liquid pump.

According to the cooling device and the cooling system according to the present disclosure, the pressure at which the liquid refrigerant vaporizes can be reduced by supercooling the liquid refrigerant using the Pelche element. As a result, it is possible to suppress the occurrence of cavitation inside the liquid pump and the suction side piping, so that the restrictions for securing the net positive suction head can be relaxed, and the cooling device can be made compact and stable operation becomes possible. Further, unlike Patent Documents 1 and 2, since it is not necessary to newly install a refrigerator, a heat exchanger, etc., it is possible to suppress an increase in the installation space of the device and an increase in the device cost. Further, the smaller the temperature difference between the endothermic surface and the heat radiating surface of the Pelche element, the better the endothermic characteristics. However, the endothermic side liquid refrigerant and the heat radiating side liquid refrigerant are supplied from the same liquid receiver, and the temperatures of both liquid refrigerants are supplied. Since the difference is small, good endothermic properties can be obtained. Further, since the liquid refrigerant on the heat dissipation side undergoes a phase change during heat absorption and does not involve a temperature change, good endothermic characteristics can be maintained.

It is a system diagram of the refrigeration system which concerns on one Embodiment. It is a front view which shows a part of the cooling apparatus which concerns on one Embodiment. It is a partial cutting side view along the line AA in FIG. It is a Moriel diagram of the cooling device which concerns on one Embodiment. It is an enlarged view of the porous material which concerns on one Embodiment. It is a figure which shows the porous material which concerns on one Embodiment. It is a front view which shows a part of the cooling apparatus which concerns on one Embodiment. It is a partial cutting side view along the line BB in FIG. It is a graph which shows the improvement of the heat transfer coefficient by a porous material. It is a graph which shows the improvement of the heat transfer coefficient by a porous material.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, and are merely explanatory examples.
For example, expressions that represent relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" are exact. Not only does it represent such an arrangement, but it also represents a state of relative displacement with tolerances or angles and distances to the extent that the same function can be obtained.
For example, expressions such as "same", "equal", and "homogeneous" that indicate that things are in the same state not only represent exactly the same state, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
For example, an expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also an uneven portion or chamfering within a range in which the same effect can be obtained. The shape including the part and the like shall also be represented.
On the other hand, the expressions "equipped", "equipped", "equipped", "included", or "have" one component are not exclusive expressions that exclude the existence of other components.

FIG. 1 is a system diagram of a freezing system 10 according to an embodiment. The refrigeration system 10 includes a primary refrigerant circuit 12 in which the primary refrigerant circulates, and a secondary refrigerant circuit 14 in which the secondary refrigerant circulates. The primary refrigerant circuit 12 is provided with a refrigeration cycle component including an evaporator 16, and the refrigeration cycle is configured by circulating the primary refrigerant through the refrigeration cycle component. The secondary refrigerant circulating in the secondary refrigerant circuit 14 is cooled by the primary refrigerant in the evaporator 16 and condensed. The secondary refrigerant liquid condensed by the evaporator 16 is supplied to the cooling load 18 and used as a cooling heat source for the cooling load 18. For example, a natural refrigerant such as ammonia is used as the primary refrigerant, and a natural refrigerant such as carbon dioxide is used as the secondary refrigerant.

In one embodiment, the primary refrigerant circuit 12 is provided with a compressor 20, a condenser 22, an expansion valve 24, and the like as refrigerating cycle components. The primary refrigerant compressed by the compressor 20 is cooled by the condenser 22 and condensed, and the condensed primary refrigerant liquid is decompressed through the expansion valve 24 and sent to the evaporator 16 which functions as an evaporator of the primary refrigerant circuit 12. .. The primary refrigerant liquid is endothermic and vaporized from the secondary refrigerant in the evaporator 16, and the vaporized primary refrigerant is compressed again by the compressor 20.

As shown in FIG. 1, the cooling device 30 according to the embodiment includes a liquid receiver 32 for storing the liquid refrigerant, a refrigerant pipe 36 is provided between the liquid receiver 32 and the liquid pump 34, and the liquid receiver 32 is provided. The liquid refrigerant accumulated in is sent to the cooling load 18 by the liquid pump 34 via the refrigerant pipe 36. Further, the cooling device 30 includes a liquid refrigerant circulation pipe 38 whose inlet and outlet are connected to the liquid receiver 32, and transfers heat between the liquid refrigerant flowing through the refrigerant pipe 36 and the liquid refrigerant flowing through the circulation pipe 38. A Peltier element 40 is provided for this purpose. The refrigerant pipe 36 is composed of a pipe between the liquid receiver 32 and the liquid pump 34, one end of which is connected to the bottom surface of the liquid receiver 32 and descends toward the liquid pump 34. In one embodiment, as shown in FIG. 1, they are arranged in the vertical direction. The Peltier element 40 is provided in this descending pipe. In one embodiment, as shown in FIG. 1, the upper end of the circulation pipe 38 is connected to the liquid receiver 32, descends downward from the bottom surface of the liquid receiver 32, folds upward from the lower end portion, and connects to the bottom surface of the liquid receiver 32. It is configured to do.

FIG. 2 is an enlarged front view showing the Peltier element 40 and its periphery, and FIG. 3 is a partially cut sectional view taken along the line AA in FIG. The Peltier element 40 has an endothermic surface 40a provided on the refrigerant pipe 36 side and a heat radiating surface 40b provided on the circulation pipe 38 side. The saturated liquid refrigerant Lr in the liquid receiver 32 is supplied to the refrigerant pipe 36 and the circulation pipe 38, but when a current is passed through the Peltier element 40 via the lead wire 42, a temperature difference is generated between the heat absorbing surface 40a and the heat radiating surface 40b. Heat transfer occurs from the saturated liquid refrigerant Lr flowing through the refrigerant pipe 36 to the saturated liquid refrigerant Lr flowing through the circulation pipe 38. As a result, the saturated liquid refrigerant Lr flowing through the refrigerant pipe 36 is supercooled, and at least a part of the saturated liquid refrigerant Lr flowing through the circulation pipe 38 is changed to the gas phase by receiving heat. By supercooling the liquid refrigerant flowing through the refrigerant pipe 36, the pressure at which the liquid refrigerant vaporizes can be reduced. As a result, the net positive suction head (NPSHA) can be made larger than the required suction head (NPSHR) on the suction side of the liquid pump 34 provided in the refrigerant pipe 36, so that the restriction for securing the effective suction head can be relaxed. As a result, it is possible to suppress the occurrence of cavitation inside the liquid pump 34 and the suction side piping of the liquid pump 34. Therefore, the cooling device 30 can be made compact and can be operated stably. Further, in order to secure the effective suction head, it is not necessary to newly install a refrigerator, a heat exchanger, etc., and it is only necessary to additionally install a circulation pipe 38, a Peltier element 40, etc., which increases the installation space of the device and increases the installation space of the device. The increase in equipment cost can also be suppressed.

Further, as the temperature difference between the endothermic surface 40a and the heat radiating surface 40b of the Peltier element 40 is smaller, a larger amount of heat absorption can be obtained with less electric power, and the endothermic characteristics are improved. Since the saturated liquid refrigerant Lr flowing down the refrigerant pipe 36 and the saturated liquid refrigerant Lr flowing down the circulation pipe 38 are supplied from the same liquid receiver 32, the temperature difference between the two saturated liquid refrigerants Lr is small. Therefore, the Peltier element 40 can obtain good endothermic characteristics. Further, the saturated liquid refrigerant Lr flowing through the circulation pipe 38 can maintain good endothermic characteristics because only a part of the liquid refrigerant evaporates during heat absorption and changes to the gas phase without changing the temperature of the liquid refrigerant.

FIG. 4 shows a part of the Moriel diagram. In the figure, the point Pc indicates a critical point, the line X on the left side of the point Pc indicates a saturated liquid line, and the line Y on the right side of the point Pc indicates a saturated vapor line. Further, the point a indicates the state amount of the saturated liquid refrigerant in the liquid receiver 32 (for example, −40 ° C., 1.0 MPa), and the point c indicates the state amount of the minimum static pressure portion in the liquid pump 34. The liquid refrigerant supplied from the liquid receiver 32 to the refrigerant pipe 36 is supercooled from the point a by the Peltier element 40 to reach the state amount shown at the point b. In one embodiment, the position on the saturated liquid line X corresponding to the temperature of the supercooled point b is the point d. In this case, the pressure Ps at the point d drops below the pressure at the point c on the saturated liquid line X. Therefore, the net positive suction head (NPSHA, for example, 0.8 m) from the point a to the point d is secured with respect to the required suction head (NPSHR) from the point a to the point c (the minimum static pressure in the liquid pump 34). Since the amount is in a positive state, when the liquid refrigerant flows into the liquid pump 34, it is possible to suppress the occurrence of cavitation inside the liquid pump 34 and the suction side piping of the liquid pump 34.

In one embodiment, as shown in FIG. 1, the circulation pipe 38 is connected to the descending pipe portion 38a via a descending pipe portion 38a extending downward from the liquid receiver 32 and a folded-back portion 38c, and the upper liquid receiver is connected. It has an ascending tube portion 38b extending toward 32. The heat radiating surface 40b of the Peltier element 40 is provided on the rising pipe portion 38b side. In the riser pipe portion 38b, a part of the saturated liquid refrigerant Lr that has received heat from the heat radiating surface 40b is vaporized, and the vaporized gas refrigerant rises due to buoyancy. Therefore, a density difference occurs between the descending pipe portion 38a and the saturated liquid refrigerant Lr that descends due to its own weight, and the flow of natural circulation of liquid receiver 32 → descending pipe portion 38a → folded portion 38c → rising pipe portion 38b → liquid receiver 32. Is formed. Therefore, the power for circulating the refrigerant inside the circulation pipe 38 becomes unnecessary.

Further, FIG. 1 shows an embodiment when the cooling device 30 is incorporated in the refrigeration system 10. In the embodiment shown in FIG. 1, the liquid refrigerant stored in the liquid receiver 32 is a secondary refrigerant, and is a refrigerant. The pipe 36 constitutes a part of the secondary refrigerant circuit 14.

In one embodiment, the cooling load 18 is provided in a refrigerator 44 (for example, a refrigerator, a freezer, etc.) that keeps food or the like in a cold state, and is composed of an air cooler for cooling the inside of the refrigerator 44, and is a secondary refrigerant. The circuit 14 is guided to the air cooler. Therefore, in this embodiment, when the secondary refrigerant is supplied to the air cooler provided in the refrigerator 44, the occurrence of cavitation in the liquid pump 34 and the suction side piping of the liquid pump 34 can be suppressed, so that the secondary refrigerant is supplied to the air cooler. A stable supply of refrigerant can be achieved.

In one embodiment, as shown in FIGS. 2 and 3, a heat transfer promoting member 46 is provided in at least one of the refrigerant pipe 36 and the circulation pipe 38. The heat transfer promoting member 46 is provided in a region that overlaps the heat absorbing surface 40a or the heat radiating surface 40b when viewed from the direction of the normal line N of the heat absorbing surface 40a or the heat radiating surface 40b. By providing the heat transfer promoting member 46, heat transfer with the saturated liquid refrigerant Lr flowing through the refrigerant pipe 36 or the circulation pipe 38 can be promoted, so that heat transfer from the heat absorbing surface 40a side to the heat radiating surface 40b side can be promoted, and the refrigerant can be promoted. The cooling effect of the saturated liquid refrigerant Lr flowing through the pipe 36 by the Peltier element 40 can be improved.

In the exemplary embodiment shown in FIGS. 2 and 3, the heat transfer promoting member 46 is provided on both the refrigerant pipe 36 and the circulation pipe 38. Further, the endothermic surface 40a and the heat radiating surface 40b overlap each other in the entire region in the pipe axis direction of the refrigerant pipe 36 and the circulation pipe 38, and heat transfer is promoted to the entire region of the overlapping refrigerant pipe 36 and the circulation pipe 38. A member 46 is provided. As a result, heat transfer is promoted in the entire overlapping region, so that the cooling effect of the saturated liquid refrigerant Lr by the Peltier element 40 can be improved.

When the pressure loss of the liquid refrigerant flowing through the refrigerant pipe 36 becomes large due to the arrangement of the heat transfer promoting member 46, it is necessary to secure an extra effective suction head by the amount of the pressure loss, so that the pressure loss needs to be suppressed as much as possible. Further, since heat transfer can be promoted by increasing the heat transfer area of the heat transfer promoting member 46, the heat transfer promoting member 46 is preferably made of a material having a large surface area.

In one embodiment, as shown in FIGS. 5 and 6, the heat transfer promoting member 46 is made of a porous material having a large surface area. This promotes heat transfer between the piping and the liquid refrigerant through the porous material. Further, since the liquid refrigerant becomes a turbulent flow due to the turbulent flow promoting effect of the porous material, it is possible to enhance the heat transfer between the piping and the liquid refrigerant while suppressing the pressure loss of the liquid refrigerant. In the porous material 46 (46a) shown in FIG. 5, a void 47 having a pore diameter of about 0.8 mm is formed in a cell having a diameter of about 2.4 mm.

The porous material 46 (46b) shown in FIG. 6 is composed of an aggregate of linear members. Since the heat transfer promoting member 46 is composed of an aggregate of such linear members, the surface area can be increased, and the refrigerant pipe 36 and the circulation pipe can be suppressed while suppressing the pressure loss of the liquid refrigerant flowing through the refrigerant pipe 36 or the circulation pipe 38. The heat transfer of the liquid refrigerant flowing through 38 can be promoted, and the cooling effect of the liquid refrigerant can be enhanced.

In one embodiment, the heat transfer promoting member 46 is made of a porous material made of a metal material having good thermal conductivity, such as copper or aluminum. As a result, the heat transfer effect of the heat transfer promoting member 46 can be further enhanced, and the cooling effect of the liquid refrigerant flowing through the refrigerant pipe 36 can be further enhanced.

In one embodiment, the Peltier element 40 is configured to have a cooling performance capable of cooling the saturated liquid refrigerant Lr flowing through the refrigerant pipe 36 to a supercooling temperature corresponding to the required suction head of the liquid pump 34 or higher. As a result, the saturated liquid refrigerant Lr flowing through the refrigerant pipe can be lowered to a boiling point pressure higher than the required suction head of the liquid pump 34 by the Perche element 40, so that the liquid pump 34 and the liquid pump 34 do not need to form the required suction head in the refrigerant pipe 36. Occurrence of cavitation can be reliably suppressed inside the suction side pipe of the liquid pump 34.

In one embodiment, as shown in FIG. 1, a pressure sensor 48 for detecting the pressure of the gas phase portion in the liquid receiver 32, a temperature sensor 49 for detecting the temperature of the liquid refrigerant on the inlet side of the liquid pump 34, and a pressure. A control unit 50 that controls the operation of the Pelche element 40 based on the detected values of the sensor 48 and the temperature sensor 49 is provided. According to this embodiment, the control unit 50 controls the operation of the Peltier element 40 based on the detected value of the pressure sensor 48, and the control unit 50 feedback-controls the Peltier element based on the detected value of the temperature sensor 49. Therefore, the degree of supercooling of the liquid refrigerant near the inlet of the liquid pump 34 can be accurately controlled to be equal to or higher than the required suction head.
In the embodiment shown in FIG. 1, the control unit 50 controls the power supply unit 41 and controls the current value to be passed through the Peltier element 40 via the conducting wire 42.

Hereinafter, an example of specific control by the control unit 50 will be described. First, the temperature Tb at the point b is detected by the temperature sensor 49. Next, the pressure Pa in the liquid receiver 32 is detected by the pressure sensor 48. From the pressure Pa and the temperature Tb at the point b, the enthalpy hb at the point b is calculated using the following known formula.
hb = f (Pa, Tb)
Further, the pressure Ps at the point d that becomes the enthalpy hb on the saturated liquid line X is calculated using the following known formula.
hd = f (Ps) hd = hb
The net positive suction head (NPSHA) ΔP can be obtained from ΔP = Pa−Ps. The net positive suction head (NPSHA) H of the liquid refrigerant actually used is calculated by the following formula.
H = ΔP / ρd ・ g
Here, ρd is the density of the liquid refrigerant at the point d, and g is gravity.
ρd can be obtained from the pressure Ps by the known formula ρd = f (Ps). The current value supplied to the Peltier element 40 is controlled so that the head H of the liquid refrigerant used is larger than the required suction head (NPSHR). As a result, even if the amount of cooling heat of the cooling load 18 fluctuates and the temperature and pressure in the liquid receiver 42 fluctuate, cavitation can be reliably suppressed inside the liquid pump 34 and its suction side piping.

In one embodiment, as shown in FIG. 1, the refrigerant pipe 36 and the circulation pipe 38 are arranged parallel to each other at least in the installation area where the Peltier element 40 is installed. Then, the Peltier element 40 extends between the refrigerant pipe 36 and the circulation pipe 38 along the pipe axis direction of the refrigerant pipe 36 and the circulation pipe 38. Since the refrigerant pipe 36, the circulation pipe 38, and the Peltier element 40 extend along the same direction in this way, the arrangement space of the Peltier element 40 between the endothermic surface 40a and the heat radiating surface 40b can be reduced, and the Peltier element 40 can be reduced. Easy to place. Further, since the wide endothermic surface 40a and the heat radiating surface 40b can be easily secured, the efficiency of the Peltier element 40 can be improved, and the cooling effect of the liquid refrigerant flowing through the refrigerant pipe 36 can be enhanced.

In the embodiment shown in FIGS. 2 and 3, the main body of the Peltier element 40 is formed in a plate shape. By forming the Peltier element 40 in a plate shape in this way, the Peltier element 40 can be easily arranged even if the space between the refrigerant pipe 36 and the circulation pipe 38 is narrow.

In one embodiment, as shown in FIGS. 2, 3 and 7, 8, the first block 52 (52a, 52b) and the second block 62 (62a, 62b) are provided so as to sandwich the Peltier element 40. There is. The first block 52 has a first through hole 54 through which the refrigerant pipe 36 penetrates and a first heat transfer surface 56 that abuts on the endothermic surface 40a, and is provided around the refrigerant pipe 36. The second block 62 has a second through hole 64 through which the circulation pipe 38 penetrates and a second heat transfer surface 66 in contact with the heat radiation surface 40b, and is provided around the circulation pipe 38. Since the first block 52 and the second block 62 are provided, the heat absorbing surface 40a and the heat radiating surface 40b can be easily formed.

In the exemplary embodiment shown in FIGS. 2, 3 and 7, 8, the second block 62 is provided around the riser pipe portion 38b of the circulation pipe 38. As a result, as described above, a natural circulating flow of the saturated liquid refrigerant Lr can be formed in the circulation pipe 38.

In one embodiment, as shown in FIGS. 2 and 3, the endothermic surface 40a and the heat radiating surface 40b are arranged parallel to each other along the pipe axis direction of the refrigerant pipe 36 and the circulation pipe 38, and the first block 52 (52a). ) Or at least one of the second blocks 62 (62a) is two or more divided pieces 53a, 53b or divided along the first divided surface 55a or the second divided surface 65a along the endothermic surface 40a or the heat radiating surface 40b. It is composed of 63a and 63b. Each of the split pieces 53a and 53b has a recess forming the first through hole 54, and at least one of the split pieces 53a and 53b has an endothermic surface 40a. Further, each of the divided pieces 63a and 63b has a recess forming the second through hole 64, and at least one of the divided pieces 63a and 63b has a heat radiating surface 40b. As described above, since the first block 52 (52a) or the second block 62 (62a) is composed of two or more divided pieces, the refrigerant of the first block 52 (52a) or the second block 62 (62a) It becomes easy to attach to the pipe 36 or the circulation pipe 38.

In the exemplary embodiment shown in FIGS. 2 and 3, the second block 62 (62a) is provided around the riser tube portion 38b of the circulation tube 38. As a result, as described above, a natural circulating flow of the saturated liquid refrigerant Lr can be formed in the circulation pipe 38.

In the exemplary embodiment shown in FIGS. 2 and 3, in the first block 52 (52a), the surface along the endothermic surface 40a is the first dividing surface 55a, and the first block 52 (52a) is divided along the first dividing surface 55a. It is composed of divided pieces 53a and 53b. Further, the second block 62 (62a) is composed of two divided pieces 63a and 63b divided along the second divided surface 65a, with the surface along the heat radiating surface 40b as the second divided surface 65a.

In the exemplary embodiment shown in FIGS. 2 and 3, the first block 52 (52a) and the second block 62 (62a) are formed in the shape of a rectangular parallelepiped. As a result, the area of the first heat transfer surface 56 and the second heat transfer surface 66 can be increased. Further, the first block 52 (52a) is composed of two divided pieces 53a and 53b divided in half along the first dividing surface 55a, and each has a semicircular recess. By arranging the divided pieces 53a and 53b so as to sandwich the refrigerant pipe 36 in the recess, the first block 52 (52a) can be easily arranged around the refrigerant pipe 36. Similarly, the second block 62 (62a) is composed of two divided pieces 63a and 63b divided in half along the second dividing surface 65a, and each has a recess having a semicircular cross section. By arranging the divided pieces 63a and 63b so as to sandwich the rising pipe portion 38b of the circulation pipe 38 in the recess, the second block 62 (62a) can be easily arranged around the rising pipe portion 38b of the circulation pipe 38.

In the exemplary embodiment shown in FIGS. 2 and 3, the divided pieces 53a and 53b and the divided pieces 63a and 63b are in contact with each other on the first divided surface 55a or the second divided surface 65a, respectively. In the state, they are joined by bolts 70 arranged so as to extend along the direction of the normal N.

In one embodiment, as shown in FIGS. 7 and 8, the endothermic surface 40a and the heat radiating surface 40b are arranged parallel to each other along the pipe axis direction of the refrigerant pipe 36 and the circulation pipe 38, and the first block 52 (52b). ) Or the second block 62 (62b) includes the pipe shafts of the refrigerant pipe 36 and the circulation pipe 38, and is along the surface intersecting the endothermic surface 40a and the heat radiating surface 40b. It is composed of two or more divided pieces 53c, 53d or 63c, 63d divided by. Each of the split pieces 53c and 53d has a recess forming the first through hole 54, and at least one of the split pieces 53c and 53d has an endothermic surface 40a. Further, each of the divided pieces 63c and 63d has a recess forming the second through hole 64, and at least one of the divided pieces 63c and 63d has a heat radiating surface 40b.

As described above, since the first block 52 (52b) or the second block 62 (62b) is composed of two or more divided pieces, the refrigerant of the first block 52 (52b) or the second block 62 (62b) It becomes easy to attach to the pipe 36 or the circulation pipe 38. Further, the two or more divided pieces are divided along the surfaces intersecting the endothermic surface 40a and the heat radiating surface 40b including the pipe shafts of the refrigerant pipe 36 and the circulation pipe 38, and these divided surfaces are the endothermic surface 40a and the heat radiating surface. Since it is arranged in a direction that does not block the heat transfer generated along the direction intersecting with 40b and does not become a heat transfer resistance, the heat transfer performance can be improved.

In the exemplary embodiment shown in FIGS. 7 and 8, the second block 62 (62b) is provided around the riser tube portion 38b of the circulation tube 38. As a result, as described above, a natural circulating flow of the saturated liquid refrigerant Lr can be formed in the circulation pipe 38.

In the exemplary embodiment shown in FIGS. 7 and 8, the first block 52 (52b) and the second block 62 (62b) are surfaces that include the shafts of the refrigerant pipe 36 and the circulation pipe 38 and include the normal N. Is a first division surface 55b or a second division surface 65b, and is composed of two division pieces 53c, 53d and 63c, 63d divided along the first division surface 55b or the second division surface 65b. As a result, the first dividing surface 55b or the second dividing surface 65b is arranged in a direction that does not block the heat transfer generated along the direction orthogonal to the endothermic surface 40a and the heat radiating surface 40b, and does not become a heat transfer resistance. Performance can be improved.

In the exemplary embodiment shown in FIGS. 7 and 8, the first block 52 (52b) and the second block 62 (62b) are formed in the shape of a rectangular parallelepiped. As a result, the area of the first heat transfer surface 56 and the second heat transfer surface 66 can be increased. Further, the first block 52 (52b) is composed of two divided pieces 53c and 53d divided in half along the first dividing surface 55b, and each has a semicircular recess. By arranging the divided pieces 53c and 53d so as to sandwich the refrigerant pipe 36 in the recess, the first block 52 (52b) can be easily arranged around the refrigerant pipe 36. Similarly, the second block 62 (62b) is composed of two divided pieces 63c and 63d divided in half along the second dividing surface 65b, each of which is formed with a recess having a semicircular cross section. By arranging the divided pieces 63c and 63d so as to sandwich the rising pipe portion 38b of the circulation pipe 38 in the recess, the second block 62 (62b) can be easily arranged around the rising pipe portion 38b of the circulation pipe 38.

In the exemplary embodiment shown in FIGS. 7 and 8, the divided pieces 53c and 53d and the divided pieces 63c and 63d are in contact with each other on the first divided surface 55b or the second divided surface 65b, respectively. In the state, they are connected by bolts 71 arranged so as to extend along the direction orthogonal to the pipe axis direction and the direction of the normal N.

As yet another embodiment, the first block 52 (52a) shown in FIGS. 2 and 3 and the second block 62 (62b) shown in FIGS. 7 and 8 can be used in combination. Further, the second block 62 (62a) shown in FIGS. 2 and 3 and the first block 52 (52b) shown in FIGS. 7 and 8 can be used in combination.

Further, in the exemplary embodiment shown in FIGS. 2 and 3, the connecting plate 58a having two sides larger than the two vertical and horizontal sides of the first block 52 (52a) on the endothermic surface 40a side of the first block 52 (52a) is formed. It is integrally formed with the first block 52 (52a). Further, a connecting plate 68a having two sides larger than the two vertical and horizontal sides of the second block 62 (62a) is integrally formed with the second block 62 (62a) on the heat radiating surface 40b side of the second block 62 (62a). .. In the exemplary embodiment shown in FIGS. 7 and 8, the coupling plate 58b having a side whose side along the direction orthogonal to the pipe axis direction of the refrigerant pipe 36 is larger than the side of the first block 52 (52b) is the first block. The second coupling plate 68b is provided integrally with the 52 (52b) and has a side having a side larger than the side of the second block 62 (62b) along a direction orthogonal to the pipe axis direction of the rising pipe portion 38b of the circulation pipe 38. It is provided integrally with the block 62 (62b). Since the coupling plates 58a, 58b and 68a, 68b are provided in this way, it is possible to form a wide heat absorbing surface 40a, a heat radiating surface 40b, a first heat transfer surface 56, and a second heat transfer surface 66.

In the exemplary embodiments shown in FIGS. 2, 3 and 7 and 8, bolt holes are formed in the coupling plates 58a, 58b and 68a, 68b, and the coupling plates 58a, 58b and 68a, 58b are bolted 72 and nuts 74. By coupling with, the coupling plates 58a, 58b and 68a, 68b can be easily fixed to both side surfaces of the Peltier element 40.

In one embodiment, as shown in FIGS. 7 and 8, the heat transfer promoting member 46 is provided in both the refrigerant pipe 36 and the circulation pipe 38. Then, in the tube axis direction of the refrigerant pipe 36 or the circulation pipe 38, the first region L ₁ of the circulation pipe 38 is heat transfer enhancing members 46 are provided, the refrigerant pipe 36 is heat transfer enhancing members 46 provided 2 it is a broad than the area _{L 2.} The pressure loss of the saturated liquid refrigerant Lr generated in the refrigerant pipe 36 cancels out the reduction in the boiling point pressure reduced by the overcooling by the Perche element 40, and cavitation is likely to occur in the liquid pump 34. Therefore, by setting the second region L ₂ <the first region L ₁ , the pressure loss of the saturated liquid refrigerant Lr flowing through the refrigerant pipe 36 can be reduced. On the other hand, the refrigerant flowing through the circulation pipe 38 is heated by the heat radiating surface 40b and is in the boiling region, and the flow velocity is slow because it is an upward flow. Therefore, the pressure loss does not increase. Therefore, heat transfer can be promoted by expanding the second region L _{2 along the pipe axis direction.}

In the exemplary embodiment shown in FIG. 7, the endothermic surface 40a and the heat radiating surface 40b overlap each other in the entire region in the pipe axis direction, and the second region L of the heat transfer promoting member 46 filled in the refrigerant pipe 36. ₂ is a narrower range than the overlap region, the first region L ₁ of the circulation pipe 38 rising pipe section 38b is filled in the heat transfer promoting member 46 is wide than the overlap area. As a result, the pressure loss can be reduced in the refrigerant pipe 36, and heat transfer can be promoted in the circulation pipe 38.

In one embodiment, between the refrigerant pipe 36 and the wall surface of the first block 52 forming the first through hole 54, between the endothermic surface 40a and the first heat transfer surface 56, the circulation pipe 38 and the second through hole 64. At least one place between the wall surface of the second block 62 and between the heat radiating surface 40b and the second heat transfer surface 66 is filled with heat transfer grease. As a result, heat transfer from the refrigerant pipe 36 to the circulation pipe 38 via the endothermic surface 40a and the heat radiating surface 40b can be further promoted.

In the embodiment shown in FIGS. 2 and 3, the first divided surface 55a or the second divided surface 65a can be filled with heat-transmitting grease. Thereby, heat transfer between the divided pieces 53a and 53b and between the divided pieces 63a and 63b can be promoted. Further, in the embodiment shown in FIGS. 7 and 8, the first divided surface 55b or the second divided surface 65b can be filled with heat-transmitting grease. Thereby, heat transfer between the divided pieces 53c and 53d and between the divided pieces 63c and 63d can be promoted.
In the embodiment shown in FIGS. 7 and 8, since the first dividing surface 55b and the second dividing surface 65b are formed in the direction along the normal line N, the first dividing surface 55b and the second dividing surface 65b are formed. Since the heat transfer from the endothermic surface 40a to the refrigerant pipe 36 side and the heat transfer from the heat dissipation surface 40b to the circulation pipe 38 side are not hindered, there is an advantage that the heat transfer performance can be improved.

9 and 10 show experimental data in which the heat transfer coefficient was obtained by flowing a liquid refrigerant (carbon dioxide liquid) having a temperature of −20 ° C. through the refrigerant pipe 36 and the circulation pipe 38 in the cooling device 30 shown in FIGS. 2 and 3. Is shown. In FIGS. 9 and 10, black circles are cases where the aluminum porous material shown in FIG. 6 is filled in the refrigerant pipe 36 and the circulation pipe 38, and white circles are cases where the refrigerant pipe 36 and the circulation pipe 38 are filled with the porous material. Is not filled. The horizontal axis of FIG. 9 shows the Reynolds number Re, which is an index showing the flow rate of the liquid refrigerant, and the horizontal axis of FIG. 10 shows the heat flux. From FIG. 9, it was found that the heat transfer coefficient obtained when the porous material was filled increased by about four times the heat transfer coefficient when the porous material was not filled. Further, from FIG. 10, it was found that the heat transfer coefficient obtained when the porous material was filled increased by about 1.5 times the heat transfer coefficient when the porous material was not filled.

In one embodiment, the control unit 50 reduces the current value flowing through the Peltier element 40 when the load of the refrigeration system 10 increases, and increases the current value flowing through the Peltier element 40 when the load of the refrigeration system 10 decreases. It is configured to let you. That is, when the load of the refrigeration system 10 increases, the pressure in the liquid receiver 32 also increases, so that the required effective suction head decreases. Therefore, even if the value of the current flowing through the Peltier element 40 is reduced and the degree of supercooling of the liquid refrigerant is reduced, the occurrence of cavitation can be suppressed inside the liquid pump 34 and the suction side piping of the liquid pump 34. On the contrary, when the load of the refrigeration system 10 is reduced, the pressure in the liquid receiver 32 is also reduced, so that the required effective suction head is increased. Therefore, by increasing the value of the current flowing through the Peltier element 40 and increasing the degree of supercooling of the liquid refrigerant, it is possible to suppress the occurrence of cavitation inside the liquid pump 34 and the suction side piping of the liquid pump 34.

The contents described in each of the above embodiments are grasped as follows, for example.

1) The cooling device (30) according to one embodiment includes a liquid receiver (32), a liquid pump (34) for sending the liquid refrigerant in the liquid receiver (32) to a cooling load, and the liquid receiver (32). ) And the liquid pump (34), the liquid refrigerant circulation pipe (38) whose inlet and outlet are connected to the liquid receiver (32), and the refrigerant pipe. A Perche element (40) having a heat absorbing surface (40a) provided on the (36) side and a heat radiating surface (40b) provided on the circulation pipe (38) side is provided.

According to such a configuration, the Pelche element causes heat transfer from the liquid refrigerant flowing through the refrigerant pipe to the liquid refrigerant flowing through the circulation pipe, and the liquid refrigerant is overcooled on the suction side of the liquid pump, so that the liquid refrigerant becomes The vaporizing pressure can be reduced. As a result, it is possible to suppress the occurrence of cavitation inside the liquid pump and the suction side piping, so that the restrictions for securing the net positive suction head can be relaxed, and the cooling device can be made compact and stable operation becomes possible. Further, unlike Patent Documents 1 and 2, since it is not necessary to newly install a refrigerator, a heat exchanger, etc., it is possible to suppress an increase in the installation space of the device and an increase in the device cost. Further, the smaller the temperature difference between the endothermic surface and the heat radiating surface of the Pelche element, the better the endothermic characteristics. However, the endothermic side liquid refrigerant and the heat radiating side liquid refrigerant are supplied from the same liquid receiver, and the temperatures of both liquid refrigerants are supplied. Since the difference is small, good endothermic properties can be obtained. Further, since the liquid refrigerant on the heat dissipation side undergoes a phase change during heat absorption and does not involve a temperature change, good endothermic characteristics can be maintained.

2) The cooling device according to another aspect is the cooling device according to 1), in which the Peltier element (40) is formed in at least one of the refrigerant pipe (36) and the circulation pipe (38). When viewed from the direction of the normal line (N) of the heat absorbing surface (40a) or the heat radiating surface (40b), it overlaps with the heat absorbing surface (40a) or the heat radiating surface (40b) of the pipes (36, 38). A heat transfer promoting member (46) provided in the area to be wrapped is provided.

According to such a configuration, the heat transfer promoting member provided inside the refrigerant pipe or the circulation pipe can promote the heat transfer between the refrigerant pipe or the circulation pipe and the liquid refrigerant flowing through these pipes, so that the heat absorption surface side can be promoted. It is possible to promote heat transfer from the water to the heat radiation surface side, thereby enhancing the cooling effect of the liquid refrigerant flowing through the refrigerant pipe.

3) The cooling device according to still another aspect is the cooling device according to 2), and the heat transfer promoting member (46) is made of a porous material (46 (46a, 46b)).

According to such a configuration, the porous material having a large surface area promotes heat transfer between the pipe wall surface and the liquid refrigerant through the porous material. Further, the turbulent flow promoting effect of the porous material causes the liquid refrigerant to become turbulent, so that the heat transfer between the piping and the liquid refrigerant can be enhanced while suppressing the pressure loss of the liquid refrigerant.

4) The cooling device according to still another aspect is the cooling device according to 2) or 3), and the heat transfer promoting member (46) is the cooling device of the refrigerant pipe (36) and the circulation pipe (38). _{A first region (L 1} ) of the circulation pipe (38) provided inside and provided with the heat transfer promoting member (46) in the pipe axial direction of the refrigerant pipe (36) or the circulation pipe (38). Is wider than _{the second region (L 2} ) of the refrigerant pipe (36) provided with the heat transfer promoting member (46).

The pressure loss of the saturated liquid refrigerant generated in the refrigerant pipe cancels out the reduction in boiling pressure (pressure at which the liquid refrigerant evaporates) reduced by overcooling by the Pelche element, and cavitation occurs on the suction side of the liquid pump. It will be easier. According to the above configuration, the pressure loss of the saturated liquid refrigerant flowing through the refrigerant pipe can be reduced by setting the first region of the refrigerant pipe filled with the heat transfer promoting member to a narrow range. On the other hand, the refrigerant flowing through the circulation pipe is heated and is in the boiling region and is an upward flow, so the flow velocity is also slow. Therefore, since the pressure loss does not increase, heat transfer can be promoted by expanding the second region.

5) The cooling device according to still another aspect is the cooling device according to any one of 1) to 4), and the circulation pipe (38) descends downward from the liquid receiver (32). A pipe portion (38a) and an ascending pipe portion (38b) connected to the descending pipe portion (38a) via a folded portion (38c) and extending upward to the liquid receiver (32) are included. The heat radiating surface (40b) of the Peltier element (40) is provided on the rising pipe portion (38b) side.

According to such a configuration, in the riser pipe portion, a part of the saturated liquid refrigerant that receives heat from the heat radiating surface is vaporized, and the vaporized gas refrigerant rises due to buoyancy. Therefore, the descending pipe portion is lowered by its own weight, and the natural circulation of the refrigerant that rises in the rising pipe portion occurs. Therefore, the power for circulating the refrigerant inside the circulation pipe becomes unnecessary.

6) The cooling device according to still another aspect is the cooling device according to any one of 1) to 5), wherein the Perche element (40) is the liquid refrigerant (Lr) flowing through the refrigerant pipe (36). ) Is configured to be able to be cooled to a supercooling temperature corresponding to the required suction head (NPSHR) of the liquid pump (34).

According to such a configuration, the liquid refrigerant flowing through the refrigerant pipe can be lowered to a boiling point pressure higher than the required suction head of the liquid pump by the Perche element, so that the liquid pump or the liquid can be used without forming the necessary suction head in the refrigerant pipe. It is possible to suppress the occurrence of cavitation inside the suction side pipe of the pump.

7) The cooling device according to still another aspect is the cooling device according to any one of 1) to 6), the pressure sensor (48) for detecting the pressure in the liquid receiver (32), and the liquid. The Perche element (40) is controlled based on the temperature sensor (49) that detects the temperature of the liquid refrigerant on the inlet side of the pump (34) and the detection values of the pressure sensor (48) and the temperature sensor (49). A control unit (50) is provided.

According to such a configuration, the control unit controls the operation of the Peltier element based on the detection value of the pressure sensor, and feedback controls the Peltier element based on the detection value of the temperature sensor. As a result, even if the cooling load fluctuates and the pressure or temperature in the liquid receiver fluctuates, the occurrence of cavitation inside the liquid pump or the suction side piping of the liquid pump can be reliably suppressed.

8) The cooling device according to still another aspect is the cooling device according to any one of 1) to 7), and the refrigerant pipe (36) and the circulation pipe (38) are at least the Peltier element. In the installation area where (40) is installed, the Peltier element (40) is arranged parallel to each other, and the Peltier element (40) is placed between the refrigerant pipe (36) and the circulation pipe (38). It extends along the pipe axis direction of the circulation pipe (38).

According to such a configuration, since the refrigerant pipe, the circulation pipe and the Peltier element extend along the same direction, the space for arranging the Peltier element between the refrigerant pipe and the circulation pipe can be reduced, and the Peltier element can be arranged. It will be easier. Further, since a wide heat absorbing surface and heat radiating surface can be easily secured, the efficiency of the Peltier element can be improved.

9) The cooling device according to still another aspect is the cooling device according to any one of 1) to 8), in the first through hole (54) through which the refrigerant pipe penetrates and the heat absorbing surface (40a). A first block (52) having a first heat transfer surface (56) that comes into contact with the refrigerant pipe (36) and a second through hole (64) through which the circulation pipe (38) penetrates. A second heat transfer surface (66) that abuts on the heat radiation surface (40b) and is provided around the circulation tube at a position facing the first block with the Peltier element (40) interposed therebetween. It includes two blocks (62).

According to such a configuration, since the first block and the second block of the above configuration are provided, the arrangement of the Peltier element and the formation of the endothermic surface and the heat radiating surface become easy.

10) The cooling device according to still another aspect is the cooling device according to 9), and the endothermic surface (40a) and the heat radiating surface (40b) are the refrigerant pipe (36) and the circulation pipe (38). ) Are arranged parallel to each other along the pipe axis direction, and at least one of the first block (52) or the second block (62) is along the endothermic surface (40a) or the heat radiating surface (40b). It is composed of two or more divided pieces (53a, 53b, 63a, 63b), and each of the divided pieces is a recess forming the first through hole (54) or the second through hole (64). At least one of the divided pieces has the endothermic surface (40a) or the heat radiating surface (40b).

According to such a configuration, since the first block or the second block is composed of two or more divided pieces, the first block or the second block can be easily attached to the refrigerant pipe or the circulation pipe.

11) The cooling device according to still another aspect is the cooling device according to 9), and the endothermic surface (40a) and the heat radiating surface (40b) are the refrigerant pipe (36) and the circulation pipe (38). ) Are arranged parallel to each other along the pipe axis direction, and at least one of the first block (52) or the second block (62) is a pipe shaft of the refrigerant pipe (36) and the circulation pipe (38). It is composed of two or more divided pieces (53c, 53d, 63c, 63d) divided along a surface intersecting the endothermic surface (40a) and the heat radiating surface (40b), and each of the divided pieces The first through hole (54) or the second through hole (64) is formed, and at least one of the divided pieces has the endothermic surface (40a) or the heat radiation surface (40b). ..

According to such a configuration, since the first block or the second block is composed of two or more divided pieces, the first block or the second block can be easily attached to the refrigerant pipe or the circulation pipe. Further, the two or more divided pieces are divided along a surface that includes the tube shafts of the refrigerant pipe and the circulation pipe and intersects the endothermic surface and the heat radiating surface, and the divided surfaces are arranged in a direction that does not block heat transfer to transfer heat. Since it does not become a resistance, it is possible to improve the heat transfer performance from the endothermic surface to the refrigerant pipe and the heat transfer performance from the heat dissipation surface to the circulation pipe.

12) The cooling device according to still another aspect is the cooling device according to any one of 9) to 11), wherein the first through hole (54) is formed with the refrigerant pipe (36). The first to form the circulation tube (38) and the second through hole (64) between the wall surface of the block (52), the heat absorbing surface (40a) and the first heat transfer surface (56). At least one place between the wall surface of the two blocks (62) and between the heat radiation surface (40b) and the second heat transfer surface (66) is filled with heat transfer grease.

According to such a configuration, since the heat transferable grease is filled in the above-mentioned portion, heat transfer from the refrigerant pipe to the circulation pipe through the heat absorbing surface and the heat radiating surface can be further promoted.

13) The cooling system (10) according to the present disclosure includes a primary refrigerant circuit (12) in which the primary refrigerant circulates, a refrigeration cycle component device including an evaporator (16) provided in the primary refrigerant circuit (12), and a refrigeration cycle component device. The secondary refrigerant circuit (14) for supplying the secondary refrigerant cooled by the primary refrigerant in the evaporator (16) to the cooling load (18) and the secondary refrigerant circuit (14) are provided. The above-mentioned cooling device (30) is provided, the liquid refrigerant is stored in the liquid receiver (32) as the secondary refrigerant, and the refrigerant pipe (36) is the liquid receiver (32) and the liquid pump. It constitutes a part of the secondary refrigerant circuit (14) with (34).

According to such a configuration, the Perche element overcools the liquid refrigerant on the suction side of the liquid pump, so that the boiling pressure can be lowered, which causes cavitation inside the liquid pump and the suction side piping of the liquid pump. Since it can be suppressed from occurring, the restriction for securing the net positive suction head can be relaxed. Therefore, the cooling device can be made compact and stable operation becomes possible. Further, since it is not necessary to newly install a refrigerator, a heat exchanger, or the like, it is possible to suppress an increase in the installation space of the device and the cost of the device.

14) The cooling system according to another aspect is the cooling system according to 13), the cooling load (18) is an air cooler provided in a refrigerator, and the secondary refrigerant circuit (14) is the air cooler. It is guided to.

According to such a configuration, when the secondary refrigerant is supplied to the air cooler provided in the refrigerator, the occurrence of cavitation can be suppressed inside the liquid pump and the suction side piping of the liquid pump, so that the secondary refrigerant is supplied to the air cooler. A stable supply of refrigerant can be achieved.

15) The cooling system according to still another aspect is the cooling system according to 13) or 14), wherein the pressure sensor (48) for detecting the pressure in the liquid receiver (32) and the liquid pump (34). ), A temperature sensor (49) that detects the temperature of the liquid refrigerant on the inlet side, and a control unit that controls the Pelche element (40) based on the detection values of the pressure sensor (48) and the temperature sensor (49). (50), the control unit (50) reduces the current value flowing through the Pelche element (40) when the load of the cooling system increases, and when the load of the cooling system decreases. It is configured to increase the value of the current flowing through the Pelche element (40).

According to such a configuration, even if the load of the cooling system fluctuates, cavitation occurs inside the liquid pump or the suction side piping of the liquid pump by changing the current value flowing through the Peltier element according to the load fluctuation. It can be surely suppressed.

10 Refrigeration system 12 Primary refrigerant circuit 14 Secondary lubricant circuit 16 Evaporator 22 Condenser 18 Cooling load 20 Compressor 24 Expansion valve 30 Cooling device 32 Liquid receiver 34 Liquid pump 36 Coolant pipe 38 Circulation pipe 38a Down pipe 38b Raising pipe 38c Folded part 40 Perche element 40a Heat absorption surface 40b Heat dissipation surface 41 Power supply unit 42 Conductor 44 Cooler 46 Heat transfer promotion member 46 (46a, 46b) Porous material 47 Void 48 Pressure sensor 49 Temperature sensor 50 Control unit 52 (52a, 52b) ) First block 53a, 53b, 53c, 53d, 63a, 63b, 63c, 63d Division piece 54 First through hole 55a, 55b First division surface 56 First heat transfer surface 58a, 58b, 68a, 68b Bonding plate 62 ( 62a, 62b) Second block 64 Second through hole 65a, 65b Second division surface 66 Second heat transfer surface 70, 71, 72 Bolt 74 Nut X Saturated liquid line Y Saturated steam line L ₁ First area L ₂ Second Region Lr Saturated Liquid Refrigerator N Normal Line NPSHR Required Suction Head NPSHA Net Positive Suction Head Pc Critical Point

Claims (15)

With a liquid receiver
A liquid pump for sending the liquid refrigerant in the liquid receiver to the cooling load,
A refrigerant pipe provided between the liquid receiver and the liquid pump,
A circulation pipe of the liquid refrigerant whose inlet and outlet are connected to the liquid receiver, and
A Peltier element having an endothermic surface provided on the refrigerant pipe side and a heat radiating surface provided on the circulation pipe side.
A cooling device equipped with. In at least one of the refrigerant pipe and the circulation pipe, when viewed from the normal direction of the endothermic surface or the heat radiating surface of the Peltier element, it overlaps with the endothermic surface or the heat radiating surface of the pipe. The cooling device according to claim 1, further comprising a heat transfer promoting member provided in the region. The cooling device according to claim 2, wherein the heat transfer promoting member is made of a porous material. The heat transfer promoting member is provided inside the refrigerant pipe and the circulation pipe.
In the axial direction of the refrigerant pipe or the circulation pipe, the first region of the circulation pipe provided with the heat transfer promoting member is wider than the second region of the refrigerant pipe provided with the heat transfer promoting member. The cooling device according to claim 2 or 3. The circulation pipe includes a descending pipe portion extending downward from the liquid receiver and an ascending pipe portion connected to the descending pipe portion via a folded portion and extending upward to the liquid receiver.
The cooling device according to any one of claims 1 to 4, wherein the heat radiating surface of the Peltier element is provided on the rising pipe portion side. The Peltier element according to any one of claims 1 to 5, wherein the Peltier element is configured to be capable of cooling the liquid refrigerant flowing through the refrigerant pipe to a supercooling temperature corresponding to the required effective suction head of the liquid pump. Cooling system. A pressure sensor that detects the pressure in the liquid receiver and
A temperature sensor that detects the temperature of the liquid refrigerant on the inlet side of the liquid pump, and
A control unit that controls the Peltier element based on the detected values of the pressure sensor and the temperature sensor.
The cooling device according to any one of claims 1 to 6. The refrigerant pipe and the circulation pipe are arranged in parallel with each other at least in the installation area where the Peltier element is installed.
The cooling device according to any one of claims 1 to 7, wherein the Peltier element extends between the refrigerant pipe and the circulation pipe along the pipe axis direction of the refrigerant pipe and the circulation pipe. A first block having a first through hole through which the refrigerant pipe penetrates and a first heat transfer surface in contact with the endothermic surface, and a first block provided around the refrigerant pipe.
It has a second through hole through which the circulation pipe penetrates and a second heat transfer surface that abuts on the heat radiation surface, and is provided around the circulation pipe at a position facing the first block with the Peltier element interposed therebetween. The cooling device according to any one of claims 1 to 8, further comprising a second block. The endothermic surface and the heat radiating surface are arranged parallel to each other along the pipe axis direction of the refrigerant pipe and the circulation pipe.
At least one of the first block or the second block is composed of two or more divided pieces divided along the endothermic surface or the heat radiating surface.
Each of the divided pieces has a recess forming the first through hole or the second through hole.
The cooling device according to claim 9, wherein at least one of the divided pieces has the endothermic surface or the heat radiating surface. The endothermic surface and the heat radiating surface are arranged parallel to each other along the pipe axis direction of the refrigerant pipe and the circulation pipe.
At least one of the first block or the second block is two or more divided pieces divided along a surface intersecting the endothermic surface and the heat radiating surface, including the pipe shafts of the refrigerant pipe and the circulation pipe. Configured,
Each of the divided pieces has a recess forming the first through hole or the second through hole.
The cooling device according to claim 9, wherein at least one of the divided pieces has the endothermic surface or the heat radiating surface. The first through hole is formed between the refrigerant pipe and the wall surface of the first block forming the first through hole, between the endothermic surface and the first heat transfer surface, and the circulation pipe and the second through hole. The invention according to any one of claims 9 to 11, wherein at least one place between the wall surface of the two blocks and the heat radiation surface and the second heat transfer surface is filled with heat transfer grease. Cooling device. The primary refrigerant circuit in which the primary refrigerant circulates,
Refrigerating cycle components including an evaporator provided in the primary refrigerant circuit, and
A secondary refrigerant circuit for supplying the secondary refrigerant cooled by the primary refrigerant in the evaporator to the cooling load.
The cooling device according to any one of claims 1 to 12 provided in the secondary refrigerant circuit.
With
A cooling system in which the liquid refrigerant is stored in the liquid receiver as the secondary refrigerant, and the refrigerant pipe forms a part of the secondary refrigerant circuit between the liquid receiver and the liquid pump. The cooling system according to claim 13, wherein the cooling load is an air cooler provided in a refrigerator, and the secondary refrigerant circuit is guided to the air cooler. A pressure sensor that detects the pressure in the liquid receiver and
A temperature sensor that detects the temperature of the liquid refrigerant on the inlet side of the liquid pump, and
A control unit that controls the Peltier element based on the detected values of the pressure sensor and the temperature sensor.
With
The control unit is configured to decrease the current value flowing through the Peltier element when the load of the cooling system increases, and increase the current value flowing through the Peltier element when the load of the cooling system decreases. The cooling system according to claim 13 or 14.

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