Refrigerator unit

Abstract

This refrigerator unit comprises: a compressor unit having an expander and a compressor driven by a drive shaft of a drive device; a first cooler that cools a high-pressure refrigerant gas compressed by the compressor and sends the refrigerant gas to the expander; a second cooler that cools an object to be cooled by a low-pressure refrigerant gas, the expansion energy of which has been recovered by the expander, and returns the refrigerant gas to the compressor; and a regenerative heat exchanger that exchanges heat between the refrigerant gas sent from the first cooler to the expander and the refrigerant gas returned from the second cooler to the compressor. The compressor unit and the regenerative heat exchanger are disposed facing each other in the vertical direction.

Description

Refrigerator unit

[0001] The present disclosure relates to a refrigerator unit.

[0002] A refrigerator cools by the sensible heat of a gas circulating in the gas phase. That is, for example, the refrigerator uses air as a refrigerant, generates high-pressure and high-temperature air by a compressor, cools the high-pressure and high-temperature air with a cooler (heat exchanger), then generates low-pressure and low-temperature air with an expander, and cools an object to be cooled by the sensible heat of the low-pressure and low-temperature air. As such a refrigerator, for example, there is one described in Patent Document 1.

[0003] Japanese Patent No. 5934482

[0004] When using a refrigerator for various applications, miniaturization of the device and improvement of cooling efficiency are required.

[0005] The present disclosure solves the above-described problems and aims to provide a refrigerator unit that achieves miniaturization of the device and improvement of cooling efficiency.

[0006] The refrigerator unit of the present disclosure for achieving the above object includes a compressor unit having a compressor and an expander driven by a drive shaft of a drive device, a first cooler that cools high-pressure refrigerant gas compressed by the compressor and sends it to the expander, a second cooler that cools an object to be cooled with low-pressure refrigerant gas from which expansion energy has been recovered by the expander and returns it to the compressor, and a regenerative heat exchanger that performs heat exchange between the refrigerant gas sent from the first cooler to the expander and the refrigerant gas returned from the second cooler to the compressor, and the compressor unit and the regenerative heat exchanger are arranged to face each other in the vertical direction.

[0007] According to the refrigerator unit of the present disclosure, miniaturization of the device and improvement of cooling efficiency can be achieved.

[0008] Figure 1 is a schematic diagram showing the refrigeration unit of the first embodiment. Figure 2 is a perspective view showing the arrangement of the refrigeration unit of the first embodiment. Figure 3 is a schematic diagram showing the refrigeration unit of the second embodiment. Figure 4 is a schematic diagram showing a modified example of the refrigeration unit of the second embodiment. Figure 5 is a rear view showing the refrigeration unit of the third embodiment. Figure 6 is a schematic diagram showing the cooling path of the refrigeration unit of the fourth embodiment. Figure 7 is a schematic diagram showing a first modified example of the cooling path of the refrigeration unit of the fourth embodiment. Figure 8 is a schematic diagram showing a second modified example of the cooling path of the refrigeration unit of the fourth embodiment. Figure 9 is a schematic diagram showing the control system of the refrigeration unit of the fifth embodiment. Figure 10 is a schematic diagram showing the control system of the refrigeration unit of the sixth embodiment. Figure 11 is a schematic cross-sectional view showing the electric compressor in the refrigeration unit of the seventh embodiment. Figure 12 is a schematic diagram showing the gas supply path of the refrigeration unit of the seventh embodiment. Figure 13 is a schematic diagram showing a modified example of the gas supply path of the refrigeration unit of the seventh embodiment.

[0009] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. However, these embodiments do not limit the present disclosure, and where there are multiple embodiments, they may be combinations of these embodiments. Furthermore, the components in the embodiments include those readily conceivable by those skilled in the art, those that are substantially identical, and those that are equivalent.

[0010] [First Embodiment] <Refrigeration Unit> Figure 1 is a schematic diagram showing the refrigeration unit of the first embodiment.

[0011] As shown in Figure 1, the refrigeration unit 10 comprises a compressor unit 11, a water-cooled heat exchanger (first cooler) 12, a brine heat exchanger (second cooler, brine cooler) 13, and a regenerative heat exchanger 14. The refrigeration unit 10 cools the object to be cooled by flowing a refrigerant gas through the compressor unit 11, the water-cooled heat exchanger 12, the brine heat exchanger 13, and the regenerative heat exchanger 14. Here, it is preferable to use a working fluid such as air, nitrogen, argon, helium, or an organic medium as the refrigerant gas, but it is not limited to these working fluids.

[0012] The compressor unit 11 comprises a drive unit 21, a compressor 22, and an expander 23. The compressor unit 11 has a compressor 22 and an expander 23 driven by a drive shaft 24 of the drive unit 21. The drive unit 21 is an electric motor and has a drive shaft 24 that can be driven and rotated. The compressor 22 is connected to one end of the drive shaft 24 in the axial direction, and the expander 23 is connected to the other end in the axial direction. The compressor 22 has a compressor blade (not shown) attached to one end of the drive shaft 24, and the expander 23 has a turbine blade (not shown) attached to the other end of the drive shaft 24.

[0013] The compressor 22 compresses the refrigerant gas to produce high-pressure refrigerant gas. The compressor 22 is connected to the water-cooled heat exchanger 12 by piping L1. The water-cooled heat exchanger 12 cools the high-pressure refrigerant gas compressed by the compressor 22. The water-cooled heat exchanger 12 is connected to an external cooler 31, and the cooling medium supplied from the cooler 31 cools the high-pressure refrigerant gas compressed by the compressor 22.

[0014] The water-cooled heat exchanger 12 is connected to the expander 23 by piping L2. The expander 23 recovers expansion energy from the high-pressure refrigerant gas cooled in the water-cooled heat exchanger 12 to generate low-pressure refrigerant gas. The expander 23 is connected to the brine heat exchanger 13 by piping L3. The brine heat exchanger 13 cools the brine (object to be cooled) with the low-pressure refrigerant gas from which the expansion energy was recovered in the expander 23. The brine heat exchanger 13 is connected to, for example, a freezer (object to be cooled) 32, and cools the freezer 32 with the cooled brine. The brine heat exchanger 13 is connected to the compressor 22 by piping L4.

[0015] The regenerative heat exchanger 14 is located in piping L2 and L4. In this case, piping L2 includes piping L21 connecting the water-cooled heat exchanger 12 and the regenerative heat exchanger 14, and piping L22 connecting the regenerative heat exchanger 14 and the expander 23. Piping L4 includes piping L41 connecting the brine heat exchanger 13 and the regenerative heat exchanger 14, and piping L42 connecting the regenerative heat exchanger 14 and the compressor 22. The regenerative heat exchanger 14 performs heat exchange between the refrigerant gas sent from the water-cooled heat exchanger 12 to the expander 23 and the refrigerant gas returned from the brine heat exchanger 13 to the compressor 22. That is, the regenerative heat exchanger 14 cools the refrigerant gas sent from the water-cooled heat exchanger 12 to the expander 23 through piping L2 using the low-temperature refrigerant gas returned from the brine heat exchanger 13 to the compressor 22 through piping L4.

[0016] Furthermore, a pipe L5 is provided that connects a pipe L2 that sends refrigerant gas from the water-cooled heat exchanger 12 to the expander 23 and a pipe L4 that returns refrigerant gas from the brine heat exchanger 13 to the compressor 22. A balance valve 33 is provided in the pipe L5. When the balance valve 33 is open, it bypasses a portion of the refrigerant gas flowing through the pipe L2 to the pipe L4.

[0017] In the refrigeration unit 10, when the drive unit 21 is driven, the drive shaft 24 rotates, and the compressor 22 and expander 23 operate. When the compressor 22 operates, it compresses the refrigerant gas to generate high-pressure refrigerant gas, which is sent to the water-cooled heat exchanger 12 through piping L1. The water-cooled heat exchanger 12 cools the high-pressure refrigerant gas compressed by the compressor 22 and sends it to the expander 23 through piping L2. When the expander 23 operates, it recovers expansion energy from the high-pressure refrigerant gas cooled in the water-cooled heat exchanger 12 to generate low-pressure refrigerant gas, which is sent to the brine heat exchanger 13 through piping L3. The brine heat exchanger 13 cools the brine with the low-pressure refrigerant gas from which the expansion energy was recovered in the expander 23, and returns it to the compressor 22 through piping L4. The regenerative heat exchanger 14 cools the refrigerant gas sent from the water-cooled heat exchanger 12 to the expander 23 through the pipe L2 using the low-temperature refrigerant gas returned from the brine heat exchanger 13 to the compressor 22 through the pipe L4.

[0018] Furthermore, when the refrigeration unit 10 is started, the balance valve 33 is opened, and a portion of the refrigerant gas flowing through piping L2 is bypassed and sent to piping L4. If the capacity of the compressor 22 and the expander 23 are different, the flow rates of the refrigerant gas flowing through piping L2 and L4 are balanced. After a predetermined time has elapsed since the refrigeration unit 10 was started, the balance valve 33 is closed.

[0019] The refrigeration unit 10 is a closed-loop type refrigeration unit comprising a compressor unit 11, a water-cooled heat exchanger 12, a brine heat exchanger 13, and a regenerative heat exchanger 14, but it is not limited to this type. For example, the refrigeration unit 10 may be an open-loop type refrigeration unit. In this case, the second cooler is, for example, a cooler that directly supplies and discharges refrigerant gas to the inside of the freezer chamber (object to be cooled) 32.

[0020] <Arrangement of Refrigeration Unit> Figure 2 is a perspective view showing the arrangement of the refrigeration unit in the first embodiment.

[0021] As shown in Figures 1 and 2, the compressor unit 11 and the regenerative heat exchanger 14 are arranged facing each other in the vertical direction. Specifically, the compressor unit 11 is positioned adjacent to the regenerative heat exchanger 14, below it in the vertical direction.

[0022] Furthermore, the water-cooled heat exchanger 12 and the brine heat exchanger 13 are arranged adjacent to each other in the horizontal direction. The water-cooled heat exchanger 12 and the brine heat exchanger 13 are arranged adjacent to the regenerative heat exchanger 14 in the horizontal direction. The brine heat exchanger 13 has one horizontal side (the left side in Figure 2) to which the end of the pipe L3 through which low-pressure refrigerant gas is supplied from the expander 23 is connected, as well as the end of the pipe L41 (L4) through which refrigerant gas is supplied to the regenerative heat exchanger 14 is connected.

[0023] Here, the piping L22 that sends refrigerant gas from the regenerative heat exchanger 14 to the expander 23 is made of metal. The piping L3 that sends low-pressure refrigerant gas from the expander 23 to the brine heat exchanger 13 is made of flexible metal. The piping L42 that returns refrigerant gas from the regenerative heat exchanger 14 to the compressor 22 and the piping L1 that sends high-pressure refrigerant gas from the compressor 22 to the water-cooled heat exchanger 12 are made of rubber. Note that all of the piping L1, L2, L3, and L4 may also be made of metal.

[0024] In the first embodiment of the refrigeration unit 10, the compressor unit 11 is positioned adjacent to the regenerative heat exchanger 14, vertically below it. Therefore, the length of the piping L22 and L42 connecting the compressor unit 11 and the regenerative heat exchanger 14 can be shortened, and the device can be made more compact.

[0025] Furthermore, if the refrigeration unit 10 is of an open-loop type, there is a possibility that refrigerant gas (moisture) may enter the compressor unit 11 (expander 23) and the regenerative heat exchanger 14 and freeze. Therefore, by positioning the compressor unit 11 (expander 23) below the regenerative heat exchanger 14, it becomes easier to discharge moisture from the regenerative heat exchanger 14.

[0026] Furthermore, the water-cooled heat exchanger 12, the brine heat exchanger 13, and the regenerative heat exchanger 14 are arranged adjacent to each other in the horizontal direction. The brine heat exchanger 13 has one horizontal side to which the end of the piping L3 from the expander 23 and the end of the piping L41 (L4) to the regenerative heat exchanger 14 are connected. As a result, the lengths of the piping L3, L41, and L22 can be shortened, and the device can be made smaller. In addition, by shortening the lengths of the piping L3, L41, and L22, the temperature rise of the refrigerant gas can be suppressed, and the cooling efficiency can be improved.

[0027] Furthermore, by using a metal pipe for the piping L22 that sends refrigerant gas from the regenerative heat exchanger 14 to the expander 23, the compressor unit 11 and the regenerative heat exchanger 14 can be firmly connected, thereby suppressing the generation of vibrations. By using a flexible metal pipe for the piping L3 that sends low-pressure refrigerant gas from the expander 23 to the brine heat exchanger 13, and using rubber pipes for the piping L42 that returns refrigerant gas from the regenerative heat exchanger 14 to the compressor 22 and the piping L1 that sends high-pressure refrigerant gas from the compressor 22 to the water-cooled heat exchanger 12, the assembly of various components can be facilitated and assembly efficiency can be improved.

[0028] [Second Embodiment] Figure 3 is a schematic diagram showing the refrigeration unit of the second embodiment. The basic configuration of the second embodiment is the same as that of the second embodiment described above, and will be explained using Figure 2. Components having the same function as those in the first embodiment are denoted by the same reference numerals, and detailed explanations will be omitted.

[0029] As shown in Figures 2 and 3, the housing 40 has a box shape and can be opened and closed by, for example, a lid (not shown). The housing 40 has a lower storage space 42 and an upper storage space 43, with a shelf 41 provided inside.

[0030] The compressor unit 11, water-cooled heat exchanger 12, brine heat exchanger 13, and regenerative heat exchanger 14 that constitute the refrigeration unit 10 are arranged inside the housing 40. Specifically, the refrigeration unit 10 is located in the lower storage space 42 of the housing 40. The refrigeration unit 10 also includes a circulator 15 and an electrical system 16. The circulator 15 and the electrical system 16 are located in the upper storage space 43 of the housing 40.

[0031] Figure 4 is a schematic diagram showing a modified example of the refrigeration unit of the second embodiment.

[0032] As shown in Figures 2 and 4, the refrigeration unit 10 is located in the lower storage space 42 of the housing 40, and the circulator 15 and electrical system 16 are located in the upper storage space 43 of the housing 40. A base 44 is located below the lower storage space 42 of the housing 40. The base 44 has rails (not shown) at its bottom and is movable in the front-rear direction. The refrigeration unit 10 is mounted on the base 44. Therefore, the refrigeration unit 10 can be pulled out of the housing 40 by moving the base 44.

[0033] Although the refrigeration unit 10 is mounted on the base 44, the compressor unit 11 may be mounted on the base 44 alone. Therefore, by removing the piping L1, L22, L3, and L42 connected to the refrigeration unit 10 and then moving the base 44, the compressor unit 11 can be pulled out of the housing 40.

[0034] In the second embodiment, the refrigeration unit 10 can be compactly housed because the refrigeration unit 10 is positioned inside the housing 40. Furthermore, by making the refrigeration unit 10 (compressor unit 11) pull out from the housing 40 using the base 44, the maintainability of the compressor unit 11 can be improved.

[0035] [Third Embodiment] Figure 5 is a rear view showing the refrigeration unit of the third embodiment. Components having the same functions as those in the first embodiment described above are denoted by the same reference numerals and detailed descriptions are omitted.

[0036] As shown in Figures 1 and 5, in the refrigeration unit 10A, the compressor unit 11 and the regenerative heat exchanger 14 are arranged facing each other in the vertical direction. Specifically, the regenerative heat exchanger 14 is positioned adjacent to the compressor unit 11 in the vertical direction below.

[0037] Furthermore, the water-cooled heat exchanger 12 and the brine heat exchanger 13 are arranged adjacent to each other in the horizontal direction. The water-cooled heat exchanger 12 and the brine heat exchanger 13 are arranged adjacent to the regenerative heat exchanger 14 in the horizontal direction. The brine heat exchanger 13 has one horizontal side (the left side in Figure 2) to which the end of the pipe L3 through which low-pressure refrigerant gas is supplied from the expander 23 is connected, as well as the end of the pipe L41 (L4) through which refrigerant gas is supplied to the regenerative heat exchanger 14 is connected.

[0038] In the third embodiment, the refrigeration unit 10A has a regenerative heat exchanger 14 positioned adjacent to the compressor unit 11 in the vertical direction below. Therefore, the length of the piping L22 and L42 connecting the compressor unit 11 and the regenerative heat exchanger 14 can be shortened, making the device more compact. In addition, it is possible to prevent water from condensing outside the regenerative heat exchanger 14 from falling onto the compressor unit 11 when the refrigeration unit 10 is stopped.

[0039] [Fourth Embodiment] Figure 6 is a schematic diagram showing the cooling path of the refrigeration unit of the fourth embodiment. Components having the same function as those in the first embodiment described above are denoted by the same reference numerals, and detailed explanations are omitted.

[0040] As shown in Figure 6, the compressor unit 11 includes a drive unit 21, a compressor 22, and an expander 23, with the compressor 22 and expander 23 connected to a drive shaft 24. The drive unit 21 has an electric motor and an inverter 51 is connected to it. The compressor unit 11 is provided with a cooling path 52 for flowing a cooling medium between the inverter 51 and the drive unit 21. The cooling path 52 is provided with a pump 53 that supplies cooling water as the cooling medium. The inverter 51 and the drive unit 21 are provided with cooling passages for flowing a cooling medium inside. The cooling path 52 is connected in series to each cooling passage of the inverter 51 and the drive unit 21.

[0041] When the compressor unit 11 is in operation, driving the pump 53 supplies cooling water from the inverter 51 to the drive unit 21 via the cooling path 52. As a result, the inverter 51 and the drive unit 21 are properly cooled by the cooling water.

[0042] Figure 7 is a schematic diagram showing a first modified example of the cooling path of the refrigeration unit of the fourth embodiment.

[0043] As shown in Figure 7, the compressor unit 11 is provided with a cooling path 54 that supplies a cooling medium to the inverter 51 and the drive unit 21. The cooling path 54 supplies refrigerant gas as the cooling medium. Specifically, the cooling path 54 is provided by branching off from piping L21, which sends the refrigerant gas compressed by the compressor 22 to the water-cooled heat exchanger 12 via piping L1, and then sends the refrigerant gas from the water-cooled heat exchanger 12 to the regenerative heat exchanger 14. The cooling path 54 is provided with a flow control valve 55. The base end of the cooling path 54 is connected to piping L21, and the other end is connected in series to the respective cooling passages of the inverter 51 and the drive unit 21.

[0044] During the operation of the compressor unit 11, the refrigerant gas compressed by the compressor 22 is sent to the water-cooled heat exchanger 12 through the pipe L1 and cooled, and then sent from the water-cooled heat exchanger 12 to the regenerative heat exchanger 14 through the pipe L21. At this time, a part of the refrigerant gas flowing through the pipe L21 flows into the cooling path 54 in an amount corresponding to the opening degree of the flow rate adjustment valve 55. Then, the refrigerant gas is supplied from the inverter 51 to the drive device 21 through the cooling path 54. Therefore, the inverter 51 and the drive device 21 are appropriately cooled by the refrigerant gas. The cooling gas that cools the inverter 51 and the drive device 21 is returned to the compressor 22.

[0045] FIG. 8 is a schematic diagram showing a second modification of the cooling path of the refrigerator unit according to the fourth embodiment.

[0046] As shown in FIG. 8, the compressor unit 11 is provided with a cooling path 56 through which a cooling medium flows to the inverter 51 and the drive device 21. The cooling path 56 supplies a refrigerant gas as a cooling medium. That is, the cooling path 56 is branched from the pipe L3 that sends the low-pressure refrigerant gas expanded by the expander 23 to the brine heat exchanger 13 through the pipe L3. The cooling path 56 is provided with a flow rate adjustment valve 57. The base end of the cooling path 56 is connected to the pipe L3, and the other end is connected in series to the respective cooling flow paths of the inverter 51 and the drive device 21.

[0047] During the operation of the compressor unit 11, the low-pressure refrigerant gas expanded by the expander 23 is sent to the brine heat exchanger 13 through the pipe L3 and cooled. At this time, a part of the low-pressure refrigerant gas flowing through the pipe L3 flows into the cooling path 56 in an amount corresponding to the opening degree of the flow rate adjustment valve 57. Then, the low-pressure refrigerant gas is supplied from the inverter 51 to the drive device 21 through the cooling path 56. Therefore, the inverter 51 and the drive device 21 are appropriately cooled by the low-pressure refrigerant gas. The cooling gas that cools the inverter 51 and the drive device 21 is returned to the brine heat exchanger 13 or the compressor 22.

[0048] In the above description, the cooling medium is flowed from the inverter 51 to the drive device 21, but it may also be flowed from the drive device 21 to the inverter 51. Further, the cooling medium may be flowed only to the inverter 51 or only to the drive device 21. The cooling medium may be flowed in parallel to the inverter 51 and the drive device 21.

[0049] The refrigerator unit 10 of the fourth embodiment is provided with cooling paths 52, 54, 56 for flowing a cooling medium to the inverter 51 and the drive device 21. Therefore, the inverter 51 and the drive device 21 can be appropriately cooled.

[0050] [Fifth Embodiment] Fig. 9 is a schematic diagram showing a control system of a refrigerator unit according to the fifth embodiment. Members having the same functions as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

[0051] As shown in Fig. 9, the compressor unit 11 includes a drive device 21, a compressor 22, and an expander 23, and the compressor 22 and the expander 23 are connected to a drive shaft 24. The drive device 21 has an electric motor, and the inverter 51 is connected thereto. The inverter 51 has a converter circuit (AC / DC converter) 61 and an inverter circuit 62. The inverter 51 is connected to a control device 63, and the control device 63 is connected to a power supply device 64.

[0052] The power supply device 64 supplies power to the control device 63. The control device 63 supplies power to the inverter 51 and the drive device 21. The converter circuit 61 converts the alternating current from the power supply device 64 into direct current, and the inverter circuit 62 converts the direct current back into alternating current. The inverter 51 changes the voltage and frequency of the electricity and outputs it to the drive device 21. Note that an extended communication interface or CAN (Controller Area Network) communication is applied to the control device 63 and the inverter 51 (converter circuit 61, inverter circuit 62).

[0053] Furthermore, a temperature sensor 65 is provided to measure the temperature of the refrigerant gas returned from the brine heat exchanger 13 to the regenerative heat exchanger 14. The temperature sensor 65 is connected to a control device 63. The control device 63 controls the rotation speed of the drive unit via an inverter 51 based on the temperature of the refrigerant gas measured by the temperature sensor 65. That is, the control device 63 adjusts the rotation speed of the motor in the drive unit so that the temperature of the refrigerant gas at the outlet of the brine heat exchanger 13 reaches a specified optimal temperature, based on the temperature of the refrigerant gas measured by the temperature sensor 65. In this case, if the temperature of the refrigerant gas measured by the temperature sensor 65 is higher than the optimal temperature, the rotation speed of the motor in the drive unit is increased.

[0054] The refrigeration unit 10 of the fifth embodiment is equipped with a temperature sensor 65 that measures the temperature of the refrigerant gas at the outlet of the brine heat exchanger 13, and the control device 63 controls the rotation speed of the drive unit based on the temperature of the refrigerant gas measured by the temperature sensor 65. As a result, the temperature of the refrigerant gas at the outlet of the brine heat exchanger 13 can be adjusted to an optimal temperature.

[0055] [Sixth Embodiment] Figure 10 is a schematic diagram showing the control system of the refrigeration unit of the sixth embodiment. Components having the same functions as those in the first embodiment described above are denoted by the same reference numerals and detailed descriptions are omitted.

[0056] As shown in Figure 10, the control device 63 is connected to a power outage detector 66. The power outage detector 66 detects power loss in the power supply unit 64. The inverter 51 is connected to a power storage device 67. The power storage device 67 is connected to the inverter 51 via a changeover switch 68. The changeover switch 68 is a normally open switch. When the power outage detector 66 detects power loss in the power supply unit 64, it energizes the changeover switch 68. Then, the power storage device 67 is connected to the inverter 51 via the changeover switch 68.

[0057] When the power supply unit 64 is functioning normally, it can supply power to the control device 63, inverter 51, and drive unit 21. When the power outage detector 66 detects a power loss in the power supply unit 64, it energizes the energy storage device and the changeover switch 68, which supply power to the drive unit and the control device. As a result, the energy storage device 67 is connected to the inverter 51 via the changeover switch 68, and the energy storage device 67 becomes capable of supplying power to the control device 63, inverter 51, and drive unit 21.

[0058] The refrigeration unit 10 of the sixth embodiment is equipped with a power outage detector 66 and a power storage device 67. Therefore, even if the power supply unit 64 loses power, power can be supplied from the power storage device 67 to the control device 63, inverter 51, and drive unit 21.

[0059] [Seventh Embodiment] Figure 11 is a schematic cross-sectional view showing the electric compressor in the refrigerator unit of the seventh embodiment, and Figure 12 is a schematic diagram showing the gas supply path of the refrigerator unit of the seventh embodiment. Components having the same functions as those in the first embodiment described above are denoted by the same reference numerals, and detailed descriptions are omitted.

[0060] As shown in Figure 11, the compressor unit 11 includes a drive unit 21, a compressor 22, and an expander 23, with the compressor 22 and expander 23 connected to the drive shaft 24.

[0061] The drive unit 21 comprises a housing 71, a stator 72, a rotating shaft 73, and a rotor 74. The stator 72 is fixed to the inner circumference of the housing 71. The rotating shaft 73 functions as a drive shaft 24, and the rotor 74 is fixed to the outer circumference of the housing 71. The rotating shaft 73 is rotatably supported by the housing 71 by a pair of gas bearings 75 and 76. The gas bearings 75 and 76 are foil-type journal bearings. The rotating shaft 73 is rotatably supported by the housing 71 by a thrust bearing 77. The stator 72 and the rotor 74 face each other with a radial gap between their inner and outer surfaces. Therefore, when current flows through the stator coil of the stator 72, the rotor 74 rotates due to the attractive and repulsive forces of the generated magnetic force, outputting rotational force.

[0062] The drive unit 21 has a compressor 22 positioned on one axial side of the rotating shaft 73 and an expander 23 positioned on the other axial side of the rotating shaft 73. The compressor 22 has a compressor wheel 78 connected to one end of the rotating shaft 73. The expander 23 has a turbine wheel 79 connected to the other end of the rotating shaft 73.

[0063] The drive unit 21 is provided with a refrigerant gas passage 80 inside. The refrigerant gas passage 80 has an inlet passage 81, an axial passage 82, and an outlet passage 83. The inlet passage 81 is provided on the compressor 22 side, with one end opening to the outside of the housing 71 and the other end communicating with the thrust bearing 77 and the gas bearing 75. The axial passage 82 is provided in the gap between the stator 72 and the rotor 74, with one end communicating with the gas bearing 75 and the other end communicating with the gas bearing 76. The outlet passage 83 is provided on the expander 23 side, with one end opening to the outside of the housing 71 and the other end communicating with the gas bearing 76.

[0064] As shown in Figures 11 and 12, the compressor unit 11 is provided with a gas supply path 91 for supplying a cooling medium to the drive unit 21. The gas supply path 91 supplies refrigerant gas, which serves as the cooling medium, to the refrigerant gas flow path 80 of the drive unit 21. The gas supply path 91 is provided by branching off from piping L21, which sends the refrigerant gas compressed by the compressor 22 to the water-cooled heat exchanger 12 via piping L1, and then sends the refrigerant gas from the water-cooled heat exchanger 12 to the regenerative heat exchanger 14. The gas supply path 91 is provided with a flow control valve 92. The base end of the gas supply path 91 is connected to piping L21, and the other end is connected to the inlet side flow path 81 of the refrigerant gas flow path 80 in the drive unit 21.

[0065] While the compressor unit 11 is operating, the refrigerant gas compressed by the compressor 22 is sent to the water-cooled heat exchanger 12 via piping L1 for cooling, and then sent from the water-cooled heat exchanger 12 to the regenerative heat exchanger 14 via piping L21. At this time, a portion of the refrigerant gas flowing through piping L21 flows into the gas supply path 91 in an amount corresponding to the opening degree of the flow control valve 92. As a result, the refrigerant gas is supplied to the drive unit 21 via the gas supply path 91.

[0066] In the drive unit 21, the refrigerant gas supplied from the gas supply path 91 to the refrigerant gas flow path 80 is supplied to the thrust bearing 77 and gas bearing 75 from the inlet flow path 81, flows through the gap between the stator 72 and the rotor 74 via the axial flow path 82 and is supplied to the gas bearing 76, and is discharged to the outside from the outlet flow path 83. As a result, the drive unit 21 is properly cooled by the refrigerant gas, and the thrust bearing 77 and gas bearings 75 and 76 function properly. The cooling gas that has cooled the drive unit 21 is returned to the compressor 22.

[0067] Figure 13 is a schematic diagram showing a modified example of the gas supply path of the refrigeration unit according to the seventh embodiment.

[0068] As shown in Figures 11 and 13, the compressor unit 11 is provided with a gas supply path 93 for supplying a cooling medium to the drive unit 21. The gas supply path 93 supplies refrigerant gas, which serves as the cooling medium, to the refrigerant gas flow path 80 of the drive unit 21. The gas supply path 93 is branched off from piping L3, which sends the low-pressure refrigerant gas expanded by the expander 23 to the brine heat exchanger 13 via piping L3. The gas supply path 93 is provided with a flow control valve 94. The base end of the gas supply path 93 is connected to piping L3, and the other end is connected to the inlet-side flow path 81 of the drive unit 21.

[0069] While the compressor unit 11 is operating, the low-pressure refrigerant gas expanded by the expander 23 is sent to the brine heat exchanger 13 via piping L3 for cooling. At this time, a portion of the low-pressure refrigerant gas flowing through piping L3 flows into the gas supply path 93 in an amount corresponding to the opening of the flow control valve 94. As a result, the low-pressure refrigerant gas is supplied to the drive unit 21 via the gas supply path 93.

[0070] In the drive unit 21, the refrigerant gas supplied from the gas supply path 93 to the refrigerant gas flow path 80 is supplied to the thrust bearing 77 and gas bearing 75 from the inlet flow path 81, flows through the gap between the stator 72 and the rotor 74 via the axial flow path 82 and is supplied to the gas bearing 76, and is discharged to the outside from the outlet flow path 83. As a result, the drive unit 21 ensures that the stator 72 and rotor 74 are properly cooled by the refrigerant gas, and that the thrust bearing 77 and gas bearings 75 and 76 function properly. The cooling gas that has cooled the inverter 51 and the drive unit 21 is returned to the brine heat exchanger 13 or the compressor 22.

[0071] The refrigeration unit 10 of the seventh embodiment is provided with gas supply paths 91 and 93 that supply refrigerant gas to the refrigerant gas passage 80 of the drive unit 21. By supplying refrigerant gas to the thrust bearing 77 and the gas bearings 75 and 76, the thrust bearing 77 and the gas bearings 75 and 76 can be made to function properly.

[0072] [Effects of this embodiment] The refrigeration unit according to the first embodiment comprises a compressor unit 11 having a compressor 22 and an expander 23 driven by a drive shaft of a drive device 21; a water-cooled heat exchanger (first cooler) 12 that cools the high-pressure refrigerant gas compressed by the compressor 22 and sends it to the expander 23; a brine heat exchanger (second cooler, brine cooler) 13 that cools the object to be cooled with the low-pressure refrigerant gas from which the expansion energy has been recovered in the expander 23 and returns it to the compressor 22; and a regenerative heat exchanger 14 that performs heat exchange between the refrigerant gas sent from the water-cooled heat exchanger 12 to the expander 23 and the refrigerant gas returned from the brine heat exchanger 13 to the compressor 22, wherein the compressor unit 11 and the regenerative heat exchanger 14 are arranged facing each other in the vertical direction.

[0073] According to the first embodiment of the refrigeration unit, the compressor unit 11 and the regenerative heat exchanger 14 are arranged facing each other in the vertical direction, which allows the length of the piping L22 and L42 connecting the compressor unit 11 and the regenerative heat exchanger 14 to be shortened. As a result, the size of the device can be reduced.

[0074] The refrigeration unit according to the second embodiment is the same as the refrigeration unit according to the first embodiment, and further, the compressor unit 11 is positioned vertically below the regenerative heat exchanger 14. This makes it possible to miniaturize the device.

[0075] The third embodiment of the refrigeration unit is the same as the first embodiment, and further, the regenerative heat exchanger 14 is positioned vertically below the compressor unit 11. This makes it possible to miniaturize the device.

[0076] The refrigeration unit according to the fourth embodiment is a refrigeration unit according to any one of the first to third embodiments, and furthermore, the brine heat exchanger 13 cools the brine with low-pressure refrigerant gas from which expansion energy has been recovered by the expander 23, and the water-cooled heat exchanger 12 and the brine heat exchanger 13 are arranged adjacent to each other in the horizontal direction. This makes it possible to shorten the lengths of the piping L3, L41, and L22, and to miniaturize the device. In addition, by shortening the lengths of the piping L3, L41, and L22, the temperature rise of the refrigerant gas can be suppressed, and the cooling efficiency can be improved.

[0077] The refrigeration unit according to the fifth embodiment is the same as the refrigeration unit according to the fourth embodiment, further comprising a water-cooled heat exchanger 12 and a brine heat exchanger 13 arranged horizontally adjacent to the regenerative heat exchanger 14. This allows for a reduction in the length of the piping L3, L41, and L22, thereby enabling miniaturization of the device. Furthermore, by reducing the length of the piping L3, L41, and L22, the temperature rise of the refrigerant gas can be suppressed, thereby improving cooling efficiency.

[0078] The sixth embodiment of the refrigeration unit is a refrigeration unit according to any one of the first to fifth embodiments, further comprising a brine heat exchanger 13 that cools the brine with low-pressure refrigerant gas from which expansion energy has been recovered by the expander 23, and the brine heat exchanger 13 has the end of a pipe L3 from which low-pressure refrigerant gas is supplied from the expander 23 connected to one horizontal side, and the end of a pipe L41 for refrigerant gas supplied to the regenerative heat exchanger 14 connected to it. This makes it easy to arrange the pipes L3 and L41 connected to the brine heat exchanger 13.

[0079] The seventh embodiment of the refrigeration unit is a refrigeration unit according to any one of the first to sixth embodiments, further comprising: a metal pipe L22 that sends refrigerant gas from the regenerative heat exchanger 14 to the expander 23; a flexible metal pipe L3 that sends low-pressure refrigerant gas from the expander 23 to the brine heat exchanger 13; and rubber pipes L42 that returns refrigerant gas from the regenerative heat exchanger 14 to the compressor 22 and L1 that sends high-pressure refrigerant gas from the compressor 22 to the water-cooled heat exchanger 12. This allows the compressor unit 11 and the regenerative heat exchanger 14 to be firmly connected by the metal pipes, thereby suppressing the generation of vibrations. In addition, the flexible metal pipes and rubber pipes facilitate the assembly of various components, improving ease of assembly.

[0080] The eighth embodiment of the refrigeration unit is a refrigeration unit according to any one of the first to seventh embodiments, further comprising a compressor unit 11, a water-cooled heat exchanger 12, a brine heat exchanger 13, and a regenerative heat exchanger 14, all of which are arranged inside the housing 40. At least the compressor unit 11 is supported by a movable base 44 and can be pulled out from the housing 40. This improves the maintainability of the refrigeration unit 10 (compressor unit 11).

[0081] The ninth embodiment of the refrigeration unit is a refrigeration unit according to any one of the first to eighth embodiments, further comprising cooling paths 52, 54, and 56 for circulating a cooling medium to the drive unit 21 and the inverter 51 of the drive unit 21. This allows the inverter 51 and the drive unit 21 to be properly cooled.

[0082] The refrigeration unit according to the tenth embodiment is the refrigeration unit according to the ninth embodiment, further wherein the cooling medium is a refrigerant gas that has been compressed by the compressor 22 and then cooled by the water-cooled heat exchanger 12, or a low-pressure refrigerant gas from which the expansion energy has been recovered by the expander 23. By using a refrigerant gas as the cooling medium, a pump can be eliminated, thereby simplifying the device.

[0083] The refrigeration unit according to the eleventh embodiment is a refrigeration unit according to any one of the first to tenth embodiments, and further comprises a brine heat exchanger 13 that cools the brine with low-pressure refrigerant gas from which expansion energy has been recovered by the expander 23, a temperature sensor 65 that measures the temperature of the refrigerant gas returned from the brine heat exchanger 13 to the regenerative heat exchanger 14, and a control device 63 that controls the rotation speed of the drive unit 21 based on the temperature of the refrigerant gas measured by the temperature sensor 65. This makes it possible to adjust the temperature of the refrigerant gas at the outlet of the brine heat exchanger 13 to an optimal temperature, and to operate the refrigeration unit 10 appropriately.

[0084] The 12th embodiment of the refrigeration unit is the 11th embodiment of the refrigeration unit, further comprising a power supply unit 64 that supplies power to the drive unit 21 and the control unit 63, a power outage detector 66 that detects power loss of the power supply unit 64, and a power storage device 67 that supplies power to the drive unit 21 and the control unit 63 when the power outage detector 66 detects power loss of the power supply unit 64. As a result, even if the power supply unit 64 loses power, power can be supplied from the power storage device 67 to the control unit 63, inverter 51, and drive unit 21, allowing the refrigeration unit 10 to operate continuously.

[0085] The refrigeration unit according to the 13th embodiment is a refrigeration unit according to any one of the first to 12th embodiments, further comprising: a housing 71 having a stator 72 with a cylindrical shape on its inner circumference; a rotating shaft 73 having a rotor 74 disposed inside the housing 71 and facing the stator 72; gas bearings 75, 76 that rotatably support the rotating shaft 73; and gas supply paths 91, 93 that supply high-pressure refrigerant gas compressed by a compressor 22 and then cooled by a water-cooled heat exchanger 12, or low-pressure refrigerant gas from which expansion energy has been recovered by an expander 23, to the gas bearings 75, 76. As a result, by supplying refrigerant gas to the refrigerant gas flow path 80 of the drive unit 21 via the gas supply paths 91, 93, the thrust bearing 77 and the gas bearings 75, 76 can be made to function properly with the refrigerant gas.

[0086] 10, 10A Refrigeration Unit 11 Compressor Unit 12 Water-cooled heat exchanger (first cooler) 13 Brine heat exchanger (second cooler, brine cooler) 14 Regenerative heat exchanger 21 Drive unit 22 Compressor 23 Expander 24 Drive shaft 31 Cooler 32 Refrigeration chamber 33 Balance valve 51 Inverter 52, 54, 56 Cooling path 53 Pump 55, 57 Flow control valve 61 Converter circuit 62 Inverter circuit 63 Control device 64 Power supply unit 65 Temperature sensor 66 Power failure detector 67 Energy storage device 68 Changeover switch 71 Housing 72 Stator 73 Rotating shaft 74 Rotor 75, 76 Gas bearing 77 Thrust bearing 78 Compressor wheel 79 Turbine wheel 80 Refrigerant gas flow path 81 Inlet flow path 82 Axial flow path 83 Outlet flow path 91 Gas supply path 92 Flow control valves L1, L2, L21, L22, L3, L4, L41, L42, L5 Piping

Claims

1. A refrigeration unit comprising: a compressor unit having a compressor and an expander driven by a drive shaft of a drive device; a first cooler that cools the high-pressure refrigerant gas compressed by the compressor and sends it to the expander; a second cooler that cools an object to be cooled with the low-pressure refrigerant gas from which the expansion energy has been recovered by the expander and returns it to the compressor; and a regenerative heat exchanger that performs heat exchange between the refrigerant gas sent from the first cooler to the expander and the refrigerant gas returned from the second cooler to the compressor, wherein the compressor unit and the regenerative heat exchanger are arranged facing each other in the vertical direction.

2. The refrigeration unit according to claim 1, wherein the compressor unit is positioned vertically below the regenerative heat exchanger.

3. The refrigeration unit according to claim 1, wherein the regenerative heat exchanger is positioned vertically below the compressor unit.

4. The refrigerator unit according to claim 1, wherein the second cooler is a brine cooler that cools the brine with a low-pressure refrigerant gas from which the expansion energy has been recovered by the expander, and the first cooler and the brine cooler are arranged adjacent to each other in the horizontal direction.

5. The refrigeration unit according to claim 4, wherein the first cooler and the brine cooler are arranged horizontally adjacent to the regenerative heat exchanger.

6. The refrigeration unit according to claim 1, wherein the second cooler is a brine cooler that cools the brine with low-pressure refrigerant gas from which expansion energy has been recovered by the expander, and the end of a pipe from which low-pressure refrigerant gas is supplied from the expander is connected to one horizontal side of the brine cooler, and the end of a pipe from which refrigerant gas is supplied to the regenerative heat exchanger is also connected.

7. The refrigeration unit according to claim 1, wherein the piping that supplies refrigerant gas from the regenerative heat exchanger to the expander is made of metal, the piping that supplies low-pressure refrigerant gas from the expander to the second cooler is made of flexible metal, and the piping that returns refrigerant gas from the regenerative heat exchanger to the compressor and the piping that supplies high-pressure refrigerant gas from the compressor to the first cooler are made of rubber.

8. The refrigeration unit according to claim 1, wherein the compressor unit, the first cooler, the second cooler, and the regenerative heat exchanger are arranged inside a housing, and at least the compressor unit is supported on a movable base and can be pulled out from the housing.

9. The refrigeration unit according to claim 1, wherein a cooling path is provided for flowing a cooling medium to the drive unit and the inverter of the drive unit.

10. The refrigeration unit according to claim 9, wherein the cooling medium is a refrigerant gas that has been compressed by the compressor and then cooled by the first cooler, or a low-pressure refrigerant gas from which expansion energy has been recovered by the expander.

11. The refrigerator unit according to claim 1, wherein the second cooler is a brine cooler that cools the brine with low-pressure refrigerant gas from which expansion energy has been recovered by the expander, and comprises a temperature sensor for measuring the temperature of the refrigerant gas returned from the brine cooler to the regenerative heat exchanger, and a control device for controlling the rotation speed of the drive unit based on the temperature of the refrigerant gas measured by the temperature sensor.

12. The refrigeration unit according to claim 11, further comprising: a power supply unit that supplies power to the drive unit and the control unit; a power outage detector that detects power loss of the power supply unit; and a power storage device that supplies power to the drive unit and the control unit when the power outage detector detects power loss of the power supply unit.

13. The refrigeration unit according to claim 1, wherein the drive device comprises a housing having a cylindrical stator on its inner circumference, a rotating shaft having a rotor disposed inside the housing and facing the stator, a gas bearing that rotatably supports the rotating shaft, and a gas supply path that supplies high-pressure refrigerant gas compressed by the compressor and then cooled by the first cooler or low-pressure refrigerant gas from which expansion energy has been recovered by the expander to the gas bearing.

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