Refrigerator unit
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-08-25
- Publication Date
- 2026-08-13
Smart Images
Figure JP2025029683_13082026_PF_FP_ABST
Abstract
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] International Publication No. 2023 / 120053
[0004] In a refrigerator, a compressor compresses a refrigerant gas to generate a high-pressure refrigerant gas, a cooler cools the high-pressure refrigerant gas, an expander recovers expansion energy from the high-pressure refrigerant gas to generate a low-pressure refrigerant gas, and the low-pressure refrigerant gas cools an object to be cooled. In this case, since an ultra-low temperature refrigerant gas flows through the expander and the pipes connected to the expander, etc., the outside air is cooled and the moisture contained in the air freezes, and ice adheres to the outer surfaces of the expander and the pipes, etc. Then, when the operation of the refrigerator stops, since no ultra-low temperature refrigerant gas flows through the expander and the pipes, the ice adhering to the outer surfaces of the expander and the pipes, etc. melts and becomes drain. The generated drain is received by a drain pan, but since it increases every time the operation and stop of the refrigerator are repeated, it is necessary to drain the water before it leaks from the drain pan.
[0005] The present disclosure solves the above-described problems, and an object thereof is to provide a refrigerator unit capable of appropriately treating the generated drain.
[0006] To achieve the above objectives, the refrigeration unit of the present disclosure comprises: a compressor unit having a compressor and an expander driven and connected to a drive shaft of a drive unit; a first cooler that cools the high-pressure refrigerant gas compressed by the compressor and sends it to the expander as low-pressure refrigerant gas; and a regenerative heat exchanger that performs heat exchange between the low-pressure refrigerant gas sent from the first cooler to the expander and the used low-pressure refrigerant gas returned to the compressor, wherein the first cooler has an inlet pipe connected to its lower vertical end for supplying refrigerant gas from the compressor, and an outlet pipe connected to its upper vertical end for discharging refrigerant gas, and a portion of the inlet pipe is positioned vertically below the central axis of the rotating shaft arranged horizontally in the compressor.
[0007] According to the refrigeration unit of this disclosure, the generated drain can be properly handled.
[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 front view showing the arrangement of the refrigeration unit. Figure 4 is a rear view showing the arrangement of the refrigeration unit. Figure 5 is a side view showing the arrangement of the refrigeration unit. Figure 6 is a front view showing the arrangement of the refrigeration unit of the second embodiment. Figure 7 is a front view showing the arrangement of the refrigeration unit of the third embodiment. Figure 8 is a schematic cross-sectional view showing the compressor unit in the refrigeration unit of the fourth embodiment. Figure 9 is a schematic diagram showing 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.
[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 (not shown) and cools the high-pressure refrigerant gas compressed by the compressor 22 with a cooling medium supplied from the cooler.
[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 (not shown) to be cooled, and cools the freezer 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] 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.
[0017] In this example, 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 the case of an open-loop type refrigeration unit, the second cooler is not an essential component, and it is sufficient to supply and discharge refrigerant gas directly to and from the freezer chamber (the object to be cooled).
[0018] <Arrangement of Refrigeration Unit> Figure 2 is a perspective view showing the arrangement of the refrigeration unit in the first embodiment, Figure 3 is a front view showing the arrangement of the refrigeration unit, Figure 4 is a rear view showing the arrangement of the refrigeration unit, and Figure 5 is a side view showing the arrangement of the refrigeration unit. However, in Figure 5, the water-cooled heat exchanger is represented by a dashed line.
[0019] As shown in Figures 2 and 3, the refrigeration unit 10 comprises at least a compressor unit 11, a water-cooled heat exchanger (first cooler) 12, and a regenerative heat exchanger 14. However, in the following description, the refrigeration unit 10 will be described as comprising a compressor unit 11, a water-cooled heat exchanger 12, a brine heat exchanger (second cooler, brine cooler) 13, and a regenerative heat exchanger 14.
[0020] In the refrigeration unit 10, the compressor unit 11 and the regenerative heat exchanger 14 are arranged facing each other in the vertical direction (height direction H). Specifically, the compressor unit 11 is arranged adjacent to the regenerative heat exchanger 14 in the vertical direction below. In this case, when we say that the compressor unit 11 and the regenerative heat exchanger 14 are arranged facing each other in the vertical direction, it means that a part of the compressor unit 11, for example, one of the drive unit 21, compressor 22, and expander 23, or a part thereof, is arranged facing a part of the regenerative heat exchanger 14 in the vertical direction. The water-cooled heat exchanger 12, brine heat exchanger 13, and regenerative heat exchanger 14 are arranged adjacent to each other in the horizontal direction (width direction W, depth direction D). That is, the water-cooled heat exchanger 12 and brine heat exchanger 13 are arranged adjacent to each other in the width direction. The water-cooled heat exchanger 12 and brine heat exchanger 13 and regenerative heat exchanger 14 are arranged adjacent to each other in the depth direction.
[0021] The compressor unit 11 is positioned vertically below the regenerative heat exchanger 14, and the central axis O1 of the drive shaft 24 (see Figure 1) is aligned horizontally. Here, the central axis O1 of the drive shaft 24 is aligned in a straight line with the central axis of the rotating shaft in the compressor 22 and the central axis of the rotating shaft in the expander 23.
[0022] The regenerative heat exchanger 14 is positioned along the central axis O1 of the drive shaft 24 in the compressor unit 11. That is, the longitudinal direction (width direction) of the regenerative heat exchanger 14 and the axial direction of the drive shaft 24 in the compressor unit 11 are in the same direction. In addition, the water-cooled heat exchanger 12, the brine heat exchanger 13, and the regenerative heat exchanger 14 are in the same direction in terms of height, width, and depth.
[0023] The piping L42 that supplies refrigerant gas from the regenerative heat exchanger 14 to the compressor 22 is a bent pipe that bends at a 90-degree angle. The piping L1 that supplies refrigerant gas from the compressor 22 to the water-cooled heat exchanger 12 is a bent pipe that bends at a 90-degree angle. The piping L3 that supplies refrigerant gas from the expander 23 to the brine heat exchanger 13 is a bent pipe that bends at a 180-degree angle. The piping L22 that supplies refrigerant gas from the regenerative heat exchanger 14 to the expander 23 is a bent pipe that bends at a 90-degree angle. Also, the piping L41 that supplies refrigerant gas from the brine heat exchanger 13 to the regenerative heat exchanger 14 is a bent pipe that bends at a 180-degree angle. The piping L21 that supplies refrigerant gas from the water-cooled heat exchanger 12 to the regenerative heat exchanger 14 is a bent pipe that bends at a 90-degree angle.
[0024] Here, it is preferable that the piping L22 that sends refrigerant gas from the regenerative heat exchanger 14 to the expander 23, the piping L3 that sends low-pressure refrigerant gas from the expander 23 to the brine heat exchanger 13, and the piping L41 that sends refrigerant gas from the brine heat exchanger 13 to the regenerative heat exchanger 14 be made of metal. On the other hand, it is preferable that the piping L42 that returns refrigerant gas from the regenerative heat exchanger 14 to the compressor 22, the piping L1 that sends high-pressure refrigerant gas from the compressor 22 to the water-cooled heat exchanger 12, and the piping L21 that sends refrigerant gas from the water-cooled heat exchanger 12 to the regenerative heat exchanger 14 be made of rubber.
[0025] As shown in Figures 4 and 5, the water-cooled heat exchanger 12 has a pipe (inlet pipe) L1 connected to the lower vertical side to supply refrigerant gas from the compressor 22, and a pipe (outlet pipe) L21 connected to the upper vertical side to discharge the refrigerant gas. The pipe L1 that supplies refrigerant gas from the compressor 22 to the water-cooled heat exchanger 12 is partially located vertically below the central axis of the rotating shaft in the compressor 22, that is, below the central axis O1 of the drive shaft 24 in the compressor unit 11. Specifically, part of the centerline of the pipe L1 is located vertically below the central axis O1 of the drive shaft 24.
[0026] A portion of the piping L1 is positioned vertically below the compressor unit 11. Specifically, the lowest surface of piping L1 is positioned vertically below the lowest surfaces of the drive unit 21, compressor 22, and expander 23 that constitute the compressor unit 11. Furthermore, a portion of piping L1 is positioned vertically below the piping L42 that returns refrigerant gas to the compressor 22. In addition, the center of the inlet 12a of the water-cooled heat exchanger 12, to which piping L1 is connected, is positioned vertically below the central axis of the rotation axis of the compressor 22, that is, below the central axis O1 of the drive shaft 24 in the compressor unit 11. Furthermore, a portion of piping L1 is positioned vertically below the lower surface of the brine heat exchanger 13.
[0027] In other words, the base end of the pipe L1 is connected to the side of the compressor 22, and the other end is connected to the inlet 12a provided on the side of the water-cooled heat exchanger 12. That is, the pipe L1 extends from the side of the compressor 22 perpendicular to the central axis O1 and diagonally downward in the vertical direction, so that its center is located vertically below the central axis O1 of the drive shaft 24. The pipe L1 then bends and extends horizontally perpendicular to the central axis O1, bends horizontally by about 90 degrees, and then extends in a direction parallel to the central axis O1 and is connected to the inlet 12a of the water-cooled heat exchanger 12. A portion of the pipe L1 that is parallel to the central axis O1 and connected to the inlet 12a of the water-cooled heat exchanger 12 is located vertically below the central axis O1.
[0028] However, the piping L1 is not limited to a region located vertically below the central axis O1. It is sufficient that a portion of the piping L1 is located vertically below the central axis O1. For example, the piping L1 may extend downward from the bottom of the compressor 22 perpendicular to the central axis O1 so that a portion of it is located vertically below the central axis O1. Alternatively, the piping L1 may be configured to extend in a direction parallel to the central axis O1 and then bend upward to connect to the inlet 12a of the water-cooled heat exchanger 12.
[0029] The refrigeration unit 10 has a drain pan 35. The drain pan 35 is located below the compressor unit 11, the water-cooled heat exchanger 12, the brine heat exchanger 13, and the regenerative heat exchanger 14. The drain pan 35 is for receiving the drain that falls from the refrigeration unit 10. The drain pan 35 has a rectangular horizontal section 35a and a frame section 35b provided around the horizontal section 35a. The refrigeration unit 10 is supported on a base (not shown) via a support frame or the like, and the drain pan 35 is supported and positioned between the base and the refrigeration unit 10 or below the base.
[0030] <Operation of the Refrigeration Unit> When the refrigeration unit 10 is operating, the compressor 22 compresses the refrigerant gas to generate high-pressure refrigerant gas, the water-cooled heat exchanger 12 cools the high-pressure refrigerant gas, the expander 23 recovers expansion energy from the high-pressure refrigerant gas to generate low-pressure refrigerant gas, and the brine heat exchanger 13 cools the brine with the low-pressure refrigerant gas and returns it to the compressor 22. In this case, the compressor 22, the water-cooled heat exchanger 12, and the piping L1, L21, L42 are in the high-temperature region (right side of Figure 3), while the expander 23, the brine heat exchanger 13, and the piping L22, L3, L41 are in the low-temperature region (left side of Figure 6). Therefore, in the low-temperature region, the moisture contained in the air freezes as the outside air is cooled, and ice forms on the outer surfaces of the expander 23, the brine heat exchanger 13, and the piping L22, L3, L41.
[0031] Then, when the operation of the refrigeration unit 10 stops, the low-temperature region returns to the room-temperature region, and the ice that has formed on the expander 23, brine heat exchanger 13, and piping L22, L3, and L41 melts into water, which falls into the drain pan 35, and the drain pan 35 stores a predetermined amount of drain.
[0032] Subsequently, when the refrigeration unit 10 operates again, the high-temperature and low-temperature regions described above are generated. At this time, the piping L1 located in the high-temperature region is heated by the flow of high-temperature, high-pressure refrigerant gas from the compressor 22 towards the water-cooled heat exchanger 12. As a result, the radiant heat from the heated piping L1 is transferred to the drain stored in the drain pan 35, causing the drain to heat up and evaporate as water vapor. Therefore, by evaporating the drain stored in the drain pan 35, there is no need to drain the drain. On the other hand, the piping L1 is cooled by the heat being absorbed by the drain.
[0033] In this configuration, a portion of the piping L1 located in the high-temperature region is positioned below the central axis O1 of the drive shaft 24 in the compressor unit 11, thereby positioning a portion of the piping L1 opposite the drain stored in the drain pan 35. However, the configuration is not limited to this. For example, a portion of the piping L1 may be positioned to be in contact with the drain stored in the drain pan 35.
[0034] In the first embodiment of the refrigeration unit 10, a portion of the piping L1 that supplies refrigerant gas from the compressor 22 to the water-cooled heat exchanger 12 is positioned vertically below the central axis of the rotating shaft in the compressor 22 (the central axis O1 of the drive shaft 24 in the compressor unit 11). Therefore, the heat from the piping L1, which is in the high-temperature region, heats and evaporates the drain stored in the drain pan 35, thereby reducing the amount of drain. This eliminates the need to drain the drain separately, and the generated drain can be properly handled.
[0035] [Second Embodiment] Figure 6 is a front view showing the arrangement of the refrigeration unit according to the second embodiment. Components having the same functions as those in the first embodiment described above are denoted by the same reference numerals, and detailed explanations are omitted.
[0036] As shown in Figure 6, the refrigeration unit 10A comprises a compressor unit 11, a water-cooled heat exchanger 12, a brine heat exchanger 13, and a regenerative heat exchanger 14. In the refrigeration unit 10A, 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 compressor unit 11 is arranged adjacent to the regenerative heat exchanger 14, vertically below it.
[0037] The water-cooled heat exchanger 12 has a pipe L1 connected to its lower vertical end for supplying refrigerant gas from the compressor 22, and a pipe L21 connected to its upper vertical end for discharging refrigerant gas. Part of the pipe L1 that supplies refrigerant gas from the compressor 22 to the water-cooled heat exchanger 12 is positioned vertically below the central axis of the rotating shaft in the compressor 22, that is, below the central axis O1 of the drive shaft 24 in the compressor unit 11. Specifically, part of the centerline of the pipe L1 is located vertically below the central axis O1 of the drive shaft 24.
[0038] The refrigeration unit 10A has a drain pan 35A. The drain pan 35A is located below the compressor unit 11, the water-cooled heat exchanger 12, the brine heat exchanger 13, and the regenerative heat exchanger 14. The drain pan 35A is for receiving the drain that falls from the refrigeration unit 10A. The drain pan 35A has a horizontal section 35a, a frame section 35b, and an inclined section 35c.
[0039] The water-cooled heat exchanger 12 and the brine heat exchanger 13 are arranged adjacent to each other along the width direction. In the refrigeration unit 10A, the compressor 22, the water-cooled heat exchanger 12, and the piping L1, L21, and L42 are in the high-temperature region (right side in Figure 6), while the expander 23, the brine heat exchanger 13, and the piping L22, L3, and L41 are in the low-temperature region (left side in Figure 6). The inclined portion 35c of the drain pan 35A is inclined vertically upward on the low-temperature region side (left side in Figure 6) relative to the horizontal portion 35a, where the brine heat exchanger 13 is located. In other words, the horizontal portion 35a is located below the high-temperature region, the inclined portion 35c is located below the low-temperature region, and the inclined portion 35c is inclined upward from the end of the horizontal portion 35a on the low-temperature region side toward the brine heat exchanger 13.
[0040] When the refrigeration unit 10A is operating, the outside air is cooled in the low-temperature region where the brine heat exchanger 13 and other components are located. As a result, the moisture in the air freezes, and ice forms on the outer surfaces of the expander 23, the brine heat exchanger 13, and the piping L22, L3, and L41. When the refrigeration unit 10A stops operating, the low-temperature region returns to the ambient temperature region, and the ice on the expander 23, the brine heat exchanger 13, and the piping L22, L3, and L41 melts into water, which falls into the drain pan 35A, where it stores a predetermined amount of drain. At this time, the drain descending from the brine heat exchanger 13 and other components falls into the inclined section 35c of the drain pan 35A, flows down the inclined section 35c, and is stored in the horizontal section 35a on the high-temperature region side.
[0041] Subsequently, when the refrigeration unit 10A operates again, a high-temperature region and a low-temperature region are created. At this time, the piping L1 located in the high-temperature region is heated by the flow of high-temperature, high-pressure refrigerant gas from the compressor 22 towards the water-cooled heat exchanger 12. Then, the radiant heat from the heated piping L1 is transferred to the drain stored in the horizontal section 35a of the drain pan 35A, causing the drain to heat up and evaporate as water vapor. Therefore, by evaporating the drain stored in the horizontal section 35a of the drain pan 35, there is no need to drain the drain. On the other hand, the expander 23, brine heat exchanger 13, and piping L22 and L3 located on the low-temperature region side do not come into contact with the drain stored in the drain pan 35A, thus preventing re-icing.
[0042] The refrigeration unit 10A of the second embodiment has a compressor unit 11, a water-cooled heat exchanger 12, a brine heat exchanger 13, and a drain pan 35A located below the regenerative heat exchanger 14. The drain pan 35A has an inclined portion 35c on the low-temperature region side where the brine heat exchanger 13 is located, which slopes vertically upward. Drain descending from the brine heat exchanger 13 and the like falls into the inclined portion 35c of the drain pan 35A and flows into the horizontal portion 35a on the high-temperature region side where it is stored. Therefore, the amount of drain stored in the drain pan 35A can be efficiently reduced by heating and evaporating the drain stored in the horizontal portion 35a of the drain pan 35A with the heat from the piping L1 in the high-temperature region.
[0043] [Third Embodiment] FIG. 7 is a front view showing the arrangement of the refrigerator unit according to the third embodiment. Note that members having the same functions as those in the above-described second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0044] As shown in FIGS. 1 and 7, the refrigerator unit 10B includes a compressor unit 11, a water-cooled heat exchanger 12, a brine heat exchanger 13, and a regenerative heat exchanger 14. In the refrigerator unit 10B, 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. And the compressor unit 11 is arranged adjacent to the lower side in the vertical direction of the regenerative heat exchanger 14.
[0045] A pipe L1 for supplying refrigerant gas from the compressor 22 to the water-cooled heat exchanger 12 is partially arranged along the horizontal direction in the compressor 22, that is, below the central axis of the rotating shaft, that is, below the central axis O1 of the drive shaft 24 in the compressor unit 11 in the vertical direction. Specifically, a part of the center line of the pipe L1 is located below the central axis O1 of the drive shaft 24 in the vertical direction.
[0046] The refrigerator unit 10B has a drain pan 35A. The drain pan 35A is arranged below the compressor unit 11, the water-cooled heat exchanger 12, the brine heat exchanger 13, and the regenerative heat exchanger 14. The drain pan 35A receives the drain that has fallen from the refrigerator unit 10B. The drain pan 35A has a horizontal portion 35a, a frame portion 35b, and an inclined portion 35c.
[0047] In the refrigerator unit 10B, the compressor 22, the water-cooled heat exchanger 12, and the pipes L1, L21, and L42 are in the high-temperature region (the right side in FIG. 7), and the expander 23, the brine heat exchanger 13, and the pipes L22, L3, and L41 are in the low-temperature region (the left side in FIG. 7). The regenerative heat exchanger 14 is disposed opposite to the water-cooled heat exchanger 12 and the brine heat exchanger 13 in the depth direction. The regenerative heat exchanger 14 is inclined such that the low-temperature region (the left side in FIG. 7) where the brine heat exchanger 13 is arranged faces downward in the vertical direction. Also, the inclined portion 35c of the drain pan 35A is inclined such that the low-temperature region side (the left side in FIG. 7) where the brine heat exchanger 13 is arranged faces upward in the vertical direction with respect to the horizontal portion 35a.
[0048] When the refrigerator unit 10B is in operation, in the low-temperature region where the brine heat exchanger 13 and the like are arranged, the external air is cooled, so that the moisture contained in the air freezes, and icing occurs on the outer surfaces of the expander 23, the brine heat exchanger 13, and the pipes L22, L3, and L41. Also, the regenerative heat exchanger 14 may be iced at the end on the brine heat exchanger 13 side. When the operation of the refrigerator unit 10B stops, the low-temperature region becomes a normal-temperature region, and the icing on the expander 23, the brine heat exchanger 13, and the pipes L22, L3, and L41 melts into water and drops into the drain pan 35A, and the drain pan 35A stores a predetermined amount of drain. At this time, since the regenerative heat exchanger 14 is inclined, the drain flows toward the brine heat exchanger 13 side and drops into the drain pan 35A. Also, the drain descending from the brine heat exchanger 13 and the like drops onto the inclined portion 35c of the drain pan 35A, flows through the inclined portion 35c, and is stored in the horizontal portion 35a on the high-temperature region side.
[0049] After that, when the refrigerator unit 10B operates again, a high-temperature region and a low-temperature region are generated. At this time, the pipe L1 located in the high-temperature region is heated by the high-temperature and high-pressure refrigerant gas flowing from the compressor 22 toward the water-cooled heat exchanger 12. Then, the radiant heat of the heated pipe L1 is transmitted to the drain stored in the horizontal portion 35a of the drain pan 35A, and the drain is heated and turns into water vapor and evaporates. Therefore, by evaporating the drain stored in the horizontal portion 35a of the drain pan 35, it is not necessary to drain the drain. On the other hand, the expander 23, the brine heat exchanger 13, and the pipes L22 and L3 arranged on the low-temperature region side do not come into contact with the drain stored in the drain pan 35A, and re-icing is prevented.
[0050] The refrigeration unit 10B of the third embodiment has a compressor unit 11, a water-cooled heat exchanger 12, a brine heat exchanger 13, and a drain pan 35A located below the regenerative heat exchanger 14. The regenerative heat exchanger 14 is inclined so that the low-temperature region side where the brine heat exchanger 13 is located is inclined vertically downward. Drain from the end of the regenerative heat exchanger 14 on the brine heat exchanger 13 side falls into the inclined portion 35c of the drain pan 35A. As a result, the drain descending from the end of the regenerative heat exchanger 14 is prevented from adhering to the drive unit 21 of the compressor unit 11, improving the reliability of the compressor unit 11.
[0051] [Fourth Embodiment] Figure 8 is a schematic cross-sectional view showing the compressor unit in the refrigeration unit of the fourth 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.
[0052] As shown in Figure 8, 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.
[0053] The drive unit 21 comprises a housing 41, a stator 42, a rotating shaft 43, and a rotor 44. The stator 42 is fixed to the inner circumference of the housing 41. The rotating shaft 43 functions as the drive shaft 24, and the rotor 44 is fixed to the outer circumference. The rotating shaft 43 is rotatably supported by the housing 41 by a pair of journal bearings 45 and 46. The journal bearings 45 and 46 are gas bearings. The journal bearings 45 and 46 support one side (right side in Figure 7) and the other side (left side in Figure 7) of the rotating shaft 43 in the axial direction. The rotating shaft 43 is rotatably supported by the housing 41 by a thrust bearing 47. The thrust bearing 47 is a gas bearing. The thrust bearing 47 is a disc member fixed to one side of the rotating shaft 43 in the axial direction.
[0054] The stator 42 and rotor 44 face each other with a radial gap between their inner and outer surfaces. Therefore, when current flows through the stator coil of the stator 42, the rotor 44 rotates due to the attractive and repulsive forces of the generated magnetic field, outputting rotational force.
[0055] The drive unit 21 has a compressor 22 positioned on one axial side of the rotating shaft 43 and an expander 23 positioned on the other axial side of the rotating shaft 43. The compressor 22 has a compressor wheel 48 connected to one end of the rotating shaft 43. The expander 23 has a turbine wheel 49 connected to the other end of the rotating shaft 43.
[0056] The drive unit 21 has a refrigerant gas passage 50 inside. The refrigerant gas passage 50 has an inlet passage 51, an axial passage 52, and an outlet passage (not shown). The inlet passage 51 is located on the compressor 22 side, with one end opening to the outside of the housing 41 and the other end communicating with the thrust bearing 47 and the journal bearing 46. The axial passage 52 is located in the gap between the stator 42 and the rotor 44, with one end communicating with the journal bearing 45 and the other end communicating with the journal bearing 46. The outlet passage is located on the expander 23 side, with one end opening to the outside of the housing 41 and the other end communicating with the journal bearing 46.
[0057] As shown in Figures 1 and 8, the compressor unit 11 is provided with a gas supply path 55 for supplying a cooling medium to the drive unit 21. The gas supply path 55 extracts refrigerant gas as a cooling medium and supplies it to the refrigerant gas flow path 50 of the drive unit 21. That is, the gas supply path 55 supplies refrigerant gas compressed by the compressor 22 or refrigerant gas from which expansion energy has been recovered by the expander 23 to the inlet flow path 51.
[0058] In the drive unit 21, the refrigerant gas supplied from the gas supply path 55 to the refrigerant gas flow path 50 is supplied to the thrust bearing 47 and journal bearing 46 from the inlet flow path 51, flows through the gap between the stator 42 and the rotor 44 via the axial flow path 52 and is supplied to the journal bearing 45, and is discharged to the outside from the outlet flow path. As a result, the drive unit 21 ensures that the stator 42 and rotor 44 are properly cooled by the refrigerant gas, and that the journal bearings 45, 46 and thrust bearing 47 function properly. The cooling gas that has cooled the drive unit 21 is returned to the compressor 22.
[0059] In the fourth embodiment, the refrigeration unit 10 uses gas bearings as journal bearings 45, 46 and thrust bearing 47 that support the rotating shaft 43 (drive shaft 24) in the compressor unit 11. Therefore, refrigerant gas can be used as the fluid that operates the journal bearings 45, 46 and thrust bearing 47.
[0060] [Fifth Embodiment] Figure 9 is a schematic diagram showing a refrigeration unit of the fifth embodiment. Components having the same functions as those in the first embodiment described above are denoted by the same reference numerals, and detailed explanations are omitted.
[0061] As shown in Figure 9, the housing 60 has a box-like shape and can be opened and closed by, for example, a lid (not shown). The refrigeration unit 10 (compressor unit 11, water-cooled heat exchanger 12, brine heat exchanger 13, regenerative heat exchanger 14) is arranged inside the housing 60.
[0062] The housing 60 has a base 62 positioned on an internal shelf 61. The housing 60 is movable via rails (not shown) on the shelf 61 and the base 62 rails. The refrigeration unit 10 is mounted on the base 62. Therefore, the refrigeration unit 10 can be pulled out of the housing 60 by moving the base 62.
[0063] In the fifth embodiment, the refrigeration unit 10 allows at least the compressor unit 11 to be pulled out from the housing 60 by a base 62. Therefore, the maintainability of the compressor unit 11 can be improved.
[0064] [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.
[0065] As shown in Figure 10, 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 is connected to an inverter 71. The inverter 71 includes a converter circuit (AC / DC converter) 72 and an inverter circuit 73. The inverter 71 is connected to a control device 74, and the control device 74 is connected to a power supply unit 75.
[0066] The power supply unit 75 supplies power to the control device 74. The control device 74 supplies power to the inverter 71 and the drive unit 21. The converter circuit 72 converts the AC from the power supply unit 75 to DC, and the inverter circuit 73 converts the DC back to AC. The inverter 71 changes the voltage and frequency of the electricity and outputs it to the drive unit 21.
[0067] Furthermore, the brine heat exchanger 13 is connected to pipes L3 and L41 through which low-pressure refrigerant gas flows, as well as to pipe L5 which supplies refrigerant gas to the object to be cooled 81. The brine heat exchanger 13 performs heat exchange between the low-pressure refrigerant gas flowing through pipes L3 and L41 and the refrigerant gas flowing through pipe L5. Here, the object to be cooled 81 is, for example, semiconductor manufacturing equipment or inspection equipment. Note that a heat exchanger may be placed between the brine heat exchanger 13 and the object to be cooled 81.
[0068] A temperature sensor 82 is provided to measure the temperature of the refrigerant gas flowing through the piping L3 upstream (or downstream piping L41) of the brine heat exchanger 13. The temperature sensor 82 is connected to a control device 74. The control device 74 controls the rotation speed of the drive unit 21 via an inverter 71 based on the temperature of the refrigerant gas measured by the temperature sensor 82. That is, the control device 74 adjusts the rotation speed of the motor in the drive unit 21 so that the temperature of the refrigerant gas at the inlet (or 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 82. In this case, if the temperature of the refrigerant gas measured by the temperature sensor 82 is higher than the optimal temperature, the rotation speed of the motor in the drive unit 21 is increased.
[0069] The refrigeration unit 10 of the sixth embodiment is equipped with a temperature sensor 82 that measures the temperature of the refrigerant gas flowing through pipes L3 and L41, and the control device 74 controls the rotation speed of the drive unit 21 based on the temperature of the refrigerant gas measured by the temperature sensor 82. As a result, the temperature of the refrigerant gas supplied to the object to be cooled 81 can be adjusted to the optimal temperature.
[0070] [Effects of this Embodiment] The refrigeration unit according to the first embodiment includes a compressor unit 11 having a compressor 22 and an expander 23 that are driven and connected to a drive shaft 24 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 as low-pressure refrigerant gas; and a regenerative heat exchanger 14 that performs heat exchange between the low-pressure refrigerant gas sent from the water-cooled heat exchanger 12 to the expander 23 and the used low-pressure refrigerant gas returned to the compressor 22. The water-cooled heat exchanger 12 has a pipe (inlet pipe) L1 connected to the lower part in the vertical direction to which refrigerant gas is supplied from the compressor 22, and a pipe (outlet pipe) L21 connected to the upper part in the vertical direction to which refrigerant gas is discharged. Part of the pipe L1 is positioned vertically below the central axis O1 of the rotation shaft which is arranged horizontally in the compressor 22.
[0071] According to the first embodiment of the refrigeration unit, when the refrigeration units 10, 10A, and 10B are in operation, in the low-temperature region, the moisture contained in the air freezes as the outside air is cooled, and ice forms on the outer surfaces of the expander 23, brine heat exchanger 13, and piping L22, L3, and L41. When the refrigeration units 10, 10A, and 10B stop operating, the melted ice drains into the drain pan 35 and is stored there. When the refrigeration unit 10 is restarted, the heat from piping L1 in the high-temperature region heats and evaporates the drain stored in the drain pan 35, reducing the amount of drain. This eliminates the need to drain the drain separately, and the generated drain can be properly handled. In addition, as heat is absorbed by the drain, the temperature of the refrigerant gas flowing inside piping L1 decreases, improving the cooling efficiency.
[0072] The refrigeration unit according to the second embodiment is the same as the refrigeration unit according to the first embodiment, further wherein a portion of the piping L1 is positioned vertically below the compressor unit 11. By positioning the piping L1 below the compressor unit 11, the condensate stored in the drain pan 35 can be efficiently heated by the heat from the piping L1.
[0073] The third embodiment of the refrigeration unit is a refrigeration unit according to the first or second embodiment, wherein a portion of the piping L1 is positioned vertically below the piping L42 that returns refrigerant gas to the compressor 22. By positioning piping L1 below piping L42, the condensate stored in the drain pan 35 can be efficiently heated by the heat from piping L1.
[0074] The refrigeration unit according to the fourth embodiment is a refrigeration unit according to any one of the first to third embodiments, further comprising a water-cooled heat exchanger 12, the inlet portion 12a to which the piping L1 is connected is positioned vertically below the central axis O1 of the rotation axis of the compressor 22. By positioning the piping L1 below the inlet portion 12a of the water-cooled heat exchanger 12, the drain stored in the drain pan 35 can be efficiently heated by the heat of the piping L1.
[0075] The fifth embodiment of the refrigeration unit is a refrigeration unit according to any one of the first to fourth embodiments, and further includes drain pans 35, 35A positioned below the compressor unit 11, the water-cooled heat exchanger 12, and the regenerative heat exchanger 14. This allows the drain descending from the compressor unit 11, the regenerative heat exchanger 14, etc., to be properly received by the drain pans 35, 35A.
[0076] The refrigeration unit according to the sixth embodiment is a refrigeration unit according to any one of the first to fifth embodiments, and furthermore, the compressor unit 11 is positioned vertically below the regenerative heat exchanger 14. This makes it possible to miniaturize the device.
[0077] The seventh embodiment of the refrigeration unit is a refrigeration unit according to any one of the first to sixth 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 a portion of the piping L1 is positioned vertically below the lower surface of the brine heat exchanger 13. This suppresses contact between the brine heat exchanger 13 and the drain stored in the drain pans 35 and 35A, thereby suppressing a decrease in performance.
[0078] The refrigeration unit according to the eighth embodiment is a refrigeration unit according to the seventh embodiment, further comprising a water-cooled heat exchanger 12 and a brine heat exchanger 13 arranged adjacent to each other along the width direction, and a drain pan 35A located below the compressor unit 11, the water-cooled heat exchanger 12, the brine heat exchanger 13 and the regenerative heat exchanger 14, wherein the drain pan 35A is inclined vertically upward on the side where the brine heat exchanger 13 is located. This allows the drain that falls into the drain pan 35A to flow into the horizontal section 35a for storage, and the heat from the piping L1 in the high-temperature region heats and evaporates the drain stored in the horizontal section 35a of the drain pan 35, thereby efficiently reducing the amount of drain stored in the drain pan 35A.
[0079] The refrigeration unit according to the ninth embodiment is a refrigeration unit according to the seventh or eighth embodiment, further comprising a regenerative heat exchanger 14 positioned opposite the water-cooled heat exchanger 12 and the brine heat exchanger 13 in the depth direction, with the side on which the brine heat exchanger 13 is located inclined downward in the vertical direction. As a result, the drain from the end of the regenerative heat exchanger 14 descends from the end on the brine heat exchanger 13 side and falls into the drain pan 35A, thereby suppressing the drain descending from the end of the regenerative heat exchanger 14 from adhering to the drive unit 21 of the compressor unit 11, and improving the reliability of the compressor unit 11.
[0080] The refrigeration unit according to the tenth embodiment is a refrigeration unit according to any one of the first to ninth embodiments, and furthermore, the piping L42 that returns refrigerant gas from the regenerative heat exchanger 14 to the compressor 22, the piping L1 that sends high-pressure refrigerant gas from the compressor 22 to the water-cooled heat exchanger 12, and the piping L21 that sends refrigerant gas from the water-cooled heat exchanger 12 to the regenerative heat exchanger 14 are made of rubber. By using rubber piping, the assembly of various components can be made easier and assembly efficiency can be improved.
[0081] The refrigeration unit according to the eleventh embodiment is a refrigeration unit according to any one of the first to tenth embodiments, further comprising: a housing 41 having a stator 42 with a cylindrical shape on its inner circumference; a rotating shaft 43 having a rotor 44 disposed inside the housing 41 and facing the stator 42; journal bearings 45, 46 and thrust bearing 47 composed of gas bearings that rotatably support the rotating shaft 43; and a gas supply path 55 that supplies high-pressure refrigerant gas compressed by a compressor 22 or low-pressure refrigerant gas from which expansion energy has been recovered by an expander 23 to the journal bearings 45, 46 and thrust bearing 47. By supplying refrigerant gas to the refrigerant gas flow path 50 of the drive unit 21 via the gas supply path 55, the journal bearings 45, 46 and thrust bearing 47 can be made to function properly with the refrigerant gas.
[0082] The 12th embodiment of the refrigeration unit is a refrigeration unit according to any one of the first to 11th embodiments, further comprising a compressor unit 11, a water-cooled heat exchanger 12, and a regenerative heat exchanger 14, all of which are arranged inside the housing 60. At least the compressor unit 11 is supported by a movable base 63 and can be pulled out from the housing 60. This improves the maintainability of the refrigeration unit 10 (compressor unit 11).
[0083] The refrigeration unit according to the 13th embodiment is a refrigeration unit according to any one of the first to tenth embodiments, and further includes a temperature sensor 82 provided in the piping (cooling path) L3 that sends the low-pressure refrigerant gas, from which the expansion energy has been recovered by the expander 23, to the object to be cooled for cooling, and measures the temperature of the refrigerant gas, and a control device 74 that controls the rotation speed of the drive device 21 based on the temperature of the refrigerant gas measured by the temperature sensor 82. 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] 10, 10A, 10B 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 35 Drain Pan 35a Horizontal Section 35b Frame Section 35c Inclined Section 41 Housing 42 Stator 43 Rotating Shaft 44 Rotor 45, 46 Journal Bearings (Gas Bearings) 47 Thrust Bearings (Gas Bearings) 48 Compressor Wheel 49 Turbine Wheel 50 Refrigerant Gas Flow Path 51 Inlet Flow Path 52 Axial Flow Path 55 Gas Supply Path 60 Housing 61 Shelf 62 Base 71 Inverter 72 Converter Circuit 73 Inverter Circuit 74 Control Device 75 Power Supply Unit 81 Object to be cooled 82 Temperature sensors 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 and connected to the 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 as low-pressure refrigerant gas; and a regenerative heat exchanger that performs heat exchange between the low-pressure refrigerant gas sent from the first cooler to the expander and the used low-pressure refrigerant gas returned to the compressor, wherein the first cooler has an inlet pipe connected to its lower vertical end for supplying refrigerant gas from the compressor, and an outlet pipe connected to its upper vertical end for discharging refrigerant gas, and a portion of the inlet pipe is positioned vertically below the central axis of the rotating shaft of the compressor which is arranged horizontally.
2. The refrigeration unit according to claim 1, wherein a portion of the inlet piping is positioned vertically below the compressor unit.
3. The refrigeration unit according to claim 1, wherein a portion of the inlet piping is positioned vertically below the piping that returns refrigerant gas to the compressor.
4. The refrigeration unit according to claim 1, wherein the inlet portion of the first cooler to which the inlet piping is connected is positioned vertically below the central axis of the rotation shaft of the compressor.
5. The refrigeration unit according to claim 1, further comprising a drain pan positioned below the compressor unit, the first cooler, and the regenerative heat exchanger.
6. The refrigeration unit according to claim 1, wherein the compressor unit is positioned vertically below the regenerative heat exchanger.
7. The refrigeration unit according to claim 1, further comprising a second cooler which 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, wherein the second cooler is a brine cooler which cools brine with low-pressure refrigerant gas from which expansion energy has been recovered by the expander, and a portion of the inlet piping is positioned vertically below the lower surface of the brine cooler.
8. The refrigerator unit according to claim 7, wherein the first cooler and the brine cooler are arranged adjacent to each other along the width direction, and the unit has a drain pan located below the compressor unit, the first cooler, the brine cooler and the regenerative heat exchanger, the drain pan being inclined vertically upward on the side where the brine cooler is located.
9. The refrigeration unit according to claim 8, wherein the regenerative heat exchanger is positioned opposite the first cooler and the brine cooler in the depth direction, and the side on which the brine cooler is located is inclined downward in the vertical direction.
10. The refrigeration unit according to claim 1, wherein the piping that supplies refrigerant gas from the regenerative heat exchanger to the compressor, the piping that supplies refrigerant gas from the compressor to the first cooler, and the piping that supplies refrigerant gas from the first cooler to the regenerative heat exchanger are made of rubber.
11. 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 journal bearing and a thrust bearing composed of gas bearings that rotatably support the rotating shaft, and a gas supply path that supplies refrigerant gas compressed by the compressor or refrigerant gas from which expansion energy has been recovered by the expander to the journal bearing and the thrust bearing.
12. The refrigeration unit according to claim 1, wherein the compressor unit, the first 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.
13. The refrigeration unit according to claim 1, further comprising: a temperature sensor provided in a cooling path that sends the low-pressure refrigerant gas, from which the expansion energy has been recovered by the expander, to an object to be cooled for cooling, and measuring the temperature of the refrigerant gas; and a control device that controls the rotational speed of the drive unit based on the temperature of the refrigerant gas measured by the temperature sensor.