Compressor for cryogenic refrigerator

Abstract

The utility model provides a heat exchanger configuration capable of reducing the occupied space of a heat exchanger in a compressor for a cryogenic refrigerator. A compressor (12) for a cryogenic refrigerator is provided with: a compressor housing (24); and a double-pipe heat exchanger (22) which is housed in the compressor housing (24) and cools the compressor (12). The double-pipe heat exchanger (22) is provided with a double pipe (28) disposed along at least one surface of the compressor housing (24). The sleeve (28) can be bent in a spiral shape along at least one surface of the compressor frame (24). The sleeve (28) can be bent along at least two sides of at least one face of the compressor frame (24) adjacent to each other.

Description

[0001] This application claims priority based on Japanese Patent Application No. 2023-101014 filed on June 20, 2023. The entire contents of this Japanese application are incorporated herein by reference. Technical Field

[0002] The utility model relates to a compressor for an ultra-low temperature refrigerator. Background Art

[0003] Typically, a cryogenic refrigerator such as a Gifford-McMahon (GM) refrigerator includes a compressor for supplying high-pressure refrigerant gas to a cold head. The compressor includes components such as a compressor body, an oil separator, an adsorber, a storage tank, and a control device.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2001-74326

[0005] In addition to the above-mentioned components, the compressor for ultra-low temperature refrigerators is usually provided with a heat exchanger for cooling the compressor. These components of the compressor are accommodated in the compressor frame. In previous designs, the heat exchanger occupies a relatively large space in the compressor frame. Therefore, when pursuing the miniaturization of the compressor, the heat exchanger may become a factor that hinders it. Summary of the invention

[0006] One of the exemplary purposes of an embodiment of the present invention is to provide a heat exchanger configuration capable of reducing the space occupied by the heat exchanger in a compressor for a cryogenic refrigerator.

[0007] According to one embodiment of the present invention, a compressor for a cryogenic refrigerator includes: a compressor frame; and a shell and tube heat exchanger housed in the compressor frame and cooling the compressor. The shell and tube heat exchanger includes a shell arranged along at least one surface of the compressor frame.

[0008] According to the utility model, a heat exchanger configuration is provided which can reduce the space occupied by the heat exchanger in a compressor for a super-low temperature refrigerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a diagram schematically showing a cryogenic refrigerator according to an embodiment.

[0010] Figure 2 It is a schematic perspective view showing the appearance of a compressor according to an embodiment.

[0011] Figure 3 It is a schematic perspective view showing the internal device arrangement of the compressor according to the embodiment.

[0012] Figure 4 It is a schematic front view of the heat exchanger according to the embodiment.

[0013] Figure 5 (a) is a schematic plan view showing the arrangement of devices in a compressor according to an embodiment. Figure 5 (b) is a schematic plan view showing the arrangement of devices in a compressor according to a comparative example.

[0014] In the figure: 10 - ultra-low temperature refrigerator, 12 - compressor, 22 - heat exchanger, 24 - compressor frame, 24b - back panel, 26a - back outer frame, 28 - casing. DETAILED DESCRIPTION

[0015] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and the accompanying drawings, the same or equivalent constituent elements, components and processes are marked with the same symbols, and repeated descriptions are appropriately omitted. For the convenience of explanation, the scale and shape of each part are appropriately set in each of the accompanying drawings, and unless otherwise specified, they are not interpreted as limiting. The embodiments are illustrative and do not limit the scope of the present invention in any way. All the features or their combinations described in the embodiments are not necessarily the essence of the invention.

[0016] Figure 1 1 is a diagram schematically showing a cryogenic refrigerator 10 according to an embodiment of the present invention. The cryogenic refrigerator 10 is used to perform cryogenic cooling on an object or a medium. For example, the cryogenic refrigerator 10 can be used as a cooling source for a superconducting magnet device. The superconducting magnet device can be mounted on a strong magnetic field utilizing device as a magnetic field source of, for example, a single crystal pulling device, an NMR (Nuclear Magnetic Resonance) system, an MRI (Magnetic Resonance Imaging) system, an accelerator such as a cyclotron, a high energy physics system such as a nuclear fusion system, or other strong magnetic field utilizing devices (not shown), thereby generating a strong magnetic field required by the device.

[0017] The cryogenic refrigerator 10 includes a compressor 12 and a cold head 14. The compressor 12 is configured to recover the refrigerant gas of the cryogenic refrigerator 10 from the cold head 14, and to supply the refrigerant gas to the cold head 14 again after pressurizing the recovered refrigerant gas. The compressor 12 is also referred to as a compressor unit. The cold head 14 is also referred to as an expander, and has a room temperature portion 14a and a low temperature portion 14b (also referred to as a cooling stage). The refrigerant gas is also referred to as a working gas, and helium is usually used, but other suitable gases may also be used. The refrigeration cycle of the cryogenic refrigerator 10 is constituted by the compressor 12 and the cold head 14, thereby cooling the low temperature portion 14b to a desired ultra-low temperature. The low temperature portion 14b can cool a cooled object such as a superconducting magnet, for example.

[0018] As an example, the cryogenic refrigerator 10 is a single-stage or two-stage Gifford-McMahon (GM) refrigerator, but may also be a pulse tube refrigerator, a Stirling refrigerator, or other types of cryogenic refrigerators. The cold head 14 has different structures depending on the type of the cryogenic refrigerator 10, but the compressor 12 has the following structure regardless of the type of the cryogenic refrigerator 10.

[0019] In addition, usually, the pressure of the refrigerant gas supplied from the compressor 12 to the cold head 14 and the pressure of the refrigerant gas recovered from the cold head 14 to the compressor 12 are both much higher than the atmospheric pressure, and can be respectively referred to as the first high pressure and the second high pressure. For the sake of convenience, the first high pressure and the second high pressure are respectively referred to as the high pressure and the low pressure. Typically, the high pressure is, for example, 2 to 3 MPa. The low pressure is, for example, 0.5 to 1.5 MPa, and the low pressure is, for example, about 0.8 MPa.

[0020] The compressor 12 is an oil-lubricated compressor for a cryogenic refrigerator, and includes a compressor body 16, a refrigerant gas pipeline 18, and an oil circulation pipeline 20. Figure 1 In the figure, for ease of understanding, the refrigerant gas pipeline 18 is indicated by a solid line, and the oil circulation pipeline 20 is indicated by a dotted line. The compressor 12 includes a compressor housing 24 that accommodates components of the compressor 12, such as the compressor body 16, the refrigerant gas pipeline 18, and the oil circulation pipeline 20.

[0021] The compressor body 16 is configured to compress the refrigerant gas sucked from the suction port thereof and discharge it from the discharge port. In the compressor body 16, oil is used for cooling and lubrication, and the sucked refrigerant gas is directly exposed to the oil in the compressor body 16. Therefore, the refrigerant gas is sent from the discharge port in a state mixed with a small amount of oil.

[0022] The compressor body 16 may be, for example, a vortex pump, a rotary pump, or other pumps that increase the pressure of the refrigerant gas. The compressor body 16 may be configured to discharge a constant refrigerant gas flow rate. Alternatively, the compressor body 16 may be configured to make the discharged refrigerant gas flow rate variable. The compressor body 16 is sometimes also referred to as a compression chamber.

[0023] The refrigerant gas pipeline 18 includes a discharge port 30, a suction port 31, a discharge flow path 32, and a suction flow path 33. The discharge port 30 is an outlet of the refrigerant gas provided in the compressor frame 24 in order to deliver the refrigerant gas pressurized to a high pressure by the compressor body 16 from the compressor 12, and the suction port 31 is an inlet of the refrigerant gas provided in the compressor frame 24 in order to recover the low-pressure refrigerant gas into the compressor 12. The discharge flow path 32 and the suction flow path 33 are accommodated in the compressor frame 24. The discharge port of the compressor body 16 is connected to the discharge port 30 through the discharge flow path 32, and the suction port 31 is connected to the suction port of the compressor body 16 through the suction flow path 33.

[0024] The refrigerant gas pipeline 18 is connected to the cold head 14. The room temperature portion 14a of the cold head 14 is provided with a high pressure port 40 and a low pressure port 41. The high pressure port 40 is connected to the discharge port 30 via a high pressure pipe 42, and the low pressure port 41 is connected to the suction port 31 via a low pressure pipe 43.

[0025] An oil separator 34 and an adsorber 35 are provided on the discharge flow path 32. The purpose of the oil separator 34 is to separate the oil mixed into the refrigerant gas when the refrigerant gas passes through the compressor body 16. The purpose of the adsorber 35 is to remove, by adsorption, the oil or other pollutants remaining in the refrigerant gas, such as vaporized oil, from the refrigerant gas. The oil separator 34 and the adsorber 35 are connected in series. On the discharge flow path 32, the oil separator 34 is arranged on the compressor body 16 side, and the adsorber 35 is arranged on the discharge port 30 side.

[0026] An oil return line 21 is provided to connect the oil separator 34 to the compressor body 16. The oil recovered by the oil separator 34 can be returned to the compressor body 16 through the oil return line 21. A filter for removing dust contained in the oil separated by the oil separator 34 and a throttle hole for controlling the amount of oil returned to the compressor body 16 may be provided on the way of the oil return line 21.

[0027] On the other hand, an accumulator 36 is provided in the suction flow path 33. The accumulator 36 is set to have a capacity for removing pulsation included in the low-pressure refrigerant gas returning from the cold head 14 to the compressor 12.

[0028] In addition, a bypass valve 38 is provided on the refrigerant gas pipeline 18 to connect the discharge flow path 32 to the suction flow path 33 in a manner bypassing the compressor body 16. As an example, the bypass valve 38 branches from the discharge flow path 32 between the oil separator 34 and the adsorber 35 and is connected to the suction flow path 33 between the compressor body 16 and the accumulator 36. The bypass valve 38 is provided for the purpose of controlling the refrigerant gas flow rate and / or balancing the pressure between the discharge flow path 32 and the suction flow path 33 when the compressor 12 is stopped.

[0029] The oil circulation pipeline 20 connects the oil outlet of the compressor body 16 to the oil inlet so that the oil flowing out of the compressor body 16 returns to the compressor body 16. The oil circulation pipeline 20 may be provided with a throttle hole for controlling the oil flow rate flowing through the inside. In addition, the oil circulation pipeline 20 may be provided with a filter for removing dust contained in the oil.

[0030] The compressor 12 further includes a heat exchanger 22 that is housed in a compressor housing 24 and cools the compressor 12. The heat exchanger 22 includes a refrigerant gas cooler 22a that cools the refrigerant gas line 18 by exchanging heat between the refrigerant gas and the cooling medium, and an oil cooler 22b that cools the oil circulation line 20 by exchanging heat between the oil and the cooling medium.

[0031] The refrigerant gas cooler 22a is provided between the compressor body 16 and the oil separator 34 on the discharge flow path 32, and cools the high-pressure refrigerant gas heated by the compression heat generated by the compression of the refrigerant gas in the compressor body 16. The refrigerant gas cooler 22a cools the refrigerant gas by heat exchange between the refrigerant gas and the cooling medium. The cooled refrigerant gas is purified in the oil separator 34 and the adsorber 35. In addition, the oil cooler 22b cools the oil by heat exchange between the oil flowing out from the oil outlet of the compressor body 16 to the oil circulation pipe 20 and the cooling medium. The cooled oil returns to the compressor body 16 from the oil inlet of the compressor body 16. The cooling medium is supplied to the compressor 12 from the outside through the cooling medium inlet 44, and is discharged from the cooling medium outlet 45 to the outside of the compressor 12 after passing through the refrigerant gas cooler 22a and the oil cooler 22b. The cooling medium is a cooling liquid, for example, water. Thus, the compression heat generated in the compressor body 16 is discharged together with the cooling medium to the outside of the compressor 12. In addition, the cooling medium may be cooled by, for example, a chiller (not shown) and then supplied again.

[0032] In this embodiment, the heat exchanger 22 is a shell-and-tube heat exchanger. Therefore, the heat exchanger 22 has an outer tube and an inner tube inserted into the outer tube. The cooling medium is supplied to one of the outer tube and the inner tube, and the fluid to be cooled is supplied to the other tube, thereby enabling heat exchange between the cooling medium and the target fluid to cool the fluid. For example, in the refrigerant gas cooler 22a, cooling water can be supplied to the outer tube, and refrigerant gas can be supplied to the inner tube. In the oil cooler 22b, cooling water can be supplied to the outer tube, and oil can be supplied to the inner tube.

[0033] In addition, the compressor frame 24 may also contain a control device 50 for controlling the cryogenic refrigerator 10. The control device 50 may include a control circuit, which is configured to receive outputs from various sensors provided on the cryogenic refrigerator 10 and control various devices of the cryogenic refrigerator 10 according to the sensor outputs. The sensors may include, for example, a refrigerant gas temperature sensor and a refrigerant gas pressure sensor provided on the refrigerant gas pipeline 18, an oil temperature sensor provided on the oil circulation pipeline 20, and a cooling temperature sensor provided on the low temperature portion 14b of the cold head 14. The devices controlled according to the sensor outputs may include, for example, a compressor motor driving the compressor body 16, a bypass valve 38, and a cold head motor driving the cold head 14. The control device 50 may include a compressor inverter for controlling the rotation speed of the compressor motor and / or a cold head inverter for controlling the rotation speed of the cold head motor.

[0034] During the operation of the ultra-low temperature refrigerator 10, the refrigerant gas is supplied from the compressor 12 to the cold head 14, and the periodic volume change of the expansion space of the refrigerant gas in the cold head 14 and the pressure change of the refrigerant gas in the expansion space synchronously therewith constitute a refrigeration cycle (for example, a GM cycle), and the low temperature portion 14b of the cold head 14 is cooled to a desired ultra-low temperature. For example, in the case where the cold head 14 is a two-stage type, the first stage cooling stage is cooled to a first cooling temperature in the range of about 30K to about 80K, for example, and the second stage cooling stage is cooled to a second cooling temperature lower than the first cooling temperature, for example, to 1K to 20K. The second cooling temperature can be a liquid helium temperature of about 4.2K or a temperature lower than it.

[0035] The refrigerant gas recovered from the cold head 14 to the compressor 12 flows from the low-pressure port 41 through the low-pressure pipe 43 into the suction port 31 of the compressor 12. The refrigerant gas is recovered to the suction port of the compressor body 16 after passing through the storage tank 36 on the suction flow path 33. The refrigerant gas is compressed and pressurized by the compressor body 16. At this time, the temperature of the refrigerant gas is increased based on the compression heat. The refrigerant gas sent out from the discharge port of the compressor body 16 is cooled in the refrigerant gas cooler 22a of the heat exchanger 22, and leaves the compressor 12 from the discharge port 30 after passing through the oil separator 34 and the adsorber 35. The refrigerant gas is supplied to the inside of the cold head 14 via the high-pressure pipe 42 and the high-pressure port 40.

[0036] Figure 2 It is a schematic perspective view showing the appearance of the compressor 12 according to the embodiment. Figure 3 It is a schematic perspective view showing the internal device arrangement of the compressor 12 according to the embodiment. Figure 2 and Figure 3 Each of them is a perspective view when the compressor 12 is viewed from the rear. Figure 3 2 shows a state where some panels of the compressor housing 24 are removed in order to illustrate the arrangement of internal devices of the compressor 12 .

[0037] like Figure 2 As shown, the compressor frame 24 of the compressor 12 is in the shape of a rectangular parallelepiped with six faces, that is, it has a front panel 24a, a back panel 24b, a top panel 24c, a bottom panel 24d, and two side panels 24e and 24f on the left and right. The back panel 24b faces the side opposite to the front panel 24a. Between the front panel 24a and the back panel 24b, the top panel 24c is arranged at the top, the bottom panel 24d is arranged at the bottom, and the side panels 24e and 24f are arranged on the left and right sides.

[0038] The front panel 24a may be configured to provide a user interface and piping connection. Therefore, an operation panel 25 for receiving input from a user of the cryogenic refrigerator 10 for controlling the cryogenic refrigerator 10 and / or for displaying information related to the cryogenic refrigerator 10 may be provided on the front surface of the front panel 24a. A control device 50 may be mounted on the front panel 24a, for example, the control device 50 may be installed on the back of the front panel 24a. Figure 2 and Figure 3 In the figure, the front panel 24a is not shown because it faces the back side, but the discharge port 30, the suction port 31, the cooling medium inlet 44 and the cooling medium outlet 45 may be provided on the front panel 24a.

[0039] Casters 52 may be mounted on the bottom panel 24d to facilitate movement or transportation of the compressor 12.

[0040] like Figure 3 As shown, the compressor frame 24 has a frame structure 26 that supports the panel and bears the structural strength. The panel is detachably mounted on the frame structure 26. Figure 2 As shown, when the panel is mounted on the frame structure 26, the equipment in the compressor 12 is covered by the panel. The panel can be mounted on the frame structure 26 by a suitable method such as screw fixing. When the panel is removed from the frame structure 26, the user or operator can easily access the equipment in the compressor 12 from the opening of the frame structure 26, and the maintenance work or manufacturing work of the compressor 12 can be effectively performed.

[0041] For example, a rectangular back outer frame 26a is provided on the back side of the compressor frame 24, which is provided in a manner to surround the back side and constitutes a part of the frame structure 26. The four sides of the rectangular shape of the back panel 24b are respectively detachably mounted on the back outer frame 26a. The upper ends of the back outer frame 26a are connected to the upper ends of the front panel 24a through two side frames 26b, and the lower part of the back outer frame 26a is connected to the rear edge of the bottom panel 24d. In addition, the lower edge of the front panel 24a is connected to the front edge of the bottom panel 24d. The four sides of the top panel 24c are detachably mounted on the upper part of the back outer frame 26a and the front panel 24a and the two side frames 26b. The four sides of the side panels 24e and 24f are detachably mounted on the back outer frame 26a, the side of the front panel 24a, the side frames 26b and the bottom panel 24d.

[0042] As described above, the main components of the compressor 12, such as the compressor body 16, the heat exchanger 22, the oil separator 34, the adsorber 35, the tank 36, and the control device 50, are accommodated in the compressor frame 24. The oil separator 34, the adsorber 35, that is, the tank 36 are arranged on the bottom panel 24d in a manner close to the side panel 24e on one side, and are thus arranged in the compressor frame 24. The adsorber 35, the tank 36, and the oil separator 34 are arranged in sequence from the front panel 24a toward the back panel 24b. In addition, the compressor body 16 and the control device 50 are arranged in the compressor frame 24 in a manner close to the other side panel 24f. As described above, the control device 50 can be installed on the front panel 24a, and the compressor body 16 is arranged on the bottom panel 24d between the control device 50 and the back panel 24b.

[0043] The heat exchanger 22 has a sleeve 28 disposed along at least one surface of the compressor housing 24 (in this embodiment, the back surface of the compressor housing 24). The sleeve 28 is supported by the back outer frame 26a. When the back panel 24b is mounted on the back outer frame 26a, the heat exchanger 22 is covered by the back panel 24b.

[0044] Figure 4 It is a schematic front view of the heat exchanger 22 according to the embodiment. Figure 4 2 shows a state where the heat exchanger 22 and the rear outer frame 26a are viewed from the inside of the compressor 12 (ie, from the inside of the compressor housing 24) with the rear panel 24b removed.

[0045] like Figure 3 and Figure 4 As shown in FIG. 2 , the sleeve 28 includes a first portion 28a and a second portion 28b. The first portion 28a of the sleeve 28 is Figure 1 The heat exchanger 22 shown functions as a refrigerant gas cooler 22a, and the second portion 28b functions as an oil cooler 22b.

[0046] like Figure 4 As shown, a refrigerant gas inlet 54a and a first cooling medium outlet 56b are provided at one end of the first portion 28a of the sleeve 28, and a refrigerant gas outlet 54b and a first cooling medium inlet 56a are provided at the other end. Figure 1 As shown, the refrigerant gas inlet 54a is connected to the discharge port of the compressor body 16, and the high-temperature and high-pressure refrigerant gas pressurized in the compressor body 16 flows into the refrigerant gas cooler 22a (i.e., the first portion 28a) through the refrigerant gas inlet 54a. The cooling medium (such as cooling water as described above) supplied to the compressor 12 from the cooling medium inlet 44 flows into the refrigerant gas cooler 22a from the first cooling medium inlet 56a, and flows out from the first cooling medium outlet 56b after cooling the refrigerant gas by heat exchange. The refrigerant gas outlet 54b is connected to the oil separator 34, and the cooled high-pressure refrigerant gas is supplied to the oil separator through the first cooling medium outlet 56b.

[0047] The first portion 28a of the sleeve 28 is bent along at least two sides adjacent to each other on the back side of the compressor frame 24, and in this embodiment, is bent along three sides adjacent to each other. Figure 3 and Figure 4 As shown, the first portion 28a is bent into a substantially C-shape along the upper and side edges of the rear outer frame 26a and the rear edge of the bottom panel 24d. Thus, the first portion 28a is disposed so as to leave a central portion of the rear surface of the compressor frame 24 vacant.

[0048] Furthermore, an oil inlet 58a and a second cooling medium outlet 60b are provided at one end of the second portion 28b of the sleeve 28, and an oil outlet 58b and a second cooling medium inlet 60a are provided at the other end. Figure 1 As shown, the oil inlet 58a is connected to the oil outlet of the compressor body 16, and the oil flowing out of the compressor body 16 flows into the oil cooler 22b (that is, the second portion 28b) through the oil inlet 58a. Figure 4As shown, the second cooling medium inlet 60a is connected to the first cooling medium outlet 56b, and the cooling medium flows from the first part 28a to the second part 28b, and flows out from the second cooling medium outlet 60b after heat exchange with the cooling oil. Figure 1 As shown, the second cooling medium outlet 60b is connected to the cooling medium discharge port 45, and the cooling medium for cooling the refrigerant gas and the oil is discharged from the compressor 12 via the cooling medium discharge port 45. The oil outlet 58b is connected to the oil inlet of the compressor body 16, and the cooled oil returns to the compressor body 16.

[0049] The second portion 28b of the sleeve 28 is spirally bent along the back side of the compressor frame 24. The second portion 28b is arranged inside the first portion 28a on the back side of the compressor frame 24. In this way, the second portion 28b is arranged to leave the center portion of the back side of the compressor frame 24 empty. An opening portion 62 in which the sleeve 28 is not arranged is formed inside the second portion 28b (i.e., the center portion of the back side of the compressor frame 24).

[0050] The sleeve 28 is supported by the back outer frame 26a. Figure 4 As shown, the sleeve 28 can be fixed to the back outer frame 26a using a support member 64. In this example, two support members 64 are respectively installed on the left and right sides of the back outer frame 26a. One end of the support member 64 is installed on the back outer frame 26a by a suitable method such as screw fixing, and the other end extends horizontally toward the opening 62. A hole for inserting the sleeve 28 is formed on the support member 64, and the sleeve 28 is inserted into the hole of the support member 64 and then installed on the support member 64 by a suitable method such as brazing.

[0051] Figure 5 (a) is a schematic plan view showing the arrangement of devices in the compressor 12 according to the embodiment. Figure 5 (b) is a schematic plan view showing the arrangement of devices in the compressor 112 according to the comparative example. Figure 5 (a) and (b) show a state where the top panel 24c is removed from the compressor frame 24. In addition, for the sake of convenience, the piping connecting the components of the compressor 12 is omitted in each figure.

[0052] As described above, the compressor 12 includes the compressor body 16, the heat exchanger 22, the oil separator 34, the adsorber 35, the storage tank 36, and the control device 50. Figure 5 As shown in (a), the compressor body 16 and the control device 50 are arranged in the half area between the front panel 24a and the back panel 24b of the compressor frame 24, and the oil separator 34, the adsorber 35 and the storage tank 36 are arranged in the other half area. The heat exchanger 22 is arranged along the back panel 24b.

[0053] On the other hand, Figure 5 In the conventional compressor 112 shown in (b), the compressor body 16, the heat exchanger 122 and the control device 50 are arranged in the half area between the front panel 24a and the back panel 24b of the compressor frame 24, and the oil separator 34, the adsorber 35 and the storage tank 36 are arranged in the other half area. The heat exchanger 122 is arranged between the compressor body 16 and the control device 50, and can be, for example, a heat sink type heat exchanger.

[0054] exist Figure 5 In the equipment configuration of the compressor 112 shown in (b), the heat exchanger 122 occupies a relatively large space between the compressor body 16 and the control device 50 in order to provide the desired cooling performance. Figure 5 As can be seen from the comparison between (a) and (b), the occupied space for the compressor body 16 and the control device 50 is limited.

[0055] In contrast, according to the implementation mode, Figure 5 As shown in (a), the heat exchanger 22 is arranged along at least one surface (for example, the back surface) of the compressor frame 24. In previous designs, the space adjacent to the surface of the compressor frame 24 was not used as a dead space. By using it to accommodate the heat exchanger 22, the occupied space of other equipment such as the compressor body 16 and the control device 50 can be expanded. Therefore, the degree of freedom of equipment configuration in the compressor 12 is increased, which is advantageous. In addition, in recent years, there has been a trend to require a large control device 50 to be installed on the compressor 12 in order to achieve a high degree of control. According to the embodiment, it is easy to cope with such requirements and fully ensure the installation space of the control device 50, which is advantageous.

[0056] Furthermore, according to an embodiment, the sleeve 28 of the heat exchanger 22 is bent along the outer periphery of the surface of the compressor frame 24. For example, as described above, the first part 28a is bent along at least two adjacent sides of the back side of the compressor frame 24, and the second part 28b is spirally bent along the back side of the compressor frame 24. By utilizing a bent tube of this shape, it is possible to suppress the increase in the occupied space of the heat exchanger 22 while easily lengthening the total length of the heat exchanger 22. In particular, compared with a fin-type heat exchanger that can be mounted on a conventional compressor, the heat exchanger 22 involved in the embodiment can reduce the occupied space. As described above, suppressing the increase in occupied space helps to increase the degree of freedom in the configuration of other equipment in the compressor 12. Lengthening the total length of the heat exchanger 22 helps to improve the cooling performance of the sleeve-type heat exchanger 22.

[0057] According to the embodiment, the heat exchanger 22 is configured to leave the central portion of the surface of the compressor frame 24 where the sleeve 28 is configured empty. Thus, an opening portion 62 where the sleeve 28 is not configured is formed in the central portion of the surface of the compressor frame 24. In the manufacturing process of the compressor 12 or in the maintenance operation of the compressor 12 at the site where the compressor 12 is used, the operator can easily access the equipment in the compressor 12 from the opening portion 62. For example, the implementation of manufacturing operations such as pipe welding and joint tightening or various maintenance operations (for example, replacement of consumables such as filters, replacement and repair of equipment such as failed sensors, etc.) can be performed through the opening portion 62. In this way, the configuration of the sleeve 28 leaving the central portion empty helps to improve the efficiency of the manufacturing and maintenance of the compressor 12.

[0058] Conventional compressors are designed in which the panels forming each surface of the compressor frame bear the structural strength, so the panels are thick and heavy. Therefore, it is not easy to install the panels during the manufacturing process or to remove the panels during maintenance, which is a reason for the reduced operability for operators.

[0059] In contrast, according to the embodiment, the compressor frame 24 has a frame structure 26 that bears the structural strength, so that each panel such as the back panel 24b mounted on the frame structure 26 can be thinned and lightened. This frame structure also helps to improve operability. In addition, the thinning of the panel also helps to ensure the storage space of the heat exchanger 22.

[0060] The present invention is described above based on the embodiments. Those skilled in the art should understand that the present invention is not limited to the above-mentioned embodiments, and various design changes and variations may exist, and such variations are also within the scope of the present invention. Various features described in one embodiment may also be applicable to other embodiments. The new embodiment generated by the combination has the effects of the combined embodiments.

[0061] In the above embodiment, the heat exchanger 22 is arranged along the back surface of the compressor housing 24, but this is only an example and the present invention is not limited thereto. The heat exchanger 22 may also be arranged along other surfaces (eg, top surface or side surface) of the compressor housing 24.

[0062] Furthermore, in the above embodiment, the case where the heat exchanger 22 is arranged only along a single surface (i.e., the back surface) of the compressor frame 24 is exemplified, but the heat exchanger 22 may also be arranged in other ways. For example, the heat exchanger 22 may be arranged along at least two surfaces (e.g., the back surface and the top surface, or the back surface and the side surface) of the compressor frame 24 that are adjacent to each other.

[0063] The curved shape of the sleeve 28 is not limited to the spiral shape. For example, the sleeve 28 may be bent along the surface of the compressor frame 24 in a zigzag manner.

[0064] The present invention has been described above based on the implementation method and using specific terms, but the implementation method only shows one aspect of the principle and application of the present invention. Without departing from the scope of the idea of ​​the present invention specified in the technical solution, the implementation method allows for a variety of modifications and configuration changes.

Claims

1. A compressor for a cryogenic refrigerator, characterized in that: have: compressor frame; and a shell-and-tube heat exchanger, which is contained in the compressor frame and cools the compressor, The double-tube heat exchanger includes a double-tube heat exchanger disposed along at least one surface of the compressor housing.

2. The compressor for a cryogenic refrigerator according to claim 1, characterized in that: The sleeve is spirally bent along the at least one surface of the compressor frame.

3. The compressor for ultra-low temperature refrigerator according to claim 2, characterized in that: The sleeve is arranged so as to leave a central portion of the at least one surface of the compressor frame.

4. The compressor for a cryogenic refrigerator according to claim 1, characterized in that: The sleeve is bent along at least two sides adjacent to each other of the at least one surface of the compressor frame.

5. The compressor for a cryogenic refrigerator according to claim 4, characterized in that: The sleeve is arranged so as to leave a central portion of the at least one surface of the compressor frame.

6. The compressor for a cryogenic refrigerator according to any one of claims 1 to 5, characterized in that: The at least one surface includes a rear surface of the compressor frame.

7. The compressor for a cryogenic refrigerator according to claim 6, characterized in that: The compressor housing includes: a rear outer frame provided to surround the rear surface and to support the casing; and a rear panel detachably mounted on the rear outer frame to cover the casing heat exchanger.

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