Cooling system
Patent Information
- Application Number
- PCT/JP2026/012388
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-26
- Filing Date
- 2026-03-26
- Publication Date
- 2026-10-01
Smart Images
Figure JP2026012388_01102026_PF_FP_ABST
Abstract
Description
Cooling system
[0001] The present invention relates to a cooling system that supplies a refrigerant to a rotation testing apparatus that rotates a test specimen.
[0002] Rotation testing apparatuses for testing a test specimen having a rotating body are known. The rotation testing apparatus is constituted, for example, by a motor. In a power test of the test specimen, for example, torque or rotation speed when the rotating body of the test specimen is driven to rotate by the motor of the rotation testing apparatus is measured.
[0003] When current flows through the coil of the motor to drive and rotate the motor, the coil generates heat. Various cooling methods for cooling the heat-generating coil are known. For example, Patent Document 1 discloses a rotating electric machine that supplies a liquid refrigerant to a stator coil. Further, in the rotating electric machine disclosed in Patent Document 1, a cooling gas or a liquid refrigerant is supplied to the stator coil.
[0004] Japanese Unexamined Patent Publication No. 2006-011641
[0005] By the way, in order to efficiently cool each component in a motor, refrigerants having different temperatures may be required depending on the configuration of the motor. For example, when supplying a refrigerant of lower temperature to the motor, it is necessary to provide a heat exchange device having higher heat exchange performance in a cooling system that supplies the refrigerant to the motor. However, generally, the size of a heat exchange device having high heat exchange performance becomes larger.
[0006] Therefore, for example, when a partial configuration of the motor requires a refrigerant of lower temperature, in order to lower the temperature of the entire refrigerant to the required temperature with a single heat exchange device, a larger heat exchange device with higher heat exchange performance is required. There is a demand for suppressing an increase in size of the heat exchange device.
[0007] An object of the present invention is to achieve, in a cooling system that supplies a refrigerant to a rotation testing apparatus that rotates a test specimen, a configuration capable of lowering the temperature of a part of the refrigerant to a lower temperature without increasing the size of each heat exchange device on a refrigerant circuit.
[0008] A cooling system according to one embodiment of the present invention is a system for supplying a refrigerant to a rotational test apparatus that rotates a test specimen. The cooling system includes a first refrigerant flow path connected to a refrigerant outlet of the rotational test apparatus, a second refrigerant flow path that supplies a portion of the refrigerant flowing through the first refrigerant flow path to a first refrigerant supply port of the rotational test apparatus, a third refrigerant flow path that supplies the remaining portion of the refrigerant flowing through the first refrigerant flow path to a second refrigerant supply port of the rotational test apparatus, and a plurality of heat exchange devices that perform heat exchange of the refrigerant supplied to the rotational test apparatus. The plurality of heat exchange devices include a first heat exchange device arranged on the first refrigerant flow path to perform heat exchange of the refrigerant flowing through the first refrigerant flow path, and a second heat exchange device arranged on the third refrigerant flow path to perform heat exchange of the refrigerant flowing through the third refrigerant flow path (first configuration).
[0009] In the above configuration, the refrigerant discharged from the refrigerant outlet of the rotational test apparatus passes through the first refrigerant flow path. The first refrigerant flow path branches into a second refrigerant flow path and a third refrigerant flow path at its other end. The refrigerant passing through the second refrigerant flow path flows into the first refrigerant supply port of the rotational test apparatus. The refrigerant passing through the third refrigerant flow path flows into the second refrigerant supply port of the rotational test apparatus.
[0010] Therefore, in the above configuration, a portion of the refrigerant that has undergone heat exchange by the first heat exchanger located in the first refrigerant flow path flows into the first refrigerant supply port of the rotational test device via the second refrigerant flow path, while the remainder flows into the third refrigerant flow path. Furthermore, the refrigerant that has flowed into the third refrigerant flow path undergoes further heat exchange by the second heat exchanger located in the third refrigerant flow path and flows into the second refrigerant supply port of the rotational test device.
[0011] For example, to lower the temperature of the refrigerant to a lower temperature, the size of the heat exchanger needs to be larger. In contrast, the above configuration allows the temperature of the remaining refrigerant to be lowered to a lower temperature, thus reducing the size of each heat exchanger in the refrigerant circuit compared to lowering the temperature of the entire refrigerant.
[0012] This allows some of the refrigerant to be cooled to a lower temperature without increasing the size of the heat exchangers in the refrigerant circuit.
[0013] In the first configuration, the first heat exchanger has a heat exchanger that performs heat exchange between the refrigerant and industrial water. The plurality of heat exchangers further include one or more heat exchangers arranged on the first refrigerant flow path to perform heat exchange of the refrigerant flowing in the first refrigerant flow path. The one or more heat exchangers are located on the side of the refrigerant flow direction relative to the first heat exchanger (second configuration).
[0014] According to the above configuration, in addition to the first heat exchanger, heat exchange of the refrigerant flowing in the first refrigerant flow path can be performed by one or more heat exchangers. For example, the refrigerant discharged from the first heat exchanger can be further cooled by one or more heat exchangers. Therefore, the refrigerant can be cooled to a desired temperature without increasing the size of the first heat exchanger. Also, the temperature of industrial water varies depending on the region or season. Even if there is variation in the temperature of the industrial water used for heat exchange in the first heat exchanger, the variation in temperature can be suppressed by heat exchange in one or more heat exchangers. For example, if the temperature of the industrial water is higher than average, the refrigerant can be further cooled by the heat exchanger. On the other hand, for example, if the temperature of the industrial water is lower than the temperature of the refrigerant to be supplied to the first refrigerant supply port, the refrigerant temperature can also be heated by the heat exchanger. This makes it possible to supply refrigerant with less temperature variation to the first refrigerant supply port of the rotational test apparatus.
[0015] In the second configuration described above, the first heat exchanger further comprises a suction pump for drawing the refrigerant from the test specimen, a storage tank for storing the refrigerant, and a discharge pump for discharging the refrigerant from the storage tank (third configuration).
[0016] According to the above configuration, the amount of refrigerant supplied to the rotational test apparatus can be adjusted by storing the refrigerant in a storage tank. This allows for the smooth supply of the desired amount of refrigerant to the rotational test apparatus.
[0017] In any one of the first to third configurations, the refrigerant is a lubricating oil. The cooling system supplies the refrigerant flowing into the first refrigerant supply port to the bearings of the rotational test device (fourth configuration).
[0018] According to the above configuration, a cooling system can be realized to cool the lubricating oil flowing to the bearings of the rotating test device.
[0019] In any one of the first to third configurations, the rotational test apparatus includes a motor having a coil. The cooling system supplies the refrigerant flowing into the second refrigerant supply port to the coil (fifth configuration).
[0020] The motor coil is a component that easily generates heat when the motor is driven. With the above configuration, a cooling system that can efficiently cool the coil can be realized by supplying a refrigerant at a lower temperature than the refrigerant supplied to the first refrigerant supply port to the second refrigerant supply port.
[0021] A cooling system according to one embodiment of the present invention includes: a first refrigerant flow path connected to the refrigerant outlet of a rotating test apparatus; a second refrigerant flow path that supplies a portion of the refrigerant flowing through the first refrigerant flow path to a first refrigerant supply port of the rotating test apparatus; a third refrigerant flow path that supplies the remaining portion of the refrigerant flowing through the first refrigerant flow path to the second refrigerant supply port of the rotating test apparatus; and a plurality of heat exchange devices that perform heat exchange of the refrigerant supplied to the rotating test apparatus. The plurality of heat exchange devices include a first heat exchange device arranged on the first refrigerant flow path to perform heat exchange of the refrigerant flowing through the first refrigerant flow path, and a second heat exchange device arranged on the third refrigerant flow path to perform heat exchange of the refrigerant flowing through the third refrigerant flow path.
[0022] This makes it possible to achieve a configuration in a cooling system that supplies refrigerant to a rotating test apparatus that rotates a test specimen, in which some of the refrigerant can be lowered to a lower temperature without increasing the size of the heat exchangers in the refrigerant circuit.
[0023] Figure 1 is a diagram showing the schematic configuration of a cooling system according to Embodiment 1 of the present invention. Figure 2 is a diagram showing the schematic configuration of a cooling system according to Embodiment 2 of the present invention. Figure 3 is a diagram showing the flow of refrigerant inside a rotating test apparatus. Figure 4 is a diagram showing the schematic configuration of a conventional cooling system.
[0024] Embodiments of the present invention will be described in detail below with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and their descriptions will not be repeated.
[0025] Furthermore, in the following explanation, the expressions "fixed," "connected," and "attached" (hereinafter referred to as "fixed, etc.") include not only cases where components are directly fixed to each other, but also cases where they are fixed to each other via other components. In other words, in the following explanation, the expression "fixed, etc." includes both direct and indirect fixing of components to each other. Also, in the following explanation, the direction in which the central axis P of the stator 941 and rotor 942 extends is referred to as the axial direction, and the radial direction of the stator 941 and rotor 942 is simply referred to as the radial direction.
[0026] [Embodiment 1] Figure 1 is a diagram showing the schematic configuration of a cooling system 1 according to Embodiment 1 of the present invention. Referring to Figure 1, the cooling system 1 supplies a refrigerant to a rotational test device 90 that rotates a test specimen T. In Figure 1, the connection direction of the test specimen T is indicated by an arrow. The test specimen T may, for example, have a motor as a rotating body. The rotational test device 90 has a motor that rotates the test specimen T. The rotational test device 90 has a first refrigerant supply port 901, a second refrigerant supply port 902, a refrigerant discharge port 903, a bearing 91, and a motor coil 92. The cooling system 1 has a first refrigerant flow path 10, a second refrigerant flow path 20, a third refrigerant flow path 30, and a plurality of heat exchangers 401, 40, 60.
[0027] The first refrigerant passage 10, the second refrigerant passage 20, and the third refrigerant passage 30 are passages through which the refrigerant supplied to the rotational test device 90 flows. The refrigerant is, for example, a liquid refrigerant, and is a lubricating oil that also has the function of lubricating the bearing 91.
[0028] The first refrigerant flow path 10 is connected to the refrigerant outlet 903 of the rotational test device 90. The second refrigerant flow path 20 and the third refrigerant flow path 30, which will be described below, are connected to the branching point N1 located at the end of the first refrigerant flow path 10 in the direction of refrigerant flow.
[0029] The second refrigerant flow path 20 is a flow path that supplies a portion of the refrigerant flowing through the first refrigerant flow path 10 to the first refrigerant supply port 901 of the rotational test device 90.
[0030] The third refrigerant flow path 30 is a flow path that supplies the remaining portion of the refrigerant flowing through the first refrigerant flow path 10 to the second refrigerant supply port 902 of the rotational test device 90.
[0031] The refrigerant flowing from the second refrigerant passage 20 to the first refrigerant supply port 901 is supplied to the bearing 91 of the rotational test device 90. The refrigerant flowing from the third refrigerant passage 30 to the second refrigerant supply port 902 is supplied to the coil 92 of the rotational test device 90. In this way, the first refrigerant passage 10, the second refrigerant passage 20, and the third refrigerant passage 30 constitute a refrigerant circuit via the rotational test device 90.
[0032] The multiple heat exchangers 401, 40, and 60 perform heat exchange of the refrigerant supplied to the rotational test apparatus 90. The multiple heat exchangers 401, 40, and 60 include a first heat exchanger 401, one or more heat exchangers 40, and one or more second heat exchangers 60.
[0033] The first heat exchanger 401 and one or more heat exchangers 40 are arranged on the first refrigerant flow path 10 to perform heat exchange of the refrigerant flowing in the first refrigerant flow path 10. The first heat exchanger 401 has, for example, a heat exchanger that performs heat exchange between the refrigerant and industrial water. The industrial water is, for example, water supplied as non-potable water for purposes that do not come into direct contact with the human body. The industrial water is supplied, for example, by a water utility. The industrial water may be, for example, groundwater, surface water such as rivers or dams that has undergone sedimentation treatment at a water treatment plant and is supplied to consumers without undergoing water treatment for drinking water.
[0034] One or more heat exchangers 40 are located on the side of the refrigerant flow direction relative to the first heat exchanger 401. The heat exchanger 40 is, for example, a chiller that circulates LLC (Long Life Coolant). When the cooling system 1 has a plurality of heat exchangers 40, each of the heat exchangers 40 is arranged in series.
[0035] The second heat exchanger 60 is positioned on the third refrigerant flow path 30 to perform heat exchange of the refrigerant flowing through the third refrigerant flow path 30. The second heat exchanger 60 is, for example, a chiller that circulates LLC (Long Life Coolant). When the cooling system 1 has a plurality of second heat exchangers 60, each of the second heat exchangers 60 is arranged in series.
[0036] In the configuration described above, the first refrigerant flow path 10 is connected to the second refrigerant flow path 20 and the third refrigerant flow path 30 at the branching point N1. Therefore, a portion of the refrigerant that has undergone heat exchange by the first heat exchanger 401 located on the first refrigerant flow path 10 flows into the first refrigerant supply port 901 of the rotational test device 90 via the second refrigerant flow path 20, while the remainder flows into the third refrigerant flow path 30. Furthermore, the refrigerant that has flowed into the third refrigerant flow path 30 undergoes further heat exchange by the second heat exchanger 60 located on the third refrigerant flow path 30 and flows into the second refrigerant supply port 902 of the rotational test device 90.
[0037] For example, to lower the temperature of the refrigerant to a lower temperature, the size of the heat exchanger needs to be larger. With the above configuration, the temperature of the remaining portion of the refrigerant flowing into the second refrigerant supply port 902 can be lowered to a temperature lower than the temperature of a portion of the refrigerant flowing into the first refrigerant supply port 901. Therefore, the size of each of the multiple heat exchangers 401, 40, and 60 on the refrigerant circuit can be kept to a minimum compared to lowering the temperature of the entire refrigerant.
[0038] This makes it possible to lower the temperature of some of the refrigerants to a lower level while keeping the size of one or more heat exchange devices, such as the heat exchange device 40 and the second heat exchange device 60, down to a lower temperature.
[0039] Furthermore, according to the above configuration, in addition to the first heat exchanger 401, one or more heat exchangers 40 can perform heat exchange of the refrigerant flowing in the first refrigerant flow path 10. For example, the refrigerant delivered from the first heat exchanger 401 can be further cooled by one or more heat exchangers 40. Therefore, the refrigerant can be cooled to a desired temperature without increasing the size of the first heat exchanger 401. Also, industrial water has temperature variations. Even if there are variations in the temperature of the industrial water used for heat exchange in the first heat exchanger 401, these temperature variations can be suppressed by the refrigerant circulation method heat exchange in one or more heat exchangers 40. For example, if the temperature of the industrial water is higher than average, the heat exchanger 40 can further cool the refrigerant. On the other hand, if the temperature of the industrial water is lower than the temperature of the refrigerant to be supplied to the first refrigerant supply port 901, the heat exchanger 40 can also heat the refrigerant. This makes it possible to supply refrigerant with less temperature variation to the first refrigerant supply port 901 of the rotational test apparatus 90.
[0040] Furthermore, according to the above configuration, a cooling system can be realized to cool the lubricating oil flowing to the bearing 91 of the rotational testing device 90.
[0041] Furthermore, the coil 92 is a component that easily generates heat when the rotational test device 90 is driven. With the above configuration, the coil 92 can be efficiently cooled by supplying a refrigerant at a lower temperature than the refrigerant supplied to the first refrigerant supply port 901 to the second refrigerant supply port 902.
[0042] [Embodiment 2] Figure 2 is a diagram showing the schematic configuration of the cooling system 2 according to Embodiment 2 of the present invention. Figure 3 is a diagram showing the flow of refrigerant inside the rotational test device 90. In the cooling system 2 according to Embodiment 2 of the present invention, the rotational test device 90 is provided with a flow path for refrigerant to flow to the stator 941, a flow path for refrigerant to flow to the coil 92, and a flow path for refrigerant to flow to the bearing 91. In the following, the same reference numerals are used for parts that are the same as in Embodiment 1 and their descriptions are omitted, and only parts that differ from Embodiment 1 will be described.
[0043] (Cooling System) Referring to Figures 2 and 3, the cooling system 2 includes a first refrigerant flow path 10, a second refrigerant flow path 20, a third refrigerant flow path 30, and a plurality of heat exchange devices 401, 41, 42, 61. The plurality of heat exchange devices 401, 41, 42, 61 include a first heat exchange device 401, heat exchange devices 41, 42, and a second heat exchange device 61.
[0044] The first heat exchange device 401 and the heat exchange devices 41, 42 are disposed on the first refrigerant flow path 10 so as to perform heat exchange for the refrigerant flowing through the inside of the first refrigerant flow path 10. In the first refrigerant flow path 10, the first heat exchange device 401 and the heat exchange devices 41, 42 are arranged in the order of the first heat exchange device 401, the heat exchange device 41, and the heat exchange device 42 in the flowing direction of the refrigerant. The heat exchange devices 41 and 42 are, for example, chillers of a refrigerant circulation type that circulate LLC.
[0045] The second heat exchange device 61 is disposed on the third refrigerant flow path 30 so as to perform heat exchange for the refrigerant flowing through the inside of the third refrigerant flow path 30. The second heat exchange device 61 is, for example, a chiller of a refrigerant circulation type that circulates LLC.
[0046] (Rotation Test Apparatus) Referring to Figure 3, the rotation test apparatus 90 includes a stator 941, a coil 92, a shaft 93, a rotor 942, a casing 951, one cover 952, the other cover 953, a first refrigerant supply port 901, a second refrigerant supply port 902, a refrigerant discharge port 903, and a bearing 91.
[0047] The stator 941 extends in the axial direction about the central axis P. The stator 941 has a cylindrical shape. The coil 92 is wound around a slot formed in the stator 941.
[0048] The shaft 93 extends in the direction (axial direction) in which the central axis P of the rotation test apparatus 90 as a motor extends. The rotor 942 is supported by the bearing 91 so as to be rotatable about the central axis P together with the shaft 93 extending in the axial direction. The rotor 942 is located, for example, radially inward of the stator 941.
[0049] The casing 951 extends axially so as to cover the stator 941 at a position radially outward from the stator 941. The casing 951 is provided with a first refrigerant supply port 901B, a second refrigerant supply port 902, and a refrigerant discharge port 903B.
[0050] On the other hand, the cover 952 is positioned in one axial direction relative to the casing 951. On the other hand, the cover 952 covers one axial end of the casing 951.
[0051] On the other hand, cover 953 is located in the other axial direction relative to casing 951. On the other hand, cover 952 covers the other axial end of casing 951.
[0052] On one side, cover 952 and the other cover 953 are provided with a bearing 91, a first refrigerant supply port 901A, and a refrigerant discharge port 903A.
[0053] A second refrigerant flow path 20 is connected to the first refrigerant supply port 901A in the cover 952 and the other cover 953, and to the first refrigerant supply port 901B in the casing 951.
[0054] A third refrigerant flow path 30 is connected to the second refrigerant supply port 902 in the casing 951.
[0055] The refrigerant supplied to the first refrigerant supply port 901A is supplied to the bearing 91. The refrigerant supplied to the second refrigerant supply port 902 is injected onto the coil 92 from an injection port located inside the rotation test device 90. The refrigerant supplied to the bearing 91 and the refrigerant injected onto the coil 92 merge inside the rotation test device 90 and are discharged from the refrigerant discharge port 903A.
[0056] The refrigerant supplied to the first refrigerant supply port 901B passes between the outer circumferential surface of the stator 941 and the inner circumferential surface of the casing 951 and is discharged from the refrigerant discharge port 903B.
[0057] (First heat exchanger) The first heat exchanger 401 includes a storage tank 402, a refrigerant return port 403A, a refrigerant return port 403B, a suction pump 404, a discharge pump 405, a heat exchanger 406, and a refrigerant inlet 407.
[0058] The storage tank 402 is a tank for storing refrigerant. The refrigerant return port 403A is connected to the refrigerant outlet 903A. The refrigerant return port 403B is connected to the refrigerant outlet 903B. The refrigerant discharged from the refrigerant outlet 903B flows through the refrigerant return port 403B into the storage tank 402.
[0059] The suction pump 404 sucks in the refrigerant discharged from the refrigerant outlet 903A and sends it to the storage tank 402.
[0060] The discharge pump 405 sends the refrigerant stored in the storage tank 402 to the refrigerant inlet 407.
[0061] The heat exchanger 406 is located between the discharge pump 405 and the refrigerant inlet 407. The heat exchanger 406 performs heat exchange between the refrigerant delivered by the discharge pump 405 and industrial water.
[0062] The refrigerant inlet 407 is connected to the first refrigerant flow path 10. The refrigerant discharged from the storage tank 402 by the discharge pump 405 is supplied to the first refrigerant flow path 10 through the refrigerant inlet 407.
[0063] (Example of Cooling System Operation) Figure 4 is a diagram showing the schematic configuration of a conventional cooling system 500. Referring to Figures 2 and 3, as well as Figure 4, the operation of the conventional cooling system 500 will be explained, and an example of the operation of the cooling system 2 will be described.
[0064] First, referring to Figure 4, the conventional cooling system 500 includes a first refrigerant flow path 510, a second refrigerant flow path 520, a third refrigerant flow path 530, and a heat exchanger 501.
[0065] In the cooling system 500, the first refrigerant flow path 510 is connected to the refrigerant outlet 903 of the rotational test device 90. The first refrigerant flow path 510 branches into a second refrigerant flow path 520 and a third refrigerant flow path 530 at a branching point N500 located at the end in the direction of refrigerant flow. The second refrigerant flow path 520 is connected to the first refrigerant supply port 901. The third refrigerant flow path 530 is connected to the second refrigerant supply port 902.
[0066] In the cooling system 500, the refrigerant is discharged from the refrigerant outlet 903 at a flow rate of Fout (L / min). In the cooling system 500, the temperature of the refrigerant rises due to the heat generated in the rotational test device 90. A maximum of Tout (°C) of refrigerant is discharged from the rotational test device 90.
[0067] A heat exchanger 501 is located in the first refrigerant flow path 510. The heat exchanger 501 performs heat exchange between the refrigerant and industrial water. Through heat exchange in the heat exchanger 501, the refrigerant is cooled to Tx (°C), which is lower than Tout (°C). The refrigerant that has passed through the heat exchanger 501 flows toward the branching point N500 between the second refrigerant flow path 520 and the third refrigerant flow path 530 at a flow velocity of Fx (L / min). Here, for example, Fout is equal to Fx.
[0068] At branching point N500, a portion of the refrigerant flows into the second refrigerant flow path 520 at a flow velocity of Fx1 (L / min), while the remaining portion of the refrigerant flows into the third refrigerant flow path 530 at a flow velocity of Fx2 (L / min). Here, Fx1 + Fx2 = Fx. The temperature of the refrigerant flowing through the second refrigerant flow path 520 and the third refrigerant flow path 530 is Tx (°C), the same as in the first refrigerant flow path 510.
[0069] In some cases, a temperature lower than Tx (°C) may be required for the refrigerant supplied to the second refrigerant supply port 902. To cool the refrigerant to the aforementioned lower temperature, a larger heat exchanger with higher cooling performance is required.
[0070] In contrast, the cooling system 2 includes a first refrigerant flow path 10, a second refrigerant flow path 20, a third refrigerant flow path 30, and a plurality of heat exchangers 401, 41, 42, and 61.
[0071] In cooling system 2, refrigerant is discharged from refrigerant outlets 903A and 903B at a flow rate of Fout (L / min). Fout (L / min) corresponds to the total flow rate of refrigerant flowing through refrigerant outlets 903A and 903B. In Figure 3, refrigerant outlets 903A and 903B are distinguished, but in Figure 2, for the sake of simplicity, refrigerant outlets 903A and 903B are not distinguished and are simply represented by the symbol 903. A maximum of Tout (°C) of refrigerant is discharged from refrigerant outlet 903.
[0072] The refrigerant is cooled to T11 (°C), which is lower than Tout (°C), by heat exchange in the heat exchanger 406 of the first heat exchanger 401. The refrigerant that has passed through the heat exchanger 406 of the first heat exchanger 401 flows into the heat exchanger 41 at a flow rate of F1 (L / min). Here, for example, Fout is equal to F1.
[0073] In heat exchanger 41, LLC with a temperature of TC1 (°C) lower than T11 (°C) circulates at a flow rate of C1 (L / min). In heat exchanger 42, LLC with a temperature of TC2 (°C) lower than TC1 (°C) circulates at a flow rate of C2 (L / min). C1 and C2 are, for example, the same.
[0074] The refrigerant that has passed through the heat exchanger 41 is cooled to T12 (°C), which is between T11 (°C) and TC1 (°C), and flows into the heat exchanger 42 at a flow rate of F1 (L / min). The refrigerant that has passed through the heat exchanger 42 is cooled to T13 (°C), which is between T12 (°C) and TC2 (°C), and reaches the branching point N1 at a flow rate of F1 (L / min).
[0075] At branching point N1, a portion of the refrigerant flows into the second refrigerant flow path 20 at a flow velocity of F2 (L / min), while the remaining portion of the refrigerant flows into the third refrigerant flow path 30 at a flow velocity of F3 (L / min). Here, F2 + F3 = F1. Alternatively, F2 > F3 may also apply. The cross-sectional area of the first refrigerant flow path 10 may be the sum of the cross-sectional areas of the second refrigerant flow path 20 and the third refrigerant flow path 30. The refrigerant flowing through the second refrigerant flow path 20 is supplied to the first refrigerant supply ports 901A and 901B. Specifically, the second refrigerant flow path 20 branches and is connected to the first refrigerant supply ports 901A and 901B, respectively.
[0076] Note that F2 (L / min) corresponds to the total flow rate of refrigerant flowing through the first refrigerant supply ports 901A and 901B. Also, in Figure 3, the first refrigerant supply ports 901A and 901B were distinguished, but in Figure 2, for the sake of simplifying the drawing, the first refrigerant supply ports 901A and 901B are not distinguished and are simply represented by the symbol 901. Refrigerant is supplied to the first refrigerant supply port 901 at a flow rate of F2 (L / min) and T13 (°C).
[0077] Furthermore, at branching point N1, the remaining refrigerant flows into the second heat exchanger 61 in the third refrigerant flow path 30 at T13 (°C).
[0078] LLC with a temperature of TC3 (°C), lower than TC2 (°C), circulates through the second heat exchanger 61 at a flow rate of C3 (L / min). C3 is, for example, the same as C1 or C2. The refrigerant that has passed through the second heat exchanger 61 is cooled to T14 (°C), which is between T13 (°C) and TC3 (°C), and flows into the second refrigerant supply port 902 at a flow rate of F3 (L / min).
[0079] In a chiller's refrigeration unit, the amount of heat that can be cooled decreases as the load outlet temperature, which is the target temperature for cooling, decreases. In cooling system 2, the temperature of the refrigerant can be lowered in stages by multiple heat exchangers 401, 41, 42, and 61. With the above configuration, the refrigerant can be cooled to a lower temperature while suppressing the heat load during cooling in each of the multiple heat exchangers 401, 41, 42, and 61. Note that the heat load of heat exchanger 41 may be smaller than the heat load of heat exchanger 42, and the heat load of heat exchanger 42 may be smaller than the heat load of the second heat exchanger 61.
[0080] According to the above configuration, a refrigerant at a temperature that meets the requirements can be supplied to the coil 92, which requires a lower temperature refrigerant.
[0081] Furthermore, changes in the oil temperature of the refrigerant affect the kinematic viscosity of the oil. The lower the oil temperature, the lower the kinematic viscosity. Therefore, the lower the oil temperature, the lower the flow rate or discharge volume of the oil flowing through the rotational test apparatus 90 may be. Depending on the piping structure within the rotational test apparatus 90, overcooling the oil may reduce the flow rate or discharge volume, thereby reducing the cooling capacity. Therefore, depending on the piping structure within the rotational test apparatus 90, for example, supplying a refrigerant at a temperature higher than T14 (°C), such as T13 (°C), may improve the cooling effect compared to supplying a refrigerant cooled to T14 (°C). For example, supplying a refrigerant at T13 (°C) allows for appropriate flow rate or discharge volume of the refrigerant flowing through the rotational test apparatus 90 and appropriate viscosity of the lubricating oil in the bearing 91.
[0082] Therefore, according to the above structure, a refrigerant at a suitable temperature can be supplied to each component in the rotational testing apparatus 90.
[0083] Furthermore, with the above configuration, the amount of refrigerant supplied to the rotational test device 90 can be adjusted by storing the refrigerant in the storage tank 402. This allows a desired amount of refrigerant to be smoothly supplied to the rotational test device 90.
[0084] (Other Embodiments) Although embodiments of the present invention have been described above, the embodiments described above are merely examples for carrying out the present invention. Therefore, the invention is not limited to the embodiments described above, and it is possible to carry out the invention by appropriately modifying the embodiments described above without departing from the spirit of the invention.
[0085] In each of the above embodiments, a cooling oil is used as the refrigerant. However, the refrigerant may also be a gas or water.
[0086] In each of the above embodiments, the first heat exchanger 401 and one or more heat exchangers 40, 41, 42 are arranged on the first refrigerant flow path 10. In addition, one or more second heat exchangers 60, 61 are arranged on the third refrigerant flow path 30. However, one or more heat exchangers do not have to be arranged on the first refrigerant flow path. Alternatively, one or more heat exchangers may be further arranged on the second refrigerant flow path.
[0087] In each of the above embodiments, the refrigerant is cooled during heat exchange between the first heat exchanger 401 and one or more heat exchangers 40, 41, 42 and one or more second heat exchangers 60, 61. However, the first heat exchanger and one or more heat exchangers and one or more second heat exchangers may heat the refrigerant if the temperature of the supplied refrigerant is lower than that of industrial water or LLC.
[0088] Although not specifically described in the above embodiments, the piping structure within the rotational test apparatus may be provided with a valve capable of adjusting the flow rate of the refrigerant.
[0089] In the second embodiment described above, one cover 952 and the other cover 953 are provided with a first refrigerant supply port 901A. However, the one cover and the other cover may also be provided with a second refrigerant supply port. The refrigerant may be injected into the coil through the second refrigerant supply port provided in the one cover and the other cover.
[0090] In the above embodiment 2, the coil 92 is wound around a slot formed in the stator 941. However, the coil may also be wound around the rotor.
[0091] In the above embodiment 2, the suction pump 404 sucks in the refrigerant discharged from the refrigerant outlet 903A. However, the suction pump may also suck in air supplied to the rotation test apparatus, not just refrigerant.
[0092] In the above embodiment 2, for example, C1, C2, and C3 are the same. However, C1, C2, and C3 may be different from each other. Also, C1, C2, and C3 may be smaller than F1.
[0093] This invention can be used in a cooling system that supplies a refrigerant to a rotating test apparatus that rotates a test specimen.
[0094] 1, 2 Cooling System 10 First Refrigerant Flow 20 Second Refrigerant Flow 30 Third Refrigerant Flow 401, 40, 41, 42, 60, 61 Multiple Heat Exchangers 401 First Heat Exchanger 402 Storage Tank 403A, 403B Refrigerant Return Port 404 Suction Pump 405 Discharge Pump 406 Heat Exchanger 407 Refrigerant Inlet 40, 41, 42 Heat Exchanger 60, 61 Second Heat Exchanger 90 Rotation Testing Device 901, 901A, 901B First Refrigerant Supply Port 902 Second Refrigerant Supply Port 903, 903A, 903B Refrigerant Discharge Port 91 Bearing 92 Coil 93 Shaft 941 Stator 942 Rotor 951 Casing 952 One Cover 953 Other Cover P Center Axis T Specimen
Claims
1. A cooling system for supplying a refrigerant to a rotating test apparatus for rotating a test specimen, comprising: a first refrigerant flow path connected to a refrigerant outlet of the rotating test apparatus; a second refrigerant flow path that supplies a portion of the refrigerant flowing through the first refrigerant flow path to a first refrigerant supply port of the rotating test apparatus; a third refrigerant flow path that supplies the remaining portion of the refrigerant flowing through the first refrigerant flow path to a second refrigerant supply port of the rotating test apparatus; and a plurality of heat exchange devices that perform heat exchange of the refrigerant supplied to the rotating test apparatus, wherein the plurality of heat exchange devices include: a first heat exchange device arranged on the first refrigerant flow path to perform heat exchange of the refrigerant flowing through the first refrigerant flow path; and a second heat exchange device arranged on the third refrigerant flow path to perform heat exchange of the refrigerant flowing through the third refrigerant flow path.
2. A cooling system according to claim 1, wherein the first heat exchange device has a heat exchanger that performs heat exchange between the refrigerant and industrial water, and the plurality of heat exchange devices further include one or more heat exchange devices arranged on the first refrigerant flow path to perform heat exchange of the refrigerant flowing in the first refrigerant flow path, and the one or more heat exchange devices are located on the side of the direction of travel of the refrigerant with respect to the first heat exchange device.
3. The cooling system according to claim 2, wherein the first heat exchanger further comprises: a suction pump for drawing the refrigerant from the test specimen; a storage tank for storing the refrigerant; and a discharge pump for discharging the refrigerant from the storage tank.
4. A cooling system according to any one of claims 1 to 3, wherein the refrigerant is a lubricating oil, and the cooling system supplies the refrigerant flowing into the first refrigerant supply port to a bearing of the rotational test device.
5. A cooling system according to any one of claims 1 to 3, wherein the rotational test device includes a motor having a coil, and the cooling system supplies the refrigerant flowing into the second refrigerant supply port to the coil.