JP2017025810A - Rotary machine, and manufacturing method of heat insulation structure for rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary machine which reduces a heat intrusion amount by an intermediate heat transfer part and is also effective to reduce the heat intrusion amount propagated via a casing.SOLUTION: A cryogenic rotary machine 10 comprises: an impeller 12 disposed within a heat insulation container 8; a drive motor 14 which is disposed outside the heat insulation container 8 and rotates the impeller 12 via a rotary shaft 13; a heat insulation part 23 which surrounds a part of the rotary shaft 13 within the heat insulation container 8; a casing 15 which is fixed to the heat insulation container 8 and encloses the heat insulation part 23; and a middle heat transfer part 27 which vertically partitions the heat insulation part 23, is abutted to the casing 15 and reduces the heat intrusion amount that is propagated via the rotary shaft 13 while being maintained at a constant temperature Ts. In the state where influences of the middle heat transfer part 27 are excluded, in the cryogenic rotary machine 10, the casing 15 has a temperature gradient G within the heat insulation container 8, and the middle heat transfer part 27 is provided at a position where the temperature gradient G of the casing 15 corresponds to the constant temperature Ts.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a rotating machine for transferring a fluid passing through a pipe in a heat insulating container, for example, a fluid such as cryogenic helium, and a method for manufacturing a heat insulating structure of the rotating machine.

  Conventionally, for example, helium is used to cool a superconducting magnet at an extremely low temperature, and a low-temperature rotating machine for a circulation device that circulates this helium is known (see Patent Document 1). In this type of low-temperature rotating machine, an impeller is disposed in a heat insulating container such as a cold storage container, and a driving motor is disposed outside the heat insulating container. The drive motor rotates the impeller through a rotating shaft, and circulates and transfers a fluid such as helium that passes through the piping in the heat insulating container.

  The impeller is accommodated in a casing fixed to the heat insulating container, and the casing surrounds the heat insulating material arranged around the rotation shaft. The heat insulating material is formed with a groove portion to which a circulating cooling gas is supplied. The groove portion is maintained at a low temperature by the circulation of the cooling gas. As a result, the groove portion functions as an intermediate heat transfer portion, and reduces the intrusion heat transmitted through the heat insulating material and the casing.

JP-A-6-193598

  In the past, in order to reduce the intrusion heat transmitted through the heat insulating material and the casing, it has been considered desirable to arrange the intermediate heat transfer section as high as possible. However, as the intermediate heat transfer section is arranged on the high temperature side, the temperature difference between the intermediate heat transfer section maintained at a constant temperature and the casing becomes larger, and a portion of the casing in contact with the intermediate heat transfer section is locally Thermal shrinkage increases, stress concentration occurs, and an excessive load is applied to the casing. As a result, it is difficult to reduce the thickness of the casing, and there is a possibility that the amount of heat intrusion transmitted through the casing is not sufficiently reduced.

  The present invention provides a rotating machine that reduces the amount of heat intrusion by the intermediate heat transfer section and is also effective in reducing the amount of heat intrusion transmitted through the casing, and a method for manufacturing the heat insulating structure of the rotating machine. Objective.

  One aspect of the present invention is a rotating machine that transfers a fluid that passes through a pipe in a heat insulating container, the impeller that is disposed in the heat insulating container and transfers the fluid by rotation, and is disposed outside the heat insulating container and rotates. A drive unit that rotates the impeller via the shaft, a heat insulating unit that surrounds at least a part of the rotating shaft in the heat insulating container, a casing that is fixed to the heat insulating container and surrounds the heat insulating unit, and a drive unit that drives the heat insulating unit An intermediate heat transfer section that is divided into a side and an impeller side, abuts against the casing, and is maintained at a constant temperature to reduce the amount of heat intrusion from the drive section side to the impeller side. The casing has a temperature distribution in which the temperature decreases from the drive unit side to the impeller side in the heat insulating container, and the intermediate heat transfer unit is provided at a position where the temperature distribution of the casing corresponds to the constant temperature. Is There.

  In this rotating machine, the intermediate heat transfer section is provided such that the temperature distribution of the casing and the constant temperature of the intermediate heat transfer section are in a corresponding position. That is, while effectively reducing the amount of heat penetration by the intermediate heat transfer section, the temperature difference generated between the intermediate heat transfer section and the casing can be reduced to reduce the load on the casing. As a result, it is easy to reduce the thickness of the casing, and it becomes easy to sufficiently reduce the amount of heat intrusion transmitted through the casing. In addition, the position where the temperature distribution of the casing and the constant temperature of the intermediate heat transfer section correspond to the position where the temperature distribution of the casing and the constant temperature of the intermediate heat transfer section match, and to reduce the amount of heat penetration to a desired level This means that the thinned casing allows an error in a range that can withstand heat shrinkage due to a temperature difference in terms of strength.

  In some embodiments, a cylindrical portion surrounding the heat insulating portion, and a fixing portion provided in the cylindrical portion and fixed to the heat insulating container, the cylindrical portion being an outer end portion connected to the fixing portion And the inner end portion on the impeller side, and the temperature distribution of the casing can be a temperature gradient in which the temperature decreases from the outer end portion to the inner end portion of the cylindrical portion. The temperature distribution of the casing can be approximated by a temperature gradient. Therefore, by defining the temperature distribution of the casing as a temperature gradient, detailed indexing of the temperature distribution becomes unnecessary, and appropriate arrangement of the intermediate heat transfer section is facilitated.

  Further, the temperature difference between the temperature at the outer end of the cylindrical portion and the above constant temperature is ΔTa, the temperature difference between the temperature at the inner end of the cylindrical portion and the above constant temperature is ΔTb, When the distance to the heat transfer part is Xa and the distance from the inner end part to the intermediate heat transfer part is Xb, the position where the temperature gradient of the casing corresponds to the constant temperature is ΔTa / ΔTb = Xa / Xb It can be a position that satisfies the condition. If ΔTa and ΔTb are determined, the position of the intermediate heat transfer portion is determined from the distance between the outer end portion and the inner end portion of the cylindrical portion, so that the arrangement of the intermediate heat transfer portion at an appropriate position is facilitated.

  In some embodiments, the intermediate heat transfer section may be arranged closer to the impeller side than the center of the cylindrical portion in the rotation axis direction. In this configuration, even if the constant temperature of the intermediate heat transfer section is lower than the intermediate temperature of the temperature distribution, the intermediate heat transfer section can be appropriately arranged.

  In some embodiments, a cooling line connected to the intermediate heat transfer section so as to be capable of exchanging heat and circulating the refrigerant to maintain the intermediate heat transfer section at a constant temperature may be further provided. By providing the cooling line, the intermediate heat transfer section can be more reliably maintained at a constant temperature.

  In some embodiments, the intermediate heat transfer section includes a plate-shaped partition portion having a through hole through which the rotation shaft passes, and a cylindrical heat receiving portion provided along the through hole and facing the rotation shaft. The heat receiving part may be provided so as to protrude toward the drive part side of the partition part. By providing the heat receiving part protruding to the drive part side of the partitioning part, the heat receiving part is arranged on the high temperature side compared to the partitioning part, and the amount of heat intrusion transmitted through the rotating shaft is higher than the rotating shaft side. It is advantageous to be able to reduce from.

  Another embodiment of the present invention is a method for manufacturing a heat insulating structure of a rotating machine that transfers a fluid that passes through a pipe in a heat insulating container. The rotating machine is disposed in the heat insulating container and transfers the fluid by rotation. And an impeller disposed outside the heat insulating container and rotating the impeller via the rotating shaft, a heat insulating portion surrounding at least a part of the rotating shaft in the heat insulating container, and being fixed to the heat insulating container, A casing that surrounds the heat insulating part, and an intermediate transmission that divides the heat insulating part into a drive part side and an impeller side, abuts against the casing, and is maintained at a constant temperature to reduce the amount of heat intrusion from the drive part side to the impeller side. A temperature distribution of the casing that is reduced in temperature from the drive unit side to the impeller side in the heat insulating container, assuming that the influence of the intermediate heat transfer unit is excluded, and is derived. Warm Distribution and a constant temperature is provided an intermediate heat transfer unit in the corresponding position. According to this manufacturing method, it is possible to manufacture a heat insulating structure for a rotating machine that is effective in reducing the amount of heat intrusion transmitted through the casing while appropriately disposing the intermediate heat transfer section.

  Further, one embodiment of the present invention includes a normal temperature side casing and a heat insulating portion that surrounds a part of the impeller's rotating shaft, and the heat insulating portion reduces the amount of heat transmitted from the normal temperature side casing side through the rotating shaft. A low-temperature side casing including an intermediate heat transfer portion, and a rotary machine for transferring a fluid, wherein the temperature of the contact point with the intermediate heat transfer portion of the low-temperature side casing and the intermediate heat transfer portion Corresponds to temperature.

  In this rotating machine, the temperature of the contact portion of the low-temperature casing with the intermediate heat transfer portion corresponds to the temperature of the intermediate heat transfer portion. That is, while effectively reducing the amount of heat penetration by the intermediate heat transfer section, the temperature difference generated between the intermediate heat transfer section and the low temperature casing can be reduced to reduce the load on the low temperature casing. As a result, the low-temperature casing can be easily thinned, and the amount of heat penetration transmitted through the low-temperature casing can be easily reduced sufficiently. The correspondence between the temperature of the contact portion of the low temperature casing with the intermediate heat transfer portion and the temperature of the intermediate heat transfer portion is the temperature of the contact portion of the low temperature casing with the intermediate heat transfer portion and the temperature of the intermediate heat transfer portion. , And the low-temperature casing thinned to reduce the amount of heat penetration to the desired level allows for an error in a range that can withstand heat shrinkage due to a temperature difference in strength. .

  According to some aspects of the present invention, the heat intrusion amount is reduced by the intermediate heat transfer section, and the heat intrusion amount transmitted through the casing is also effective.

It is a schematic explanatory drawing which shows the whole cooling system. It is a side view which shows the cryogenic rotary machine which concerns on this embodiment partially fractured | ruptured. It is sectional drawing which expands and shows the low temperature side casing part and intermediate | middle heat-transfer part of the cryogenic rotary machine which concern on this embodiment. It is sectional drawing along the IV-IV line of FIG. It is a graph which shows the temperature gradient in the cylindrical part of a low temperature side casing part. It is sectional drawing which shows typically the relationship between arrangement | positioning of an intermediate | middle heat-transfer part, and the thermal contraction of a cylindrical part, Fig.6 (a) does not arrange | position the cyclic | annular protrusion part and intermediate | middle heat-transfer part of a cylindrical part. FIG. 6B is a diagram illustrating a state in which the annular projecting portion of the cylindrical portion and the intermediate heat transfer portion are arranged on the higher temperature side than the corresponding position of the temperature gradient. (c) is a figure which shows the state which has arrange | positioned the cyclic | annular protrusion part of a cylindrical part, and the intermediate | middle heat-transfer part in the position corresponding to a temperature gradient.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted.

  First, the cooling system 1 provided with the cryogenic rotating machine 10 will be described with reference to FIG. The cooling system 1 is a system for cooling the superconducting magnet 2 with a circulating fluid. In this cooling system 1, helium is used as the circulating fluid, but depending on the object to be cooled, a fluid such as nitrogen, hydrogen, neon, or the like may be used. In the present embodiment, the cryogenic rotating machine 10 will be described as an example of a rotating machine.

  The cooling system 1 includes a circulation line 3 through which helium (hereinafter referred to as “main refrigerant”) Mf circulates, a cryogenic rotating machine 10 such as a circulator pump that pumps the main refrigerant Mf passing through the circulation line 3, and a circulation line 3. The cooling device 4 that cools the main refrigerant Mf that passes through to about 4K (very low temperature), the first heat exchanger 5 that connects the superconducting magnet 2 and the circulation line 3 so that heat exchange is possible, and the superconductivity of the circulation line 3 The second heat exchanger 6 is disposed downstream of the magnet 2 and connects the cooling device 4 and the circulation line 3 so that heat exchange is possible.

  As shown in FIGS. 1 and 2, the circulation line 3 includes a pipe 3 a through which the main refrigerant Mf passes, and is arranged in the heat insulating container 8 in order to avoid the influence of outside air temperature (normal temperature). . The inside of the heat insulating container 8 is kept in vacuum in order to prevent the temperature of the main refrigerant Mf from rising due to convection. A main portion 11 of the cryogenic rotating machine 10 is installed on the ceiling portion 8 a of the heat insulating container 8. The main part 11 of the cryogenic rotating machine 10 includes an impeller 12 that transfers the main refrigerant Mf by rotation, and a drive motor 14 that rotates the impeller 12 via a rotating shaft 13. In the present embodiment, the drive motor 14 will be described as an example of a drive unit.

  The cryogenic rotating machine 10 includes a casing 15 that houses the main part 11. The casing 15 includes a normal temperature side casing portion 16 that accommodates the drive motor 14 and a low temperature side casing portion 17 that accommodates the impeller 12. The normal temperature side casing portion 16 is disposed outside the heat insulating container 8, and has a low temperature. The side casing portion 17 is mainly disposed inside (inside) the heat insulating container 8.

  The low temperature side casing portion 17 accommodates the impeller 12, an impeller chamber 18 connected to the pipe 3 a of the circulation line 3, and a thin cylindrical cylindrical portion 19 erected from the impeller chamber 18 along the rotation shaft 13. And a fixed flange portion 20 provided so as to protrude from the upper end side of the cylindrical portion 19. The low temperature side casing portion 17 is passed through a circular hole formed in the partition wall 81 of the heat insulating container 8, and the fixing flange portion 20 is fixed to the partition wall 81 by welding.

  The room temperature side casing portion 16 is erected so as to surround the rotary shaft 13, and has a cylindrical body portion 16a that houses the drive motor 14, a lid portion 16b that closes an upper opening of the body portion 16a, and a lower end of the body portion 16a. And a flange portion 16c provided on the surface. The flange portion 16c overlaps the upper surface of the fixed flange portion 20 of the low temperature side casing portion 17, and is bolted to the fixed flange portion 20 while ensuring a sealed state with a seal member interposed therebetween. The main part 11 can be pulled out from the low temperature side casing part 17 by loosening the bolt of the flange part 16 c and detaching the normal temperature side casing part 16 from the low temperature side casing part 17. Specifically, the impeller 12, a part of a heat insulating part 23 to be described later, and the intermediate heat transfer part 27 can be pulled out from the low temperature side casing part 17 together with the rotating shaft 13 supported by the room temperature side casing part 16. Furthermore, the main part 11 can be easily maintained by opening the cover part 16b of the room temperature side casing part 16.

  Inside the normal temperature side casing portion 16, radial bearing portions 21 are arranged at two places above and below so as to sandwich the drive motor 14. Further, between the drive motor 14 and the lower radial bearing portion 21, A thrust bearing portion 22 that supports the rotary shaft 13 while receiving a load in the direction of the rotary shaft 13 is disposed.

  A heat insulating material is accommodated inside the low temperature side casing portion 17 to form a heat insulating portion 23. The heat insulating portion 23 is formed with a circular through hole 23 a through which the rotary shaft 13 passes. As a result, the heat insulating portion 23 surrounds a part of the rotary shaft 13. In the present embodiment, the heat insulating portion 23 is formed by accommodating a heat insulating material inside the low temperature side casing portion 17. However, a vacuum heat insulating chamber is formed inside the low temperature side casing portion 17, and further inside the heat insulating chamber. It is also possible to arrange a convection prevention material to form a heat insulating part.

  The heat insulation part 23 is divided into upper and lower two stages, and an intermediate heat transfer part 27 maintained at a constant temperature of about −190 ° C. is disposed between the upper heat insulation part 24 and the lower heat insulation part 25. The intermediate heat transfer section 27 is also called a thermal anchor, has a thermal conductivity equal to or higher than that of the rotary shaft 13, and is formed of, for example, a copper plate. The intermediate heat transfer section 27 is provided to reduce the amount of intrusion heat transmitted from the high temperature side to the low temperature side via the rotary shaft 13, and is also effective in reducing the amount of intrusion heat slightly transmitted through the heat insulating section 23. is there. The lower heat insulating portion 25 is further divided into an inner portion 25a and an outer portion 25b, and only the inner portion 25a is pulled out together with the rotating shaft 13 and the intermediate heat transfer portion 27 during maintenance.

  The intermediate heat transfer portion 27 contacts an annular protrusion 30 provided on the inner surface side of the tubular portion 19. The annular protrusion 30 is maintained at a constant temperature by helium (hereinafter referred to as “sub-refrigerant”) Sf that circulates while being maintained at about −190 ° C. The intermediate heat transfer section 27 is maintained at a constant temperature of about −190 ° C. by exchanging heat with the annular protrusion 30 for the amount of heat transferred from the rotary shaft 13. In the present embodiment, an example in which helium is used as the auxiliary refrigerant Sf is illustrated, but nitrogen or the like may be used as necessary.

  The cryogenic rotating machine 10 includes a cooling line 31 for circulating the sub refrigerant Sf (see FIG. 1). The flow path 30a of the sub-refrigerant Sf formed in the annular projecting portion 30 has an inlet and an outlet in one pass, and is formed so as to make one round around the intermediate heat transfer portion 27. The cooling line 31 is a line for circulating the sub refrigerant Sf, and includes a pipe 31 a connected to each of the inlet and the outlet of the sub refrigerant Sf formed in the annular protrusion 30, a circulator pump (not shown), and the like. ing. The cooling line 31 is arranged to be able to exchange heat with the cooling device 110 via the third heat exchanger 7, and the sub-refrigerant Sf after heat exchange is maintained at −190 ° C. The sub refrigerant Sf supplied to and discharged from the annular protrusion 30 reaches the third heat exchanger 7 and is cooled again.

[Structure of intermediate heat transfer section]
As shown in FIG. 3 and FIG. 4, the intermediate heat transfer section 27 is a plate-shaped and annular partition section 27 a that partitions the upper heat insulation section 24 and the lower heat insulation section 25, and the inner periphery of the partition section 27 a. And a cylindrical portion 27b formed along the through hole 23a of the heat insulating portion 23 on the side. The inner surface of the cylindrical portion 27 b is opposed to the rotation shaft 13 and is provided with a slight gap that does not hinder rotation while being as close as possible to the rotation shaft 13. The cylindrical portion 27 b maintained at a constant temperature of about −190 ° C. has a function of exchanging heat with the rotating shaft 13 and reducing the amount of intrusion heat transmitted through the rotating shaft 13. The rotary shaft 13 is provided with a vacuum cavity 13a for reducing the amount of intrusion heat.

  The cylindrical portion 27b protrudes in both directions of the rotating shaft 13 with the partition portion 27a interposed therebetween, and particularly includes a heat receiving portion 27c protruding more toward the drive motor 14 side. As a result, the amount of heat intrusion transmitted through the rotating shaft 13 can be advantageously reduced from the higher temperature side than the position corresponding to the partition portion 27a of the rotating shaft 13.

  The partition portion 27a includes an inner main plate portion 27d connected to the cylindrical portion 27b, and an outer edge portion 27e which is thinner than the main plate portion 27d and has a step formed outside the main plate portion 27d. The outer edge portion 27 e contacts the cylindrical portion 19 of the low temperature side casing portion 17. On the inner surface side of the tubular portion 19, an annular projecting portion 30 that surrounds the intermediate heat transfer portion 27 and abuts on the outer edge portion 27 e is formed. In the annular projecting portion 30, a flow path 30 a of the one-pass (single flow path) sub refrigerant Sf that flows along the circumferential direction of the intermediate heat transfer section 27 is formed. The auxiliary refrigerant Sf circulates while being maintained at an extremely low temperature of about −190 ° C.

  The intermediate heat transfer part 27 is maintained at about −190 ° C. by heat exchange between the outer edge part 27 e and the annular protrusion part 30. Further, the outer edge portion 27e forms a step with respect to the main plate portion 27d, and is in contact with the annular protrusion 30 including the step. Therefore, the contact area with the annular projecting portion 30 becomes larger than when flat without a step, and heat exchange with the annular projecting portion 30 can be performed efficiently.

[Arrangement of intermediate heat transfer section and annular protrusion]
As shown in FIGS. 3 and 5, the low temperature side casing portion 17 has the highest temperature at the upper part on the drive motor 14 side (external side) fixed to the heat insulating container 8, and the impeller 12 side (internal side) is on the upper side. The lowest. Specifically, the low temperature side casing portion 17 has a temperature distribution such that the temperature is highest in the fixed flange portion 20 and lowest in the impeller chamber 18. Here, it is necessary to reduce the amount of intrusion heat from the fixed flange portion 20 to the impeller chamber 18 as much as possible. In order to reduce the amount of intrusion heat between the fixed flange portion 20 and the impeller chamber 18 as small as possible, A thin cylindrical portion 19 is disposed. The fixed flange portion 20 is an example of a fixed portion that is fixed to the heat insulating container 8.

  Moreover, the heat insulation part 23 is accommodated inside the cylindrical part 19, and also the reduction | decrease of the penetration | invasion heat amount transmitted through the rotating shaft 13 by the intermediate heat transfer part 27 is aimed at. The intermediate heat transfer section 27 is maintained at a constant temperature Ts of about −190 ° C., and the constant temperature maintenance of the intermediate heat transfer section 27 is performed with the sub-refrigerant Sf circulating in the annular protrusion 30 formed in the cylindrical section 19. Realized by heat exchange.

  Here, in the cryogenic rotating machine 10 according to the present embodiment, the test mode 100 (see FIG. 6A) in which the intermediate heat transfer portion 27, the annular protrusion 30 of the cylindrical portion 19, and the cooling line 31 do not exist. Assuming temperature distribution simulation. Then, the temperature distribution in the cylindrical portion 19 is highest at the upper end portion (outer end portion) 19a connected to the fixed flange portion 20 (about 0 ° C.) (see FIG. 5), and the lower end on the impeller 12 side. It can be approximated by a temperature gradient G having the lowest temperature (about −260 ° C.) at the portion (inner end portion) 19b. Moreover, since the cylindrical part 19 is reduced in diameter by the thermal contraction by temperature, although the difference is about 2 mm at the maximum, the diameter of the upper end part 19a is the largest and the diameter of the lower end part 19b is the smallest.

  Next, with respect to the cylindrical part 19 having the predetermined temperature gradient G in the test mode 100, the intermediate heat transfer part 27, the annular projecting part 30 of the cylindrical part 19, and the cooling line 31 are provided on the assumption. Here, when the temperature difference between the intermediate heat transfer portion 27 and the constant temperature Ts (for example, −190 ° C.) of the annular protrusion 30 and the tubular portion 19 becomes large (see FIG. 6B), the intermediate heat transfer portion. 27 and a portion Px of the cylindrical portion 19 where the annular protrusion 30 is disposed, the thermal shrinkage locally increases, stress concentration occurs, and an excessive load is applied to the cylindrical portion 19. Specifically, when the intermediate heat transfer portion 27 and the annular protrusion 30 having a temperature gradient G of −40 ° C. to −50 ° C. are arranged at a height of −40 ° C. to −50 ° C., the temperature exceeding 100 ° C. A difference arises, extreme thermal shrinkage occurs locally, and an excessive load is applied to the tubular portion 19. As a result, it is necessary to make the cylindrical portion 19 thick so that it can withstand this excessive load, and as a result, it is difficult to reduce the amount of intrusion heat transmitted through the cylindrical portion 19 to a desired level. Become.

  On the other hand, in the test mode 100, when the intermediate heat transfer section 27 and the annular protrusion 30 are disposed at positions corresponding to the temperature gradient G of the tubular section 19, local heat shrinkage is reduced and stress concentration is prevented. It is possible to reduce the load applied to the cylindrical portion 19 (see FIG. 6C). In the present embodiment, the intermediate heat transfer portion 27 and the annular protrusion 30 are located at positions where the constant temperature Ts (for example, −190 ° C.) of the intermediate heat transfer portion 27 and the annular protrusion 30 corresponds to the temperature gradient G of the tubular portion 19. As a result, an excessive load is prevented from being applied to the cylindrical portion 19. Note that the position where the constant temperature Ts of the intermediate heat transfer section 27 and the annular protrusion 30 corresponds to the temperature gradient G of the cylindrical section 19 is the temperature distribution of the cylindrical section 19 (in this embodiment, the temperature gradient G). And the temperature at which the constant temperature Ts of the intermediate heat transfer section 27 coincides, and the cylindrical portion 19 thinned to reduce the amount of heat penetration to a desired level, withstands heat shrinkage due to temperature difference in strength. It means to allow an error in the range to obtain.

  An example of a position where the above-described constant temperature Ts corresponds to the temperature gradient G of the cylindrical portion 19 will be specifically described (see FIGS. 3 and 5). For example, the temperature difference between the temperature of the upper end portion 19a of the cylindrical portion 19 and the constant temperature Ts is ΔTa, and the temperature difference between the temperature of the lower end portion 19b of the cylindrical portion 19 and the constant temperature Ts is ΔTb. Moreover, the distance from the upper end part 19a to the intermediate heat transfer part 27 is set to Xa, and the distance from the lower end part 19b to the intermediate heat transfer part 27 is set to Xb. In the present embodiment, the distances Xa and Xb from the upper end portion 19a or the lower end portion 19b to the intermediate heat transfer portion 27 are based on the contact point between the intermediate heat transfer portion 27 and the annular protrusion 30. Specifically, the distance Xa from the upper end portion 19a to the intermediate heat transfer portion 27 is a distance between the upper surface (contact surface) 27x of the intermediate heat transfer portion 27 in contact with the intermediate heat transfer portion 27 and the upper end portion 19a. A distance Xb from the lower end portion 19b to the intermediate heat transfer portion 27 is a distance between the upper surface (contact surface) 27x of the annular protrusion 30 in contact with the intermediate heat transfer portion 27 and the lower end portion 19b.

  In this case, the position corresponding to the temperature gradient G of the cylindrical portion 19 and the above-described constant temperature Ts can be a position that satisfies the condition of ΔTa / ΔTb = Xa / Xb. If ΔTa and ΔTb are determined by using this condition, the positions of the intermediate heat transfer portion 27 and the annular protrusion 30 are determined from the distance between the upper end portion 19a and the lower end portion 19b of the cylindrical portion 19, so the intermediate heat transfer portion 27 is determined. And the arrangement | positioning to the appropriate position of the cyclic | annular protrusion 30 becomes easy.

  Furthermore, the constant temperature Ts of the intermediate heat transfer section 27 according to the present embodiment is lower than the intermediate temperature of the temperature gradient G of the tubular portion 19, and therefore the intermediate heat transfer section 27 is a rotating shaft in the tubular portion 19. It is preferable that the nozzles 13 are arranged closer to the impeller 12 side than the center in the direction of the axis La (rotational axis direction). Furthermore, when the distance from the upper end part 19a to the lower end part 19b of the cylindrical part 19 is L, it is desirable to arrange the intermediate heat transfer part 27 in the range of 2L / 3 or more from the upper end part 19a and less than L.

[Method of manufacturing heat insulation structure of cryogenic rotating machine]
As described above, when determining the arrangement of the intermediate heat transfer section 27 and the annular protrusion 30, the temperature distribution in the tubular section 19 is derived assuming the test mode 100 (see FIG. 6). Here, it is also possible to manufacture the heat insulation structure of the cryogenic rotating machine 10 so that the temperature distribution is obtained with high accuracy and the intermediate heat transfer section 27 and the annular protrusion 30 are arranged at positions corresponding to the temperature distribution. is there. However, since this temperature distribution can be approximated by a temperature gradient G that decreases from the upper end portion 19a to the lower end portion 19b of the cylindrical portion 19, in this embodiment, the temperature gradient G of the cylindrical portion 19 is derived, and the temperature The heat insulation structure of the cryogenic rotating machine 10 is manufactured so that the intermediate heat transfer section 27 and the annular protrusion 30 are disposed at a position corresponding to the gradient G.

[Operation and effect of cryogenic rotating machine according to this embodiment]
In the cryogenic rotary machine 10, the intermediate heat transfer section 27 is provided so that the temperature gradient (temperature distribution) G of the low temperature side casing section 17 and the constant temperature Ts of the intermediate heat transfer section 27 correspond to each other. That is, while effectively reducing the amount of heat intrusion by the intermediate heat transfer portion 27, the temperature difference generated between the intermediate heat transfer portion 27 and the low temperature side casing portion 17 is reduced to reduce the load on the low temperature side casing portion 17. Can be reduced. As a result, the cylindrical portion 19 of the low-temperature casing portion 17 can be easily thinned, and the amount of heat intrusion transmitted through the cylindrical portion 19 can be easily reduced sufficiently.

  In the present embodiment, the temperature distribution of the low temperature side casing portion 17 is defined as a temperature gradient G in which the temperature decreases from the outer end portion to the inner end portion of the cylindrical portion 19, and as a result, details of the temperature distribution Indexing becomes unnecessary, and appropriate arrangement of the intermediate heat transfer section 27 is facilitated.

  Further, the intermediate heat transfer section 27 according to the present embodiment is disposed closer to the impeller 12 side than the center of the cylindrical section 19 in the direction of the rotation shaft 13. In this aspect, even if the constant temperature Ts of the intermediate heat transfer section 27 is lower than the intermediate temperature of the temperature gradient (temperature distribution) G, the intermediate heat transfer section 27 can be appropriately arranged.

  The cryogenic rotating machine 10 is connected to the intermediate heat transfer section 27 so as to be able to exchange heat, and includes a cooling line 31 that circulates the sub-refrigerant Sf and maintains the intermediate heat transfer section 27 at the constant temperature Ts. In addition, the intermediate heat transfer section 27 can be maintained at a constant temperature Ts.

  Further, the intermediate heat transfer section 27 according to the present embodiment includes a cylindrical portion 27b (an example of a heat receiving portion) facing the rotating shaft 13, and the cylindrical portion 27b protrudes toward the drive motor 14 side of the partition portion 27a. A heat receiving portion 27c is provided. That is, the heat receiving portion 27c that exchanges heat with the rotating shaft 13 is disposed on the higher temperature side than the partitioning portion 27a, and the amount of heat intrusion transmitted through the rotating shaft 13 is higher than that on the rotating shaft 13. It is advantageous to be able to reduce from.

  Moreover, in the manufacturing method of the heat insulation structure of the cryogenic rotary machine 10 described above, the temperature gradient (temperature distribution) G of the low temperature side casing portion 17 is derived on the assumption that the influence of the intermediate heat transfer portion 27 is excluded. The intermediate heat transfer section 27 is provided at a position where the derived temperature gradient G and the constant temperature Ts correspond. According to this manufacturing method, the cryogenic rotating machine 10 that is also effective in reducing the amount of heat intrusion transmitted through the low-temperature side casing portion 17 while appropriately disposing the intermediate heat transfer portion 27. Can be manufactured.

  The cryogenic rotating machine 10 includes a room temperature side casing part (room temperature side casing) 16 and a heat insulating part 23 surrounding a part of the rotating shaft 13 of the impeller 12 inside. A low-temperature side casing part (low-temperature side casing) 17 including an intermediate heat-transfer part 27 that reduces the amount of heat transferred from the 16 side via the rotary shaft 13, and the intermediate heat transfer of the low-temperature side casing part 17 The temperature of the contact portion with the portion 27 corresponds to the temperature of the intermediate heat transfer portion 27. That is, while effectively reducing the amount of heat intrusion by the intermediate heat transfer portion 27, the temperature difference generated between the intermediate heat transfer portion 27 and the low temperature side casing portion 17 is reduced to reduce the load on the low temperature side casing portion 17. Can be reduced. As a result, the cylindrical portion 19 of the low-temperature casing portion 17 can be easily thinned, and the amount of heat intrusion transmitted through the cylindrical portion 19 can be easily reduced sufficiently. Note that the correspondence between the temperature of the low temperature side casing portion 17 in contact with the intermediate heat transfer portion 27 and the temperature of the intermediate heat transfer portion 27 is the contact position of the low temperature side casing portion 17 with the intermediate heat transfer portion 27. The temperature of the intermediate heat transfer section 27 coincides with that of the intermediate heat transfer section 27, and the low-temperature casing portion 17 thinned in order to reduce the amount of heat penetration to a desired level has a heat shrinkage due to a temperature difference in strength. This means that an error within a range that can withstand the above is allowed.

  As mentioned above, although embodiment was described, this invention is not limited only to the above embodiment. For example, in the above embodiment, the constant temperature maintenance of the fluid transferred at an extremely low temperature and the constant temperature maintenance of the intermediate heat transfer unit are performed using the same cooling device, and as a result, the intermediate temperature is adjusted to the constant temperature of the intermediate heat transfer unit. The aspect in which the arrangement of the heat transfer unit is determined has been described. However, the arrangement of the intermediate heat transfer section is determined first, the constant temperature of the intermediate heat transfer section is determined so as to correspond to the temperature distribution (or temperature gradient) of the casing in this arrangement, and the temperature of the refrigerant passing through the cooling line is determined. You may do it.

  The present invention can be widely used in rotating machines that transfer fluid passing through piping in a heat insulating container, and may be not only fluid transfer means such as a circulator pump but also a compressor, turbine, inducer, and the like.

3 Circulation line 3a Piping 8 Thermal insulation container 10 Cryogenic rotating machine (Rotating machine)
12 Impeller 13 Rotating shaft 14 Drive motor (drive unit)
15 Casing 16 Normal temperature side casing (normal temperature side casing)
17 Low temperature side casing (low temperature side casing)
19 Cylindrical part 19a Upper end part (outer end part)
19b Lower end (inner end)
20 Fixed flange (fixed part)
23 heat insulation part 27 intermediate heat transfer part 27a partition part 27c heat receiving part 31 cooling line Mf main refrigerant (fluid)
Sf Sub refrigerant (refrigerant)
Ts Constant temperature G Temperature gradient (temperature distribution)

Claims (8)

A rotating machine for transferring a fluid passing through a pipe in an insulated container,
An impeller disposed in the heat insulating container and transferring the fluid by rotation;
A drive unit disposed outside the heat insulating container and rotating the impeller via a rotation shaft;
A heat insulating part surrounding at least a part of the rotating shaft in the heat insulating container;
A casing that is fixed to the heat insulating container and surrounds the heat insulating portion;
An intermediate heat transfer section that divides the heat insulating section into the drive section side and the impeller side, abuts against the casing, and is maintained at a constant temperature to reduce a heat penetration amount from the drive section side to the impeller side. And comprising
In a state in which the influence of the intermediate heat transfer unit is excluded, the casing has a temperature distribution in which the temperature decreases from the drive unit side to the impeller side in the heat insulating container,
The intermediate heat transfer section is a rotating machine provided at a position where the temperature distribution of the casing corresponds to the constant temperature. The casing includes a cylindrical part that surrounds the heat insulating part, and a fixing part that is provided in the cylindrical part and is fixed to the heat insulating container.
The cylindrical portion includes an outer end portion connected to the fixed portion, and an inner end portion on the impeller side,
The rotating machine according to claim 1, wherein the temperature distribution of the casing is a temperature gradient in which the temperature decreases from the outer end portion to the inner end portion of the cylindrical portion.   The temperature difference between the outer end temperature and the constant temperature is ΔTa, the temperature difference between the inner end portion and the constant temperature is ΔTb, and the distance from the outer end portion to the intermediate heat transfer portion is Xa. When the distance from the inner end portion to the intermediate heat transfer portion is Xb, the position corresponding to the temperature gradient and the constant temperature of the casing is a position satisfying the condition of ΔTa / ΔTb = Xa / Xb The rotating machine according to claim 2, wherein   The rotary machine according to claim 2 or 3, wherein the intermediate heat transfer section is disposed closer to the impeller side than a center of the cylindrical section in the rotation axis direction.   The rotary machine according to any one of claims 1 to 4, further comprising a cooling line connected to the intermediate heat transfer section so as to be able to exchange heat and circulating a refrigerant to maintain the intermediate heat transfer section at the constant temperature. The intermediate heat transfer section includes a plate-shaped partition portion having a through-hole through which the rotating shaft passes, and a cylindrical heat receiving portion provided along the through-hole and facing the rotating shaft,
The rotary machine according to any one of claims 1 to 5, wherein the heat receiving portion is provided so as to protrude toward the drive portion side of the partition portion. A method for manufacturing a heat insulating structure of a rotating machine that transfers a fluid passing through a pipe in a heat insulating container,
The rotating machine is
An impeller disposed in the heat insulating container and transferring the fluid by rotation;
A drive unit disposed outside the heat insulating container and rotating the impeller via a rotation shaft;
A heat insulating part surrounding at least a part of the rotating shaft in the heat insulating container;
A casing that is fixed to the heat insulating container and surrounds the heat insulating portion;
An intermediate heat transfer section that divides the heat insulating section into the drive section side and the impeller side, abuts against the casing, and is maintained at a constant temperature to reduce a heat penetration amount from the drive section side to the impeller side. And comprising
Deriving the temperature distribution of the casing in which the temperature decreases from the drive unit side to the impeller side in the heat insulating container, assuming that the influence of the intermediate heat transfer unit is excluded,
A method for manufacturing a heat insulating structure of a rotary machine, wherein the intermediate heat transfer portion is provided at a position where the derived temperature distribution and the constant temperature correspond. A room temperature side casing and a heat insulating part surrounding a part of the impeller rotating shaft are included inside, and the heat insulating part has an intermediate heat transfer part for reducing the amount of heat transferred from the room temperature side casing side through the rotating shaft. A rotating machine for transferring fluid, comprising a low-temperature side casing,
The rotating machine in which the temperature of the contact portion of the low-temperature casing with the intermediate heat transfer portion corresponds to the temperature of the intermediate heat transfer portion.

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