JP5042479B2 - Air cycle refrigeration cooling system - Google Patents

Description

  The present invention relates to an air cycle refrigeration cooling system in which air is used as a refrigerant and is used in a refrigeration warehouse, a low-temperature room below zero degrees, air conditioning, and the like.

  The use of air as a refrigerant is preferable in terms of environmental protection and safety compared to the case of using chlorofluorocarbon or ammonia gas, but is insufficient in terms of characteristics as energy efficiency. However, when used in a facility that can directly blow in air, such as a refrigerated warehouse, the total cost can be reduced to the same level as existing systems by taking measures such as omitting the internal fan and defrost. there is a possibility. At present, the use of chlorofluorocarbon as a refrigerant is already restricted from the environmental viewpoint, and it is desired to avoid using other refrigerant gas as much as possible. Therefore, an air cycle refrigeration cooling system that uses air as a refrigerant has been proposed for the above-described applications (for example, Patent Document 1 and Non-Patent Document 1).

Further, it is stated that the theoretical efficiency of air cooling is equal to or higher than that of chlorofluorocarbon or ammonia gas in a deep coal region of −30 ° C. to −60 ° C. (Non-patent Document 1). However, it is also stated that obtaining the theoretical efficiency of the air cooling is not possible until there is an optimally designed peripheral device. The peripheral device is a compressor, an expansion turbine, or the like.
As the compressor and the expansion turbine, a turbine unit in which a compressor impeller and an expansion turbine impeller are attached to a common main shaft is used (Patent Document 1, Non-Patent Document 1).

In addition, as a turbine compressor which processes process gas, a turbine impeller is attached to one end of the main shaft, a compressor impeller is attached to the other end, and the main shaft is supported by a journal and a thrust bearing that is controlled by an electromagnet current. A compressor has been proposed (Patent Document 2).
In addition, although it is a proposal for a gas turbine engine, in order to avoid the thrust load acting on the rolling bearing for supporting the main shaft from shortening the bearing life, the thrust load acting on the rolling bearing should be reduced by the thrust magnetic bearing. Has been proposed (Patent Document 3).
Japanese Patent No. 2623202 Japanese Patent Application Laid-Open No. 7-91760 JP-A-8-261237 Magazine, Nikkei Mechanical, “Cooling the Air with Air”, published November 13, 1995, no 467, pp. 46-52

As described above, as the air cycle refrigeration cooling system, in order to obtain the theoretical efficiency of air cooling that is highly efficient in the deep coal region, an optimally designed compressor and expansion turbine are required.
As the compressor and the expansion turbine, a turbine unit in which the compressor wheel and the expansion turbine wheel are attached to a common main shaft as described above is used. In this turbine unit, the compressor impeller can be driven by the power generated by the expansion turbine, thereby improving the efficiency of the air cycle refrigerator.

However, in order to obtain practical efficiency, it is necessary to keep the gap between each impeller and the housing minute. The fluctuation of the gap hinders stable high-speed rotation and causes a decrease in efficiency.
In addition, a thrust force acts on the main shaft by the air acting on the compressor impeller and the turbine impeller, and a thrust load is applied to the bearing that supports the main shaft. The rotation speed of the main shaft of the turbine unit in the air cycle refrigeration cooling system is 80,000 to 100,000 rotations per minute, which is very high compared with a bearing for general use. For this reason, the thrust load as described above causes a decrease in long-term durability and life of the bearing supporting the main shaft, and decreases the reliability of the turbine unit for air cycle refrigeration cooling. Unless such a problem of long-term durability of the bearing is solved, it is difficult to put the air cycle refrigeration cooling turbine unit into practical use. However, the techniques disclosed in Patent Document 1 and Non-Patent Document 1 have not yet been solved for the deterioration of the long-term durability of the bearing against the load of the thrust load under the high-speed rotation.

  In the case where the main shaft is supported by a journal bearing made of a magnetic bearing and a thrust bearing, such as the magnetic bearing type turbine compressor of Patent Document 2, the journal bearing does not have a restriction function in the axial direction. Therefore, if there is an unstable factor in controlling the thrust bearing, it is difficult to perform stable high-speed rotation while maintaining a minute gap between the impeller and the diffuser. In the case of a magnetic bearing, there is also a problem of contact when the power is stopped.

An object of the present invention is to provide an air cycle refrigeration cooling system capable of improving the long-term durability and extending the life of a bearing that supports a main shaft of a turbine unit and improving the reliability of the system.
Another object of the present invention is to obtain a stable high-speed rotation by maintaining a small gap between each impeller of the turbine unit and the diffuser, and to obtain a high compression and expansion efficiency.

The air cycle refrigeration cooling system of the present invention includes compression by pre-compression means, cooling by heat exchanger for incoming air, compression by a compressor of a turbine unit, cooling by another heat exchanger, and by an expansion turbine of the turbine unit. An air cycle refrigeration cooling system that sequentially performs adiabatic expansion, wherein the turbine unit attaches a compressor impeller of the compressor and a turbine impeller of the expansion turbine to a common main shaft, and the compressor is driven by power generated by the turbine impeller. is intended to drive the impeller, the main shaft is rotatably supported by a bearing, the bearing, is placed the in compressor wheel and the turbine blades headway in the spindle housing accommodating said spindle, a thrust exerted on the main shaft Part or all of the force is supported by an electromagnet, Is installed so as to face both surfaces of a flange-like thrust plate made of a ferromagnetic material provided in the center of the main shaft in a non-contact manner, and the bearing is composed of two rolling bearings, each of which is an inner and outer ring. A bearing cooling air introduction path is provided in the spindle housing to flow the air at the inlet of the expansion turbine to the vicinity of the compressor side bearing. an outflow path which was flowed into the vicinity of the bearing air is caused to flow out to the inlet side of the compressor, it characterized that you provided in the main shaft.

In the air cycle refrigeration cooling system having this configuration, the inflow air is compressed by the pre-compression means, and cooling is performed by the heat exchanger while the temperature is increased by the compression. The cooled air is further compressed by the compressor of the turbine unit to increase the temperature, and is cooled again by another heat exchanger. The cooled air is cooled by another heat exchanger, led to the expansion turbine of the turbine unit, cooled to a target temperature, for example, a very low temperature of about −30 ° C. to −60 ° C., and discharged by adiabatic expansion.
The turbine unit attaches the compressor impeller and the turbine impeller of the expansion turbine to a common main shaft, and drives the compressor impeller by the power generated by the turbine impeller. Cooling can be efficiently performed with the configuration. A thrust force is applied to the main shaft of the turbine unit by the pressure of air acting on each impeller. Moreover, in a turbine unit used in an air cycle refrigeration cooling system, the rotation speed is very high, for example, about 80,000 to 100,000 rotations per minute. Therefore, when the thrust force acts on a bearing that rotatably supports the main shaft, the long-term durability of the main shaft decreases.

  Since the thrust force is supported by an electromagnet in the present invention, the thrust force acting on the rotation support bearing of the main shaft is reduced while suppressing an increase in torque in a non-contact manner, improving the long-term durability of the bearing and improving the service life. An improvement is obtained. Because of the support by the electromagnet, unlike the permanent magnet, it is also possible to control the appropriate electromagnetic attraction force according to the thrust force acting on the main shaft. Since the long-term durability of the main shaft bearing is improved, the reliability of the entire air cycle refrigeration cooling system is improved. Thus, since the long-term durability and reliability of the main shaft bearing of the turbine unit, which is a bottleneck of the air cycle refrigeration cooling system, are improved, the air cycle refrigeration cooling system can be put to practical use.

In this invention, the turbine unit for air cycle refrigeration cooling includes a compressor wheel of the compressor, a turbine wheel of the expansion turbine, and a motor rotor attached to a common main shaft, and a main shaft by a magnetic force from a motor stator facing the motor rotor. The compressor impeller may be driven by rotating the compressor wheel.
When the main shaft is driven by providing a motor, it is not necessary to provide pre-compression means such as a blower before the compressor.

The bearing that supports the main shaft may be a rolling bearing. The rolling bearing preferably has a function of holding the axial position between the inner and outer rings, such as a deep groove ball bearing. Further, it may be an angular ball bearing.
In order to ensure the efficiency of compression and expansion of the turbine unit, it is necessary to keep the gap between each impeller and the housing minute. In an air cooling system, ensuring this efficiency is important. On the other hand, when the main shaft of the impeller is supported by the rolling bearing, the main shaft position is regulated by the axial position control function of the rolling bearing, and the minute gaps between the respective impellers and the housing can be kept constant. In the case of such a rolling bearing having a function of regulating the axial position, there is a problem in that long-term durability is deteriorated due to the thrust force of the bearing that rotates at a high speed. However, since the thrust force is supported by an electromagnet, Durability can be secured. As described above, since the radial support of the main shaft is performed by the rolling bearing and the thrust force is performed by the electromagnet, stable high speed rotation of the main shaft can be obtained while maintaining a minute clearance of the impeller.

  The rolling bearing is preferably grease lubricated. In the air cycle refrigeration cooling system, air serving as a cooling medium is directly sent to a space to be cooled such as a freezer. Therefore, when oil lubrication is used, there is a risk that mist of the lubricating oil may contaminate the cooling air. Due to the grease lubrication, the problem of such contamination of the air to be cooled is reduced.

  A compressor impeller and a turbine impeller in the turbine unit may be provided at both ends of the main shaft, and a bearing and an electromagnet for supporting the main shaft may be installed between the compressor impeller and the turbine impeller in the spindle housing. Since the main shaft length can be shortened by placing main members between the compressor impeller and the turbine impeller, even more stable high-speed rotation can be obtained.

When bearings are provided on both sides, a non-contact seal is provided between at least one of the outer periphery of the main shaft and the spindle housing between the compressor wheel and the nearby bearing and between the turbine wheel and the nearby bearing. May be provided.
By providing a non-contact seal, it is possible to prevent air from leaking from the contact surfaces between the bearings and the spindle housing due to the pressure difference between the compressor and the expansion turbine. Fouling by passing air and drying of the lubricant are prevented.

Said air inlet of the expansion turbine, by providing the bearing cold却空introduction channel to flow to the vicinity of the compressor side of the bearing, the temperature rise of bearing a high temperature by the high-speed rotation can be suppressed with a simple configuration, the bearing The service life and grease life are improved.

Said air flow to the vicinity of the compressor side of the bearing by providing the inlet to flow out to the outlet side passage of the compressor, the air flow from the cooling air introduction path to the bearing are improved, the cooling effect of the bearing improves.

In this invention, you may provide the sensor which detects the thrust force which acts on the said main shaft with the air in the said compressor and an expansion turbine, and the controller which controls the bearing force by the said electromagnet according to the output of this sensor.
By controlling the bearing force by the electromagnet, the bearing that supports the main shaft in rotation can be used in an optimum state against the thrust force, and the bearing can be further improved in high-speed stability, long-term durability, and long life. The reliability of the system is further improved.

The controller may be attached to the spindle housing.
By attaching the controller to the spindle housing, the connection between the electromagnet, sensor and controller can be simplified and the system can be made compact.

  In the present invention, the controller and the outside may be connected to a power line or a communication line. This makes it easy to control and monitor the turbine unit from the outside, and enables stable system operation.

The air cycle refrigeration cooling system according to the present invention compresses incoming air by pre-compression means, cools by a heat exchanger, compresses by a compressor of a turbine unit, cools by another heat exchanger, and by an expansion turbine of the turbine unit. An air cycle refrigeration cooling system that sequentially performs adiabatic expansion, wherein the turbine unit has a compressor impeller of the compressor and a turbine impeller of the expansion turbine attached to a common main shaft, and the compressor is driven by power generated by the turbine impeller. is intended to drive the impeller, the main shaft is supported freely rotating by a bearing, the bearing, installed in the compressor wheel and the turbine blades headway in the spindle housing accommodating said spindle, according to the main shaft A part or all of the thrust force is supported by an electromagnet. The stone is installed so as to be opposed to both surfaces of a flange-shaped thrust plate made of a ferromagnetic material provided in the center of the main shaft, and the bearing is composed of two rolling bearings, each of which is an inner and outer bearing. A bearing cooling air introduction passage having a regulating function for returning the axial position of the wheel to the neutral position, and allowing the air at the inlet portion of the expansion turbine to flow in the vicinity of the bearing on the compressor side is provided in the spindle housing; order to provided an outflow path for discharging the shed to the vicinity of the side of the bearing air to the inlet side of the compressor in the main shaft, the improvement of long-term durability of the bearing supporting the main shaft of the turbine unit, an extended service life As a result, the reliability of the system can be improved.
In the air cycle refrigeration cooling system of the present invention, instead of providing the precompression means, the turbine unit attaches the compressor impeller of the compressor and the turbine impeller of the expansion turbine and the motor rotor to a common main shaft, and attaches the motor rotor to the motor rotor. Even when the compressor wheel is driven by rotating the main shaft by the magnetic force from the opposed motor stator, the long-term durability of the bearing that supports the main shaft of the turbine unit can be improved and the service life can be extended. The reliability can be improved.

A first reference proposal example will be described with reference to FIGS. FIG. 1 shows the overall configuration of an air cycle refrigeration cooling system. This air cycle refrigeration cooling system is a system that directly cools air in a space to be cooled 10 such as a freezer as a refrigerant, and an air circulation path from an air intake port 1a to a discharge port 1b respectively opened in the space to be cooled 10 1 In this air circulation path 1, pre-compression means 2, first heat exchanger 3, dehumidifier 4, compressor 6 of air cycle refrigeration cooling turbine unit 5, second heat exchanger 8, intermediate heat exchanger 9, And the expansion turbine 7 of the said turbine unit 5 is provided in order. The intermediate heat exchanger 9 exchanges heat between the inflow air near the intake port 1a in the same air circulation path 1 and the air that has been heated by the subsequent compression and cooled. The air in the vicinity of 1a passes through the heat exchanger 9a.

  The pre-compression means 2 comprises a blower or the like and is driven by a motor 2a. The first heat exchanger 3 and the second heat exchanger 8 have heat exchangers 3a and 8a for circulating a cooling medium, respectively, and a cooling medium such as water and an air circulation path in the heat exchangers 3a and 8a. Heat exchange with 1 air. Each of the heat exchangers 3 a and 8 a is connected to the cooling tower 11 by piping, and the cooling medium whose temperature is increased by heat exchange is cooled by the cooling tower 11.

  This air cycle refrigeration cooling system is a system that keeps the space 10 to be cooled at about 0 ° C. to −60 ° C., and from the space to be cooled 10 to the intake port 1a of the air circulation path 1 at about 0 to −60 ° C. Air flows in. Note that the numerical values of temperature and atmospheric pressure shown below are examples that serve as a guide. The air that has flowed into the intake port 1a is used by the intermediate heat exchanger 9 to cool the downstream air in the air circulation path 1 and is heated to 30 ° C. The heated air remains at 1 atm, but is compressed to 1.4 atm by the pre-compression means 2, and the temperature is raised to 70 ° C. by the compression. Since the 1st heat exchanger 3 should just cool the air of 70 degreeC which raised temperature, even if it is cold water about normal temperature, it can cool efficiently and it cools to 40 degreeC. The dehumidifier 4 prevents the moisture in the air in the air circulation path 1 from freezing due to cooling below the freezing point in the subsequent stage and causing clogging of the air circulation path 1 and galling of the expansion turbine 7. Dehumidify the air.

The air at 40 ° C. and 1.4 atm after dehumidification is compressed to 1.8 atm by the compressor 6 of the turbine unit 5, and the second heat exchanger 8 is heated to about 70 ° C. by this compression. To 40 ° C. The 40 ° C. air is cooled to −20 ° C. by the −30 ° C. air in the intermediate heat exchanger 9. The atmospheric pressure is maintained at 1.8 atmospheric pressure discharged from the compressor 6.
The air cooled to −20 ° C. by the intermediate heat exchanger 9 is adiabatically expanded by the expansion turbine 7 of the turbine unit 5, cooled to −55 ° C., and discharged from the outlet 1 b to the cooled space 10. This air cycle refrigeration cooling system performs such a refrigeration cycle.

  FIG. 2 shows a specific example of the turbine unit 5 for air cycle refrigeration cooling. The turbine unit 5 includes a compressor 6 and an expansion turbine 7. A compressor impeller 6 a of the compressor 6 and a turbine impeller 7 a of the expansion turbine 7 are respectively attached to both ends of the main shaft 13. Further, the compressor impeller 6a is driven by the power generated in the turbine impeller 7a, and no other drive source is provided.

As will be described later with reference to FIG. 8, the compressor impeller 6 a of the compressor 6, the turbine impeller 7 a of the expansion turbine 7, and the motor rotor 92 are attached to the common main shaft 13, and the main shaft 13 is driven by the driving force of the motor 90. Also good. When the motor 90 is provided to drive the main shaft 13 , it is not necessary to provide the pre-compression means 2 (FIG. 1) such as a blower before the compressor 6.

In FIG. 2, the compressor 6 has a housing 6b that opposes the compressor impeller 6a with a small gap d1, and compresses the air sucked in the axial direction from the suction port 6c at the center by the compressor impeller 6a. Then, it is discharged from the outlet (not shown) of the outer peripheral portion as shown by an arrow 6d.
The expansion turbine 7 has a turbine housing 7b that is opposed to the turbine impeller 7a via a minute gap d2, and the air sucked from the outer peripheral portion as indicated by an arrow 7c is adiabatically expanded by the turbine impeller 7a, It discharges in the axial direction from the outlet 7d of the part.

  In the turbine unit 5, the main shaft 13 is supported by a plurality of bearings 15 and 16 in the radial direction, and the thrust force applied to the main shaft 13 is supported by an electromagnet 17. The turbine unit 5 includes a sensor 18 that detects a thrust force acting on the main shaft 13 by the air in the compressor 6 and the expansion turbine 7, and a controller 19 that controls the bearing force by the electromagnet 17 in accordance with the output of the sensor 18. have. The electromagnet 17 is installed in the spindle housing 14 so as to face the both surfaces of a flange-like thrust plate 13a made of a ferromagnetic material provided at the center of the main shaft 13 without contact.

The bearings 15 and 16 for supporting the main shaft 13 are rolling bearings and have a function of regulating the axial position, and for example, deep groove ball bearings are used. In the case of a deep groove ball bearing, it has a thrust support function in both directions, and has the effect of returning the axial position of the inner and outer rings to the neutral position. These two bearings 15 and 16 are arranged in the vicinity of the compressor impeller 6a and the turbine impeller 7a in the spindle housing 14, respectively.
The bearing 16 on the installation side of the sensor 18 is fitted in a bearing housing 23 fitted in the spindle housing 14.

The main shaft 13 is a stepped shaft having a large-diameter portion 13b at the center and small-diameter portions 13c at both ends. The bearings 15 and 16 on both sides have their inner rings 15a and 16a fitted into the small diameter portion 13c in a press-fit state, and one of the width surfaces engages with a stepped surface between the large diameter portion 13b and the small diameter portion 13c.
The portions of the spindle housing 14 closer to the impellers 6a and 7a than the bearings 15 and 16 on both sides are formed with an inner diameter surface close to the main shaft 13, and non-contact seals 21 and 22 are formed on the inner diameter surface. Yes. The non-contact seals 21 and 22 are labyrinth seals in which a plurality of circumferential grooves are arranged in the axial direction on the inner diameter surface of the spindle housing 14.

  In the air cycle refrigeration cooling system, the turbine unit 5 having this configuration compresses air as a cooling medium by the compressor 5 to increase the temperature, and the air cooled by the heat exchangers 8 and 9 is supplied to the target by the expansion turbine 7. It is used to cool and discharge by adiabatic expansion to a temperature, for example, to a very low temperature of about -30 ° C to 60 ° C.

In this turbine unit 5, the compressor impeller 6a and the turbine impeller 7a are attached to a common main shaft 13, and the compressor impeller 6a is driven by the power generated in the turbine impeller 7a, so that no power source is required. Cooling can be efficiently performed with a compact configuration.
In order to secure the efficiency of compression and expansion of the turbine unit 5, it is necessary to keep the gaps d1 and d2 between the impellers 6a and 7a and the housings 6b and 7b minute. In the air cycle refrigeration cooling system, ensuring this efficiency is important. On the other hand, since the main shaft 13 is supported by the rolling bearings 15 and 16, the axial position of the main shaft 13 is regulated to some extent by the restriction function of the axial position of the rolling bearing, and the impellers 6a and 7a The minute gaps d1 and d2 between the housings 6b and 7b can be kept constant.

However, a thrust force is applied to the main shaft 13 of the turbine unit 5 by the pressure of air acting on the impellers 6a and 7a. Further, the turbine unit 5 used in the air cooling system rotates at a very high speed of about 80,000 to 100,000 rotations per minute, for example. Therefore, when the thrust force acts on the rolling bearings 15 and 16 that rotatably support the main shaft 13, the long-term durability of the bearings 15 and 16 decreases.
In this embodiment, since the thrust force is supported by the electromagnet 17, the thrust force acting on the rolling bearings 15 and 16 for supporting the main shaft 13 can be reduced while suppressing an increase in torque without contact. In this case, a sensor 18 for detecting a thrust force acting on the main shaft 13 by the air in the compressor 6 and the expansion turbine 7 and a controller 19 for controlling the bearing force by the electromagnet 17 according to the output of the sensor 18 are provided. Therefore, the rolling bearings 15 and 16 can be used in an optimum state with respect to the thrust force according to the bearing specifications.
In particular, since the sensor 18 is arranged in the vicinity of the bearing 16, the thrust force acting on the bearing 16 in question can be directly measured, the measurement accuracy is good, and the thrust force can be precisely controlled. .

  Therefore, stable high-speed rotation of the main shaft 13 can be obtained while maintaining appropriate gaps d1 and d2 between the impellers 6a and 7a, and the long-term durability and life of the bearings 15 and 16 can be improved. Since the long-term durability of the bearings 15 and 16 is improved, the reliability of the entire air cycle refrigeration cooling turbine unit 5 and, as a whole, the air cycle refrigeration cooling system is improved. As described above, stable high-speed rotation, long-term durability, and reliability of the main shaft bearings 15 and 16 of the turbine unit 5 that are the bottleneck of the air cycle refrigeration cooling system are improved. It becomes possible.

  The bearings 15 and 16 are disposed in the vicinity of the compressor impeller 6a and in the vicinity of the turbine impeller 7a, and the main shaft 13 is supported at both ends, so that more stable high-speed rotation is possible.

  Since non-contact seals 21 and 22 are provided between the main shaft 13 and the spindle housing 14 on the end side of the bearings 15 and 16, air passes through the bearings 15 and 16 and the like with the compressor 6. Leakage between the expansion turbines 7 is prevented. Since there is a large pressure difference between the inside of the compressor 6 and the inside of the expansion turbine 7, the inside of each bearing 15, 16 and the surface on which the inner and outer rings 15 a, 16 a of each bearing 15, 16 are fitted to the main shaft 13 and the spindle housing 14. Air leaks are about to occur. Such air leakage causes the efficiency of the compressor 6 and the expansion turbine 7 to decrease, and the air passing through the bearings 15 and 16 contaminates the bearings 15 and 16 when there is dust, or lubricates the bearings. There is a risk that the material may be dried to reduce durability. Such a decrease in efficiency and the fouling of the bearings 15 and 16 are prevented by the non-contact seals 21 and 22.

Each of FIGS. 3 and later, other references proposed examples and illustrates the implementation form that put in this invention. In each example after FIG. 3, the configuration and effects are the same as those in the example of FIG. 2 except for the matters specifically described, and the same reference numerals are given to the corresponding parts, and redundant explanations are omitted.

Figure 3 shows a turbine unit 5 definitive other reference proposed example. This turbine unit 5 has a main shaft 13 that is hollow, and an output side of the expansion turbine 7 and an input side of the compressor 6 communicate with each other through a vent hole 83 that serves as a bearing cooling air introduction path in the main shaft 13. is there.
When the vent hole 83 is provided in the main shaft 13 as described above, the main shaft 13 is cooled by the air passing through the vent hole 83, and the bearings 15 and 16 that become high temperature by high-speed rotation are cooled by heat conduction from the main shaft 13. The For this reason, the durability of the bearings 15 and 16 is improved.

  The vent hole 83 penetrating the main shaft 13 may be provided with branch paths 83a and 83b that open to the outer peripheral surface of the main shaft 13 in the vicinity of the bearings 15 and 16 as shown in FIG. When these branch paths 83a and 83b are provided, the bearings 15 and 16 are directly cooled by the air flowing through the branch paths 83a and 83b, and the cooling efficiency of the bearings 15 and 16 is improved.

FIG. 5 shows a turbine unit 5 in still another reference proposal example . The turbine unit 5 includes a bearing cooling air introduction path 84 that opens from the shaft end of the main shaft 13 on the compressor impeller 6a side to the main shaft central side of the bearing 15 in the vicinity thereof, and the shaft end of the main shaft 13 on the turbine impeller 7a side. Therefore, a bearing cooling air introduction passage 85 that opens to the center side of the main shaft of the bearing 16 in the vicinity thereof is provided.
In the case of this configuration, the air in the compressor 6 flows into the vicinity of the bearing 15 on the compressor 6 side via the bearing cooling air introduction path 84, and after cooling the bearing 15 and the bearing 16, the bearing cooling air introduction path 85 is passed through. To the expansion turbine side.

  In addition, since the vicinity of the expansion turbine 7 is relatively low in temperature, the temperature rise is suppressed even if the bearing 16 rotates at a high speed. Therefore, as shown in FIG. 6, the bearing cooling air introduction path 84 may be provided only on the compressor 6 side.

FIG. 7 shows the turbine unit 5 in the embodiment of the present invention . This turbine unit 5 is provided with a bearing cooling air introduction passage 86 in the spindle housing 84 for flowing air at the inlet of the expansion turbine 7 to the vicinity of the bearing on the compressor 6 side. In addition, an outflow path 87 through which the introduced air flows out to the inlet side of the compressor 6 is provided in the main shaft 13.
Since the pressure at the inlet of the expansion turbine 7 is the pressure after compression by the compressor 6, it is higher than the pressure at the inlet of the compressor 6. For this reason, the air flow which flows in from the said bearing cooling air introduction path 86 and flows out out of the outflow path 87 arises. The air at the inlet of the expansion turbine 7 is air cooled through the second heat exchanger 8 and the intermediate heat exchanger 9 in FIG. 1 and has a low temperature of about −40 ° C., for example. Since the bearing 15 on the compressor 6 side is cooled by the low-temperature air, the compressor-side bearing 15 that tends to become high temperature by high-speed rotation can be efficiently cooled, and durability can be improved.

  FIG. 8 shows a turbine unit 5 in still another embodiment. The turbine unit 5 is provided with a motor 90 that rotationally drives the main shaft 13. The motor 90 is provided side by side with the electromagnet 17 and includes a stator 91 provided on the spindle housing 14 and a rotor 92 provided on the main shaft 13. The stator 91 has a stator coil 91a, and the rotor 92 is made of a magnet or the like. The motor 90 is controlled by a motor controller 93.

  In the turbine unit 5, the compressor impeller 6 a is rotationally driven by the driving force of the turbine impeller 7 a generated in the expansion turbine 7 and the driving force of the motor 90. Therefore, the compressor 6 can be driven without the pre-compression means 2 composed of the blower of FIG. 1, and the system can be made compact.

FIG. 9 shows a turbine unit 5 in still another embodiment. This structure is a configuration in which a controller 19 is built in the turbine unit 5. With this configuration, the cable between the controller 19 and the electromagnet 17 and the cable between the controller 19 and the sensor 18 can be shortened, and the connection is simple, which is advantageous in terms of cost, and at the same time, an external sensor circuit system. The overall configuration can be made compact.
As shown in FIG. 10, in the configuration in which the motor 90 is arranged in the turbine unit 5, the cable between the motor 90 and the controller 19 </ b> A is also required by incorporating the controller 19 </ b> A in the turbine unit 5. The configuration in which the controller 19A is built in the unit 5 is further advantageous. The controller 19A in this embodiment includes the controller 19 and the motor controller 93.
By adopting a configuration in which not only the power supply line but also the communication line is connected to the controller 19A from the outside, the operating state of the electromagnet 17 can be changed from the outside. For example, when the main shaft 13 is not rotating, it is configured so that no current is supplied to the electromagnet 17 by an external control signal, thereby avoiding unnecessary power supply to the turbine unit 5 and saving energy. Is possible. Further, by sending the output of the sensor 18 to the outside through the communication line, it is possible to monitor the state of the turbine unit based on the sensor output outside.

In each of the above embodiments, the electromagnet 17 is provided on the thrust plate 13a of the main shaft 13, but a permanent magnet (not shown) may be provided in addition to the electromagnet 17. Further, if the unnecessary control of the scan last power as reference Proposed Example, it can also be adapted to support a thrust force of the main shaft 13 only at the permanent magnets.

It is a systematic diagram of the air cycle refrigeration cooling system concerning the 1st reference proposal example . It is sectional drawing of the turbine unit for air cycle refrigeration cooling used for the air cycle refrigeration cooling system. It is sectional drawing of the turbine unit for air cycle refrigeration cooling of the air cycle refrigeration cooling system in the other reference proposal example . It is sectional drawing of the turbine unit for air cycle refrigeration cooling in the other reference proposal example . It is sectional drawing of the turbine unit for air cycle refrigeration cooling in the other reference proposal example . It is sectional drawing of the turbine unit for air cycle refrigeration cooling in the other reference proposal example . It is sectional drawing of the turbine unit for air cycle refrigeration cooling in embodiment of this invention . It is sectional drawing of the turbine unit for air cycle refrigeration cooling in other embodiment. It is sectional drawing of the turbine unit for air cycle refrigeration cooling in other embodiment. It is sectional drawing of the turbine unit for air cycle refrigeration cooling in other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Air circulation path 1a ... Intake port 1b ... Exhaust port 2 ... Precompression means 3 ... 1st heat exchanger 5 ... Air cycle refrigeration cooling turbine unit 6 ... Compressor 6a ... Compressor impeller 7 ... Expansion turbine 7a ... Turbine blade Car 8 ... Second heat exchanger 9 ... Intermediate heat exchanger 10 ... Space to be cooled 13 ... Main shaft 13a ... Thrust plate 14 ... Spindle housing 15, 16 ... Bearing 17 ... Electromagnet 18 ... Sensors 19, 19A ... Controllers 21 and 22 ... Non-contact seal 83 ... Ventilation path 84, 85 ... Bearing cooling air introduction path 86 ... Bearing cooling air introduction path 70 ... Outflow path 90 ... Motor 93 ... Motor controller

Claims (10)

Air cycle refrigeration cooling that sequentially performs compression by precompression means, cooling by a heat exchanger, compression by a compressor of the turbine unit, cooling by another heat exchanger, and adiabatic expansion by the expansion turbine of the turbine unit with respect to the incoming air. A system,
The turbine unit attaches the compressor impeller of the compressor and the turbine impeller of the expansion turbine to a common main shaft, and drives the compressor impeller by power generated by the turbine impeller, and the main shaft is rotated by a bearing. freely and supported, the bearing, the installed in the compressor wheel and the turbine blades headway in the spindle housing accommodating said spindle, a part or all of the thrust force exerted on the main shaft and supported by an electromagnet, the electromagnet The bearing is installed so as to face the flange-shaped thrust plate made of a ferromagnetic material provided in the center of the main shaft in a non-contact manner. The bearing is composed of two rolling bearings, and the inner and outer rings are axial. Has a regulation function to return the direction position to the neutral position ,
A bearing cooling air introduction path is provided in the spindle housing for flowing the air at the inlet of the expansion turbine to the vicinity of the bearing on the compressor side, and the air flowed to the vicinity of the bearing on the compressor side is provided on the inlet side of the compressor air cycle refrigeration cooling system the outflow route is characterized that you provided in the main shaft to flow to the. An air cycle refrigeration cooling system that sequentially performs compression by a compressor of a turbine unit, cooling by a heat exchanger, cooling by another heat exchanger, and adiabatic expansion by an expansion turbine of the turbine unit with respect to inflow air,
The turbine unit is configured such that the compressor impeller of the compressor and the turbine impeller of the expansion turbine and the motor rotor are attached to a common main shaft, and the main shaft is rotated by a magnetic force from a motor stator opposed to the motor rotor. is intended to drive the, the main shaft is rotatably supported by a bearing, the bearing, the installed in the compressor wheel and the turbine blades headway in the spindle housing accommodating said spindle, the thrust force exerted on the main shaft Part or all is supported by an electromagnet, and this electromagnet is installed so as to face the flange-shaped thrust plate made of a ferromagnetic material provided at the center of the main shaft in a non-contact manner. Consisting of two rolling bearings, the axial position of the inner and outer rings is the neutral position. It has a regulatory function to return,
A bearing cooling air introduction path is provided in the spindle housing for flowing the air at the inlet of the expansion turbine to the vicinity of the bearing on the compressor side, and the air flowed to the vicinity of the bearing on the compressor side is provided on the inlet side of the compressor air cycle refrigeration cooling system the outflow route is characterized that you provided in the main shaft to flow to the.   3. The air cycle refrigeration cooling system according to claim 1, further comprising: a sensor that detects a thrust force acting on the main shaft; and a controller that controls a bearing force of the electromagnet according to an output of the sensor.   4. The air cycle refrigeration cooling system according to claim 1, wherein the bearing comprises a grease lubricated rolling bearing. 5.   The air cycle refrigeration cooling system according to any one of claims 1 to 4, wherein a sensor for detecting a thrust force acting on the main shaft is disposed on a stationary side in the vicinity of the bearing.   6. The compressor impeller and the turbine impeller according to claim 1, wherein the compressor impeller and the turbine impeller are provided at both ends of a main shaft, and the bearing and the electromagnet are connected to the compressor impeller and the turbine in a spindle housing. Air cycle refrigeration cooling system installed between impellers.   7. A non-contact seal is provided in at least one of the outer periphery of the main shaft and the spindle housing between the compressor impeller and a nearby bearing and between the turbine impeller and the neighboring bearing. Air cycle refrigeration cooling system.   The air cycle refrigeration cooling system according to claim 7, wherein a labyrinth seal having a plurality of circumferential grooves is provided as the non-contact seal. The sensor according to any one of claims 1 to 8 , further comprising: a sensor that detects a thrust force acting on the main shaft; and a controller that controls a bearing force of the electromagnet according to an output of the sensor. Air cycle refrigeration cooling system attached to the spindle housing. 10. The air cycle refrigeration cooling system according to claim 9, wherein the connection between the controller and the outside includes a power supply line or a communication line.

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