JP5986453B2 - Brayton cycle engine - Google Patents

Description

  The present invention relates to a Brayton cycle engine.

  Conventionally, for example, the following Patent Document 1 is known as a technical document related to a Brayton cycle engine for exhaust heat regeneration. Patent Document 1 discloses a scroll-type Brayton cycle engine including a scroll-type compressor that compresses a working medium and a scroll-type expander that expands the working medium.

International Publication WO2005 / 080756 Pamphlet

  By the way, in the Brayton cycle engine, not only the improvement of the efficiency of exhaust heat regeneration but also the downsizing and integration for arranging in a small space are strongly desired. In this regard, the conventional Brayton cycle engine still has room for improvement.

  Therefore, an object of the present invention is to provide a Brayton cycle engine that can improve the efficiency of exhaust heat regeneration and is advantageous for downsizing and integration.

In order to solve the above problems, the present invention is a Brayton cycle engine having a plurality of screw rotors arranged in a casing, the first reference screw rotor and the second reference screw rotor rotating integrally, By rotating in a state of being engaged with the first reference screw rotor, the working medium is expanded by rotating in a state of being engaged with the compression screw rotor in which the working medium is compressed and being engaged with the second reference screw rotor. An expansion screw rotor that is carried while the working medium compressed in the compression screw rotor flows toward the heater, and a second flow path that the working medium expanded in the expansion screw rotor flows toward the cooler and a regenerator having, in a casing, a first reference screw rotor And a compression chamber in which a compression screw rotor is arranged, and an expansion chamber in which a second reference screw rotor and an expansion screw rotor are arranged, and the first reference screw rotor and the second reference screw rotor are: The heater rotates integrally with the reference rotation shaft extending over both the compression chamber and the expansion chamber, and the heater is arranged on the expansion chamber side of the casing in a direction orthogonal to the extending direction of the reference rotation shaft as viewed from the casing. The cooler is arranged on the compression chamber side of the casing in a direction orthogonal to the extending direction of the reference rotation shaft as viewed from the casing, and the regenerator is a direction orthogonal to the extending direction of the reference rotation shaft as viewed from the casing. a is disposed to the heater and cooler different directions, it extends over both of the compression chambers and expansion chamber of the casing, operating medium in the regenerator, inflated with compressed working medium DOO, characterized in that the flow in opposite directions.

  According to the Brayton cycle engine according to the present invention, the configuration can be integrally arranged as compared with the conventional Brayton cycle engine by adopting a configuration in which the working medium is compressed or expanded using a plurality of screw rotors. This is advantageous for downsizing. Moreover, according to this Brayton cycle engine, the heat exchanger in which the compressed working medium and the expanded working medium flow in directions opposite to each other is provided, so that the low-temperature working medium and the cooler before entering the heater can be provided. Since heat exchange of the high-temperature working medium before entering can be performed efficiently, the efficiency of exhaust heat regeneration can be improved. Therefore, according to this Brayton cycle engine, the efficiency of exhaust heat regeneration can be improved, which is advantageous for downsizing and integration.

The Brayton cycle engine according to the present invention may further include a generator connected to the rotating shaft of the compression screw rotor or the rotating shaft of the first reference screw rotor, and the generator may be cooled by a cooler .
According to this Brayton cycle engine, it becomes possible to take out the rotational power of a screw rotor as electric power by providing a generator. In this Brayton cycle engine, the generator is connected to the rotating shaft of the compression screw rotor or the first reference screw rotor so that the generator can be cooled by a cooler disposed in the vicinity of the compression screw rotor. The According to this configuration, the cooling pipe of the generator can be shortened, which contributes to the downsizing of the Brayton cycle engine.

In the Brayton cycle engine according to the present invention, the rotation shaft of the compression screw rotor and the rotation shaft of the expansion screw rotor may be arranged on the same axis.
According to this Brayton cycle engine, by arranging the rotation shafts of the compression screw rotor and the expansion screw rotor on the same axis line, the configuration of the casing can be simplified as compared with the case where the rotation shafts are shifted and arranged. This is advantageous for downsizing and integration of the engine.

In the Brayton cycle engine according to the present invention, the compression screw rotor and the expansion screw rotor may have a common rotating shaft.
According to this Brayton cycle engine, since the rotation shafts of the compression screw rotor and the expansion screw rotor are made common, the number of thrust bearings that receive the axial force of the rotation shaft can be reduced, so that the configuration of the engine is simplified. And it is advantageous for cost reduction.

  ADVANTAGE OF THE INVENTION According to this invention, the efficiency of exhaust heat regeneration can be improved and the Brayton cycle engine advantageous to size reduction and integration can be provided.

1 is a schematic plan view showing a Brayton cycle engine according to a first embodiment. It is a schematic side view which shows the Brayton cycle engine of FIG. It is a schematic sectional drawing which shows the Brayton cycle engine of FIG. 1 seen from the rotating shaft direction. It is a schematic plan view which shows the Brayton cycle engine which concerns on 2nd Embodiment. It is a schematic side view which shows the Brayton cycle engine of FIG. (A) It is a schematic sectional drawing in alignment with the VIa-VIa line | wire of FIG. (B) It is a schematic sectional drawing in alignment with the VIb-VIb line | wire of FIG. It is a schematic plan view which shows the Brayton cycle engine which concerns on 3rd Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

[First Embodiment]
The Brayton cycle engine 1 according to the first embodiment shown in FIGS. 1 to 3 is a screw-type external combustion engine that is mounted on a vehicle and regenerates exhaust heat of the engine by circulation of a working medium. The working medium is preferably a medium having a large specific heat ratio such as helium He.

  The Brayton cycle engine 1 includes a plurality of screw rotors 3 to 5 housed in a casing 2, a heater 6 and a cooler 7 that heat and cool a working medium compressed or expanded by the screw rotors 3 to 5, and heating A regenerator (heat exchanger) 8 that performs heat exchange of the working medium flowing in the cooler 6 or the cooler 7 and a generator 9 that converts the rotational power of the screw rotors 3 to 5 into electric power.

  The screw rotors 3 to 5 are divided into a reference screw rotor 3, a compression screw rotor 4, and an expansion screw rotor 5. Hereinafter, description will be made in order.

  The reference screw rotor 3 is a rotating body having a reference rotation shaft 10, a first reference screw rotor 11, and a second reference screw rotor 12.

  The reference rotation shaft 10 is a shaft member extending in the horizontal direction, and is rotatably supported by a bearing member attached to the wall of the casing 2. In the casing 2, a compression chamber C for compressing the working medium and an expansion chamber E for expanding the working medium are formed separately, and the reference rotation shaft 10 has the adjacent compression chamber C and expansion chamber E. Extends over both. That is, the reference rotation shaft 10 extends through the wall 2a separating the compression chamber C and the expansion chamber E. The casing 2 is a casing having sufficient heat insulation, durability, and airtightness.

  The first reference screw rotor 11 and the second reference screw rotor 12 are cylindrical portions in which screw tooth grooves (screw-like irregularities) are formed on the side surfaces. The first reference screw rotor 11 and the second reference screw rotor 12 rotate integrally with the reference rotation shaft 10.

  The first reference screw rotor 11 is provided in the compression chamber C in the casing 2 and meshes with the compression screw rotor 4. On the other hand, the second reference screw rotor 12 is provided in the expansion chamber E in the casing 2 and meshes with the expansion screw rotor 5. Note that the screw tooth groove of the first reference screw rotor 11 and the screw tooth groove of the second reference screw rotor 12 do not need to have the same shape, and may have different shapes and pitches.

  The compression screw rotor 4 is a cylindrical member that is disposed in the compression chamber C and rotates around a rotation shaft 4 a that extends in parallel with the reference rotation shaft 10. A screw tooth groove that meshes with the first reference screw rotor 11 is formed on the side surface of the compression screw rotor 4.

  The compression screw rotor 4 rotates while meshing with the first reference screw rotor 11, thereby compressing the working medium in the gap formed by the screw tooth groove of each rotor. The portion other than the portion of the compression screw rotor 4 that meshes with the first reference screw rotor 11 is covered with the casing 2 through a slight gap (for example, a gap in units of microns).

  In the compression chamber C, there are formed a compression chamber inlet Q1 and a compression chamber outlet Q2 which are outlets and outlets for the working medium. The compression chamber inlet Q1 is formed in the lower portion of the compression chamber C on the expansion chamber E side, and the compression chamber outlet Q2 is formed in the upper portion of the compression chamber C on the side opposite to the expansion chamber E (generator 9 side). Has been. The compression screw rotor 4 and the first reference screw rotor 11 carry the working medium from the compression chamber inlet Q1 toward the compression chamber outlet Q2 in the extending direction of the rotating shaft 4a.

  The screw tooth groove of the compression screw rotor 4 is formed so that a gap (clearance) formed with the screw tooth groove of the first reference screw rotor 11 becomes smaller in the working medium feeding direction (carrying direction). Thereby, the working medium in the gap between the compression screw rotor 4 and the second reference screw rotor 12 is gradually compressed while being conveyed in the heat insulating casing 2.

  The expansion screw rotor 5 is a cylindrical member that is disposed in the expansion chamber E and rotates around a rotation shaft 5 a that extends parallel to the reference rotation shaft 10. The rotation shaft 5 a of the expansion screw rotor 5 is located on the opposite side of the reference rotation shaft 10 when viewed from the rotation shaft 4 a of the compression screw rotor 4. A screw tooth groove that meshes with the second reference screw rotor 12 is formed on the side surface of the expansion screw rotor 5.

  The expansion screw rotor 5 rotates while meshing with the second reference screw rotor 12, thereby expanding the working medium in the gap formed by the screw tooth groove of each rotor. A portion of the expansion screw rotor 5 other than the portion engaged with the second reference screw rotor 12 is covered with the casing 2 through a slight gap (for example, a gap in units of microns).

  The expansion chamber E is formed with an expansion chamber inlet P1 and an expansion chamber outlet P2 that serve as the inlet / outlet of the working medium. The expansion chamber inlet P1 is formed in the lower portion of the expansion chamber E on the compression chamber C side, and the expansion chamber outlet P2 is formed in the upper portion of the expansion chamber E opposite to the compression chamber C. The expansion screw rotor 5 and the second reference screw rotor 12 carry the working medium from the expansion chamber inlet P1 toward the expansion chamber outlet P2 in the extending direction of the rotation shaft 5a. That is, the working medium in the compression chamber C and the working medium in the expansion chamber E are conveyed in a direction away from each other (a direction away from the wall 2a).

  The screw tooth groove of the expansion screw rotor 5 is formed such that a gap (clearance) formed with the screw tooth groove of the second reference screw rotor 12 is increased in the feed direction (carrying direction) of the working medium. Thereby, the working medium in the gap between the expansion screw rotor 5 and the second reference screw rotor 12 is gradually expanded while being conveyed in the heat insulating casing 2.

  The heater 6 heats the working medium at an equal pressure by using a recovered heat source (exhaust gas from a vehicle engine). The heater 6 is provided below the expansion chamber E side (expansion screw rotor 5 side) of the casing 2. The heater 6 is connected to the expansion chamber inlet P1 of the casing 2 and the regenerator 8 through a pipe. The configuration of the heater 6 is not particularly limited as long as it can transfer heat from the recovered heat source to the working medium without pressure fluctuation, and a general heat exchanger configuration can be adopted.

  The cooler 7 cools the working medium at a constant pressure with a cooling heat source (cooling water or air). The cooler 7 is provided above the compression chamber C side (compression screw rotor 4 side) of the casing 2. The cooler 7 is connected to the compression chamber inlet Q1 of the casing 2 and the regenerator 8 through a pipe. The configuration of the cooler 7 is not particularly limited as long as it can transfer heat from the working medium to the cooling heat source without pressure fluctuation, and a general heat exchanger configuration can be adopted.

  The regenerator (heat exchanger) 8 includes a first flow path 8a and a second flow path 8b through which the working medium flows, and heat exchange is performed on the working medium toward the heater 6 or the cooler 7. The regenerator 8 is provided on the side of the casing 2.

  The first flow path 8 a is a flow path through which a low-temperature working medium compressed by the compression screw rotor 4 flows, and connects the compression chamber outlet Q <b> 2 of the casing 2 and the heater 6. The second flow path 8 b is a flow path through which a high-temperature working medium expanded by the expansion screw rotor 5 flows, and connects the expansion chamber outlet P <b> 2 of the casing 2 and the cooler 7.

  The regenerator 8 has a cross flow configuration in which the working medium flowing through the first flow path 8a and the working medium flowing through the second flow path 8b flow in directions opposite to each other. The working medium in the first flow path 8a and the working medium in the second flow path 8b flow so as to oppose both in the horizontal direction and the vertical direction. The configuration of the regenerator 8 is not particularly limited as long as it is a cross flow configuration, and various general heat exchanger configurations can be adopted.

  For example, in a double pipe, one of the inner channel and the outer channel may be the first channel 8a and the other may be the second channel 8b. Each of the first flow path 8a and the second flow path 8b may be composed of one or a plurality of pipes. Each pipe may be configured to meander and increase the contact area between the flow paths.

  The generator 9 is connected to the rotating shaft 4a of the compression screw rotor 4 and converts the rotational power of the compression screw rotor 4 into electric power. Thereby, the electric power regeneration of the thermal energy of the exhaust gas is performed. The generator 9 stores the generated power in a battery or the like (not shown). The generator 9 is cooled by a cooler 7 located above the compression screw rotor 4.

  The Brayton cycle engine 1 does not necessarily include the generator 9, and may output the rotation of the screw rotors 3 to 5 as power. In this case, power can be output from any rotating shaft.

  Further, the generator 9 may be connected to the reference rotation shaft 10 of the first reference screw rotor 11 instead of the rotation shaft 4 a of the compression screw rotor 4. Even in this case, by disposing the generator 9 on the compression chamber C side, the distance from the cooler 7 can be shortened and effective cooling can be performed.

  Next, exhaust heat regeneration in the Brayton cycle engine 1 will be described with reference to the drawings.

  As shown in FIGS. 1 to 3, in the Brayton cycle engine 1, exhaust gas discharged from the vehicle engine is sent to the heater 6 as a recovery heat source, and the working medium is heated at an equal pressure in the heater 6.

  The working medium heated in the heater 6 is sent from the expansion chamber inlet P1 of the casing 2 into the expansion chamber E. In the expansion chamber E, the working medium is conveyed toward the expansion chamber outlet P2 while being expanded by the rotation of the expansion screw rotor 5 and the second reference screw rotor 12.

  In the expansion chamber E, thermal energy given to the working medium in the expansion process is recovered as power. A part of the power is used to rotate the reference screw rotor 3 and the compression screw rotor 4, and the rest is converted into electric power by the generator 9.

  The high-temperature working medium expanded in the heat insulating casing 2 is sent out from the expansion chamber outlet P2, and then flows through the second flow path 8b of the regenerator 8 toward the upper cooler 7. At this time, heat exchange is performed between the high temperature working medium flowing through the second flow path 8b and the low temperature working medium flowing through the first flow path 8a.

  In the cooler 7, the working medium is cooled at an equal pressure by exchanging heat with a cooling heat source such as cooling water. The working medium cooled in the cooler 7 is sent from the compression chamber inlet Q1 of the casing 2 into the compression chamber C.

  In the compression chamber C, the working medium is conveyed toward the compression chamber outlet Q2 while being compressed by the rotation of the compression screw rotor 4 and the first reference screw rotor 11. The low-temperature working medium compressed in the heat insulating casing 2 is sent out from the compression chamber outlet Q2, and then flows through the first flow path 8a of the regenerator 8 toward the heater 6 below. At this time, heat exchange is performed between the high temperature working medium flowing through the first flow path 8a and the low temperature working medium flowing through the second flow path 8b. Thereafter, the working medium that has entered the heater 6 is heated and circulated again.

  According to the Brayton cycle engine 1 according to the first embodiment described above, the working medium is compressed or expanded by using a plurality of screw rotors 3 to 5, compared with the conventional Brayton cycle engine. The structure can be arranged integrally, which is advantageous for downsizing.

  Moreover, the Brayton cycle engine 1 includes the regenerator 8 in which the compressed working medium and the expanded working medium flow in directions opposite to each other, thereby entering the working medium and the cooler 7 before entering the heater 6. Since heat exchange of the previous working medium can be performed efficiently, the efficiency of exhaust heat regeneration can be improved. Therefore, according to the Brayton cycle engine 1, the efficiency of exhaust heat regeneration can be improved, which is advantageous for downsizing and integration.

  Further, according to the Brayton cycle engine 1, the heater 6 and the cooler 7 are provided independently on the upper and lower sides of the casing 2, and the regenerator 8 is provided on the side of the casing 2, so that the piping design is minimized. Can be. This is advantageous for downsizing and integration of the Brayton cycle engine 1.

  Moreover, according to this Brayton cycle engine 1, by providing the generator 9, it becomes possible to take out rotation of the compression screw rotor 4 as electric power. Furthermore, in this Brayton cycle engine 1, the generator 9 can be easily connected to the rotary shaft 4a of the compression screw rotor 4 by the cooler 7 disposed in the vicinity of the compression screw rotor 4 by connecting the generator 9 to the rotary shaft 4a of the compression screw rotor 4. Can be cooled. This configuration is advantageous in reducing the size of the Brayton cycle engine 1 because the cooling pipe of the generator 9 can be shortened.

[Second Embodiment]
The Brayton cycle engine 21 according to the second embodiment shown in FIGS. 4 to 6 is different from the Brayton cycle engine 1 according to the first embodiment in that the rotation shaft 24 a of the compression screw rotor 24 and the rotation shaft of the expansion screw rotor 25. The point etc. which 25a is arrange | positioned on the same axis line differ greatly.

  In the Brayton cycle engine 21 according to the second embodiment, the axes of the rotation shaft 24a of the compression screw rotor 24 and the rotation shaft 25a of the expansion screw rotor 25 are not shifted from each other and are on the same axis. For this reason, the casing 22 can be made into a substantially rectangular parallelepiped simple shape. In addition, the rotating shaft 24a of the compression screw rotor 24 and the rotating shaft 25a of the expansion screw rotor 25 are disposed separately with a wall 22a of the casing 22 (a wall separating the compression chamber C and the expansion chamber E) interposed therebetween.

  Further, in the Brayton cycle engine 21 of the second embodiment, the flow of the working medium is different from that of the Brayton cycle engine 1 of the first embodiment. Specifically, both the heater 26 and the cooler 27 are disposed above the casing 22.

  In addition, the compression chamber inlet Q1 of the casing 22 is formed in the upper portion of the compression chamber C on the opposite side (the generator 9 side) of the expansion chamber E, and the compression chamber outlet Q2 is the expansion chamber E of the compression chamber C. It is formed in the lower part of the side. The expansion chamber inlet P1 is formed in the upper portion of the expansion chamber E on the compression chamber C side, and the expansion chamber outlet P2 is formed in the lower portion of the expansion chamber E opposite to the compression chamber C.

  The regenerator 28 is the same as in the first embodiment in that the working medium flows so as to face each other in the horizontal direction, but the point that any working medium flows from the bottom to the top in the vertical direction is different. .

  In the Brayton cycle engine 21 of the second embodiment, the generator 9 is connected to the reference rotation shaft 30 of the reference screw rotor 23. The configuration itself of the reference screw rotor 23 is the same as that of the first embodiment. The generator 9 is disposed on the compression chamber C side, that is, on the cooler 27 side.

  According to the Brayton cycle engine 21 of the second embodiment described above, the efficiency of exhaust heat regeneration can be improved by providing the regenerator 28 as in the first embodiment. Moreover, according to the Brayton cycle engine 21, the rotation shaft 4a of the compression screw rotor 4 and the rotation shaft 5a of the expansion screw rotor 5 are arranged on the same axis line, compared to the case where the rotation shafts are arranged to be shifted. The configuration of the casing 22 can be simplified, which is advantageous for downsizing and integration of the engine.

[Third Embodiment]
The Brayton cycle engine 41 of the third embodiment shown in FIG. 7 has a common rotating shaft 42 for the compression screw rotor 24 and the expansion screw rotor 25 compared to the Brayton cycle engine 21 of the second embodiment. Only the point is different.

  Specifically, the rotating shaft 42 extends through the wall 22a separating the compression chamber C and the expansion chamber E. The compression screw rotor 24 and the expansion screw rotor 25 rotate integrally with a common rotating shaft 42.

  According to the Brayton cycle engine 41 of the third embodiment described above, the rotation shaft 42 of the compression screw rotor 24 and the expansion screw rotor 25 is made common, thereby reducing the number of thrust bearings that receive the axial direction of the rotation shaft. This is advantageous for simplification of the engine configuration and cost reduction.

  The present invention is not limited to the embodiment described above. For example, the present invention is not limited to in-vehicle use, and can also be applied to a ship or other moving body or a fixed facility. Moreover, it is not always necessary to provide a generator. The working medium is not limited to He, but may be other gas or liquid.

  Further, the arrangement of the accelerator, the cooler, and the regenerator is not limited to that described above, and various arrangements can be employed.

  Furthermore, the shape of the screw rotor is not limited to that described above, and may be formed in a tapered shape, for example. Further, the arrangement of the screw rotor is not limited to that described above, and the screw rotor may be arranged so as to extend in the vertical direction.

  1, 2, 41 ... Brayton cycle engine 2, 22 ... Casing 2a, 22a ... Wall 3, 23 ... Reference screw rotor 4, 24 ... Compression screw rotor 4a, 24a ... Rotating shaft 5, 25 ... Expansion screw rotor 5a, 25a ... Rotating shaft 6, 26 ... Heater 7, 27 ... Cooler 8, 28 ... Regenerator 8a, 28a ... First flow path 8b, 28b ... Second flow path 9 ... Generator 10 ... Reference rotating shaft 11 ... First Reference screw rotor 12 ... Second reference screw rotor 42 ... Rotating shaft (common rotating shaft) C ... Compression chamber E ... Expansion chamber P1 ... Expansion chamber inlet P2 ... Expansion chamber outlet Q1 ... Compression chamber inlet Q2 ... Compression chamber outlet

Claims (4)

A Brayton cycle engine having a plurality of screw rotors arranged in a casing,
A first reference screw rotor and a second reference screw rotor that rotate integrally;
A compression screw rotor in which the working medium is conveyed while being compressed by rotating in a state of meshing with the first reference screw rotor;
An expansion screw rotor in which the working medium is conveyed while being expanded by rotating in a state of meshing with the second reference screw rotor;
A regenerator having a first flow path through which the working medium compressed in the compression screw rotor flows toward the heater, and a second flow path through which the working medium expanded in the expansion screw rotor flows toward the cooler; With
A compression chamber in which the first reference screw rotor and the compression screw rotor are arranged and an expansion chamber in which the second reference screw rotor and the expansion screw rotor are arranged are formed in the casing. ,
The first reference screw rotor and the second reference screw rotor rotate integrally with a reference rotation shaft extending over both the compression chamber and the expansion chamber,
The heater is disposed on the expansion chamber side of the casing in a direction orthogonal to the extending direction of the reference rotation shaft as viewed from the casing.
The cooler is disposed on the compression chamber side of the casing in a direction orthogonal to the extending direction of the reference rotation shaft as viewed from the casing.
The regenerator is disposed in a direction orthogonal to the extending direction of the reference rotation shaft as viewed from the casing and in a direction different from the heater and the cooler, and the regenerator of the compression chamber and the expansion chamber of the casing Extending over both,
The Brayton cycle engine characterized in that the compressed working medium and the expanded working medium flow in opposite directions in the regenerator . Further comprising the connected generator to the rotating shaft or the rotating shaft of the first reference screw rotors of the compression screw rotor, the generator according to claim 1, characterized in Rukoto is cooled by the cooler Brayton cycle agency.   3. The Brayton cycle engine according to claim 1, wherein the rotation shaft of the compression screw rotor and the rotation shaft of the expansion screw rotor are arranged on the same axis.   The Brayton cycle engine according to claim 3, wherein the compression screw rotor and the expansion screw rotor have a common rotating shaft.

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