CN113804018A - Waste heat recovery system and composite screw fluid machine used for the same - Google Patents
Waste heat recovery system and composite screw fluid machine used for the same Download PDFInfo
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- CN113804018A CN113804018A CN202011356080.6A CN202011356080A CN113804018A CN 113804018 A CN113804018 A CN 113804018A CN 202011356080 A CN202011356080 A CN 202011356080A CN 113804018 A CN113804018 A CN 113804018A
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- 239000012530 fluid Substances 0.000 title claims abstract description 140
- 238000011084 recovery Methods 0.000 title claims abstract description 26
- 239000002918 waste heat Substances 0.000 title claims abstract description 24
- 239000002131 composite material Substances 0.000 title claims abstract description 23
- 230000008878 coupling Effects 0.000 claims abstract description 57
- 238000010168 coupling process Methods 0.000 claims abstract description 57
- 238000005859 coupling reaction Methods 0.000 claims abstract description 57
- 238000005057 refrigeration Methods 0.000 claims abstract description 55
- 230000006835 compression Effects 0.000 claims description 22
- 238000007906 compression Methods 0.000 claims description 22
- 230000007246 mechanism Effects 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 11
- 230000000149 penetrating effect Effects 0.000 claims description 6
- 150000001875 compounds Chemical class 0.000 claims 1
- 230000008014 freezing Effects 0.000 claims 1
- 238000007710 freezing Methods 0.000 claims 1
- 238000002360 preparation method Methods 0.000 claims 1
- 239000002826 coolant Substances 0.000 description 14
- 239000003507 refrigerant Substances 0.000 description 14
- 239000000498 cooling water Substances 0.000 description 8
- 230000002093 peripheral effect Effects 0.000 description 6
- 238000004891 communication Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000005611 electricity Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000010908 plant waste Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 238000005192 partition Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 238000004378 air conditioning Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
- F28D7/02—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being helically coiled
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D17/00—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces
- F25D17/02—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces for circulating liquids, e.g. brine
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Engine Equipment That Uses Special Cycles (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
Abstract
The present invention provides an expander that constitutes a part of a rankine cycle and a waste heat recovery system that constitutes a compressor that constitutes a part of a refrigeration cycle, which can be formed simply and at low cost by a pressure-canceling type screw fluid machine, and further provides a composite fluid machine used for the waste heat recovery system. The composite fluid machine is a compressor in which a first screw fluid machine (3A) constitutes an expander of a Rankine cycle, and a second screw fluid machine (3B) constitutes a refrigeration cycle with the same structure as the first screw fluid machine (3A). The first screw fluid machine (3A) and the second screw fluid machine (3B) are coupled back to back via a coupling housing (3C), and a coupling shaft (30A) of the first screw fluid machine (3A) and a coupling shaft (30B) of the second screw fluid machine (3B) are coupled and fixed in the coupling housing (3C) to constitute a composite fluid machine (3).
Description
Technical Field
The present invention relates to an exhaust heat recovery system that recovers low-temperature exhaust heat such as engine exhaust heat and plant exhaust heat and drives a refrigeration cycle using the recovered exhaust heat as a power source, and also relates to a hybrid screw fluid machine used in the exhaust heat recovery system.
Background
The exhaust heat recovery device disclosed in patent document 1 (japanese patent No. 6674796) includes an air flow path, a Rankine Cycle (Rankine Cycle) flow path, and a refrigeration Cycle flow path, the air flow path being a flow path from an inlet to an outlet, and includes: a first compressor for sucking air from the inlet, compressing the air, and discharging the compressed air to the outlet; a first heat exchanger for recovering heat from compressed air downstream of the first compressor; a second heat exchanger for recovering heat from the compressed air on the downstream side of the first heat exchanger, wherein the Rankine Cycle (Rankine Cycle) flow path is a circulation flow path and is provided with: the first heat exchanger for evaporating the cooling medium by heat exchange with the compressed air; an expander driven by the refrigerant evaporated in the first heat exchanger; a first condenser that condenses the cooling medium exhausted from the expander; a pump for supplying the refrigerant condensed by the first condenser to the first heat exchanger, wherein the refrigeration cycle flow path is a circulation flow path through which the same type of refrigerant as the refrigerant flowing through the rankine cycle flow path flows, and the pump is provided with: the second heat exchanger for evaporating the cooling medium by heat exchange with the compressed air; a second compressor that is rotationally driven by the rotational driving force obtained by the expander and compresses the refrigerant evaporated in the second heat exchanger; a second condenser for condensing the cooling medium discharged from the second compressor; and an expansion valve for expanding the cooling medium condensed by the second condenser.
Effects according to this structure are disclosed to be achieved as follows: the waste heat of the compressor in the air flow path can be effectively utilized by the first heat exchanger in the Rankine cycle flow path and the second heat exchanger in the refrigeration cycle flow path; the rotational driving force generated by the expander in the rankine cycle flow path can be used as the rotational driving force of the second compressor in the refrigeration cycle flow path, and the driving power of the second compressor can be reduced to save energy; in this case, the second compressor is directly rotationally driven without converting the rotational driving force generated by the expander into electricity or the like, and thus there is no energy loss or the like associated with the electrical conversion or the like.
The waste heat utilization device disclosed in patent document 2 (japanese patent application laid-open No. 2011-214484) utilizes waste heat of a drive source, and the composite fluid machine includes: a drive source; a rotating electrical machine functioning at least as a generator; an expander for applying a rotational force to a drive shaft of the rotary motor by using a rankine cycle cooling medium; a compressor that sucks and discharges a refrigerant for a refrigeration cycle; and a switching mechanism that switches between a connection state in which the drive shaft is connected to the rotary shaft of the compressor and a disconnection state in which the drive shaft is disconnected from the rotary shaft, wherein the composite fluid machine constitutes a part of each of the rankine cycle circuit and the refrigeration cycle circuit, a region in which the refrigerant for the rankine cycle is present and a region in which the refrigerant for the refrigeration cycle is present are separated, and a rotor of the rotary electric machine is located in the region in which the refrigerant for the refrigeration cycle is present in the composite fluid machine. The composite fluid machine provided in the waste heat utilization device includes an integral casing including a center casing, a front casing, and a rear casing, wherein the center casing is provided with an electric motor, the front casing is provided with a screw-type compressor, and the rear casing is provided with a screw-type expander.
The vehicle exhaust heat recovery system disclosed in patent document 3 (japanese patent application laid-open No. 2019-120164) includes: the rankine cycle system includes a rankine cycle circuit having a rankine cycle circuit in which the following components are arranged in this order: a heater for heating the working fluid by using waste heat of the engine; an expander that expands the working fluid passed through the heater to generate power; a rankine condenser for condensing the working fluid having passed through the expander; and a working fluid pump for sending the working fluid to the heater via the rankine condenser, wherein the engine cooling water system includes an engine cooling water circuit in which cooling water is circulated via the heater and an engine via the pump, and the refrigeration cycle includes a refrigeration cycle circuit in which the following components are arranged in this order: a compressor compressing a cooling medium; a heat exchanger for releasing heat from the refrigerant compressed by the compressor; a pressure reducing device for reducing pressure after exchanging heat with outside air by the heat exchanger; and an evaporator for heating the depressurized cooling medium, wherein the heat exchanger is a heat exchanger for exchanging heat between the cooling water flowing through the engine cooling water circuit and the cooling medium flowing through the cooling medium circulation circuit, and is disposed between the heater and the engine in the engine cooling water circuit.
[ patent document 1 ] Japanese patent No. 6674796
[ patent document 2 ] Japanese patent application laid-open No. 2011-214484
[ patent document 3 ] Japanese patent laid-open No. 2019-120164.
From patent documents 1 to 3, there are known techniques for providing a rankine cycle that obtains a driving force by using waste heat generated from an internal combustion engine such as an engine, plant waste heat, and the like, and a refrigeration cycle; the refrigeration cycle uses the driving force obtained by the rankine cycle for driving a compressor of the refrigeration cycle.
In patent document 1, since the expander and the compressor are fluidly connected in the casing, the second compressor can be rotationally driven by the rotational driving force obtained when the cooling medium is expanded by the expander, and therefore, there is an effect that the driving power of the second compressor can be reduced to save energy, and further, there is an effect that the second compressor is directly rotationally driven without converting the rotational driving force generated in the expander into electricity or the like, and therefore, there is no energy loss accompanying the electricity conversion or the like. In patent document 1, since both the expander and the second compressor are screw type, both the suction side and the discharge side of the expander and the second compressor become the central portion of the casing, and therefore, the discharge flow path must be formed in the casing, and thus a problem occurs in that the formation of the discharge flow path is difficult.
In the composite fluid machine disclosed in patent document 2, a motor generator is disposed in the center of a center housing, and functions as a motor that rotates a rotor by energization of a coil of a stator, and also functions as a generator that generates electric power by rotation of the rotor, a screw-type compressor is provided between a support block provided in a front portion of the center housing and a front housing, a side plate is fixedly provided in a rear portion of the center housing so as to face a partition wall, a pump chamber is defined between the partition wall and the side plate, and a screw-type expander is provided between the support block provided in the rear portion of the center housing and the rear housing. As described above, in the present invention, the compression chamber, the electromagnetic clutch, the motor generator, the gear pump, and the expander are arranged in order from the front housing to the rear housing in the entire housing, and the structure is long in the axial direction, which has a disadvantage that the structure itself is complicated.
The vehicle exhaust heat recovery system described in patent document 3 includes a rankine cycle system, an engine cooling water system, and a refrigeration cycle system, but an expander constituting a part of the rankine cycle and a compressor constituting a part of the refrigeration cycle are configured as separate devices.
As described above, the waste heat recovery system is known to be constituted by the rankine cycle and the refrigeration cycle, and further, the following has been known: an expander constituting a part of the rankine cycle and a compressor constituting a part of the refrigeration cycle are integrally configured, and the expander and the compressor are configured by a screw fluid machine.
However, the spiral fluid portion serving as the expander and the spiral fluid portion serving as the compressor are provided in the same casing, which complicates the structure. In the above-described exhaust heat recovery system, it is difficult to easily form a composite fluid machine in which a screw-type expander and a compressor are integrally configured without a cost.
Further, in the screw fluid machine, since the compression space expands from the center toward the outer peripheral direction to become the expander and the compression space contracts from the outer peripheral direction toward the center to become the compressor, the normal screw fluid machine can be made to be either the expander or the compressor by changing the rotation direction of the drive shaft in a certain sense. However, in the conventional rotary screw compressor, in order to reduce an axial gas force (a pulling force) that tends to pull the two screws apart from each other in the main shaft direction due to the compression action of the fixed screw and the rotary screw, a pressure intermediate between the discharge pressure and the suction pressure is introduced into the rear surface of the rotary screw, and a pulling force that cancels the pulling force is generated. However, since the intermediate pressure is a value proportional to the suction pressure, when the rotation speed is different and the pressure is different, the back pressure becomes excessive or insufficient, the thrust between the rotating screw and the fixed screw changes, the mechanical efficiency decreases when the sliding friction between the tooth tips and the tooth bottoms of the respective land portions increases, and the performance may deteriorate when the clearance is excessively large. Further, since the compressor needs to include a check valve, an inlet, a release hole, and the like in the discharge portion, it is difficult to easily convert the same compressor to an expander, and actually, it is realistic to design the expander and the compressor exclusively.
Disclosure of Invention
In contrast, the pressure-canceling screw fluid machine has the following advantages: since no pulling-off force is generated in the axial direction, no pressure balance adjustment is required anyway. Therefore, the inventors of the present invention have found that, when a composite fluid machine is configured in which an expander constituting a part of a rankine cycle and a compressor constituting a part of a refrigeration cycle are integrated, by using a pressure-canceling screw fluid machine, the expander and the compressor can be used in combination by the same body. Thus, the present invention provides a simple and low-cost exhaust heat recovery system in which a pair of pressure-canceling screw fluid machines are coupled back to form a composite fluid machine, and one of the expanders disposed in the composite fluid machine drives the other compressor.
Accordingly, the present invention is a waste heat recovery system, comprising a rankine cycle and a refrigeration cycle, the rankine cycle comprising: a rankine evaporator that exchanges heat with the first heat exchange medium moving from the heat source and evaporates the second heat exchange medium; an expander that expands the second heat exchange medium evaporated by the rankine evaporator; a rankine condenser for condensing the second heat exchange medium expanded by the expander; and a pump for supplying the second heat exchange medium condensed by the rankine condenser to the rankine evaporator, wherein the refrigeration cycle includes: a condenser for a refrigeration cycle for condensing the third heat exchange medium; an expansion mechanism for adiabatically expanding the third heat exchange medium condensed by the condenser for a refrigeration cycle; an evaporator for a refrigeration cycle that evaporates the third heat exchange medium expanded by the expansion mechanism; and a compressor that compresses a third heat exchange medium evaporated by the refrigeration cycle evaporator, wherein the expander is a pressure-canceling first screw fluid machine, the compressor is a pressure-canceling second screw fluid machine having a structure similar to that of the first screw fluid machine, the first screw fluid machine and the second screw fluid machine are coupled back to back via a coupling housing, and a coupling shaft of the first screw fluid machine and a coupling shaft of the second screw fluid machine are coupled and fixed in the coupling housing to form a composite fluid machine.
With the above configuration, the second heat exchange medium evaporated by heat exchange with the first heat exchange medium supplied from the heat source in the rankine evaporator is thermally expanded when passing through the expander, and the coupling shaft is rotated by the expansion energy. Since the rotational force rotates the coupling shaft of the compressor, the third heat exchange medium circulating in the refrigeration cycle is compressed, and the third heat exchange medium circulates in the refrigeration cycle. In this way, low-temperature waste heat such as engine waste heat or plant waste heat is recovered as a heat source, and can be used as a drive source for driving the refrigeration cycle.
In the rankine cycle of the waste heat recovery system, a heating mechanism is preferably provided between the rankine evaporator and the expander. Therefore, in a refrigeration truck or the like, when the refrigerator is operated by the waste heat of the cooling water of the engine, the expander cannot be driven and the refrigerator must be stopped when the operation is stopped for a long time such as a night break, or when the heat source supply is stopped due to an unexpected trouble and the heating of the second heat exchange medium by the rankine evaporator is insufficient or stopped. In a refrigeration truck, it is fatal to stop a refrigerator, and some alternative operation mechanism is required, but since the refrigerator is originally configured without a motor, a complicated configuration in which an auxiliary motor can be used when the refrigerator is stopped is required as a solution. However, in the present invention, the insufficient heating can be compensated for only by providing the heating mechanism, and therefore, the driving force in the expander can be ensured with a simple configuration. As the heating means, a configuration using an external power source (for example, a battery, a solar power generator, a fuel cell, a commercial power source, or the like) is desired. In addition, the present invention is only concerned, and the structures of the compressor and the expander need not be particularly limited.
Further, the present invention provides a hybrid fluid machine used in the exhaust heat recovery system having the above-described configuration, including a first screw fluid machine and a second screw fluid machine having a configuration similar to that of the first screw fluid machine, the first screw fluid machine including: a housing including a substantially cylindrical side surface portion, a front end surface portion located on one side of the side surface portion, and a rear end surface portion located on the other side of the side surface portion, the housing defining an internal space and having an opening portion for communicating the internal space with the outside; a rotating shaft rotatably supported by the distal end surface portion; a connecting shaft rotatably supported by the rear end surface portion; a first driving screw member fixed to the rotary shaft and extending spirally in a radial direction; a second driving screw member fixed to the connecting shaft and extending spirally in a radial direction; a driving screw member including a first spiral driven screw engaged with the first driving screw of the first driving screw member to define a first compression space and a second spiral driven screw engaged with the second driving screw of the second screw member to define a second compression space, the driving screw member being rotatably held by the front end surface portion and the rear end surface portion; the first and second compression spaces are configured to gradually expand in space from the center toward the outer circumferential direction, a through hole penetrating the rotary shaft and provided in the rotary shaft communicates with the innermost peripheral ends of the first and second compression spaces, and the outermost peripheral ends of the first and second compression spaces communicate with the internal space; the second screw fluid machine is configured such that a connection shaft of the second screw fluid machine is connected to a connection shaft of the first screw fluid machine in the connection housing. According to the above-described pressure-canceling screw fluid machine, the same compressor and expander can be easily used in combination without generating an axial gas force (separating force) that tends to separate both screws from each other in the main axial direction in the related art.
Further, the first screw fluid machine is used as an expander constituting a part of the rankine cycle, and the second screw fluid machine is used as a compressor constituting a part of the refrigeration cycle.
With the above configuration, two screw fluid machines having the same structure are arranged back to back via a coupling housing, and the coupling shaft of the first screw fluid machine and the coupling shaft of the second screw fluid machine are coupled to each other in the coupling housing to constitute a composite screw fluid machine. Thus, a composite screw fluid machine including an expander and a compressor connected by two screw fluid machines having the same structure can be configured, and thus cost reduction is possible.
Further, it is preferable that the coupling housing defines a coupling space for accommodating a coupling portion between the coupling shaft of the first screw fluid machine and the coupling shaft of the second screw fluid machine, and the coupling space communicates with an internal space of the second screw fluid machine.
This makes it possible to seal the connection space in the connection housing from the outside air, thereby preventing the cooling medium from leaking into the atmosphere. Further, since the pressure is the same as the pressure in the internal space of the second screw fluid machine serving as the compressor, the shaft seal with the compressor can be eliminated. Further, since the pressure in both the expander casing and the coupling casing is low, the differential pressure is small, and the sealing by a simple shaft seal such as a lip seal is easy.
As described above, according to the present invention, the same body is used and coupled in the opposite direction to reverse the rotation direction, thereby enabling the use of the same body as the compressor and the expander, and thus cost reduction is possible.
Drawings
Fig. 1 is a schematic configuration diagram of an exhaust heat recovery system according to an embodiment of the present invention.
Fig. 2 is a schematic configuration diagram of an exhaust heat recovery system according to another embodiment of the present invention.
Fig. 3 is a schematic configuration diagram of a composite screw fluid machine.
Detailed Description
Embodiments of the present invention are described below with reference to the drawings.
[ example 1 ]
As shown in fig. 1, for example, an exhaust heat recovery system 1 according to an embodiment of the present invention includes a rankine cycle 6, and the rankine cycle 6 includes: a rankine evaporator 2 that absorbs heat of a first heat exchange medium (for example, water) moving from a heat source such as an engine waste heat source (a radiator or the like) or a plant waste heat source (steam or the like after power generation), and evaporates (gasifies) a second heat exchange medium (for example, a cooling medium such as HF01233zd or HFC245 fa); a first spiral fluid machine 3A as an expander for expanding the second heat exchange medium evaporated by the rankine evaporator 2; a rankine condenser 4 that condenses (liquefies) the heat of the second heat exchange medium expanded by the first screw fluid machine 3A by radiating the heat to, for example, passing air; and a pump 5 for supplying the second heat exchange medium condensed by the rankine condenser 4 to the rankine evaporator 2. Preferably, the rankine cycle is an Organic Rankine Cycle (ORC).
The exhaust heat recovery system 1 further includes a refrigeration cycle 10, and the refrigeration cycle 10 includes: a refrigeration cycle condenser 7 that radiates heat of a third heat exchange medium (e.g., a cooling medium such as R448A) to passing air and condenses the heat; an expansion mechanism 8 such as an expansion valve that adiabatically expands the third heat exchange medium condensed by the condenser 7 for a refrigeration cycle; an evaporator 9 for a refrigeration cycle, which absorbs heat of the passing air and evaporates the heat-exchange third medium expanded by the expansion mechanism 8; and a second screw fluid machine 3B as a compressor for compressing the third heat exchange medium evaporated by the evaporator 9 for a refrigeration cycle.
Further, the first screw fluid machine 3A and the second screw fluid machine 3B are coupled back to back via a coupling housing 3C, and the coupling shaft 30A of the first screw fluid machine 3A and the coupling shaft 30B of the second screw fluid machine 3B are coupled and fixed by a coupler or the like in the coupling housing 3C to constitute the composite fluid machine 3.
With the above configuration, the first heat exchange medium that carries waste heat from the engine or the like and the second heat exchange medium that circulates through the rankine cycle 6 exchange heat in the rankine evaporator 2, and the second heat exchange medium is evaporated (gasified) by the heat of the first heat exchange medium. The evaporated heat exchange medium passes through the first screw fluid machine 3A while expanding, and rotates the coupling shaft 30A of the expander 3A. Since the rotational force rotates the coupling shaft 30B of the second screw fluid machine 3B, the third heat exchange medium circulating in the refrigeration cycle 10 is condensed (liquefied) in the refrigeration cycle condenser 7, and the refrigerant heated and evaporated in the evaporator 9 is sucked into the second screw fluid machine 3B and compressed and discharged.
As described above, in the composite fluid machine 3 configured by arranging the screw fluid machines serving as the same body back to back via the coupling housings 3C and coupling the respective coupling shafts 30A, 30B, when the coupling shafts 30A, 30B are rotated in the same direction, one operates as a compressor and the other operates as an expander. This allows the refrigeration cycle 10 to be operated by the heat recovered by the rankine evaporator 2.
In the refrigeration cycle 10, the refrigeration-cycle evaporator 9 is disposed in an air flow path of an air conditioning system, for example, and absorbs heat of passing air to evaporate a third heat exchange medium, thereby cooling the passing air. This enables the refrigeration cycle to be driven by recovering heat from the engine radiator and the like.
[ example 2 ]
The exhaust heat recovery cycle 6A shown in fig. 2 is characterized in that a heating mechanism 11 such as a heater is provided between the rankine evaporator 2 and the first screw fluid machine 3A. Thus, when the second heat exchange medium passing through the rankine evaporator 2 is not sufficiently evaporated due to the stop or shortage of the heat source, the second heat exchange medium can be heated and sufficiently evaporated by the heating mechanism 11, and can be sufficiently expanded in the first spiral fluid machine 3A.
[ example 3 ]
As shown in fig. 3, for example, the hybrid fluid machine 3 used in the exhaust heat recovery system 1 includes a pressure-canceling first screw fluid machine 3A serving as an expander and a second screw fluid machine 3B serving as a compressor and having the same structure as the first screw fluid machine 3A.
The first screw fluid machine 3A that operates as an expander in example 3 includes: a case 36A including a substantially cylindrical side surface portion 31A, a front end surface portion 32A located on one side of the side surface portion 31A, and a rear end surface portion 33A located on the other side of the side surface portion 31A, and defining an internal space 34A and having an opening 35A for communicating the internal space 34A with the outside; a rotating shaft 37A rotatably supported by the distal end surface portion 32A; a connecting shaft 30A rotatably supported by the rear end surface portion 33A; a first driving screw member 38A fixed to the rotary shaft 37A and extending spirally in a radial direction; a second driving screw member 39A fixed to the connecting shaft 30A and extending spirally in the radial direction; the driven screw member 46A includes a spiral first driven screw 44A engaged with the first driving screw 40A of the first driving screw member 38A to define a first expansion space 42A and a spiral second driven screw 45 engaged with the second driving screw 41A of the second driving screw member 39A to define a second expansion space 43A, and is rotatably held by the front end surface portion 32A and the rear end surface portion 33A, the first and second compression spaces 42A and 43A are configured to gradually expand their spaces from the center toward the outer circumferential direction, a through hole 47A penetrating the rotation shaft 37A communicates with the innermost circumferential ends of the first and second expansion spaces 42A and 43A, and the outermost circumferential ends of the first and second expansion spaces 42A and 43A communicate with the internal space 34A. The refrigerant heated under high pressure flows into the central portion of the expander through the through hole 47, and is rotationally driven to generate power while expanding the capacity. Since the pressure inside the expander serves as a pressure canceling mechanism, no axial pulling force is generated, and pressure balance adjustment is not required, so that the expander and the compressor can be used as the same body.
The second screw fluid machine 3B that operates as a compressor in example 3 has the same structure as the first screw member 3A, and includes: a case 36B including a substantially cylindrical side surface portion 31B, a front end surface portion 32B located on one side of the side surface portion 31B, and a rear end surface portion 33B located on the other side of the side surface portion 31B, and having an opening 35B for partitioning an internal space 34B and communicating the internal space 34B with the outside; a rotating shaft 37B rotatably supported by the distal end surface portion 32B; a connecting shaft 30B rotatably supported by the rear end surface portion 33B; a first driving screw member 38B fixed to the rotary shaft 37B and extending spirally in the radial direction; a second driving screw member 39B fixed to the connecting shaft 30B and extending spirally in the radial direction; a driven screw member 46B including a spiral first driven screw 44B meshing with the first drive screw 40B of the first drive screw member 38B to define a first compression space (same as the first expansion space) 42B and a spiral second driven screw 45B meshing with the second drive screw 41B of the second drive screw member 39B to define a second compression space (same as the second compression space) 43B, and rotatably held by the front end surface portion 32B and the rear end surface portion 33B; the first and second compression spaces 42B, 43B are configured to gradually expand in space from the center toward the outer circumferential direction, a through hole 47B penetrating the rotary shaft 37B and provided in the rotary shaft 37B communicates with the innermost circumferential ends of the first and second compression spaces 42B, 43B, and the outermost circumferential ends of the first and second compression spaces 42B, 43B communicate with the internal space 34B. The low-temperature gaseous refrigerant is sucked through the through hole 35B, and the high-temperature and high-pressure refrigerant gas is discharged from the discharge port 47B while the volumes of the compression spaces 42B and 43B are reduced toward the center in the compressor 3B. Since the pressure generated inside the compressor 3B serves as a pressure canceling mechanism, no axial pulling force is generated, and no pressure balance adjustment is required, so that the expander and the compressor can be used in combination as the same body.
As described above, the second screw fluid machine 3B having the same configuration as the first screw fluid machine 3A is disposed back to back with respect to the first screw fluid machine 3A via the coupling casing 3C, and the coupling shaft 30A of the first screw fluid machine 3A and the coupling shaft 30B of the second screw fluid machine 3B are coupled and fixed in the coupling casing 3C. The rotary shaft 37A of the first screw fluid machine 3A and the rotary shaft 37B of the second screw fluid machine 3B are rotatably held by the distal end surface portions 32A, 32B via bearings or the like, respectively, and the distal ends thereof are sealed by caps 49A, 49B.
As described above, in embodiment 3, one of the complex fluid machines 3, for example, the first screw fluid machine 3A is used as an expander constituting a part of the rankine cycle 6 (or 6A), and the other of the complex fluid machines 3, for example, the second screw fluid machine 3B is used as a compressor constituting a part of the refrigeration cycle 10.
Further, the coupling case 3C defines a coupling space 3D that accommodates a coupling portion between the coupling shaft 30A of the first screw fluid machine 3A and the coupling shaft 30B of the second screw fluid machine 3B, and the coupling space 3D communicates with the internal space 34B of the second screw fluid machine 3B. In order to realize this structure, communication holes 48A, 48B penetrating the rear end surface portions 33A, 33B of the first and second screw fluid machines 3A, 3B are formed in the rear end surface portions 33A, 33B. In example 3, since the second screw fluid machine 3B functions as a compressor, the communication hole 48B formed in the rear end surface portion 33B of the second screw fluid machine 33B is opened, and the communication hole 48A formed in the rear end surface portion 33A of the first screw fluid machine 33A is closed. Accordingly, the internal space 34B of the second screw fluid machine 3B and the connection space 3D in the connection housing 3C are in a communication state and have the same pressure, and therefore, a shaft seal for connecting the peripheral edge of the shaft 30B is not necessary. In order to avoid mixing of different types of cooling media, it is preferable to provide a cap 50A constituting a lip seal to block the internal space 34A of the first screw fluid machine 3A serving as the expander and the connection space 3D. Further, since both the aforementioned internal space 34A and the joint space 3D are low pressure, the pressure difference applied to the lip seal becomes smaller, and the sealing becomes easy.
Further, in this embodiment 3, the opening portion 35A of the first screw fluid machine 3A communicating with the outside is opened at the front end surface portion 32A, and the opening portion 35B' of the front end surface portion 33B of the second screw fluid machine 3B is closed. Similarly, the opening 35B of the second screw fluid machine 3B communicating with the outside is opened in the side surface portion 31B, and the opening 35A' of the first screw fluid machine 3A is closed.
With the above configuration, in the rankine evaporator 2, the second heat exchange medium evaporated by heat exchange with the first heat exchange medium supplied from the heat source such as engine waste heat flows into the through hole 47A penetrating the rotation shaft 37A through the cap 49A, and moves in the outermost peripheral direction while expanding in the first and second expansion spaces 42A and 43A from the central portion of the first and second expansion spaces 42A and 43A, thereby rotating the rotation shaft 37A and the coupling shaft 30A. Thereby, the second screw fluid machine 3B can be operated via the coupling shaft 30B coupled to the coupling shaft 30A of the first screw fluid machine 3A.
As described above, according to the present invention, the refrigeration cycle can be operated by using waste heat of the engine or the like.
Reference numerals
1 waste heat recovery system
Evaporator for 2 rankine cycle
3 composite fluid machine
3A first screw fluid machine
3B second screw fluid machine
4 rankine condenser
5 Pump
6 rankine cycle
7 condenser for refrigeration cycle
8 expansion mechanism
9 evaporator for refrigeration cycle
10 refrigeration cycle
11 heating means.
Claims (5)
1. A waste heat recovery system includes a Rankine cycle and a refrigeration cycle,
the rankine cycle includes: a rankine evaporator that exchanges heat with a first heat exchange medium moving from a heat source and evaporates a second heat exchange medium; an expander that expands the second heat exchange medium evaporated by the rankine evaporator; a rankine condenser for condensing the second heat exchange medium expanded by the expander; and a pump for supplying the second heat exchange medium condensed by the Rankine condenser to the Rankine evaporator,
the freezing cycle includes: a condenser for a refrigeration cycle for condensing the third heat exchange medium; an expansion mechanism for adiabatically expanding the third heat exchange medium condensed by the condenser for a refrigeration cycle; an evaporator for a refrigeration cycle that evaporates the third heat exchange medium expanded by the expansion mechanism; and a compressor for compressing the third heat exchange medium evaporated by the evaporator for a refrigeration cycle,
it is characterized in that the preparation method is characterized in that,
the expander is a pressure-canceling first screw fluid machine, the compressor is a second screw fluid machine having a structure similar to that of the first screw fluid machine, the first screw fluid machine and the second screw fluid machine are coupled back to back via a coupling housing, and a coupling shaft of the first screw fluid machine and a coupling shaft of the second screw fluid machine are coupled and fixed in the coupling housing to constitute a composite fluid machine.
2. The waste heat recovery system according to claim 1, wherein a heating mechanism is provided between the rankine evaporator and the expander in the rankine cycle of the waste heat recovery system.
3. The composite fluid machine used in the exhaust heat recovery system according to claim 1 or 2, characterized by comprising a first screw fluid machine of a pressure-canceling type and a second screw fluid machine having the same structure as the first screw fluid machine,
the first screw fluid machine includes: a housing which is composed of a substantially cylindrical side surface portion, a front end surface portion located on one side of the side surface portion, and a rear end surface portion located on the other side of the side surface portion, and which defines an internal space and is provided with an opening portion for communicating the internal space with the outside; a rotating shaft rotatably supported by the distal end surface portion; a connecting shaft rotatably supported by the rear end surface portion; a first driving screw member fixed to the rotary shaft and extending spirally in a radial direction; a second driving screw member fixed to the connecting shaft and extending spirally in a radial direction; a driven screw member including a spiral first driven screw engaged with the first driving screw of the first driving screw member to define a first compression space and a spiral second driven screw engaged with the second driving screw of the second driving screw member to define a second compression space, the driven screw member being rotatably held by the front end surface portion and the rear end surface portion; the first and second compression spaces are configured to gradually expand in space from the center toward the outer circumferential direction, a through hole penetrating the rotary shaft and communicating with the innermost circumferential ends of the first and second compression spaces, the outermost circumferential ends of the first and second compression spaces communicating with the internal space,
the second screw fluid machine is disposed back to back with the first screw fluid machine via a coupling housing in which a coupling shaft of the first screw fluid machine and a coupling shaft of the second screw fluid machine are coupled and fixed.
4. The compound fluid machine according to claim 3, wherein said first screw fluid machine is used as a compressor constituting a part of a refrigeration cycle, and said second screw fluid machine is used as an expander constituting a part of a rankine cycle.
5. The hybrid fluid machine according to claim 3 or 4, wherein the coupling housing defines a coupling space that accommodates a coupling portion between the coupling shaft of the first screw fluid machine and the coupling shaft of the second screw fluid machine, and the coupling space communicates with an internal space of the first screw fluid machine.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020101482A JP7096961B2 (en) | 2020-06-11 | 2020-06-11 | Waste heat recovery system and compound scroll fluid machine used for it |
| JP2020-101482 | 2020-06-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113804018A true CN113804018A (en) | 2021-12-17 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011356080.6A Pending CN113804018A (en) | 2020-06-11 | 2020-11-27 | Waste heat recovery system and composite screw fluid machine used for the same |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP7096961B2 (en) |
| CN (1) | CN113804018A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50145935U (en) * | 1974-05-22 | 1975-12-03 | ||
| JPS5561273U (en) * | 1978-10-20 | 1980-04-25 | ||
| JPH0886205A (en) * | 1994-09-16 | 1996-04-02 | Toshiba Corp | Rotating machine |
| JP2000088380A (en) * | 1998-09-16 | 2000-03-31 | Sanyo Electric Co Ltd | Air cycle type chiller and scroll hydraulic machine |
| CN102706022A (en) * | 2010-10-13 | 2012-10-03 | 株式会社神户制钢所 | Refrigerator |
| JP2017155731A (en) * | 2016-03-04 | 2017-09-07 | 株式会社神戸製鋼所 | Exhaust heat recovery system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0737857B2 (en) * | 1989-07-28 | 1995-04-26 | ダイキン工業株式会社 | Scroll type fluid device and air conditioner |
| JP6854043B2 (en) | 2017-01-27 | 2021-04-07 | 三菱重工業株式会社 | Double rotation scroll type compressor and its assembly method |
-
2020
- 2020-06-11 JP JP2020101482A patent/JP7096961B2/en active Active
- 2020-11-27 CN CN202011356080.6A patent/CN113804018A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50145935U (en) * | 1974-05-22 | 1975-12-03 | ||
| JPS5561273U (en) * | 1978-10-20 | 1980-04-25 | ||
| JPH0886205A (en) * | 1994-09-16 | 1996-04-02 | Toshiba Corp | Rotating machine |
| JP2000088380A (en) * | 1998-09-16 | 2000-03-31 | Sanyo Electric Co Ltd | Air cycle type chiller and scroll hydraulic machine |
| CN102706022A (en) * | 2010-10-13 | 2012-10-03 | 株式会社神户制钢所 | Refrigerator |
| JP2017155731A (en) * | 2016-03-04 | 2017-09-07 | 株式会社神戸製鋼所 | Exhaust heat recovery system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP7096961B2 (en) | 2022-07-07 |
| JP2021195888A (en) | 2021-12-27 |
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