JP2006200434A - Power generating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power generating device preventing noise and vibration at a time of drive, promoting miniaturization of the device, and improving durability and reliability of the device at a low cost. <P>SOLUTION: In the power generating device which is Rankine cycle provided with a heat source capable of evaporating working medium, an expansion machine expanding evaporated working medium, a condenser condensing working medium from the expansion machine, and a pump circulating working medium from the condenser to the heat source, and which has a generator connected to the expansion machine to output expansion work of the working medium as electric power, the expansion machines are connected to both ends of the drive shaft of the generator, each expansion machine and the generator are stored in independent chambers respectively, a first chamber storing one expansion machine to which working medium evaporated by the heat source is introduced and a second chamber storing another expansion machine expanding working medium expanded by one expansion machine further are communicated one another, the first chamber and a third chamber storing the generator are shut off and the second chamber and the third chamber are communicated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power generation device using a Rankine cycle, and more particularly to a power generation device in which a plurality of expanders are incorporated in a cycle.

  Conventionally, there is a circuit that circulates a fluid as a working medium, and has a pressurizing unit that pressurizes the fluid and a heating unit that heats, and the pressure / heated fluid is supplied and the output from the expansion work is taken out. Generator comprising a condenser, a condenser that condenses the fluid that has worked in the expander again, and a Rankine cycle that has a pump that sends the condensed fluid back to the pressurizing means, and a generator is connected to the expander of the Rankine cycle Is well known (for example, Patent Document 1).

Further, in order to achieve a reduction in parts and compactness of the power generation apparatus, a proposal (for example, Patent Document 2) in which the expander and the generator are connected to a common drive shaft, or the fluid expansion rate is increased to extract power. In order to improve efficiency, proposals have been made to arrange a plurality of expanders and generators on the same drive shaft and expand the fluid in stages in each expander (for example, Patent Documents 3, 4, 5, and 6).
Japanese Utility Model Publication No. 62-2241 JP-A-6-159015 JP 2003-106108 A JP-A-56-165701 JP-A-57-303 JP-A-57-304

  However, in the power generator as in Patent Document 3, since a plurality of expanders are connected to one side of the drive shaft of the generator, the stress from the expander is concentrated only on one side of the drive shaft, There is a risk of increased vibration and noise during driving. In addition, if a scroll type expander in which the working medium flows in from the center of the spiral body and the expanded working medium flows out from the side of the spiral body is connected in series, the piping path of the working medium becomes complicated. There is a risk that the entire apparatus becomes large. In addition, although the generator is heated more or less with power generation, the devices described in Patent Documents 4 to 6 are expanded in any one of the expanders, and the hot working medium is still on the generator side. Since it flows directly in, the generator is in a state where it is more easily heated. If the generator is overheated, the durability and reliability of the generator may be adversely affected.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a power generation device that can reduce the size and size of the device while preventing vibration and noise during driving, and can improve the durability and reliability of the device at low cost.

  In order to solve the above problems, a power generator according to the present invention includes a heat source capable of evaporating a working medium, an expander that expands the evaporated working medium, a condenser that condenses the working medium from the expander, and the condensation In the Rankine cycle comprising a pump for circulating the working medium from the vessel to the heat source, the generator is connected to the expander so that the expansion work of the working medium is output as electric power. An expander is connected to both ends of the drive shaft of the generator, and each expander and generator are housed in independent chambers, of which one expander into which the working medium evaporated by the heat source is introduced is housed. And the second chamber in which the other expander for further expanding the working medium expanded by the one expander is communicated with each other, and the first chamber and the generator are accommodated. With the third room Blocked, and consists of those characterized in that communication between the second and third chambers. In such a configuration, since the expanders are provided at both ends of the drive shaft of the generator, the stress accompanying the drive of the expander acts from both ends of the drive shaft. Therefore, it is possible to greatly reduce vibration and noise when the apparatus is driven while increasing the expansion rate of the working medium and improving the power extraction efficiency. In the above configuration, the high-temperature working medium expanded by the heat source first flows into the first chamber and is expanded to a predetermined expansion ratio by one of the expanders. Next, the working medium expanded by one expander flows into the second chamber and is expanded to a predetermined expansion ratio by the other expander. Further, the working medium expanded by the other expander is sent to the condenser through the third chamber in which the generator is accommodated. Therefore, the working medium is sufficiently expanded by one expander and the other expander and flows into the third chamber in a state of low temperature, so that the generator housed in the third chamber is effectively cooled. Thus, overheating of the generator can be surely prevented.

  Each of the expander and the generator is preferably housed in one housing. That is, if a third chamber is provided in the approximate center of one housing and the first chamber and the second chamber are arranged on both sides of the third chamber, the expander is connected to both ends of the drive shaft of the generator, The expander and the generator can be stored in independent chambers. Further, if the expander and the generator are housed in one housing, the apparatus can be reduced in size.

  In order to cool the generator efficiently, an inlet portion for the working medium from the second chamber is opened at the upper portion of the third chamber, and an outlet portion for leading the working medium to the outside is provided at the lower portion. Is preferred. In such a configuration, since the working medium flowing into the third chamber from the inlet portion passes through the third chamber without being exhausted and is led out to the outside from the outlet portion, the cooling efficiency of the generator can be improved. Moreover, if an exit part is provided in the bottom part of a 3rd chamber, even if it is a case where a working medium liquefies, it can lead out smoothly outside.

  The first chamber and the second chamber can be communicated, for example, via a communication path. The communication path can be provided in a housing in which each chamber is partitioned, but the communication path may be provided outside the housing.

  The method for shutting off the first chamber and the third chamber is not particularly limited, and a mechanical seal, a lip seal, or the like can be used.

  In the present invention, the working medium is expanded by one of the expanders, and further expanded by the other expander. For this reason, the circulating weight of the working medium supplied to both expanders is the same, but the gas density is different. Therefore, it is preferable that the volume of one expander housed in the first chamber is set smaller than the volume of the other expander housed in the second chamber. If comprised in this way, a working medium can be efficiently expanded, suppressing the pressure loss in the other expander.

  The one expander and the other expander are not particularly limited. For example, a scroll expander can be applied.

  According to the power generation device according to the present invention as described above, since the expander is connected to both ends of the drive shaft of the generator, the stress from the expander accompanying the drive of the device acts from both ends of the drive shaft. Therefore, vibration and noise during driving of the apparatus can be prevented. In addition, since the expander can be arranged more compactly than the conventional device, the overall size of the device can be reduced. Furthermore, since the generator is efficiently cooled, overheating of the generator can be prevented and the durability and reliability of the apparatus can be improved.

Hereinafter, preferred embodiments of a power generator according to the present invention will be described with reference to the drawings.
FIG. 1 shows a power generator according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a power generator. The power generation apparatus 1 includes a solar heat collector 2 as a heat source capable of evaporating a working medium (for example, refrigerant), expanders 3 and 4 that expand the working medium evaporated by the solar heat collector 2, A condenser 5 that condenses the working medium from the expanders 3 and 4 and a pump 6 that sends the working medium from the condenser 5 back to the solar heat collector 2 as a heat source are provided. And the circulation circuit 7 of the working medium provided with these apparatuses is comprised as a Rankine cycle.

  A control valve 10 is provided in the middle of the flow path of the working medium from the solar heat collector 2 to the expanders 3 and 4 so that the amount of fluid supplied to the expander 3 is controlled. .

  The expanders 3 and 4 are connected to both ends of the drive shaft 9 of the generator 8, and the expansion work of the working medium by the expander 3 and the expander 4 is output as electric power via the generator 8. ing. In this embodiment, as shown in FIG. 3, the expanders 3 and 4 are constituted by scroll type expanders. The expanders 3 and 4 and the generator 8 are accommodated in the housing 11. The housing 11 is divided into a first chamber 12 in which the expander 3 is accommodated, a second chamber 13 in which the expander 4 is accommodated, and a third chamber 14 in which the generator 8 is accommodated.

  As shown in FIG. 3, the second chamber 13 and the third chamber 14 are communicated with each other via a passage 15 as an inlet portion. A plurality of passages 15 are opened in the circumferential direction of the third chamber 14. Further, a passage 16 serving as a fluid outlet is opened at the bottom of the third chamber 14.

  On the other hand, the first chamber 12 and the third chamber 14 are blocked by a lip seal 17.

  The first chamber 12 and the second chamber 13 are communicated with each other via a communication path 18. The fluid expanded by the expander 3 accommodated in the first chamber 12 is further expanded by the expander 4 accommodated in the second chamber 13 via the communication path 18, and then is passed from the passage 15 to the third chamber 14. It flows into the inside and is further sent to the condenser 5 through the passage 16. In this embodiment, the communication path 18 that communicates the first chamber 12 and the second chamber 13 is provided in the housing 11, but may be provided outside the housing 11 as shown in FIG. .

  The expander 3 is composed of a scroll type expander in which a fixed scroll 19 and a movable scroll 20 are engaged with each other at an angle. A bottom plate 23 of the movable scroll 20 is connected to one end of the drive shaft 9 via an eccentric bush 24. A ball bearing 25 is provided on the outer edge of the bottom plate 23 of the movable scroll 20. The movable scroll 20 turns with the expansion of the fluid flowing in from the substantially center of the expander 3. Then, the working medium that has been gradually expanded flows out from the meshing end portions of the scrolls 19 and 20, and flows in from the approximate center of the expander 4 accommodated in the second chamber 13 through the communication path 18. It has become.

  The expander 4 is composed of a scroll type expander in which a fixed scroll 21 and a movable scroll 22 are meshed with each other at an angle. A bottom plate 26 of the movable scroll 22 is connected to the other end of the drive shaft 9 via an eccentric bush 27. A ball bearing 28 is provided on the outer edge of the bottom plate 26 of the movable scroll 22. The movable scroll 22 turns with the expansion of the fluid flowing in from the substantially center of the expander 4. Then, the gradually expanded working medium flows out from the meshing end portions of the scrolls 21 and 22 and flows into the third chamber 14 through the passage 15.

  In the present embodiment, the drive shaft 9 of the generator 8 rotates with the turning motion of the movable scrolls 20, 22, and the drive shaft 9 and the rotor 23 rotate together to generate power by the generator 8. Yes. In this embodiment, as shown in FIG. 3, the volume of the expander 4 is set larger than the volume of the expander 3. In the present embodiment, the fixed scrolls 19 and 21 of the expanders 3 and 4 are formed integrally with the housing 11.

  The generator 8 includes a rotor 23 that rotates integrally with the drive shaft 9, and a stator 24 provided around the rotor 23.

  In this embodiment, since the expanders 3 and 4 are provided at both ends of the drive shaft 9 of the generator 8, the stress accompanying the drive of the expanders 3 and 4 acts from both ends of the drive shaft 9. Therefore, it is possible to greatly reduce vibration and noise when the apparatus is driven while increasing the expansion rate of the working medium and improving the power extraction efficiency. The high-temperature working medium expanded by the solar heat collector 2 as a heat source first flows into the first chamber 12 and is expanded to a predetermined expansion ratio by the one expander 3. Next, the working medium expanded by one expander 3 flows into the second chamber 13 and is expanded to a predetermined expansion ratio by the other expander 4. Furthermore, the working medium expanded by the other expander 4 is sent to the condenser via the third chamber 14 in which the generator is accommodated. Accordingly, the working medium flows into the third chamber 14 in a state where the working medium is sufficiently expanded and cooled at the one expander 3 and the other expander 4, so that the power generation stored in the third chamber 14 is performed. The machine 8 is cooled effectively and the generator 8 can be reliably prevented from overheating.

  In the present embodiment, the third chamber 14 is provided in the approximate center of one housing 11, and the first chamber 12 and the second chamber 13 are disposed on both sides of the third chamber 14. The expanders 3 and 4 are connected to both ends of the drive shaft 9 of the machine 8, and the expanders 3 and 4 and the generator 8 can be stored in independent chambers. Therefore, the expanders 3 and 4 and the generator 8 can be accommodated in one housing 11, and the downsizing of the apparatus is promoted.

  Further, in the present embodiment, a passage 15 serving as an inlet portion for the working medium from the second chamber 13 is opened in the upper portion of the third chamber 14, and a passage 16 serving as an outlet portion for leading the working medium to the outside is provided in the lower portion. Is provided. Therefore, since the working medium that has flowed into the third chamber 14 from the passage 15 passes through the third chamber 14 and is led out to the outside from the passage 16, the cooling efficiency of the generator 8 can be improved. Further, since the passage 16 is provided in the lower portion of the third chamber 14, even if the working medium is liquefied, it can be smoothly led out.

  Furthermore, in this embodiment, the volume of the expander 4 is set larger than the volume of the expander 3. That is, the working medium is expanded by one expander 3 and then expanded by the other expander 4. For this reason, the circulating weight of the working medium supplied to both the expanders 3 and 4 is the same, but the gas density is different. Therefore, if the volume of one expander 3 accommodated in the first chamber 12 is set smaller than the volume of the other expander 4 accommodated in the second chamber 13, The working medium can be efficiently expanded while suppressing the pressure loss.

  The power generation apparatus according to the present invention can be applied to a system that generates power using various heat sources such as solar heat and geothermal heat, and any working medium can be used as long as it can form a Rankine cycle. is there.

It is a schematic equipment system diagram of the power generator concerning one embodiment of the present invention. It is a general | schematic apparatus system diagram of the electric power generating apparatus which concerns on another embodiment of this invention. It is an expanded sectional view of the housing part of the power generator of FIGS.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power generator 2 Solar collector 3, 4 Expander 5 Condenser 6 Pump 7 Circulation circuit 8 Generator 9 Drive shaft 10 Control valve 11 Housing 12 1st chamber 13 2nd chamber 14 3rd chamber 15, 16 Passage 17 Lip seal 18 Communication path 19, 21 Fixed scroll 20, 22 Movable scroll 23, 26 Bottom plate 24, 27 Eccentric bush 25, 28 Ball bearing

Claims (7)

  A heat source capable of evaporating the working medium; an expander that expands the evaporated working medium; a condenser that condenses the working medium from the expander; and a pump that circulates the working medium from the condenser to the heat source. In the Rankine cycle, the generator is connected to the expander so that the expansion work of the working medium is output as electric power. The expander is connected to both ends of the drive shaft of the generator, and each expansion The first chamber in which one expander into which the working medium evaporated by the heat source is introduced, and the operation expanded by the one expander are housed in separate chambers. The second chamber in which the other expander for further expanding the medium is communicated with each other, the first chamber and the third chamber in which the generator is accommodated are shut off, and the second chamber and the third chamber are separated. Specially connected to the room Power generation apparatus according to.   The power generator according to claim 1, wherein each of the inflator and the generator is housed in one housing.   The power generation device according to claim 1 or 2, wherein an outlet for leading the working medium to the outside is provided at the bottom of the third chamber.   The power generator according to any one of claims 1 to 3, wherein the first chamber and the second chamber communicate with each other through a communication path.   The power generator according to any one of claims 1 to 4, wherein the first chamber and the third chamber are blocked by a mechanical seal or a lip seal.   The power generation according to any one of claims 1 to 5, wherein the volume of one expander housed in the first chamber is set smaller than the volume of the other expander housed in the second chamber. apparatus. The power generator according to any one of claims 1 to 6, wherein the expander is a scroll expander.

Images