JP2005083343A - Power-generating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide a small-sized power-generating apparatus in which vibration and noise are controlled, and further durability and reliability are improved. <P>SOLUTION: In the power-generating apparatus, a Rankine cycle is constituted of a heat source capable of evaporating a working medium, an expansion devices for expanding the evaporated working-medium, a condenser for condensing the working medium from the expansion devices, and a pump for circulating the working medium from the condenser to the heat source. A generator is connected to the expansion devices to output the work of expansion of the working medium as electric power. In the apparatus, both ends of the drive-shaft of the generator are connected to the expansion devices. <P>COPYRIGHT: (C)2005,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 extracted. 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, a proposal has 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 Document 3).
Japanese Utility Model Publication No. 62-2241 JP-A-6-159015 JP 2003-106108 A (FIG. 1)

  However, in the power generator as shown in FIG. 1 of 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. However, there is a risk that vibration and noise during driving of the power generation device may increase. 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, the generator interior is heated more or less with power generation, but if the interior is excessively heated, the durability of the generator may be adversely affected. Moreover, in order to prevent the fluid from leaking from the expander, it is necessary to apply a large number of expensive mechanical seals, which may increase the cost.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a power generator that can reduce the size of the device while preventing vibration and noise during driving, and that 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. In such a power generator, 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.

  The generator and the expander are preferably housed in a single housing. In the power generator according to the present invention, the generator and the expander can be arranged more compactly than in the case where a plurality of generators are arranged in series on one side of the drive shaft of the generator. A generator and an expander can be easily accommodated in one housing.

  A control valve for controlling the inflow of the working medium to one or two or more expanders selected from a plurality of expanders is provided in the middle of the circuit of the working medium from the heat source to the expander. It is preferable. In this way, all of the expanders or one or more selected expanders can be operated. For example, when the heat source is solar heat, the amount of heat from the heat source decreases when the amount of solar radiation decreases in cloudy weather or in the morning and evening. In this case, it is necessary to operate the power generation device while reducing the circulation amount of the working medium in the circuit. That is, when the circulating amount of the working medium is not reduced, the expansion efficiency of each expander is remarkably lowered, so that power cannot be efficiently extracted. However, if the expander can be selectively operated as described above, power can be taken out with high efficiency.

  The insides of the plurality of expanders are preferably communicated with each other. In this way, the expansion rate can be freely set regardless of the type of the working medium, and the power extraction efficiency can be improved, so that the power generation efficiency of the generator can be improved. Moreover, it is preferable that the inside of any one of the plurality of expanders is in communication with the inside of the generator. If it does in this way, the inside of a generator can be cooled with a working medium, and overheating can be prevented. In particular, if the inside of the expander arranged at the most downstream in the flow direction of the working medium is communicated with the inside of the generator, the inside of the generator can be cooled with the working medium that has been expanded in stages and sufficiently cooled. . Further, since the mechanical seal between the expander and the generator disposed at the most downstream side is not necessary, the number of parts and the number of assembly steps can be reduced accordingly.

  The expander can be directly connected to the drive shaft of the generator, but can also be connected via a gear, a clutch, a coupling or the like. For example, if a plurality of expanders are of the same capacity when connected via gears, the working medium is expanded by the first stage expander and then sent to the second and subsequent expanders. The expansion rate in the second and subsequent stage expanders decreases, and the rotational speed decreases. Therefore, if the gear is interposed, the output shaft of the second stage is increased and the rotational speed can be increased. Moreover, if it connects via a clutch, one or several expander can be selectively or can drive all the expanders, Therefore The expansion coefficient of a working medium can be changed. Therefore, a wide variety of working media and generators can be used. In addition, if an excessive stress is applied to the expander or the like by interposing the coupling, the coupling is destroyed and the apparatus is prevented from being damaged, so that the durability of the apparatus can be improved.

  The heat source is not particularly limited, and various heat sources can be used. Waste heat from various machines and facilities, geothermal heat, solar heat, boilers, etc. (for example, oil boilers, gas boilers, electric boilers) can be used. For example, in a system using solar heat, solar heat can be efficiently collected by using a solar heat collector.

  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.

Hereinafter, preferred embodiments of a power generator according to the present invention will be described with reference to the drawings.
1 to 3 show a power generator according to a first 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, and a circuit 12 that reaches the expander 3 and a circuit 13 that reaches the expander 4. Both and / or one of them is opened.

  The expanders 3 and 4 are connected to both ends of the drive shaft 9 of the generator 8 so that the expansion work of the working medium by the expander 3 and / or the expander 4 is output as electric power via the generator 8. It has become. In this embodiment, as shown in FIG. 2, the expanders 3 and 4 are constituted by scroll type expanders having spiral bodies 14 and 15. The working medium that has flowed in from the center of the spiral bodies 14 and 15 is expanded as the pocket portion gradually expands from the center toward the outer peripheral portion, and flows out from the sides of the spiral bodies 14 and 15. It has become. The expanders 3 and 4 and the generator 8 are accommodated in the housing 11. Mechanical seals 16 and 17 are provided at the connecting portions of the expanders 3 and 4 and the generator 8 to prevent leakage of the working medium from the expanders 3 and 4 to the outside.

  In the power generation apparatus 1 as in this embodiment, the expanders 3 and 4 are provided at both ends of the drive shaft 9 of the generator 8, so that the stress accompanying the drive of the expander acts from both sides of the shaft 9. Therefore, vibration and noise during driving of the device 1 can be greatly reduced. Moreover, since the expanders 3 and 4 and the generator 8 can be arranged more compactly than in the conventional device in which a plurality of expanders are connected to one side of the shaft 9, the expanders 3 and 4 and the generator 8 can be made smaller. Therefore, the entire apparatus 1 can be downsized.

  FIG. 3 shows a power generator 18 according to the second embodiment of the present invention. In addition, the same number is attached | subjected to the member same as the said 1st embodiment, and the description is abbreviate | omitted. In the present embodiment, as shown in FIG. 4, a circuit 19 is provided between the expander 3 and the expander 4, and the expander 3 and the expander 4 communicate with each other. Moreover, the inside of the expander 4 and the inside of the generator 8 are mutually connected via the channel | path 20 through which a working medium distribute | circulates. For this reason, the working medium expanded in the expander 3 is further expanded in the expander 4 through the circuit 19 and then flows into the generator 8 from the passage 20 and is distributed to the condenser 5. It has become.

  Also in the power generator 18 as in this embodiment, since the expanders 3 and 4 are provided on both sides of the drive shaft 9 of the generator 8, the overall size of the apparatus can be reduced according to the operation of the first embodiment. can do. Moreover, since the expander 3 and the expander 4 are connected via the circuit 19, the expansion rate of the working medium can be freely set. Therefore, an efficient Rankine cycle can be constructed regardless of the type of the working medium, and the power generation efficiency can be improved.

  Further, in the present embodiment, the inside of the expander 4 and the inside of the generator 8 arranged on the most downstream side in the working medium flow direction are communicated with each other via the passage 20. For this reason, the inside of the generator 8 can be cooled by the working medium whose pressure has been reduced in the expanders 3 and 4 and the temperature has been reduced, so that the generator 8 is prevented from being overheated. Reliability can be improved. Further, in the configuration in which the inside of the expander 4 and the inside of the generator 8 are communicated, the mechanical seal 17 shown in FIG. 2 can be omitted. Accordingly, the number of parts and the number of assembling steps can be reduced as much as the mechanical seal 17 is omitted, so that the cost of the apparatus can be reduced.

  FIG. 5 shows a connecting structure of an expander and a generator of a power generator according to a third embodiment of the present invention. In addition, the same number is attached | subjected to the member same as the said 1st, 2nd embodiment, and the description is abbreviate | omitted. Also in this embodiment, the expanders 3 and 4 are connected to both sides of the drive shaft 9 of the generator 8, but the expander 4 is connected via a gear 21. The expander 3 and the expander 4 are communicated with each other via a circuit 22, and the working medium expanded by the expander 3 is sent to the expander 4 via the circuit 22. After being expanded, it is sent to the condenser 5.

  Also in this embodiment, downsizing of the apparatus can be achieved according to the operation of the first embodiment. Further, since the expander 4 is connected to the drive shaft 9 of the generator 8 via the gear 21, the expansion coefficient of the working medium in the expander 4 can be easily varied. Therefore, various working media can be expanded to an optimal expansion rate.

  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 the 1st embodiment of the present invention. It is a structural diagram which shows the connection structure of the expander and generator of the electric power generating apparatus of FIG. It is a general | schematic apparatus system diagram of the electric power generating apparatus which concerns on the 2nd embodiment of this invention. FIG. 4 is a structural diagram illustrating a connection structure between an expander and a generator of the power generation device of FIG. 3. It is structural drawing which shows the connection structure of the expander and generator of the electric power generating apparatus which concerns on the 3rd embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,18 Power generator 2 Solar collector 3, 4 Expander 5 Condenser 6 Pump 7 Rankine cycle 8 Generator 9 Drive shaft 10 Control valve 11 Housing 12, 13, 19, 22 Circuit 14, 15 Spiral wound body 16 , 17 Mechanical seal 20 Passage 21 Gear

Claims (10)

  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 to output the expansion work of the working medium as electric power, and the expander is connected to both ends of the drive shaft of the generator. A power generator.   The power generator according to claim 1, wherein the generator and the expander are housed in a single housing.   The power generation according to claim 1 or 2, wherein a circuit of the working medium from the heat source to the expander is provided with a control valve for controlling the flow of the working medium to the selected one or more expanders. apparatus.   The power generator according to any one of claims 1 to 3, wherein the insides of the plurality of expanders are in communication with each other, and the inside of any one of the expanders and the inside of the generator are in communication with each other. .   The power generation device according to claim 4, wherein any one of the expanders is an expander disposed at the most downstream side in the flow direction of the working medium.   The power generator according to claim 1, wherein the expander is connected to the drive shaft via a gear.   The power generator according to claim 1, wherein the expander is coupled to the drive shaft via a clutch.   The power generator according to claim 1, wherein the expander is coupled to the drive shaft via a coupling.   The power generator according to any one of claims 1 to 8, wherein the heat source includes a heat collector that collects exhaust heat, geothermal heat, solar heat, and the like.   The power generator according to any one of claims 1 to 9, wherein the expander is a scroll expander.

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