The present application claims the benefit of Korean Patent Application No. 10-2015-0112421, filed on Aug. 10, 2015, which is incorporated herein by reference in its entirety.
The present disclosure relates to a vane-rotor type Stirling engine and, particularly to an engine that converts thermal energy into kinetic energy.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Stirling engines refer to external combustion engines that convert thermal energy into kinetic energy by sealing a heating medium, such as hydrogen or helium, in an enclosed space, and compressing and expanding the heating medium at different temperatures.
Stirling engines have high thermal efficiency in theory of thermodynamics, and do not have an explosion stroke during combustion. Thus, these Stirling engines have lower vibration and noise, compared to conventional internal combustion engines. In addition, these Stirling engines have an advantage of utilizing all heat sources, such as wood fuel, factory waste heat, and solar heat, as well as petroleum, natural gas, and fossil fuel.
The principle of Stirling engines is known to be designed by Stirling, a British minister in 1816. However, the Stirling engines didn't come into the spotlight due to the rapid development of steam engines and internal combustion engines. In recent years, the Stirling engines have, however, received attention again since heat-resistant material and sealing techniques are newly developed and the importance of energy saving and alternative energy is emphasized.
As these Stirling engines, there are known an α-Stirling engine as illustrated in U.S. Pat. No. 7,171,811 (Feb. 6, 2007), a β-Stirling engine as described in U.S. Pat. No. 7,043,909 (May 16, 2006), etc. FIGS. 9 and 10 illustrate the shapes and driving methods of an α-Stirling engine and a β-Stirling engine, respectively. In the α-Stirling engine, a displacer is not provided therein, two respective pistons 1 and cylinders 2 are arranged to have a phase difference of 90°, and a heating medium 3 moves between a heat radiation cylinder and a heat absorption cylinder, as illustrated in
However, we have discovered that the piston reciprocates in reciprocating type Striling engines such as the α-Stirling engine and the β-Stirling engine, vibration and noise are generated during the operation thereof. In addition, the heating medium may be leaked from the contact portion between the piston and the cylinder, and complicated driving mechanisms, such as pistons, cylinders, connecting rods, and cranks, are required. For this reason, manufacturing costs are increased and it is difficult to minimize engines.
The present disclosure provides a Stirling engine capable of suppressing a loss of a heating medium due to vibration and friction, being manufactured at low cost, and having a small size.
The present disclosure can be understood by the following description, and become apparent with reference to the forms of the present disclosure.
In one form of the present disclosure, a Stirling engine includes a housing for storing a heating medium in an internal space, a rotor eccentrically disposed in the housing and having a plurality of vane slots, a plurality of vanes inserted into the vane slots, a heater for heating the heating medium in the housing, a radiator for cooling the heating medium in the housing, and an output shaft coupled to the rotor so as to output power to the outside.
In the Stirling engine, the internal space of the housing is configured of a heat absorption portion as a space in which the heating medium is heated, and a heat radiation portion as a space in which the heating medium is cooled. The plurality of vanes include heat absorption portion-side vanes configured such that one end of each of the heat absorption portion-side vanes is inserted into each of the vane slots, and the other end thereof comes into contact with an inner surface of the housing forming the heat absorption portion during rotation of the rotor, and heat radiation portion-side vanes configured such that one end of each of the heat radiation portion-side vanes is inserted into each of the vane slots, and the other end thereof comes into contact with the inner surface of the housing forming the heat radiation portion during rotation of the rotor.
In the Stirling engine, when the rotor rotates, the heating medium is expanded and heated in the heat absorption portion so as to be isothermally expanded, radiates heat under constant volume while moving from heat absorption portion to the heat radiation portion, is compressed and cooled in the heat radiation portion so as to be isothermally compressed, and absorbs heat under constant volume while moving from the heat radiation portion to the heat absorption portion, thereby allowing power to be generated for rotation of the output shaft.
In one form, the housing may include a heat absorption portion-side outer housing having a first hole forming the heat absorption portion, a heat radiation portion-side outer housing having a second hole forming the heat radiation portion, and outer housings for respectively covering the first and second holes from the outsides. The heat absorption portion-side outer housing may come into contact with the heat radiation portion-side outer housing such that the heat absorption portion directly communicates with the heat radiation portion. When the rotor rotates, the other ends of the heat absorption portion-side vanes may come into contact with a wall surface of the first hole, and the other ends of the heat radiation portion-side vanes may come into contact with a wall surface of the second hole.
In another form, shapes of first and second holes may be determined such that the rotor is eccentrically disposed in the heat absorption portion and the heat radiation portion.
In still another form, the heat absorption portion-side vanes and the heat radiation portion-side vanes may be inserted into the same vane slots formed in the rotor.
The heater may transfer heat to the heating medium through the outer housing for covering the heat absorption portion-side outer housing, and the radiator may radiate heat from the heating medium through the outer housing for covering the heat radiation portion-side outer housing.
In another form, the first and second holes may be arranged to have a predetermined phase angle difference.
In still another form, each of the heat absorption portion-side outer housing, the heat radiation portion-side outer housing, and the outer housings may have a plate shape, and the plate-shaped heat absorption portion-side outer housing and heat radiation portion-side outer housing may be stacked between the plate-shaped outer housings.
In other form, the rotor may be configured in such a manner that a heat absorption portion-side rotor, into which the heat absorption portion-side vanes are inserted, a heat radiation portion-side rotor into which the heat radiation portion-side vanes are inserted, and a shaft connecting the heat absorption portion-side rotor to the heat radiation portion-side rotor are formed integrally with one another. The heat absorption portion-side rotor may have a first groove formed therein such that one end of the first groove communicates with the heat absorption portion, the heat radiation portion-side rotor may have a second groove formed therein such that one end of the second groove communicates with the heat radiation portion, and the shaft may have a third groove communicating with the other ends of the first and second grooves. Accordingly, when the heating medium radiates heat under constant volume and absorbs heat under constant volume, the heating medium may move between the heat absorption portion and the heat radiation portion through a passage formed by the first, second, and third grooves.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
The configuration of the Stirling engine according to the form of the present disclosure will be described below with reference to
The Stirling engine includes a housing 10, a rotor 20 which is eccentrically disposed in the housing 10 and has a plurality of vane slots 21, a plurality of vanes 31 and 32 inserted into the vane slots 21, a heater 50 for heating a heating medium 70 in the housing 10, a radiator 60 for cooling the heating medium 70 in the housing, and an output shaft 40 coupled to the rotor 20 so as to output power to the outside.
In the Stirling engine having the above structure, the heating medium 70 stored in the enclosed space in the housing 10 undergoes isothermal expansion-constant volume heat radiation-isothermal compression-constant volume heat absorption processes by the continuous rotation of the rotor 20, which is eccentrically disposed in the housing 10, and thus power is generated so that the output shaft connected to the rotor is rotated. Through this process, the power may be generated without complicated components such as pistons, cylinders, and connecting rods.
That is, the outer housing 13, the heat absorption portion-side outer housing 11, the heat radiation portion-side outer housing 12, and the outer housing 14 are stacked in this order in the direction toward the radiator 60 from the heater 50, as illustrated in
As illustrated in
As illustrated in
As illustrated in
As illustrated in
In one form, an elastic body such as a spring or a positioning ring may be provided between the associated vane slot 21 and one end of each vane, such that the other ends of the heat absorption portion-side vanes 31 and the heat radiation portion-side vanes 32 may come into close contact with the wall surfaces of the first and second holes 11a and 12a during the rotation of the rotor 20.
Through the eccentric arrangement of the rotor 20 and the arrangement of the vanes, the heating medium 70 may be expanded and compressed in the respective heat absorption portion and heat radiation portion by the heat absorption portion-side vanes 31 and the heat radiation portion-side vanes 32 during the rotation of the rotor 20.
As illustrated in
To this end,
The outer housing 13 and 14 cover the respective first and second holes 11a and 12a, which are respectively formed in the heat absorption portion-side outer housing 11 and the heat radiation portion-side outer housing 12, from the outsides, thereby serving to seal the inside of the housing 10. In addition, the outer housing 13 and 14 serve together to transfer heat from the heater 50 to the heating medium 70 in the heat absorption portion and to discharge the heat of the heating medium 70 to the radiator 60.
The output shaft 40 illustrated in
As such, the heating medium continuously undergoes the isothermal expansion-constant volume heat radiation-isothermal compression-constant volume heat absorption processes so that power is generated, and thus the power may be transferred to the outside through the output shaft 40 which is coaxially connected to the rotor 20.
Meanwhile,
As seen from the comparison result in
In accordance with the Stirling engine illustrated in
In another form, the heat absorption portion-side rotor 24 and the heat radiation portion-side rotor 23 are cylindrical members which have respective insertion holes formed at the center portions thereof such that one side end portion of the shaft 22 may be inserted into the insertion holes. The heat absorption portion-side rotor 24 and the heat radiation portion-side rotor 23 have a plurality of vane slots formed in the circumferential direction thereof for insertion of the respective heat absorption portion-side vanes 31 and heat radiation portion-side vanes 32.
The shaft 22 axially extends between the heat absorption portion-side rotor 24 and the heat radiation portion-side rotor 23, and one end and the other end thereof are respectively inserted into the heat absorption portion-side rotor 24 and the heat radiation portion-side rotor 23. One end or the other end of the shaft 22 is connected to an output shaft, which is not illustrated in
The Stirling engine includes a heat absorption portion-side outer housing 11 and a heat radiation portion-side outer housing 12 which respectively cover the outer peripheries of the heat absorption portion-side rotor 24 and the heat radiation portion-side rotor 23. Accordingly, a heat absorption portion is formed between the outer peripheral surface of the heat absorption portion-side rotor 24 and the inner peripheral surface of the heat absorption portion-side outer housing 11, and a heat radiation portion is formed between the outer peripheral surface of the heat radiation portion-side rotor 23 and the inner peripheral surface of the heat radiation portion-side outer housing 12.
As illustrated in
In one form, the first groove 81 extends toward the outer peripheral surface of the heat absorption portion-side rotor 24 from the center portion thereof, and one end of the first groove 81 is opened toward the heat absorption portion. In another form, the second groove 82 extends toward the outer peripheral surface of the heat radiation portion-side rotor 23 from the center portion thereof, and one end of the second groove 82 is opened toward the heat radiation portion. In still another form, the third groove axially extends within the shaft 22, and communicates with the other ends of the first and second grooves 81 and 82. As illustrated in
In accordance with the form illustrated in
As illustrated in
In the Stirling engine according to the form illustrated in
In addition, in the constant volume heat absorption process illustrated in
Since a Stirling engine according to the present disclosure may not need the reciprocating motion of a piston for generation of power, it is advantageous in noise and vibration compared to a conventional Stirling engine. In addition, since a heating medium moves between a heat absorption portion and a heat radiation portion in the same enclosed space within a housing, there is no concern that the heating medium is leaked between a piston and a cylinder.
Since the Stirling engine according to the present disclosure may not need complicated configurations such as pistons, cylinders, and connecting rods, compared to the conventional Stirling engine, it has a simple structure. Thus, the Stirling engine can be compact and manufactured at low cost, compared to the conventional Stirling engine.
Since the Stirling engine according to the present disclosure may not need intake and exhaust valves, compared to the conventional Stirling engine, it has a simple structure, and it is possible to configure heat sources for heating the heat absorption portion in various manners.
While the present disclosure has been described with respect to the specific forms, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present disclosure as defined in the following claims.
Number | Date | Country | Kind |
---|---|---|---|
10-2015-0112421 | Aug 2015 | KR | national |
Number | Name | Date | Kind |
---|---|---|---|
7043909 | Steele | May 2006 | B1 |
7171811 | Berchowitz et al. | Feb 2007 | B1 |
7549289 | Herring | Jun 2009 | B2 |
9086013 | Franklin | Jul 2015 | B2 |
Number | Date | Country |
---|---|---|
2007-192443 | Aug 2007 | JP |
2013-60846 | Apr 2013 | JP |
10-0829957 | May 2008 | KR |
10-2012-0140468 | Dec 2012 | KR |
Entry |
---|
Machine translation of KR 20120140468 A, accessed on Jun. 20, 2017. |
Number | Date | Country | |
---|---|---|---|
20170045017 A1 | Feb 2017 | US |