JP2009062909A - Stirling engine and stirling engine mounting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Stirling engine, capable of fixing a displacer ring with a simple structure and a Stirling engine mounting apparatus having the Stirling engine. <P>SOLUTION: A Stirling refrigerator 100 has a casing 110 having a back pressure space 170 and an operation space 150 including a compression space 151 and an expansion space 152 and sealed with a working medium, a piston 130 arranged between the back pressure space 170 and the operation space 150 and applying a pressure variation to the working medium in the operation space 150, a displacer 140 arranged between the compression space 151 and the expansion space 152 and operating by the pressure variation by the piston 130, and the displacer ring 192 arranged in the operation space 150 and energizing the displacer 140 toward a predetermined position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a Stirling engine and a Stirling engine mounted device, and more particularly to a Stirling engine having a piston and a displacer and a Stirling engine mounted device including the Stirling engine.

Examples of conventional Stirling engines having a piston and a displacer include those described in Japanese Patent Application Laid-Open No. 2002-89985 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2004-68713 (Patent Document 2).
JP 2002-89985 A JP 2004-68713 A

  In each of the Stirling engines described in Patent Documents 1 and 2, a displacer spring for applying an elastic force to the displacer is provided in a back pressure space located on the opposite side of the displacer with respect to the piston. For this reason, in the Stirling engines described in Patent Documents 1 and 2, it is necessary to penetrate the displacer rod protruding from the axial end surface of the displacer into the center hole of the piston, and high precision of the parts is required, and the number of parts Will increase. As a result, the manufacturing cost of the Stirling engine increases.

  The present invention has been made in view of the above problems, and an object of the present invention is a Stirling engine capable of fixing a displacer spring with a simple structure, and a Stirling engine-equipped device including the Stirling engine. Is to provide.

  The Stirling engine according to the present invention has a back pressure space, a working space including a compression space and an expansion space, and is provided between the casing in which the working medium is sealed, and the back pressure space and the working space. A piston that applies pressure fluctuation to the working medium in the inside, a displacer that is provided between the compression space and the expansion space and that is operated by pressure fluctuation due to the piston, and is provided in the working space, with the displacer directed to a predetermined position. And a displacer spring.

  According to the above configuration, the displacer spring can be provided at a position close to the displacer by positioning the displacer spring for urging the displacer in the working space, so that the displacer spring can be fixed with a simple structure. As a result, the manufacturing cost of the Stirling engine is reduced.

  In the Stirling engine, the displacer spring may be provided in the compression space in the working space, or may be provided in the expansion space in the working space.

  In one aspect, the Stirling engine further includes a cylinder provided in the casing and reciprocally receiving the displacer, and the displacer spring is fixed to the cylinder.

  In another aspect, the Stirling engine further includes a cylinder provided in the casing and reciprocally receiving the piston, and the displacer spring is fixed to the cylinder.

  The displacer spring is preferably integrated with the cylinder by insert molding.

  Thereby, the positioning accuracy of the displacer spring is improved, and the number of parts and the number of assembly steps can be reduced.

  In yet another aspect, in the Stirling engine, the displacer spring is fixed to the casing.

  A Stirling engine-equipped device according to the present invention includes the Stirling engine described above.

  According to the present invention, since the displacer spring can be fixed with a simple structure, the manufacturing cost of the Stirling engine can be reduced.

  Embodiments of the present invention will be described below. Note that the same or corresponding parts are denoted by the same reference numerals, and the description thereof may not be repeated.

  Note that in the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. In the following embodiments, each component is not necessarily essential for the present invention unless otherwise specified. In addition, when there are a plurality of embodiments below, it is planned from the beginning to appropriately combine the configurations of the embodiments unless otherwise specified.

  In the specification of the present application, the “refrigerator” is a concept including all of the “refrigerator” having a refrigerator compartment, the “freezer” having a freezer compartment, and the “refrigerator refrigerator” having both the freezer compartment and the refrigerator compartment.

  In the example described later, a Stirling Refrigerator / Freezer as a Stirling engine-equipped device equipped with a Stirling refrigerator will be described. However, the Stirling engine-equipped device according to the present invention is limited to a Stirling refrigerator. It is not something. The Stirling engine is also used as a generator, for example.

(Description of Stirling refrigerator)
FIG. 1 is a piping system diagram of a Stirling cooler as a “Stirling engine-equipped device” including Stirling engines according to Embodiments 1 to 4 of the present invention to be described later.

  Referring to FIG. 1, a Stirling refrigerator 1000 includes a Stirling refrigerator 100 (Stirling engine) having a low temperature part and a high temperature part, and a low temperature side circulation circuit 200 that is a refrigerant circuit for transmitting the cold heat of the low temperature part. The first high temperature side circulation circuit 300 and the second high temperature side circulation circuit 400, which are refrigerant circuits for transmitting the heat of the high temperature part, are configured.

  The low temperature side circulation circuit 200 includes a low temperature side evaporator 210, refrigerant pipes 220 and 230, a low temperature side condenser 240 attached to a low temperature part of the Stirling refrigerator 100, and a fan 250. The low temperature side circulation circuit 200 performs heat exchange between the air in the refrigerator and the low temperature part of the Stirling refrigerator 100.

  In the low temperature side circulation circuit 200, carbon dioxide, hydrocarbons and the like are sealed as a refrigerant. The refrigerant condensed in the low temperature side condenser 240 flows through the refrigerant pipe 230 (low temperature side conduit) and reaches the low temperature side evaporator 210. Heat exchange is performed by evaporating the refrigerant in the low temperature side evaporator 210. In order to promote this heat exchange, a fan 250 is provided in the vicinity of the low temperature side evaporator 210 to generate an air flow. After the heat exchange, the gasified refrigerant returns to the low temperature side condenser 240 via the refrigerant pipe 220 (low temperature side return pipe). The refrigerant that has flowed into the low-temperature side condenser 240 and condensed flows into the refrigerant pipe 230.

  In the low-temperature side circulation circuit 200, the low-temperature side evaporator 200 can transmit cold heat generated in the low-temperature part of the Stirling refrigerator 100 using the natural circulation caused by the evaporation and condensation of the refrigerant. 210 is disposed below the low-temperature side condenser 240. Further, the pressure in the circulation circuit system is adjusted in order to adjust the boiling point of the refrigerant.

  The first high temperature side circulation circuit 300 includes a high temperature side condenser 310, refrigerant pipes 320 and 330, and a high temperature side evaporator 340. The first high temperature side circulation circuit 300 cools the high temperature part of the Stirling refrigerator 100.

Water (H ₂ O) or the like is sealed in the first high temperature side circulation circuit 300 as a refrigerant. The refrigerant evaporated in the high temperature side evaporator 340 flows through the refrigerant pipe 330 (high temperature side conduit) and reaches the high temperature side condenser 310. The refrigerant is condensed by heat exchange with the outside air in the high temperature side condenser 310. In order to promote this heat exchange, a fan 350 that generates an air flow in the vicinity of the high-temperature side condenser 310 is provided. The condensed refrigerant flows through the refrigerant pipe 320 (high temperature side return pipe) and returns to the high temperature side evaporator 340. In the first high temperature side circulation circuit 300, the high temperature side is used so that the heat generated in the high temperature portion of the Stirling refrigerator 100 can be transmitted using the natural circulation caused by the evaporation and condensation of the refrigerant. A condenser 310 is disposed above the high temperature side evaporator 340. Further, the pressure in the circulation circuit system is adjusted in order to adjust the boiling point of the refrigerant.

  The second high temperature side circulation circuit 400 includes refrigerant pipes 410, 430, 450, a circulation pump 420, and a dew prevention pipe 440. The second high temperature side circulation circuit 400 transmits the heat of the high temperature part of the Stirling refrigerator 100 to the dew condensation prevention pipe 440.

  The refrigerant pipe 410 is connected to the lower part of the high temperature side evaporator 340. Liquid phase refrigerant flows into the refrigerant pipe 410 from the high temperature side evaporator 340. The refrigerant that has flowed into the refrigerant pipe 410 reaches a circulation pump 420 provided below the Stirling refrigerator 100. The refrigerant discharged from the circulation pump 420 is sent to the dew prevention pipe 440 via the refrigerant pipe 430. The refrigerant flowing in the dew prevention pipe 440 is kept at a relatively high temperature by the heat given from the high temperature part of the Stirling refrigerator 100. Therefore, by providing the dew prevention pipe 440 on the front surface of the refrigerator, it is possible to suppress dew generation at the door portion and the like. The refrigerant that has flowed through the dew condensation prevention pipe 440 returns to the high temperature side evaporator 340 through the refrigerant pipe 450. Thus, in the 2nd high temperature side circulation circuit 400, the forced circulation by the circulation pump 420 is performed.

  When the Stirling refrigerator 100 is operated, the heat generated in the high temperature part of the refrigerator 100 is heat-exchanged with air via the high temperature side condenser 310. On the other hand, the cold generated in the low temperature part of the Stirling refrigerator 100 is heat exchanged with the air in the refrigerator through the low temperature side evaporator 210. The warmed airflow from the inside of the refrigerator is sent again to the vicinity of the low temperature side evaporator 210 and repeatedly cooled.

  In the example of FIG. 1, the Stirling refrigerator 100 is installed so that the high temperature portion and the low temperature portion in the Stirling refrigerator 100 are aligned in the horizontal direction (that is, horizontally). More specifically, the Stirling refrigeration is performed so that the high temperature part of the Stirling refrigerator 100 is positioned above the low temperature part of the Stirling refrigerator 100 so that the low temperature part is aligned in the vertical direction (that is, vertically). Machine 100 may be installed.

(Embodiment 1)
FIG. 2 is a side sectional view showing the Stirling engine according to the first embodiment. Referring to FIG. 2, Stirling refrigerator 100 (Stirling engine) according to the present embodiment is a free piston type Stirling engine, and includes casing 110 including high temperature portion 111 and low temperature portion 112, and casing 110. The assembled cylinder 120 (121, 122), the piston 130 and the displacer 140 that reciprocate in the cylinder 121, 122, the working space 150 including the compression space 151 and the expansion space 152, the regenerator 160, the heat The exchangers 161 and 162, the back pressure space 170, a linear motor 180 as a piston driving means, and a spring 190 including a piston spring 191 and a displacer spring 192 are configured.

  The casing 110 defines a back pressure space 170. Various parts including a cylinder 120, a linear motor 180, a piston spring 191 and a displacer spring 192 are assembled to the casing 110. The casing 110 is filled with a working medium such as helium gas, hydrogen gas, or nitrogen gas.

  The cylinders 121 and 122 have a substantially cylindrical shape, and receive therein a piston 130 and a displacer 140 as a free piston so as to be able to reciprocate. In the cylinder 120, the piston 130 and the displacer 140 are arranged coaxially with a space therebetween, and the piston 130 and the displacer 140 divide the working space 150 into a compression space 151 and an expansion space 152. More specifically, the working space 150 is a space located closer to the displacer 140 than the end face of the piston 130 on the displacer 140 side. A compression space 151 is formed between the piston 130 and the displacer 140, and the displacer 140 and the low temperature portion An expansion space 152 is formed between the two and 112. The compression space 151 is mainly surrounded by the high temperature part 111, and the expansion space 152 is mainly surrounded by the low temperature part 112.

  The piston 130 has a piston rod 130 </ b> A that protrudes from the axial end surface of the piston 130 toward the displacer 140. The piston rod 130 </ b> A is inserted through the displacer spring 192 and the displacer 140.

  Between the compression space 151 and the expansion space 152, a regenerator 160 in which a film is wound with a predetermined gap is disposed, and the compression space 151 and the expansion space are interposed via the regenerator 160. 152 communicates. Thereby, a closed circuit is configured in the Stirling refrigerator 100. The working medium sealed in the closed circuit flows in accordance with the operations of the piston 130 and the displacer 140, whereby a reverse Stirling cycle is realized.

  On the inner peripheral surfaces of the high temperature part 111 and the low temperature part 112, a heat exchanger 161 and a heat exchanger 162 are provided, respectively. The heat exchangers 161 and 162 perform heat exchange between the compression space 151 and the expansion space 152 and the high temperature portion 111 and the low temperature portion 112, respectively.

  A back pressure space 170 surrounded by the casing 110 is disposed on the opposite side of the piston 130 from the displacer 140. There is also a working medium in the back pressure space 170.

  A linear motor 180 is disposed in a portion of the back pressure space 170 located outside the cylinder 120. The linear motor 180 includes an inner yoke 181, an outer yoke 182 around which a coil is wound, and a movable magnet 183. The linear motor 180 drives the piston 130 in the axial direction of the cylinder 121.

  One end of the piston 130 is connected to a piston spring 191 composed of a leaf spring or the like. The piston spring 191 applies an elastic force to the piston 130. By applying an elastic force by the piston spring 191, the piston 130 can be reciprocated in the cylinder 121 more stably and periodically. The piston spring 191 is provided so as to be located in the back pressure space 170.

  One end of the displacer 140 is connected to a displacer spring 192 constituted by a leaf spring or the like. The displacer spring 192 imparts an elastic force to the displacer 140. By applying an elastic force by the displacer spring 192, the displacer 140 can be reciprocated in the cylinder 122 more stably and periodically. The displacer spring 192 is fixed to the cylinder 122 by, for example, a bolt and is provided so as to be located in the compression space 151 in the working space 150.

  Further, the displacer spring 192 may be integrated with the cylinder 122 by insert molding. By doing so, the positioning accuracy of the displacer spring 192 can be improved, and the number of parts and the number of assembly steps can be reduced.

Next, the operation of the Stirling refrigerator 100 will be described.
This refrigerator obtains a refrigeration effect using a so-called reverse Stirling cycle. The piston 130 is driven by a linear motor 180 to move sinusoidally. Due to the movement of the piston 130, the working medium in the compression space 151 exhibits a sinusoidal pressure change. The compressed working medium releases compression heat at the high temperature portion 111, is precooled when passing through the regenerator 160 provided outside the cylinder 120, and flows into the expansion space 152.

  The displacer 140 sine-moves with a constant phase difference in the same period as the piston 130 during steady operation, and the phase difference and amplitude are the spring constant of the displacer spring 192, the compression space 151 and the expansion space 152 that change from moment to moment. It is determined by the pressure difference, the mass of the displacer 140, the operating frequency, and the like. About this phase difference, it is generally said that the optimum condition is about 90 degrees.

  The working medium that has flowed into the expansion space 152 expands due to the sinusoidal movement of the displacer 140, whereby the temperature in the expansion space 152 is significantly reduced. By transmitting the extremely low temperature (for example, about −50 ° C.) generated at this time into the refrigerator through the low temperature portion 112, a desired cooling effect can be obtained.

  6 is a side sectional view showing a Stirling engine according to Comparative Example 1. FIG. With reference to FIG. 6, in the Stirling refrigerator 100 according to Comparative Example 1, a displacer spring 192 is provided in the back pressure space 170. For this reason, it is necessary to provide a displacer rod 140A that protrudes from the axial end surface of the displacer 140 on the compression space 151 side, penetrate the displacer rod 140A through the center hole of the piston 130, and extend to the back pressure space 170. While accuracy is required, the number of parts increases. As a result, the manufacturing cost of the Stirling engine increases.

  FIG. 7 is a side sectional view showing a Stirling engine according to Comparative Example 2. Referring to FIG. 7, in Stirling refrigerator 100 according to Comparative Example 2, rod member 122A is attached to cylinder 122, and rod member 122A is inserted into displacer 140 so as to reach the internal space of displacer 140. . A displacer spring 192 made of a coil spring is provided between the rod member 122 </ b> A reaching the inner space of the displacer 140 and the inner surface of the displacer 140. As described above, by adopting a structure in which the coil spring is attached to the inner space of the displacer 140, the displacer 140 needs to have higher strength, the manufacturing cost increases, and the capacity and reliability of the Stirling refrigerator 100 are increased. There is concern about the decline. Further, in the structure as shown in FIG. 7, when the Stirling refrigerator 100 is driven, a side load acts on the displacer 140, and there is a concern that the displacer 140 and the cylinder 122 may easily come into contact with each other.

  On the other hand, according to the Stirling refrigerator 100 according to the present embodiment, as shown in FIG. 2, the displacer spring 192 that biases the displacer 140 is positioned in the compression space 151, thereby displace the displacer spring 192. Since it can be provided at a position close to 140, the displacer spring 192 can be fixed with a simple structure. As a result, the manufacturing cost of the Stirling refrigerator 100 is reduced.

  The above contents are summarized as follows. That is, the Stirling refrigerator 100 as the “Stirling engine” according to the present embodiment has a back pressure space 170, a working space 150 including a compression space 151 and an expansion space 152, and a casing 110 in which a working medium is enclosed. The piston 130 is provided between the back pressure space 170 and the working space 150 and applies pressure variation to the working medium in the working space 150. The piston 130 is provided between the compression space 151 and the expansion space 152. A displacer 140 that operates by pressure fluctuation and a displacer spring 192 that is provided in the compression space 151 in the operating space 150 and biases the displacer 140 toward a predetermined position.

(Embodiment 2)
FIG. 3 is a side sectional view showing a Stirling engine according to the second embodiment. Referring to FIG. 3, the Stirling engine according to the present embodiment is a modification of the Stirling engine according to the first embodiment, and a displacer spring 192 is provided in expansion space 152 in working space 150. Features.

  In the Stirling refrigerator 100 according to the present embodiment, the displacer spring 192 is fixed to the cylinder 122 that receives the displacer 140. A rod member 122A is attached to the cylinder 122. The rod member 122A is inserted through the displacer 140.

  According to the Stirling refrigerator 100 according to the present embodiment, the displacer spring 192 that urges the displacer 140 is positioned in the expansion space 152, so that it is simple as with the Stirling refrigerator 100 according to the first embodiment. The displacer spring 192 can be fixed by the structure.

(Embodiment 3)
FIG. 4 is a side sectional view showing a Stirling engine according to the third embodiment. Referring to FIG. 4, the Stirling engine according to the present embodiment is a modification of the Stirling engine according to the first and second embodiments, and a displacer spring 192 provided in the compression space 151 in the working space 150 includes: It is fixed to a cylinder 121 that receives the piston 130.

  Also in the Stirling refrigerator 100 according to the present embodiment, by disposing the displacer spring 192 that biases the displacer 140 in the compression space 151, similarly to the Stirling refrigerator 100 according to the first and second embodiments, it is simple. The displacer spring 192 can be fixed by a simple structure.

(Embodiment 4)
FIG. 5 is a side sectional view showing a Stirling engine according to the fourth embodiment. Referring to FIG. 5, the Stirling engine according to the present embodiment is a modification of the Stirling engine according to the first to third embodiments, and a displacer spring 192 provided in the expansion space 152 in the working space 150 includes: It is fixed to the casing 110.

  Also in the Stirling refrigerator 100 according to the present embodiment, the displacer spring 192 that urges the displacer 140 is positioned in the expansion space 152, so that it is simple as in the Stirling refrigerator 100 according to the first to third embodiments. The displacer spring 192 can be fixed by a simple structure.

  Although the embodiments of the present invention have been described above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a piping system diagram of the Stirling cooler including the Stirling engine according to Embodiments 1 to 4 of the present invention. It is the sectional side view which showed the Stirling engine which concerns on Embodiment 1 of this invention. It is the sectional side view which showed the Stirling engine which concerns on Embodiment 2 of this invention. It is the sectional side view which showed the Stirling engine which concerns on Embodiment 3 of this invention. It is the sectional side view which showed the Stirling engine which concerns on Embodiment 4 of this invention. 1 is a side sectional view showing a Stirling engine according to Comparative Example 1. FIG. 5 is a side sectional view showing a Stirling engine according to Comparative Example 2. FIG.

Explanation of symbols

  100 Stirling refrigerator, 110 casing, 111 high temperature part, 112 low temperature part, 120, 121, 122 cylinder, 122A rod member, 130 piston, 130A piston rod, 140 displacer, 140A displacer rod, 150 working space, 151 compression space, 152 Expansion space, 160 regenerator, 161, 162 heat exchanger, 170 back pressure space, 180 linear motor, 181 inner yoke, 182 outer yoke, 183 movable magnet, 190 spring, 191 piston spring, 192 displacer spring, 200 low temperature side circulation Circuit, 210 low temperature side evaporator, 220, 230 refrigerant piping, 240 low temperature side condenser, 250 fan, 300 first high temperature side circulation circuit, 310 high temperature side condenser, 20,330 refrigerant pipe, 340 high-temperature side evaporator, 350 fans, 400 second high temperature side circulation circuit, 410,430,450 refrigerant pipe, 420 circulation pump 440 outburst prevention pipe, 1000 Stirling cooler.

Claims (8)

A casing having a back pressure space and a working space including a compression space and an expansion space, and enclosing the working medium;
A piston that is provided between the back pressure space and the working space, and applies pressure fluctuation to the working medium in the working space;
A displacer that is provided between the compression space and the expansion space and that operates by pressure fluctuations by the piston;
A Stirling engine comprising a displacer spring provided in the working space and biasing the displacer toward a predetermined position.   The Stirling engine according to claim 1, wherein the displacer spring is provided in the compression space in the working space.   The Stirling engine according to claim 1, wherein the displacer spring is provided in the expansion space in the working space. A cylinder provided in the casing and reciprocally receiving the displacer;
The Stirling engine according to any one of claims 1 to 3, wherein the displacer spring is fixed to the cylinder. A cylinder provided in the casing and reciprocally receiving the piston;
The Stirling engine according to any one of claims 1 to 3, wherein the displacer spring is fixed to the cylinder.   The Stirling engine according to claim 4 or 5, wherein the displacer spring is integrated with the cylinder by insert molding.   The Stirling engine according to any one of claims 1 to 3, wherein the displacer spring is fixed to the casing.   A Stirling engine-equipped device comprising the Stirling engine according to any one of claims 1 to 7.

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