JP5280325B2 - Multi-cylinder external combustion closed cycle heat engine with heat recovery device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device improving the thermal efficiency of an external combustion type closed cycle heat engine designed and manufactured under various conditions without relating the volume of a heater or a cooler to the efficiency of the engine. <P>SOLUTION: The cylinders of the external combustion type closed cycle heat engine are formed into a multiple cylinder type sharing a heater and a cooler. A heat exchanger is provided between flow passages on the side of the inlet of the heater and the side of the inlet of the cooler to recover quantity of heat. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to an external combustion type closed cycle heat engine that has a simple structure, high efficiency, and is easy to operate and maintain.
Specifically, the present invention relates to a multi-cylinder external combustion type closed cycle heat engine, which relates to a method for recovering heat and improving thermal efficiency.

  Stirling engines, regardless of the type of heat source, can effectively use energy that is currently wasted, and are quiet and low-pollution, so various types have been researched and developed, and are one of the important future heat engines. It is an external combustion type heat engine that is regarded as one of the most important.

A Stirling engine is an external combustion heat engine that obtains power by heating and cooling a working gas sealed in an air chamber to expand and contract the working gas.
In a conventional displacer type Stirling engine, the working gas is reciprocated between a heating part and a cooling part by reciprocating the displacer to heat and cool the working gas, that is, expand and contract, thereby operating a power piston. To gain power. The displacer is configured to interlock with the power piston in phase (Patent Document 2).

  However, in the conventional Stirling engine, the working gas in the air chamber, the heater and the cooler is pressurized and depressurized at the same time. Therefore, during heating, the working gas in the cooler is also pressurized to pressurize the air chamber. Also, during cooling, the working gas in the heater must be depressurized in order to depressurize the air chamber. For this reason, when the volume of the heater or the cooler is larger than the air chamber volume, the engine efficiency is lowered. Therefore, it is necessary to reduce the size of the heater and the cooler in order to increase the engine efficiency.

However, to operate the engine, it is necessary to take in and discharge the necessary amount of heat, and the heater and cooler must have sufficient capacity. In order to make the heater small and have sufficient capacity, there are means to reduce the thickness of the heat transfer surface and increase the heat transfer amount per area by raising the heating temperature, but it requires precise work and is expensive. It is necessary to use a new refractory metal, and the high temperature promotes corrosion of the heater.
In addition, the heater is not used during the cooling period, and the efficiency of the heater throughout the entire period is reduced, and the amount of external heat applied to the heater is wasted and the utilization efficiency is reduced. The same applies to the cooler during the heating period.

In view of the prior art as described above, the volume of the heater or cooler is not related to the efficiency of the engine, can be multi-cylinder, large, and high output, and can effectively use a low-temperature heat source, The inventors of the present invention have developed an external combustion type closed cycle heat engine that can be designed and manufactured under various conditions, and filed it earlier (Patent Document 1) (hereinafter referred to as “the present invention of the prior application”). ).
In the prior application of the present inventor, in particular, an external combustion closed cycle in which the heater and the cooler are used throughout the entire period without using the displacer piston used in the prior art (Patent Document 2). Proposed heat engine.
That is, in FIG. 2, a sealed air chamber 30, a heater 20, and a cooler 10 are provided, and flow paths 25 and 26 that are connected to the air chamber 30 and an inlet side and an outlet side of the heater 20 are provided, Flow paths 15 and 16 are provided to communicate with the air chamber 30 and the inlet side and the outlet side of the cooler 10, and the opening / closing valves 11, 21, 12 and 22 are provided in the flow paths 15, 25, 16 and 26 on the inlet side and the outlet side, respectively. The working gas moving means 50 is provided, the on-off valves 11 and 12 on the inlet side and the outlet side of the cooler 10 are closed, the cooler 10 is sealed, and the on-off valves 21 and 22 on the inlet side and the outlet side of the heater 20 are closed. Is opened and the working gas in the air chamber 30 is circulated through the heater 20 to heat the working gas in the air chamber 30, and the opening and closing valves 21 and 22 on the inlet side and the outlet side of the heater 20 are closed. While the cooler 10 entrance side and The opening / closing valves 11 and 12 on the mouth side are opened to circulate the working gas in the air chamber 30 through the cooler 10 to cool the working gas in the air chamber 30 and expand and contract the working gas in the air chamber 30. In the external combustion type closed cycle heat engine that drives the working body, the heater 20 automatically becomes a high pressure and the cooler 10 automatically becomes a low pressure in the cycle process.

41 is a piston cylinder provided in the lower part of the air chamber 30, 40 is a piston that slides in the piston cylinder 41, 42 is a flywheel fixed to the output shaft 46, and a crank mechanism 43 of the crank chamber 45. Thus, the piston 40 and the output shaft 46 are connected to constitute an action body. A cylinder having an air chamber and a working body is defined as a cylinder. Reference numeral 50 denotes a fan for moving the working gas provided in the upper part of the air chamber 30.
The configuration of FIG. 3 is different from the configuration of FIG. 2 in that the fan 50, which is a moving means for the working gas, is connected to the air chamber 30 and the inlet side of the cooler 10, and the flow path 15, the air chamber 30 and the inlet side of the heater 20. The on-off valves 21 and 22 on the inlet side and the outlet side of the heater 20 are replaced with one three-way valve 26, and the on-off valves 11 and 12 on the inlet side and the outlet side of the cooler 10 are arranged in one three-way. It replaces with the valve 25 and changes piping. The three-way valve is an on-off valve that selectively switches the flow from one direction to either one of the two directions, or selectively selects one of the two directions to switch to one direction. Has the same operation as that of FIG.

The purpose is to smooth the flow of the working gas in the air chamber 30 by reducing the number of openings to the air chamber 30 that are in conduction with the heater 20 and the cooler 10.
With the above configuration, the heater 20 is always at a high pressure, the cooler 10 is always at a low pressure, and the pressure change during the cycle is small. Therefore, even if the heater 20 and the cooler 10 are enlarged, the efficiency of the engine is small. For this reason, the heater 20 and the cooler 10 can be increased in size.

  Furthermore, since the heater 20 is always at a high pressure and the cooler 10 is always at a low pressure, a plurality of air chambers 30 are provided to form a multi-cylinder so that the heater 20 and the cooler 10 can be shared. In this case, since half of the cylinders can be heating periods and the other half can be cooling periods, the shared heater 20 and cooler 10 are always used. And the utilization efficiency of the cooler 10 is raised. Furthermore, the crank chamber 45 of each cylinder can be shared and integrated so as not to be affected by back pressure.

The configuration of FIG. 4 explains the configuration in which the inventor's prior invention is multi-cylinder.
In the figure, a plurality of cylinders A, B, C, and D share a single heater 20 and a cooler 10, and as a header on the inlet side of the heater 20, a heater inlet-side collective flow path 27, a heater outlet A heater outlet side collective flow path 28 as a header on the side, a cooler inlet side collective flow path 13 as a header on the cooler 10 inlet side, and a cooler outlet side collective flow path 14 as a header on the cooler outlet side, respectively. A three-way valve 23 is provided at the outlet side of each cylinder to selectively supply a working gas to the heater inlet side collective flow path 27 or the cooler inlet side collective flow path 13. The heater outlet side collective flow path 28 is provided at each cylinder inlet side. Alternatively, a three-way valve 24 for selectively flowing the working gas from the cooler outlet side collecting flow path 14 is provided.

  51 is a fan provided in the flow path 15 that conducts the cooler 10 and the cooler inlet-side collective flow path 13, and 52 is provided in the flow path 25 that conducts the heater 20 and the heater inlet-side collective flow path 27. It is a means for moving the working gas by the fan provided. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 4, and each of the cylinders A, B, C, and D includes an air chamber 30 and an action body. In FIG. 4, four cylinders are illustrated, but two or more cylinders and an odd number cylinder may be used.

The above operation will be described in detail.
Assume that half of the cylinders A and C are in the heating process and the other half of the cylinders B and D are in the cooling process. In FIG. 4, the flow of the working gas is indicated by arrows. The cylinder A is in the heating process, and the cylinder A → cylinder A outlet side three-way valve 23 is operated by the cylinder A outlet side three-way valve 23 and the cylinder A inlet side three-way valve 24 → the heater inlet side collective flow path 27 → Heater side fan 52 → heater 20 → heater outlet side collective flow path 28 → cylinder A inlet side three-way valve 24 → flow path of cylinder A, and the working gas in cylinder A is in the cooling process at the start of heating. Although the temperature is low because it is after the completion, it is circulated through this flow path by the action of the heater-side fan 52, heated by the heater 20, and returned to the cylinder A. The same applies to the cylinder C.

  The cylinder B is in the cooling process, and the cylinder B outlet side three-way valve 23 and the cylinder B inlet side three-way valve 24 cause the working gas to flow from the cylinder B → the cylinder B outlet side three-way valve 23 → the cooler inlet side collective flow path 13 → Cooler side fan 51 → cooler 10 → cooler outlet side collective flow path 14 → cylinder B inlet side three-way valve 24 → flow path of cylinder B, and the working gas in cylinder B is a heating process at the start of cooling. Although it is after completion, the temperature is high, but it circulates in this flow path by the action of the cooler side fan 51, is cooled by the cooler 10, and returns to the cylinder B. The same applies to the cylinder D.

  When the cylinders A and C finish the heating process and enter the cooling process, the cylinders B and D enter the heating process. Cylinder A is in the cooling process, and cylinder A → cylinder A outlet-side three-way valve 24 causes the working gas to flow from cylinder A → cylinder A outlet-side three-way valve 23 → cooler inlet-side collective flow path 13 → Cooler side fan 51 → cooler 10 → cooler outlet side collective flow path 14 → cylinder A inlet side three-way valve 24 → flow path of cylinder A, and the working gas in cylinder A is a heating process at the start of cooling. Although it is after completion, the temperature is high, but it circulates through this flow path by the action of the cooler side fan 51, is heated by the cooler 10, and returns to the cylinder A. The same applies to the cylinder C.

  The cylinder B is in the heating process, and the working gas is changed from the cylinder B → the cylinder B outlet side three-way valve 23 → the heater inlet side collective flow path 27 → by the cylinder B outlet side three-way valve 23 and the cylinder B inlet side three-way valve 24 → Heater side fan 52 → heater 20 → heater outlet side collective flow path 28 → cylinder B inlet side three-way valve 24 → flow path of cylinder B, and the working gas in cylinder B is in a cooling process at the start of heating. Although the temperature is low because it is after the completion, it is circulated through this flow path by the action of the heater-side fan 52, heated by the heater 20, and returned to the cylinder B. The same applies to the cylinder D.

Japanese Patent Application No. 2009-008570 JP 2006-275018 A

  In the external combustion type closed cycle heat engine, during heating, the on-off valves 11 and 12 on the inlet side and the outlet side of the cooler 10 are closed to close the cooler 10, and the on-off valves 21 on the inlet side and the outlet side of the heater 20 are closed. 22 is opened and the working gas in the air chamber 30 is circulated through the heater 20, and when the working gas in the air chamber 30 is heated and expanded, the working gas is continuously circulated until the piston 40 reaches the bottom dead center. During cooling, the opening and closing valves 21 and 22 on the inlet side and the outlet side of the heater 20 are closed to seal the heater 20, and the opening and closing valves 11 and 12 on the inlet side and outlet side of the cooler 10 are opened to operate in the air chamber 30. When the gas is circulated through the cooler 10 to cool and contract the working gas in the air chamber 30, if the working gas is circulated until the piston 40 reaches the top dead center, the thermodynamic cycle is an isothermal process (during heating). , Working gas Isothermal expansion, cooling, and working gas is being isothermal compression.), A pressure difference generated becomes low.

  In the above engine, the opening / closing valves 21, 22, 11, and 12 of the heater 20 and the cooler 10 are closed during the piston stroke to isolate the air chamber 30 from the heater 20 and the cooler 10. After the circulation is stopped, the piston 40 can be pushed down or pushed up by the adiabatic change of only the working gas in the air chamber 30. If the on-off valves 21, 22, 11, and 12 are closed at the same position of the piston stroke during heating and cooling and the working gas circulation is stopped, the pressure difference generated increases, but the thermodynamic cycle is partially insulated It becomes a process.

In the above engine, the thermodynamic cycle can be composed of various cycles such as an isothermal process, a cycle including a part of adiabatic process, and this is also a feature of the engine.
In any cycle, the hot working gas existing in the air chamber 30 and the piston cylinder 41 at the end of the heating process moves into the cooler 10 and is cooled as the cooling process starts. In this process, the amount of heat that the hot working gas has is carried away from the system. It is an object of the present invention to provide an external combustion type closed cycle heat engine that collects a part of this heat amount and feeds back to the heating process to improve the thermal efficiency.

The inventors of the present invention have intensively studied to solve the above problems, and as a result, have completed the invention having the following configuration.
The invention of claim 1 is provided with a sealed air chamber, a heater, and a cooler, provided with a flow path that communicates with the air chamber and an inlet side and an outlet side of the heater, and the air chamber and the cooler. Provide a flow path that communicates with the inlet side and the outlet side, provide an open / close valve in the flow path on the inlet side and the outlet side of each air chamber, provide a means for moving the working gas in the flow path, The on-off valve is closed and the cooler is sealed. The on-off valves on the inlet and outlet sides of the heater are opened and the working gas in the air chamber is circulated through the heater to heat the working gas in the air chamber. And the on-off valve on the outlet side is closed to seal the heater, while the on-off valves on the inlet side and outlet side of the cooler are opened to circulate the working gas in the air chamber through the cooler to cool the working gas in the air chamber, Outside the single cylinder that drives the working body by expanding and contracting the working gas in the air chamber Multi-cylinder external combustion type closed cycle heat engine in which a plurality of closed-cycle heat engine cylinders are arranged, each cylinder sharing a heater and a cooler, and between the flow paths on the heater inlet side and the cooler inlet side It has been found that the above-mentioned problems can be realized.

  In the multi-cylinder external combustion type closed cycle heat engine with a heat recovery device of the present invention, a multi-cylinder in which a plurality of cylinders are arranged share a heater and a cooler, and heat is generated between the flow paths on the heater inlet side and the cooler inlet side. Since the exchanger is provided, heat is transferred to the low-temperature working gas after completion of cooling supplied to the heater by the high-temperature working gas after completion of heating supplied to the cooler. The heat efficiency can be increased because a part of the amount of heat originally flowing out of the cooler can be efficiently recovered and reused.

The conceptual diagram which shows the Example of the multicylinder external combustion type closed cycle heat engine with the heat recovery apparatus of this invention Explanatory drawing of the external combustion type closed cycle heat engine concerning prior invention of this inventor Explanatory drawing of the external combustion type closed cycle heat engine concerning prior invention of this inventor Explanatory drawing of the external combustion type closed cycle heat engine concerning prior invention of this inventor Schematic cross-sectional view at VV in FIG.

  Hereinafter, specific modes for carrying out the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals are assigned to the same parts as those assigned in the prior application invention. Moreover, the arrow in a figure shows the flow direction of a working gas when an on-off valve etc. are in a continuous line state.

FIG. 1 is a conceptual diagram showing an embodiment of a multi-cylinder external combustion type closed cycle heat engine with a heat recovery device of the present invention.
In the figure, a plurality of cylinders A, B, C, and D share a single heater 20 and a cooler 10, and as a header on the inlet side of the heater 20, a heater inlet-side collective flow path 27, a heater outlet A heater outlet side collective flow path 28 as a header on the side, a cooler inlet side collective flow path 13 as a header on the cooler 10 inlet side, and a cooler outlet side collective flow path 14 as a header on the cooler outlet side, respectively. A three-way valve 23 is provided at the outlet side of each cylinder to selectively supply a working gas to the heater inlet side collective flow path 27 or the cooler inlet side collective flow path 13. The heater outlet side collective flow path 28 is provided at each cylinder inlet side. Alternatively, a three-way valve 24 for selectively flowing the working gas from the cooler outlet side collecting flow path 14 is provided. 51 is a fan provided in the flow path 15 that conducts the cooler 10 and the cooler inlet-side collective flow path 13, and 52 is provided in the flow path 25 that conducts the heater 20 and the heater inlet-side collective flow path 27. It is a means for moving the working gas by the fan provided. 70 includes a heat exchanger 71 provided therein, a flow path 72 that communicates with the cooler inlet-side collective flow path 13 and the flow path 15, and a flow path 73 that communicates with the heater inlet-side collective flow path 27 and the flow path 25. Is a heat recovery device provided. The installation positions of the fans 51 and 52 may be upstream or downstream of the heat recovery apparatus 70. In addition, although four cylinders (even numbers) are illustrated here, the number of cylinders may be an odd number of 3 or more in principle. That is, the total cylinder volume only needs to be balanced between the heating process and the cooling process.

The schematic cross-section of each cylinder in FIG. 1 is the same as the cross-sectional view along VV in FIG. 4 (FIG. 5).
In the figure, 41 is a piston cylinder provided in the lower part of the air chamber 30 above the cylinder, 40 is a piston sliding inside the piston cylinder 41, 42 is a flywheel fixed to the output shaft 46, a crank chamber The piston 40 and the output shaft 46 are connected via a crank mechanism 43 of 45 to constitute an action body. The crank mechanism 43, the rotation shaft 46, and the flywheel 42 are housed in a sealed crank chamber 45. If the air chamber 30 is electrically connected to the heater 20, the inside of the air chamber 30 becomes high temperature and high pressure, and the piston 40 descends. Further, if the air chamber 30 is electrically connected to the cooler 10, the inside of the air chamber 30 becomes low temperature and low pressure, and the piston 40 rises.

The above operation will be described. Assume that half of the cylinders A and C are in the heating process, and the other half of the cylinders B and D are in the cooling process.
Cylinder A is in the heating process, and cylinder A → cylinder A outlet side three-way valve 24 is connected to cylinder A → cylinder A outlet side three-way valve 23 → heater inlet side collective flow path 27 → heater side fan. 52 → heater 20 → heater outlet side collective flow path 28 → cylinder A inlet side three-way valve 24 → cylinder A flow path is formed. The working gas in the cylinder A is at a low temperature because it is after the end of the cooling process at the start of heating, but circulates in the flow path by the action of the heater side fan 52 and is heated by the heater 20 to the cylinder A. Return. The same applies to the cylinder C.
Cylinder B is in the cooling process, and cylinder B → cylinder B outlet side three-way valve 24 → cylinder B → cylinder B outlet side three-way valve 23 → cooler inlet side collective flow path 13 → cooler side fan 51 → Cooler 10 → Cooler outlet side collecting flow path 14 → Cylinder B inlet side three-way valve 24 → Cylinder B flow path is formed. The working gas in the cylinder B is hot because it is after the heating process is finished at the start of cooling, but circulates in the flow path by the action of the cooler side fan 51 and is cooled by the cooler 10 to the cylinder B. Return. The same applies to the cylinder D.

  When the cylinders A and C finish the heating process and enter the cooling process, the cylinders B and D enter the heating process. Cylinder A is in a cooling process, and cylinder A → cylinder A outlet side three-way valve 23 → cylinder A outlet side three-way valve 23 → cooler inlet side collective flow path 13 → cooler side fan 51 → Cooler 10 → Cooler outlet side collective flow path 14 → Cylinder A inlet side three-way valve 24 → Cylinder A flow path is formed. The working gas in the cylinder A is at a high temperature because it is after the end of the heating process at the start of cooling, but circulates in the flow path by the action of the cooler-side fan 51 and is heated by the cooler 10 to return to the cylinder A. . The same applies to the cylinder C.

Cylinder B is in a heating process, and cylinder B → cylinder B outlet side three-way valve 23 → cylinder B outlet side three-way valve 23 → heater inlet side collecting flow path 27 → heater side fan 52 → heater 20 → heater outlet side collective flow path 28 → cylinder B inlet side three-way valve 24 → cylinder B flow path is formed. The working gas in the cylinder B is at a low temperature because it is after the cooling process is finished at the start of heating, but circulates in the flow path by the action of the heater-side fan 52 and is heated by the heater 20 to return to the cylinder B. . The same applies to the cylinder D.
Accordingly, a low-temperature working gas always flows through the heater inlet-side collecting flow path 27, and a high-temperature working gas always flows through the cooler inlet-side collecting flow path 13. Since the heat exchanger 71 is provided in the heat recovery apparatus 70 between the heater inlet-side collective flow path 27 and the cooler inlet-side collective flow path 13, the low-temperature operation flowing through the heater inlet-side collective flow path 27 is performed. The gas is heated by the high-temperature working gas flowing through the cooler inlet side collecting flow path 13 and supplied to the heater 20, and the load on the heater is reduced. Similarly, the cooler load is reduced and the thermal efficiency of the system is improved.

  If the fans 51, 51, which are moving gas moving means in FIG. 1, are other moving means, and a volumetric compressor (not shown) such as a roots blower, the roots blower is used as the multi-cylinder external combustion closed cycle heat engine. By driving with the output shaft 46, the moving amount of working gas per cycle can be made constant. After the heating process is finished, the high-temperature and high-pressure gas existing in the cylinder passes from the cylinder through the three-way valve 23 and moves to the cooler 10, and at the same time, the low-temperature and low-pressure gas supplied from the cooler 10 passes through the three-way valve 24 and passes through the cylinder. A cooling process is performed in which the three-way valve 23 is switched before it reaches the three-way valve 23 after filling, and the low-temperature and low-pressure gas existing in the cylinder passes through the three-way valve 23 and moves to the superheater 20 after the cooling process ends. At the same time, the high-temperature high-pressure gas supplied from the heater 20 passes through the three-way valve 24, passes through the cylinder, passes through the cylinder, and performs a heating process for switching the three-way valve 23 before reaching the three-way valve 23. Since the high temperature working gas always flows in the flow path 13 and the low temperature working gas always flows in the heater inlet side collective flow path 27, the cooler inlet side collective flow path 13 and the heater inlet side collective flow path 27 Provided on the exit side The amount of heat to heat the low-temperature working gas supplied to the heater 20 by the heat exchanger 71 of the heat recovery unit 70 can be efficiently recovered was.

DESCRIPTION OF SYMBOLS 10 Cooler 11, 12, 21, 22 On-off valve 13 Cooler inlet side collecting flow path 14 Cooler outlet side collecting flow path 15, 16, 25, 26 Flow path 20 Heater 27 Heater inlet side collecting flow path 28 Heating Outlet collecting flow path 23, 24, 25, 26 Three-way valve 30 Air chamber 40 Piston 41 Piston cylinder 42 Flywheel 43 Crank mechanism 45 Crank chamber 46 Output shaft 50, 51, 52 Fan 70 Heat recovery device 71 Heat exchanger 72 73 channels

Claims (1)

  A sealed air chamber, a heater and a cooler are provided, and a flow path is provided to connect the air chamber to the inlet side and the outlet side of the heater, and the air chamber is connected to the inlet side and the outlet side of the cooler. The flow path is provided, the opening and closing valves are provided in the inlet and outlet flow paths of the air chambers, the working gas moving means is provided in the flow path, and the opening and closing valves on the cooler inlet and outlet sides are closed. The opening and closing valves on the inlet and outlet sides of the heater are opened and the working gas in the air chamber is circulated through the heater to heat the working gas in the air chamber, and the opening and closing valves on the inlet and outlet sides of the heater are opened. The heater is sealed as closed, while the opening and closing valves on the inlet side and outlet side of the cooler are opened, and the working gas in the air chamber is circulated through the cooler to cool the working gas in the air chamber, and the working gas in the air chamber is expanded. Single cylinder external combustion type closed cylinder that operates by contracting This is a multi-cylinder external combustion type closed-cycle heat engine in which multiple cylinders of the heat engine are arranged. Each cylinder shares a heater and a cooler, and heat is generated between the flow paths on the heater inlet side and the cooler inlet side. A multi-cylinder external combustion type closed cycle heat engine with a heat recovery device, characterized in that an exchanger is provided.

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