JP6936771B2 - Stirling engine - Google Patents

Description

The present invention relates to a Stirling engine.

In Patent Document 1 below, in a Stirling engine in which a heating part of a Stirling engine is arranged in a flue of an incinerator or the like and the exhaust gas is used as a heat source, the heater tube as the heating part exposed to the flue is abnormally heated. , Since there is a risk of damage, the necessity of measures against abnormal heating of the heater tube will be disclosed.

However, although Patent Document 1 discloses that the pressure of the operating medium is changed by the pressure control device as a countermeasure against abnormal heating of the heater tube, it does not disclose any specific configuration thereof.

Japanese Unexamined Patent Publication No. 2000-45865

Therefore, in view of the above problems, it is an object of the present invention to provide a Stirling engine capable of suppressing overheating of a heating portion when driving waste heat as a heat source.

The Stirling engine of the present invention includes a reciprocating display piston and a power piston.
A crankshaft connected to the displacer piston and power piston,
A crankcase that supports the crankshaft and
The heating part exposed to the heat source part and
A temperature sensor that detects the temperature of the heating unit and
An output sensor that detects the output of the engine and
A first communication path communicating with the compression space of the power piston and the inside of the crankcase,
The first on-off valve provided in the first communication path and
A control unit that controls the opening and closing of the first on-off valve,
A check valve, which is provided in parallel with the first on-off valve and has a forward direction from the inside of the crankcase toward the compression space, is provided.
When the temperature of the heating unit based on the detection temperature of the temperature sensor is less than the upper limit temperature and the output based on the detection output of the output sensor is equal to or more than the upper limit output larger than the rated output, the control unit has the rated output. The first on-off valve is opened until the lower limit output is smaller than the output.

According to the present invention, the output of the engine can be adjusted to near the rated output. By driving the engine near the rated output, which is the maximum output for normal use, the maximum endothermic heat can be obtained from the heating unit, so that the cooling effect of the heating unit can be maintained to the maximum. As a result, overheating of the heating portion can be suppressed when the waste heat is driven as a heat source.

Further, the Stirling engine of the present invention includes a reciprocating display piston and a power piston.
A crankshaft connected to the displacer piston and power piston,
A crankcase that supports the crankshaft and
The heating part exposed to the heat source part and
A temperature sensor that detects the temperature of the heating unit and
An output sensor that detects the output of the engine and
A first communication path communicating with the compression space of the power piston and the inside of the crankcase,
The proportional valve provided in the first communication path and
A control unit that controls the opening degree of the proportional valve and
A check valve, which is provided in parallel with the proportional valve and has a forward direction from the inside of the crankcase toward the compression space, is provided.
When the heating unit temperature based on the detection temperature of the temperature sensor is less than the upper limit temperature and the output based on the detection output of the output sensor is less than the upper limit output larger than the rated output, the control unit becomes the rated output. As described above, the opening degree of the proportional valve is controlled.

According to the present invention, the output of the engine can be adjusted to near the rated output. By driving the engine near the rated output, which is the maximum output for normal use, the maximum endothermic heat can be obtained from the heating unit, so that the cooling effect of the heating unit can be maintained to the maximum. As a result, overheating of the heating portion can be suppressed when the waste heat is driven as a heat source.

Further, the Stirling engine of the present invention includes a reciprocating display piston and a power piston.
The heating part exposed to the heat source part and
A temperature sensor that detects the temperature of the heating unit and
A second communication path that communicates with the expansion space of the display piston and the outside,
A blower provided in the second communication path and blowing air into the expansion space,
A second on-off valve provided in the second communication path on the expansion space side of the blower, and
A third on-off valve that switches whether or not the compression space of the power piston is communicated to the outside,
A control unit for controlling the operation of the blower, the opening / closing of the second on-off valve, and the opening / closing of the third on-off valve are provided.
When the temperature of the heating unit based on the temperature detected by the temperature sensor is equal to or higher than the upper limit temperature, the control unit opens the second on-off valve and the third on-off valve until the temperature of the heating unit becomes equal to or lower than a predetermined temperature. It operates a blower.

In the Stirling engine of the present invention, the control unit opens the third on-off valve when the temperature of the heating unit based on the temperature detected by the temperature sensor is equal to or higher than the upper limit temperature, and the pressure in the compression space is set to a predetermined pressure or lower. It is preferable to open the second on-off valve and operate the blower after the temperature has changed or after a predetermined time has elapsed.

According to the present invention, by opening the second on-off valve and the third on-off valve and operating the blower, the outside air is supplied to the expansion space, and the heating portion communicating with the expansion space can be cooled. As a result, overheating of the heating portion can be suppressed when the waste heat is driven as a heat source.

It is the schematic which shows the side cross section of the Stirling engine which concerns on 1st Embodiment. It is the schematic which shows the front cross section of the Stirling engine which concerns on 1st Embodiment. It is a flowchart which shows the procedure of control of the engine output which concerns on 1st Embodiment. It is a graph which shows an example of the control of the engine output which concerns on 1st Embodiment. It is a flowchart which shows the procedure of control of the engine output which concerns on 2nd Embodiment. It is a graph which shows an example of the control of the engine output which concerns on 2nd Embodiment. It is the schematic which shows the side cross section of the Stirling engine which concerns on 3rd Embodiment. It is a flowchart which shows the heater cooling process which concerns on 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic view showing a side cross section of the Stirling engine 1, and FIG. 2 is a schematic view showing a front cross section of the Stirling engine 1. In the following, the β-type Stirling engine 1 will be described as an example.

As shown in FIGS. 1 and 2, in the Stirling engine 1, the displacer piston 3 and the power piston 4 are housed in a cylinder 2 in which working gases such as air, helium gas, and hydrogen are filled so as to be reciprocating. ing.

The cylinder 2 has a configuration in which one end is opened while the other end is closed, and the displacer piston 3 is arranged on the closed end side, while the power piston 4 is arranged on the open end side. In the cylinder 2, an expansion space 5 is formed between the closed end portion and the display support piston 3, and a compression space 6 is formed between the display support piston 3 and the power piston 4. The expansion space 5 and the compression space 6 in the cylinder 2 are collectively referred to as an operating space.

The Stirling engine 1 is provided with a heat exchanger 7 that raises and lowers the temperature of the working gas in the working space in the cylinder 2. The heat exchanger 7 communicates with the expansion space 5 to heat the working gas by heat input from the outside (corresponding to a heating part), and communicates with the compression space 6 to dissipate the working gas to the outside. A cooler 9 for cooling and a regenerator 10 for connecting the heater 8 and the cooler 9 are provided. When the displacer piston 3 moves toward the open end side of the cylinder 2, the working gas heated by the heater 8 flows into the expansion space 5, and the temperature of the working gas rises. On the other hand, when the displacer piston 3 moves toward the closed end side of the cylinder 2, the working gas cooled by the cooler 9 flows into the compression space 6, and the temperature of the working gas drops. Therefore, the working gas flows in the working space between the heat exchanger 7 and the cylinder 2 in the forward and reverse directions, so that the internal pressure in the working space of the cylinder 2 changes, and the reciprocating movement of the power piston 4 is promoted.

One end of the heater 8 communicates with the expansion space 5, and the other end communicates with one end of the regenerator 10. The heater 8 heats the working gas passing through the inside by receiving the heat of the exhaust gas generated in the incinerator or the like. Although only two tubular heaters 8 are shown in FIGS. 1 and 2, a large number (three or more) of heaters 8 are actually provided. The heater 8 is provided with a temperature sensor (not shown), and the temperature of the heater 8 can be detected by the temperature sensor. As the temperature sensor, for example, a thermocouple is used. The temperature of the heater 8 detected by the temperature sensor is input to a control unit (not shown).

The other end of the regenerator 10 communicates with the cooler 9. Further, the cooler 9 communicates with the compression space 6. Cooling water flows in the cooler 9 so as to be heat exchangeable with the working gas, and the working gas is cooled by this heat exchange.

The regenerator 10 and the cooler 9 are arranged on the outer peripheral portion of the cylinder 2. In FIG. 1, a part of the regenerator 10 and the cooler 9 is omitted. The regenerator 10 is composed of, for example, one in which metal fibers and wire mesh are laminated, one in which the flow paths of working gas are arranged in a honeycomb shape, and one in which cotton-like metal fibers are included. Functions as a heat storage type heat exchanger. That is, the regenerator 10 stores heat of the working gas when the high-temperature working gas flows from the heater 8 to the cooler 9, while the regenerator 10 stores heat when the low-temperature working gas flows from the cooler 9 to the heater 8. The generated heat is dissipated to the working gas.

The Stirling engine 1 is provided with an output extraction device 11 on the open end side of the cylinder 2 that converts the reciprocating motion of the power piston 4 into a rotary motion and outputs rotary power. The output take-out device 11 pivotally supports a crankshaft 12 connected to each of the displacer piston 3 and the power piston 4 in the crankcase 13. Then, one end side of the crankshaft 12 serves as an output shaft, which is connected to the input shaft 16 of the generator 15 via the flywheel 14 in the crankcase 13. Further, a buffer space 17 is formed by a space 17a on the opening end side of the power piston 4 in the cylinder 2 and a space 17b in the crankcase 13.

By connecting the displacer piston 3 and the power piston 4 to the crankshaft 12 of the output extraction device 11, the displacer piston 3 and the power piston 4 reciprocate in the cylinder 2 with a predetermined phase difference from each other. In this embodiment, the phase difference in the reciprocating operation of the display piston 3 and the power piston 4 is 90 °.

The output take-out device 11 includes a plate 51c fixed to the crankshaft guide groove (through groove) 51a of the displayer piston yoke 51 that reciprocates according to the display piston 3, and a power piston yoke that reciprocates according to the power piston 4. Crankpins 54 to 56 of the crankshaft 12 are fitted to the plates 52c and 53c fixed to the crankshaft guide grooves (through grooves) 52a and 53a of the reciprocating parts) 52 and 53 via bearings 57 to 59, respectively. It is composed of a scotch yoke mechanism.

As shown in FIG. 2, the display support piston yoke 51 is provided with a long crankshaft guide groove 51a in the central portion thereof in a direction (lateral direction) intersecting the axial directions of the crankshaft 12 and the display support piston 3. There is. Reciprocating guide holes (through holes) 51b are bored in the displayer piston yoke 51 on both sides of the crankshaft guide groove 51a in the axial direction (longitudinal direction) of the displayer piston 3. A guide shaft 60 fixed to the crankcase 13 is inserted into the reciprocating guide hole 51b of the displacer piston yoke 51 via a linear motion bearing 63 such as a rotor rib bushing. The display support piston yoke 51 is connected to the other end of the rod 66 whose one end is connected to the display support piston 3, and reciprocates in the same direction (vertical direction) as the display support piston 3 in accordance with the reciprocating movement of the display support piston 3.

As shown in FIG. 2, the power piston yoke 52 is provided with a crankshaft guide groove 52a long in the lateral direction in the central portion thereof, and reciprocating guide holes (reciprocating guide holes) are provided on both sides of the crankshaft guide groove 52a. (Through hole) 52b is bored in the vertical direction. A guide shaft 61 fixed to the crankcase 13 is inserted into the reciprocating guide hole 52b of the power piston yoke 52 via a linear motion bearing 64. The power piston yoke 52 is connected to the other end of the bridge 67 whose one end is connected to the power piston 4, and reciprocates in the vertical direction in accordance with the reciprocating movement of the power piston 4. Since the power piston yoke 53 has the same shape as the power piston yoke 52, detailed description thereof will be omitted.

As shown in FIGS. 1 and 2, through holes 4a and 67a are provided at the centers of the power piston 4 and the bridge 67 in the direction (longitudinal direction) along the axial direction of the power piston 4, and the display piston 3 and the display piston 3 are provided. The connected rod 66 is pierced. The rod 66 is movable relative to the power piston 4 and the bridge 67, and a dynamic sealing mechanism (not shown) such as a mechanical seal is configured at the insertion portion of the rod 66 in the power piston 4.

As shown in FIG. 1, the crankshaft 12 is connected between the bridge 67 and the crank pins 55 and 56 connected via the power piston yokes 52 and 53, and the crank pin 54 connected via the rod 66 and the displacer piston yoke 51. Is provided, and the crank pin 54 is attached to the crank pins 55 and 56 having the same phase with a predetermined phase difference (for example, 90 °). A bridge insertion hole 68 into which the bridge 67 is inserted is provided in the connecting portion of the crankcase 13 with the cylinder 2. The bridge insertion hole 68 of the crankcase 13 is formed in a connecting portion between the cylinder 2 and the crankcase 13, so that the cylinder 2 side portion of the bridge 67 is inserted and removed from the bridge insertion hole 68 so that the bridge 67 is inserted and removed. Reciprocates according to the power piston 4. In order to reduce the fluctuation of the internal pressure due to the volume change due to the reciprocating movement of the power piston 4 in the buffer space 17a on the opening end side of the power piston 4 in the cylinder 2, the buffer space 17a in the cylinder 2 and the inside of the crankcase 13 A communication port 17d is provided between the buffer space 17b and the buffer space 17b.

The displacer piston 3 reciprocates with the rotational power of the crankshaft 12, and the working gas moves back and forth between the expansion space 5 and the compression space 6, so that the internal pressure of the working space changes. Due to this pressure change, the power piston 4 reciprocates, and the reciprocating power is transmitted to the power piston yokes 52 and 53 via the bridge 67. As a result, the power piston yokes 52 and 53 reciprocate in the vertical direction along the guide shafts 61 and 62, respectively. Then, the reciprocating motion of the power piston yokes 52 and 53 causes the crankshafts 12 to rotate by reciprocating in the lateral direction while the crankpins 55 and 56 rotate in the crankshaft guide grooves 52a and 53a, respectively. Therefore, the output take-out device 11 that receives the reciprocating power of the power piston 4 converts it into rotational power by the Scotch yoke mechanism and outputs it from the crank shaft 12, and rotates the generator 15 via the flywheel 14 and the input shaft 16. Let me.

The Stirling engine 1 includes an output sensor (not shown) that detects the output of the engine. The output sensor may be a sensor capable of measuring a physical quantity corresponding to the output of the engine, such as a sensor for measuring the rotation speed of the crank shaft 12 or the input shaft 16 and a sensor for measuring the amount of power generated by the generator 15. The output of the Stirling engine 1 detected by the output sensor is input to a control unit (not shown).

The Stirling engine 1 includes a first communication path 71 that communicates with the compression space 6 and the inside of the crankcase 13. One end of the first communication path 71 is connected to the cylinder 2 and the other end is connected to the crankcase 13. Further, the other end of the first connecting path 71 is connected to the upper part in the vertical direction of the liquid level of the lubricating oil in the crankcase 13. By providing the first communication path 71, the working gas can flow back and forth between the compression space 6 and the inside of the crankcase 13.

The first communication path 71 is provided with a first on-off valve 72 and a check valve 73. The first on-off valve 72 and the check valve 73 are arranged in parallel. The first on-off valve 72 can communicate or shut off the first communication path 71. The check valve 73 is arranged so that the direction from the inside of the crankcase 13 toward the compression space 6 is the forward direction.

By providing the first on-off valve 72 and the check valve 73, when the first on-off valve 72 is opened, the working gas in the working space (expansion space 5 and compression space 6) enters the crankcase via the first communication path 71. Since it moves into 13, the output of the engine can be reduced. On the other hand, when the first on-off valve 72 is closed, the check valve 73 allows only the movement of the working gas from the inside of the crankcase 13 to the working space, so that the output of the engine can be gradually increased. By opening and closing the first on-off valve 72 in this way, the output of the engine can be adjusted.

Next, the control method of the Stirling engine 1 will be described. FIG. 3 is a flowchart showing a procedure for controlling engine output. FIG. 4 is a graph showing an example of engine output control.

First, in step S11, the output P of the engine and the temperature Th of the heater 8 are detected. The output P of the engine is detected by the output sensor, and the temperature Th of the heater 8 is detected by the temperature sensor. The output P detected by the output sensor and the temperature Th detected by the temperature sensor are input to the control unit.

In the next step S12, the control unit determines whether or not the output P of the engine is equal to or higher than the upper limit output P1. The upper limit output P1 is set based on the rated output P2 of the engine, and is set to, for example, 105 to 110% of the rated output P2. As shown in FIG. 4, when the temperature of the exhaust gas (heat source gas) as a heat source is overheated due to some abnormality and rises, the temperature Th of the heater 8 and the output P of the engine also rise accordingly. Then, as shown in FIG. 4, when the output P of the engine becomes the upper limit output P1 or more (Yes in step S12), the process proceeds to the next step S13.

In the next step S13, the control unit determines whether or not the period in which the temperature Th of the heater 8 is equal to or higher than the allowable temperature T1 continues for t2 seconds. The permissible temperature T1 is set based on the temperature at which the heater 8 causes thermal deterioration. In the present invention, the temperature Th of the heater 8 is equal to or higher than the upper limit temperature means a state in which the temperature Th of the heater 8 is equal to or higher than the allowable temperature T1 for t2 seconds. If the temperature Th of the heater 8 becomes equal to or higher than the upper limit temperature, there is a risk of thermal deterioration. In step S13, when it is determined that the period in which the temperature Th of the heater 8 becomes the allowable temperature T1 or higher continues for t2 seconds (Yes in step S13), the heater 8 described later is cooled in order to suppress thermal deterioration. Perform processing. On the other hand, when it is determined that the period in which the temperature Th of the heater 8 becomes the allowable temperature T1 or more does not continue for t2 seconds (No in step S13), the process proceeds to the next step S14.

In the next step S14, the control unit instructs the first on-off valve 72 to open. After opening the first on-off valve 72, the process returns to step S11.

When the first on-off valve 72 is opened in step S14, the engine output P decreases as shown in FIG. 4, the engine output P becomes less than the upper limit output P1 (No in step S12), and the process proceeds to step S15.

In the next step S15, the control unit determines whether or not the output P of the engine is equal to or less than the lower limit output P3. The lower limit output P3 is set based on the rated output P2 of the engine, and is set to, for example, 90 to 95% of the rated output P2. If the engine output P is equal to or less than the lower limit output P3 (Yes in step S15), the process proceeds to the next step S16.

In the next step S16, the control unit instructs the first on-off valve 72 to close. When the first on-off valve 72 is closed, the check valve 73 increases the output P of the engine as shown in FIG. After closing the first on-off valve 72 in step S16, the process returns to step S11 to detect the output P of the engine and the temperature Th of the heater 8.

On the other hand, when the engine output P is larger than the lower limit output P3 in step S15 (No in step S15), the process returns to step S11 and the open state of the first on-off valve 72 is maintained until the engine output P becomes the lower limit output P3 or less. do. With the above control, the output P of the engine can be adjusted to the vicinity of the safe rated output P2.

In step S12, it may be determined whether or not the period in which the engine output P becomes the rated output P2 or more continues for t1 seconds. As a result, as shown in FIG. 4, the first on-off valve 72 can be opened to reduce the output P of the engine before the output P of the engine exceeds the rated output P2 and reaches the upper limit output P1.

[Second Embodiment]
The Stirling engine 1 of the second embodiment is obtained by replacing the first on-off valve 72 of the Stirling engine 1 of the first embodiment with a proportional valve. The proportional valve is a solenoid valve whose opening degree can be continuously changed.

The control method of the Stirling engine 1 of the second embodiment will be described. FIG. 5 is a flowchart showing a procedure for controlling engine output. FIG. 6 is a graph showing an example of engine output control.

First, in step S21, the output P of the engine and the temperature Th of the heater 8 are detected. The output P of the engine is detected by the output sensor, and the temperature Th of the heater 8 is detected by the temperature sensor. The output P detected by the output sensor and the temperature Th detected by the temperature sensor are input to the control unit.

In the next step S22, the control unit determines whether or not the output P of the engine is equal to or higher than the upper limit output P1. The upper limit output P1 is set based on the rated output P2 of the engine, and is set to, for example, 105 to 110% of the rated output P2. If the engine output P is less than the upper limit output P1 (No in step S22), the process proceeds to the next step S23.

On the other hand, when the output P of the engine is equal to or higher than the upper limit output P1 (Yes in step S22), in the next step S25, the control unit instructs the proportional valve to fully open. As a result, the output P of the engine is greatly reduced, so that the Stirling engine 1 can be prevented from being damaged.

In step S23, the control unit starts controlling the opening degree of the proportional valve so that the output P becomes the rated output P2. As shown in FIG. 6, when the opening degree of the proportional valve is increased, the output P of the engine decreases, and when the opening degree of the proportional valve is decreased, the output P of the engine increases. The output P of the engine can be adjusted by opening and closing the proportional valve. By using the proportional valve, the output P of the engine can be accurately adjusted to the vicinity of the rated output P2, so that the cooling effect of the heater 8 can be maximized.

In the next step S24, the control unit determines whether or not the period in which the temperature Th of the heater 8 is equal to or higher than the allowable temperature T1 continues for t2 seconds. In step S24, when it is determined that the period in which the temperature Th of the heater 8 becomes the allowable temperature T1 or higher continues for t2 seconds (Yes in step S24), the heater 8 described later is cooled in order to suppress thermal deterioration. Perform processing. On the other hand, when it is determined that the period in which the temperature Th of the heater 8 becomes the allowable temperature T1 or more does not continue for t2 seconds (No in step S24), the process returns to step S21.

[Third Embodiment]
FIG. 7 is a schematic view showing a side cross section of the Stirling engine 1 according to the third embodiment. The Stirling engine 1 includes a second communication path 81 that communicates with the expansion space 5 of the display piston 3 and the outside, a blower 82 (corresponding to a blower) that is provided in the second communication path 81 and blows air into the expansion space 5. The second on-off valve 83 provided in the second communication path 81 on the expansion space 5 side of the blower 82, the third on-off valve 84 for switching whether or not the compression space 6 of the power piston 4 is communicated to the outside, and the blower 82. A control unit (not shown) that controls the operation of the second on-off valve 83, the opening and closing of the second on-off valve 83, and the opening and closing of the third on-off valve 84 is provided.

The control unit executes the heater cooling process when the temperature Th of the heater 8 is equal to or higher than the upper limit temperature. A method of cooling the heater 8 will be described with reference to FIG.

First, in step S31, the control unit instructs the third on-off valve 84 to open. As a result, the working gas is discharged from the compression space 6 to the outside, and the engine is stopped.

In the next step S32, the control unit determines whether or not the pressure in the compression space 6 is P0 or less. The pressure in the compression space 6 is detected by a pressure sensor (not shown), and the detected pressure is input to the control unit. Here, P0 is set to a pressure higher than the atmospheric pressure. If the pressure in the compression space 6 is P0 or less (Yes in step S32), the process proceeds to the next step S33. On the other hand, if the pressure in the compression space 6 is larger than P0 (No in step S32), the process returns to step S31.

In the next step S33, the control unit instructs the second on-off valve 83 to open. As a result, the second communication path 81 is communicated with the outside.

In the next step S34, the control unit activates the blower 82 to start the operation. As a result, the outside air is supplied to the expansion space 5, and the heater 8 communicating with the expansion space 5 is cooled. The air used for cooling the heater 8 and whose temperature has risen is cooled through the regenerator 10 and the cooler 9, and then discharged to the outside through the third on-off valve 84 provided in the compression space 6.

In step S32, the control unit may determine whether or not a predetermined time has elapsed since the third on-off valve 84 was opened. If a predetermined time has elapsed since the third on-off valve 84 was opened (Yes in step S32), the process proceeds to the next step S33, and if a predetermined time has not elapsed since the third on-off valve 84 was opened (in step S32). No), the process returns to step S31.

[Other Embodiments]
In the third embodiment described above, instead of the third on-off valve 84, a fourth on-off valve (not shown) may be provided to switch whether or not the regenerator 10 communicates with the outside. By opening the fourth on-off valve, the working gas is discharged to the outside from the working space. Further, the air used for cooling the heater 8 and whose temperature has risen is discharged to the outside from the fourth on-off valve through the regenerator 10. As a result, the air is discharged to the outside without passing through the cooler 9, so that the pressure loss can be reduced, and a large amount of outside air can be supplied to the expansion space 5 by the blower 82 to efficiently cool the heater 8.

In the above-described embodiment, the description is based on the β-type Stirling engine 1, but other types of Stirling engines such as α-type and γ-type may be used.

Although the embodiments of the present invention have been described above with reference to the drawings, it should be considered that the specific configuration is not limited to these embodiments. The scope of the present invention is shown not only by the description of the above-described embodiment but also by the scope of claims, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

1 Stirling engine 3 Displacer piston 4 Power piston 5 Expansion space 6 Compression space 8 Heater 9 Cooler 12 Crankshaft 13 Crankcase 71 1st communication path 72 1st on-off valve 73 Check valve 81 2nd communication path 82 Blower 83 2nd open / close Valve 84 3rd on-off valve

Claims (4)

Reciprocating display pistons and power pistons,
A crankshaft connected to the displacer piston and power piston,
A crankcase that supports the crankshaft and
The heating part exposed to the heat source part and
A temperature sensor that detects the temperature of the heating unit and
An output sensor that detects the output of the engine and
A first communication path communicating with the compression space of the power piston and the inside of the crankcase,
The first on-off valve provided in the first communication path and
A control unit that controls the opening and closing of the first on-off valve,
A check valve, which is provided in parallel with the first on-off valve and has a forward direction from the inside of the crankcase toward the compression space, is provided.
When the temperature of the heating unit based on the detection temperature of the temperature sensor is less than the upper limit temperature and the output based on the detection output of the output sensor is equal to or more than the upper limit output larger than the rated output, the control unit has the rated output. A Stirling engine that opens the first on-off valve until the lower limit output is smaller than the output. Reciprocating display pistons and power pistons,
A crankshaft connected to the displacer piston and power piston,
A crankcase that supports the crankshaft and
The heating part exposed to the heat source part and
A temperature sensor that detects the temperature of the heating unit and
An output sensor that detects the output of the engine and
A first communication path communicating with the compression space of the power piston and the inside of the crankcase,
The proportional valve provided in the first communication path and
A control unit that controls the opening degree of the proportional valve and
A check valve, which is provided in parallel with the proportional valve and has a forward direction from the inside of the crankcase toward the compression space, is provided.
When the temperature of the heating unit based on the detection temperature of the temperature sensor is less than the upper limit temperature and the output based on the detection output of the output sensor is less than the upper limit output larger than the rated output, the control unit becomes the rated output. A Stirling engine that controls the opening degree of the proportional valve as described above. Reciprocating display pistons and power pistons,
The heating part exposed to the heat source part and
A temperature sensor that detects the temperature of the heating unit and
A second communication path that communicates with the expansion space of the display piston and the outside,
A blower provided in the second communication path and blowing air into the expansion space,
A second on-off valve provided in the second communication path on the expansion space side of the blower, and
A third on-off valve that switches whether or not the compression space of the power piston is communicated to the outside,
A control unit for controlling the operation of the blower, the opening / closing of the second on-off valve, and the opening / closing of the third on-off valve are provided.
When the temperature of the heating unit based on the temperature detected by the temperature sensor is equal to or higher than the upper limit temperature, the control unit opens the second on-off valve and the third on-off valve until the temperature of the heating unit becomes equal to or lower than a predetermined temperature. A Stirling engine that drives a blower. The control unit opens the third on-off valve when the temperature of the heating unit based on the temperature detected by the temperature sensor is equal to or higher than the upper limit temperature, and after the pressure in the compression space becomes equal to or lower than a predetermined pressure or for a predetermined time. The Stirling engine according to claim 3, wherein after the lapse of time, the second on-off valve is opened to operate the blower.

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