JP2718147B2 - Stirling engine and output control method for stirling engine - Google Patents

Description

The present invention relates to a Stirling engine, and more particularly, to a Stirling engine using solar heat as a heat source of a heater.

(Prior Art) A Stirling engine, which is an external twisting engine, compresses a working gas enclosed in a working space at a low temperature (isothermal) while externally cooling it with a cooler, and at a high temperature (isothermal) while externally heating it with a heater. It has a basic cycle of expansion and heating and cooling of equal volume in between. Heating of the heater can use combustion heat of fuel such as gasoline or solar heat, regardless of the type of energy.

Then, conventionally, as an example of a Stirling engine using solar heat as a heat source of a heater, it is disclosed in US Pat. No. 4,457,133. In this device, working pistons are respectively arranged in a plurality of cylinders constituting the Stirling engine so as to be able to reciprocate, and an expansion space and a compression space are defined inside each cylinder. It is connected via a heater, a regenerator and a cooler. The reciprocating motion of each piston is taken out as a rotational torque from the output taking-out mechanism via a rod.

A working gas such as helium or hydrogen is sealed in a working space including at least the expansion space and the compression space, and the working gas is provided in a heater and a heat transfer tube connecting the expansion space and the heat storage device is provided. It is heated by the radiant heat of solar heat. The working space is connected to the gas reservoir via a minimum cycle pressure line having a one-way valve and a pressure increasing valve, and is connected to the gas reservoir via a maximum cycle pressure line including a one-way valve and a pressure reducing valve and a compressor. I have. Thus, the engine output increases when the average pressure in the working space is increased by opening the pressure increasing valve, and the engine output decreases when the average pressure in the operating space is decreased by opening the pressure reducing valve.

(Problem to be Solved by the Invention) In the conventional Stirling engine described above, the output control is performed as follows. That is, the working gas temperature T in the working space is determined by the solar thermal energy:
Q _in , the amount of heat transferred to the working gas: Q _out is proportional to the integral value of the difference between Q _in and Q _out , and the optimal operating temperature T _SET (determined by the capacity of the engine used, heat resistance, etc. to preserve the), when the temperature reaches T _SET, the integral value of the difference Q _in the Q _out is such that zero, that is controlled to be Q _in and Q _out.

The heat transfer amount Q _out to the pressure P and the working gas in the working gas, is proportional, relationship between Q _in and Q _out, for convenience if P = Q _out, Q _in = Q _out as a linear region can get. Here, if the output region of the Stirling engine, that is, the idle pressure (minimum pressure) and the maximum pressure are determined, the maximum and minimum values of Q _in are determined, and the operation range is determined.

Therefore, the relationship of Q _in = Q _out can be maintained by controlling the pressure against the fluctuation _in the operation range of Q _in by, so that _in the above-described conventional apparatus, Q _in The temperature of the heat transfer tube T, which changes according to the change, is detected by a temperature sensor, the difference between T and _TSET is determined, and the pressure P is increased or decreased according to the difference to keep the working gas temperature constant, thereby keeping the output constant. I have to.

However, in the above-described conventional apparatus, the heat transfer tube is directly heated by radiant heat of solar heat. As a result, the change in the solar thermal energy is random and large, so that the change in the temperature of the heat transfer tube is also random and large. Therefore, in order to keep the temperature of the heat transfer tube constant, it is necessary to quickly and subtly change the pressure of the working gas in accordance with the change of the solar thermal energy, and it becomes difficult to control the engine output and stabilize the engine output. In addition, there has been a problem that a pressure increasing valve and a pressure reducing valve which can flow a large flow rate and can finely adjust the pressure are required, and are expensive.

Therefore, an object of the present invention is to make it possible to stably maintain the engine output even when solar thermal energy changes.

[Configuration of the invention]

(Means for Solving the Problems) The technical means taken to solve the above-mentioned technical problems is that the Stirling engine is provided with a heater irradiated with solar heat, an expansion space disposed in the heater and having an expansion space. Heat transfer tube connecting the heat transfer tube and the compression space via a heat storage unit and a cooler, a partition plate disposed in the heater and defining a closed space surrounding the heat transfer tube, and filled in the closed space. In accordance with signals from the heat storage agent, temperature detection means for detecting the temperature of the heat storage agent, pressure adjustment means for adjusting the pressure of the working gas flowing through the working space from the expansion space to the compression space, and the temperature detection means. The present invention is configured to include a control unit for operating the pressure adjusting unit.

(Operation) According to this configuration, the solar heat energy heats the heat transfer tube via the heat storage agent and is stored as heat in the heat storage agent. Thereby, even if the solar heat energy changes, the temperature of the working gas flowing through the heat transfer tube can be quickly and quickly adjusted by the heat storage from the heat storage agent and the increase or decrease in the amount of heat transfer to the working gas by the action of the pressure adjusting means. It is possible to maintain a constant without any delicate operation, and to stabilize the engine output.

(Example) Hereinafter, an example of a Stirling engine according to the present invention will be described.

In FIG. 1, a Stirling engine 10 includes a housing
It has four pistons 12 (two pistons not shown) which are slidably fitted in four cylinders 11a (two cylinders not shown) which are formed in parallel with each other. Each piston 12 is connected via a rod 13 to a well-known rotary swash plate mechanism 14 which is an output take-out mechanism, and each piston 12 reciprocally slides with an adjacent piston 12 with a phase difference of 90 °. Then, the output shaft 15 is rotated to take out as an output to an AC generator 16 connected to the output shaft 15. The alternator 16 maintains the engine speed constant under all load conditions.

In each cylinder 11a, an expansion space whose volume increases or decreases due to the reciprocating sliding of the piston 12 on one end side of each piston 12
A compression space 18 is formed on the other end surface side of each piston 12 so that the volume of the expansion space 17 increases or decreases with a phase difference of 180 ° due to the reciprocal sliding of the piston 12. ing.

Each expansion space 17 is provided with a heater 19 fixed to the housing 11.
The adjacent piston on the side advanced by 90 ° through the heater tube 20, the regenerator 21 and the cooler 22, which are the heat transfer tubes of the present invention, extending into the concave portion 19b of the heater housing 19a of FIG.
Each of the twelve compression spaces 18 communicates with each other. A working gas (helium, hydrogen, etc.) is sealed in each space, and the solar heat energy reflected and condensed by the reflector 23 that tracks the sun is used as a high-temperature heat source in the heater housing 19.
The working gas is supplied to the concave portion 19b through the opening 19c through the opening 19c and heats the heater tube 20, so that the working gas flows between the expansion space 17 and the compression space 18 to generate an axial force on the piston 12. A Stirling cycle is formed. In the drawing, reference numeral 24 denotes a pipe of cooling water for exchanging heat with the working gas in the cooler 21, and the heater tube 20 is formed radially in a plan view, as is well known.

In the recess 19b of the combustor housing 19a, a closed space 26 in which the heater tube 20 is housed is defined by a transparent partition plate 25 made of a material having high thermal conductivity and high heat resistance and high corrosion resistance. The closed space 26 is filled with a heat storage agent 27 (NaCl, Li ₂ CO ₃ , MgCl ₂ or the like) using latent heat. (Note that the heat storage agent 27 preferably has high thermal conductivity and high heat resistance and corrosion resistance.) In the closed space 26, a temperature sensor 28 (thermoelectric element) for detecting the temperature of the heat storage agent 27 is also provided. ), And the temperature of the heat storage agent 27 is transmitted to the control device 30 as a signal.

The working space extending from each expansion space 17 to each compression space 18 is communicated with a gas reservoir 35 via a minimum cycle pressure line 34 having a one-way valve 32 and a switching valve 31, and
Highest cycle pressure line with one-way valve 36 and switching valve 31
It is connected to a gas reservoir 35 via 37. Switching valve 31
Is a three-port two-position solenoid-operated switching valve, which communicates the gas reservoir 35 with the highest cycle pressure line 37 and shuts off the gas reservoir 35 and the lowest cycle pressure line 34, and the gas reservoir 35 and the lowest cycle pressure line 34 Through,
The control device 30 selectively switches between the gas reservoir 35 and the second position for shutting off the highest cycle pressure line 37 according to the signal of the temperature sensor 28. In the present embodiment, a gas having a maximum pressure of the fluctuation pressure of the gas in the working space caused by the reciprocation of each piston 12 is sealed in the gas reservoir 35.

The operation of the present embodiment having the above configuration will be described with reference to the time chart shown in FIG. 3 and the flow chart shown in FIG.

Temperature T of the heat storage agent 27, solar thermal energy: Q _in, the amount of heat transferred to the working gas: When Q _out, as shown in FIG. 2, Q _in
And Q _out is proportional to the integral value. However, since the heat storage agent 27 has a melting point, the temperature does not change at this melting point, and the temperature is maintained until the heat storage agent 27 starts melting (point A) and completely melts (point B). It will be constant. During this time, the heat amount of Q _st as latent heat is accumulated in the heat storage agent 27. still,
If the temperature of the heat storage agent 27 continues to rise above the melting point (point B),
It is desirable that the temperature of the heat storage agent 27 be equal to or lower than the melting point because the heat storage agent 27 may not only boil but also cause the destruction of the partition plate 25. In addition, when the heat storage agent 27 changes phase, vacuum bubbles are generated, and when air bubbles are generated around the heater tube 20, the difference between the temperature of the heat storage agent 27 and the temperature of the heater tube 20 increases. Therefore, if the temperature of the heater tube 20 is detected by the temperature sensor, there is a possibility that the heat storage agent 27 may have a melting point or higher. Therefore, in the present invention, the temperature of the heat storage agent 27 is detected by the temperature sensor (compared to measuring the temperature of the heater tube 20, it is easy and sufficient to insert the thermocouple into the heat storage agent 27). , Heat storage agent 27
A melting point T _S of the optimal operating temperature _SET, the switching valve 31 the pressure of the working gas so as to maintain a T _S, is adjusted by the pressure adjusting means in the present invention comprising a one-way valve 32, 36 and the like. Note that the temperature of the heater tube 20 and the temperature of the heat storage agent 27 are proportional to the point A, not proportional from the point A to the point B, but proportional to the points after the point B.

In FIG. 4, at step 101, the temperature T of the heat storage agent 27 is detected by the temperature sensor 28, and the detected temperature is transmitted as a signal to the control device 30, and at step 102, the temperature T of the heat storage agent is equal to or higher than T _S ( (Point B) is determined.

Then, in step 102, “NO”, that is, the heat storage agent 27
If the temperature T is equal to or lower than the melting point T _S (point B), the flow returns to step 101, and “YES”, that is, the solar thermal energy Q
_in is irradiated to the heat storage agent 27, the temperature T of the heat storage agent 27 is the melting point T
When it is equal to or more than _S (point B), the process proceeds to step 103. still,
Until the temperature T of the heat storage agent 27 reaches the melting point T _S (point B), the switching valve 31 is kept at the first position, and the pressure P in the working space is kept at the idle pressure. Accordingly, the temperature of the heat storage agent 27 rises rapidly. At this time, the temperature T of the heat storage agent 27 is at a temperature of point A in Figure 2 is reached the melting point T _S, the pressure P is maintained in the idle pressure, increase in the Q _in the to melt the heat storage agent 27 And the temperature is kept constant.

In step 103, the output shaft 15 is driven via a starter (not shown) (which can also be started by the AC generator 16), and each piston 12 reciprocates at a predetermined phase difference by the rotary swash plate mechanism 14. Slided and solar thermal energy
By Q _in , the heater tube 20 is heated via the heat storage agent 27, the Stirling engine 10 is made to move independently, and in step 104 the switching valve 31 is switched to the second position by the control device 30, and the pressure in the working space is changed. P is the maximum pressure (pre-expected pressure value corresponding to the equivalent Q _out to the maximum value of Q _in). As a result, the heat transfer amount Q _out to the heater tube 20
There the maximum engine power is increased, if thereafter decreased solar thermal energy Q _in, that the amount of heat Q _st stored in the heat storage agent 27 is consumed to maintain the Q _out, the solar thermal energy Q _in Even if it changes, the temperature of the working gas flowing through the heater tube 20 can be kept constant without operating the pressure adjusting means quickly and finely, and the engine output is kept stable. And, even if the consumption of Q _st of solar thermal energy Q _in is also stored in the heat storage agent 27 decreased Note, Q _in
When the value decreases, the engine is stopped. That is, in step 105, it is determined whether the engine output is zero or not, and "NO"
If so, the switching valve 31 is switched to the first position in step 108, and the engine is stopped in step 109.

If “YES” is determined in step 105, the step
Proceeding to 106, it is determined whether the temperature T of the heat storage agent 27 is equal to or lower than the dangerous temperature. If "YES", the process returns to step 105, and if "NO", the process proceeds to step 107, where the opening 19c of the heater housing 19a is closed and the solar heat energy Q
abnormality processing is performed to cut off the input of the _in, step 108
, The switching valve 31 is switched to the first position, and the engine is stopped.

5 and 6 show a time chart and a flow chart according to a second embodiment of the present invention, respectively. The configuration of the second embodiment is the same as that of the embodiment shown in FIG.

In this embodiment, the pressure of the working gas in the working space is controlled in two stages, and the pressure P is set to a minimum operating pressure (corresponding to Q _in min) and a maximum operating pressure (corresponding to Q _in max).
Control.

In FIG. 5, although the temperature of the heat storage agent 27 rises as the solar thermal energy Q _in rises, the switching valve 31 is held at the first position until the temperature T of the heat storage agent 27 reaches the point B, and Is maintained at the minimum operating pressure (idle pressure). When the temperature T of the heat storage agent 27 reaches the point B (T is larger than the melting point T _S ), the switching valve 31 is switched to the second position, and the pressure P in the working space is set to the maximum pressure (the same as in the first embodiment). Maximize Q _out . Thereafter, when Q _in decreases and the amount of heat Q _st stored in the heat storage agent 27 is consumed, that is, when the temperature T of the heat storage agent 27 reaches the point A (T is smaller than the melting point T _S ),
The switching valve 31 is set to the first position, and the working gas pressure is switched to the minimum operating pressure. This reduces the amount of Q _out ,
Heat is stored in the heat storage agent 27. Then, the temperature T of the heat storage agent 27
Reaches the point B (T is larger than the melting point T _S ), the switching valve 31 is switched to the second position again, and the pressure P in the working space is set to the maximum pressure and the pressure of the working gas is set to the maximum Q _out. Maximize P to get high engine output.

The control flow is as shown in FIG.
At 201, the temperature of the heat storage agent 27 is read by the temperature sensor 28, and at step 202, the temperature T of the heat storage agent 27 is compared with the melting point T _{S. When} the temperature T is T _S , the process goes to step 201,
When the temperature T is higher than T _S (point B or higher),
Proceeding to 203, the switching valve 31 is switched to the second position. If the temperature T is equal to or less than T _S (the point A or less) in step 202,
Proceeding to step 204, the switching valve 31 is switched to the first position.

Therefore, in this embodiment, the pressure control is controlled in two stages by using the heat quantity _Qst stored in the heat storage agent 27, and the engine output is made constant by the heat storage effect of the heat storage agent 27. In addition, the two-stage switching frequency can be reduced. In this embodiment, the Stirling engine 10 is started during the process until the temperature T of the heat storage agent 27 reaches the point A, and the pressure P of the working gas reaches the point B when the temperature T of the heat storage agent 27 reaches the point B. until it is maintained in an idle pressure, thereby the temperature T of the heat storage agent 27 increases, Q _st of the heat storage agent 27 is accumulated.

In the two embodiments described above, the solar thermal energy
In an environment where Q _in is constant (space, desert, etc.), control is simple and effective.

FIG. 7 shows a third embodiment of the present invention. In this embodiment, unlike each of the above-described embodiments, a pressure increasing valve 38 is interposed in the lowest cycle pressure line 34, and a pressure reducing valve 39 is interposed in the highest cycle pressure line 37.
38,39 are operable independently. Also, pressure reducing valve 3
A compressor 40 is interposed between 9 and the gas reservoir 35,
In addition, a pressure sensor 41 is provided in a pipeline extending from the working space to each of the one-way valves 32 and 36, and a signal from the pressure sensor 41 is transmitted to the control device 30.

Further, the reflector 23 is installed emitted calorimeter 42 for detecting the solar thermal energy Q _IN emitted into reflector 23, the radiation heat quantity meter 42 signals are summer to be transmitted to the controller 30 . In FIG. 7, the same components as those in the embodiment shown in FIG. 1 are denoted by the same reference numerals as those used in FIG.

In this embodiment, the pressure control is performed more finely, and the pressure value used at this time is Q _in = Q as shown in FIG.
_out instead of using the pressure value
Only large pressure (Q _out> Q _in consisting of pressure), ΔP only use a small pressure (Q _out> Q _in consisting of pressure).

In FIG. 9, the working gas pressure P is set to an idle value, and the temperature T of the heat storage agent 27 reaches the point B (T>
Hold this until T _s ). When the temperature of the heat storage agent 27 reaches the point B (T> T _S ), the working gas pressure P is changed to Q at that point.
_The pressure is set to ΔP higher than the pressure at which _in = Q _out . Accordance connexion, because the amount of heat transferred to the working gas serving as the _{Q out + Q st (1)} , ΔQ than heat Q _st stored in the heat storage agent 27
By replenishing _st (1), the temperature changes from point B to point A (the temperature is constant). However, since Q _in further rises, this Q _st (1) is _eventually recovered by Q _in , and the temperature T of the heat storage agent 27 reaches the point B again. Therefore, the next step is to set a pressure ΔP larger than the pressure equivalent to Q _in at this point. Thereafter, each time the temperature T of the heat storage agent 27 returns to the point B again, the control for increasing the pressure P by ΔP is repeated.

When the rise of Q _in stops (assuming that it becomes constant), the amount of heat (Q _out + Q _st (0)) taken by increasing the pressure P by ΔP is higher than that of Q _in which supplies the heat storage agent 27 with heat. Also increases. Then, the temperature T of the heat storage agent 27 cannot return to the point B, and reaches the point A. In this case, the working gas pressure is set to a pressure lower by ΔP. As a result, the amount of heat transfer to the working gas becomes Q _in -Q _st (0),
The heat is stored in the heat storage agent 27 again. This heat storage is Q
_{When st} (0) is reached, the temperature T of the heat storage agent 27 reaches the point B again, and then the working gas pressure P is set to a pressure higher by ΔP. Thereafter, if Q _in is constant, a pressure that is larger and smaller by ΔP than a pressure P corresponding to Q _in is repeated. At this time, when Q _in = constant, the output of ΔP is also constant.

Next, when Q _in decreases, the working gas pressure P is increased by P-Δ
Even as P, the temperature T of the heat storage agent 27 cannot return to the point B,
It will be point A. In this case, the working gas pressure is set to a pressure ΔP smaller than the pressure P corresponding to Q _in at that time. If the working gas temperature T still cannot return to the point B, the pressure value is further reduced by ΔP.

 The above control is shown in FIG.

In FIG. 10, in step 301, the temperature T of the heat storage agent 27 is set.
Is read, and the temperature T and T _S are compared in step 302,
If T <T _S (point A), the process returns to step 301, and T = T _S (A
If so, the process proceeds to step 303. In step 303, the engine is started, and the working gas pressure P in the working space is set to the idle pressure. (Open the pressure reducing valve 39) Next, step 304
To read the temperature T of the heat storage agent 27 again, and
At 5, the temperature T of the heat storage agent is determined. Here, the temperature T = T
_{If S} (points A and B), return to step 304, where temperature T> T _S
(B point), then the process proceeds to step 306, at step 306, the amount of heat radiated meter 42 installed in the reflector 23 reads the amount of heat radiated (solar thermal energy Q _in), to the amount of heat radiated by step 307 (Q _in) computed by the working gas pressure Pb (ideal pressure) control device 30 to Q _in = Q _out against. Next, at step 309, the target pressure Pset is _set by Pb + ΔP, at step 309 the pressure increasing valve 38 is opened, and at step 310 the working gas pressure P is read by the pressure sensor 41. Compared to the P _set the loaded P at step 311, P is P _set
If so, the flow proceeds to step 312, closes the pressure increasing valve 38, proceeds to A, and proceeds to step 304. P at step 311
If is not _{equal to} or greater than Pset, the process returns to step 309.

If the temperature T <T _S (point A) at step 305, the process proceeds to step 313, where the radiant calorimeter 42 installed on the reflector 23 is set.
To read the radiant heat (solar thermal energy Q _in )
In step 314, Q _in = Q _out for the radiant heat (Q _in )
The working gas pressure Pb (ideal pressure) is calculated by the controller 30. Next, at step 315, the target pressure Pset is _set to Pb−
At step 309, the pressure reducing valve 38 is opened, and at step 316, the working gas pressure P is read by the pressure sensor 41. The read P is _set at step 317
Compared to, Tara P is decreased to less P _{The set,} the process proceeds to step 319, it opens the pressure reducing valve 38, the flow proceeds to step 304 proceeds to A. At step 318, if P is not less than _Pset ,
Return to step 316.

As described above, in the present embodiment, Q is determined by determining whether the temperature of the heat storage agent 27 is at the point A or the point B.
analogy changes direction _in, when Q _in is in the increasing direction, as large as possible amount of excisional and Q _out to increase the pressure and excisional to lower the pressure when the reverse to Q _in is in the decreasing direction Thereby, the recovery of the heat storage amount of the heat storage agent 27 is hastened.

In a conventional Stirling engine, in order to obtain the maximum efficiency, the purpose is to maintain the working gas temperature at a temperature at which the maximum efficiency is obtained, and in order to keep the working gas temperature constant, the amount of Q _out , that is, Controls the working gas pressure. However, since the working gas pressure and the engine output are in a substantially proportional relationship, the engine output changes according to the change _in Qin. On the other hand, in the present embodiment, the temperature T of the heat storage agent 27 is A
Active control is performed so as to fluctuate between the point and the point B. As described above, since the temperature T of the heat storage agent 27 and the temperature of the heater tube 20 are not in a proportional relationship between the points A and B, changing the temperature between them keeps the temperature of the heater tube 20 constant. Make it impossible. That is, when the pressure is set higher by ΔP to control from point B to point A, as the temperature of the heat storage agent 27 approaches the point A, the temperature of the heater tube 20 drops significantly. Engine power decreases. However, according to the present embodiment, _in response to the fine fluctuation of Qin, the pressure is positively fluctuated, so that the cycle of the fluctuation of the engine output is larger than that of the above-described conventional Stirling engine as shown in FIG. It can be increased (lengthened), and the engine output can be stabilized against a change _in Q _in .

〔The invention's effect〕

As described above, according to the present invention, solar thermal energy heats the heat transfer tube via the heat storage agent and is stored in the heat storage agent as heat storage by latent heat. Thereby, even if the solar thermal energy changes, the heat storage from the heat storage agent and the increase or decrease in the amount of heat transfer to the working gas by the action of the pressure adjusting means,
The temperature of the working gas flowing in the heat transfer tube can be kept constant without operating the pressure adjusting means quickly and finely, and the engine output can be stabilized.

Further, according to the present invention, unlike the related art, there is no need for pressure adjusting means capable of flowing a large flow rate and fine pressure adjusting means, so that the cost of the Stirling engine can be reduced.

Further, according to the present invention, the heat transfer tube is not locally heated by the heat storage agent, the temperature distribution thereof can be made uniform, and the durability of the heat transfer tube can be improved.

[Brief description of the drawings]

Sectional view showing an embodiment of FIG. 1 is従Tsuta Stirling engine of the present invention, FIG. 2 and the temperature of the heat storage agent in the present invention, the integral value of the difference between the heat transfer amount Q _out of the solar thermal energy Q _in the working gas FIG. 3 is a time chart of the first embodiment, FIG. 4 is a flow chart of the first embodiment, FIG. 5 is a time chart of the second embodiment, FIG. Is a flow chart of the second embodiment, FIG. 7 is a sectional view of the third embodiment, and FIG. 8 is solar thermal energy in the third embodiment.
FIG. 9 is a time chart of the third embodiment, and FIG. 10 is a flow chart of the third embodiment, showing a relationship between Q _in and the working gas pressure P (∽heat transfer amount Q _out to the working gas). FIG. 11 is a detailed view of FIG. 10 ... Stirling engine, 11 ... housing, 12 ... piston, 14 ... rotary swash plate mechanism, 15 ... output shaft, 16 ... AC generator, 17 ... expansion space, 18 ... compression space, 19 ... heater, 19a ... heater housing, 19b ... recess, 19c ...
... opening, 20 ... heater tube (heat transfer tube), 21 ... heat accumulator, 22 ... cooler, 23 ... reflector, 25 ... partition plate, 26 ... closed space, 27 ... heat storage agent, 28 ... ... Temperature sensor (temperature detection means), 30 ... Control device (control means), 31 ...
... switching valve (pressure adjusting means), 32 ... one-way valve, 34 ... lowest cycle pressure line, 35 ... gas reservoir (working gas supply source), 36 ... one-way valve, 37 ... highest cycle pressure line, 38 pressure booster valve (pressure adjusting means), 39 pressure reducing valve (pressure adjusting means), 40 compressor, 41 pressure sensor (pressure detecting means), 42 radiant calorimeter (radiant heat detecting means) ).

Claims (13)

(57) [Claims] 1. A heater to be irradiated with solar thermal energy, a heat transfer tube disposed in the heater and connecting an expansion space and a compression space via a heat storage device and a cooler, and disposed in the heater. A partition plate defining a closed space surrounding the heat transfer tube, a heat storage agent filled in the closed space, temperature detecting means for detecting a temperature of the heat storage agent, an operation from the expansion space to the compression space. A Stirling engine comprising: a pressure adjusting means for adjusting the pressure of a working gas flowing through a space; and a control means for operating the pressure adjusting means in response to a signal from the temperature detecting means. 2. The pressure adjusting means includes a minimum cycle pressure line having a one-way valve that allows only the flow of the working gas to the working space, and a one-way valve that blocks the flow of the working gas to the working space. A working gas supply source communicating with the working space via the highest cycle pressure line, and a working gas supply source interposed between the working gas supply source and the two lines to communicate the working gas supply source with the highest cycle pressure line. A first position for shutting off the working gas supply source and the lowest cycle pressure line, a communication between the working gas supply source and the lowest cycle pressure line, and the working gas supply source and the highest cycle pressure line And cut off the second
The Stirling engine according to claim 1, further comprising a switching valve that can be selectively switched between a position and a position by the control means. 3. The control means holds the switching valve in a first position until the temperature of the heat storage agent reaches the melting point or higher, and moves the switching valve to the second position when the temperature of the heat storage agent is higher than the melting point. The Stirling engine according to claim 2, wherein the switching is performed. 4. The control means holds the switching valve in the first position until the temperature of the heat storage agent reaches the melting point or higher, and switches the switching valve to the second position when the temperature of the heat storage agent is higher than the melting point. The Stirling engine according to claim 2, wherein the switching valve is switched to a position, and when the temperature of the heat storage agent is equal to or lower than the melting point, the switching valve is switched to the first position to maintain the temperature of the heat storage agent at the melting point. . 5. A radiant heat detecting means for detecting solar heat energy irradiating a heater, and a pressure detecting means for detecting a pressure of a working gas in the working space, wherein the control means detects the temperature of the working gas from the temperature detecting means. A target pressure value is set according to a signal and a signal from the radiant heat amount detecting means, and the pressure adjusting means is operated so that the pressure in the working space becomes the target pressure value. The Stirling engine according to item (1). 6. The pressure adjusting means includes a minimum cycle pressure line having a one-way valve that allows only the flow of the working gas to the working space, and a one-way valve that blocks the flow of the working gas to the working space. A working gas supply source that communicates with the working space through each of the highest cycle pressure lines, a pressure increasing valve disposed in the lowest cycle pressure line, and a pressure reducing valve disposed in the highest cycle pressure line. The Stirling engine according to claim 5, wherein the Stirling engine comprises: 7. The control means compares the temperature detected by the temperature detection means with the melting point of the heat storage agent, and calculates an ideal pressure value of the working gas corresponding to the radiant heat detected by the radiant heat detection means. Calculate, when higher than the melting point, control the opening and closing of the pressure increasing valve and the pressure reducing valve so as to be a predetermined amount higher than the ideal pressure, when lower than the melting point, to a pressure lower than the ideal pressure by a predetermined amount The Stirling engine according to claim (6), wherein opening and closing of the pressure increasing valve and the pressure reducing valve are controlled so as to be as follows. 8. The Stirling engine according to claim 7, wherein the control means operates the pressure increasing valve and the pressure reducing valve so as to maintain the temperature of the heat storage agent at a melting point. 9. A minimum cycle pressure line having a valve means and a one-way valve allowing only the flow of the working gas to the working space, and a one-way valve for blocking the flow of the working gas to the valve means and the working space. The working space is communicated with a working gas supply via a maximum cycle pressure line having the following, and the working space is communicated through a heat transfer tube disposed in a cooler, a heat storage device and a heater, and the heat transfer tube is connected to the working space. A Stirling engine heated by solar thermal energy, wherein a heat storage agent is filled in a closed space defined by a partition plate so as to surround the heat transfer tube in the heater, and the temperature of the heat storage agent is set to a temperature. The control means controls the opening and closing of the valve means in accordance with the temperature detected by the temperature detection means, and controls the opening and closing of the Stirling engine to maintain the temperature of the working gas in the heat transfer tube constant. Control method. 10. A first valve means for communicating between the working gas supply source and the highest cycle pressure line and shutting off the working gas supply source and the lowest cycle pressure line.
A switching valve for selectively switching a position and a second position for communicating the working gas supply source with the lowest cycle pressure line and for shutting off the working gas supply source and the highest cycle pressure line by the control means; The control means compares the temperature detected by the temperature detecting means with the melting point of the heat storage agent, and switches the switching valve to the second position when the temperature is higher than the melting point. The output control method for a Stirling engine according to claim (9), wherein the temperature of the working gas in the heat transfer tube is maintained constant. 11. A first valve means for communicating between the working gas supply source and the highest cycle pressure line and shutting off the working gas supply source and the lowest cycle pressure line.
A switching valve for selectively switching a position and a second position for communicating the working gas supply source with the lowest cycle pressure line and for shutting off the working gas supply source and the highest cycle pressure line by the control means; The control means compares the temperature detected by the temperature detecting means with the melting point of the heat storage agent, and switches the switching valve to the second position when the temperature is higher than the melting point, and switches the switching valve to the first position when the temperature is lower than the melting point. The output control method for a Stirling engine according to claim 9, wherein the temperature of the working gas in the heat transfer tube is maintained constant by switching to a position to maintain the temperature of the heat storage agent at the melting point. . 12. A minimum cycle pressure line having a pressure increasing valve and a one-way valve allowing only the flow of the working gas to the working space, and a pressure reducing valve and a one-way valve for blocking the flow of the working gas to the working space. The working space communicates with a working gas supply source through a maximum cycle pressure line having a maximum cycle pressure line, the working space communicates with a heat transfer tube disposed in a cooler, a heat storage device and a heater, and the heat transfer tube is connected to a solar heat source. A Stirling engine heated by energy, wherein a heat storage agent is filled in a closed space defined by a partition plate so as to surround the heat transfer tube, and the temperature of the heat storage agent is detected. Means, the radiant heat of the solar thermal energy is detected by radiant heat detection means, the pressure of the working gas in the working space is detected by pressure detection means, and the temperature detection is performed by the control means. Setting a target pressure value in accordance with a signal from a stage and a signal from the radiant heat amount detection means, and controlling opening and closing of the pressure increasing valve and the pressure reducing valve so that the pressure in the working space becomes the target pressure value. An output control method for a Stirling engine. 13. The control means compares the temperature detected by the temperature detection means with the melting point of the heat storage agent and calculates an ideal pressure value of the working gas in accordance with the radiant heat detected by the radiant heat detection means. When the temperature is higher than the melting point, the opening and closing of the pressure-increasing valve and the pressure-reducing valve are controlled so that the pressure becomes higher by a predetermined amount than the ideal pressure, and when the temperature is lower than the melting point, the pressure becomes lower by a predetermined amount than the ideal pressure. The output control method for a Stirling engine according to claim 12, wherein opening and closing of the pressure increasing valve and the pressure reducing valve are controlled.