JPS5851251A - Stirling cycle engine - Google Patents

Abstract

PURPOSE:To smooth the timely fluctuation of the amount of heat transmission by a method wherein a regenerator is provided with a heat accumulating function in case the Stirling engine is constituted by employing large and small rotary piston engines, different in the volume of the operating chambres thereof, and adding a cooler, a regenerator and the like thereto. CONSTITUTION:Large high temperature and low temperature operating engines 1, 2 and the small low temperature and high temperature operating engines 3, 4 are constituted by employing single node peritrocoid rotary piston engines having two operating chambers and the rotors 1c-4c of each engines 1-4 are rotated cooperatingly. A high temperature operating fluid in the operating chamber 1a of the engine 1 is discharged into the regenerator 5 having the heat accumulating function while a low temperature operating fluid in the operating chamber 3b of the engine 3 is discharge into the regenerator 5 in the same manner. The operating fluid in the operating chamber 2a of the engine 2 is introduced into the operating chamber 3b of the engine 3 through the cooler 6 while the operating fluid in the operating chamber 4a of the engine 4 is introduced into the operating chamber 1b through a heater 7. According to this method, the desired Stirling engine may be constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel Stirling engine that uses a rotary piston engine formed by a single bar peritrochoid to extract power without forming a Stirling cycle with an extremely simple mechanism. It is something.

An external heat engine called a Stirling engine performs a Stirling cycle consisting of isothermal compression, isovolume heating, isothermal expansion, and isovolume cooling, and its thermal efficiency is equal to that of the Carnot cycle, making it the highest thermal efficiency among heat engines. be. Since there is a wide range of available heat sources and any type of heat source can be used, the energy saving effect of using this engine is extremely large in today's world where saving energy is an important issue. This engine is also known as an excellent heat engine with very little vibration and noise, and with little harmful components in the exhaust gas.

Furthermore, the Stirling cycle is reversible, and if the engine is driven by external power, it can be used as a heat pump or as a refrigeration cycle.

Although the Stirling engine is theoretically excellent, it is difficult to put it into practical use because it requires a complicated mechanism to run the Stirling cycle.
However, it has not yet become widely disseminated.

This is because the Stirling engine as conventionally considered had various problems as follows.

An example of a conventional Stirling engine is a system in which a piston and a displacer are combined to perform a Stirling cycle. The movement of the piston and displacer must be complicated, and a simple crank mechanism cannot produce the output. For this reason, a rhombic drive system or the like is employed, but the movement is a distorted waveform, and the drive mechanism is complex, resulting in a large device 5- and a large power loss.

Another method is to operate four sets of pistons with their phases shifted by 90 degrees from each other, and perform a Stirling cycle between the twinkling pistons, and the reciprocating movement of each piston is converted into rotational motion by a swash plate and output. Is there a way to take it out from the shaft? Even with this method, the mechanism that converts reciprocating motion to interlocking rotation is complicated, and its operation is not smooth.
Further, since thrust is generated on the output shaft, a thrust bearing or the like is required, resulting in a large loss of mechanical energy.

All of these lines use a heat storage type regenerator, but since working fluids at both extremes of temperature and high temperature frequently enter and exit the regenerator, there is a problem of thermal fatigue, and it is difficult to find materials that can be used. This is the current situation.

Also, sealing to prevent leakage of working fluid is a difficult problem. Helium is the working fluid for the Stirling engine.
In order to enclose light gas such as hydrogen at high pressure, there is a secondary fi from around the displacer shaft, piston, and piston rod! ＞'The current situation is that we are struggling to take countermeasures. A roll sock seal nut has been considered as one of the countermeasures against this problem, but it cannot withstand long-term use.

Since the conventional Stirling engine has various problems as described above, various improvements have been devised. For example, in JP-A No. 11sa-134136, one or more pairs of large and small cylinders are combined, and a working fluid circulation path connecting these to a heater, a cooler, and a regenerator is set up for each stroke of each piston. A method has been proposed in which a Stirling cycle is formed by opening and closing valves in the circulation path.

Although this method certainly alleviates the conventional drawbacks to some extent, it has many other problems as pointed out below, and is by no means satisfactory.

First, it is necessary to provide a large number of on-off valves and check valves in the working fluid circulation path, making the shape of the circulation path larger and more complicated. Connecting the cylinders via the crankshaft requires a different method for the crank part, so it is difficult to create a casing with an integrated structure like in a normal multi-cylinder internal combustion engine, and it is difficult to connect the cylinders through the crankshaft. It is still difficult to improve the sealing of the working fluid, especially in parts such as piston ronds, where lateral force is applied in addition to reciprocating motion, by using high-temperature, high-pressure gas. There are problems such as the fact that it is extremely difficult to seal against.

The present inventors have invented a new Stirling engine that solves these problems using a completely new mechanism, and have already proposed it in Japanese Patent Application No. 56-105208.56-1.18011.

However, although this invention solves most of the drawbacks of the conventional Stirling engine, the amount of high-temperature working fluid flowing into the heat exchanger type regenerator and the amount of low-temperature working fluid are It is not constant every second, but depending on the rotational position of the rotor of the working engine, there are times when a large amount of high-temperature working fluid flows into the regenerator and times when a large amount of low-temperature working fluid flows into the regenerator.

This point will be described in some detail with reference to FIG. Figure 1 shows an example of a new Stirling cycle engine according to Japanese Patent Application No. 56-105'208. In the figure, (1) is a large high temperature operating engine, (2) is a large low temperature operating engine, and (3) is a small low temperature operating engine. The operating engine (4) is a small high-temperature operating engine, and both engines utilize a single-section belitrochoid rotary piston engine with two working chambers. One of the two working chambers of each engine is indicated by the suffix a, and the other is indicated by the suffix C. 5 is a regenerator, 6 is a cooler, and 7 is a heater, and these and each engine are connected by fluid passages 8, 9, 10', and 11 as shown in the figure. Cooler 6
A cold heat source 12 is supplied to the heater 7, and a high heat source 13 is supplied to the heater 7.

To explain the operation of the regenerator in detail, first, the rotors of engines (1), (2), (3), and (4) are interlocked and rotate synchronously. The high-temperature working fluid in the working chamber la of the engine (1) is discharged by the rotation of the rotor and flows into the regenerator 5. On the other hand, the low-temperature working fluid in the working chamber 3b of the engine (3) also flows into the regenerator 5. The two working fluids exchange heat, and the working fluid from the working chamber 1a of engine 1 (1) flows into
It is cooled and moved to the working chamber 2bK of the engine (2), and the engine (
The working fluid in the working chamber 3a of the engine (4) is heated and
) to the working chamber 4b. However, according to the principle of the Stirling cycle engine, while the rotor moves from dead center to dead center, the total number of moles of the working fluid on the high temperature side and the low temperature side passing through the regenerator is equal, but during the rotation of the rotor, In this case, the number of moles of both working fluids flowing into the regenerator is not necessarily equal, and a phenomenon is observed in which the working fluid on the high temperature side moves more.

The reason is that the working fluid in the large low-temperature working chamber la is cooled by the regenerator, its volume is reduced, and it flows into the large low-temperature working chamber 2b, and both working chambers are at a common pressure F, so the working fluid in the large low-temperature working chamber 1a is More working fluid always moves from 1a to 2b than the rate of change in volume, while the working fluid in the small low-temperature working chamber 3a is heated by the regenerator, increases in volume, and flows into the working chamber 4b. - Therefore, the movement of the working fluid always occurs by a smaller amount than the rate of change in the volume of the working chamber 3a.

For this reason, the regenerator does not recover 100% of the heat, which reduces the efficiency of the Stirling cycle engine.

The inventors of the present invention have researched various ways to prevent such phenomena and increase the efficiency of Stirling cycle engines, and have found the following excellent improvement method.

First of all, the regenerator rC is equipped with a heat storage function.
This is a method for smoothing temporal fluctuations in the amount of heat transfer caused by an imbalance in the amount of working fluid flowing in on the high temperature side and the low temperature side.

As a preferred embodiment of a regenerator having a heat storage function for this purpose, the one shown in FIG. 2 or FIG. 5 (the effect is excellent). The regenerator casing 21 is a heat storage wall, 22 is a heat transfer wall, 23
24 indicates a fin for increasing the heat transfer effect of the heat storage wall; 24 indicates a heat storage material filled in the heat storage wall; 25I'i seals between the heat transfer wall and the heat storage wall; 27 indicates the flow of working fluid; Show the path. The details of the structure are as shown in the enlarged part of Figure 2, by bending metal plates etc.
The parts are assembled by JI work and overlapping, and the sealing part is welded, pressure welded, or by twisting and tightening the sealing material. As a heat storage material, it is filled with a material that has good thermal conductivity and a large specific heat,
Metals, inorganic salts of non-metallic elements, ceramics, glass, etc. can be used, and they can be molded into a plate shape and inserted, or they can be designed to improve heat transfer. However, when used as a vertical type, it is more efficient to provide a partition plate or the like inside the heat storage section to limit convection. As shown in FIG. 3, it is highly effective to fill the heat storage material in the fin portions as well.

The high-temperature side working fluid and the low-temperature side working fluid are arranged alternately so that the same type of working fluids flow in adjacent channels in a regenerator with a structure such that a force of 1 is applied, for example, so that the low-temperature side working fluids do not flow next to each other. (hereinafter referred to as mixed flow), the two flow in countercurrent directions to each other. That is, in FIG. 2, for example, the distribution is such that the high-temperature side working fluid flows through the flow passages marked with diagonal lines, and the low-temperature side working fluid flows through the other passages. As for the structure of the inlet and outlet of the working fluid, for example, in the case of the regenerator shown in FIG. 2, as shown in FIG. 4, a mountain-shaped heat transfer wall 22 (indicated by 22 in FIG. At both ends of the inlet or outlet of the regenerator, there is a heat storage wall 21, which is a flat plate as shown in 28.
After the walls are made parallel to each other, each working fluid can be taken out from the side as shown in FIG.

FIG. 5 shows another embodiment of the regenerator of the present invention, which can exhibit similar effects. In the figure, 31 is a regenerator casing, 32 is a heat storage wall, 33 is a heat transfer wall, 34 is a fin, 35 is a heat storage material, 36 is a sealing material 1, 37, 38 is a working fluid flow path. As is clear from the figure, this embodiment also has a fluid flow path configured by a heat transfer wall and a heat storage wall equipped with fins, and allows the working fluid to flow in parallel and countercurrent flow. A regenerator with this function is one of the main features of the present invention.

As already mentioned, the regenerator of the present invention can be manufactured at low cost by combining bent metal molded plates, but the material does not necessarily have to be metal; it can also be made of ceramic or other materials. , 2 and 5, and by assembling them, exactly the same effect can be obtained.

In general, the structure of the regenerator of the present invention in which a flow path is formed by a heat transfer wall and a heat storage wall can be used not only for a regenerator but also for a cooler and a JJO heater, and such a structure By adopting this, it is possible to increase heat transfer efficiency and demonstrate stable heat exchange performance.

In addition, the material of the regenerator of the present invention does not cause high and low temperature fluids to enter and exit alternately, unlike the regenerator of conventional Stirling cycle engines, so there is little thermal fatigue, and various ordinary heat-resistant materials can be used. and can withstand long-term use.

=14- Next, the second measure, which is a feature of the present invention, is a method of increasing the heat regeneration efficiency of the regenerator by shifting the rotational phase of each rotor of the small working engine and the large working engine.

FIG. 6 is an example of a strategy in which the force is 1.

In Figure 6, 0υ is a large low-temperature operating engine, ha is a small low-temperature operating engine, 04 is a small high-temperature operating engine, 0 is a large high-temperature operating engine, 45 is a cooler, 46 is a regenerator, and 47 is a heater. , each engine and each heat exchanger have fluid flow paths 48 and 49 as shown in the figure.
．． Tie at 50.51. In each engine, the subscript a indicates one working chamber, b indicates the remaining working chamber, and C indicates the rotor. The rotors of each engine are rotated synchronously, but the rotors of the two large working engines are in the same phase, whereas the rotors of the two small working engines are rotated with a phase slightly ahead. A check valve 52 is provided between the large low-temperature working engine and the small working engine to prevent backflow of the working fluid, and between the small high-temperature working chamber and the large high-temperature working chamber, the working fluid is temporarily Throttle or beam mint valve for preventing flow of flow - 15 To explain uniformity, first of all, the horizontal axis in Fig. 7 indicates the rotation angle of the rotor from 00 degrees to 180 degrees, which corresponds to the working chamber of each engine. The rotor rotates from dead center to dead center. The vertical axis shows the change in the working chamber volume of each engine and the change in the flow rate of the working fluid on the high temperature side and low temperature side flowing into the regenerator, and 61 in the figure is the volume of the working chamber 44a of the large high temperature working engine @ The rate change 62 indicates the volume change of the working chamber 4 w b of the large low temperature operating engine v, and the sum of both volumes is always constant. 6
3 is the volume change of the working chamber 42a when the rotor 420 of the small low-temperature working engine 04 is in the same phase as the large working engine (4υ, @small), and 64 is the working chamber 43b when the small high-temperature working engine 1 East is also in the same phase. shows a change in volume of both working chambers 42a, 43b.
It is also true that the sum of the volumes of is constant. 65 indicates the change in molar flow rate of the working fluid flowing from the large high-temperature working chamber to the large low-temperature working chamber, that is, passing through the regenerator, and 66 indicates the change in the molar flow rate of the working fluid flowing from the small low-temperature working chamber to the small high-temperature working chamber. Indicates the rate of movement of working fluid into the chamber. However, the situation shown in Figure 7 shows one modeled example, and the volume ratio of the large working chamber and small working chamber changes depending on the design of the engine, and the transfer rate also depends on the heat transfer characteristics of the regenerator. , engine pressure, rotation speed, etc., and is not fixed to the example shown in FIG. 7.

Now, from Fig. 7, when the rotational phases of the rotors of the large working engine and the small working engine are equal, there is a large imbalance between the movement rate of the working fluid on the high temperature side and the movement rate of the working fluid on the low temperature side. Therefore, there is a large surplus or deficiency in the amount of heat exchanged, and in the first half of the rotation of the rotor from dead center to dead center, the working fluid on the high temperature side is not cooled sufficiently, and in the second half, the working fluid on the low temperature side is not cooled enough. It is clear that the fluid force f does not heat up enough.

However, as shown in Figure 6, by advancing the rotational phase of the rotors of the two small-operating engines relative to the rotors of the two large-operating engines, this large excess or deficiency in the amount of heat exchanged can be greatly reduced. 17- The so-called heat regeneration efficiency can be greatly improved.

To explain this using Fig. 7, if the phase of rotation of the rotor of the large working engine is delayed by about S degrees as shown in the figure, (
In other words, if the rotation phase of the rotor of a small working engine is reversed and advanced by 8 degrees, the volume change of the large high temperature working chamber and large low temperature working chamber is shown by the dotted line at 67.68, and the movement rate of the working fluid is 6
The value is shown by the dotted line at 9. Thus a great working engine,
When there is no phase difference in the rotation of the rotor of a small working engine, the difference in the movement rate of the working fluid on the high temperature side and the low temperature side is large as shown in the area A in Fig. 7, but Figure 6
In the case shown by the dotted line No. 9, the difference is slightly reduced to a small difference shown in the H region, and the heat regeneration efficiency is greatly improved. This is the second major feature of the present invention, and by using a heat storage type regenerator as the first feature already mentioned, it is possible to achieve a heat regeneration efficiency of nearly 100%. I can do it.

18- Here, the angle of inclination (or lag angle) of the rotational phase of the rotor of the large-operating engine and the small-operating engine varies depending on the design conditions of the Stirling cycle and the heat transfer dynamic characteristics of the regenerator. Furthermore, the influence of the temperature difference between the high-temperature side fluid and the low-temperature side fluid is also large, and when this temperature difference is large, it is necessary to increase the advance angle, and other factors can also be taken into account to determine the best point. In normal cases, this lead angle is 0~90°
in particular between 20° and 60° in most cases, and between 2 and 60°.
It is possible to easily find the best score after three trials.

Next, if there is a phase difference between the rotations of the rotors of the large and small operating engines, when the working fluid moves from the large, low-temperature operating engine to the small, low-temperature operating engine, the rotor of the large, low-temperature operating engine will reach the dead center. When the new low-temperature working fluid is about to be discharged from the next large low-temperature working chamber, the rotor of the small low-temperature working engine has not yet reached its dead center, so the operating fluid in the small low-temperature working chamber is under high pressure. Fluid flows backwards. In order to prevent this, as already mentioned in the explanation of the outline-19- of Fig. 6, it is necessary to
A valve 52 is provided in reverse f.

In addition, between the small high-temperature operating engine and the large high-temperature operating engine, when the rotor of the small high-temperature operating engine reaches the dead center, the rotor of the large high-temperature operating engine has not yet reached the dead center, so the high-pressure operating A small high-temperature working chamber filled with fluid is connected to a large high-temperature working chamber through a heater, and a large amount of working fluid temporarily passes through the heater, reducing Buddhist efficiency if the capacity of the heater is small. I let it go low. To prevent this, a limit valve or throttle is provided to limit the flow rate, as shown at 53 in FIG.

In FIG. 6, the cooler 45 and the heater 47 are also heat exchangers, and the working fluid flowing into them changes periodically in a sinusoidal manner, while the heat source 55 and the cold source 54 also change in type. Therefore, by using a regenerative heat exchanger for both of them, the efficiency of the heat exchanger can be increased and the size can be reduced.

As is clear from the following, the present invention completely eliminates the drawbacks of the conventional technology by using a new regenerative heat exchanger and by advancing the phase of rotation of the rotor of a small working engine relative to a large working engine. This enabled a new Stirling cycle engine to solve the problem.

It is a conceptual diagram of a Stirling cycle engine.

FIG. 2 shows the structure of a regenerative heat exchanger which is an embodiment of the present invention.

FIG. 3 shows an example of the structure of the heat transfer fins of the regenerative heat exchanger shown in FIG. 2.

FIG. 4 shows a method for supplying and extracting working fluid from the regenerative heat exchanger shown in FIG. 2.

FIG. 5 shows the structure of another embodiment of the regenerative heat exchanger.

FIG. 6 is an explanatory diagram of a Stirling cycle engine in which the phase of rotation of the rotor of a small working engine is advanced compared to the large working engine of the present invention.

FIG. 7 illustrates the mode of operation of the regenerator of the present invention21- It is something to do.

Procedural amendment (voluntary) Showa s7 year month/3rd Commissioner of the Patent Office Haruki Shimada r.

＼ 1 Display of the case 1982 Patent Application No. 149031 2
Title of the invention Stirling cycle engine 3 Relationship with the case of the person making the amendment Patent applicant 5 Subject of the amendment (3) Drawing (addition) 6 Contents of the amendment As shown in the attached sheet 1- Contents of the amendment 1 Detailed explanation of the invention in the specification Correct the column as follows.

(1) Page 19, line 19, ``Therefore, miniaturization is possible.'' -129119). FIG. 8 shows an embodiment thereof.

In FIG. 8, 71 is a large and low operating engine, 72 is a small low temperature operating engine, 73 is a small high temperature operating engine, 74 is a large high temperature operating engine, 75 is a constant volume operating engine, 82 is a cooler, 83 84 is a combustor, 84 is a regenerator, 87 is an intake section for air or combustion-supporting gas, 89 is a gas discharge section, and there is a fluid passage 7 between them.
Connect with 6.78.79.80.81.77. On this flow path, a check valve 90 is provided downstream of the engine 71, and a flow rate restriction valve 91 is provided downstream of the engine 73. As mentioned above, the cooler and regenerator use a 2-regenerative heat exchanger. To outline the mode of operation of this engine, first, as the engine rotates, air and fuel gas are sucked in from 88 in the figure and mixed at 87.
1, passes through the cooler 82, enters the engine 72, isothermally compressed,
Next, it passes through the regenerator 84, enters the engine 73, is heated isovolumically, and is sent to the combustor 83 as the engine 73 rotates. Here, the air or combustible mixed gas is ignited and combusted upon receiving fuel from 86 and flows into the engine 74 . Next, it passes through the regenerator 84 from the engine 74 and enters the engine 75 where it is cooled equal volumes and then discharged. ” to join.

2. The column of the brief description of the drawings in the specification shall be amended as follows.

(1) From the second line on page 21, add the following text: ``Figure 8 is an explanatory diagram of an example in which the present invention is applied to an internal combustion Stirling cycle engine.''

3. Addition of drawings: Add Figure 8.

that's all

Claims (1)

[Claims] In the rotor housing, the inner peripheral contour is formed by a single-section lochoid curve or a curve that can expand the same dimension in the normal direction, and the outer peripheral shape is
A rotor with a cross section or a lens shape formed by the internal envelope of the locoid or an arc approximating the internal envelope is housed,
The working chamber has a structure in which an internal gear wheel provided on the side surface of the rotor and a fixed external gear wheel provided on the side surface of the rotor housing are combined to form a phase wheel with a tooth ratio of 2:1. A two-chamber rotary piston engine is used, and a pair of large and small rotary seven-piston engines with different working chamber internal volumes are combined to form a pair, and the pair or two pairs are combined and rotated synchronously. Each working chamber is divided into a large low-temperature working chamber, a small low-temperature working chamber, a small high-temperature working chamber, and a large high-temperature working chamber, and the working chambers are connected in the above order by fluid passages to form a circulation path, and the working chamber and The circulation path is filled with working fluid, and a cooler is installed between the large low-temperature working chamber and the small high-temperature working chamber of the circulation path F, and a heater is installed between the small high-temperature working chamber and the large high-temperature working chamber. A regenerator is provided between the working chamber and the small high-temperature working chamber, and the circulation path from the large high-temperature working chamber to the large low-temperature working chamber is routed through the regenerator, and each circulation path is provided with a switching valve as necessary. Alternatively, a check valve or a throttle is provided, and the working fluid is sequentially supplied to each of the working chambers by synchronized rotation of the rotors of each of the rotary piston engines, and the volume difference between the working chambers of each of the engines is reduced. In an engine that performs the Stirling cycle consisting of isostatic compression, isovolume heating, isothermal expansion, and isovolume cooling by giving and receiving heat in the heater or regenerator, one or all of the cooler, heater, and regenerator are used. is a regenerative heat exchanger, and the phase of the synchronous rotation of the rotor of the large high temperature operating engine and the large high temperature operating engine is delayed by 90 degrees from θ° with respect to the rotor of the small low temperature operating engine and the small high temperature operating engine. Stirling cycle featuring! .