JPH0454265A - Heat engine - Google Patents

Abstract

PURPOSE:To acquire a small size and simply structured heat engine by storing a piston made of a material of large coefficient of linear expansion or of a shape memorizing alloy in a cylinder heated or cooled on both sides, simultaneously arranging a permanent magnet or an electromagnet on their opposite surface and using one cylinder. CONSTITUTION:When cycling starts, a piston 4 is drawn to a low temperature side space in a cylinder l as a drive magnet 5 attached on the side surface of the piston 4 is attracted by an electromagnet 3 installed on a low temperature part of the cylinder l. Consequently, working fluid in the cylinder l contains a large amount of high temperature gas and gas pressure in the system is high. Subsequently, when polarity of the electromagnet 3 is changed over, the piston 4 is moved to a high temperature side by a magnetic reaction force, and the working fluid in the system is annealed while passing through a regenerator 2 and gathered in the low temperature side space. Consequently, low temperature gas increases in the working fluid in the cylinder l and the gas pressure in the system becomes low. And, as the piston 4 which makes contact with the cylinder l on its high temperature side has high coefficient of linear expansion, the piston 4 expands and compresses the working fluid in the system.

Description

[Detailed description of the invention] [Industrial usage meter] This invention has no valve mechanism and contains high pressure gas inside.
It concerns a heat engine driven by a heat source and a magnet.

[Conventional technology]

Here, we will focus on the Stirling engine, which is a conventional heat engine that does not have valves and has a closed cycle sealed with high-pressure working gas. Figure 8 shows the configuration of the Stirling engine.

In the figure, 4 is a combustor that is a heat source, and a heater pipe 5
add heat to. 7 is a regenerator that is a heat storage material made of a material such as a wire mesh, 6 is a cooler that removes heat by flowing cooling water, 8 is an expansion piston, and 9 is a power piston, each of which maintains an appropriate phase angle and operates a crank mechanism. It is connected to the crankshaft 10 by.

Next, its operation will be explained. In FIG. 9, if the power piston 9 moves with a phase difference with respect to the expansion piston 8, as the crankshaft 10 rotates, the expansion cylinder volume We and the power cylinder volume To will become a in FIG. and b. A partially excited working gas is sealed inside the engine, and the gases in the high-temperature and low-temperature regions are heated isothermally from the outside (humidity Th
) and cooling <S degrees TO). Now, the gas constant is 8. The volumes of the heater tube 5, regenerator 7, and cooler 6 are respectively Th and Vrlvl, and the average humidity of the regenerator 7 is <
If represented by
r)+C%'c+v1)/TO), and changes as shown in 0 in FIG. Then, if we draw the WIs diagrams of the expansion cylinder and the compression cylinder, a in Figure 1θ, respectively.
, b, and the area enclosed by the diagram is the expansion work wheel and compression work wheel, respectively, and the difference between these Wr = We
-We can be extracted to the outside as work per cycle 0 Then, during one cycle, the high temperature gas moves to the low temperature side and returns again. The regenerator 7 attempts to eliminate heat loss due to the reciprocation of this gas.0 (Problem II! that the invention aims to solve) The conventional Stirling engine is equipped with two independent cylinders as described above. This made the structure complicated and required a large installation space.

The present invention was made to solve these problems, and aims to provide a heat engine that is small and has a simple structure.

[Means to solve the problem]

The heat engine according to this invention fully heats one side of the cylinder,
The other is cooled, high-pressure gas is sealed in the cylinder, the piston is made of a material with a significantly large coefficient of linear expansion or a shape memory alloy, and one end of the cylinder is equipped with an electromagnet for driving the piston, and one end of the histone is also equipped with a permanent magnet. Alternatively, it is equipped with an electromagnet, and the piston is driven by the change in pressure of the working fluid sealed inside the cylinder, which is created by the expansion and contraction of the piston due to the difference in humidity at both ends of the cylinder, as well as magnetic attraction and repulsion, thereby producing work.

[Effect]

When the piston of the heat engine in this invention touches the high-temperature side of the cylinder, it expands due to the heat (returns to its memorized shape), and when it moves to the low-temperature side of the cylinder, it loses heat and contracts, causing a change in volume within the cylinder. When the piston moves, work is generated in combination with a pressure change due to a change in the ratio of high temperature and low temperature parts of the working fluid in the cylinder. explain. 1st
In the figure, 1 is a cylinder heated to a high temperature on one side and cooled on the other. 2 is a heat storage material made of a material such as a wire mesh that has heat distribution from high to low temperatures and is installed inside cylinder 1. 3 is an electromagnet attached to the wall of the cylinder 1 on the low temperature side; 4 is a piston made of a material with a significantly large coefficient of linear expansion; and 5 is a driving magnet, which is a permanent magnet or an electromagnet, and is provided on the end surface of the piston. In this figure, the cylinder l is heated! A heat source for cooling and a cold source for cooling are not shown.

An example of a method for extracting work from this heat engine is shown in FIG. In the figure, 14 is a cylinder for output output;
6 is an output piston for taking out the output; 7 is a piston pin connected to the output piston 6 and sealed by a shaft seal 8 provided in the cylinder 1; 9 is a piston pin that connects the piston lid 7 to the connecting rod IO; Reference numeral 11 denotes a crankshaft which rotates due to the reciprocation of the output piston 6, bearings which rotatably support the crankshaft U at both ends, and a flywheel which stores rotational motion as inertial force.

Next, this cycle will be explained using FIGS. 1 and 2. Assuming that the cycle starts from the state (■) in the PVii diagram of Figure 2, the piston 4 is moved by the driving magnet 5 attached to the end face of the piston being pulled by the electromagnet 3 attached to the low temperature part of the cylinder 1, It depends on the side space. As a result, the working fluid inside the cylinder contains a large amount of high-temperature gas, and the gas pressure within the prefecture is high.

Next, the process of moving to state (2) will be explained. When the polarity of the electromagnet 3 is switched, the piston 4 is moved to the high temperature side by the reaction force of the magnetic force, and the working fluid in the prefecture is slowly cooled while passing through the regenerator 2 and collects in the low temperature side space. At this time, although not shown in this figure, the space between the circumferential direction of the piston 4 and the cylinder 1 is sealed by a piston ring or a seal, and there is no leakage from the circumferential direction of the piston 4.

As a result, the working fluid in the cylinder 1 is made up of low-temperature gas, and the gas pressure in the system becomes low.

(The state of ■ in the PVii diagram in Figure 2, that is, the pressure decreases while the volume inside the system remains constant.) To explain the state of ■ after drying, the piston 4 in contact with the high-temperature side cylinder 1 has a high linear expansion. Because it has a coefficient, it expands and compresses the working fluid in the system, increasing the pressure in the system. In other words, the volume of the working fluid in the system decreases while remaining at an isothermal temperature, and the pressure increases.

(Status ■ in the PV+W diagram of FIG. 2) Next, the condition ■ will be explained. When the magnetism of the electromagnet 3 is switched again, the piston 4 quickly moves to the cold side of the cylinder 1 due to the attraction force of the magnetic force and the fact that the working gas is compressed.The working fluid passes through the regenerator 2 again. The working fluid inside the cylinder is heated, and the amount of high-temperature gas increases, which further increases the pressure within the system. That is, the pressure of the working fluid in the system increases while the volume remains the same as in (2). (PvIIIrgJ in Fig. 2)) Then, the piston 4 in contact with the low-temperature side cylinder 1...
The system contracts and the working fluid in the system expands, reducing the pressure in the system and returning to state (■).

By repeating this, a cycle is constructed, and the pv
It generates work equivalent to the area surrounded by the m diagram.

Now calculate how much work this heat engine can generate under ideal conditions.

However, this calculation is not optimized because the shape of each part was determined appropriately, and it is calculated in a highly idealized state, so it is only an approximation. +graphite, and the diameter of the piston 4 is 1L, and the length is 200mm. Humidity on the high temperature side'l1ll 100 C1 Humidity on the low temperature side! ro
L80D, filling pressure inside cylinder 1 is lQMp
a, the regenerator 2 is cylindrical, and its bore diameter is 2 (II
shall be. The working fluid is water.

Since the displacement of the piston 4 due to thermal expansion is 1.76111, the stroke is set to 1.8fi. Assuming that the cycle of this engine changes from isovolume compression, isothermal compression, isovolume expansion, and isothermal expansion, assuming that the efficiency of the regenerator 2 is 100%, and assuming that there is no friction loss due to the reciprocation of the piston 4, This engine produces 0.09 J of work per stroke, and if four strokes per second can be achieved, 1.8 W of power can be obtained. Therefore, if you use a heat source such as exhaust heat of about 100C and apply it to the high temperature side of this engine, the energy input to the magnet (determined by the frictional work of the piston 4) is smaller than the power obtained from the engine. do the work of If the engine is designed optimally, an engine that uses a low-quality heat source can be realized.

Next, an example of a method for extracting work from this heat engine will be explained with reference to FIG. The low-temperature side space of the cylinder 1 is connected to a room in which the output piston 6 of the output extraction cylinder 14 is driven, and the output piston 6 is connected to a crank mechanism (7 to U).
Since the pressure change occurring in the low temperature side space is transmitted to the output piston 6, the output piston 6 is pushed up, and the output piston 6 returns to its original position due to the rotational energy of the flywheel. In this way, the work generated by the heat engine is converted into rotational force.

In the above embodiment, the material of the piston 4 is Teflon + graphite, and by making the piston 4 elongated, the amount of deformation stroke due to thermal expansion is increased, and the incompleteness of the seal due to expansion in the radial direction is suppressed. As shown in Figure 7, a material with a high coefficient of linear expansion is used for the core material n, a material with a low coefficient of linear expansion is used for the piston member field, and the cylinder 1
For example, by providing a piston ring U on the outer shoe of the piston member, a higher-performance engine can be realized by increasing the stroke of the piston due to thermal expansion. At this time, in order to improve heat conduction, the core material 4 is configured to penetrate to the end face of the piston member field and directly contact the cylinder 1 on the high temperature side and the low temperature side. This is necessary to improve the expansion reaction time of the piston. In the above example, a crank mechanism was used as a method for extracting work, but as shown in Fig. 4, a magnet is attached to the shaft end of the piston rod 7. If a coil 16'F is installed on the magnet's 7N'), the pressure change generated in the low temperature side space of the cylinder 1 will be transmitted to the output piston 6, pushing up the output piston 6, and the piston loft 7 will also move accordingly. As a result, the coil is pushed up and the magnet moves back and forth in the middle of the coil, causing current to flow through the coil, which operates as a linear generator, allowing work to be extracted as electrical work. Furthermore, although a magnet is attached to the shaft end of the piston rod 7 in FIG. 4, a coil may be attached to the piston rod and surrounded by a magnet. Furthermore, as shown in Fig. 6, the sea urchin cylinder 1
By attaching a pressure element to a part of the heat engine and rectifying the current generated from the pressure element r due to pressure fluctuations in the heat engine
The rectifier circuit is not shown), which can be taken out as electrical work.In addition, the piston 4 in FIG. 1 was made of a material with a significantly high coefficient of linear expansion in the above embodiment, but as shown in FIG. The piston m is made of shape memory alloy,
This shape is memorized so that it will return to its original shape at high temperatures, and then compressed using a press to form the piston shape at low temperatures.When the piston contacts the high temperature part of cylinder 1, it returns to its original shape and compresses the working fluid. If you do this, you can get the same effect.

〔Effect of the invention〕

As described above, according to the present invention, a cycle in which work is generated by one piston can be configured, and a heat engine with a simple mechanism can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a line cross-sectional view showing an embodiment of the present invention and its operating mode, Fig. 2 is a PV diagram showing the relationship between pressure and volume of Fig. 1, Fig. 8, Fig. 4, Fig. Figure 6 is the first
Figure 6: Route cross-sectional diagram showing the method for extracting work.
The figure is an external view showing method 1 of manufacturing a piston with shape memory alloy, Figure 7 is another example of the piston used for the one in Figure 1, A is a cross-sectional view, the opening is, and 8 is a cylinder. Figure 8 is a cross-sectional view of a Stirling engine, which is a conventional heat engine, and Figure 9 is a diagram plotting the volume change and pressure change of this conventional device for each crank angle. FIG. 10 is a PV diagram of each cylinder. In the figure, 1 is a cylinder, 2 is a regenerator, 3 is an electromagnet, 4 is a piston, 5 is a driving electromagnet, 2D is a shape memory alloy piston, 22 is a core material, the container is a piston member, and the piston ring is required. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] It has a cylinder whose one end is heated to a high temperature, the other end is cooled to room temperature or a low temperature, and whose interior is pressurized to a high pressure by a gas with a small molecular weight (internal working fluid).The cylinder has a built-in piston, and this piston is A round-trip room and
The reciprocation of the piston causes the internal working fluid to flow, creating a chamber containing a regenerator that has a humidity gradient from high temperature to low temperature. Alternatively, a heat engine characterized in that it has a driving magnet made of an electromagnet, and an electromagnet that determines the direction of movement is provided at one end of the cylinder opposite to the driving magnet of the piston.