JPS6221976B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure control device for a Stirling engine, and more particularly to a pressure control device for a Stirling engine equipped with a pressure regulating valve.

A Stirling engine expands working gas isothermally between an expansion chamber, which is a high-temperature part, and a compression chamber, which is a low-temperature part, in a cylinder chamber that is divided by a working piston.
The output is taken out to the outside by reciprocating while undergoing isovolume change, isothermal compression, and isovolume change, and the output is approximately proportional to the average pressure of the working gas in the closed circuit. On the other hand, it is not possible to completely prevent the working gas in a closed circuit from leaking from the rod part and other parts that take out the output to the outside, and as a result, the average working gas pressure decreases due to gas leakage in the closed circuit. is unavoidable. For this reason, the compressor is operated in response to the pressure drop of the working gas in the closed circuit to supply the working gas and prevent a drop in output.
Also, when the output of the Stirling engine increases or decreases, the compressor combined with the check valve and pressure increase/decrease valve is operated to adjust the output, but external energy is required to operate this compressor, making it difficult to use energy effectively. This is not a good idea from the viewpoint of this, and furthermore, the responsiveness of the pressure adjustment of the working gas is not sufficient.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a pressure control device for a Stirling engine that uses a cylinder equipped with a pressure regulating valve to compensate for working gas leaking to the outside.

That is, according to the present invention, in order to achieve the above-mentioned object, a cylinder equipped with a pressure regulating valve is connected to the working space of a Stirling engine through a tank, a supply valve, and a check valve, and the working gas at maximum output is Provided is a Stirling engine characterized in that a pressure regulating valve is opened when the lowest pressure of the cylinder becomes less than a predetermined level, so that working gas from a cylinder can be supplied to a working space.

Embodiments of the invention will be described with reference to the accompanying drawings.

The working piston 3 in the cylinder 2 of the Stirling engine 1 partitions the cylinder 2 into an expansion chamber 4 serving as a high temperature section and a compression chamber 5 serving as a low temperature section. The compression chamber 5 communicates with the expansion chamber of an adjacent cylinder (not shown) via a cooler, a heat storage device, and a heater to form a closed circuit. The compression chamber 5 is connected to a circuit 13 with a check valve 6 and a supply valve 7 allowing the flow of working gas into the compression chamber, which circuit 13 communicates with a tank 8 and a cylinder 10 with a pressure regulating valve 9. do.
A second circuit 14 having a check valve 11 and a pressure reducing valve 12 is connected to the first circuit 1 in parallel with the circuit 13.
Connect to 3. Thus, the tank 8 connected to the cylinder 10 makes it possible to supply working gas to the compression chamber 5 via the supply valve 7 and the check valve 6, and from the compression chamber 5 to the check valve 11 and the pressure reducing valve 12. allows backflow of working gas into tank 8 via.

Next, the operation of the pressure control device shown in FIG. 1 will be described.

Open the supply valve 7, and open the cylinder 10 and tank 8.
The working gas is supplied to the compression chamber 5 which becomes the working space, and the working gas is sealed in the closed circuit between the compression chamber 5 and the expansion chamber to a predetermined pressure level A (see Fig. 2). 8. Set the internal pressure to this level A. On the other hand, the pressure regulating valve 9 provided in the cylinder 10
The set pressure is the lowest pressure level B (third
(see dotted line in the figure). In other words, the pressure when the supply valve 7 is fully open (maximum output) is the lowest pressure level B, and the pressure when the pressure reducing valve 12 is fully open (minimum output) is the highest level C of the pressure fluctuation waveform shown by the working gas. (See the two-dot chain line in Figure 3). the result,
It becomes possible to control the pressures in the compression chamber 5 and the expansion chamber 4 between pressure levels B and C, thereby achieving engine output control.

By the way, leakage of the working gas occurs around the rod 15 and other parts, and the minimum pressure of the working gas at maximum output becomes below level B, and the supply valve 7
When is open, a pressure below the level B is introduced into the tank 8, and the pressure regulating valve 9 is opened by the low pressure gas introduction signal, and working gas is supplied from the cylinder 10 to bring the pressure in the tank 8 to a predetermined pressure level. B or more, supply valve 7
The working gas in the tank 8 is supplied to the compression chamber 5 via the check valve 6 to compensate for gas leakage.

As is clear from the above, in this invention, a cylinder equipped with a pressure regulating valve is connected to the working space of a Stirling engine via a tank, a supply valve, and a check valve, so that the minimum pressure of working gas at maximum output is maintained at a predetermined level. When the pressure drops below the level, the pressure regulating valve is opened and working gas from the cylinder is supplied to the working space, so it is possible to compensate for the working gas without the need for a compressor like in the past, resulting in stable operation. You can get the output. Further, since the working gas can be supplied by simply opening the pressure regulating valve, responsiveness is also good.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a pressure regulating device for a Stirling engine as an example of the present invention, FIG. 2 is a diagram showing pressure levels, and FIG. 3 is a diagram showing the relationship between pressure changes of working gas and valve openings. In the diagram: 1... Stirling engine, 2... cylinder,
3... Working piston, 5... Compression chamber, 6, 11... Check valve, 7... Supply valve, 8... Tank, 9... Pressure adjustment valve,
10...Cylinder.

Claims (1)

[Claims] 1. A cylinder equipped with a pressure regulating valve is connected to the working space of the Stirling engine via a tank, a supply valve, and a check valve, and when the minimum pressure of the working gas at maximum output falls below a predetermined level, the pressure regulating valve is closed. A pressure control device for a Stirling engine, characterized in that the cylinder is opened so that working gas from the cylinder can be supplied to the working space.