JPS6044573B2 - Cold expansion engine starting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting device for a low temperature expansion engine used in a liquefaction and refrigeration system.

Liquefaction and refrigeration equipment such as helium liquefaction equipment has an expansion engine that adiabatically expands working gas such as helium, and a power absorption device such as a flywheel is used to recover the expansion work generated by this expansion engine. using a mechanism.

In this low-temperature expansion engine, high-pressure gas cannot be introduced unless the valve timing is set to the absorption stage, so it cannot be started. For this reason, conventional low-temperature expansion engines rely on human power or an external power source to start, either by manually rotating a flywheel installed on the power absorption shaft, or by applying rotation with a starter device such as a motor. Ta.

However, starting using manual power or an external power source not only makes it difficult to simplify and save labor for the entire device, but also has the drawback of complicating maintenance. SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-mentioned drawbacks and to provide an apparatus for starting a cold expansion engine using high pressure gas used in a liquefaction and refrigeration system.

This will be explained in detail below using figures.

FIG. 1 is a system diagram showing one embodiment of the present invention, and FIG. 2 is a system diagram showing another embodiment of the invention.

First, an embodiment of the present invention will be described with reference to FIG.

The liquefaction device according to the present invention consists of a compressor 1 for a working gas such as helium and a cold box 2, in which a heat exchanger 3 for compressed working gas and a cold expansion engine 4 are installed. .

The high pressure gas leaving the compressor 1 passes through a conduit 5, a heat exchanger 3, and a cold expansion engine 4. The expanded working gas leaving the cold expansion engine 4 passes through the heat exchanger 3 via conduit 6 and is returned to the compressor 1. The heat exchanger 3 exchanges heat with the working gas that has come out of the compressor 1 and is now at room temperature and high pressure, and the working gas that has expanded and returned to the compressor 1 at a low temperature, thereby cooling the working gas. The low-temperature expansion engine 4 is usually a reciprocating piston type engine, and rotates a power absorption shaft 8 via a crank 7 . This low-temperature expansion engine 4 may not be able to start depending on the valve timing of the intake valve 9 and exhaust valve 10. Therefore, it is necessary to rotate the power absorption shaft 8 to a valve timing that allows starting. Conventionally, a starting electric motor was provided to rotate the flywheel, or a flywheel 11 provided on the power absorption shaft 8 was manually rotated, but in the present invention, the flywheel 11 is coaxially or interlocked with the power absorption shaft 8 to rotate the flywheel. A pressure drive motor, in this embodiment a pneumatic pen motor 12, is provided, and the pneumatic pen motor 12 is driven to rotate by using the working gas which has come out of the compressor 1 and has become under high pressure. The rotational drive mechanism of the pneumatic pen motor 12 is provided with a one-way clutch that transmits only the drive output, bypassing the high-pressure working gas from the high-pressure working gas conduit 5 and passing it through the orifice 13 and the control valve 14. The liquid is introduced into the surge tank 15, and then passes through the on-off valve 16 to reach the pneumatic pen motor 12, where it is rotated.
The working gas which has been expanded by the pneumatic pen motor 12 is discharged into a conduit 6 which returns to the compressor 1. The control valve 14 is controlled by a speed regulating mechanism 17 so as to be closed when the power absorption shaft 8 exceeds a predetermined rotation speed. The operation of the starting device for a low-temperature expansion engine of the present invention constructed as described above will be explained.

The high-pressure working gas discharged from the compressor 1 passes through a conduit 5 and on the other hand passes through a heat exchanger 3 to reach a low-temperature expansion engine 4, but the engine cannot be started because the valve timing does not match. The working gas in conduit 5 passes on the other hand via orifice 13 and control valve 14 to surge tank 15 . In this case, the control valve 14 is in an open state because the power absorption shaft 8 has not yet rotated. The high-pressure working gas in the surge tank 15 is introduced into the pneumatic pen motor 12 through an on-off valve 16 that is opened and closed manually or by a self-acting blowout mechanism, and rotates the power absorption shaft 8. Therefore, the crank 7 of the low-temperature expansion engine 4 is rotated, and the valve timing becomes ready for starting.
The low-temperature expansion engine starts and rotates automatically. When the low-temperature expansion engine 4 starts rotating, the control valve 14 linked to the speed regulating mechanism 17 is closed, gas supply to the surge tank 15 is stopped, and the rotation of the pneumatic pen motor 12 is stopped. The working gas that has undergone expansion work in the pneumatic pen motor 12 is returned to the conduit 6, compressed again by the compressor 1, and used. As shown in FIG. 2, a reciprocating pneumatic engine 18 may be used instead of the pneumatic pen motor.Furthermore, as shown in FIG.
For example, a method may be adopted in which the rotation of the bellows device 21 is transmitted to the hydraulic pump 20 by the belt 19, and the bellows device 21 is expanded and contracted by the hydraulic pressure generated by the hydraulic pump to control opening and closing.

As explained above, according to the present invention, since the working gas used in the liquefaction and refrigeration system is used to start the low-temperature expansion engine, no human power or external power is required. This makes it possible to simplify the device and save labor.

Further, by using the starting fluid pressure drive motor of the present invention, that is, the pneumatic pen motor in this embodiment, as a brake, it is also possible to control the rotation of the cold expansion engine.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing one embodiment of the present invention, and FIG. 2 is a system diagram showing another embodiment of the invention. DESCRIPTION OF SYMBOLS 1...Compressor, 3...Heat exchanger, 4...Low temperature expansion engine, 12...Pneumatic vane motor, 18...Reciprocating type pneumatic engine.

Claims (1)

[Claims] 1. Room-temperature, high-pressure gas sent out from the compressor is introduced into a reciprocating piston-type low-temperature expansion engine via an intake valve, and after operating the engine and driving a power absorption shaft, it becomes low-temperature expansion gas and passes through an exhaust valve. In the liquefaction refrigeration system, a bypass flow path is provided between the introduction flow path for the room temperature high pressure gas and the return flow path for the low temperature expanded gas, and the power absorption shaft is connected to the power absorption shaft in the bypass flow path. A fluid pressure drive motor operated by room temperature, high pressure gas that starts the motor, a speed adjustment mechanism that is activated by the rotation of the power absorption shaft, and a speed adjustment mechanism that works in conjunction with this speed adjustment mechanism to control the power absorption shaft to close when it exceeds a predetermined rotation speed. A starting device for a cold expansion engine equipped with a control valve.