JPS59117457A - Superconductive rotary electric machine - Google Patents

Abstract

PURPOSE:To accurately detect the liquid surface in an inner cylinder by forming an auxiliary hole in a bore side of an L-shaped pipe which is opened at one end at the inner periphery of the inner cylinder of a rotor and opening the other end with a constant-pressure chamber which has lower pressure than the static pressure in the inner cylinder. CONSTITUTION:One end of an L-shaped pipe is opened at 11a in the vicinity of the inner peripheral surface of the interior 10 of a rotor inner cylinder 2, on which a field winding 1 is wound for a superconductive rotary electric machine, and an auxiliary hole 11b is formed in the bore side. The other end is connected to an exhaust hole 13 formed at the outer periphery of a rotational shaft 4a. The hole 13 communicates with a constant-pressure chamber 16 which has lower pressure than the interior 10 of the inner cylinder. When liquid helium is fed under pressure to the interior 10 of the inner cylinder as designated by an arrow 19, the helium is urged by the centrifugal force to the inner periphery to cool the coil 1, and the evaporated helium is flowed to the directions of arrows 20, 21, but cooling is proceeded, and when the liquid helium reaches the hole 11a, the gaseous helium is flowed from the auxiliary hole 11b, and when the helium reaches R4 at the liquid surface, the gaseous helium does not flow. The liquid surface in the inner cylinder 10 can be detected accurately by detecting the variation in the dynamic pressure in this case.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a superconducting rotating electrical machine with an improved structure of a liquid level detection device.

[Technical background of the invention and its problems]

Large-capacity superconducting rotating electric machines such as superconducting generators have high operating efficiency, and early commercialization is desired. Liquid helium is used as a coolant to cool the rotor's superconducting field windings. During operation, a predetermined amount of liquid helium must be stored in an inner cylinder equipped with superconducting field windings.
For this reason, a highly reliable liquid level detecting device is desired.

Conventionally, there has been a detection device as shown in FIG. 1 or 2. In the device shown in Fig. 1, in order to detect the amount of liquid helium (221) stored in the inner circumference (2), a carbon resistor (c) was used as a liquid level gauge to detect the position of the liquid level. In the device shown in Figure 2, the temperature distribution in the radial direction, that is, the position of the liquid level, can be detected by installing multiple elements (properties) with good temperature resolution, such as germanium resistance thermometers, inward (2). was.

These measurement methods all apply the principle that the resistance of the carbon resistor (231) and the element (24) change depending on the temperature. Generally, a slip ring (not shown) is required to measure the combined resistance with rg or to supply a constant current to the element Q.Also, if a slip ring is not used, According to these electrical liquid level detection methods,
Due to aging of the resistor (23) and element Q41, and the high-speed rotation of the device when using a slip ring, the brush is often worn, and maintenance of the liquid level detection device requires considerable effort. Furthermore, when an FM transmitter is used, the device becomes complicated and expensive.

However, to date, no mechanical liquid level detection device that is highly reliable and easy to maintain has been announced as a replacement for the above-mentioned liquid level device.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a superconducting rotating electric machine that has a simple structure, is inexpensive, and has a highly reliable liquid level detection device.

[Summary of the invention]

In the present invention, one end is opened as a main opening inside the inner cylinder storing cryogenic refrigerant for cooling the superconducting field winding of the rotor, and an auxiliary opening is located on the inner diameter side of the main opening. An L-shaped ventilation pipe with an open end is provided, and the ventilation pipe is guided in the axial direction of the rotor, so that the ventilation pipe is shielded from the outside air on a part of the outer peripheral surface of the rotating shaft, and is further removed from the internal static pressure of the inner cylinder. The cryogenic refrigerant in the inner cylinder is discharged through a constant pressure chamber with low pressure, and the liquid level of the refrigerant is detected based on the change in the discharge amount. Gas is guided from the outer circumferential hole of the rotating shaft of the superconducting rotating electric machine to the inner cylinder through the rotating kite tube, and the positional relationship between the liquid refrigerant level stored in the inner circumference and the opening at the end of the ventilation pipe is determined. ζThus, by utilizing the change in the amount of evaporated gas passing through the ventilation pipe, liquid level detection can be performed with a simple structure, at low cost, and with high reliability.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. Note that the corresponding symbols are also given to Figures 1 and 2, so please use them as a reference for understanding the conventional example. Figure 3 is a vertical cross-sectional view of a rotor according to an embodiment of the present invention. The stator is not shown. An inner cylinder (2) equipped with a superconducting field winding (1) and a torque tube (3) have one end directly connected to the rotating shaft (4a) on the non-casing side. , the other end is connected to the direct rotation shaft (4b) through a support (5) that has a degree of freedom in the axial direction.The inward direction (2) is covered with a damper (6), and the A radiation shield plate (7) is provided to prevent radiant heat, and the space (9) closed by the outer periphery (8) is kept in a vacuum state.Liquid helium is contained inside the inner cylinder (2). (24 is supplied/
The L-shaped ventilation pipe (IJ) is provided with its main opening (1, i a ) facing in the radial direction.The ventilation pipe (11) is installed in the center hole ( L2), and is connected to an exhaust hole 03) provided on the outer periphery of its rotating shaft (4a). Is the exhaust hole α3) sealed (15)? A low pressure chamber (L6) ζ is thus isolated from the outside air and kept at a constant pressure lower than the static pressure inside the inner cylinder α0). Low pressure chamber (6)
A pressure regulating valve (16a) and an IJ-F valve (16b) are installed in the pump, and a valve is placed between the pump (L7) and the low pressure chamber (L6).

FIG. 2 is an enlarged view of a portion of the ventilation pipe I that protrudes into the inner pipe interior θ0). The main opening (lla) is the L-shaped tip, and the auxiliary opening (1lb) is located on the inner diameter side, that is, on the side closer to the central axis of the rotor. In addition, when the liquid level closes the auxiliary opening (llb), the valve is immediately closed and the supply of liquid helium is stopped at the same time.

Next, the operation in such a configuration will be described.

When the rotor is rotated and liquid helium (22) is pumped as shown by the arrow from the opposite end of the rotating shaft in Fig. 1 and stored in the inner cylinder (L(1)), liquid helium (22) is It is pressed against the inner periphery of the inner cylinder (2) by centrifugal force and circulates around the superconducting field winding (1) to cool the superconducting field winding (1). (not shown) passes through the path (20) while being cooled and is collected from a part of the rotating shaft (4a) on the non-direct coupling side.A part of the torque tube (3) is also cooled and collected from the non-direct coupling side in the pass (21). It is recovered from a part of the rotating shaft (4a).Here, the details of the paths (20) and (29) and the recovery device will not be explained because conventionally known ones are used.By the way, liquid helium (inside the inner periphery of the
10), since most of the members constituting the rotating electric machine are close to room temperature, the liquid helium (22), which has a small latent heat of vaporization, immediately vaporizes. Therefore, the inner periphery θ0) is assumed to be helium gas. On the other hand, bus (20), (2
)) and the temperature difference (density difference) of the helium gas, the internal static pressure of the rotating inner cylinder (2) is Q, 5b.
It drops to about ar. The exhaust hole (13), which is the outlet of the ventilation pipe (11), is provided with a low pressure chamber α6) that maintains a constant pressure lower than that, so the opening on the ventilation pipe side (ha
) and (11b), helium gas is guided in the direction of pump α7). The exhaust flow velocity can be detected as a dynamic pressure by a pitot tube (not shown) installed on the exhaust side of the exhaust hole 03). When the inner tube (2) and others are cooled, liquid helium (2
2) is gradually stockpiled, and the liquid level reaches the radius R8 in Fig. 4.
Even if the dynamic pressure changes from to the position of radius R0, the above-mentioned dynamic pressure does not change. However, when more liquid helium is supplied, the liquid level reaches the position of radius R2, that is, the main opening (l
When the helium gas comes into contact with the inner cylinder (10), the helium gas that fills the inner cylinder (10) is discharged using the auxiliary opening (llb) as an inlet.

At this time, the ventilation resistance on the ventilation pipe side increases, so the discharge amount decreases and the detected dynamic pressure also decreases. When the liquid level further changes to the position of radius R3, the auxiliary opening (1lb)
begins to be blocked by liquid helium (2 odors), and a sudden decrease in the discharge amount is detected until the liquid level reaches the radius (change in liquid level corresponding to the diameter of the auxiliary opening (llb)), and the liquid level reaches the radius. At position R4, there is almost no discharge amount.When the liquid level becomes smaller than the radius, the inside of the ventilation pipe (11) is inside the inner cylinder ([
In order to prevent the liquid helium (22) from being pumped out because the pressure is more negative than 0), the valve α8) is moved from the liquid level radius R2 to the radius R4, as described in the explanation of the device configuration.
Operate at an intermediate position.

FIG. 5 shows the above-mentioned state with time on the horizontal axis and dynamic pressure on the vertical axis. Of course, this is liquid helium (2
21 indicates when the number increases, and the same applies when the liquid decreases. The arrows pointing from R8 to R4 in FIG. 5 roughly correspond to the positions of each radius R8 to R4 of liquid helium. By detecting the amount of helium gas discharged in this manner, changes in dynamic pressure can be clearly recognized, so that a superconducting rotating electric machine capable of highly reliable liquid level detection can be provided.

Furthermore, according to this example, ventilation pipes (0]), low pressure chambers (1)
6) The liquid level detection device, which consists of a pressure regulating valve (16a), a relief valve (16b), a pump σ7) valve (18), etc., can be used as an emergency exhaust system in the event of an accident. This will help you understand the safety of your vehicle. When the superconducting field winding (1) is quenched, the winding ii(]
) The pressure in the inner cylinder gBQo) rises as the temperature rises. At this time, the helium gas passes through the ventilation pipe 01) and flows into the low pressure chamber (16), and the relief valve (16b) opens and is released to the outside air, or the valve (I8) is open at that time. If so, it is evacuated by the pump (17). Therefore, this embodiment is a scale that operates not only as a liquid level detection device, but also as an emergency light in the event of an accident, thereby increasing the reliability of the device.

Next, Fig. 6 is shown as a different embodiment, but in this case, the radial position of the main opening (1la) at the tip of the ventilation pipe 01) shown in Fig. 3 is different from the central axis of the rotor (R2\ R
4) The only difference is that there are two mutually independent ventilation systems and a low-pressure chamber (not shown) is provided as mutually independent rooms, but the rest is the same as the embodiment shown in Figure 3, and is modeled and shown. It is something.

Even in this case, the same operation and effect as the embodiment shown in FIG. 3 can be obtained. In addition, the present invention provides that the ventilation pipe (11) may be used as a substitute for the ventilation pipe by providing a ventilation passage in the end wall of the inner cylinder (2), etc. without changing the gist of the content, including but not limited to:
Of course, it can be implemented with various modifications.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a superconducting rotating electrical machine that can detect the level of liquid helium in an inner cylinder with high reliability and can also be operated as an emergency exhaust system. can.

[Brief explanation of drawings]

Figures 1 and 2 are explanatory diagrams modeling the main parts of liquid level detection devices of different conventional superconducting rotating electric machines, respectively.
The figure shows the superconducting rotating electric machine of the present invention. Figure 5 is a curve diagram showing the detection signal of the liquid level position of the device in Figure 3, and Figure 6 is a modeled explanation of the main parts of the side surface detection device of a different embodiment. It is a diagram. 2...Inner cylinder, 4a, 4b...Rotating shaft, 10...
Inner circumference interior, 11... Ventilation pipe, lla... Main opening,
llb...Auxiliary opening, 13...Exhaust hole, 16...
-Low pressure chamber, 16a...pressure regulating valve, 16b...relief valve, 17...pump, 18. valve, 22...liquid helium which is a cryogenic reagent. Agent Patent Attorney Mr. Inoue Figure 4 Figure 5 Shunma Figure 6

Claims (2)

[Claims] (1) One end is opened as a main opening inside the inner cylinder that stores the cryogenic refrigerant that cools the superconducting field winding of the rotor, and an auxiliary opening is opened at the inner diameter side of the main opening. An L-shaped ventilation pipe is arranged in the axial direction of the rotor, and the ventilation pipe is located in a part of the outer circumferential surface of the rotating shaft, which is shielded from the outside air and whose internal static pressure is lower than the internal static pressure of the inner cylinder. A superconducting rotating electric machine characterized in that a cryogenic refrigerant in an inner cylinder is discharged through a constant pressure chamber, and a liquid level position of the refrigerant is detected based on a change in the discharge amount. (2) The constant pressure chamber is equipped with a pump and a pressure regulating valve, and a valve is installed to prevent the liquid cryogenic refrigerant inside the inner cylinder from being sucked into the constant pressure chamber, which occurs when the superconducting field winding is quenched, etc. 2. A superelectric, constant rotation electrical machine according to claim 1, characterized in that an emergency exhaust system is provided in response to an increase in internal static pressure of the inner cylinder.