JP3799372B2 - Liquid target temperature measurement channel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
Liquid target temperature measurement channel that measures the temperature of the liquid metal flowing in the target container in a liquid target that irradiates the liquid metal flowing in the target container with a charged particle beam and generates neutrons in the liquid metal by nuclear fragmentation. About.
[0002]
[Prior art]
The structure of the liquid target for the nuclear spallation neutron source so far does not cause a partial temperature rise (hot spot) due to the recirculation flow of the fluid or the stagnation region of the flow. The position and shape of the distribution rectifier plate arranged in the box have been studied. However, studies for measuring the temperature of liquid metal flowing in the target container have been delayed.
[0003]
When a charged metal beam is irradiated to a liquid metal flowing in the target vessel of a liquid target for a spallation neutron source and neutrons are generated from the liquid metal by spallation, the liquid metal is Fever fever. In order to measure the temperature of the liquid metal flowing in the target container that generates heat extremely, it is appropriate to use a sheathed thermocouple that has a proven record in a sodium loop or the like. That is, a sheath type thermocouple is used, a temperature measuring point at the tip thereof is placed in the flow of the liquid metal in the target container, and the temperature of the liquid metal flowing in the target container is measured.
[0004]
[Problems to be solved by the invention]
From the viewpoint of the strength of use of the sheathed thermocouple, the sheathed thermocouple is exposed to the liquid metal flowing in the target container, so the sheath must be thick and thick in consideration of strength and erosion. I must. Alternatively, the sheath type thermocouple must be protected by a well (sheath tube) or the like.
[0005]
However, with such a structure, the response speed of the measured value with respect to the temperature of the sheath type thermocouple is slowed, and the flow of the liquid metal is hindered. For this reason, considering the response speed of the measurement value and the flow of the liquid metal, a structure in which the sheath-type thermocouple is made thin along the wall surface in the target container can be considered.
[0006]
However, with such a structure, the temperature of the fluid cannot be accurately measured this time, and as a result, the temperature of the inner wall surface of the target container is measured.
For these reasons, there is a need for a sheathed thermocouple mounting structure in which the sheathed thermocouple can accurately measure the temperature of the liquid metal without hindering the flow of the liquid metal.
[0007]
In view of the problem of measuring the temperature of the liquid metal flowing in the target vessel of the liquid target for the spallation neutron source, the present invention aims at the liquid metal flowing in the target vessel by the sheath type thermocouple. An object of the present invention is to provide a liquid target temperature measurement channel that can accurately measure the temperature of the liquid metal without impeding the flow.
[0008]
[Means for Solving the Problems]
In the present invention, in order to achieve the above-mentioned object, the sheath-type thermocouple 6 is not attached to the wall surface of the target container 1 through which the liquid metal flows, but is disposed in the target container 1 and flows into the target container 1. A sheath type thermocouple 6 is attached to the distribution rectifying plate 5 for adjusting the metal flow, and the temperature measuring contact 7 is projected from the distribution rectifying plate 5 into the liquid metal flow.
[0009]
That is, the liquid target temperature measurement channel according to the present invention irradiates a liquid metal flowing in the target container 1 with a charged particle beam and generates neutrons from the liquid metal by nuclear fragmentation. In order to measure the temperature of the flowing liquid metal, a sheath type thermocouple 6 is attached to a distribution rectifying plate 5 which is arranged in the target container 1 and adjusts the flow of the liquid metal flowing into the target container 1, and this sheath type thermoelectric. The pair of temperature measuring points 7 are arranged so as to protrude from the surface of the distribution rectifying plate 5. For this purpose, the distribution rectifying plate 5 is entirely or partially hollowed, and a hollow weight-like projection 8 is provided on the surface thereof, and the temperature measuring point 7 at the tip of the sheath-type thermocouple 6 is provided from the inside of the distribution rectifying plate 5. Is led to the tip of the protrusion 8, and the temperature measuring point 7 is sealed with the tip of the protrusion 8.
[0010]
The weight-shaped protrusion 8 has a thick base and rises from the distribution rectifying plate 5, and has a small volume at the tip. For this reason, it is possible to ensure the strength of the protrusion 8 that holds the temperature measuring point 7 of the sheathed thermocouple 6 and to reduce the heat capacity in the vicinity of the temperature measuring point 7 and to ensure the responsiveness of temperature measurement. .
[0011]
Further, when the protrusion 8 gives a strong resistance to the flow of the liquid metal, the flow of the liquid metal is disturbed, which causes a Kalman vortex street or the like behind the protrusion 8. Therefore, it is preferable that the protrusion 8 has a flat shape or a streamline shape that is long in the flow direction so that the protrusion 8 does not affect the flow of the liquid metal as much as possible. On the other hand, in order to measure the temperature of the liquid metal with high responsiveness using the sheath type thermocouple 6, it is preferable that the volume of the protrusion 8 is small at the temperature measuring point 7. Therefore, the protrusions 8 a base side of the rising portion and a long flat in the direction of the liquid metal flow to the apex side of the projections 8 which temperature measuring point 7 of the sheath-type thermocouple 6 is sealed with the small diameter of the conical Is good.
[0012]
Furthermore, in order to minimize the influence of the protrusion 8 on the flow of the liquid metal, a plurality of protrusions 8 are provided on the surface of the distribution rectifying plate 5, and the protrusion 8 is adjacent to the liquid metal flow direction. It is preferable to dispose the object in a direction perpendicular to the liquid metal flow so as not to overlap the liquid metal flow direction.
[0013]
In this way, by arranging the liquid target temperature measurement channel inside the target container 1 for generating spallation neutrons, without greatly affecting the flow of the liquid metal flowing in the target container 1, Variations in the temperature of the liquid metal that occur when the charged particle beam is irradiated onto the liquid metal can be measured with good responsiveness.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described specifically and in detail with reference to the drawings.
Various shapes of the liquid target for the spallation neutron source have been proposed so far. Some examples are shown in FIGS.
[0015]
The common place for these liquid targets is that the target container 1 has an inlet 2 and an outlet 3 for liquid metal, and a recirculation flow of the fluid and a stagnation region of the flow occur, resulting in a partial temperature rise (hot spot). The distribution rectifying plate 5 is arranged in the target container 1 in order to prevent the occurrence of this. A portion where the liquid metal flowing into the target container 1 from the inlet 2 is reversed to the outlet 3 side is the target portion 4 where a charged particle beam is irradiated as indicated by a thick arrow.
[0016]
In the liquid target shown in FIG. 1, three distribution rectifying plates 5 are arranged symmetrically inside the target portion 4 of the target container 1. The liquid target shown in FIG. 2 extends from a hollow wall that partitions the inlet 2 and the outlet 3 of the target container 1, and has a distribution rectifying plate 5 with slits arranged symmetrically inside the target portion 4. Yes. Furthermore, the liquid target shown in FIG. 3 has a double-tube structure for the target container 1, the outer peripheral side is the inlet 2, the inner peripheral side is the outlet 3, and the inner pipe that partitions the inlet 2 and outlet 3 is distributed and rectified. The plate 5 is used.
[0017]
As shown in FIGS. 4 and 5, the distribution rectifying plate 5 is basically plate-shaped, and the inside of the distribution rectifying plate 5 is hollow, and a hollow protrusion 8 is formed on a part of the outer surface. At least the protrusions 8 adjacent in the front-rear direction with respect to the flow direction of the liquid metal indicated by arrows in FIG. 4 are arranged so as to be shifted in a direction perpendicular to the flow direction of the liquid metal. In the illustrated example, all the three protrusions 8, 8... Are arranged so as not to overlap each other in the direction in which the liquid metal flows, that is, the protrusions 8, 8,. .
[0018]
The base side of the protrusion 8 has a flat shape or a streamline shape that is long in the direction of the liquid metal flow indicated by an arrow in FIG. For example, an ellipse having a major axis in the direction of the flow of the liquid metal. On the other hand, the apex of the protrusion 8 is circular and narrowed to a weight. These protrusions 8 are therefore irregular elliptical cones and cones. Therefore, although the projection 8 is longer flat in the direction of the overall liquid metal flow, the tip is small volumes circular.
[0019]
The inside of the hollow distribution rectifying plate 5 communicates with the tip of the conical protrusion 8, and the sheath type thermocouple 6 is passed from the inside of the distribution rectifying plate 5 to the tip of the protrusion 8. Then, a temperature measuring point 7 where the tips of the pair of conductive wires of the sheath type thermocouple 6 are joined is arranged at the tip of the protrusion 8, and the tip of the protrusion 8 is sealed together with the temperature measuring point 7 by welding or the like. In FIG. 5, the lead wire side of the sheath type thermocouple 6 is omitted.
[0020]
In this way, the temperature measuring point 7 of the sheath type thermocouple 6 protrudes from the surface of the distribution rectifying plate 5 into the flow of the liquid metal, and the distribution rectifying plate 5 itself is used as a liquid target temperature measurement channel. That is, the distribution rectifying plate 5 in which the temperature measuring point 7 of the sheathed thermocouple 6 is sealed at the apex of the protrusion 8 is disposed inside the target portion 4 of the target container 1 as shown in FIGS. The temperature of the liquid metal flowing through the target portion 4 of the container 1 is measured.
[0021]
6 and 7 show a distribution rectifying plate 5 according to another embodiment of the present invention. The basic shape of the distribution rectifying plate 5 is plate-like, and they receive external force due to the flow of liquid metal. Therefore, when the distribution rectifying plate 5 cannot be made hollow for reasons such as strength, the hollow channel plate 10 is attached to all or a part of the surface of the distribution rectifying plate 5. The sheath type thermocouple 6 is passed from the inside of the channel plate 10 to the tip of the protrusion 8. Then, a temperature measuring point 7 where the tips of the pair of conductive wires of the sheath type thermocouple 6 are joined is arranged at the tip of the protrusion 8, and the tip of the protrusion 8 is sealed together with the temperature measuring point 7 by welding or the like. Also in FIG. 7, the lead wire side of the sheath type thermocouple 6 is omitted.
[0022]
In this way, the temperature measuring point 7 of the sheath type thermocouple 6 protrudes from the surface of the distribution rectifying plate 5 into the flow of the liquid metal, and the distribution rectifying plate 5 is used as a liquid target temperature measurement channel. Such a distribution rectifying plate 5 is disposed inside the target portion 4 of the target container 1 as shown in FIGS. 1 to 3, and the temperature of the liquid metal is measured.
[0023]
【The invention's effect】
As described above, in the liquid target temperature measurement channel according to the present invention, by attaching it to the target container 1 for generating spallation neutrons, the flow of the liquid metal flowing in the target container 1 is greatly affected. In addition, the temperature of the liquid metal flowing in the target container 1 can be measured with good responsiveness. Therefore, the temperature of the liquid metal generated when the charged metal beam is irradiated onto the liquid metal in the target container 1 can be measured, and engineering data such as the generated neutron intensity and the heat removal performance of the liquid target structure can be acquired.
[Brief description of the drawings]
FIG. 1 is a schematic longitudinal side view showing an example of a target container using a liquid target temperature measurement channel according to an embodiment of the present invention.
FIG. 2 is a schematic longitudinal side view showing another example of a target container using a liquid target temperature measurement channel according to an embodiment of the present invention.
FIG. 3 is a schematic longitudinal sectional side view showing another example of the target container using the liquid target temperature measurement channel according to the embodiment of the present invention.
FIG. 4 is a schematic plan view showing a liquid target temperature measurement channel according to an embodiment of the present invention.
5 is a cross-sectional view taken along line AA in FIG.
FIG. 6 is a schematic plan view showing a liquid target temperature measurement channel according to another embodiment of the present invention.
7 is a cross-sectional view taken along line BB in FIG.
[Explanation of symbols]
1 Target container 5 Distribution rectifying plate 6 Sheath type thermocouple 7 Temperature measuring point of sheath type thermocouple 8 Projection of distribution rectifying plate

Claims (3)

The liquid metal flowing in the target container (1) is irradiated with a charged particle beam and used for a liquid target that generates neutrons from the liquid metal by nuclear fragmentation. The temperature of the liquid metal flowing in the target container (1) is adjusted. In the liquid target temperature measurement channel to be measured, the distribution rectifying plate (5), which is arranged in the target container (1) and adjusts the flow of the liquid metal flowing in the target container (1), is entirely or partially hollow. In addition, a hollow spindle-shaped projection (8) is provided on the surface, and the temperature measuring point (7) at the tip of the sheath-type thermocouple (6) is provided from the inside of the distribution rectifying plate (5) to the projection (8). The temperature measuring point (7) of the sheath type thermocouple (6) protrudes from the surface of the distribution rectifying plate (5) by leading to the tip and sealing the temperature measuring point (7) with the tip of the protrusion (8). It is characterized by having arranged Liquid target for temperature measurement channel. The base side of the rising portion of the protrusion (8) has a flat shape or a streamline shape that is long in the direction of the liquid metal flow, and the temperature measuring point (7) of the sheath type thermocouple (6) is sealed. The liquid target temperature measurement channel according to claim 1, wherein the apex side has a conical shape.   A plurality of projections (8) are provided on the surface of the distribution rectifying plate (5), and those projections (8) adjacent to the front and rear in the flow direction of the liquid metal are perpendicular to the flow of the liquid metal. The liquid target temperature measurement channel according to claim 1, wherein the channel is used for shifting the liquid target temperature.

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