JPS61142635A - Vapor cooling acceleration apparatus - Google Patents

Abstract

PURPOSE:To prevent damage of nuclear fusion apparatus by suppressing boiling surface temperature to the specified temperature or less with the form of boiling at the high load heat receiving surface which becomes higher than the draining point of cooling liquid defined as the pseudo nuclear boiling by the forced convection of cooling liquid. CONSTITUTION:Many fin-shaped boiling surfaces 2 are formed in the heat radiating side of the heat receiving surface 1 which receives generated heat load such as cystron and a flowing path 7 is formed by placing in contact the internal wall 3 of the cooling liquid tank 6 with the heat receiving surface 1, particularly the heat receiving surface 1a which receives the high thermal load. The cooling water is forced to flow into the narrow path 7 through the lower cooling tank 8 and the cooling water is quided to the upper cooling tank 9 under the condition of pseudo uncleara boiling as the cooling water defined as the high speed two-phase flow of forcibly convected gas and liquid by volume expansion with reduction of area and vaporization. The cooling liquid is further processed with a gas-liquid separation apparatus 15, etc. and is then circulated by a pump 12. Therefore, since the film boiling condition is not generated in the cooling water, high load cooling can processed with a low temperature rise by suppressing generation of draining point.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a boiling cooling acceleration device for boiling and cooling a high-load heat receiving surface such as a cryostron used in a nuclear fusion device.

[Technical background of the invention and its problems]

Heavy electrical equipment, nuclear fusion equipment, etc. (e.g. klystron, etc.)
In recent years, there has been a remarkable trend towards high output and miniaturization, and even in boiling cooling of the high-load heat receiving surface of these devices, the heat load on the heat receiving surface is the maximum flux value (extraction point) of normal water nucleate boiling1,5 ~2. It can reach several times OXIO' W/d. In this way, in boiling cooling of a high-load heat-receiving surface,
In the heat flux region beyond the extraction point, the form of boiling at the heat receiving surface becomes a film swell covered with a layer of steam, and therefore the boiling surface temperature reaches 500°C to 100'O"C, causing the boiling surface and The heat-receiving surface connected to this boiling surface causes melting of the respective components, which in turn causes damage to the equipment.

[Purpose of the invention]

The present invention converts the boiling form of the high-load heat-receiving surface, which is above the coolant drainage point, into pseudo-nucleate boiling by forced convection of the coolant.
The purpose is to prevent damage to equipment by suppressing the boiling surface temperature below a predetermined temperature.

[Summary of the invention]

In order to achieve the above object, the present invention includes a flow path formed by a plurality of fins provided on the heat receiving surface so as to be in contact with each other from the inner circumferential side, and a device for supplying cooling water to this flow path. It is characterized by having

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. This will be explained with reference to Figure J3. In Figure 1, 1 is a heat receiving surface that receives the heat load generated by heavy electrical equipment such as klystrons and nuclear fusion equipment from the inner side, and the heat radiating side of this heat receiving surface 1 has multiple grooves in the same direction. A fin-shaped boiling surface 2 is formed. Further, a cooling liquid tank 6 having an outlet 4 at the upper part and an inlet 5 at the lower part is installed so that the inner wall 3 of the heat receiving surface 1 is in contact with the outer peripheral side of the high load heat receiving surface 1m which receives particularly high heat loads. Also, as shown in Figures 2 and 3;
is a flow path, and this flow path 7 is formed by bringing the high-load heat receiving surface 1m on which the boiling surface 2 is formed into contact with the inner wall 3. Further, a lower cooling liquid tank 8 communicating with the flow path 7 is installed in the lower part of the cooling liquid tank 6, and an upper cooling liquid tank 9 communicating with the flow path 7 is installed in the upper part of the cooling liquid tank 6 (2). Furthermore, a main stream outlet 10 is provided at the upper part of the upper cooling liquid tank 9, and a main stream inlet 11 is provided at the lower part of the lower cooling liquid tank 8. is provided with a pump 12, and this pump 12, the main stream inlet 11 and the inlet 5 are connected to a flow control valve 1, respectively.
A connecting pipe 14 is connected via 3a, 13b (for example, a solenoid valve). The main stream outlet 10 and the outlet 4 are connected to the gas-liquid separation device 15 through an outlet pipe 18, respectively. It is connected to a condenser 16, a radiator 17, and the pump 12.

Next, the effect will be explained. The cooling water discharged from the pump 12 flows into the lower cooling tank 8 and then into the narrow channel 7. In this flow path 7, the cooling water rises to the high-load heat-receiving surface (1a) receiving heat, and a part of it vaporizes and becomes water vapor. Further &: Since the high load heat receiving surface 1m is in contact with the inner wall 3, heat from the high load heat receiving surface 1g is also transferred to this inner wall 3 due to heat conduction, so some of the cooling water is also transferred from this inner wall 3. In addition, in the flow path 7, the cooling water undergoes a reduction in area and volume expansion due to vaporization of the cooling water: = faster forced convection gas-liquid 2
The liquid becomes a phase flow and flows into the upper cooling liquid tank 9 in a state of pseudo nucleate boiling. In the upper cooling liquid tank 9, cooling water is supplied to the heat receiving surface 1.
A boiling cooling state occurs under low-speed forced convection conditions. In this upper cooling liquid tank 9, since the cooling water has a low heat load, it does not flow in a film boiling state but in a nucleate boiling state. Further, the gas-liquid two-phase cooling water flowing out from the main stream outlet 10 of the upper cooling liquid tank 9 is separated into steam and boiling water in the gas-liquid separator 15, and further, this steam is liquefied in the condenser 16, and then the radiator 17, and the boiling water is directly led to the radiator 17, where the heat is radiated and then the boiling water is led to the pump 12 again. On the other hand, the cooling water flowing into the cooling liquid tank 6 from the inlet 5 via the flow rate control valve 13 cools the inner wall 3 forming the flow path 7, and then flows from the outlet 4 via the outlet pipe 18 to the gas-liquid separation device as described above. 15, the condenser 16, the radiator 17, and the pump 12. In this way, the flow path 7 is provided in a part where a high heat load can be applied.1 This creates a high-speed forced convection condition that blows away the air bubbles generated in the flow path 77, and further cools the cooling water from the outer circumference of this flow path. Since the structure is designed to cool the cooling water, film boiling does not occur and the cooling water can reach the high heat flux region while maintaining a pseudo nucleate boiling state. Therefore, as shown in Figure @4, the maximum value A (extraction point) observed at pool boiling B is not observed at forced convection boiling 131c and D, and a phenomenon in which the boiling surface temperature rises dramatically does not occur. Note that C indicates a boiling characteristic curve due to forced convection boiling at a low flow rate, and D indicates a boiling characteristic curve due to forced convection boiling at a high flow rate.

Since no extraction points occur in this way, according to this embodiment, even if the heat flux increases, the boiling surface temperature will rise continuously, making it possible to handle high heat loads with a low temperature difference that could not be achieved conventionally. becomes. In addition, in the above embodiment, since the cooling water is installed only in the high-load heat receiving section, which is the cooling water flow path, it is possible to prevent the adverse effects caused by the increase in pressure loss in the flow path due to the occurrence of increasing voids.

〔Effect of the invention〕

According to the present invention, high-load cooling can be handled with extremely low temperature rise values, and the occurrence of extraction points can be suppressed to prevent damage to equipment.

[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 an embodiment of the present invention.
Figure 3 is a perspective view of the main part of the figure, Figure 3 is a sectional view taken along I-■ in Figure 2, Figure 4
The figure is a boiling characteristic curve diagram showing the relationship between heat flux and heating surface temperature-saturation temperature. 1a... ten thousand load heat receiving surface, 2... boiling surface (fin), 3... inner wall, 6... cooling liquid tank,
7...Flow path. Agent Patent Attorney Kensuke Chika (1 idiot) 1st ml

Claims (1)

[Claims] A heat receiving surface that receives a high load from the inner circumferential side, a cooling liquid tank arranged on the outer circumferential side of this heat receiving surface, an inner wall of this cooling tank, and a plurality of fins provided on the heat receiving surface so as to be in contact with this inner wall. What is claimed is: 1. A boiling cooling promotion device comprising: a flow path formed by the above, and a device for supplying cooling water to the flow path.