JPH0656224B2 - Cooling structure of the concrete wall penetration part of the high temperature pipe insulation tube - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cooling structure for a concrete wall penetrating portion of a high temperature piping heat insulating cylinder in a nuclear power plant.

[Prior Art and Problems Thereof] A high temperature pipe through which liquid sodium as a coolant flows in both the primary cooling system and the secondary cooling system of a nuclear power plant is enclosed by a heat insulating cylinder. Since this high-temperature pipe heat insulation tube is pierced through the concrete wall, which is a partition between the cells, the through hole portion of the concrete wall is heated by the heat radiated from the high-temperature pipe heat insulation tube. Therefore, in the past,
As shown in the figure, the blower 5 blows or cools the through-hole 4 of the concrete wall 3 through which the heat-retaining cylinder 2 having the heat-retaining material such as Rockfine, which encloses the high-temperature pipe 1 in which liquid sodium at 550 ° C flows, is blown or cooled by the blower 5. A water cooling pipe 6 is buried near the inner peripheral surface of the hole 4, and cooling water is circulated to cool the periphery of the through hole 4. Reference numeral 7 in the drawing denotes a bellows that seals the space between the heat insulating cylinder 2 and the through hole 4.

By the way, the above cooling method gives an excessive temperature distribution in the length direction of the high temperature pipe 1, and particularly in the high temperature pipe 1 having an electric heater for preheating for preventing solidification of the internal fluid, It was difficult to set the capacity of the heater due to the excessive temperature distribution in the above, and it was difficult to preheat with a balance. Therefore, there is a portion where the gas in the gap with the through hole 4 rises abnormally due to the heat dissipated from the surface of the heat insulating cylinder 2, and the temperature of the concrete near the inner peripheral surface of the through hole 4 is 100%.
There were parts where the soundness of concrete was lost when the temperature exceeded ℃.

[Object of the Invention] The present invention has been made to solve the above problems, and an object of the present invention is to provide a cooling structure capable of maintaining the soundness of concrete in a concrete wall penetrating portion of a high temperature pipe heat insulating tube. It is what

[Means for Solving Problems] The cooling structure of the concrete wall penetrating portion of the high-temperature pipe heat-insulating cylinder according to the present invention for solving the above-mentioned problems is provided in the through-hole of the concrete wall which penetrates the high-temperature pipe heat-insulating cylinder. An outer plate is provided horizontally on the outer surface of the heat retaining cylinder to vertically divide the gap between the heat retaining cylinder and the through hole, and the bellows side, which seals between the heat retaining cylinder and the peripheral edge of the through hole, communicates with each other. A turn passage is formed, and a stack is provided on the entrance / exit side of the U-turn passage.

[Operation] The cooling structure of the concrete wall penetrating portion of the high-temperature pipe heat insulating tube having the above-described configuration has a U-turn due to a rise in gas in the gap between the through hole of the concrete wall due to heat dissipated from the surface of the heat insulating tube. As a result of gas flow due to natural convection in the passage, the temperature-rising gas exits the U-turn passage and is discharged from the stack, and the normal-temperature gas continuously flows into the U-turn passage. The temperature of the concrete near the inner surface of the concrete does not exceed 100 ° C, and therefore the soundness of the concrete is maintained.

[Embodiment] An embodiment of the cooling structure for the concrete wall penetrating portion of the high temperature pipe heat insulating cylinder according to the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, the same reference numerals as those in FIG. 3 indicate the same items, and the description thereof will be omitted. The exterior plate 8 is horizontally fixed to the outer surface of the heat insulating cylinder 2 in the through hole 4 of the concrete wall 3 so as to vertically define a gap between the heat insulating cylinder 2 and the through hole 4 and at the bellows 7 side. A U-turn passage 9 is formed in communication with the outside of the through hole 4. On the entrance side of the U-turn passage 9, that is, on the side opposite to the bellows 7, a shield plate 10 having a vertical cross section is provided at a proper distance from the concrete wall 3, and one end of the exterior plate 8 is connected to the inner surface thereof. The stack 11 is formed. The height of the stack 11 is set to an appropriate height in order to optimize the amount of gas flowing into the U-turn passage 9.

According to the cooling structure for penetrating the concrete wall of the embodiment configured as described above, the gas in the gap between the through hole 4 of the concrete wall 3 is heated by the heat dissipated from the surface of the heat insulating cylinder 2 enclosing the high temperature pipe 1. However, due to the temperature rise of this gas, a gas flow occurs in the U-turn passage 9 by natural convection. As a result, the temperature rising gas exits the U-turn passage 9 and is discharged from the upper end of the stack, and the normal-temperature gas continuously flows into the U-turn passage 9 from the lower end of the stack 11. In particular, since the stack 11 is formed on the entrance / exit side of the U-turn passage 9, the draft force of the gas is strong, and therefore the flow velocity of the gas flowing through the U-turn passage 9 is high. Temperature is around 70 ℃, and the stack
Since the temperature of the gas discharged from the upper end of 11 is around 65 ° C, the soundness of concrete is secured.

[Effects of the Invention] As can be seen from the above description, according to the cooling structure for the concrete wall penetrating portion of the high temperature pipe heat insulating tube according to the present invention, the gas in the through hole of the concrete wall is heated by the heat radiated from the heat insulating tube. As a result, natural convection causes a gas flow in the U-turn passage formed in the through-hole, and the room-temperature gas continuously flows into and out of the U-turn passage. The temperature is kept below 100 ° C, the soundness of the concrete is maintained, and there is no need to blast-cool with a blower or to bury a water-cooling pipe near the inner peripheral surface of the through hole unlike the conventional case.

Also, the amount of gas flowing into the U-turn passage can be changed by adjusting the height of the stack on the inlet / outlet side of the U-turn passage, so that the temperature of the concrete near the inner peripheral surface of the through hole can be suppressed to a desired temperature. Is possible.

Furthermore, in high temperature piping with an electric heater for preheating,
It is possible to match the temperature distribution in the lengthwise direction with the high temperature pipes other than the wall penetrating portion, and it is easy to set the capacity of the electric heater.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a cooling structure for a concrete wall penetrating portion of a high temperature pipe heat insulating cylinder according to the present invention, FIG. 2 is an AA sectional view of FIG. 1, and FIG. 3 is a conventional high temperature. It is a longitudinal cross-sectional view which shows the cooling method of the concrete wall penetration part of a pipe heat insulation cylinder. DESCRIPTION OF SYMBOLS 1 ... High temperature piping, 2 ... Heat insulation cylinder 3 ... Concrete wall, 4 ... Through hole 7 ... Bellows, 8 ... Exterior board 9 ... U turn passageway, 11 ... Stack

Claims (1)

[Claims] 1. Inside a through hole of a concrete wall penetrating a high temperature pipe heat insulation tube, an outer plate is provided horizontally on the outer surface of the heat insulation tube to vertically define a gap between the heat insulation tube and the through hole. Cooling of a high temperature pipe insulation tube through a concrete wall where a U-turn passage is formed by communicating between the insulation tube and the periphery of the through hole on the bellows side that is closed and a stack is provided at the entrance and exit side of the U-turn passage. Construction.