JPS5844914B2 - Convection prevention device in pipe group duct - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing convection in a duct in which a plurality of pipes containing high-temperature fluid are housed and kept warm in a duct made of a heat insulating material.

For example, in a group of pipes containing high-temperature fluid, such as in a nuclear power plant, as shown in FIGS. A plurality of partition plates 3 are installed at appropriate intervals in the axial direction of the piping 1, and duct support frames 4 are provided at the corners of the duct 2, in order to accommodate the pipes and prevent convection within the duct 2. ing.

A hole 5 is formed in the partition plate 3 at a location through which the pipe 1 is inserted, and a gap g is formed between the partition plate 3 and the outer periphery of the pipe 1.

In this conventional device, if the diameter of the hole 5 is made large and the gap g is made small, the original function of the partition plate 3 that partitions the inside of the duct cannot be achieved, whereas if the diameter of the hole 5 is made small and the gap g
If it is small, thermal displacement of the piping 1 due to temperature changes of the high-temperature fluid due to plant operation, stoppage, etc. will be restricted, which may lead to damage to the piping.

Therefore, the conventional device cannot be applied to a group of pipes with a large thermal displacement, or where each pipe has a different amount of thermal displacement, and has the disadvantage that it cannot completely seal the axial flow of gas in the duct. .

An object of the present invention is to provide a convection prevention device that can completely seal a group of pipes in the axial direction and does not restrict thermal displacement of the pipes.

In the present invention, the shield plate attached to each pipe closes the space between the shield plates and between the inner surface of the duct and the shield plate, and the plate surfaces are brought into contact with each other so that the shield plate can move phantomly. By arranging two sets of combination bodies consisting of a plurality of support plates combined with each other and fixed to a duct support frame with an interval in the axial direction, and filling a heat insulating material between the two combination bodies. It is characterized by comprising a convection prevention device.

The details of the present invention will be explained below with reference to embodiments shown in FIGS. 3 to 7.

A shield plate 6 is attached to each pipe 1 through which high-temperature fluid flows, and in this embodiment, as shown in FIG.
A notch 6b is provided from a to the outer circumference.

Various shapes can be adopted as the overall shape of this shield plate depending on the piping arrangement structure, but when the piping is arranged horizontally and vertically as in this actual case, the shield plate described below can be used. A rectangular shape is preferable in terms of its effect.

In this embodiment, a cut 6b is formed in the shield plate 6.
The purpose of this is to allow the shield plate to be attached to the piping even after piping 1 has been installed. It can be easily installed by bending the portion 6b left and right, pushing it into the pipe 1 from the side, and returning it to its original position.

In order to facilitate attachment to the piping 1, in addition to this embodiment,
It is also possible to adopt a structure in which the shield plate 6 is divided into a plurality of pieces in the circumferential direction and combined with bolts, etc.

The cut 6b in this embodiment also has the function of absorbing expansion and contraction of the fluid in the pipe 1 due to temperature changes.

In this embodiment, as shown in FIGS. 3 and 4, these shield plates 6 have their upper and lower plate surfaces slidably abutted against each other, and have two shield plates for each pipe.
They are attached one by one at appropriate intervals.

Reference numeral 7 denotes a support plate that supports the shield plate 6 and the heat insulating material 8 filled between the shield plates 6. As shown in FIG. 3 and the inner surface of the duct 2.

In this embodiment, the shield plates 6 adjacent to each other do not overlap on the left and right sides, but overlap in the vertical direction. Therefore, when the support plate 7 is L-shaped and U-shaped long in the vertical direction, It shows about.

These support plates 7 are connected by bolts 11 to upper and lower horizontal support frames 9° 10 horizontally installed between duct support frames 4 provided along the longitudinal direction of the duct 2 to support the duct 2. It is attached with one side slidingly abutting against the peripheral plate surface of the shield plate 6.

FIG. 7A is an exploded perspective view illustrating the attachment relationship of each member.

Note that it is preferable that the heat insulating material 8 is light in weight and flexible in the sense that it allows the movement of the shield plate and maintains the blocking function regardless of the movement, and the shield plate 6 is made of a flexible thin plate. It is preferable to do so in the sense that the thermal displacement of the pipe 1 is not strongly restricted.

In addition to the above, the convection prevention device of the present invention has a structure in which the gap is closed by a shield plate and a support plate, and two sets of relatively movable combinations are arranged at intervals in the longitudinal direction of the pipe. , which has a structure in which a heat insulator is filled between the two, and can more completely prevent natural convection caused by temperature differences within the duct compared to conventional pipes that have a gap around the outer periphery of the pipe.

In addition, the relative displacement structure can absorb the thermal displacement of the piping due to the temperature change of the high-temperature fluid, so there is no risk of excessive stress on the piping. It can also be applied to large tube groups.

In addition, since the structure is such that a shield plate is attached to each pipe and supported by a support plate divided into multiple pieces, it is easier to use in places with narrow spaces or curved parts compared to the conventional one with a single partition plate. Easier installation is possible for certain tube groups.

Furthermore, by attaching a shield plate to the
The local vibration frequency of the piping can be increased, thereby increasing the rigidity of the piping.

[Brief explanation of drawings]

Figure 1A is a cross-sectional view in the short direction of a duct showing a conventional convection prevention device, Figure 1B is a cross-sectional view in the longitudinal direction of the duct, and Figure 2 is a cross-sectional view in the longitudinal direction of the duct.
FIG. 2 is a partially enlarged sectional view of FIG. 3 to 7 show an embodiment of the convection prevention device according to the present invention, and FIG. 3 is a sectional view in the short direction of the duct;
Fig. 4 is a sectional view in the longitudinal direction of the duct, Fig. 5A is a front view of the support plate, Fig. 5B is a side view thereof, Fig. 6A is a front view of the shield plate, Fig. 6B is a sectional view thereof, Fig. 7 A is an exploded perspective view illustrating the overall attachment relationship, and B is an explanatory diagram of the folded state when the shield plate is attached. 1... Piping, 2... Duct, 4...
... Duct support frame, 6 ... Shield plate, 7 ... Support plate, 8 ... Heat insulation material, 9,
10...Horizontal support frame, 11...Bolt.

Claims (1)

[Claims] 1. In a pipe group consisting of a plurality of pipes containing high-temperature fluid housed in a duct made of a heat insulating material, a shield plate attached to each pipe, and a shield plate installed between the shield plates or between the shield plates or the duct. 2. Consisting of a plurality of support plates that close the space between the inner surface and the shield plate and are fixed to the duct support frame by bringing the plate surfaces into contact with each other so that the shield plate can move relatively. 1. A convection prevention device in a tube group duct, characterized in that a set of combination bodies are arranged at intervals in the axial direction, and a heat insulating material is filled between the two combination bodies. 2. The pipe group according to claim 1, wherein the shield plate has a hole in the center that fits into the pipe, and a notch extending from the crest hole to the outer periphery of the shield plate. Convection prevention device in the duct.