JPH0229436Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a support device for heat transfer tubes in a high-temperature heat exchanger.

[Conventional technology]

In recent years, heat generated in high-temperature heating furnaces (e.g., nuclear reactors) is extracted using a heat medium such as helium gas, and this is exchanged with a secondary heat medium in an intermediate heat exchanger.
The heat obtained here is used to generate electricity.

An example of the structure of a heat exchanger used in this high-temperature heating furnace will be explained with reference to FIG. A primary heat medium inlet 2 is formed for introducing a high temperature primary heat medium obtained from a heat exchanger (not shown) into the container 1. The high-temperature primary heat medium introduced into the container 1 from the primary heat medium inlet 2 rises between the helical coils 3 in the container 1 in which a large number of helical coils 3, which are heat transfer tubes, are provided. The primary heat medium that has reached the top is
The heat medium flows down the flow path 5 formed between the inner surface of the container 1 and the outer surface of the partition wall 4, and is finally discharged from the primary side heat medium outlet 6 formed at the lower side of the container 1, and is returned to the high temperature heating furnace. It is about to be transferred.

On the other hand, the helical coil 3 is formed in a spiral shape around a center pipe 7 provided along the axial direction of the central part of the container 1, and one end of the helical coil 3
is connected to the secondary heat medium inlet 8 formed at the uppermost end of the center pipe 7 via an upper connecting pipe 9 and an inlet header 10, and the other end is connected to the lower header 16 ( 3), and therefore, the low-temperature secondary heat medium introduced from the secondary heat medium inlet 8 is connected to the upper connecting pipe 9.
After passing through the helical coil 3, it exchanges heat with the primary heat medium while flowing down inside the helical coil 3, and then passes through the center pipe 7.
It flows into the inner lower end, rises inside, and is transferred to other devices from the secondary heat medium outlet 12 at the upper end. In the figure, reference numeral 13 indicates a heat insulating material provided around the outer periphery of the container 1, reference numeral 14 indicates a heat insulating material provided on the inner surface of the partition wall 4, and reference numeral 15 indicates tube support beams provided radially.

In the heat exchanger described above, the helical coil 3
As shown in FIG. 2, each layer of the helical coil 3 is suspended from a tube support beam 15 and is supported by a ladder-like coil support 17 extending in the vertical direction. In order to absorb thermal expansion, an unsupported portion is left at the bottom of the helical coil 3 for a required number of turns.

Here, the lower part of the helical coil 3 is about 950
℃, and the strength of metal materials decreases significantly at high temperatures, so the lower part of the helical coil 3 needs to be strong enough to not only withstand the pressure of the heat medium but also withstand its own gravity. becomes. For that reason,
Conventionally, this problem has been solved by making the cross-sectional shape of the helical coil 3 large enough to exhibit sufficient strength.

[Problem that the invention attempts to solve]

However, as heat exchangers have become larger in recent years, supporting the helical coil 3 has become essential, and it has been considered to extend the coil support 17 to the bottom of the helical coil 3 to support it. However, as mentioned above, the coil support 1
Since the difference in thermal expansion in the vertical direction of 7 becomes larger toward the bottom, there is a risk that thermal stress will be concentrated on the support portion and cause damage.

The present invention was created in view of the above-mentioned circumstances, and aims to provide a support device for heat exchanger tubes that can support the lower part of a helical coil with an extremely simple configuration without concentrating thermal stress. .

[Means for solving problems]

The present invention supports the heat exchanger tubes from the lowest stage of each helical coil layer except for the required stage by a coil support that is suspended from above and extends in the vertical direction, and furthermore, the heat exchanger tubes of the helical coil layer are This invention relates to a support device for heat exchanger tubes, characterized in that heat exchanger tubes from the first stage to the required stage are held in a pair with each other by heat exchanger tube support fittings.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.
FIG. 3 is an explanatory diagram showing a state in which the present invention is implemented, and FIG. 4 is a view taken along the line A--A of the embodiment.
Components in the drawings that are the same as those in FIG. 1 are designated by the same reference numerals.

From the lower end of each layer of the helical coil 3, heat exchanger tubes 18 in required stages (three stages in the figure) are held between a pair of opposing heat exchanger tube support fittings 19, 19.
are joined by bolts 20.

In addition, 21 is a heat transfer accelerator plate, and the thickness of the combined support metal fittings 19, 19 is equal to that of the heat transfer accelerator plates 21, 2.
It is set equal to 〓 for 1 period.

Next, the action will be explained.

The temperature of the primary heating medium reaching the lower connecting pipe 11 is approximately 950°C, and as it passes outside the helical coil 3, it exchanges heat with the secondary heating medium inside the helical coil 3, and its temperature decreases. , there is a temperature drop of about 50° C. when passing near the third stage of the heat exchanger tubes 18. As mentioned above, the strength of metal materials rapidly decreases as the temperature increases. For example, nickel alloy has an allowable stress of 0.5Kg/mm ² at 900℃, but it decreases to 0.2Kg/mm ² at 950℃. becomes. Therefore, even if there is a slight temperature drop, it exhibits strength that is more than capable of resisting its own gravity and pressure. Therefore, the heat exchanger tube support fitting 19,
At 19, the heat exchanger tubes 18 from the lowest heat exchanger tube 18 to the heat exchanger tube 18 with sufficient strength are sandwiched in one body and the heat exchanger tubes 18 support each other.

Furthermore, the lower end of the heat transfer accelerator plate 21 may be deformed due to thermal distortion, and the spacing may change, but the two heat transfer tube support fittings 19, 19 exert a spacing retaining function to prevent misalignment of the spacing. do.

Note that the shape of the heat exchanger tube support fitting is not limited to the above-mentioned embodiment, and it is sufficient that the heat exchanger tubes of the required stages can be held in one body.

[Effect of idea]

As mentioned above, the following excellent effects can be achieved by the invention.

(i) The lower part of the helical coil can be effectively supported with an extremely simple structure without concentrating thermal stress.

(ii) For those with heat transfer accelerator plates, it is possible to prevent deformation of the heat transfer accelerator plates, maintain the spacing between the heat transfer accelerator plates, and equalize the heat transfer performance of each layer of the helical coil.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view showing one example of a heat exchanger, Figure 2
The figure is an explanatory diagram of the coil support, FIG. 3 is an explanatory diagram of the state in which the present invention is implemented, and FIG. 4 is a view taken along the line A--A in FIG. 3. 3 is a helical coil, 18 is a heat exchanger tube, 19 is a heat exchanger tube support fitting, and 20 is a bolt.

Claims (1)

[Scope of utility model registration request] The heat exchanger tubes in the helical coil layers except for the lowest stage to the required stage are supported by a coil support that is suspended from above and extends in the vertical direction, and further the heat exchanger tubes are supported from the lowest stage to the required stage in each helical coil layer. A heat exchanger tube support device characterized in that heat exchanger tubes are integrally held together by heat exchanger tube support fittings.