JPS613999A - Shell and tube type heat exchanger - Google Patents

Abstract

PURPOSE:To permit to regulate flow of fluid without enlarging the diameter of an outer cylinder for the heat exchanger by a method wherein guide vanes, guiding the fluid, outside of the tube, to inflow windows from a nozzle, are provided in an annular space between the outer cyinder and an inner cylinder to form a spiral flow path. CONSTITUTION:The guide vanes 10, attached spirally to the outer peripheral surface of the inner cylinder 3 for the shell and tube type heat exchanger, change the ununiform flow directions of primary series sodium in the annular space 8, which flowed into the outer cylinder 2 from the inlet nozzle 1, and regulate the flow thereof into spiral flow, therefore, stagnant area is reduced and a flow amount distribution in the annular space 8 is uniformed. Thus, the stagnant area, caused by the separation or the like of the flow, is reduced compared with the flow regulating system utilizing a multitude of holes and, accordingly, the flow of fluid may by regulated and the manufacturing cost of the heat exchanger may be reduced without reducing the pressure in the space 8 by enlarging the diameter of the outer cylinder 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has an outer shell in which an extratubular fluid nozzle is integrally formed, and is arranged approximately coaxially within the outer shell, and has a nozzle for inflow and outflow of the extratubular fluid at both ends. The present invention relates to an improvement of a shell-and-tube heat exchanger having an inner shell in which a window is formed and a bundle of heat transfer tubes extending longitudinally within the inner shell.

The shell-and-tube heat exchanger (intermediate heat exchanger) used in conventional fast breeder reactors is explained using Figure 4. (1) is the primary system sodium (extratubular fluid) nozzle, (2) 2 is an outer shell, and (3) is an inner shell that is disposed substantially coaxially within the outer shell (2) and has a primary sodium inflow window (4) formed at its upper end.

Note that there is a window for the primary sodium outflow at the lower end of the inner shell (3), but it is not shown completely. Although (5) is not specifically shown, a bundle of heat exchanger tubes is disposed extending in the longitudinal direction within the inner shell (3), and (8) is a bundle of heat exchanger tubes disposed in the inner shell (2) and the inner shell (3). (9) is the annular space between (
8) A porous baffle plate installed in the upper part of the inner shell allows primary sodium (Al) to flow from the inlet nozzle (1) into the outer shell (2), and then between the outer shell (2) and the inner shell (3). ), and then flows into the heat transfer tube bundle (5) as an extratubular fluid through the inlet window (4) provided at the upper end of the inner shell (3). , exchanges heat with the secondary sodium flowing inside the heat transfer tube.Then, the primary sodium (
A) flows out from the outflow window provided at the lower end of the inner shell (3) into the annular space (8), and further flows out of the heat exchanger through a primary system sodium outflow nozzle (not shown). . Note 1
The secondary system is a system through which sodium (coolant) directly cools the core, and the secondary system is a system in which the core is cooled via the sodium in the primary system.

In the shell-and-tube heat exchanger, the outer shell (2)
and the inner shell (3) from the annular space (8) to the heat exchanger tube bundle (5
) There is a problem of how to equalize the flow rate distribution in the circumferential direction of the inner shell (3) of the primary sodium (gradient) flowing as an extratubular fluid into the inner shell (3).If the flow rate in the circumferential direction in the inner shell (3) If the distribution is uneven, a biased flow will occur in the primary sodium around the heat exchanger tube bundle (5), and this drift will cause the temperature distribution in the circumferential direction of the heat exchanger tube bundle (5) to become uneven. If the heat transfer performance of the shell-and-tube heat exchanger deteriorates and the temperature distribution is noticeably uneven, buckling will occur in the heat transfer tubes due to the difference in thermal expansion between the heat transfer tubes.One countermeasure for this problem is To,
Annular space (8) Il'' is required to install a multi-hole rectifier plate (9) (6, the rectifier plate (9) is a primary system in one place) IJ
The primary sodium system enters the outer shell (2) from the aluminum-containing nozzle (1) and flows into the inner shell (3) from the entire upper circumference of the inner shell (3). (3) The flow distribution in the circumferential direction within the tube is made uniform. Also, the same rectifier plate (
In addition to 9), the opening area of the inflow window (4) at the upper end of the inner shell (3) may be varied along the circumferential direction to provide a rectifying effect to the inflow window (4). When these measures are taken, an increase in pressure loss cannot be avoided in shell-and-tube heat exchangers. This increase in pressure loss can be solved by increasing the diameter of only the outer shell (2) and increasing the flow passage cross-sectional area of the annular space (8), but in that case, shell-and-tube type Heat exchangers have become larger,
There is a problem of high cost.

The present invention addresses the above-mentioned problems, and includes an outer shell in which an extra-tubular fluid nozzle is integrally formed, a nozzle for extra-tubular fluid disposed approximately coaxially within the outer shell, and a nozzle for extra-tubular fluid provided at both ends. In a shell-and-tube heat exchanger, the shell-and-tube heat exchanger includes an inner shell in which an inlet/outlet window is formed, and a heat transfer tube bundle arranged longitudinally within the inner shell, wherein the outer shell and the inner shell A shell-and-tube heat exchanger characterized in that a guide vane is provided in an annular space between the tubes to guide the flow from the nozzle to the inflow window to form a spiral flow path. The target area is to increase the diameter of the outer shell without reducing pressure loss.
The object of the present invention is to provide an improved shell-and-tube heat exchanger that can rectify flow and reduce manufacturing costs.

Next, the shell-and-tube heat exchanger of the present invention will be explained with reference to the embodiments shown in FIGS. 1 to 3.
1) is the primary system sodium (extratubular fluid) user nozzle, (
2) is an outer shell, (3) is an inner shell which is arranged almost coaxially within the same external body (2) and has windows +41+611 formed at the upper and lower ends for the inflow and outflow of primary sodium, and (5) is an inner shell. Same inner body (3
), (7) is a primary sodium discharge nozzle, and (8) is the outer shell (2).
: The annular space between the inner shell (3) and the inner shell (3) shown in Figures 2 and 3.
1 [is the guide vane that is the most characteristic feature of the present invention, and the guide vane q [ is the guide vane q] for the primary sodium (Al) flow in the circumferential direction from the primary sodium nozzle (1) into the outer shell (2). The guide vane C1 (l
The width of the annular space (8) may be equal to the width (L) of the annular space (8) (see Fig. 3) or may not be equal (see Fig. 2). In addition, the number and length of the guide vanes (11 are not limited to the illustrated example, but these conditions are determined by the flow rate of the primary sodium system, etc.).
A current plate may be provided or the opening area of the inflow window (4) may be changed.

Next, the operation of the shell and tube type heat exchanger will be explained. The guide vanes (101) are used to spirally change the direction of the non-uniform flow (vector) of primary sodium and rectify the flow, reducing the stagnant area and making the flow distribution in the annular space (8) uniform. be converted into

As described above, in the case of the guide vane QO1 of the present invention, the stagnant region caused by flow separation is reduced compared to the porous rectifying plate system, so the diameter of the outer body (2) is increased to reduce pressure loss. Even if you do not try to reduce it, you can rectify it,
It has the effect of reducing production costs.

All the embodiments of the present invention have been described above, but of course the present invention is not limited to these embodiments, and various design changes can be made without departing from the spirit of the invention. .

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional side view showing one embodiment of a shell-and-tube heat exchanger according to the present invention, Figs. It is a perspective view showing a tube type heat exchanger. (11(7)...Nozzle for extratubular fluid, (2)...Outer shell, (3)...Inner shell, (4)(6)...Outflow/inflow window, (5)...・・Heat transfer tube bundle, (end・・annular space, 001・
・Guide blade. Sub-Agent Patent Attorney Shige Okamoto 3 other persons Figure 1 A Figure 3 Aq

Claims (1)

[Claims] an outer shell having an integrally formed nozzle for extra-tubular fluid; an inner shell disposed substantially coaxially within the outer shell and having windows for inflow and outflow of the extra-tubular fluid formed at both ends; In a shell-and-tube heat exchanger having a bundle of heat transfer tubes extending longitudinally within the inner shell, an extratubular fluid is introduced into an annular space between the outer shell and the inner shell through the nozzle. 1. A shell-and-tube heat exchanger, characterized in that a spiral flow path is formed by disposing guide vanes that guide the flow from the inflow window to the inflow window.