JPH0446321B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steam generation plant, particularly a steam generation plant such as a fast breeder reactor that uses liquid metallic sodium as a coolant.

In conventional fast breeder reactors, metallic sodium becomes activated when irradiated with neutrons, so the cooling system is generally divided into a primary system and a secondary system, and the heat of the non-activated sodium in the secondary system is used to generate steam. is occurring. In Fig. 1, 1 is a nuclear reactor, and the heat generated here is transferred to an intermediate heat exchanger 3 through a primary system piping 2.
There, it is transferred to a secondary system of non-activated sodium, and is transmitted to a steam generator 5 through a secondary system piping 4, where steam is generated. 6 and 7 are primary system and secondary system circulation pumps, 8 is a steam system piping, and 9 is a water supply pump. The intermediate heat exchanger 3 and the steam generator 5 are installed independently, and are connected by a pipe 4. Since the temperature of the coolant in a fast breeder reactor is high, this piping 4 requires a long route to reduce thermal expansion stress, and requires a considerably large space for installation, including the space for installing the steam generator 5. However, there was a problem in that the cost of both equipment and buildings increased.

The present invention was invented in order to deal with the above-mentioned problems, and its gist is that the shell-and-tube heat exchanger is arranged in the lower part and the steam generator is arranged in the upper part, and is formed integrally. , a central downcomer pipe for extra-tubular fluid of the steam generator and a central downcomer pipe for extra-tubular fluid of the heat exchanger are aligned and connected, and a relative displacement absorbing structure is provided at the connection part, and the steam generator and a steam generation plant, characterized in that the extra-tube fluid of the heat exchanger is circulated by a pump, and the water supplied in the heat transfer tubes installed in the steam generator is heated and evaporated by the extra-tube fluid. .

Since the present invention has the above-mentioned configuration, there is no need for long piping for transferring a heat medium such as a secondary coolant, which was conventionally connected between a heat exchanger and a steam generator. No space is required for piping installation. Furthermore, since the space above the shell and tube heat exchanger can be used to install the steam generator, the installation space for the steam generator can also be saved. Therefore, the buildings that house these heat exchangers, steam generators, piping, etc. have also become smaller.
Steam generation plants can be made cheaper.

The present invention will be specifically described below with reference to an embodiment shown in FIG.

In FIG. 2, 10 is a shell-and-tube type intermediate heat exchanger for exchanging heat between the primary coolant and the secondary coolant, 11 is the heat exchanger tube of the heat exchanger 10, and 12 , 13 are heat exchanger tubes 11, respectively.
14 is a downcomer pipe. The primary coolant heated in the reactor flows from the upper part of the upper tube sheet 12 as shown by the white arrow, passes through the heat transfer tubes 11, exits from below the lower tube sheet 13, and enters the reactor core. return. The secondary coolant comes down the central downcomer pipe 14 from the steam generator 20, which is disposed at the upper part of the heat exchanger 10 and is formed integrally with the heat exchanger 10, as shown by the black arrow. It exits into the shell 16 through a window 15 opened at the bottom of the shell 14. 1 flowing through the heat exchanger tube 11
It exchanges heat with the sub-system coolant and exits from the central hole 17 of the upper tube sheet 12 to the upper steam generator 20. 21
is a heat exchanger tube bundle made up of helical coil type heat exchanger tubes of the steam generator 20, and a tertiary side fluid, which is a steam system, flows through the heat exchanger tubes. The tertiary side fluid (water) sent from a water supply pump (not shown) flows in from the nozzle 22, passes through the downcomer tube 24, enters the heat exchanger tube from below the heat exchanger tube bundle 21, and flows outside the tube. It exchanges heat with the secondary coolant flowing through it, becomes steam, flows out from the nozzle 23, and is supplied to a turbine (not shown). Center hole 1 of upper tube plate 12
The secondary coolant coming out of the tube 7 rises inside the riser tube 25, exits the upper part of the heat exchanger tube bundle 21, goes down the outside of the heat exchanger tube, turns over below the heat exchanger tube bundle 21, and flows into the shroud 2.
6 and the cylinder 27 to reach an outlet nozzle 28 and a secondary system circulation pump (not shown). The secondary coolant pressurized by the same pump is
The downcomer pipe 14 flows into the downcomer pipe 30 from the nozzle 29 and descends therein, and is aligned with the downcomer pipe 30 and connected thereto via the relative displacement absorbing structure 31.
flow inside. Therefore, the heat of the primary coolant is
In a shell and tube heat exchanger, the secondary coolant is transferred to the secondary coolant flowing outside the tubes, and this secondary coolant is passed outside the tubes of a steam generator installed at the top of the heat exchanger to cool the inside of the tubes. This is transmitted to the water in the flowing tertiary fluid, and the water exits as steam. Thus, the shell-and-tube heat exchanger 10 and the steam generator 20 are integrated, and the central downcomer pipe 30 for extra-tube fluid of the steam generator 20 and the central downcomer pipe 14 for extra-tube fluid of the heat exchanger 10 are integrated. Since they are aligned and connected, the long extra-tube fluid transport piping that conventionally connected the heat exchanger and steam generator is no longer needed. In addition, the steam generator, which conventionally took up a considerable amount of space, can fit into the space above the shell-and-tube heat exchanger, which saves space and greatly reduces the size of the reactor auxiliary building. In addition, equipment costs can be reduced by eliminating piping, and the capacity of equipment for transferring extra-tubular fluid can be reduced.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a flow diagram of a heat medium in a conventional fast breeder reactor, and FIG. 2 is a schematic cross-sectional view showing one embodiment of the present invention. Shell and tube heat exchanger...10, Steam generator...20, Central downcomer for fluid outside the steam generator...30, Central downcomer for fluid outside the heat exchanger...14, Relative displacement Absorption structure...31.

Claims (1)

[Claims] 1 Shell and tube type heat exchanger at the bottom,
A steam generator is disposed in the upper part and integrally formed, and a central downcomer pipe for extra-tube fluid of the steam generator and a central downcomer pipe for extra-tube fluid of the heat exchanger are aligned and connected; A relative displacement absorbing structure is provided in the connecting portion, and a pump circulates the extra-tube fluid of the steam generator and the heat exchanger, and the water supplied in the heat transfer tubes installed in the steam generator is heated and evaporated by the extra-tube fluid. A steam generation plant characterized by being configured as follows.