JPS59164887A - Heat storage reservoir installation - Google Patents

Abstract

PURPOSE:To prevent a deterioration of thermal efficiency to improve safety of a reservoir by providing a heat insulating outer tube having an expandable joint in the internal tubing of a heat storage reservoir, and providing breathing nozzle protruding outside an outer reservoir to such a heat insulating outer tube. CONSTITUTION:An internal tubing 22a of a heat storage reservoir is formed with a heat insulating outer tube 2 which is made of steel plate in an airtight and watertight manner in an outer reservoir. The riser part of the heat insulating outer tube 2 has an expandable joint 2a to absorb expansion and contraction due to a temperature change which is formed likewise in an airtight and watertight manner. Inside of the outer tube 2 and the expandable joint 2a is filled with heat insulating material 5 and overlying resilient heat insulating material 4 for heat insulation. The heat insulating outer tube 2 has a breathing nozzle 6 protruding from an outer reservoir 8 so that changes in the internal pressure due to expansion and contraction of the heat insulating outer tube 2 may be relieved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the creation of a heat storage tank facility, which provides a highly durable heat storage tank facility that economically forms a liquid heat medium transfer pipeline that repeatedly changes temperature within the heat storage tank under favorable heat retention conditions. This is what we are trying to provide.

Conventionally known thermal storage and heat exchange systems, which recover high-temperature waste heat using a heat medium such as molten salt and reuse the thermal energy, have a high-temperature side storage tank and a low-temperature side storage tank. The side storage tank stores molten salts at 50°C, and the low temperature side storage tank stores molten salts at 250°C.
A heat exchanger is installed in the middle of the piping that connects the main storage tank to recover heat from excess steam during heat recovery, and heats the saturated steam during reuse.Each storage tank is equipped with a main valve and a discharge nozzle. A circulation pump is installed on the side. By the way, such a heat storage system uses one storage tank in addition to the two storage tanks as described above, stores a low-temperature medium in the lower part, stores a high-temperature heat medium with a light specific gravity in the upper part, and stores each tank separately. There is also a known system that uses nozzles and heat exchangers similar to those described above to switch between heat storage and heat dissipation states. There are disadvantages. The two-tank system requires two storage tanks, which means that the construction site for the plant is larger, and the foundation work, storage tank construction, heat insulation work, etc., will also be nearly twice as expensive, which is a waste of money. In terms of safety, it is recommended that the space above the liquid in each storage tank be filled with an inert gas such as nitrogen gas, but between the two storage tanks it is recommended to fill the space above the liquid at 250°C and 500°C as mentioned above. When there is a difference in temperature between the two, when the thermal energy transfers from the low-temperature part to the high-temperature part (the heat medium moves from the high-temperature side to the low-temperature side), the gas expands and the internal pressure of the storage tank increases. However, in the opposite case, the internal pressure of the storage tank decreases, so special consideration must be taken for strength of the storage tank, such as providing a pressure regulating gas holder, which also increases costs. On the other hand, the one-tank system is considered to be low cost, but the side plate surface that receives the liquid pressure can directly withstand thermal stress due to rise (expansion) and fall (shrinkage) within the temperature difference range of 250 to 500℃ as mentioned above. This material (heat-resistant steel) is not easy to obtain.

The inventors of the present invention have made repeated studies to eliminate the disadvantages of the conventional conventional ones as described above, and have created an internal storage tank in which a heat insulating material is suitably attached concentrically to the external storage tank provided with a heat insulating material. The proposed method is to form a communication hole with the external storage tank in the lower part of the side wall of the internal storage tank, and to provide piping that communicates with the internal storage tank via a heat exchanger (Japanese Patent Application No. 5'7-19978). '5).

That is, this device is as shown in FIG. 1, and is constructed on a bottom heat insulating material 12 provided on a foundation 10.A liquid-tight and airtight external storage tank 8 is covered with a heat insulating material 8a on the outside. An internal storage tank 9 is provided concentrically inside the storage tank 8, and a heat insulating roof is provided above the internal storage tank 9. Further, the internal storage tank 9 is formed of a wall with sufficient heat insulation performance to separately store heat media having different temperatures, and a through hole 9a communicating with the external storage tank 8 is formed near the bottom of the internal storage tank 9. The spacing between the walls of both storage tanks 8 and 9 is selected within an appropriate range that takes up space for construction work. Further, a nozzle 16 for introducing the low-temperature side heat medium and a dispensing nozzle 1T are provided on the bottom side surface of the external storage tank 8, and the dispensing nozzle 1γ is connected to the heat medium liquid level a.
A rising pipe 1γa is provided which opens to a predetermined depth from the bottom, and a main valve 18 is provided to each of these nozzles 16 and 17. It is connected to a heat exchanger 20. Also, a pipe 24 from the heat exchanger 20 passes through the internal storage tank 9 and is connected to a receiving nozzle 21 and a discharging nozzle 22. '221'i is introduced as one pipe 22b into the internal storage tank 9 and rises up from the liquid inside the nuclear storage tank 9 to a predetermined depth.

A main valve 23 is attached to these nozzles 21 and 22,
The nozzle 16.1 also has a circulation pump 15a.
7, a steam pipe 27 for receiving and discharging heat is passed through the heat exchanger 20, and a suction pipe 27 for filling the inner space of the storage tank 8 with a cover gas such as an inert gas is connected to the heat exchanger 20. A side safety valve 25 and a safety valve 26 for the storage tank 8 itself are provided. In other words, with this configuration, this type of equipment can be constructed relatively and economically, and it is also industrially popular as it reduces thermal fatigue caused by temperature changes and improves heat retention and durability. It can be said that it is a very meaningful facility.

However, although this new method is used, the internal piping 22a for transferring the heat medium between the inner and outer storage tanks 8 and 9 at the time of fusion is connected to the low-temperature molten salt side when the heat medium such as molten salt is transferred. There is a tendency for heat exchange through the pipe wall to deteriorate the thermal efficiency of the storage tank.However, such internal pipe 22a is submerged in the molten base as shown in FIG. Molten salt SL of 250℃ to 500℃ due to temperature change of molten salt in the range of height h
It is affected by the molten salt SH, or by repeated temperature changes from 500°C to 250t, making it extremely difficult to insulate such internal piping.

The present invention was devised after repeated studies in view of the above-mentioned circumstances, and a specific embodiment thereof is as shown in FIG. That is, the heat-insulating outer cylinder 2 made of a steel plate or the like formed airtight and liquid-tight with respect to the internal piping 22a is connected to at least the external storage tank 8.
In addition, an expansion joint 2a that absorbs expansion and contraction due to temperature changes is similarly formed in a liquid-tight and airtight state at the rising edge of the heat-insulating outer cylinder 2, and the inside of the heat-insulating outer cylinder 2 and the expansion joint 2a are formed in a liquid-tight and air-tight manner. A heat insulating material 5 made of a molded body such as calcium silicate and a relatively flexible heat insulating material 4 such as rock wool are filled in a laminated state to prevent temperature changes from the time of construction of the pipe 22a to its use. The expansion and contraction of the insulation outer cylinder 2 is accordingly absorbed, and the breathing nozzle 6 is installed by appropriately protruding the insulation outer cylinder 2 from the external storage tank 8 to prevent fluctuations in the internal pressure due to the expansion and contraction of the insulation outer cylinder 2. , so that the pressure is always constant.

The heat retaining outer cylinder 2 is firmly attached to at least the side plate of the external storage tank 8 by welding, and a support member 7 is appropriately provided in the internal storage tank 9 and inserted into the through hole 9a of the internal storage tank 9. It is designed to be supported in a stable state in a stable state. That is, according to the present invention, the internal piping 22a is properly insulated and can effectively respond to expansion and contraction. The thermal efficiency of the storage tank can be effectively avoided and deterioration of the thermal efficiency of the storage tank can be prevented.Moreover, the heat insulating material of such a heat insulating tank is made of a heat insulating outer cylinder 2 made of a steel plate, etc., and is suitable for preventing permeation of molten salt. They can be used for industrial purposes because they can fully demonstrate the characteristics of an economical and highly safe thermal storage tank with little thermal fatigue. This is a highly effective invention.

[Brief explanation of drawings]

The drawings show the technical contents of the present invention, and Fig. 1 is an explanatory diagram showing a cross-sectional view of the structural relationship of the prior proposal by the present inventors, and Fig. 2 is an explanatory diagram showing the internal piping in the molten salt. FIG. 3, which is an explanatory diagram of the set state, is a sectional view partially showing the heat-retaining and heat-insulating structure of the internal piping according to the present invention. In these drawings, reference numeral 2 indicates a heat insulating outer cylinder 2a, its expansion joint, 4 a heat insulating material such as rock wool, 5 a molded body heat insulating material, 6 a breathing nozzle, 7 a support member, 8 an external storage tank, and 9. is the internal storage tank, 10 is the foundation, 12 is the bottom insulation material, 1
4 is a pressure equalizing pipe, 14a is its rising part, 15° 15 & is a pump, 16 is an introduction nozzle, 17 is a discharge nozzle, 18
is the main valve, 19 and 19a are the pipes, 21 is the receiving nozzle, 2
2 is a discharge nozzle, and 22a is an internal pipe. Patent applicant Nippon Kokan Co., Ltd. Inventor Takeshi Toriyabe Agent Patent attorney Shirakawa -- 4 children / m 2nd ■

Claims (1)

[Claims] An internal storage tank provided with a heat insulating material is set at a distance from an external storage tank provided with a heat insulating material, and a communication hole with the external storage tank is formed in the lower part of the side wall of the internal storage tank, and An internal piping is provided that connects the external storage tank to the internal storage tank via a heat exchanger, a heat insulating outer cylinder having an expansion joint is provided in the internal pipe, and a heat insulating material is filled between the heat insulating outer cylinder and the internal pipe. The heat storage tank equipment is further characterized in that the heat insulating outer cylinder is provided with a breathing nozzle that protrudes outside the external storage tank.