JP2002147978A - Cold thermal energy storage tank and method for constructing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently construct a cold thermal energy storage tank used for an LNG cold energy system. SOLUTION: A heat storage unit 11 is produced by filling a curing heat storage material around piping which has been assembled in advance. One or a plurality of the units are embedded in a number of grooves 3 that have been dug in a dimension suitable for the units, and connected to each other to constitute an aggregate 10 of the heat storage material. The ends of the piping, which are located on the upper surface the aggregate 10, are connected to each other to form a pipeline which is integrated into the aggregate 10. Cold energy liquefied gas is permitted to flow in the pipeline to provide cold energy piping. Further, heat insulating layers 12, 13 are constructed so as to surround the bottom of the base and the outer periphery of the aggregate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold heat storage tank and a method of constructing the same, and more particularly, to an LNG cold heat utilization system, which liquefies LNG cold heat and liquefies other useful gases such as air by the stored cold heat. The present invention relates to a cold heat storage tank that stores and stores a cold heat storage tank, and a method of constructing a cold heat storage tank that can quickly and economically construct the cold heat storage tank.

[0002]

2. Description of the Related Art As means for effectively utilizing LNG energy,
An LNG cold energy utilization system is being planned. The LNG cold energy utilization system has not been actively used in the past.
G Large-scale cold heat storage tank and liquefied gas storage tank capable of storing heat up to ultra-low temperatures are provided in the system for the purpose of using cold energy with high efficiency. Used to liquefy and store other useful gases. Since the LNG cold energy utilization system is operated in the daytime operation mode and the nighttime operation mode, it experiences a heat cycle from room temperature to extremely low temperature in a one-day cycle. For this reason, a large temperature difference occurs inside, and therefore, when constructing a large heat storage tank, it is necessary to establish various techniques such as a heat storage tank construction technique and a heat shield.

[0003] In the LNG cold heat utilization system, a large-sized cold heat storage tank and a liquefied gas storage tank are constructed to store cold heat obtained during heat exchange for vaporizing LNG. It is assumed that the cold heat storage tank has a plane scale of 30 to 50 m square and a capacity of about 20 m depth. The cold heat storage tank is mainly composed of a heat storage material aggregate in which a plurality of heat storage material units each having a predetermined shape are assembled, and the total weight as a whole is assumed to be 50,000 to 100,000 tons. The liquefied gas storage tank is installed adjacent to or in the cold heat storage tank to store liquefied gas in the pipe of the cold heat storage tank, and the construction method is the same as that of the LNG storage tank.

At present, the heat storage material unit has a structure in which a heat storage material mainly composed of a cast-in-place material such as concrete, mortar, and self-hardening bentonite is filled around a cooling / heating pipe provided in the unit. The scale is designed to have a plane dimension of 2 m on a side and a height of about 20 m, and to cover the outer surface with a heat insulating material or the like as necessary.

[0005] As a conventional method of constructing a cold heat storage tank, a continuous wall underground is formed so as to form a box-like or cylindrical retaining space in the ground, and a scaffold or a scaffold is formed in the retaining space obtained by excavating the inside. Arrange the support, perform the cold pipe for the heat storage tank, further surround the cold pipe with a mold, fill the inside with the heat storage material, and sequentially remove the mold after the heat storage material is cured. There is a way to repeat.

[0006]

However, the conventional method for constructing a cold heat storage tank requires an area occupied by a temporary structure such as an underground continuous wall around a site required as a heat storage tank. In addition, because this underground continuous wall has the required strength and rigidity as a retaining wall and a structural frame, a large-scale one is necessary, and on the construction side, in concrete construction to construct a heat storage tank in the retaining space, Mass scaffolding, shoring,
There was a problem in that temporary materials such as formwork were required, and the overall construction cost was high.

[0007] Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to manufacture a precast concrete member as a heat storage material unit in advance, and to build this heat storage material unit into a buried groove, or A cooling heat storage tank and a method for constructing the same that can perform quick and economical construction by constructing a heat storage material unit by embedding a piping unit in a buried groove and directly filling a hardened material such as concrete into the groove. To provide.

[0008]

In order to achieve the above object, the present invention provides a heat storage material unit manufactured by filling a pre-assembled pipe with a curable heat storage material and a heat storage material unit formed on a predetermined plane. A heat storage material assembly in which the heat storage material units buried are connected to each other in a large number of grooves excavated to a size that can accommodate one unit or a plurality of units over a range, and an upper surface of the heat storage material assembly. It is constructed so as to surround the bottom and outer periphery of the heat storage material aggregate in the ground, and a cold heat pipe in which the pipe ends of the located pipes are connected to each other to form an integrated conduit in the heat storage material aggregate. And a heat insulating layer.

[0009] As a method of constructing a cold heat storage tank, a heat storage material unit manufactured by filling a pre-assembled pipe with a curable heat storage material is inserted into a groove excavated to a size that can accommodate one or more units. A plurality of heat storage material units embedded in a predetermined plane area of the ground are connected to each other to form a heat storage material aggregate having a heat insulating layer on the bottom and the outer periphery thereof, and the upper surface of the heat storage material aggregate Are connected to each other to form a cooling / heating pipeline integrally with the heat storage material assembly.

[0010] Another construction method is as follows:
A pre-assembled piping unit is sunk in the groove, and a non-solidified curable heat storage material is filled in the groove around the piping unit and solidified to form a heat storage material unit. The heat storage material assembly provided is formed, and the pipe ends of the piping units located on the upper surface of the heat storage material assembly are connected to each other to form a cold heat pipe integrally with the heat storage material assembly. It is characterized by.

In these construction methods, the heat insulating layer at the bottom of the heat storage material assembly may be provided in advance at the bottom of the heat storage material unit or may be provided in the groove prior to embedding the heat storage material unit. The heat insulating layer on the outer periphery of the heat storage material aggregate is provided after the heat storage material aggregate is formed, or is provided in advance on the outer circumference of a heat storage material unit embedded in the outer periphery.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cold heat storage tank (hereinafter simply referred to as a heat storage tank) of the present invention and a method for constructing the same will be described below with reference to the accompanying drawings.

[Heat storage material unit using precast concrete members] FIG. 1A is a plan view of a heat storage tank 1 for use in the LNG cold energy utilization system of the present invention, and FIG.
(B) is the same sectional view. This heat storage tank 1 is an underground structure type heat storage tank constructed by a method described later, and has a side of about 2
It has a rectangular planar shape of 0 m and dimensions of 20 m depth. In the present embodiment, a heat storage material aggregate 10 is formed by aligning and assembling a plurality of heat storage material units 11 in a plane, and the outer periphery thereof is surrounded by a heat insulating wall 12, as shown in FIG. A heat insulating layer 13 is also formed on the bottom of the heat storage material assembly 10. In addition, a heat insulating layer (not shown) is provided on the upper surface, and the whole is covered with a building (not shown). In the present embodiment, one heat storage material unit 11 is approximately 1 m × 1 m × 20.
m. In FIGS. 1 and 2,
For the sake of simplicity, the plane dimensions of the heat storage material unit 11 are shown large, so that the number of the heat storage material units 11 constituting the heat storage material assembly 10 is smaller than the number determined from the size. In addition, other equipment configurations used for the cold heat pipe 20 (see FIG. 3) in the heat storage material unit 11, the ground building, and the cold heat utilization system are not shown.

Hereinafter, the configuration of the heat storage material unit 11 of the present invention and a method of manufacturing the same will be briefly described. Thermal storage tank 1
Is preliminarily manufactured on the ground as a precast concrete member. A cooling pipe 20 (see FIG. 3) and a reinforcing steel cage are arranged inside a formwork placed horizontally in a production yard on the ground, with a predetermined covering secured by a support frame or the like. Then, a precast concrete member is manufactured by placing (filling) concrete as a curable heat storage material in the mold. The heat storage material unit 11 on which the concrete is cast is cured for a predetermined period until a predetermined compressive strength of the concrete is developed, and then is removed from the mold, carried into a construction yard, and temporarily placed.

As shown in FIG. 3, the cooling / heating pipes 20 provided in the heat storage material unit 11 extend in the longitudinal direction so as to secure a sufficient extension within the capacity of the heat storage material unit 11 having a vertically long and small cross section. It consists of a stainless steel pipe that has been bent several times. The pipe end 22 is piped so as to be located at the upper end face when the heat storage material unit 11 is suspended in the groove. In addition, a large number of stainless steel radiating fins 22 are formed on the outer periphery of the pipe to promote heat transfer with the surrounding concrete. In addition, due to the configuration of the cold heat utilization system, a cold heat pipe 20 of a predetermined path is provided in the heat storage tank 1 for storing heat during heat exchange of the cold liquefied gas. As a filler used for filling the heat storage material unit 11, concrete is usually used. However, in order to enhance the heat storage efficiency, an aggregate containing a substance having a high thermal conductivity such as a non-corrosive metal mineral is used. It is also preferable to use a concrete made of

Further, mortar, self-hardening bentonite and the like may be used. In place of the reinforcing bar cage, the reinforcing bars can be arranged on the steel frame supporting the cooling / heating pipe, and can be used as a reinforcing guide.

Hereinafter, the construction work of the heat storage tank 1 in the construction yard will be described in order with reference to FIGS. A buried groove 3 in which the heat storage material unit 11 can be buried as it is is excavated at a position where the heat storage material assembly 10 is to be constructed. As shown in FIG. 2A, a plurality of the buried trenches 3 are excavated in the vertical and horizontal directions over the range of the plane of the heat storage tank 1. For excavation of the buried groove 3, a known excavator 2 that excavates a wall groove when a conventional underground continuous wall is formed can be used. FIG. 2 (a),
As shown in FIG. 2 (b), it is preferable to use an excavator 2 having an excavation head having an excavation cross section capable of completing excavation of a buried groove 3 of 1 m square in one gut, for example.
In the present embodiment, the case of one gut and one unit is shown. However, the above-described excavator can also perform the construction of nine units of one gut (3 × 3), and the excavator can also construct ten units of one gut (1 × 3).
× 10) trench excavation is also possible.

When excavating this buried trench, as shown in FIGS. 2 (c) and 2 (d), the preceding buried trench 3 is staggered so that the inside of the trench is always filled with the stable liquid 4. In addition, the excavation accuracy of each buried groove 3 and the stability of the groove wall can be improved. When the excavation of the buried trench 3 is completed, a bottom heat insulating layer 13 having a predetermined thickness is formed at the bottom of the trench. When constructing the bottom heat insulating layer 13, it is preferable to provide several pits (not shown) at the bottom of the groove on the outer peripheral portion, through which water can pass through the crushed stone layer. As a result, it is possible to prevent the heat storage tank from being partially or entirely raised or settled due to the freezing and thawing action of the ground. Note that a known heat-insulating material that has been subjected to waterproof processing can be provided in the bottom heat-insulating layer 13. Further, a heat insulating material can be integrally attached to the lower end of the heat storage material unit 11.

Subsequently, as shown in FIG. 2D, the heat storage material units 11 are sequentially built in the preceding buried groove 3, and the heat storage material unit 11 already built in the preceding buried groove 3 is used as a guide. The trailing buried trench 3 is excavated. At this time, even if the surface of the heat storage material unit 11 is slightly cut,
Covering is secured to the extent that piping and reinforcement are not exposed.
By repeating this procedure, the heat storage material units 11 are buried and the adjacent heat storage material units 11 are connected to each other. Further, the buried groove 3 is excavated at a position adjacent to the groove row where the building and connection have been completed, and the heat storage material units 11 are connected to each other while the heat storage material units 11 are similarly sequentially built. By sequentially performing the excavation work, the installation of the heat storage material unit 11, and the connection work, FIG.
As shown in (f), the operation of forming the heat storage material assembly 10 can be completed only from the ground. When the heat storage material unit 11 is submerged in the burying groove 3, it is preferable to collect the stable liquid in accordance with the progress of the submerging operation.

As shown in FIG. 1, when the heat storage material unit 11 is erected on the entire plane of the heat storage tank 1 and the heat storage material assembly 10 is formed, the outer heat insulating wall is formed around the heat storage material assembly 10 by the same embedding procedure. 12 is installed. The outer peripheral heat insulating wall 12 is a precast concrete wall material previously manufactured in the above-mentioned manufacturing yard on the ground, and each wall member can constitute a wall united in the longitudinal direction by a known locking member formed at an end. It has become. Further, the heat insulating wall 12 may be a single piece of heat insulating concrete, or may have a laminated plate structure in which a rigid urethane foam plate and a concrete plate having a predetermined thickness are integrally surface-bonded. Further, by forming a heater tube (not shown) as an integral heat insulating material, the groove width can be reduced.

FIG. 3 is a partial cross-sectional view schematically showing a pipe state in the heat storage material unit 11. In the figure, the stabilizing liquid 4 is inserted into the buried groove 3 excavated between the adjacent heat storage material units 11.
Is satisfied, and the heat storage material unit 11 is suspended in the buried groove 3 by the hoisting machine 5 on the ground.
The stabilizer 4 is supplied from a ground plant 6 via a stabilizer supply pipe 7. As shown in the figure, the pipe ends 21 of the pipes 20 in the unit are respectively connected to the heat storage material units 11.
By connecting the adjacent pipe ends 21 located on the upper surface with connecting pipes (not shown) on the ground, an integrated pipe line can be formed in the heat storage material assembly 10.

FIG. 4 is a schematic explanatory view showing the structure of the connecting means between the heat storage material units 11 described above. The heat storage material assembly 10 is configured in a state where vertically long heat storage material units 11 are adjacently assembled as shown in FIG. By providing the connection guides 30 (30A and 30B in the figure) between the adjacent heat storage material units 11, the arrangement, alignment and connection work of each heat storage material unit 11 can be facilitated. By connecting the heat storage material units 11 to each other, the deformation resistance of the heat storage material assembly 10 can be increased, the relative displacement between the units 11 generated during an earthquake or the like is suppressed to a predetermined amount or less, and It is possible to prevent damage at the connection point. The figure shows the heat storage material unit 1
A state is shown in which a PC steel rod 32 is inserted into a sheath 31 arranged at a predetermined position of one head, and is horizontally tightened between adjacent heat storage material units 11. Thereby, the connection at the head of the heat storage material unit 11 is ensured. At the lower end of the heat storage material unit 11 is a connection guide 3 made of a processed steel shape.
0A and 30B are attached. Heat storage unit 1
The connection guide 30B of the succeeding heat storage material unit 11 is engaged with a part of the connection guide 30A attached to one end of the preceding heat storage material unit 11 when the first heat storage material unit 11 is installed. Thereby, the lower end of the vertically long heat storage material unit 11 can be easily connected. Also, a hole-in anchor (not shown) or the like is cast on the head of the heat storage material unit 11 and a stiffening material such as an H-shaped steel or an angle iron is laid between the heat storage material units 11 to thereby form the heat storage material unit 11. May be connected.

FIG. 5 is a partial sectional plan view showing an example of a state in which the heat storage material unit 11 is erected using the connection guides 30A and 30B. As shown in the figure, a connection guide 30A made of angle steel is provided on both side surfaces of the heat storage material unit 11, and a connection guide 30B made of H-shaped steel for locking a flange in a recess of the connection guide 30A. Is provided. When the heat storage material unit 11 is buried in the groove, by locking them, the heat storage material unit 11 can be accurately placed in the groove.

On the other hand, there is a case where it is not necessary to strengthen the connection between the heat storage material units 11. In such a case,
After the heat storage material unit 11 is installed in the preceding buried groove 3, the surroundings of the groove are filled with a hardening material such as concrete or mortar, or the inside of the buried groove 3 is filled with self-hardening bentonite with the groove stabilizing liquid 4, and then built. Heat storage material unit 11 inserted
It is also preferable that the heat storage material unit 11 be integrated by hardening the heat storage material unit 11 in the buried groove 3. In this case, the heat storage material unit 11 is also fixed in the subsequent buried groove 3, but when excavating the subsequent buried groove 3, the wall surface of the hardened material such as concrete or mortar around the preceding heat storage material unit 11 is removed. It is preferable to remove the stable liquid slime between the preceding unit and the following unit by excavating while slightly cutting.
Thereby, integration between adjacent heat storage material units 11 can be ensured.

[Heat storage material unit using cast-in-place solidified material]
FIG. 6 is a construction sequence explanatory view showing a construction procedure of the heat storage material unit in which the heat storage material unit 11 is constructed on site by using a cast-in-place solidified material. In this construction method, FIG.
Excavating the rectangular parallelepiped buried groove 3 excavated by the excavator 2 in the same manner as shown in (a) to FIG. 2 (c) (FIG. 6 (a)).
-FIG. 6 (c)). Then, the piping unit 20 is buried in the buried groove 3 filled with the stabilizing liquid. This piping unit 20
Is the flow path inlet and flow path outlet at the upper end of the pipe (both not shown)
The piping is configured such that the lower end of the piping extends to near the lower end of the buried groove 3 and is configured to make a U-turn, and adjacent piping units are connected to each other on the ground portion to form a cooling / heating pipe. Further, in the buried groove 3 in which the piping unit 20 is sunk, FIG.
As shown in (d), the cast-in-place solidified material as the unsolidified heat storage material supplied from the solidified material plant 8 installed on the ground is tremy-cast. As the unsolidified heat storage material, known mortar, self-hardening bentonite, and the like are preferable. These are a cast-in-place solidification material, after a predetermined lapse of time in the buried groove 3, and a pipe unit 20 as a heat storage material integrated therein. To solidify. Thereby, the heat storage material unit 11 is constructed. This process is shown in FIGS.
As shown in (f), the process is repeatedly performed over a predetermined heat storage tank construction range, a heat storage material assembly is constructed, and finally, the above-ground portions of the respective piping units are connected to each other to form a cooling / heating pipeline, and further, the above-ground connection portion is formed. Is covered with heat insulating material to complete the cold heat storage tank.

[0026]

As described above, according to the present invention, the main body of the cold heat storage tank can be constructed without forming a temporary underground continuous wall, the flat area of the structure is reduced, and the heat storage material unit is reduced. Since the cooling and heating pipes are incorporated in the inside, the effects such as the drastic reduction of the piping work and the rationalization of the construction can be achieved.

[Brief description of the drawings]

FIG. 1 is a plan view and a sectional view showing an embodiment of a heat storage tank according to the present invention.

FIG. 2 is an explanatory view of a construction sequence schematically showing a procedure of a construction operation of the heat storage tank shown in FIG.

FIG. 3 is an explanatory diagram showing a schematic configuration of a cooling / heating pipe provided in a heat storage material unit in a unit cross section.

FIG. 4 is an explanatory diagram showing a cross section of an embodiment of connection of a heat storage material unit.

FIG. 5 is a partially enlarged cross-sectional view showing one embodiment of a positioning accuracy improving means for a lower end of a heat storage material unit.

FIG. 6 is a construction sequence explanatory view schematically showing a procedure for constructing a heat storage tank by a heat storage material unit using a cast-in-place solidifying material.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cold heat storage tank (heat storage tank) 2 excavator 3 buried groove 4 stable liquid 10 heat storage material assembly 11 heat storage material unit 12 outer heat insulation wall 13 bottom heat insulation layer 20 cold heat pipe (pipe unit) 21 pipe end 30 connection guide 32 PC steel rod

Continuation of front page (72) Inventor Yoji Nishikawa 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation F-term (reference) 3E070 AA02 AA13 AB32 DA05 EA04 NA01

Claims (4)

[Claims] 1. A heat storage material unit manufactured by filling a curable heat storage material around a pipe that has been assembled in advance, and excavating the heat storage material unit to a size that can accommodate one or more units over a predetermined plane range. A heat storage material assembly in which the heat storage material units embedded in the plurality of grooves are connected to each other, and pipe ends of the pipes located on the upper surface of the heat storage material assembly are connected to each other to store heat. The heat storage material assembly includes a cooling pipe configured to form an integrated conduit and allowing a cooling liquefied gas to flow therein, and a heat insulating layer constructed to surround a bottom and an outer periphery of the heat storage material assembly in the ground. A cold heat storage tank. 2. A heat storage material unit manufactured by filling a curable heat storage material around a pipe assembled in advance and burying the heat storage material unit in a trench excavated to a size capable of accommodating one or a plurality of units. A plurality of heat storage material units buried over a predetermined plane range are connected to each other to form a heat storage material aggregate provided with a heat insulating layer portion on the bottom and outer periphery, and the heat storage material aggregate is provided on the upper surface of the heat storage material aggregate. A method for constructing a cold heat storage tank, characterized in that pipe ends are connected to each other to form a cold heat pipe integrally in a heat storage material assembly. 3. A pre-assembled piping unit is set in the excavated groove, and an unsolidified curable heat storage material is filled in the groove around the piping unit and solidified to fill the groove. While building a heat storage material unit, to form a heat storage material aggregate provided with a heat insulating layer on the bottom and outer periphery,
A method for constructing a cold heat storage tank, wherein the pipe ends of the piping units located on the upper surface of the heat storage material assembly are connected to each other to form a cold heat pipe integrally with the heat storage material assembly. 4. The heat storage material assembly according to claim 1, wherein the heat storage material assembly has a heat insulating layer at the bottom of the heat storage material unit, or is provided in the groove before the heat storage material unit is buried. The heat insulating layer portion on the outer periphery of the body is provided after the heat storage material aggregate is formed, or is provided in advance on the outer periphery of the heat storage material unit embedded in the outer periphery. 3. The method for constructing a cold heat storage tank according to 3.