JP2015190113A - Heat storage tank allowing pinhole inspection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel heat storage tank allowing pinhole inspection.SOLUTION: The heat storage tank allowing pinhole inspection comprises a concrete skeleton, a heat insulation layer that is formed on the internal surface of the concrete skeleton and is composed of on-site foaming urethane heat insulation materials or heat insulation molding plates, a conductive layer formed on the internal surface of the heat insulation layer, and a water resistant layer formed on the internal surface of the conductive layer and composed of polyurea resin. The conductive layer comprises a primer with conductive materials mixed therein.

Description

  The present invention relates to a heat storage tank capable of pinhole inspection.

  An example where a waterproof function is required is a heat storage tank. Recently, from the viewpoint of effective use of energy, an example of introducing a heat storage system into an air conditioning facility of a building is increasing. For example, FIG. 1A is an example of a water regenerative air conditioning system that uses an empty space (double slab) 2 of a building 1 as a cold / hot water tank. As shown to FIG. 1B, a cold / hot water tank is formed using the space 2 between the floor slab 5 and the foundation slab 6 of the lowest floor.

  In a water thermal storage air conditioning system, cheap electricity (midnight power) at night is used to store heat energy in a cold / hot water tank. Specifically, the heat source device 3 is operated with electric power at night and used as a cold water tank in which cold water is stored in summer. Cooling is performed using cold water stored in the cold water tank during daytime cooling. On the other hand, in winter, it is used as a hot water tank that stores hot water, and during the daytime heating, it is heated using the hot water stored in the hot water tank.

  When the heat storage system is not employed, the heat source unit 3 is operated in accordance with the air conditioning load in the daytime (air conditioning time zone). On the other hand, when a heat storage system is employed, heat energy is stored by heat storage operation at night (time zone other than the air conditioning time zone), and this energy is used for daytime air conditioning (heat radiation). The chasing operation is performed by the heat source device 3 on the day when the air conditioning load is large. The heat storage system can reduce the necessary installation capacity, and is excellent in economic efficiency.

  The concrete casings 5, 6, and 7 forming the heat storage tank 4 have poor water-stopping properties and large heat loss. For this reason, as shown in FIG. 1B, the heat storage tank 4 reduces heat energy loss and prevents condensation on the outer surfaces of the concrete frames 5, 6 and 7, thus preventing heat insulating material 8 and water leakage on the inner surface of the concrete frame. It is formed using the waterproof material 9.

  In addition to the cold / hot water tank that switches between cold water and hot water depending on the season, the heat storage tank 4 may be, for example, an ice heat storage tank that always stores ice or cold water of about 4 ° C. depending on the application. There are dedicated tanks for cold water to be stored and dedicated tanks for hot water that always store hot water of about 50 ° C.

Japanese Patent Application Laid-Open No. 2010-31600 “Waterproof coating structure for pinhole inspection” (release date: February 12, 2010) Applicant: TEPCO

  The waterproof material 9 used here should not have a fragile portion or a pinhole (small hole) with an extremely thin film thickness so as not to leak the water stored inside the heat storage tank to the outside. Therefore, after the heat storage tank 4 is completed, it is necessary to provide means (hereinafter simply referred to as “pinhole inspection”) for inspecting that the waterproof material 9 has no extremely thin portions or pinholes. It becomes. By presenting the result of the pinhole inspection to the customer, the quality assurance regarding the waterproof material 9 of the heat storage tank 4 can be performed. For this reason, realization of the heat storage tank which can perform a pinhole test | inspection reliably after formation of a heat storage tank is desired.

  Accordingly, an object of the present invention is to provide a novel heat storage tank capable of pinhole inspection.

  A heat storage tank capable of inspecting a pinhole according to the present invention includes a concrete housing, a heat insulating layer formed of an in-situ foamed urethane heat insulating material formed on the inner surface of the concrete housing, and a conductive material formed on the inner surface of the heat insulating layer. And a waterproof layer made of polyurea resin formed on the inner surface of the conductive layer.

  Alternatively, the heat storage tank capable of inspecting a pinhole according to the present invention includes a concrete casing, a heat insulating layer formed of a heat insulating molded plate formed on the inner surface of the concrete casing, and a conductive layer formed on the inner surface of the heat insulating layer. And a waterproof layer made of polyurea resin formed on the inner surface of the conductive layer.

  Furthermore, in the heat storage tank in which the pinhole inspection is possible, the conductive layer may be made of a primer mixed with a conductive substance.

  Furthermore, in the heat storage tank in which the pinhole inspection is possible, the conductive substance mixed in the conductive layer may be made of powdered, particulate or fibrous metal or carbon.

  Furthermore, in the heat storage tank in which the pinhole inspection is possible, the conductive layer may be a urethane primer mixed with at least 5% by weight of carbon black.

  Furthermore, in the heat storage tank capable of performing the pinhole inspection, the voltage applied to the conductive layer during the pinhole inspection may be 5 to 11 kV.

  ADVANTAGE OF THE INVENTION According to this invention, the thermal storage tank in which a novel pinhole test | inspection is possible can be provided.

FIG. 1A is a diagram illustrating an example of a water heat storage type air conditioning system that uses an empty space formed by a double slab of a building as a heat storage tank. FIG. 1B is a detailed view of a water heat storage tank formed using the space between the floor slab and the foundation slab on the lowest floor. FIG. 2A is a diagram illustrating the structure of an ice heat storage tank and a chilled water dedicated tank. FIG. 2B is a diagram illustrating the structure of the hot water dedicated tank and the cold / hot water tank. FIG. 3 is a diagram for explaining a pinhole inspection method. FIG. 4 is a diagram for explaining a thermostock method as a heat storage tank method capable of performing another pinhole inspection.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a waterproof coating layer structure capable of pinhole inspection according to the present invention, a heat storage tank incorporating the same, a rooftop roof, and the like will be described in detail with reference to the accompanying drawings. In the figure, the same elements are denoted by the same reference numerals, and redundant description is omitted.

One of the applicants in the above-mentioned patent document 1 provides a conductive primer layer on the base of the waterproof material layer and sweeps the surface of the waterproof material layer with a pinhole inspection jig to inspect for the presence of a pinhole. Proposed method. Also in this embodiment, the inspection method itself is basically the same.
Here, a novel heat storage tank having a structure different from that of Patent Document 1 and capable of inspecting a pinhole is proposed.

  In the heat storage tank 4, the cold / hot water tank is used as a hot water tank or a cold water tank in a circulating manner according to the season throughout the year. Therefore, the heat storage tank 4 is basically classified into an ice heat storage tank, a cold water dedicated tank, a hot water dedicated tank, and a cold / hot water tank.

  Currently, the waterproof layer construction range is based on the `` Guideline for Thermal Storage Thermal Insulation and Waterproofing Construction (draft) '' by the Thermal Storage Thermal Insulation and Waterproof Committee of the Architectural Institute of Japan. It is stipulated that it is not. That is, in principle, the waterproof layer is applied to the entire surface of the wall / floor, and the ceiling surface is determined by the relationship with the water temperature used. This is because water vapor has a property of moving from a higher temperature to a lower temperature.

(1) Ice heat storage tank and chilled water dedicated tank FIG. 2A is a diagram illustrating the structure of the ice heat storage tank 22 and the chilled water dedicated tank 20. The ceiling surface has a structure in which a heat insulating molded plate 16 is fixed to the inner peripheral surface side of the concrete slab 5. There is no waterproof layer.
In the ice heat storage tank 22 and the chilled water dedicated tank 20, the inside of the tank is relatively cold compared to the outside of the tank, and the water vapor moves from the outside of the tank to the inside of the tank as indicated by an arrow Sd. If there is a waterproof layer inside the tank of the heat insulating molded plate 16, the water vapor that has penetrated into the heat insulating molded plate 16 from the outside of the tank is internally condensed inside the heat insulating molded plate 16 or at the boundary between the heat insulating molded plate 16 and the waterproof layer, As a result, the condensed water stays in the waterproof layer, and on the contrary, it causes a problem in the heat insulating layer and the waterproof layer.

  The heat insulating molded plate 16 is preferably formed of a molded plate made of foamed urethane, polystyrene or the like having a thickness of about 25 to 100 mm. The reason for adopting the heat-insulated molded plate 16 only on the ceiling surface is that when a foamed urethane material used on the wall surface and floor surface is used for the ceiling surface, a skin layer is formed on the surface when sprayed and cured. This is because this skin layer has the same waterproof function as the waterproof layer. Therefore, the heat insulation molding board 16 is employ | adopted instead of the in-situ foaming urethane heat insulation layer.

  The wall surface and the floor surface are a heat insulating layer 18 disposed on the inner peripheral surface side of the concrete casing 7, a pinhole inspection conductive layer 17s formed on the inner peripheral surface side of the heat insulating layer, and an inner periphery of the conductive layer. It consists of a waterproof layer 14s formed on the surface. Furthermore, a top coat layer (not shown) may be formed on the waterproof layer 14s. The top coat layer is made of a fluororesin, an acrylic urethane resin or the like, and is used for further suppressing the moisture permeability coefficient.

  The heat insulating layer 18 is preferably formed from an in-situ foamed urethane heat insulating material having a thickness of about 20 to 100 mm and a target value of about 50 mm.

The conductive layer 17 is a primer containing a powdery, particulate or fibrous conductive material. The conductive layer 17 is about 0.1 to 0.3 kg / ^{m 2,} it is formed by coating or spraying to the target value of about 0.15 kg / ^{m 2.} The conductive material is typically a metal or carbon. The primer originally means a base coating or an adhesive used for increasing the adhesion of the paint to the base. Here, it is an adhesive that adheres the underlying heat insulating layer 18 and the upper waterproof layer 14s. In this trial production, a conductive primer in which carbon black (fine particles of carbon having a diameter of about 3 to 500 nm) is mixed with a two-component solvent type urethane primer (part number P-2080) available from Mitsui Chemicals, Inc. in the market. Evaluated.

  The waterproof layer 14s is preferably a polyurea resin waterproof layer having a thickness of about 1 to 5 mm and a target value of about 2 mm.

(2) Hot Water Dedicated Tank and Cold / Hot Water Tank FIG. 2B is a diagram illustrating the structure of the hot water dedicated tank 24 and the cold / hot water tank 26.
On the ceiling surface, a heat insulating molded plate 16 is disposed on the inner peripheral surface side of the concrete slab 5, and further, a conductive layer 17u for pinhole inspection formed on the inner peripheral surface side of the heat insulating layer, and an inner peripheral surface of the conductive layer. The waterproof layer 14s is formed. Furthermore, a top coat layer (not shown) may be formed on the waterproof layer 14s.

  First, in the dedicated hot water tank 24, the inside of the tank is relatively hot compared to the outside of the tank, and the water vapor moves from the inside of the tank to the outside of the tank as indicated by the arrow Sd2. For this reason, it is necessary to prevent the heat insulation performance of the heat insulating molded plate 16 material from deteriorating due to moisture absorption and the intrusion of water vapor to the upper floor, and the waterproof layer 14u is provided instead of the moisture barrier layer on the ceiling surface in the tank.

  Next, the cold / hot water tank 26 is used as a cold water tank or a hot water tank depending on the season. When used as a cold water tank, the direction of movement of water vapor is the direction indicated by arrow Sd1, and when used as a hot water tank, the direction is indicated by arrow Sd2. For this reason, since the dew condensation water generated during the cold water operation is volatilized during the hot water operation, the waterproof layer 14u is required as in the case of the hot water dedicated tank.

  The wall surface and the floor surface are composed of a heat insulating layer 18 disposed on the inner peripheral surface side of the wall concrete casing 7, a pinhole inspection conductive layer 17 s formed on the inner peripheral surface side of the heat insulating layer, It consists of a waterproof layer 14s formed on the peripheral surface. Furthermore, a top coat layer (not shown) may be formed on the waterproof layer 14s.

(Pinhole inspection)
The pinhole inspection itself is the same as the pinhole inspection method disclosed in Patent Document 1 described above. FIG. 3 is a diagram for explaining a pinhole inspection method. A lead wire is drawn out from the conductive layer 17 in close contact with the back surface of the waterproof layer 14, which is an insulating material, and connected to one terminal of the voltage source V. The voltage source V only needs to output a voltage of 5 kV or more, as will be described later.

  A pinhole inspection jig 30 is connected to the lead wire connected to the other terminal of the voltage source V. The pinhole inspection jig 30 is composed of a bundle of thin metal wires (metal brush-like jigs, bowl-like jigs, brush-like jigs, etc.) whose tips are flexible and flexible. It is a conductive jig that can be contacted so as to rub the surface. An ammeter I is connected in the middle of the lead wire. There may be a protection device against overcurrent.

  A predetermined voltage is applied by the voltage source V. In this state, the surface of the waterproof layer 17 is swept by the pinhole inspection jig 30. At this time, if the waterproof layer 17 has a pinhole, the inspection jig 30 and the conductive layer 17 come into contact with each other through the pinhole to form a closed circuit, and a relatively large current flows and is detected by the ammeter I. The Further, if the waterproof layer 17 has an extremely thin portion, a dielectric breakdown occurs due to the relationship with the applied voltage, and a closed circuit is formed, which is similarly detected by the ammeter I. When no current flows through the ammeter I even if the entire surface of the waterproof layer 17 is swept by the pinhole inspection jig 30, the waterproof layer 17 may not have a fragile portion or pinhole having an extremely thin film thickness. Proven.

In order to obtain detailed conditions for the pinhole inspection, the following confirmation experiment was conducted in advance on the conductive primer.
(1) Preliminary test The preliminary test is an experiment on the conductivity of the conductive primer. For the sample, a non-conductive composite panel (plywood such as veneer) is used as a base, and a conductive primer obtained by adding carbon black to a two-component solvent type urethane primer (Part No. P-2080) is applied thereon. Yes. Here, the amount of carbon black added is varied between 0 and 10% by weight.
The evaluation of conductivity was based on a test value using a conductivity indicator (pre-checker) and a minimum voltage value at which current could be confirmed by the pinhole test method described in FIG.

  An electroconductive indicator is an instrument for checking the moisture content of a concrete substrate originally covered with an insulating film (resin lining, waterproof sheet, paint). Before conducting the pinhole inspection of the insulating coating applied on the concrete substrate, the electrical conductivity of the base concrete is evaluated from the surface of the insulating coating using the conductivity indicator.

  The display value of the conductivity indicator indicates the relative dielectric constant εr of the object to be measured (concrete base) of the insulating film. The relative dielectric constant εr is 80 for tap water, 3 to 4 for resin film, and 5 to 6 for concrete aggregate, and the water is overwhelmingly large. The display value of the conductivity indicator increases in proportion to the amount of water contained in the concrete substrate. If the display value of the conductivity indicator is approximately 30 or more, it is determined that the conductivity of the concrete substrate used as the conductive layer at the time of pinhole inspection is sufficient. This time, using this conductivity indicator, the conductivity of the conductive primer was checked.

  Sample No. 1 is a comparative example, and is a measurement value of a non-conductive composite panel to which a conductive primer is not applied. Sample No. 2 is a measured value of a primer without addition of carbon black. Sample No. 3 is a measured value of a conductive primer to which 1% by weight of carbon black was added. The display value of the current-carrying indicator is 19.5, which is the conductivity judgment threshold value 30 or less obtained from the concrete substrate. Even when the waterproof layer is not provided on the surface, the minimum current-carrying voltage requires 6.0 kV. Requires 11 kV.

  Sample No. 4 is a measurement value of a conductive primer in which the amount of carbon black is increased to 5% by weight. The display value of the conductive indicator is 80.5, which exceeds the threshold value 30, and the lowest voltage when the waterproof layer is not provided on the surface of the composite panel is 0.1 kV, and 4-5 kV when the waterproof layer is provided. Sample No. 5 is a measurement value of a conductive primer in which carbon black is increased to 10% by weight. The display value of the conductive indicator was 100 or more, the lowest voltage when the waterproof layer was not provided on the surface of the composite panel was 0.1 kV, and 4 kV when the waterproof layer was provided.

  From the above results, it was found that carbon black contained in the primer at 5% by weight or more, preferably 10% by weight, functions as a conductive layer for pinhole inspection.

(2) Confirmation test Based on the results of the preliminary test, a confirmation test was conducted with a conductive primer containing 10% by weight of carbon black. The base of the sample is the same urethane foam plate as the heat-insulating molded plate 16 used for the ceiling surface shown in FIGS. 2A and 2B, and a conductive primer is sprayed thereon, and the polyurea resin same as the waterproof layer 14 is about 2 mm thick. It is sprayed with. Prior to spraying the waterproof layer, nails and toothpicks were stabbed and removed after spraying to form a pseudo pinhole in the waterproof layer. As a comparative example, a sample without a conductive primer was prepared.

  As a result of the confirmation test, pinhole inspection is possible using a voltage source of 5 kV or higher by using a conductive primer containing 10% by weight of carbon black in the layer structure of the heat insulating layer shown in FIGS. 2A and 2B. It has been found. Furthermore, sample No. As shown in FIG. 3, even if the carbon black is 1% by weight, if a voltage of 11 kV is applied, a pinhole inspection becomes possible, so the maximum voltage value was set to 11 kV. That is, the voltage value used for the pinhole inspection may be 11 kV or less even in the strictest inspection.

  Similarly, when the base is a heat insulating layer (on-site foamed urethane heat insulating material having a thickness of about 30 mm) 18 used on the wall surface and floor surface shown in FIGS. 2A and 2B, the surface is uneven, but the conductive primer is placed in a plurality of directions. The same result was obtained by forming on the whole surface of a heat insulation layer by apply | coating or spraying from.

(Comparison with other construction methods)
As another construction method capable of inspecting pinholes, there is a thermostock construction method shown in FIG. A polystyrene foam heat insulating material 31 is affixed to the inner peripheral surface of the concrete housing 5 using a heat insulating material fixing anchor 36. (Styrofoam) (factory product) is used as the heat insulating material 31. An aluminum sheet 32 is coated on the inner surface of the heat insulating material 31 in advance. On the aluminum sheet 32, a waterproof layer 34 of ultrafast curing urethane is sprayed and applied. The aluminum sheet 32 becomes a conductive layer for pinhole inspection.

  Aluminum is inorganic and does not transmit water vapor at all. On the other hand, the ultrafast curing urethane waterproof layer 34 allows water vapor to pass therethrough. As a result, the water vapor that has passed through the waterproof layer 34 may stop moving in front of the aluminum sheet and condense. It accumulates as condensed water between the waterproof layer 34 and the aluminum sheet 32. It gradually accumulates, causing a peeling phenomenon between the two layers, and may fall.

On the other hand, the configuration of the heat storage tank according to the present embodiment includes heat insulating layers 16 and 18, a conductive layer 17 thereon, and a waterproof layer 14 thereon. Unlike the aluminum sheet, the conductive primer layer forming the conductive layer 17 transmits water vapor.
Water vapor that penetrates the waterproof layer 34 passes through the conductive layer 17 and reaches the heat insulating layers 16 and 18. Since the heat insulation layers 16 and 18 are relatively thick, they absorb this water vapor. However, it is expected that the heat insulating layers 16 and 18 that gradually absorbed water vapor will gradually deteriorate the heat insulating performance within the range of aging.

  As a result of comparing the advantages and disadvantages of the two, the inventors have adopted the layer structure shown in FIG. 2A and FIG. 2B, in which heat-insulating aging is expected, but there is no risk of the waterproof layer falling due to delamination. is there.

[Alternative examples]
As mentioned above, although embodiment of the thermal storage tank which can perform the pinhole test | inspection based on this invention was described, these are illustrations and do not limit this invention. Additions, changes, deletions, changes, improvements, and the like that can be easily made by those skilled in the art to the present embodiment are included in the present invention. Accordingly, the technical scope of the present invention is defined by the description of the appended claims.

1: building, 2: space, 3: heat source machine, 4: heat storage tank, 5: floor slab, concrete slab, concrete frame, 6: foundation slab, concrete frame, 7: wall concrete frame, concrete frame, 8: heat insulating material , 9: waterproof material, 14, 14s, 14u: waterproof layer, 16: heat-insulating molded plate, heat-insulating layer, 17, 17s, 17u: conductive layer, 18: heat-insulating layer, 20: chilled water dedicated tank, 22: ice heat storage tank, 24: Hot water dedicated tank, 26: Cold / hot water tank, 30: Pinhole inspection jig, inspection jig, 31: Polystyrene foam heat insulating material, heat insulating material, 32: Aluminum sheet, sheet, 34: Super fast curing urethane waterproof layer, waterproof layer , 36: anchor for fixing a heat insulating material,
I: ammeter, V: voltage source, Sd: arrow, Sd1: arrow, Sd2: arrow

Claims (6)

Concrete frame,
A heat insulating layer formed of an in-situ foamed urethane heat insulating material formed on the inner surface of the concrete frame;
A conductive layer formed on the inner surface of the heat insulating layer;
A heat storage tank capable of pinhole inspection, comprising a waterproof layer made of polyurea resin formed on the inner surface of the conductive layer. Concrete frame,
A heat insulating layer formed of a heat insulating molded plate formed on the inner surface of the concrete frame;
A conductive layer formed on the inner surface of the heat insulating layer;
A heat storage tank capable of pinhole inspection, comprising a waterproof layer made of polyurea resin formed on the inner surface of the conductive layer. In the heat storage tank capable of pinhole inspection according to claim 1 or 2,
The conductive layer is a heat storage tank that can be inspected by a pinhole, and is made of a primer mixed with a conductive material. In the heat storage tank in which pinhole inspection according to any one of claims 1 to 3 is possible,
A heat storage tank capable of performing pinhole inspection, wherein the conductive material mixed in the conductive layer is made of powdered, particulate or fibrous metal or carbon. In the thermal storage tank in which the pinhole test | inspection as described in any one of Claims 1-4 is possible,
The heat storage tank capable of pinhole inspection, wherein the conductive layer is a urethane primer mixed with at least 5% by weight of carbon black. In the heat storage tank in which the pinhole inspection according to claim 3 is possible,
A heat storage tank capable of pinhole inspection, wherein a voltage applied to the conductive layer at the time of pinhole inspection is 5 to 11 kV.

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