JP2020134394A - Performance change prediction system of vacuum insulation material and program - Google Patents

Abstract

To solve a problem in the monitoring of a vacuum insulation material by a conventional embodiment that a decision is merely made whether or not the thermal insulation performance of the vacuum insulation material at the point of measurement is lowered on the basis of various measured values such as temperature and vacuum (internal pressure) obtained from a sensor, and it is difficult to predict a thermal insulation performance change of the vacuum insulation material several years later in consideration of the measured value change to obtained from the vacuum insulation material for time series.SOLUTION: According to the present invention, a thermal insulation performance change prediction system is capable of: periodically acquiring measurement data from a built-in sensor of a vacuum insulation material, and accumulating the data in a storage device for time series along with a measurement date; calculating an inside pressure value (internal pressure value) from the accumulated measurement data; dividing a difference between a latest internal pressure value and a past internal pressure value, by measurement intervals (e.g., observation days) of the measurement data corresponding to those internal pressure values to calculate a pressure gradient; predicting the change of the thermal insulation performance of the vacuum insulation material several years later or after them, on the basis of the calculated pressure gradient; and presenting a replacement timing of the vacuum insulation material or an alert to a user.SELECTED DRAWING: Figure 4

Description

The present invention acquires measurement data from long-term internal pressure measurement of a vacuum heat insulating material used for an outer wall of a house or a plant, and represents a long-term performance change in thermal conductivity and internal pressure from the measurement data for a certain period of time. A system and program that calculates the evaluation value and predicts the change in heat insulation performance of the vacuum heat insulating material installed on the outer wall of the house or plant after several years based on the performance evaluation value (hereinafter, "heat insulation performance change prediction system, etc." ”). Specifically, the present invention relates to a vacuum heat insulating material heat insulating performance change prediction system suitable for notifying customers, contractors, etc. of the current heat insulating performance and replacement timing of the vacuum heat insulating material by alert or the like.

The vacuum heat insulating material is widely used in various fields such as refrigerators, thermos bottles, and outer walls of houses and plants as a heat insulating material having higher heat insulating performance than Styrofoam. In this vacuum heat insulating material, for example, a core material made of a porous body having many voids inside is covered with a bag-shaped gas barrier film that encloses the core material to reduce the pressure, and the opening of the gas barrier film is heat-welded ( It can be heat-sealed) and provided with an outer layer on the outside of the gas barrier film.

In general, vacuum heat insulating materials installed on the outer walls of houses and plants deteriorate over time due to long-term operation, and gas such as air gradually flows into the interior from the outside over a long period of time. Insulation performance deteriorates due to the inflow of gas. Therefore, a device that provides a temperature sensor, a vacuum sensor, etc. in the vacuum heat insulating material, monitors the performance of the vacuum heat insulating material for a long period of time, and detects a change in the performance of the vacuum heat insulating material has been proposed as a conventional technique. ..

For example, in the vacuum heat insulating panel described in Japanese Patent No. 4641565 (Patent Document 1), the core material is covered with a gas barrier exodermis material, and the measurement results by the temperature sensor unit and the temperature sensor unit capable of measuring the surrounding temperature are obtained. The communication unit capable of wireless communication and the battery are configured to be arranged inside the outer skin material. Further, the vacuum heat insulating panel described in Japanese Patent Application Laid-Open No. 2012-136254 (Patent Document 2) is a heat insulating panel in which the heat insulating material is covered with a gas barrier film and the inside is evacuated, and at least a vacuum sensor is provided inside the outer skin material. A communication unit that can transmit the vacuum data detected by the vacuum sensor to the outside and a battery are provided.

These conventional vacuum heat insulating materials (vacuum heat insulating panels) can measure the degree of vacuum of the vacuum heat insulating material and the ambient temperature by a built-in sensor, and transmit the measurement data to an external device by wireless communication. The heat insulating performance of the vacuum heat insulating material can be monitored in the external device that received the measurement data. As a result, the customer or the contractor who uses the external device can know the performance of the vacuum heat insulating material at the time of measurement by the sensor.

Japanese Patent No. 4641565 Japanese Unexamined Patent Publication No. 2012-136254

However, in the monitoring of the vacuum heat insulating material according to the above-mentioned conventional example, whether or not the heat insulating performance of the vacuum heat insulating material at the time of measurement is simply deteriorated based on various measured values such as temperature and vacuum (internal pressure) obtained from the sensor. It was difficult to predict the change in the heat insulating performance of the vacuum heat insulating material several years later by considering the change in the measured value obtained from the vacuum heat insulating material in chronological order.

Therefore, in the present invention, the measurement data is periodically acquired from the built-in sensor of the vacuum heat insulating material, accumulated in the storage device in chronological order with the measurement date and time, and the internal pressure value (internal pressure value) is stored from the accumulated measurement data. Calculate and calculate the difference between the latest internal pressure value and the past internal pressure value, and the measurement interval of the measurement data corresponding to those internal pressure values (for example, the date when the latest measurement data was accumulated and the past measurement data were accumulated. By calculating the pressure gradient, which is an example of the performance evaluation value, by dividing by the number of days, which is the difference from the day, the change in the heat insulating performance after several years of the vacuum heat insulating material or after that based on the calculated pressure gradient. It is possible to predict and provide alerts regarding the replacement timing of the vacuum heat insulating material and the current heat insulating property to those who monitor changes in the long-term heat insulating performance of the vacuum heat insulating material (constructors, manufacturers, etc.). Provide a heat insulation performance change prediction system and the like.

As one embodiment of the heat insulating performance change prediction system according to the present invention, the core material, the gas barrier film covering the core material, and the outer layer provided on the outside of the gas barrier film are included, and the inside is vacuum-sealed. A small radio pressure gauge provided inside the outer layer of the vacuum heat insulating material, obtained from a small radio pressure gauge including at least a pressure sensor and a transmission unit for transmitting measurement data measured by the pressure sensor. A storage unit that stores measurement data and
From the measurement data, the internal pressure value indicating the internal pressure of the vacuum heat insulating material at the time of measurement by the pressure sensor is obtained, and the internal pressure difference between the internal pressure value and the past internal pressure value representing the past internal pressure of the vacuum heat insulating material. And a pressure gradient calculation unit that acquires a pressure gradient value that represents the amount of change in the internal pressure difference per unit time.
A performance determination unit that determines the heat insulating performance of the vacuum heat insulating material when a predetermined designated period has elapsed based on the thermal conductivity converted from the pressure gradient value.
Including a notification unit that gives a notification according to the determination result by the performance determination unit.
The performance determination unit determines whether or not the thermal conductivity is equal to or higher than a predetermined thermal conductivity specified in advance.
The notification unit is characterized in that when the performance determination unit determines that the thermal conductivity is equal to or higher than the designated thermal conductivity, the notification unit prompts the replacement of the vacuum heat insulating material.

As a preferred embodiment of the heat insulation performance change prediction system according to the present invention, the pressure gradient value is calculated by a mathematical formula (1) described later.

As a preferred embodiment of the heat insulation performance change prediction system according to the present invention, the thermal conductivity is calculated by a mathematical formula (2) described later.

As a preferred embodiment of the heat insulation performance change prediction system according to the present invention, the value t representing the replacement time in the mathematical formula (2) described later is a value of the predetermined designated period.

As a preferred embodiment of the heat insulation performance change prediction system according to the present invention, the replacement time is calculated by the mathematical formula (3) described later.

As a preferred embodiment of the heat insulation performance change prediction system according to the present invention, λ _cop in the mathematical formula (3) described later is a value of the designated thermal conductivity specified in advance.

As a preferred embodiment of the heat insulating performance change prediction system according to the present invention, the notification unit is characterized in that the period or time until the thermal conductivity of the vacuum heat insulating material reaches the designated thermal conductivity is notified. ..

As a preferred embodiment of the heat insulating performance change prediction system according to the present invention, the notification unit reaches the designated thermal conductivity when the performance determining unit determines that the thermal conductivity is less than the designated thermal conductivity. It is characterized by notifying the period or time until the operation.

As a preferred embodiment of the heat insulation performance change prediction system according to the present invention, the performance determination unit further includes a current value of the thermal conductivity λ _cop and one or more past values acquired in the past by the performance determination unit. It is determined whether or not the correlation coefficient of is equal to or greater than the specified correlation coefficient specified in advance.
The notification unit is characterized in that when the performance determination unit determines that the correlation coefficient is less than the designated correlation coefficient, it notifies a notification prompting the replacement of the vacuum heat insulating material or a warning notifying an abnormality. To do.

As a preferred embodiment of the heat insulation performance change prediction system according to the present invention, the correlation coefficient is calculated by the mathematical formula (4) described later, where the current value of the thermal conductivity λ _cop is X and the past value is Y. It is characterized by being done.

As one embodiment of the heat insulation performance change prediction program according to the present invention, a computer is made to function as the heat insulation performance change prediction system.

The heat insulating performance change prediction system according to one embodiment of the present invention uses a built-in sensor of the vacuum heat insulating material to periodically monitor the difference between the latest internal pressure value of the vacuum heat insulating material and the past internal pressure value. By providing a pressure gradient calculation unit that calculates the pressure gradient by dividing by the number of monitoring days from to the latest, the change in heat insulation performance after several years of the vacuum heat insulating material or after that is based on the calculated pressure gradient. It becomes possible to predict. Further, the heat insulating performance change prediction system according to one embodiment of the present invention provides a long-term alert regarding the replacement timing of the vacuum heat insulating material and the current heat insulating property based on the predicted change in the heat insulating performance. It is also possible to present it to those who monitor changes in heat insulation performance (constructors, manufacturers, etc.).

It is a figure which shows the system configuration example for monitoring the vacuum heat insulating material. It is a block diagram which shows the component structure of the small wireless pressure gauge included in the vacuum heat insulating material to be monitored. It is a block diagram which shows the configuration example of the hardware of the computer which functions as the insulation performance change prediction system. It is a block diagram which shows an example of the functional structure of the heat insulation performance change prediction system which concerns on one Embodiment of this invention. It is a figure which shows an example of the display screen of the heat insulation performance change prediction system. It is a flowchart which shows the flow of process which converts the output value acquired from the pressure sensor in a small wireless vacuum gauge into a pressure value. It is a graph which shows the relationship between the pressure sensor in a small wireless vacuum gauge, and the internal pressure of a vacuum heat insulating material. It is a graph which shows the relationship between the thermal conductivity of a vacuum heat insulating material including a glass wool core material, and the internal pressure with the vacuum heat insulating material. It is the graph which showed the graph shown in FIG. 8 and FIG. 9 superimposed. It is a flowchart which shows the flow of the process which determines the heat insulation performance of a vacuum heat insulating material when the designated period elapses based on the thermal conductivity converted from the pressure gradient value. It is a graph which shows the relationship (pressure gradient) between the internal pressure of a vacuum heat insulating material and a period (days).

An embodiment of the present invention will be described below with reference to the drawings. In addition, in all the figures for demonstrating the embodiment, in principle, the same members are designated by the same reference numerals, and the repeated description thereof will be omitted.

FIG. 1 is a diagram showing an example of a system configuration for monitoring the vacuum heat insulating material. The small wireless vacuum gauge 10 is provided in the vacuum heat insulating material 20, and transmits measurement data for calculating an internal pressure value indicating the internal pressure of the vacuum heat insulating material 20 to the server 30 via a network N such as the Internet. be able to.

The small wireless vacuum gauge 10 can transmit measurement data to a mobile terminal (external receiving unit) (not shown) by wireless communication, and the mobile terminal can transmit the measurement data to the server 30 via the network N. .. Further, the small wireless vacuum gauge 10 can be directly connected to the network via Wi-Fi or the like to transmit the measurement data to the server 30 preset as the transmission destination of the measurement data. The terminal 40 is connected to the server 30 via the network N, and is notified about the replacement timing of the vacuum heat insulating material and the current heat insulating property based on the predicted result of the change in the heat insulating performance several years after or after the vacuum heat insulating material. Alerts) etc. can be received and displayed on the screen.

FIG. 2 is a block diagram showing a component configuration of a small wireless vacuum gauge included in the vacuum heat insulating material according to the embodiment of the present invention. The small wireless vacuum gauge 10 includes a pressure sensor 1, an operational amplifier 2, an A / D converter 3, a CPU / wireless transmission unit 4, a temperature / humidity sensor / internal clock 5, a charging unit 6, and a DC / DC converter 7. And the battery 8 can be included.

The pressure sensor 1 measures the pressure inside the vacuum heat insulating material, and the operational capacitor 2 connected to the pressure sensor 1 can amplify an analog signal of the measured pressure value. The A / D converter 3 connected to the operational amplifier 2 converts the amplified analog signal into a digital signal, and the CPU / wireless transmission unit 4 connected to the A / D converter 3 receives the digital signal and receives the digital signal. The signal can be transmitted as measurement data to an external receiving unit (not shown) by a sub-giga band radio of less than 1 GHz, a 2.4 GHz band radio, or a 5 GHz band radio.

The frequency band of the CPU / wireless transmission unit 4 can be selected as long as it is a frequency band capable of wireless transmission, but a range of 1 GHz or less is preferable from the viewpoint of transmission distance. The 920 MHz band uses the ISM band and consumes a large amount of power for one transmission. However, since the 920 MHz band has higher diffractive property than the 2.4 GHz band, it is possible to communicate around obstacles and the radio wave has a long reach, so that the transmission is several meters from the outer layer surface of the vacuum heat insulating material. Is possible.

On the other hand, the 2.4 GHz band communication method including BLE (Bluetooth Low Energy) communication consumes less power, but the range of radio waves is about 5 cm from the outer layer surface of a general vacuum heat insulating material. Although it is difficult to measure when the vacuum heat insulating material is installed inside the wall, it can be used in a place where the wall thickness is thin or when the surface of the vacuum heat insulating material is exposed from the wall.

An external receiving unit can record the measured voltage when it receives the measured data and convert it from a known calibration value (voltage / pressure) conversion value to a pressure value, and the pressure value output by the conversion is, for example, Calculated by the program executed by the receiving unit (server).

As the pressure sensor 1, a thermocouple type vacuum sensor formed by a microelectromechanical system (MEMS) can be used. Further, as the pressure sensor 1, a thermocouple type vacuum sensor formed by MEMS can also be used.

The temperature / humidity sensor / internal clock 5 connected to the CPU / wireless transmission unit 4 can directly transmit a signal to the CPU by serial communication such as I2C communication. The CPU / wireless transmission unit 4 can wirelessly transmit signals from the temperature / humidity sensor / internal clock 5 to an external receiving unit. Even if there is no temperature / humidity sensor, the pressure inside the vacuum heat insulating material can be measured by the pressure sensor 1, so if it is not necessary, it does not need to be included in the configuration of the small wireless vacuum gauge 10. Good. That is, the temperature / humidity sensor can be included in the small wireless vacuum gauge 10 when necessary, such as confirming the problem of the water vapor pressure entering the inside of the vacuum heat insulating material. Further, a sensor for measuring various molecular species (carbon dioxide, carbon monoxide, oxygen, VOC, etc.) can be included in the small wireless vacuum gauge 10. That is, the small wireless vacuum gauge 10 can further include at least one of a temperature sensor, a humidity sensor, a sensor for measuring various molecular species, and an internal clock.

The battery 8 connected to the CPU / wireless transmission unit 4 can supply electric power to the CPU / wireless transmission unit 4 and other components (elements) electrically connected to the unit. Further, the battery 8 is connected to the charging unit 6 via the DC / DC converter 7, and the charging unit 6 can supply electric power for charging the battery 8. The DC / DC converter 7 can convert the voltage obtained from the charging unit 6 into the voltage required for charging the battery 8.

The DC / DC converter 7 is not originally essential for charging the battery 8 of the small wireless vacuum gauge 10. The DC / DC converter 7 is configured to minimize the influence of dielectric loss that may occur due to the induction of dielectric heating when charging is performed through the metallic gas barrier film of the vacuum heat insulating material. .. That is, when such dielectric heating is caused, it becomes difficult to supply the required electric power. Therefore, by using the DC / DC converter 7, it is possible to boost the voltage to the required voltage.

When a higher voltage is applied, the heat generated on the surface of the vacuum heat insulating material becomes large, which may damage the gas barrier film composed of the resin and the metal layer or dissolve the resin film. In such a case, the vacuum heat insulating material cannot maintain the vacuum, and the heat insulating property is greatly impaired. Therefore, driving the sensor via the DC / DC converter 7 is a more preferable configuration when operating inside the vacuum heat insulating material.

The charging unit 6 can employ a Peltier element or a coil for non-contact power feeding as a charging mechanism. When a Peltier element is used as the charging mechanism of the charging unit 6, the electric power generated by the Seebeck effect can be supplied to the battery 8 via the DC / DC converter 7 by applying heat to the Peltier element. .. For example, when a small lithium ion polymer (LiPo) battery of 85 mAh is adopted as the battery 8, charging of the small LiPo battery is completed by applying heat of 80 ° C. to the Peltier element of the charging unit 6 for about 5 minutes. can do. The vacuum heat insulating material can be charged with almost no damage if heat of 80 ° C. is applied for about 5 minutes.

When the charging unit 6 uses a coil for non-contact power feeding as the charging mechanism, the charging unit 6 can supply the electric power generated by the electromagnetic induction method or the magnetic field resonance method to the battery 8 via the DC / DC converter 7. For example, in the case of the electromagnetic induction method, the charging unit 6 includes a power receiving side coil, and uses the dielectric magnetic flux generated between the power transmitting side coil and the power receiving side coil included in the charger or the like outside the vacuum heat insulating material. The electric power generated in the process can be received by the charging unit 6.

Further, in the case of the electric field resonance method, the power receiving side coil is included in the power receiving side resonance circuit, and the power transmission side coil is included in the power transmission side resonance circuit. The vibration of the magnetic field generated by the current flowing through the transmitting side coil included in the charger transmitting side resonance circuit is transmitted to the receiving side coil included in the receiving side resonance circuit that resonates at the same frequency, causing magnetic field resonance. The generated power can be received by the charging unit 6.

The small wireless vacuum gauge 10 is provided inside the vacuum heat insulating material that is sealed under reduced pressure. The vacuum heat insulating material includes a core material, a gas barrier film covering the core material, and an outer layer provided on the outside of the gas barrier film, and the small wireless vacuum gauge 10 is inside the outer layer of the vacuum heat insulating material. Preferably, it is contained inside the gas barrier film.

As described above, the small wireless pressure gauge 10 is provided with a charging unit including a charging mechanism capable of charging the battery without being electrically connected to an external power source, so that the small wireless vacuum gauge 10 is built in the vacuum heat insulating material. However, it is possible to continuously supply sufficient power that can withstand long-term operation.

As the core material of the vacuum heat insulating material, those used in the vacuum heat insulating material field can be used without particular limitation. As a specific example, open cell rigid polyurethane foam, inorganic fiber, organic fiber, inorganic powder, airgel and the like can be used. From the viewpoint of handling and heat insulating properties, sheet-shaped inorganic fibers are preferable. Examples of the inorganic fiber include glass fiber, ceramic fiber such as alumina and silica, slag wool fiber, and rock wool fiber. Among these, glass fiber is preferable from the viewpoint of heat insulating property, molding processability and the like. In order to improve the heat resistance of the core material, a small amount of heat-resistant metal fibers such as stainless steel, chromium-nickel alloy, high nickel alloy, and high cobalt alloy can be mixed. Core materials are known and are readily available or available on the market.

In the vacuum heat insulating material according to the embodiment of the present invention, the adsorbent may be enclosed in a bag-shaped gas barrier film together with the core material. The adsorbent is, for example, a substance that adsorbs gases such as nitrogen, oxygen, and carbon dioxide, and / or water. Examples of the adsorbent include calcium oxide, silica gel, zeolite, activated carbon, barium oxide, barium-lithium alloy, or a mixture thereof. Calcium oxide is preferable from the viewpoint of gas adsorption performance and productivity. Adsorbents are known and are readily available or available on the market.

The gas barrier film used in the present invention is not particularly limited as long as it is a film having gas barrier properties, but a film in which a seal layer and a gas barrier layer are laminated is preferable, and the seal layer, the gas barrier layer and 1 are in order from the side in contact with the core material. It is more preferable that a resin film layer having more than one layer is laminated. The thickness of the gas barrier film is not particularly limited, but is usually 50 to 200 μm, preferably 60 to 180 μm.

The gas barrier layer is a layer that does not allow gas to permeate, and is used from the viewpoint of preventing a decrease in the degree of vacuum of the vacuum heat insulating material. Examples of the gas barrier layer include a metal foil, a thin-film film in which a thin-film film is formed on a resin film, and the like. The thin-film deposition film is obtained by forming a thin-film deposition film on a substrate by a vapor deposition method, a sputtering method, or the like. From the viewpoint of gas barrier property and economy, aluminum is preferably used in both the metal foil and the vapor deposition material.

Examples of the resin film used as the base material of the vapor-deposited film include aromatic polyester-based resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyolefin-based resins such as polyethylene, polypropylene and olefin copolymers; polyvinyl chloride, Vinyl chloride-based resins such as vinyl chloride copolymers; polyamide resins such as nylon 6, nylon 66, metaxylylene diamine / adipic acid condensate; styrenes such as acrylonitrile / butadiene / styrene copolymers and acrylonitrile / styrene copolymers. Based resin: Acrylic resin such as polymethylmethacrylate, acrylic acid ester and methylmethacrylic acid ester copolymer, ethylene-vinyl alcohol copolymer, thermoplastic resin such as polyvinyl alcohol and partially saponified product of polyvinyl acetate, A film produced from a thermocurable resin such as a phenol resin or a urea resin is used.

The thickness of the gas barrier layer is not particularly limited, but in the case of a metal foil, it is 1 to 60 μm, preferably 5 to 30 μm. When the thickness is 1 μm or more, the strength of the metal foil is high and the formation of pinholes can be suppressed. In the case of the thin-film deposition film, the thickness of the gas barrier layer is 10 to 60 μm, preferably 12 to 30 μm, of which the thickness of the thin-film deposition film is 0.2 to 3.0 μm, preferably 0.5 to 2.0 μm. Is. If the thickness of the vapor-deposited film is 0.2 μm or more, the gas barrier property can be exhibited, and if it is 3.0 μm or less, the technical difficulty of forming the thin-film film is not great. Metal foils and vapor-deposited films used for gas barrier layers are known and are readily available or available on the market.

The seal layer is a resin that can be fused by heating. There is no particular limitation as long as it is a heat-bondable resin. Specifically, a film composed of a polyolefin resin such as polyethylene and polypropylene, polyacrylonitrile, PET, an ethylene-vinyl alcohol copolymer, or a mixture thereof can be used. Preferably, polyethylene, polypropylene, or ethylene-vinyl alcohol copolymer is used. The polyethylene preferably has a density of 0.99 to 0.98 g / cm ³ . The polypropylene preferably has a density of 0.85 to 0.95 g / cm ³ . The thickness of the seal layer is not particularly limited, but is usually 10 to 100 μm, preferably 25 to 60 μm. The resins used for the seal layer are known and are readily available or available on the market.

The resin film layer is a layer arbitrarily provided on the gas barrier layer for the purpose of protecting the gas barrier layer. Examples of the resin film layer include aromatic polyester-based resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyolefin-based resins such as polyethylene, polypropylene and olefin copolymers; polyvinyl chloride and vinyl chloride copolymers. Vinyl chloride resin; Polyethylene resin such as nylon 6, nylon 66, metaxylylene diamine / adipic acid condensate; styrene resin such as polyvinyl alcohol, acrylonitrile / butadiene / styrene copolymer, acrylonitrile / styrene copolymer; A film produced from a thermoplastic resin such as an acrylic resin such as polymethyl methacrylate, an acrylic acid ester and a methyl methacrylate ester copolymer, or a thermosetting resin such as a phenol resin or a urea resin is used. Preferably, it is PET, nylon 6 or nylon 66. Organic and inorganic fillers can also be added to these resin films. These resins can be used alone or in admixture of two or more. In order to further improve the gas barrier performance of the gas barrier film, the resin film layer is coated with or laminated with a gas barrier resin obtained by polymerizing and copolymerizing vinyl monomers such as vinylidene chloride, acrylonitrile, and vinyl alcohol. , Those particles can also be mixed and dispersed in the resin film layer. The thickness of the resin film layer is not particularly limited, but is usually 5 to 40 μm, preferably 10 to 30 μm. The resin used for the resin film layer is known and can be easily obtained or prepared on the market.

The gas barrier film is formed in a bag shape. The bag shape is a shape in which a core material and an adsorbent can be put. The step of forming the gas barrier film into a bag shape is not particularly limited. For example, when the gas barrier film has a seal layer, two gas barrier films are stacked so that the seal layers are in contact with each other, and the core material and the adsorbent are inserted around the portion where the core material and the adsorbent are stored. The gas barrier film may be formed in a bag shape by heat-sealing leaving an opening for the film.

Paper and / or non-woven fabric can be laminated on the outer layer of the gas barrier film for vacuum heat insulating material used in the present invention. Paper is a product produced by sticking plant fibers and other fibers together. Both organic fibers and inorganic fibers can be used as paper materials. Examples of organic fibers used as a material for paper include plant-derived fibers and synthetic fibers, and examples of inorganic fibers used as a material for paper include fibers made of minerals and metals, synthetic fibers and the like. A non-woven fabric is a fiber sheet, web or bat in which the lines are oriented in one direction or randomly, and the fibers are bonded by alternating current and / or fusion and / or adhesion. Both organic fibers and inorganic fibers can be used as materials for non-woven fabrics.

Organic fibers used as materials for non-woven fabrics include natural fibers and chemical fibers, natural fibers include cotton, wool, felt, linen, pulp, silk, etc., and chemical fibers include rayon, polyamide, polyester, polypropylene, acrylic fiber, etc. There are vinylon, aramid fiber, acetate, etc. Examples of inorganic fibers used as raw materials for non-woven fabrics include glass fibers, carbon fibers, and mineral fibers. Preferred materials are polyamide, polyester and polypropylene. Paper and non-woven fabrics are known and are readily available or available on the market.

The thickness of the outer layer is 0.01 mm to 3 mm, preferably 0.03 to 0.5 mm. The basis weight of the outer layer is not particularly limited, but is preferably 10 to 200 g / m ² , and more preferably 20 to 100 g / m ² .

The outer layer is adhered to the side of the gas barrier film that does not contact the core material (outside of the vacuum heat insulating material) by, for example, laminating. Examples of the laminating method include dry laminating, extruding laminating, hot melt laminating, wet laminating, and thermal laminating.

The shape of the vacuum heat insulating material is, for example, a plate shape. The plate shape refers to a thin and flat shape, and has two opposing surfaces and a side peripheral surface connecting the two surfaces. The outer layer covers at least a part of one surface of the plate-shaped vacuum heat insulating material, and preferably covers the edge of the surface arranged on the heat source side in a frame shape during use. The outer layer preferably also covers the side peripheral surface of the vacuum heat insulating material, and more preferably covers the entire surface of the vacuum heat insulating material (that is, both sides and the side peripheral surface). Further, when a plurality of vacuum heat insulating materials are used in combination, it is advantageous to cover the side peripheral surface with an outer layer in order to prevent heat leakage at the joint portion between the vacuum heat insulating materials.

FIG. 3 is a block diagram showing a configuration example of computer hardware that functions as a heat insulation performance change prediction system. In the figure, the code corresponding to the hardware of the server 30 is described without parentheses, and the code corresponding to the hardware of the terminal 40 is described with parentheses.

The server 30 is exemplified by a memory 33 including a CPU (Central Processing Unit) 31, a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, a bus 34, an input / output interface 35, and an input unit 36. An output unit 37, a storage unit 38, and a communication unit 39 are provided.

The CPU 31 executes various processes according to the program recorded in the memory 33 or the program loaded from the storage unit 38 into the memory 33. The CPU 31 can execute, for example, a program for making the server 30 function as the heat insulation performance change prediction system of the present invention. Further, at least a part of the functions of the heat insulation performance change prediction system can be implemented in hardware by an integrated circuit (ASIC) or the like for a specific application.

Data and the like necessary for the CPU 31 to execute various processes are also appropriately stored in the memory 33. The CPU 31 and the memory 33 are connected to each other via the bus 34. An input / output interface 35 is also connected to the bus 34. An input unit 36, an output unit 37, a storage unit 38, and a communication unit 39 are connected to the input / output interface 35.

The input unit 36 is composed of various buttons, a touch panel, a microphone, or the like, and inputs various information in response to an instruction operation by the administrator of the server 30 or the like. The input unit 36 may be realized by an input device such as a keyboard or a mouse, which is independent of the main body that houses the other parts of the server 30.

The output unit 37 is composed of a display, a speaker, and the like, and outputs image data and music data. The image data and music data output by the output unit 37 are recognizable by the player as images and music from a display, a speaker, or the like.

The storage unit 38 is composed of a semiconductor memory such as a DRAM (Dynamic Random Access Memory) and stores various data.

The communication unit 39 realizes communication with other devices. For example, the communication unit 39 communicates with the terminal 40 via the network N.

Although not shown, the server 30 is appropriately provided with a drive as needed. For example, a removable medium composed of a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like is appropriately mounted on the drive. The removable media stores various data such as a program for executing a game and image data. Various data such as programs and image data read from the removable media by the drive are installed in the storage unit 38 as needed.

Next, the hardware configuration of the terminal 40 will be described. As shown in FIG. 2, the terminal 40 is exemplified by a CPU 41, a memory 43, a bus 44, an input / output interface 45, an input unit 46, an output unit 47, a storage unit 48, and a communication unit 49. And have. Each of these parts has the same function as each part of the same name provided in the above-mentioned server 30, which differs only in the code. Therefore, duplicate description will be omitted. When the terminal 40 is configured as a portable device, each hardware included in the terminal 40 may be realized as an integrated device such as a display and a speaker.

(Functional configuration)
FIG. 4 is a block diagram showing an example of the functional configuration of the heat insulation performance change prediction system according to the embodiment of the present invention. FIG. 4 is a block diagram showing a functional configuration for executing a process such as a heat insulation performance change prediction process among the functional configuration of the server 30 and the functional configuration of the terminal 40 shown in FIG.

Here, the heat insulation performance change prediction process is a time-series time-series internal pressure value (internal pressure value) obtained by converting measurement data repeatedly acquired from the vacuum heat insulating material to be monitored at time intervals. This is a process for predicting changes in the long-term heat insulating performance of the vacuum heat insulating material using an index (pressure gradient) based on the change. The specific contents of the processing will be described later in the description of the flowcharts shown in FIGS. 5 and 6.

When a program that realizes the heat insulation performance change prediction process is executed, the server 30 functions in the CPU 31, the pressure gradient calculation unit 311, the performance determination unit 312, and the notification unit 313, as shown in FIG. Further, in a part of the storage area of the storage unit 38, the measurement data storage unit 381 that stores the measurement data acquired from the vacuum heat insulating material to be monitored, and the value of the measurement data are the value of the internal pressure of the vacuum heat insulating material (internal pressure). The internal pressure value storage unit 382 converted into the value) is included.

Communication with the terminal 40 by the heat insulation performance change prediction process is performed using the communication unit 39 of the server 30 and the communication unit 49 of the terminal 40. As shown in FIG. 1, there is a network N for realizing communication between the server 30 and the terminal 40, but the illustration of the network N is omitted in FIG.

The measurement data storage unit 381 was measured by a pressure sensor 1 (see FIG. 2) acquired from a small wireless vacuum gauge 10 provided for monitoring the internal state of the vacuum heat insulating material 20 as shown in FIG. The measurement data is accumulated in association with the measurement time. The pressure gradient calculation unit 311 obtains an internal pressure value indicating the internal pressure of the vacuum heat insulating material 20 at the time of measurement by the pressure sensor 1 from the measurement data measured by the pressure sensor 1, and obtains the obtained internal pressure value as the measurement data (and / Alternatively, it can be stored in the internal pressure value storage unit 382 in association with the measurement time).

ただし、ΔPa は、前記圧力勾配値であり、Pa_c は計測時点での前記真空断熱材の前記内圧値であり、Pa_a は Pa_c よりも過去に計測された前記過去内圧値であり、Day は Pa_a の計測時点から Pa_c の計測時点までの測定間隔を表す日数である。 Further, the pressure gradient calculation unit 311 refers to the internal pressure value storage unit 382, and refers to the internal pressure value at a predetermined measurement time point and the internal pressure value of the past internal pressure value representing the value of the internal pressure of the vacuum heat insulating material in the past. The difference is calculated, and the pressure gradient value representing the amount of change in the internal pressure difference per unit time is acquired. The pressure gradient value is calculated by the following mathematical formula (1).

However, ΔPa is the pressure gradient value, Pa _c is the internal pressure value of the vacuum heat insulating material at the time of measurement, Pa _a is the past internal pressure value measured earlier than Pa _c , and Day. Is the number of days representing the measurement interval from the time of measurement of Pa _{a to} the time of measurement of Pa _c .

ただし、λ_cop は真空断熱材の中央部の熱伝導率であり、λ_sr は雰囲気圧力である Pa が 1Pa 以下の時の芯材の固体及び放射熱伝導率であり、λ_ga は乾燥空気の熱伝導率であり、P_1/2 は芯材の大気圧下での熱伝導率の値と、真空下（1Pa以下）での熱伝導率の値を足して２で割った熱伝導率の時の雰囲気圧力値、ｔ は、交換時期を表す値である。なお、交換時期を表す値 ｔ は、予め指定された指定期間の値とすることができる。 The performance determination unit 312 can determine the heat insulating performance of the vacuum heat insulating material when a predetermined designated period has elapsed, based on the thermal conductivity converted from the pressure gradient value. The thermal conductivity is calculated by the following mathematical formula (2). In the formula (2), it is necessary to obtain λ _sr, λ _ga , and P _1/2 in advance for each material used for manufacturing the vacuum heat insulating material.

However, λ _cop is the thermal conductivity of the central part of the vacuum insulation material, λ _sr is the solid and radiated thermal conductivity of the core material when the atmospheric pressure Pa is 1 Pa or less, and λ _ga is the dry air. It is the thermal conductivity, and P _1/2 is the value of the thermal conductivity of the core material under atmospheric pressure and the value of the thermal conductivity under vacuum (1 Pa or less) added and divided by 2. Atmospheric pressure value at time, t is a value indicating the replacement time. The value t indicating the exchange time can be a value of a designated period specified in advance.

For the vacuum heat insulating material used in the present invention, it is desirable to grasp the relationship between the thermal conductivity and the internal pressure by the mathematical formula (2) before incorporating the sensor into the product. As a measurement method, the thermal conductivity of the vacuum heat insulating material incorporating the sensor is measured based on the heat flow meter method (JIS-1412 PartII), and the formula (2) is the relational expression between the thermal conductivity and the pressure from the pressure at that time. There is a way to get.

ただし、ｔ は、交換時期を表す値であり、λ_cop は真空断熱材の中央部の熱伝導率であり、λ_sr は雰囲気圧力である Pa が 1Pa 以下の時の芯材の固体及び放射熱伝導率であり、λ_ga は乾燥空気の熱伝導率であり、P_1/2 は芯材の大気圧下での熱伝導率の値と、真空下（1Pa以下）での熱伝導率の値を足して２で割った熱伝導率の時の雰囲気圧力値である。なお、 λ_cop は、予め指定された指定熱伝導率の値とすることができる。 The replacement time is calculated by the following formula (3).

However, t is a value _indicating the replacement time, λ _cop is the thermal conductivity of the central part of the vacuum insulation material, and λ _sr is the atmospheric pressure, which is the solid and radiated heat of the core material when Pa is 1 Pa or less. It is the conductivity, λ _ga is the thermal conductivity of dry air, and P _1/2 is the value of the thermal conductivity of the core material under atmospheric pressure and the value of the thermal conductivity under vacuum (1 Pa or less). It is the atmospheric pressure value at the time of the thermal conductivity obtained by adding and dividing by 2. Note that λ _cop can be a value of a specified thermal conductivity specified in advance.

The notification unit 313 can notify the period or time until the thermal conductivity of the vacuum heat insulating material reaches the designated thermal conductivity designated in advance. Further, the notification unit 313 can also notify the period or time until the designated thermal conductivity is reached when the performance determination unit 312 determines that the thermal conductivity of the vacuum heat insulating material is less than the designated thermal conductivity. .. Further, the notification unit 313 determines in the performance determination unit 312 that the thermal conductivity of the vacuum heat insulating material exceeds the designated thermal conductivity.
You can be notified of alerts. For example, the notification unit 313 reaches the output unit 47 of the monitor or the like of the terminal 40 via the communication unit 39, and the thermal conductivity of the vacuum heat insulating material reaches the designated thermal conductivity according to the determination result of the performance determination unit 312. It is possible to display the period or time until the prediction result as a prediction result, display an alert notifying the deterioration of the heat insulating performance, and the like.

The performance determination unit 312 further determines the correlation coefficient between the current value of the thermal conductivity λ _cop calculated by the above-mentioned mathematical formula (2) and one or more past values acquired in the past by the performance determination unit 312. It is possible to determine whether or not the correlation coefficient is equal to or greater than the specified correlation coefficient specified in advance. The correlation coefficient is calculated by the following mathematical formula (4), where the current value of the thermal conductivity λ _cop is X and the past value is Y.

When the performance determination unit 312 determines that the correlation coefficient is less than the specified correlation coefficient specified in advance, the notification unit 313 can give a notification prompting the replacement of the vacuum heat insulating material or a warning notification of an abnormality. ..

The terminal 40 can display the display screen as shown in FIG. 5 on the output unit 47 by executing the browser program 411 by the CPU 41. FIG. 5 is a diagram showing an example of a display screen of the heat insulation performance change prediction system. For example, in the calibration result substitution column, various parameters of the pressure sensor 1 of the small wireless vacuum gauge 10 (To: sensor output value at atmospheric pressure, Tmax: sensor output value in vacuum state, P _1/2 : sensor output value are It accepts the input of the pressure when it is halved), and also various parameters of the core material (λsr: thermal conductivity of dry air, λga: thermal conductivity under atmospheric pressure, P _1/2 : under vacuum (1 Pa or less) ) Is added and divided by 2, the atmospheric pressure value (atmospheric pressure value) at the time of the thermal conductivity) can be accepted. In this way, the values of the calibration results of the pressure sensor and the core material can be set in advance.

In the threshold value input field in the display screen shown in FIG. 5, the input of the manufacturing date of the vacuum heat insulating material can be accepted, and the input of the thermal conductivity and the durability inside the vacuum heat insulating material can be accepted as the threshold value. The terminal 40 can display a graph or the like on the display screen as a long-term performance prediction result and a determination of the predicted result of the heat insulation performance change calculated by the server 30. If the prediction result does not exceed the thermal conductivity and the number of years specified in advance as the threshold value, the judgment can be displayed as good (◯), and in addition, the replacement time (for example, after the third year) can be displayed.

FIG. 6 is a flowchart showing a flow of processing for converting an output value acquired from a pressure sensor in a small wireless vacuum gauge into a pressure value. The process is executed by the pressure gradient calculation unit 311 of the server 30. First, the measurement data measured by the pressure sensor 1 (see FIG. 2) acquired from the small wireless vacuum gauge 10 stored in the measurement data storage unit 381 of the server 30 is acquired (step S100). Next, the parameters of the core material are acquired (step S101). The parameters of the core material can be input to the user via the display screen shown in FIG. Finally, the parameters and measurement data of the core material are converted into pressure values (S102).

The conversion from the measurement data to the pressure value is, for example, various parameters of the pressure sensor 1 input by the user via the display screen shown in FIG. 5 (To: sensor output value at atmospheric pressure, Tmax: in a vacuum state). Converted by substituting the sensor output value, P _1/2 : pressure when the sensor output value is halved) into the theoretical formula y = Tmax / (1 + x / (P _1/2 ))-To. can do. In the theoretical calculation formula, x is the internal pressure (Pa), and y is the output value of the measurement data of the pressure sensor 1 of the small wireless vacuum gauge 10. FIG. 7 shows the results plotted in a graph with the x-axis as the internal pressure (Pa) and the y-axis as the output value of the pressure sensor 1 (microvacuum sensor output value).

Further, various parameters of the core material (λsr: thermal conductivity of dry air, λga: thermal conductivity under atmospheric pressure, P _1/2 : under vacuum) input by the user via the display screen shown in FIG. (1Pa or less), can be converted by substituting into the theoretical formula y = λsr + λga / (1+ (P _1/2 ) / x). X in the theoretical formula is the internal pressure (Pa). ), And y is the thermal conductivity (mW / mK) of the core material (glass wool) of the vacuum heat insulating material 20. The x-axis is the internal pressure (Pa) and the y-axis is the thermal conductivity of the core material. The results plotted in FIG. 8 are shown in FIG. 8. FIG. 9 is a graph showing the graphs shown in FIGS. 7 and 8 superimposed.

FIG. 10 is a flowchart showing a flow of processing for determining the heat insulating performance of the vacuum heat insulating material when the designated period has elapsed based on the thermal conductivity converted from the pressure gradient value. In step S110, the pressure gradient calculation unit 311 of the server 30 calculates ΔPa (internal pressure-past (initial) internal pressure / measurement days) from the data accumulated in the storage unit 38 (measurement data storage unit 381, internal pressure value storage unit 382). calculate. The calculation formula of ΔPa is based on the above-mentioned formula (1).

In step S111, the performance determination unit 312 of the server 30 calculates the long-term performance of the designated period based on the relational expression between the internal pressure and the thermal conductivity. Specifically, based on the above-mentioned mathematical formulas (2) to (4), the replacement timing of the vacuum heat insulating material and the thermal conductivity inside the vacuum heat insulating material are calculated. In step S112, the performance determination unit 312 determines whether or not the calculated result exceeds the thermal conductivity (designated thermal conductivity) specified by the user as a threshold value via the display screen shown in FIG. .. When the specified thermal conductivity is exceeded (“Yes” in S112), the notification unit 313 gives a notification prompting the replacement of the vacuum heat insulating material (S113), and when the specified thermal conductivity is not exceeded (“No” in S112), The notification unit 313 can display the predicted exchange time on the screen (output unit 47) of the terminal 40. The prediction of the replacement time of the vacuum heat insulating material can be determined, for example, based on the correlation coefficient between the current value and the past value of the pressure gradient value (the above-mentioned mathematical formulas (3) and (4)).

The vacuum heat insulating material equipped with the micro vacuum sensor was allowed to stand in the environment shown in the table below, and the long-term performance (time change of thermal conductivity) was measured and compared with the performance converted from the internal pressure.

Various parameters of the core material (λsr: Solid and radiant thermal conductivity of the core material when Pa, which is the atmospheric pressure, is 1 Pa or less, λga: Thermal conductivity under atmospheric pressure, P _1/2 : Under vacuum (1 Pa or less) The atmospheric pressure value at the time of the thermal conductivity obtained by adding the values of the thermal conductivity in) and dividing by 2) is as shown in the table below.

The thermal conductivity λ _cop (also referred to as “calculated thermal conductivity”) calculated based on the above-mentioned mathematical formula (2) was obtained, and the obtained value of the thermal conductivity λ _cop (current value) and the value obtained in the past were obtained. The correlation coefficient with the value (past value) was calculated based on the above-mentioned mathematical formula (4). The results are shown in the table below. On the 190th day, a hole was made in the vacuum heat insulating material with a needle hole, and the hole was closed with a curing tape, which intentionally caused a deterioration in performance.

FIG. 11 is a graph showing the relationship (pressure gradient) between the internal pressure of the vacuum heat insulating material and the period (days). Such a graph can be displayed on the display screen shown in FIG. 5 as a long-term performance prediction result. As can be seen from the graph shown in FIG. 11, the time change of the internal pressure basically increases at a constant rate. If the performance drops significantly, the correlation coefficient drops significantly as shown in the above table, so it is possible to issue an alert under the following conditions. (1) If the performance estimated from the results of the past four pressure measurements exceeds the performance (years and thermal conductivity) specified by the user, an alert is displayed. In addition, (2) if the correlation coefficient is less than 0.7 and it is estimated that there is a problem with product performance, an alert is displayed.

Regarding (1), a notification that "performance will reach 〇mW / mK in 〇 years" is displayed in the process of the product's performance change naturally, but when the performance change exceeds the user (customer) request. You can display alerts. On the other hand, if the performance changes suddenly as in (2), it is assumed that there is something wrong with the product, so this also issues an alert and gives an instruction to suggest replacement, and the insulation performance changes. It can be provided from the prediction system.

With the above configuration, the heat insulating performance change prediction system according to one embodiment of the present invention predicts the change in heat insulating performance several years after or after several years of the vacuum heat insulating material based on the calculated pressure gradient. Also, based on the predicted change in heat insulation performance, alerts regarding the replacement timing of the vacuum heat insulating material and the current heat insulation performance are given, and the person who monitors the long-term change in heat insulation performance of the vacuum heat insulating material (constructor). , Manufacturer, etc.).

The vacuum heat insulating material according to the present invention can be used for the outer wall of a house or a plant in order to efficiently utilize the thermal energy. In particular, it can be used for long-term operation and performance prediction of the vacuum heat insulating material by measuring the heat insulating performance after the construction of the vacuum heat insulating material.

1 Pressure sensor 2 Operational amplifier 3 A / D converter 4 CPU / wireless transmission unit 5 Temperature / humidity sensor / internal clock 6 Charging unit 7 DC / DC converter 8 Battery 10 Small wireless vacuum gauge 20 Vacuum insulation 30 Server 31 CPU
311 Pressure gradient calculation unit 312 Performance judgment unit 313 Notification unit 33 Memory 34 Bus 35 Input / output interface 36 Input unit 37 Output unit 38 Storage unit 381 Measurement data storage unit 382 Internal pressure value storage unit 39 Communication unit 40 Terminal 41 CPU
411 Browser program 43 Memory 44 Bus 45 Input / output interface 46 Input unit 47 Output unit 48 Storage unit 49 Communication unit N Network

Claims (11)

A small wireless vacuum provided inside the outer layer of the vacuum heat insulating material including the core material, the gas barrier film covering the core material, and the outer layer provided on the outside of the gas barrier film, and the inside of which is vacuum-sealed. A storage unit that stores measurement data acquired from a small radio pressure gauge including at least a pressure sensor and a transmission unit that transmits measurement data measured by the pressure sensor.
From the measurement data, the internal pressure value indicating the internal pressure of the vacuum heat insulating material at the time of measurement by the pressure sensor is obtained, and the internal pressure difference between the internal pressure value and the past internal pressure value representing the past internal pressure of the vacuum heat insulating material. And a pressure gradient calculation unit that acquires a pressure gradient value that represents the amount of change in the internal pressure difference per unit time.
A performance determination unit that determines the heat insulating performance of the vacuum heat insulating material when a predetermined designated period has elapsed based on the thermal conductivity converted from the pressure gradient value.
Including a notification unit that gives a notification according to the determination result by the performance determination unit.
The performance determination unit determines whether or not the thermal conductivity is equal to or higher than a predetermined thermal conductivity specified in advance.
The notification unit is a heat insulating performance change prediction system characterized in that when the performance determining unit determines that the thermal conductivity is equal to or higher than the designated thermal conductivity, a notification prompting the replacement of the vacuum heat insulating material is given. The heat insulation performance change prediction system according to claim 1, wherein the pressure gradient value is calculated by the following mathematical formula (1).

However, ΔPa is the pressure gradient value, Pa _c is the internal pressure value of the vacuum heat insulating material at the time of measurement, Pa _a is the past internal pressure value measured earlier than Pa _c , and Day. Is the number of days representing the measurement interval from the time of measurement of Pa _{a to} the time of measurement of Pa _c . The heat insulating performance change prediction system according to claim 2, wherein the thermal conductivity is calculated by the following mathematical formula (2).

However, λ _cop is the thermal conductivity of the central part of the vacuum heat insulating material, λ _sr is the solid and radiated thermal conductivity of the core material, λ _ga is the thermal conductivity of dry air, and P _1/2 is The value of the thermal conductivity of the core material under atmospheric pressure and the value of the thermal conductivity under vacuum (1 Pa or less) are added and divided by 2, the atmospheric pressure value at the time of thermal conductivity, t is the replacement time. It is a value representing. The heat insulation performance change prediction system according to claim 3, wherein the value t representing the replacement time is a value for the designated period designated in advance. The heat insulation performance change prediction system according to claim 2, wherein the replacement time is calculated by the following mathematical formula (3).

However, t is a value _indicating the replacement time, λ _cop is the thermal conductivity of the central part of the vacuum heat insulating material, λ _sr is the solid and radiated thermal conductivity of the core material, and λ _ga is the dry air. It is the thermal conductivity, and P _1/2 is the value of the thermal conductivity of the core material under atmospheric pressure and the value of the thermal conductivity under vacuum (1 Pa or less) added and divided by 2. It is the atmospheric pressure value at the time. The adiabatic performance change prediction system according to claim 5, wherein the λ _cop is a value of the designated thermal conductivity specified in advance. The heat insulating performance according to any one of claims 1 to 6, wherein the notification unit notifies the period or time until the thermal conductivity of the vacuum heat insulating material reaches the designated thermal conductivity. Change prediction system. The notification unit is characterized in that, when the performance determination unit determines that the thermal conductivity is less than the designated thermal conductivity, the notification unit notifies the period or time until the designated thermal conductivity is reached. Item 7. The heat insulating performance change prediction system according to Item 7. Further, in the performance determination unit, the correlation coefficient between the current value of the thermal conductivity λ _cop and one or more past values acquired in the past by the performance determination unit is equal to or greater than the specified correlation coefficient specified in advance. Judge whether or not
The notification unit is characterized in that when the performance determination unit determines that the correlation coefficient is less than the designated correlation coefficient, it notifies a notification prompting the replacement of the vacuum heat insulating material or a warning notifying an abnormality. The heat insulating performance change prediction system according to any one of claims 1 to 8. The change in heat insulating performance according to claim 9, wherein the correlation coefficient is calculated by the following mathematical formula (4), where the current value of the thermal conductivity λ _cop is X and the past value is Y. Prediction system.

A heat insulation performance change prediction program, characterized in that the computer functions as the heat insulation performance change prediction system according to claims 1 to 10.

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