EP0153953A1

EP0153953A1 - An arrangement and a method for using the arrangement for cooling, energy storage and fire retardation

Info

Publication number: EP0153953A1
Application number: EP19840903377
Authority: EP
Inventors: Rolf Ulfvengren
Original assignee: CLIMATOR AB
Current assignee: CLIMATOR AB
Priority date: 1983-09-07
Filing date: 1984-09-07
Publication date: 1985-09-11
Also published as: SE8304789D0; SE8304789L; WO1985001079A1

Abstract

Montage pour construire des bâtiments, des coffres-forts pour des objets de valeur et de l'argent et des coffrets pour ordinateurs ou tableaux commutateurs de téléphone. Le montage est une unité formée d'une couche extérieure, d'un matériau thermiquement isolant et d'un matériau de stockage d'énergie constituant un système convertisseur de phase. La figure 2 montre comment placer les couches extérieures (4) et le matériau isolant associé (11) de manière à former deux intervalles d'air (5). Un milieu calorifère comme l'air peut être conduit à travers ces derniers afin de refroidir ou de chauffer l'air tout en utilisant les caractéristiques de stockage d'énergie du matériau convertisseur de phase (6).Assembly for constructing buildings, safes for valuables and money and boxes for computers or telephone switchboards. The assembly is a unit formed by an outer layer, a thermally insulating material and an energy storage material constituting a phase converter system. Figure 2 shows how to place the outer layers (4) and the associated insulating material (11) so as to form two air gaps (5). A heat-generating medium such as air can be passed through them to cool or heat the air while using the energy storage characteristics of the phase converter material (6).

Description

An arrangement and a method for using the arrangement for cooling, energy storage and fire retardation

It is known that in recent years increasing interest has attached to different methods for reducing the costs of heating premises. During the half year of winter much energy is consumed for heating premises while during the other part of the year energy is used for cooling. In this context the term energy relates principally to electrical energy.

The construction materials forming part of a building may have to satisfy various requirements. E.g. in respect of load-bearing capacity, aesthetic impression, thermal inertia (thermal capacity) and incombustibility. The latter must not be overlooked since inter alia property insurance rates depend on the fire characteristics of the building materials. The lower a material's tendency to burn, the lower are the rates.

One method which is frequently used in order to achieve the above storage and fire retardation characteristics and in part cooling characteristics consists in making use of concrete units. One has for instance developed concrete units with ducts in which a heatcarrying medium, generally air, is allowed to circulate, both for heating and cooling. The material is after all entirely inorganic and in addition satisfies the requirement of incombustibility.

One of the disadvantages of this construction method consists in the fact that it is difficult to make the material sufficiently insulating. I.e. impart to the construction a low "k-value" (heat transmission coefficient). A material which imparts a low k-value to a construction is e.g. mineral wool. However with this material there is the disadvantage of low thermal capacity.

Numerous solutions for this problem have been advanced. Inter alia in the Swedish patent application 7901433-8. This application specifies the use of Glauber's salt in plates located within the inner roof in order to act as heat stores in conjunction with e.g. woodburning stoves. A phase converting material can also be used in order to impart thermal inertia to light building constructions. This is well known and there exist numerous patents and patent applications proposing different methods for utilising this physical characteristic of certain materials.

Perhaps the most common phase converting material, or at least the one which is most widely used, is Glauber's salt (sodium sulphate decahydrate). It has however proved that this salt cannot be used in relatively large containers since during phase conversion the material is subject to stratification as a result of which the material becomes irreversible, i.e. the heat storage capacity declines until it ceases entirely (cf. e.g. the technical report 1981 :05 of the national Swedish Institute for Materials Testing (Statens Provningsanstalt)).

Now it is as such known to make use of a phase converting material in building units. For instance, the British patent 1 298674 shows several methods of producing such units. It covers a number of different practical solutions for energy stores. In the above British application it is also shown how the said stratification can be avoided by encapsulating the phase converting material in a number of capsules.

Unfortunately it has not been possible to produce functional construction units containing phase converting material but there are always independent energy stores in the shape of containers with the material fitted more or less efficiently.

The present invention proposes an arrangement by means of which a considerable number of practical problems associated with building constructions can be solved. The invention is not restricted only to constructions for buildings but can also be used for document safes, money safes and also boxes for accommodating electronic equipment such as computers and telephone switchboards.

The invention consists in a sandwich unit with, from one side, an outer layer of preferably incombustible material. This is followed by an insulating material, which may be mineral wool. The next layer consists in a surface material and one then allows an air gap to form before installing the phase converting material after a further layer of outer material. Thereafter the design is the same as hitherto but in reverse sequence. As regards the material symmetry may accordingly be said to exist. But it is of course also possible to consider other sequences of material combinations. If an arrangement according to the invention is used it can be utilised for cooling, energy storage and fire retardation. With a view to describing the invention in greater detail reference is made to three figures. Figure 1 relates to a test described below. Figure 2 is a cross-section of an arrangement or unit. This figure should be regarded as one of many feasible embodiments. Finally figure 3 illustrates a test arrangement. This arrangement is related to figure 1 .

In figure 2 we have a cross-section of a unit. The outer layer (4) may be such as to combine good strength and incombustibility characteristics with an aesthetically appealing pattern. Two air gaps (5) are then formed by installing the container of phase converting material (6), preferably Glauber's salt, at the centre. With units for vertical placing this consists of a number of small spaces produced with the aid of e.g. folded material (similar to corrugated cardboard) glued to the outer layer. Another way of achieving this result consists in the use of "honeycomb structures". The unit shown in figure 2 offers the advantage of ensuring on the one hand good heat insulation thanks to the insulating material (11). The latter can also be so selected as to achieve good sound absorption within the high frequency band. In the air gaps (5) room air can be conducted in order to cool it (if the phase converting material is in frozen form) or heat it (if the phase converting material is in molten form). In addition, this layer, the weight per unit area of which is high by comparison with the other materials, acts as a sound damping material at low frequencies.

When experimenting with this type of unit the surprisingly good fire inhibiting characteristic has been found surprising. This shall be illustrated by the following example. In figure 3 is a test arrangement of simple design. It consists of a walled furnace containing a number of Kanthal elements capable of raising the temperature in the furnace to 1000 degrees C in accordance with the standard curve used in fire tests. The supply of energy to these Kanthal elements is controlled by measuring devices fitted within the furnace, which are connected to a regulator ensuring that the temperature develops in accordance with the "fire curve". The regulator, the Kanthal elements and the measuring device are not shown in the figure. In the figure the walls (10) are masonry walls and the test material (unit) (6) is placed on the furnace by way of an upper boundary. The inside of the furnace (7) is thus heated to a temperature of 1000 degrees C. A measuring device (9) in the form of a thermoelement is located on the unit (8). The signal of this thermoelement and the temperature in the furnace can be recorded.

In figure 1 the result of a test is shown. The vertical coordinate shows the temperature and the horizontal coordinate the time. The curve marked (l) is the "fire curve". Curve (2) corresponds to the furnace temperature during the experiment.

At closer inspection we find a certain anomaly in this curve. (2). The curve does not manage to follow the standard curve, in spite of the regulator. This is due to the fact that the energy absorption capacity of the phase converting material is in terms of power higher than the output of the Kanthal elements. But it is interesting to note that curve (3) shows a highly fire retardant effect. For a temperature of 100 degrees to be exceeded takes over 45 minutes. This was the case in spite of the fact that the unit tested consisted only of phase converting material within a plate. If the unit had consisted only of plate material, curve (2) would have followed curve (1) without time lags.

The above text has dealt with the units. Below the unit is described in somewhat greater detail. This description refers to other known methods of constructing units. Therefore no additional figure has been produced in this connection.

The unit is produced with basically at least one outer layer and one type of filling material. The filling material may, for instance, have decorative, load-bearing and fire retardant characteristics. The filling material often has insulating characteristics. A material with this structureis for instance the TNF unit from Eockwool AB. If the filling material fills the inner space completely, a durable product may be achieved in combination with the outer layer, such a product being normally described as a composite. Such composites consist for instance of an outer epoxy layer reinforced with carbon fibre and a filling material such as polyurethane. Such units are easy to produce since they need only be glued together. With the unit described in connection with the present invention an air gap is also provided. This makes the production of the unit somewhat more complicated. One can imagine two basic methods which as such are also capable of being combined.

As the simplest unit to be produced must be regarded a unit with a framework which retains the various component materials in a predetermined position. One disadvantage of this type of unit consists in the fact that it cannot be made in very large areas or for very large spans.

With the other main method of joining units such as described in the present invention spacers are distributed over the surface of the unit. This method is subject to the disadvantage that e.g. the spacing devices may act as cold transmitting elements. This can be avoided by making these spacing devices of less thermally conductive material. The spacing devices are secured between the various materials forming part of the unit, including the outer layers, by gluing, welding or some other suitable method.

Such units can be easily produced by a manufacturing process as such readily automated. Such a process may for instance comprise glue coating machines and curing chambers for the glue applied. Good glues are for instance phenolic or resorcinol glues.

Claims

PATENT CLAIMS

1. An arrangement for constructing walls, roofs and floors, characterised in that the arrangement consists of a unit composed of the following components: Outer layer, insulating material and phase converting material. Using fixing devices the materials are so placed in relation to one another that the outer layer constitutes outer boundaries of the arrangement on its two exterior sides. The insulating material is located on the insides of these outer layers, and the phase converting material enclosed in a second outer layer is so located that gaps are formed between the phase converting material and the insulating material with a view to conducting within these gaps a gaseous thermal medium, preferably air.

2. A method for using the arrangement in accordance with patent claim 1, characterised in that buildings, document safes, money safes or boxes for accommodating operational computers or telephone switchboards are constructed of the arrangement, so as to be able to cool, store heat, insulate and serve as a fire-retardant with fire coming from outside by making use of the physical characteristics possessed by the materials forming part of the unit.

3. An arrangement in accordance with patent claim 1, characterised in that the outer layer forming part of the unit consists of incombustible material.

4« An arrangement in accordance with patent claim 1, characterised in that the insulating material consists of mineral wool.

5. An arrangement in accordance with patent claim 1, characterised in that the phase converting material forming part of the arrangement is Glauber's salt, which with a view to avoiding stratification is blended with a thickening agent and/or encapsulated in a container with a maximum vertical dimension of between 10 and 20 mm. AMENDED CLAIMS

[received by the International Bureau on 21 January 1985 (21.01.85); original claims 1-5 replaced by new claims 1-3 (1 page)]

1. An arrangement for providing boundary faces for storage spacei for temperature-sensitive material and for providing boundary faces for storage spaces with improved fire resistance characterised in that the arrangement consists of a unit composed of the components outer layer (4). insulating layer (11) and phase converting material (6). The outer layer is incombustible, the insulating material consists of mineral fibres end the phase converting material is of the type Glauber's salt.

2. A method for using the arrangement in accordance with patent claim 1 characterised in that boxes for storing temperature-sensitive material are constructed of the arrangement, which in case of a fire outside the box exhibit improved resistance against fire so that from the start of the fire the temperature inside the box does not increase by more than 50 degrees C. 3. An arrangement in accordance with patent claim 1 characterised in that the Glauber's salt is blended with a thickening agent in order to prevent stratification or in that the salt is, to the same end, stored in cellular structures, the maximum dimension within the cell being 20 mm.