TRANSPORT CONTAINER FOR TRANSPORTING TEMPERATURE-SENSITIVE GOODS

Description

[0001] The invention relates to a transport container for transporting temperature-sensitive goods, comprising an interior space for receiving the goods to be transported and a shell enclosing the interior space, which shell comprises thermal insulation, wherein at least one latent heat accumulator and at least one active temperature control element are provided in order to temperature-control the interior space.

[0002] When transporting temperature-sensitive goods, such as pharmaceuticals, over periods of several hours or days, specified temperature ranges must be maintained during storage and transport to ensure the usability and safety of the medicinal product. For various medicinal products, temperature ranges of 2 to 25°C, particularly 2 to 8°C, are specified as storage and transport conditions.

[0003] The desired temperature range can be above or below the ambient temperature, requiring either cooling or heating of the interior of the transport container. If ambient conditions change during transport, the required temperature control may include both cooling and heating. To ensure that the desired temperature range is permanently and verifiably maintained during transport, transport containers with special insulation properties are used. These containers are equipped with passive or active temperature control elements. Passive temperature control elements do not require an external energy supply during use, but utilize their heat storage capacity, whereby, depending on the temperature level, heat is released or absorbed into or from the interior of the transport container to be temperature-controlled.However, such passive temperature control elements are exhausted as soon as the temperature equalization with the transport container interior is completed.

[0004] A special form of passive temperature control elements are latent heat storage devices, which can store thermal energy in phase-change materials whose latent heat of fusion, solution, or absorption is significantly greater than the heat they can store based on their normal specific heat capacity. The disadvantage of latent heat storage devices is that they lose their effectiveness once the entire material has completely undergone the phase change. However, by performing the opposite phase change, the latent heat storage device can be recharged.

[0005] Active temperature control elements require an external power supply to operate. They are based on the conversion of a non-thermal form of energy into a thermal form of energy. The release or absorption of heat occurs, for example, within the framework of a thermodynamic cycle, such as a compression refrigeration machine. Another type of active temperature control element operates on the thermoelectric principle, using so-called Peltier elements.

[0006] Transport containers have already been described in which active and passive temperature control elements are combined in such a way that the active temperature control elements are used to recharge the latent heat storage devices when needed. US 2015 / 166262 A1 describes a transport container which has latent heat storage devices acting as cooling elements and latent heat storage devices acting as heating elements in a container area separate from the space for the transported goods. A fan generates air circulation, with air being directed either over the surface of the latent heat storage devices acting as cooling elements or over the surface of the latent heat storage devices acting as heating elements, and the thus tempered air is transported into the space for the transported goods. Lines run through the latent heat storage elements, through which actively cooled or heated medium can flow in order to recharge the latent heat storage devices.The lines are part of a compression refrigeration machine, the components of which can be arranged in a separate area of ​​the transport container.

[0007] In the subject matter of US 2004 / 226309 A1, air cooled by heat exchange with a compression refrigeration machine is directed into the receiving space for the transported goods to cool the transported goods there. The cooled air can also be blown over the surfaces of a latent heat storage device to charge it, thus ensuring the temperature control of the transported goods even after the active temperature control system is switched off.

[0008] WO 2004 / 080845 A1 also describes a transport container with active and passive temperature control elements. The primary cooling is achieved by a compression refrigeration unit. A latent heat storage unit is provided as a backup system, which can be charged by heat exchange with the compression refrigeration unit. In passive backup mode, air is blown over the surfaces of the latent heat storage unit to use the tempered air to temper the transported goods.

[0009] US 9 038 412 B2 discloses a refrigerated container designed to hold ice for cooling food. To charge the cooling element for a sales cycle, the refrigerated container has a cooling element into which evaporator lines of a refrigeration unit are embedded for cooling the cooling element. The cooling element is further surrounded by insulation, on the outside of which a condenser coil of the refrigeration unit is arranged.

[0010] A disadvantage of the described systems is that the active and / or passive temperature control elements are located in a separate, usually isolated, area of ​​the container, requiring air circulation to transfer heat between the compartment for the transported goods and the temperature control elements. Fans are required to generate the necessary air circulation, which consumes electrical energy, so appropriate storage capacity must be provided and transported along with the container.

[0011] Furthermore, it must be considered that the energy input into the transport container during transport is heterogeneous. If the container is exposed to thermal radiation, the energy input in the area exposed to radiation is significantly greater than in the areas where no radiation affects the container. Nevertheless, the temperature inside the container must be kept constant and homogeneous within a permissible range. With inhomogeneous energy input, the problem arises that the latent heat storage is not used up homogeneously. Thus, after a certain period of time, local temperature changes occur inside the transport container. If the local temperature changes exceed or fall below a certain threshold, the transported goods are no longer protected.

[0012] The invention therefore aims to overcome the aforementioned disadvantages and to improve a transport container by reducing power consumption, creating a compact and simple design, and reducing the susceptibility to errors. Furthermore, local temperature differences within the interior of the transport container are to be avoided as much as possible.

[0013] To achieve this object, the invention essentially provides for a transport container of the type mentioned at the outset to have a multi-layered shell, with the thermal insulation, the latent heat accumulator and the active temperature control element being designed as separate, superimposed layers of the shell. The layered structure according to the invention allows the latent heat accumulator and the active temperature control to be integrated directly into the wall elements delimiting the interior, with the individual layers being in contact with the interior by thermal conduction in order to temperature-control this interior along with the transported goods contained therein. Heat transfer by convection, i.e. by actively circulating air, is therefore not required, so that the fans and the like required for this can be dispensed with. This can reduce power consumption and susceptibility to errors.Furthermore, the provision of a separate area of ​​the container for the installation of refrigeration units and the like can be dispensed with. According to the invention, the insulation layer is arranged between the more externally located active temperature control layer and the more internally located latent heat storage layer. This design with an externally located active temperature control layer offers particular advantages when the active temperature control layer comprises Peltier elements, since these require a strong external energy output.

[0014] The integration of the latent heat storage and the active temperature control element into the layers of the walls defining the interior further facilitates the construction of the container. The multi-layer walls can be provided as prefabricated modules, enabling modular assembly of transport containers.

[0015] A further advantage of the inventive design lies in the uniform heat input into the interior and the large surface area available for heat transfer. In this context, a preferred embodiment provides for the latent heat storage layer, the insulation layer, and the active temperature control layer to each completely enclose the interior.

[0016] The layer equipped with the active temperature control element, i.e., the temperature control layer, can be used to charge the latent heat storage layer as needed. Alternatively or additionally, the latent heat storage layer can also be used to directly control the temperature of the container's interior.

[0017] Within the scope of the invention, it is not mandatory that the three layers—i.e., the insulation layer, the latent heat storage layer, and the active temperature control layer—be arranged directly on top of one another. Two layers can also be connected to each other with an additional layer interposed. The additional layer can be an adhesive layer used to bond the two layers together, or a functional layer.

[0018] Furthermore, the invention is not limited to the layered structure of the shell comprising only a single latent heat storage layer, insulation layer, and active temperature control layer. Rather, designs in which two or more latent heat storage layers, two or more insulation layers, and / or two or more active temperature control layers are provided are also conceivable.

[0019] A preferred embodiment provides that at least two of the three layers (latent heat storage layer, insulation layer, tempering layer), in particular all three layers lying one above the other, are in thermally conductive connection with one another, in particular in full-surface contact with one another.

[0020] In a particularly simple manner, the transport container is cuboid-shaped, and the shell consists of six walls, each of which has at least three layers and comprises a latent heat storage layer, an insulation layer, and an active temperature control layer. One of the six walls can be designed as a door.

[0021] The transport container according to the invention can be designed as a standardized ISO container (20 or 40 feet) or as an air freight container, in particular as a standardized "Unit Load Device", wherein the container walls, ie the outer walls of the container, have the layer structure according to the invention.

[0022] The active temperature control layer is preferably one for converting electrical energy into heat for release or absorption. To supply the required electrical energy, the transport container is preferably equipped on its exterior with connecting means, in particular a socket, for electrically connecting to an external power source. As soon as an external power source is available, the active temperature control layer can thus be put into operation.

[0023] Furthermore, the transport container can be provided with an electrical energy storage device, such as a rechargeable battery, which can be powered by an external power source. The electrical energy storage device can be arranged to supply the control and, if applicable, temperature monitoring electronics of the transport container with electrical energy. Furthermore, the electrical energy storage device can be connected to the active temperature control layer in order to supply it with electrical energy as needed. This enables at least short-term operation of the active temperature control layer even during transport when no external power source is available.

[0024] A preferred embodiment provides for the active temperature control layer to have Peltier elements, a heat exchanger interacting with a thermodynamic cycle, in particular a compression refrigeration machine, or a magnetic cooling system. Peltier elements are particularly preferred because they can be made small and easily integrated into the temperature control layer. The temperature control layer preferably comprises a plurality of Peltier elements, the cold and warm sides of which are each connected to a common plate-shaped heat-conducting element. The plate-shaped heat-conducting elements thus form the top and bottom sides of the temperature control layer and support Peltier elements arranged between them.

[0025] As an additional measure to avoid the negative effects of heterogeneous external energy, it can preferably be provided that an energy distribution layer made of a highly thermally conductive material is arranged within the energy distribution layer for the uniform distribution of thermal energy acting on the container from the outside, wherein the energy distribution layer is preferably arranged further outward than the latent heat storage layer. The energy distribution layer preferably has a thermal conductivity of l > 100 W / (mK), preferably l > 200 W / (mK).

[0026] To achieve homogenization of the temperature prevailing in the interior of the transport container, an energy distribution layer can alternatively or additionally be arranged on the side of the latent heat storage layer facing the interior. The energy distribution layer preferably has a thermal conductivity of l > 100 W / (mK), preferably l> 200 W / (mK).

[0027] To promote the most even energy distribution possible in the interior, the innermost layer of the container wall is preferably designed with a high emissivity and / or high thermal conductivity. Regarding thermal conductivity, the innermost layer can be designed as an energy distribution layer as mentioned above (thermal conductivity of l > 100 W / (mK), preferably l> 200 W / (mK)). The innermost layer is the layer that is in direct contact with the interior or that borders it. In order to ensure that the energy is removed from the interior or supplied to the interior to a sufficient extent so that, for example, transport goods that are too warm can be cooled down without convection or the entire interior can be used for the transport goods, the quality of the innermost layer is crucial. This can be treated in such a way that thermal radiation is increased, whereby achieving an emissivity of > 0.1, preferably between 0.5 and 1, is preferred. The emissivity can be increased by treating the surface, e.g. in the case of metals by grinding or painting, or in the case of aluminum by chromating. Alternatively or additionally, the heat transfer between the innermost layer and the transport goods orThe air quality of the indoor air can be increased by increasing the surface area through structures such as waves with a radius of at least 5mm. Ideally, the surface area should be increased by at least 30%.

[0028] The latent heat storage layer is preferably designed as a flat chemical latent heat storage device, with conventional designs being usable with regard to the medium forming the latent heat storage device. Preferred media for the latent heat storage devices are paraffins and salt mixtures. The phase transition of the medium is preferably in the temperature range of 0-10°C or between 2-25°C.

[0029] The insulating layer is preferably designed as vacuum insulation. The insulating layer preferably comprises at least one evacuated cavity. Alternatively, the at least one cavity can be filled with a gas that is a poor thermal conductor. Furthermore, the insulating layer can have a honeycomb structure. An advantageous embodiment results when the insulating layer has a plurality of hollow chambers, in particular honeycomb-shaped ones, with a honeycomb structure element according to WO 2011 / 032299 A1 being particularly advantageous.

[0030] The invention is explained in more detail below using an embodiment shown schematically in the drawing.

[0031] In Fig. 1A cuboid-shaped transport container 1 is shown, the walls of which are labeled 2, 3, 4, 5, and 6. The sixth side of the transport container 1 is shown open so that the layered structure of the walls is visible. The open side can be closed, for example, by means of a door that has the same layered structure as walls 2, 3, 4, 5, and 6. The six walls of the transport container 1 all have the same layered structure. The layered structure comprises an outer layer 7, a middle layer 8, and an inner layer 9.

[0032] According to the invention, layer 7 is an active temperature control element, such as a layer provided with Peltier elements, layer 8 is an insulating layer and layer 9 is a latent heat storage layer.

Claims

1. Transport container for transporting temperature-sensitive goods to be transported, comprising an interior space for receiving the goods to be transported and a shell which encloses the interior space and comprises a thermal insulation, at least one latent heat storage and at least one active temperature control element being provided in order to control the temperature of the interior space, the shell being of multilayer design, wherein the thermal insulation, the latent heat storage and the active temperature control element are formed as layers (7, 8, 9) of the shell which are separate from one another and superimposed, and the insulating layer (8) is arranged between the active temperature control layer (7) lying further outward and the latent heat storage layer (9) lying further inward.

2. Transport container according to claim 1, characterised in that at least two, in particular all three, superimposed layers (7, 8, 9) are in thermally conductive contact with one another, in particular in full-surface contact with one another.

3. Transport container according to claim 1 or 2, characterised in that the latent heat storage layer (9), the insulating layer (8) and the active temperature control layer (7) each completely enclose the interior.

4. Transport container according to claim 1, 2 or 3, characterised in that the transport container (1) is cuboidal and the shell consists of six walls (2, 3, 4, 5, 6), of which each wall (2, 3, 4, 5, 6) is formed in at least three layers and comprises a latent heat storage layer (9), an insulating layer (8) and an active temperature control layer (7).

5. Transport container according to claim 4, characterised in that one of the six walls (2, 3, 4, 5, 6) is designed as a door.

6. Transport container according to one of claims 1 to 5, characterised in that the active temperature control layer (7) is designed to convert electrical energy into heat to be emitted or absorbed.

7. Transport container according to one of claims 1 to 6, characterised in that the active temperature control layer (7) comprises Peltier elements, a heat exchanger interacting with a thermodynamic cycle, in particular a compression refrigeration machine, or a magnetic cooling system.

8. Transport container according to one of claims 1 to 7, characterised in that, furthermore, an energy distribution layer made of a highly thermally conductive material for the uniform distribution of thermal energy acting externally on the container is arranged within the energy distribution layer, the energy distribution layer preferably being arranged further ward than the latent heat storage layer (9).

9. Transport container according to claim 8, characterised in that a further energy distribution layer is provided, one energy distribution layer being arranged on each side of the latent heat storage layer (9).