DE102005051570A1 - Device for stabilising temperature inside containers and switch cabinets uses phase change material whose phase change temperature is within permissible range to fill hermetically sealed cavity between inside and outside walls of container - Google Patents

Abstract

Containers are designed with double walls on all sides so that the cavity between same is hermetically sealed and filled with a phase change material such as paraffin or paraffin mixtures whose phase change temperature is within the permissible temperature range inside the container . Phase change temperature is set so that at a given heat output inside the container and a given heat transmission resistance in the phase change material below the phase change temperature the sum of the phase change temperature and resulting temperature increase does not exceed the permissible upper limit of the temperature inside the container.

Description

The The present invention relates to the field of containers, control cabinets and other containers, in hereinafter generally referred to as a container, the outdoor use the daily routine of the outside temperature are exposed. In particular, but not exclusively this container, which is a heat source in the Inside, for example an electronic device, and thereby have a temperature increase in the interior compared to the outside temperature and the resulting daily temperature course in the interior of the container the permissible Exceed temperature range would, why a temperature stabilization must take place, the Daily cycle of the temperature in the interior of the container to the permissible temperature range limited.

State of the art

easiest Guard is a canopy of the container for protection against direct sunlight, as direct Insolation to uncontrolled heaters regardless of lead the air temperature can. Optionally, a lateral glare shield is used, to prevent radiation from reflective objects. Without additional Facilities results in the closed container from the heat output inside the container and the heat transfer resistance and size of the surface of the Containers a temperature increase in the Inside of the container opposite the outside temperature.

• – an der oberen Grenze der Außentemperatur ihren Maximalwert erreicht, weil der Wärmeübergangswiderstand infolge geringer Konvektion, zum Beispiel bei Windstille, hoch ist, beziehungsweise
• – an der unteren Grenze der Außentemperatur ihren Minimalwert erreicht, weil der Wärmeübergangswiderstand infolge intensiver Konvektion, zum Beispiel bei starkem Wind, niedrig ist.

Said temperature elevation is not constant and the critical cases are when they

• - At the upper limit of the outside temperature reaches its maximum value, because the heat transfer resistance due to low convection, for example, in calm, is high, or
• - At the lower limit of the outside temperature reaches its minimum value, because the heat transfer resistance due to intense convection, for example, in strong winds, is low.

• – der Wärmeübergangswiderstand des Containers durch Vergrößerung der Oberfläche verringert werden, wenn der kritische Betriebsbereich die Obergrenze der Außentemperatur ist, bzw.
• – der Wärmeübergangswiderstand des Containers durch Minimierung der Oberfläche erhöht werden, wenn der kritische Betriebsbereich die untere Grenze der Außentemperatur ist.

Depending on the conditions of use

• - The heat transfer resistance of the container can be reduced by increasing the surface, if the critical operating range is the upper limit of the outside temperature, or
• - The heat transfer resistance of the container can be increased by minimizing the surface, when the critical operating range is the lower limit of the outside temperature.

These trivial arrangements will be independent of any additional ones Facilities always applied. In other device is additionally an Convection through the housing allows. This measure lowers the temperature increase in the Inside of the container opposite the outside temperature in comparison to the closed container. This is at the top Limit of the outside temperature desirable, can at the lower limit of the outside temperature however, be counterproductive. In the majority of cases are in outdoor use however, openings in containers that allow effective convection, not feasible.

at In addition to other facilities is also the heat transfer resistance the container walls by thermal insulation and so that the resulting inside the container temperature increase increases. These measure is applicable if the upper limit of the outside temperature is sufficiently lower as the allowed Temperature inside the container is. The aforementioned passive Devices for temperature stabilization are in their effect very limited and in many cases Active equipment for temperature stabilization is used. Simple active facilities work with heat exchangers and two connected cycles as air / water or as air / air systems. In [1], pages 105/106 and pages 105/118, such devices presented. Inside the container there is a forced circulation, at which the heated Air through a heat exchanger to be led and there their warmth emits. The medium in the outer circle takes over the heat from the heat exchanger and leads this to the outside from. As a rule, the inner circle is closed and the outer circle, if air-based, open. Advantages are the simple principle and the low investment and installation costs. adversely are the high operating costs due to the energy requirements for the operation of the circuits and that the Internal temperature always a few, despite the use of the device Degrees above the medium in the outer circle lies.

Also in [1], pages 158/159, a device is described as a geothermal heat exchanger, which uses the constant temperature in deeper layers of the soil for the stabilization of the temperature in containers. A hose with a diameter of about 125mm and variable length (depending on the installed heat output) is laid in 3m depth in the ground as a loop. The ends of the hose end in the container. Through a fan, the air is forced out of the container through the hose, where the Air equalizes its temperature to that of the soil layer. With a heat output of 250W approx. 30m hose is needed. Advantages of the system are low energy and maintenance requirements and thus low operating costs. The applications are limited to the effect that the container must be placed on the ground or close to the ground and the substrate must allow the introduction of the hose with reasonable effort

Far The air conditioning of containers is widespread with the help of air conditioners. The Operating principle and technology correspond to the refrigerator. An additional ventilation system rolls the Air in the container around, distributes the cooled air and leads the heated Air in the heat exchanger of the air conditioner. The waste heat gets to the outside air issued. Advantages of these facilities are that they too can be used if there are high demands on the temperature stability or high heat outputs dissipate are.

• – für den Transport von Energie
• – für die Zwischenspeicherung von Energie
• – für die Aufbewahrung bzw. Transport von Gütern bei konstanter Temperatur
• – für die Wärmeisolation

Disadvantages of these devices are high energy requirements and thus high operating costs and a large space requirement. These disadvantages are exacerbated by the low efficiency, due to the operating conditions deviating from the refrigerator. In this only the low heat output is dissipate, which penetrates over the well-insulated walls. In the present case, from a certain outside temperature, a comparatively high heat output, which is constantly generated inside the container, dissipate. If the outside temperature exceeds the inside temperature, then the non-negligible heat output must be dissipated, which penetrates over the less thermally insulated walls of the container. Good thermal insulation would be counterproductive in the present case, as it would inhibit natural heat drainage at low outdoor temperatures, thus causing the air conditioning unit to operate over a wider range of outdoor temperatures. The inventively provided use of latent heat storage on the basis of so-called PCM (Phase Change Material) for the realization of the task (see below) is not common practice. Latent heat storage devices are used because they can absorb or release a large amount of energy per volume or unit of quantity during the phase change. Their use is so far

• - for the transport of energy
• - for the intermediate storage of energy
• - for the storage or transport of goods at constant temperature
• - for thermal insulation

Of the trivial case of transportation of energy is the cooling or filling with a PCM Heat pad, that for therapeutic Purposes is used. As PCM are mostly hydrate salts or organic PCM, which is also below the phase change temperature not get stuck, but at least keep a pulpy consistency.

Latent heat storage for the Caching of energy is used when energy is needed and energy needs in terms of time or size correlate or the energy supply at certain times of the day is cheaper and the more expensive time of day is bridged by stored energy should.

In [2] will have a solar system for described the hot water, in which a latent heat storage a temporary oversupply of solar energy.

In [3] and [4] will be applications for described the air conditioners of vehicles, in which in one first phase a latent heat storage excess cooling capacity an unregulated cooling unit absorbs and at the same time the cooling air flow stabilized to the phase change temperature. Once the energy storage capacity of the latent heat storage exhausted is in a second phase, the cooling unit is turned off and the cooling air flow when flowing through the latent heat storage cooled to the phase change temperature. In the change of both phases is achieved that the cooling unit intermittently operated only as needed.

In [5] describes an electric heating system in which a latent heat storage is heated with cheap night electricity and the stored energy for bridging during the more expensive time of day is used.

Latent heat storage can for the temporary storage or transport of goods be used at constant temperature.

• – zum Schutz gegen Abkühlung das PCM vorher vollständig über die Phasenwechseltemperatur erwärmt wurde, beziehungsweise
• – zum Schutz gegen Erwärmung das PCM vorher vollständig unter die Phasenwechseltemperatur abgekühlt wurde.

In [6] a double-walled container is described in which the double wall by Einbrin tion of a PCM is designed as a latent heat storage. The interior of the container is stabilized to the phase change temperature when

• - To protect against cooling the PCM was previously completely heated above the phase change temperature, respectively
• - To protect against warming the PCM was previously completely cooled below the phase change temperature.

In [7] describes a container whose walls are used as vacuum insulation panels accomplished are and which has a high thermal insulation due to this. Inside the Containers are latent heat storage in the form of plate-shaped containers attached, which the internal temperature depending on the application against over- or Stabilize below the phase change temperature, as long as the heat flow through the container wall, the storage capacity of the latent heat storage not exceeded Has.

For thermal insulation, latent heat accumulators are used in heat-insulating textiles and in heat-insulating components. For example, heat-insulating textiles are described in [8] and [9]. In 10] DE19929861 the production of heat-insulating components is described. Porous building blocks or granules are impregnated with PCM, preferably with paraffins, and protected against leakage of the PCM by means of special enclosures and used in this form directly for building or as a building aggregate. In [11] DE10019931 a heat-insulating device in the form of a Hypokaustenelementes is described, which also works with paraffin as PCM. Used as a wall element and flowed through by the air, it can absorb heat from the air flowing through it by heat exchange with the PCM or give it to this.

• – eine hohe spezifische Phasenwechselenergie,
• – günstige Möglichkeiten, die Phasenwechseltemperatur in weiten Grenzen einzustellen, indem unterschiedliche Paraffine gemischt werden,
• – im Temperaturbereich oberhalb der Phasenwechseltemperatur eine hohe Wärmeleitfähigkeit, und
• – im Temperaturbereich unterhalb der Phasenwechseltemperatur eine sehr geringe Wärmeleitfähigkeit.

For the purposes of thermal insulation and / or temperature stabilization, paraffins are usually used as PCM. Own this

• A high specific phase change energy,
• Favorable possibilities for setting the phase change temperature within wide limits by mixing different paraffins,
• - In the temperature range above the phase change temperature, a high thermal conductivity, and
• - In the temperature range below the phase change temperature, a very low thermal conductivity.

Especially the latter property results in the problem for many applications the specific heat transfer resistance to decrease in the PCM. Therefor are different solutions known.

Of the approach in [12] implies that the Paraffin metallic particles are mixed on the ground their contact with each other and with the metallic wall of one container also below the phase change temperature, the inlet and outlet of energy.

Of the approach in [13] implies that a Graphite foam body soaked in paraffin is and the good thermal conductivity of graphite for the entry and exit of energy is used.

Of the approach in [14] provides paraffin encapsulated in pellets a liquid medium, whose temperature is to be stabilized, should be added directly so that and dissipation of energy a large surface area and low penetration favorable Create conditions.

majority be for the said purpose on the inner wall of the container metal webs in shape of honeycomb, slats or ribs attached. So see the solutions in [15] and [16] honeycomb structures, while the solution in [2] lamellar structures used.

task

The Task of the device according to the invention is to provide passive temperature stabilization those with containers with heat sources inside not the limitation of the aforementioned passive devices subject and which, by virtue of its parameters, allows the use of active facilities to avoid temperature stabilization. The solution of the task is done by means of the device according to the invention according to the features of claim 1.

An essential aspect is that as far as possible, all heat transfers take place via the phase change material and only small thermal shunts exist. This is realized in an optimal way in containers of small dimensions, each an outer and inner shell are joined together to form a container body which accommodates the PCM in the resulting double wall. A thermal shunt is formed in this case at the joint of both shells, which is expediently designed as a frame of a door or a lid, and on the frame of the door or lid, which are also double-walled and filled with PCM. For containers of larger dimensions, a load-bearing frame of angle or hollow profile is planked on all sides with panels filled with the PCM. At least one of these panels is then executed in self-supporting construction or as a planking of a door profile frame as a door or lid.

Another aspect is that due to the all-round wrapping with the PCM, the temperature increase in the interior of the container compared to the outside temperature is slightly greater than in a container with a thin and highly thermally conductive outer skin. The phase change temperature of the PCM is therefore adjusted so that for a given heat output inside the container and given heat transfer resistance in PCM below the phase change temperature, the sum of phase change temperature and the resulting temperature increase does not exceed the upper limit of the temperature of the interior of the container. Therefore, measures are also taken, as described below, to minimize the heat transfer resistance from the interior of the container to the PCM. It is advantageous that the paraffins preferably used as PCM in the range above the phase change temperature have a good thermal conductivity. The factors and relationships are explained in the notes to the 1 , specifically shown in the formula (3).

Another aspect is that the amount of PCM is sufficiently dimensioned that in the period in which the outside temperature exceeds the phase change temperature, no complete melting of the PCM takes place and thus the temperature in the interior of the container to the sum of phase change temperature and temperature increase, see above aspect, is stabilized. The factors and relationships are explained in the notes to the 1 , specifically in formula (2).

One Another aspect is that in the Daytime low outside temperature the total amount of PCM is to be cooled below the phase change temperature, in the daytime outside temperature above the phase change temperature as large an amount of energy for stabilization be able to provide the internal temperature. Counteracting, that the preferably used as PCM paraffins in the range below the phase change temperature a low thermal conductivity own and a layer of cooled and Cured Paraffin on the outer wall the container the whole Cooling of paraffin. Especially in the warm season, when the cooling off only short and not very deep, there is this danger. It will therefore also measures taken, as described below, to the heat transfer resistance from the environment of the container into the PCM.

One to the above contrary Aspect is that in the Area over the phase change temperature, a high heat transfer resistance of the Environment of the container to be targeted in the PCM to those in the PCM stored energy as possible Completely for the Provide temperature stabilization inside the container. The above measures to reduce this heat transfer resistance therefore limited to the necessary extent, in particular become the heat conductors on the inner and outer walls so executed, that she do not touch each other and do not form a thermal bridge.

One Another aspect is that a uniform temperature distribution inside the container is a prerequisite to the effects of inventive solution all exterior surfaces of the To bring containers into action. It may therefore be appropriate an air circulation provided inside the container. Electronic subracks offer usually the possibility To integrate fan assemblies as a system component, see above that special, independent of the internals and the container adapted solutions usually not necessary, if necessary, however, are possible.

embodiment

A preferred embodiment The invention is a container with an angle frame construction. The Exterior walls of this Containers are formed on all sides by containers, which with a PCM (Phase Change Material), preferably a paraffin or mixture of paraffins having a suitable phase change temperature. The containers are designed as panels and connected to an angle profile frame or hollow profile frame, that she form the container wall. heat insulating Ensure deposits at the joints that no unwanted Heat shunt arises.

One embodiment The invention will be explained in more detail with reference to the accompanying drawings. Show it:

1 Schematic representation of the dependence of the internal temperature on an assumed daily course of the outside temperature and a phase change temperature T_CH1 of the PCM.

2 Schematic representation of the dependence of the internal temperature on an assumed daily course of the outside temperature and a phase change temperature T_CH2> T_CH1 of the PCM.

3 Basic form of the construction of the container wall, sectional view

4 Special form of construction of the container wall, sectional view

5 Exterior wall of the container wall after 4 with auxiliary shell, sectional view

6 Installation of the container walls in a container with angle profile frame, sectional view

7 Installation of the container walls in a container with hollow profile frame, sectional view

8th Installation of the container walls in a container with solid frame made of integral foam, sectional view

9 Measuring protocol on a container equipped according to the invention

Either the previous general descriptions as well as the following detailed description have only exemplary character as possible embodiments the device according to the invention and restrict the requirements not to the invention.

F

Oberfläche des Containers

P

Wärmeleistung im Inneren des Containers

d

Dicke der PCM-Schicht

M

Masse der PCM-Schicht

T_CH1

Phasenwechseltemperatur

ΔT_CH

Differenz zwischen T_CH und Außentemperatur

N_CH

spezifische Phasenwechselenergie des PCM

R_Tu

spezifischer Wärmewiderstand des PCM unterhalb von T_CH

R_To

spezifischer Wärmewiderstand des PCM oberhalb von T_CH

W_Ta

spezifischer Wärmeübergangswiderstand der Außenfläche des Containers

W_Ti

spezifischer Wärmeübergangswiderstand am der Außenfläche des Containers

1 Represents the relationships between the internal temperature 4 a container and an assumed daily course of the outside temperature 1 In the interior of the container, a power P is implemented, which without the inventive device a daily course of the internal temperature 2 with a temperature difference 3 to the outside temperature would result. The inventive device results at a phase change temperature 5 of the PCM the expected daily course of the internal temperature 4 as shown. The following parameters are important for the considerations:

F

Surface of the container

P

Heat output inside the container

d

Thickness of the PCM layer

M

Mass of the PCM layer

T_CH1

Phase change temperature

ΔT_CH

Difference between T_CH and outside temperature

N_CH

specific phase change energy of the PCM

R_Tu

specific thermal resistance of the PCM below T_CH

R_To

specific thermal resistance of the PCM above T_CH

W_Ta

specific heat transfer resistance of the outer surface of the container

W_Ti

specific heat transfer resistance on the outer surface of the container

A closed mathematical representation of relationships is not possible, since the points of discontinuity resulting from the phase change temperature prevent this. It can therefore, only in sections, the relationships are considered.

und ist auf Grund des sehr hohen spezifischen Wärmewiderstandes des PCM unterhalb von T_CH

• – praktisch ausschließlich durch d·R_Tu bestimmt
• – und dadurch wesentlich größer als die Temperaturdifferenz 3 bei Betrieb ohne die erfindungsgemäße Einrichtung.

The consideration becomes with the time period 8th started in which the entire PCM below the phase change temperature 5 has cooled and a constant temperature difference ΔTu 6 has set between the exterior and interior. This temperature difference has the value

and is below T_CH due to the very high specific thermal resistance of the PCM

• - determined almost exclusively by the R_Tu
• - And thus much larger than the temperature difference 3 during operation without the inventive device.

The period of time 9 includes the area in which the phase change has started since the inside temperature is the phase change temperature 5 has reached and is stabilized on this, but the outside temperature is still below the phase change temperature. The period of time 10 includes the range until the completion of the phase change in which the outside temperature is the phase change temperature 5 has exceeded and the internal temperature is still stabilized at the phase change temperature. For the effect of the device according to the invention is the duration of the two time periods 9 and 10 in total decisive. This results approximately by an energy consideration with

ΔT_CH here stands for the difference between T_CH and the outside temperature, averaged over the duration of the periods 9 and 10 ,

und ist auf Grund des sehr niedrigen spezifischen Wärmewiderstandes des PCM oberhalb von T_CH

• – kleiner als die Temperaturdifferenz ΔTu 6,
• – jedoch größer als die Temperaturdifferenz 3 zur Außentemperatur ohne die erfindungsgemäße Einrichtung, da das PCM als zusätzlicher Wärmewiderstand eingefügt ist.

The period of time 11 includes the range in which the entire PCM is above the phase change temperature 5 is heated. The internal temperature rises until the temperature difference ΔTo is reached 7 between exterior and interior. This temperature difference has the value

and is above T_CH due to the very low specific thermal resistance of the PCM

• - Less than the temperature difference ΔTu 6 .
• - but greater than the temperature difference 3 to the outside temperature without the device according to the invention, since the PCM is inserted as an additional thermal resistance.

The period of time 12 includes the range until the outside temperature drops to the phase change temperature 5 , where the temperature difference ΔTo is constant 7 persists.

The period of time 13 covers the range until also the internal temperature to the phase change temperature 5 has fallen off, while still constant, the temperature difference .DELTA.To 7 persists.

The period of time 14 includes the range of phase change when the internal temperature is the phase change temperature 5 has reached and is stabilized on this, and the outside temperature is below the phase change temperature.

For the effect of the device according to the invention is the duration of the time periods 13 and 14 important in total. This must be sufficiently short that in the cool time of day the entire PCM is below the phase change temperature 5 is cooled. The time duration is approximately given by the energy consideration analogous to equation (2) and is

ΔT_CH here stands for the difference between T_CH and the outside temperature, averaged over the duration of the periods 13 and 14 , t_14 thus results in greater than t_9, 10 since P counteracts the phase change.

The period of time 15 includes the area where the entire PCM is under the phase changes temperature 5 has cooled. The internal temperature drops until the temperature difference ΔTu is reached 6 between exterior and interior, which again the period 8th starts.

In 2 will affect the internal temperature 24 of a container when considering a PCM with a phase change temperature 25 is used, which is higher than the phase change temperature 5 ( 1 ). All other specifications and parameters are identical to 1 so that the general explanations to 1 also for 2 are true.

The period of time 28 corresponds to the time period 8th ( 1 ), is opposite this, however, extended as the internal temperature 24 only at a later time the phase change temperature 25 reached.

The time periods 29 and 30 correspond to the time periods 9 and 10 ( 1 ), but their duration is greater than the latter. This follows directly from equation (2), see above, since in section 30 the difference between outside temperature 1 and the phase change temperature 25 is less, so that over the time periods 29 and 30 averaged ΔT_CH enters the calculation with a lower amount.

The extension of the duration of the periods 28 . 29 and 30 due to the higher phase change temperature 25 is positive according to the idea of the invention, since there is a greater chance of the internal temperature 24 over the period of the highest outside temperature 1 away to the phase change temperature 25 to stabilize.

The period of time 31 corresponds to the time period 11 ( 1 ), the time period 33 corresponds to the time periods 12 and 13 , The duration of the time periods 31 and 33 in sum is compared to the duration of the time periods 11 . 12 and 13 shortened. Reason is the later beginning due to the greater duration of the periods 28 . 29 and 30 as well as the earlier finish, as the internal temperature 24 even at an earlier time the phase change temperature 25 reached.

The period of time 34 corresponds to the time period 14 ( 1 ). For the effect of the device according to the invention is the duration of the time periods 33 and 44 important in total. This must be sufficiently short that in the cool time of day the entire PCM is below the phase change temperature 5 is cooled. The duration is opposite to the example in 1 shortened, this results directly from equation (4), since in section 34 the difference between the outside temperature 1 and the phase change temperature 25 is larger, so that over the time periods 33 and 34 averaged ΔT_CH enters the bill with a larger amount.

The period of time 35 corresponds to the time period 15 ( 1 ).

• – ein zeitbegrenzter effektiver Wärmeschutz erreicht wird, indem durch eine möglichst hohe Phasenwechseltemperatur und die Menge des PCM die Zeitabschnitte 29, 30 (2) so ausgedehnt werden, siehe hierzu Formel (2), daß das Maximum der Außentemperatur hinreichend überbrückt wird, und
• – ein Kälteschutz in jedem Falle und unabhängig von der Phasenwechseltemperatur und der Dauer der Kälteeinwirkung durch die niedrige Wärmeleitfähigkeit des PCM erreicht wird.

The to the 1 and 2 The estimates made can not take into account and reproduce dynamic processes, for example the transient behavior at certain points. However, when comparing the statements of both pictures, it becomes clear that

• - A time-limited effective thermal protection is achieved by by the highest possible phase change temperature and the amount of PCM, the time periods 29 . 30 ( 2 ) be extended so, see formula (2) that the maximum of the outside temperature is sufficiently bridged, and
• - A cold protection is achieved in each case and regardless of the phase change temperature and the duration of the cold by the low thermal conductivity of the PCM.

In 3 the basic shape of a container wall is represented in the form of a panel. An inner shell facing the interior of the container 40 and an outer wall 41 are assembled into a tight container. The joining can be done by various methods such as an inserted seal and screwing both parts, soldering or welding or crimping. The container has a circumferential flange in the illustrated embodiment 42 for attachment to the frame of a container, other mounting and installation variants are also possible. The interior of the resulting container is filled via a not shown closable opening with the PCM. The filling takes place in the heating and liquid state of the PCM.

In the inner shell 40 is a heat conductor 43 arranged, which has good thermal contact with the inner shell and the inner shell fills in such a way that still a distance from the outer wall 41 persists. The heat conductor used is preferably an open-pored metal foam, but open metal ribbed or honeycomb structures may also be used. The preferred solution by means of an open-pored metal foam opens the possibility to pour the metal foam directly into the inner shell and to foaming, wherein a thermally conductive connection is formed by melting the contacted surface of the inner shell. The application of the other heat conductors or porous metal foam as a plate material is more expensive and requires soldering, bonding by means of a Wärmeleitklebers, pressing on an inserted heat conducting material or pressing against the inner shell without further heat transfer. In the latter methods constructive solutions are to be provided in order to produce a sufficient surface pressure a sufficient contact pressure.

The heat conductor 43 ensures the heat transfer from the interior of the container into the PCM when it has cooled below the phase change temperature. This is particularly important in the paraffin preferably used, which has a low thermal conductivity in this phase.

In 4 a special and more complex form of construction of the container wall is shown. An inner shell 45 and an outer wall 46 are assembled into a tight container. For joining and fastening by means of the circumferential flange 47 the comments apply to 3 (see above) accordingly. In the inner shell 45 is a heat conductor 48 arranged, which fills the inner shell about half of the shell height. On the outside wall 46 is a heat conductor 49 fixed so that still a distance to both the side walls of the inner shell 45 as well as the heat conductor 48 persists. For executing the heat conductors, the explanations apply to 3 (see above) accordingly.

The applications for the variants according to the 3 and 4 arise from the above aspects.

In 5 becomes the outer wall 46 the container wall after 4 with an auxiliary shell 50 shown in section. The auxiliary shell 50 opens up the possibility of pouring the preferably used open-cell metal foam directly in this auxiliary shell and to foam, wherein a thermally conductive compound by melting the contacted surface of the outer wall 46 arises.

In 6 becomes the installation of container walls 60 in a container with angle profile frame shown in section. The container walls 60 are according to the design in 3 shown, container walls according to the in 4 However, shown design can be used in the same way. The flanges of the container walls 60 are from the outside at the angle profile 61 attached. One in the cavity between container walls 60 and angle profile 61 inserted and this fully-filling heat insulating material 61 prevents unwanted thermal shunt.

In 7 becomes the installation of container walls 60 in a container with hollow profile frame shown in section. The container walls 60 are in accordance with the design in 3 shown, container walls according to the in 4 However, shown design can be used in the same way. The flanges of the container walls 60 are from the outside on the hollow profile 65 attached. Between the hollow profile 65 and the side surfaces of the container walls 60 are each heat insulating materials 66 and 67 introduced, which prevent unwanted thermal shunt.

In 8th becomes the installation of container walls 60 in a container with solid frame of integral foam shown in section. The container walls 60 are in accordance with the design in 3 shown, container walls according to the in 4 However, shown design can be used in the same way. The flanges of the container walls 60 are from outside on the massive frame 68 attached. The massive frame 68 consists of high strength closed-cell polyurethane. For the so-called integral foams made therefrom is typical that form a massive edge zone and a fine-pored foam core during foaming. Their use as a frame is a solution that manages without additional thermal insulation to avoid unwanted thermal shunts.

• – die Außentemperatur 70,
• – die Temperatur der äußeren Gehäusewandung 71,
• – die Temperatur des PCM 72 und
• – die Temperatur des Innenraumes 73.

In the embodiments according to the 6 . 7 or 8th the frame is executed at least on one side as a frame of a door or a lid or equipped with such a frame. Door or lid are as a panel according to the above embodiments (s. 3 . 4 ) in self-supporting construction or as a door frame, planked with one of said panels executed. 9 includes a measurement protocol recorded on a container equipped according to the invention. The PCM is a mixture of paraffins with a phase change temperature 74 from about 27 ° C to 28 ° C. The container walls have a design as shown in FIG 3 , the heat conductor 43 ( 3 ) is an open-pore metal foam made of aluminum. Curves are shown

• - the outside temperature 70 .
• - The temperature of the outer housing wall 71 .
• - the temperature of the PCM 72 and
• - the temperature of the interior 73 ,

• – Im Zeitabschnitt 80 liegt die Außentemperatur 70 unter der Phasenwechseltemperatur 74. Das gesamte PCM ist erhärtet und besitzt einen niedrigen Wärmeleitwert. Die Temperaturdifferenz 77 zwischen Außentemperatur 70 und Temperatur des Innenraumes 73 ist hoch.
• – Im Zeitabschnitt 81 liegt die Außentemperatur 70 über der Phasenwechseltemperatur 74 und es erfolgt die Verflüssigung des PCM, die Temperatur des PCM 72 nähert sich asymptotisch der Phasenwechseltemperatur 74. Die Verflüssigung erfolgt als Schicht an den Außen- und Innenflächen der Containerwandungen nach 3. Der hohe Wärmeleitwert dieser verflüssigten Schichten bewirkt, daß die Differenzen der Temperatur der äußeren Gehäusewandung 71 und der Temperatur des Innenraumes 73 zur Temperatur des PCM 72 sich deutlich verringern. Die Phasenwechselenergie des PCM ist deutlich hinreichend groß, um eine Überschreitung der Phasenwechseltemperatur 74 während des gesamten Zeitraumes 81 zu verhindern.
• – Im Zeitabschnitt 81 liegt die Außentemperatur 70 unterhalb der Phasenwechseltemperatur 74 und fällt steil ab. Es erfolgt die Erhärtung des PCM als Schicht an den Außenflächen der Containerwandungen nach 3. Der niedrige Wärmeleitwert dieser erhärteten Schicht bewirkt, daß die Differenz der Temperatur der äußeren Gehäusewandung 71 zur Temperatur des PCM 72 sich deutlich erhöht. Die in einem Teil des Zeitraumes 81 sichtbaren Turbulenzen der Temperatur des PCM 72 sind dadurch bedingt, daß erhärtete und abgekühlte Teile des PCM sich von der Wandung gelöst haben und durch Zirkulation im flüssigen Teil des PCM den Temperatursensor berührten.
• – Im Zeitabschnitt 83 ist das PCM gänzlich bis an die Innenflächen der Containerwandungen nach 3 erhärtet, auf Grund des niedrigen Wärmeleitwertes erhöht sich jetzt auch die Differenz der Temperatur des Innenraumes 73 zur Phasenwechseltemperatur 74.

The timeline includes a period from Saturday, 9:00 pm to Monday, 6:00 pm. Visible is that the max / min difference 75 the outside temperature of about 20 ° C in the interior of the container only a max / min difference 76 caused by about 7 ° C. The following essential phases can be seen in detail:

• - In the time period 80 is the outside temperature 70 under the phase change temperature 74 , The entire PCM is hardened and has a low thermal conductivity. The temperature difference 77 between outside temperature 70 and temperature of the interior 73 is high.
• - In the time period 81 is the outside temperature 70 above the phase change temperature 74 and there is the liquefaction of the PCM, the temperature of the PCM 72 asymptotically approaches the phase change temperature 74 , The liquefaction takes place as a layer on the outer and inner surfaces of the container walls 3 , The high thermal conductivity of these liquefied layers causes the differences in the temperature of the outer housing wall 71 and the temperature of the interior 73 to the temperature of the PCM 72 decrease significantly. The phase change energy of the PCM is clearly sufficiently large to exceed the phase change temperature 74 throughout the period 81 to prevent.
• - In the time period 81 is the outside temperature 70 below the phase change temperature 74 and falls off steeply. The hardening of the PCM takes place as a layer on the outer surfaces of the container walls 3 , The low thermal conductivity of this hardened layer causes the difference in the temperature of the outer housing wall 71 to the temperature of the PCM 72 increased significantly. That in part of the period 81 visible turbulence of the temperature of the PCM 72 are due to the fact that hardened and cooled parts of the PCM have detached from the wall and touched by circulation in the liquid part of the PCM the temperature sensor.
• - In the time period 83 the PCM is completely down to the inner surfaces of the container walls 3 hardens, due to the low thermal conductivity increases now also the difference in the temperature of the interior 73 to the phase change temperature 74 ,

Reference bibliography

• [1] Company brochure Rittal: "System Climate Control / Future Climate / Holistic Prozesssicherung "(http://www.rittal.de/de/service/Download_area/broschueren.asp?sge=SGE3&lang=D) on 30.9.2005; Stand 9/2003
• [2] JP6014983
• [3] US2003046944
• [4] EP1080957
• [5] US5811758
• [6] DE 100 30 102 A1
• [7] DE 103 22 764 A1
• [8th] DE 100 222 87
• [9] CH692574
• [10] DE19929861
• [11] DE10019931
• [12] JP61205793
• [13] DE19630073
• [14] JP60134191
• [15] JP2002130739
• [16] JP6310631

1

course the outside temperature

2

course the internal temperature, unstabilized

3

Temperature difference between 1 and 2

4

course the internal temperature at T_CH1

5

Phase change temperature T_CH1

6

Temperature difference ΔTu between 1 and 4 such as 1 and 24

7

Temperature difference ΔTo between 1 and 4 such as 1 and 24

8th

Time period with 1 and 4 below T_CH1, ΔTu 6 between 1 and 4

9

Time period with 1 below T_CH1, 4 equal to T_CH1

10

Time period with 1 above T_CH1, 4 equal to T_CH1

11

Time period with 1 and 4 above T_CH1, ΔTo 7 between 1 and 4 not reached yet

12

Time period with 1 and 4 above T_CH1, ΔTo 7 between 1 and 4

13

Time period with 1 below and 4 above T_CH1, ΔTo 7 between 1 and 4

14

Time period with 1 below T_CH1, 4 equal to T_CH1

15

Time period with 1 and 4 below T_CH1, ΔTu 6 between 1 and 4 not reached yet

24

course the internal temperature at T_CH2

25

Phase change temperature T_CH2

28

Time period with 1 and 24 below T_CH1, ΔTu 6 between 1 and 24

29

Time period with 1 below T_CH2, 24 equal to T_CH2

30

Time period with 1 above T_CH2, 24 equal to T_CH2

31

Time period with 1 and 24 above T_CH2, ΔTo 7 between 1 and 24 not reached yet

33

Time period with 1 below and 24 above T_CH2, ΔTo 7 between 1 and 24

34

Time period with 1 below T_CH2, 24 equal to T_CH2

35

Time period with 1 and 24 below T_CH2, ΔTu 6 between 1 and 24 not reached yet

40

inner shell

41

outer wall

42

flange

43

heat conductor

45

inner shell

46

outer wall

47

flange

48

heat conductor

49

heat conductor

50

auxiliary tray

60

Container wall as shown in 3 or 4

61

Angle profile frames

62

heat-insulating material

65

Dished frame

66

heat-insulating material

67

heat-insulating material

68

solid frame made of integral foam

70

outside temperature

71

temperature the outer housing wall

72

temperature of the PCM

73

temperature of the interior

74

Phase change temperature

75

Max / Min difference the outside temperature

76

Max / Min difference the temperature of the interior

77

Temperature difference between outside temperature 70 and temperature of the interior 73

80

Time interval with outside temperature 70 under the phase change temperature 74 , PCM fully hardened

81

Time period with 70 above the phase change temperature 74 , PCM in the liquefaction phase

82

Time period with 70 under the phase change temperature 74 , PCM in the hardening phase

83

Time period with 70 under the phase change temperature 74 , PCM fully hardened

Claims (11)

The present invention relates to devices for temperature stabilization in the interior of containers, cabinets and other containers, hereinafter generally referred to as containers, as well as containers equipped with these devices, which are exposed to outdoor use the daytime outdoor temperature, and in particular those containers that heat source in Inside, for example, have an electronic device, and in which without applying a temperature stabilization of the daily temperature of the interior of the container would exceed the allowable temperature range, characterized in that the containers are double-walled on all sides and the cavity between the outer and inner walls hermetically sealed and filled with a phase change material (PCM) whose phase change temperature is within the allowable temperature range of the interior of the container. Device according to claim 1, characterized that this Phase change material preferably a paraffin or mixture of Paraffins is. Device according to claim 1, characterized in that the phase change temperature PCM is set so that at given heat output inside the container and given heat transfer resistance into the PCM below the phase change temperature, the sum of phase change temperature and the resulting temperature increase the allowable upper limit does not exceed the temperature of the interior of the container. Device according to claims 1 and 3, characterized in that the quantity of the PCM is sufficiently dimensioned that in the period in which the outside temperature exceeds the phase change temperature, not complete Melting of the PCM takes place and thus the temperature in the interior of the container to the sum of phase change temperature and temperature increase stabilized becomes. Device according to claim 1, characterized in that a container in an embodiment according to the invention one outside each and inner shell, which are joined together to form a container body, which accommodates the PCM in the resulting double wall, and the joint both shells suitable as Frame of a door or a lid is, and door or lids are also double-walled and filled with PCM. Device according to claim 1, characterized in that a container in an embodiment according to the invention comprises a load-bearing frame made of angle profile ( 61 ) or hollow profile ( 65 ) or solid frame ( 68 ) of integral foam, which is provided on all sides with panels ( 60 ), which are filled with the PCM, and at least one of these panels in self-supporting construction or as a planking of a door profile frame is designed as a door or lid. Device according to Claims 1 and 6, characterized in that the panels forming the container wall are arranged on the inner shell facing the interior of the container ( 40 ) a heat conductor projecting into the PCM ( 43 ), which is connected to the wall with good thermal conductivity. Device according to Claims 1 and 6, characterized in that the panels forming the container wall are located both on the inner shell facing the interior of the container ( 45 ) as well as on the outer wall ( 46 ) in the PCM protruding heat conductor ( 48 . 49 ), which are connected to the walls with good thermal conductivity and have no connection with each other. Device according to Claims 1 and 7, characterized in that the heat conductor ( 43 ) - preferably made of open-pored metal foam, which is preferably in the inner shell ( 40 ) is poured and by melting during the casting process, the heat-conducting contact with the inner shell ( 40 ), or - consists of open-pore metal foam or open rib or honeycomb structures made of metal, the heat-conducting contact with the inner shell ( 40 ) by soldering, bonding by means of a Wärmeleitklebers, pressing on a pickled heat conducting material or pressing on the inner shell without further heat promoters. Device according to Claims 1 and 8, characterized in that the heat conductor ( 49 ) - preferably consists of open-pored metal foam, which preferably in an auxiliary shell ( 50 ) is poured and by melting during the casting process, the heat-conducting contact with the outer wall ( 46 ), or - is made of open-pored metal foam or open rib or honeycomb structures made of metal, the heat-conducting contact with the outer wall ( 46 ) by soldering, bonding by means of a Wärmeleitklebers, pressing on an inserted heat conducting material or pressing on the outer wall without further heat promoters. Device according to Claims 1 and 6, characterized in that - in the case of a container with angle profile frames ( 61 ) in the cavity between the angle profile frame and the panels ( 60 ) heat insulating material ( 62 ) and - in the case of a container with hollow profile frame ( 65 ) in the cavities between the hollow profile frame and the panels ( 60 ) heat insulating materials ( 66 . 67 ) are introduced so that they prevent unwanted thermal shunt.