阅读说明：本技术 传热设备和构件 (Heat transfer apparatus and components ) 是由 弗洛里安·施瓦茨 于 2020-03-03 设计创作，主要内容包括：本发明涉及一种传热设备(1)和电气或电子构件(4),其中,传热设备(1)包括至少一个散热结构(2)和至少一个加热室(3),其中,散热结构(2)和加热室(3)与封闭的热循环(7)耦合,其中,散热结构(2)包括输出通道(2.1),输出通道从加热室(3)引出并且输出通道在一个远离加热室的端部(2.2)处通入至少一个回流通道(2.3)中,其中,回流通道(2.3)在尺寸方面小于输出通道(2.1)并且通入加热室(3)中,并且其中,至少一个加热室(3)是沸腾室或蒸汽室,并且至少一个散热结构(2)是具有蒸汽区域(2.4)和液体区域(2.5)的通道结构,其中,加热室(3)和散热结构(2)共同形成脉动的或振荡的加热结构机制。(The invention relates to a heat transfer device (1) and an electrical or electronic component (4), wherein the heat transfer device (1) comprises at least one heat dissipation structure (2) and at least one heating chamber (3), wherein the heat dissipation structure (2) and the heating chamber (3) are coupled to a closed thermal circuit (7), wherein the heat dissipation structure (2) comprises an outlet channel (2.1) which leads out of the heating chamber (3) and which opens into at least one return channel (2.3) at an end (2.2) remote from the heating chamber, wherein the return channel (2.3) is smaller in size than the outlet channel (2.1) and opens into the heating chamber (3), and wherein the at least one heating chamber (3) is a boiling chamber or a steam chamber and the at least one heat dissipation structure (2) is a channel structure having a steam region (2.4) and a liquid region (2.5), wherein the heating chamber (3) and the heat dissipation structure (2) together form a pulsating or oscillating heating structure mechanism.)

1. A heat transfer device (1) comprising:

-at least one heat dissipation structure (2), and

-at least one heating chamber (3),

wherein the heat dissipation structure (2) and the heating chamber (3) are coupled with a closed thermal cycle (7),

wherein the heat dissipation structure (2) comprises

-an outlet channel (2.1) which leads out of the heating chamber (3) and which opens out at an end (2.2) remote from the heating chamber (3) into at least one return channel (2.3),

wherein the return channel (2.3) is smaller in size than the outlet channel (2.1) and opens into the heating chamber (3), and wherein at least one heating chamber (3) is a boiling chamber or a steam chamber and at least one heat dissipation structure (2) is a channel structure with a steam region (2.4) and a liquid region (2.5), wherein the heating chamber (3) and the heat dissipation structure (2) together form a pulsating or oscillating heating structure mechanism.

2. The heat transfer device (1) according to claim 1, wherein the output channel (2.1) is divided into at least two or more return channels (2.3) at the end (2.2) remote from the heating chamber (3), which return channels are smaller in size than the output channels (2.1), respectively, and which return channels open into the heat transfer chamber (3) separately from one another.

3. The heat transfer device (1) according to claim 1 or 2, wherein the outlet channel (2.1) and at least one of the return channels (2.3) are located in a plane (E, E1).

4. The heat transfer device (1) according to claim 1 or 2, wherein the outlet channel (2.1) extends in at least one first plane (E1) and at least one return channel (2.3) extends in at least one second plane (E2) offset with respect to at least one first plane (E1).

5. The heat transfer device (1) according to any of the preceding claims, wherein the inner diameter (D1) of the outlet channel (2.1) is larger than the inner diameter (D2) of at least one of the return channels (2.3).

6. The heat transfer device (1) according to any of the preceding claims, wherein the heating chamber (3) is configured as a boiling chamber or a steam chamber which is provided with a structure (12) at least one inner surface or inner surfaces (3.1) opposite to each other.

7. The heat transfer device (1) according to claim 6, wherein the structure (12) is configured such that the inner chamber (3.2) of the heating chamber (3) has a varying cross-section.

8. Heat transfer device (1) according to claim 6 or 7, wherein the inner chamber (3.2) of the heating chamber (3) has a plurality of cross-sectional constrictions (13) expanding in the longitudinal direction.

9. The heat transfer device (1) according to claim 8, wherein the cross-sectional constriction (13) is formed by mutually opposite projections (3.3) which project from mutually opposite inner surfaces (3.1) into the inner chamber (3.2).

10. The heat transfer device (1) according to any of the preceding claims, wherein the heat dissipation structure (2) is arranged symmetrically or asymmetrically around the heating chamber (3).

11. An electrical or electronic component (4) comprising a power element, in particular a power semiconductor element, which is thermally coupled with a heat transfer device (1) according to any one of the preceding claims.

12. The electrical or electronic component (4) according to claim 11, wherein the heat transfer device (1) is arranged below, above or inside the power element.

13. Electrical or electronic component (4) according to claim 11 or 12, wherein the heating chamber (3) is arranged below, above or inside the power element with respect to the power element.

14. The electrical or electronic component (4) according to any one of claims 11 to 13, wherein the heat dissipation structure (2) extends in one or more planes (E, E1 to E2) in a radial direction away from the heating chamber (3) and the power element.

Technical Field

The present invention relates to a heat transfer device and an electric or electronic component.

Background

The electrical or electronic component can be part of an integrated circuit arranged on the carrier plate. In this case, electrical or electronic components (for example resistors or power semiconductors) can generate heat, which cannot be dissipated sufficiently via the carrier plate. Therefore, cooling plates are known in the prior art, which are arranged between the electrical/electronic components and the carrier plate or at the carrier plate for thermal coupling in order to dissipate heat from the electrical/electronic components.

The power density of the electrical/electronic components and thus the permissible range of use of the connection is limited by the so-called barrier layer temperature of the semiconductor element from which the electrical or electronic components are formed. Thus, the maximum allowable temperature limits the use and structure of electrical or electronic components. Furthermore, large temperature changes reduce the service life of the semiconductor element and its connections and thus of the overall electrical or electronic component. Therefore, thermal connections at the electrical or electronic components and in particular at the semiconductor elements thereof are important. The thermal connection is influenced in particular by the following parameters: the dimensions of the cooling and contact surfaces for the electrical or electronic component, the material parameters (e.g. the thermal conductivity), the heat transfer coefficient and the temperature difference between the heat source (e.g. the semiconductor element of the electrical or electronic component) and the heat sink (e.g. the cooling element).

To improve the thermal connection, it is therefore known to spread the heat generated at the electrical or electronic component over a large area. For this purpose, heat transfer devices are known which comprise a central heating chamber, in particular a steam chamber, from which symmetrical microchannels emerge and which operate on the principle of pulsating heating structures (heat pipe principle) as a result of pump cooling. Such a Heat Transfer device is described, for example, in the article "Heat Transfer performance of a reactive silicon microchannel Heat sink treated to pulse flow" by S.xu et al (Shanglong Xu, Weijie Wang, Juang Fang, Chun-Nam Wong) in International Journal of Heat and Mass Transfer 81, 2015, pages 33 to 40, Journal pages: www.elsevier.com/locate/ijhmt.

Here, if too much liquid is located inside the heating chamber, the pulsating heating structure cannot be turned on. If too much steam is located inside the heating chamber, the electrical/electronic components can be overheated.

From US 5937936 a heat sink for a portable electronic device is known, wherein a fluid is evaporated in a heat receiving area of a heat pipe, and heat is transported by the heat pipe into a further area, where it is re-liquefied and returned to the heat receiving area.

Disclosure of Invention

The invention is therefore based on the object of safely providing a heat transfer device, in particular a safe opening of a heat transfer device, which enables heat transfer and heat conduction.

The object according to the invention is achieved by a heat transfer device having the features of claim 1. With regard to the electronic component, the object according to the invention is achieved by the features of claim 11.

Improvements of the invention are the subject of the dependent claims.

The heat transfer device according to the invention comprises at least one heat dissipation structure and at least one heating chamber, in particular a hot chamber, wherein the heat dissipation structure and the heating chamber are coupled to a closed thermal circuit, wherein the heat dissipation structure comprises an outlet channel which leads out of the heating chamber and opens into at least one return channel at an end remote from the heating chamber, and wherein the return channel is smaller in size than the outlet channel and opens into the heating chamber.

Here, the at least one heating or heating chamber is a boiling or steam chamber and the at least one heat dissipation structure is a channel structure with a steam region and a liquid region, wherein the heating chamber and the heat dissipation structure together form a pulsating or oscillating heating structure mechanism with a two-phase flow (also referred to as a pulsating heat pipe mechanism).

In the case of pulsating heating mechanisms (pulsating heat pipe mechanisms), a pulsating or oscillating guidance or return of a fluid, for example a cooling medium, takes place by means of capillary forces in channels, for example outlet and return channels, heat pipes or so-called pulsating heat pipes. The pulsating heating structure mechanism represents an efficient heat transfer possibility. Here, for example, a liquid, in particular a cooling medium (for example water, acetone, methanol or ethanol), is evaporated here, i.e. heat is absorbed in the region of the heat receiver of the fluid, for example in the heating chamber and thus in the region of the power element of the electrical or electronic component, and is liquefied, for example, where the heat is released, for example already in the heating chamber and/or a heat sink, in particular a symmetrical or asymmetrical channel structure. Thus, heat transfer occurs through each type of thawing, evaporation, vaporization, or phase transition. The heat reception in the fluid leads to an increase in the energy level of the fluid, in particular to an increase in the pressure in the thermal cycle, and as a result of the pressure increase leads to a phase transition of the fluid, for example from a solid state to a liquid state or from a liquid state to a gas state or vice versa.

A fluid, such as a cooling medium or a cooling medium, is thus present in two phases in a closed cycle. Furthermore, the heat dissipation structures, in particular the channels (e.g. microchannel structures or capillary structures), are arranged symmetrically around the heating chamber. Furthermore, the heating chamber and the heat dissipation structure are first vacuum-sealed and then partially filled with a fluid, cooling medium. Thus, two phases are already present in the cycle at the start of operation of the heat transfer device.

Such heat transfer devices with such heat dissipation structures are illustrated in the form of channels, in particular microchannel structures or capillary structures, by heat sinks with large heat transfer areas, wherein convective heat transfer is also possible by means of the heat dissipation structures in a pulsating or oscillating flow of a fluid (e.g. a cooling medium). The design of the large-size outlet channel leading from the heating chamber or hot chamber enables an improved distribution and removal of the heat flow out of the heating chamber, whereby an improved heat dissipation is obtained.

On the other hand, it is proposed that the outlet channel is divided into two or more return channels at the end remote from the heating chamber, the return channels being smaller in size than the outlet channels and opening into the heat transfer chamber separately from one another. This design and distribution of the heat flow in the two or more return channels enables an improved heat transfer and an improved liquefaction. The return channel and the outlet channel are designed such that the mass flow of the outlet channel is equal to the sum of the partial mass flows of the return channel.

On the other hand, it is proposed that smaller return channels, in particular other partial return channels, are distributed in a shape-like manner or are continuously branched in the region of the outer edge of the heat transfer device. Thus, a flow distribution with minimal pressure loss is produced with simultaneous maximum area usage and area distribution. This results in an improvement of the liquefaction in the return channel and thus an improvement of the heat transfer.

Another possible embodiment provides that the outlet channel and the at least one return channel are in one plane. This enables a flat construction of the heat transfer device.

An alternative embodiment provides that the outlet channel runs in at least one first plane and the at least one return channel runs in at least one second plane offset from the first plane. In other words, the return channel or return channels are led back lower to one or more planes. This results in a heat dissipation structure with two or more channel structures that overlap one another, namely at least one upper outlet channel structure and at least one lower return channel structure. In addition, other fractal and/or three-dimensional geometries of the heat dissipation structure are possible. The three-dimensional geometry of such a heat transfer device allows the integration, in particular the thermal coupling, of the heat transfer device with the rib structure of the component to be cooled.

A simple embodiment provides that the inner diameter of the outlet channel is greater than the inner diameter of the at least one return channel. This enables heat transfer with minimal pressure loss with simultaneous maximum area usage and area distribution. Furthermore, such a cross-sectional constriction enables an acceleration of the flow from the outlet channel to the adjacent return channel. This causes a pulsating or oscillating flow in a closed thermal cycle.

In a further aspect, it is provided that the heating or heating chamber is designed as a boiling or steam chamber, which is provided with a structure on at least one or on mutually opposite inner surfaces. By this surface structure of the inner side projecting into the heating chamber, the optimal ratio of liquid/fluid and vapour can be adjusted in the heating chamber. The structure is designed, for example, such that the inner chamber of the heating chamber, in particular of the boiling chamber or steam chamber, has a varying cross section.

The inner space of the heating chamber, in particular of the boiling chamber or steam chamber, can have, for example, a plurality of spaced constrictions along its longitudinal extent, for example a horizontal extension of the heating chamber. By means of this point-by-point cross-sectional change, in particular a constriction (e.g. a cross-sectional constriction), the so-called capillary forces in the heating chamber increase.

In a possible embodiment, the constrictions (e.g. cross-sectional constrictions) are formed by projections lying opposite one another, which project from inner surfaces lying opposite one another, e.g. inner chamber walls, into the inner chamber. This pattern of internal structures in the heating or hot chamber's internal chamber facilitates the so-called onset of a frozen fluid (e.g., cooling medium), such as a cooling fluid or cooling medium.

Another aspect proposes that the heat transfer device can comprise more than one heating chamber, which are part of a single closed thermal cycle. Alternatively, each heating chamber can have an associated closed thermal circuit, wherein the closed thermal circuit can again be thermally coupled indirectly or directly. Alternatively, the partial cycles of heat can also be separated from one another. The channels of the heat dissipating structure can also be arranged symmetrically around one or more heating chambers.

Another aspect of the invention relates to an electrical or electronic component comprising a power element, in particular a power semiconductor, which is thermally coupled to a heat transfer device.

In a possible embodiment, the heat transfer device can be arranged below, above or inside the power element. This enables a direct and rapid heat transfer and thus a rapid heat removal of the hot power element. The heating chamber is arranged, for example, in the lower part of the power element in parallel with the power element.

The heat dissipation structure extends in one or more planes in the radial direction away from the heating chamber and the power element. This enables an improved area usage and area distribution for improved heat conduction and improved heat transfer.

Drawings

The above-described features, characteristics and advantages of the present invention and the manner and method of attaining them will become more apparent from the following description of the embodiments taken in conjunction with the accompanying drawings. Here, there are shown:

fig. 1 shows a schematic cross-sectional view of a heat transfer device arranged below an electrical or electronic component;

FIG. 2 shows a schematic perspective view of a heat transfer device having an electrical or electronic component;

FIG. 3 shows a schematic top view of a heating chamber with heat dissipating structures, the heating chambers being connected to each other to form a closed thermal cycle;

figures 4 to 7 respectively show schematic top views of a heating chamber with alternative heat dissipating structures connected to each other to form a closed thermal cycle;

FIG. 8 shows a schematic cross-sectional view of a heating chamber with an inside surface structure;

fig. 9 shows a schematic sectional illustration of a heating chamber with an inner surface structure and the resulting improved, in particular symmetrical, fluid occupation in the heating chamber; and

fig. 10 shows a schematic cross-sectional view of a conventional heating chamber without an inner surface structure and the resulting asymmetrical fluid occupation in the heating chamber according to the prior art.

Parts corresponding to each other in all figures are provided with the same reference numerals.

Detailed Description

Fig. 1 shows a schematic cross-sectional view of a heat transfer device 1.

The heat transfer device 1 comprises at least one heat dissipating structure 2 and at least one heating chamber 3.

The heat transfer device 1 is arranged at a lower portion of an electric or electronic member 4 (hereinafter abbreviated as member 4). Alternatively, the heat transfer device 1 can also be arranged on or in the upper part of the component 4 (not further shown).

The component 4 is, for example, part of an integrated circuit, but also of a carrier board 5, in particular of a printed circuit board. The component 4 is, for example, a power element, in particular a power semiconductor element, which generates heat W during operation and radiates heat according to arrow PF 1.

Ideally, a heat sink 6 can be provided for heat dissipation, which is arranged, for example, on the side of the carrier plate 5 opposite the component 4. The heat sink 6 can have ribs 6.1 for distributing the heat W and for improved dissipation, so that the heat W is distributed and dissipated over a large surface.

Fig. 2 shows a schematic perspective view of a possible embodiment of a heat transfer device 1 with an electrical or electronic component 4, in particular a power semiconductor element (e.g. a power chip).

The heat transfer device 1 comprises a heat dissipating structure 2 and a heating chamber 3, which is coupled to a closed thermal cycle 7 in which a fluid 7, in particular a cooling medium (e.g. water, methanol, ethanol or acetone), flows.

The heating chamber 3 is in particular a hot chamber which is arranged directly below the component 4 and to which a thermal load is applied by the heat W radiated by the component 4. The fluid F arranged in the heating chamber 3 can be heated to the boiling point or evaporation point depending on the degree of the radiated heat W, whereby the pressure in the thermal cycle 7 rises and the pulsating flow S is regulated without a pump in the thermal cycle 7 with the liquid phase FP or the vapor phase DP. Here, after partial filling with fluid F, thermal cycle 7 is in thermodynamic equilibrium in which two phases (liquid phase FP or vapor phase DP) are present. The pressure in the thermal cycle 7 is raised by local heating. This results in a pulsating or oscillating flow S without a pump. Here, the fluid F can be locally evaporated and liquefied, and therefore, the heat conduction is increased. The pulsating or oscillating flow S (hereinafter abbreviated to pulsating flow S) is thus a two-phase flow, wherein the fluid F is present in the liquid phase FP and/or the vapor phase DP along the closed thermal cycle 7. The heat dissipation structure 2 thus has a vapor region 2.4 and a liquid region 2.5.

The heating chamber 3 can also be called a vapor chamber or a boiling chamber depending on the phase of the liquid F.

The heat dissipation structure 2 comprises an outlet channel 2.1 which leads out of the heating chamber 3 and opens out at an end 2.2 remote from the heating chamber 3 into at least one return channel 2.3 which then opens out into the heating chamber 3.

The fluid F flowing out of the heating chamber 3 flows back into the heating chamber 3, for example, via the outlet channel 2.1 and the return channel 2.3 in the manner of a cooling circuit 8, so that a closed thermal cycle 7 is formed.

In this case, a plurality of cooling circuits 8 can be arranged symmetrically distributed around the heating chamber 3, which is arranged in particular in the middle or in the center. The cooling circuits 8 in particular have substantially the same shape, size and dimensions. Alternatively, the cooling circuits can also differ from one another.

The return channel 2.3 is smaller in size than the outlet channel 2.1, as shown in detail in fig. 3.

Fig. 3 shows in detail one of the cooling circuits 8 of the closed thermal cycle 7 with a central heating chamber 3 and a heat dissipation structure 2, which are connected to each other to the cooling circuits 8 and thus to part of the circuits of the closed thermal cycle 7.

The design of the larger size outlet channel 2.1 leading from the heating chamber 3 enables an improved distribution and leading of the fluid flow out of the heating chamber 3, and thus an improved heat transfer.

All cooling circuits 8 are, for example, identical, i.e. the outlet channel 2.1 of the cooling circuit is larger in size than the return channel 2.3 of the cooling circuit.

The inner diameter D1 of the outlet channel 2.1 is for example larger than the inner diameter D2 of the return channel 2.3. This enables heat transfer with minimal pressure loss with simultaneous maximum area usage and area distribution. Furthermore, such a cross-sectional constriction 13 enables an acceleration of the flow from the outlet channel 2.1 to the adjacent return channel 2.3. This causes and promotes a pulsating flow S in the closed thermal cycle 7.

Such a heat transfer device 1 with such a heat dissipation structure 2 in the form of a channel structure, in particular a microchannel structure or a capillary structure, enables a heat sink with a large heat transfer area, wherein convective heat transfer is also possible via the heat dissipation structure 2 in accordance with the pulsating flow S of the fluid F.

Fig. 4 shows a schematic plan view of a heating chamber 3 with an alternative heat dissipation structure 2 in the form of a double cooling circuit 9, which consists of two individual cooling circuits 8.

The outlet channel 2.1 is divided at the end 2.2 remote from the heating chamber 3 into at least two return channels 2.3, which are each smaller in size than the outlet channel 2.1 and which open out into the heat transfer chamber 3 separately from one another. Thus, two cooling circuits 8 are formed, which are formed by a common outlet channel 2.1 and two divided return channels 2.3. The common outlet channel 2.1 is larger in size than the two outlet return channels 2.3. In particular, the common outlet channel 2.1 has an inner diameter D1 which is greater than the inner diameter D2 of the respective return channel 2.3. The return channels 2.3 can have substantially the same shape, size and dimensions. The inner diameter D2 of the return channel 2.3 is in particular identical.

This design and distribution of the pulsating or oscillating flow S of the outlet channel 2.1 in the two or more return channels 2.3 enables an improved heat transfer and an improved liquefaction. The return channel 2.3 and the common outlet channel 2.1 are designed in such a way that the mass flow of the outlet channel 2.1 is equal to the sum of the partial mass flows of the return channels 2.3.

Fig. 5 shows in detail the heat transfer device 1 according to fig. 4 with a plurality of double cooling circuits 9 arranged symmetrically distributed around the heating chamber 3. The heat transfer device 1 is for example arranged on a substrate 10, which is arranged on a carrier plate 5. The substrate 10 and the carrier plate 5 can be a component 4 or a separate component 4 according to an embodiment.

Fig. 6 shows a schematic top view of a heating chamber 3 with an alternative heat dissipation structure 2 in the form of a fractal division of the return channel 2.3 into more sub-return channels 2.6.

The common outlet channel 2.1 is first divided into two return channels 2.3, from which the partial return channels 2.6 are led in each case. The channel division is realized here at the end 2.2 of the heat dissipation structure 2 remote from the heating chamber 3. This fractal channel division enables flow distribution with minimal pressure loss with simultaneous maximum area usage and area distribution.

According to fig. 1 to 6, in different embodiments of the heat transfer device 1, the heat dissipation structure 2 is arranged in a plane E. This means that the outlet channel 2.1 and the return channel 2.3 run in the same plane E.

Fig. 7 shows a schematic top view of a further alternative embodiment of a heat transfer device 1 with a heat dissipation structure 2, which extends in two planes E1, E2. The outlet channel 2.1 extends, for example, in a first plane E1 and in a second plane E2 offset with respect to the first plane E1 leads from the outlet channel 2.1 to a return channel 2.3 and from the return channel 2.3 to a return sub-channel 2.6.

In other words, the return channel or channels 2.3 and the sub-return channels 2.6 are led back into a second plane E2 which is lower than the first plane E1. Thereby, a heat dissipation structure 2 having at least two channel structures (i.e., an upper output channel structure and a lower return channel structure) overlapping each other is produced. Other fractal and/or three-dimensional geometries of the heat dissipation structure 2 are possible here. Fig. 7 shows a heat dissipation structure 2 in the form of a capillary channel structure with strongly branched return channels 2.3 and sub-return channels 2.6, which are smaller in size than the corresponding output channels 2.1.

All embodiments according to fig. 1 to 7 are identical, i.e. the heat dissipation structure 2 extends in a radial direction away from the heating chamber 3, wherein the heating chamber 3 is arranged at a lower portion of the member 4.

Fig. 8 shows a schematic cross-sectional view of the heating chamber 3 with the structure 12. The structures 12 are arranged in the form of surface structures on at least one of the heating chambers 3 or on the mutually opposite inner surfaces 3.1.

The structure 12 is a surface structure of an inner side projecting into the heating chamber 3. The structure 12 is designed, for example, such that the interior 3.2 of the heating chamber 3 has a varying cross section.

The interior 3.2 can have, for example, a plurality of cross-sectional constrictions 13 along the longitudinal extent. The cross-sectional constriction 13 is formed, for example, by a projection 3.3 (e.g. a rib, nub, web) which projects into the interior 3.2. The projections 3.3 are arranged in pairs, wherein a pair of projections 3.3 projects from the inner surfaces 3.1 opposite one another into the interior 3.2. In this case, the pair of projections 3.3 projects into the interior 3.2 such that their free projection ends are spaced apart from one another, whereby one of the cross-sectional constrictions 13 is formed in the interior 3.2. The so-called capillary force of the fluid F in the channel of the closed thermal cycle 7 is increased by this point-by-point cross-sectional constriction 13.

Fig. 9 shows a schematic sectional view of a heating chamber 3 with an inner structure 12 and the resulting improved, in particular symmetrical, fluid occupation in the heating chamber 3. The capillary force of the fluid F in the heating chamber 3 is increased by the cross-sectional constriction 13, so that the fluid F is present in the form of a liquid phase FP in the region of the respective cross-sectional constriction 13.

This pattern of the inner structure 12 in the inner chamber 3.2 of the heating chamber 3 leads to a symmetrical fluid occupation in the heating chamber 3 and thus simplifies the so-called start-up of the heat transfer device 1 and the pulsating heating structure mechanism in the case of frozen fluid F in the starting phase.

Fig. 10 shows a schematic sectional view of a conventional heating chamber without an inner structure 12 according to the prior art and the resulting asymmetrical fluid occupation inside the heating chamber 3.

Although the invention is illustrated and described in further detail by means of preferred embodiments, the invention is not limited by the disclosed examples and further variants can be derived by the person skilled in the art without departing from the scope of protection of the invention.