JPH04227478A - Manufacture of heat accumulation means - Google Patents

Abstract

PURPOSE: To manufacture a latent heat storage apparatus for car heater operating with heat from an engine economically in a short time while insulating inner and outer containers well and suppressing heat loss. CONSTITUTION: A heat storage apparatus comprises a housing including an outer container 12 and an inner container 14 disposed therein through an insulating band, and a heat storage core 16 disposed in the inner container 14 while having at least one chamber for receiving heat storage medium, wherein the chamber is sectioned by a partition wall from at least one channel for heat transfer medium and further provided with inlet and outlet pipes therefor connected with the channel and extended outward through the insulating band 36.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION The present invention relates to a housing consisting of an outer container including an insulating band therebetween and an inner container arranged at intervals; a heat storage core including at least one chamber for inclusion therein, said chamber being separated from at least one flow path for a heat transfer medium by a partition wall;
further comprising an inlet tube and an outlet tube for the heat transfer medium;
The tube is connected to the flow path and extends outwardly through an insulating strip that is baked out and evacuated in the housing to evacuate the vehicle, which operates with heat from the engine. It relates to a method for manufacturing heat storage means, in particular in the form of latent heat storage means, for a heating device, and to a heat storage means for carrying out this method.

[0002] In the case of automobile heating systems, it is common practice to store heat overnight so that when the car starts in the morning, the engine cooling water has sufficient heat stored until it reaches operating temperature. It has a purpose. Taking into account that automobile structures generally require low weight and small size, the quality of insulation desired for this heat storage means is such that it surrounds the heat storage core on all sides and This could only be achieved by having a double walled housing with an insulating vacuum inside. In this respect, this may be a matter of high vacuum or insulation, for example in the form of microporous materials such as powders or fibers, the space between which is additionally evacuated. Accordingly, a housing is utilized that includes an outer vessel and an inner vessel, with inlet and outlet tubes extending outwardly for the heat transfer medium. Heat loss will therefore occur by convection and conduction of heat transfer media, such as in the form of engine cooling water or engine exhaust gases. Such insulating heat storage means are described, for example, in DE 36 14 318 A.

The efficiency of the insulation of such heat storage means depends, on the one hand, on the use of previously known vacuum techniques and, on the other hand, on the hermetic design of the insulating container, including the inner and outer container, and on the solid construction. Heat conduction results in the inlet and outlet pipes,
as well as means for supporting the inner container within the outer container. Heat transfer through inlet and outlet tubes with small cross-sections and long routes may be kept relatively low.

After the mechanical part of the production of such heat storage housings, the desired insulation effect can be achieved within a few minutes by evacuation of the gas from the insulation strips. However, this insulation effect is not permanent. This is because the material covers the surfaces of the external and internal containers delimiting the insulation strip, as well as any heat dissipation shields placed on the insulation strip, as well as on the surfaces of the microscopic insulating material and the mandatory attachments to the insulation strip, i.e. the inlet and outlet pipes. , and the means supporting the inner container, such substances will eventually evaporate, resulting in an increase in the pressure in the insulation band and a reduction in the insulating effect of the vacuum.

For this reason, the vacuum-insulated container is degassed for an extended period after the mechanical manufacture of the equipment, and the insulation strip is continuously evacuated. In order to reduce the degassing time to, for example, 24 hours, the insulating container is heated to a high temperature while being evacuated and is then baked out.
out). Experience has shown that an increase of 10° C. reduces degassing time by half.

Furthermore, it is known that the main source of contamination of vacuum vessels is moisture absorbed by the walls. To remove this moisture, three temperatures are possible: a low evaporation rate at about 120°C, a high evaporation rate at 180°C, and a practically 100 percent evaporation rate at about 360°C.

It is also known that during degassing, its long-term effect depends on the minimum temperature reaching the surface of the insulation strip. Therefore, for the above effect to be provided, all surfaces defining the insulation zone would have to reach or exceed a minimum temperature.

For complete application to automobile construction, 1
Requires bakeout in the second stage range of 80°C,
Long-term effects of vacuum are required. However, the operating temperature of this type of heat storage means is 90°C, and the required maximum temperature is 125°C.
It is ℃. Therefore, the bakeout temperature required for the production of a quality vacuum substantially exceeds the operating temperature that should be expected later. As a result, in the process of its production, for example by increasing the vapor pressure of the heat storage medium used, or
The problem arises of thermal damage to the heat storage means due to deterioration due to thermal expansion of the supporting parts within the heat storage core, such as synthetic resin.

[0009]

SUMMARY OF THE INVENTION Therefore, one object of this invention is to
The object of the present invention is to devise a method for the production of heat storage means of the type mentioned at the outset, such that good quality insulation can be produced in an economically acceptable and substantially shorter time period and without thermal damage. More specifically, the insulation should be sufficiently durable for long-term use in automobiles. Furthermore, the heat storage means should be designed in such a way that the method according to the invention can be used in its manufacture.

[0010] To achieve the above and other objects as will be apparent from this specification, claims and drawings, the bakeout is carried out at a temperature substantially above the operating temperature of the heat storage means, in which point the heat storage core The temperature-sensitive components of the device are protected from damage due to temperature effects.

This type of protection of the temperature sensitive components of the heat storage core depends on the type of possible damage to the heat storage core and, as mentioned above, essentially depends on the thermal sensitivity of the materials used and/or
Alternatively, it may be a direct result of material loading caused by thermal expansion of the mechanical components of the heat storage core, or an excessively high vapor pressure of the heat storage medium.

[0012]According to a further possible development of the invention, the heat storage core is thermally insulated from the insulation strip, at least during the bakeout, and according to a further advantageous development, the insulation space between the heat storage core and the inner container is thermally insulated from the insulation strip at least during the bakeout. During bakeout, it is either filled with a gas of low thermal conductivity or evacuated.

According to a further advantageous embodiment of the invention,
During the bakeout of the insulation strip, the high vapor pressure acting on the section of the chamber containing the heat storage medium is supported, and according to an advantageous embodiment of the invention, the static pressure compensates the high vapor pressure of the heat storage medium during the bakeout. In order to do this, a flow path is formed in the inner container.

According to a further advantageous development of the invention, during bakeout the inner container has a temperature-dependent vapor pressure function.
It is filled with a liquid selected to compensate the vapor pressure of the heat storage medium during bakeout, and the liquid is sealed in the inner container during bakeout. Preferably, the inner container is filled with ethylene glycol in this case.

[0015] According to another advantageous development of the invention, during the bakeout the cooling medium is caused to pass through the flow path;
For example, the cooling medium is a mixture of ethylene glycol and water.

In the case of heat storage means using an insulating gap between the outer surface and the inner container surrounding the heat storage core between two end faces, in which the flow paths flowing through the heat storage core end and respectively begin, such that the flow of the cooling medium through the insulating gap is interrupted between the end faces, thereby heating the medium whose flow is impeded and preventing any undesired cooling of the inner container during bakeout; There is a possibility of further advantageous development.

In the case of heat storage means using an insulating gap between the outer surface and the inner container, which surrounds the heat storage core between the two end faces and in which the flow channels flowing through the heat storage core end and respectively begin. , in a highly advantageous further form of the invention, at the beginning of the bakeout, the cooling medium is heated, generally in the range of the operating temperature of the heat storage means, and during the bakeout,
It is characterized by being kept within that temperature range. As a result, the desired bakeout temperature is achieved faster and excessive cooling of the inner container is avoided during bakeout.

Evacuating the insulation strip is an expensive operation, so it is desirable that the duration of this step be as short as possible. Therefore, according to a further embodiment of the invention, the heat storage core is first preheated with a liquid acting as a heat transfer medium at the maximum permissible temperature of the heat storage core and is kept at this temperature level until the bakeout operation is completed.

In this respect, the liquid acts as a heating medium until the desired temperature level is reached and then as a cooling medium until the bakeout operation is terminated with a bakeout temperature above the maximum permissible temperature of the thermal storage core. do.

According to a further advantageous development of the invention, the method is such that the evacuation of the insulation strip is started with a time lag after the preheating of the heat storage core, if this preheated heat storage core is used It is more particularly advantageous if the heat storage means are moved to a bakeout station where the insulation strip is baked out and evacuated.

[0021] To carry out this method, an external container and
a housing comprising an inner container disposed in spaced relation to an outer container to include an insulating strip therebetween; and a heat storage core having at least one chamber disposed within the inner container and containing a heat storage medium therein. the chamber is separated from at least one flow path for a heat transfer medium by a partition wall, and further includes an inlet tube and an outlet tube for the heat transfer medium, the tubes being connected to the flow path; and such heat storage means extending outwardly via the insulating strip,
It further includes the development that the heat storage core is supported in a gap with the inner wall surface of the inner container, and the space between the inner container and the heat storage core is connected to the flow. Therefore, during the bakeout of the space between the inner container and the heat storage core, the space between the inner container and the heat storage core is communicated to the outside and during operation of the heat exchanger,
There is a possibility of supplying an insulating gas or a vacuum via a conductive connection providing a flow connection of the heat storage core. However, it is also possible that during the bakeout a static pressure is built up in the flow path, for example using an adiabatic gas, which pressure compensates for the high vapor pressure of the heat storage medium that occurs during the bakeout. Furthermore, during the bakeout phase there is the possibility of filling a liquid, for example ethylene glycol, via a pipe connection and having the temperature-dependent vapor pressure characteristics selected to compensate the vapor pressure of the heat storage medium during the bakeout. There is also.

[0022] Preferably, the heat storage core comprises within the inner container:
It is supported by a support element of a heat insulating material that is resistant to a range of bakeout temperatures.

[0023] According to a further development of the invention, the inlet and outlet pipes open into the inner vessel and at both ends of the heat storage core flow channels extending through the heat storage core are opened, respectively between the inner vessel and the heat storage core. Space is kept free for the heat transfer medium.

In the heat storage core, a chamber for the heat storage medium is divided into a number of divided chamber parts, and a flow path for the heat storage medium is divided into a plurality of tubes extending between the chamber parts and the tubes. In the case of heat storage means surrounded by thin partition walls and having a shallow cross section, so that the long sides of the cross section are adjacent to each other, a further development of the invention provides:
The distance between the planar cross-sections of these adjacent chamber parts is such that these cross-sections support each other under the influence of vapor pressure and before the expansion of the walls of the chamber parts exceeds a safe threshold. can be made to lengths that enlarge the cross-section of the

In the heat storage core, the chamber for the heat storage medium is divided into a plurality of chamber sections, the flow path is divided into a plurality of tubes extending between these chamber sections, and the tubes and chamber sections are divided into a plurality of tubes extending between the chamber sections. In the case of heat storage means that are separated from each other by thin partition walls, in a further convenient development of the invention, the partition walls can be connected to each other by spacers so that forces due to vapor pressure increases and/or thermal expansion can be absorbed. . According to a further convenient development, the spacer is connected to the partition wall in a tension-transmitting manner, so that the spacer will withstand any increase in vapor pressure in the space in which it is placed.

Even more particularly, if the flow path for the heat transfer medium has a cooling medium flowing around it during bakeout, a spacer may be placed in the tube for the heat transfer medium. Even more possible. Due to the heat absorption by the coolant, the vapor pressure increases, so that the vapor pressure of the coolant also compromises the thin partition walls between the tubes and the chamber parts for the heat storage medium. The forces acting on the partition wall under the influence of vapor pressure are absorbed by the spacers as tensile forces.

According to an advantageous development of the invention, the heat storage core is surrounded by a core casing which is supported by an inner container.

[0028] In a further possible development of the invention, between the two end faces in which the tube belongs to the open flow path, the core casing comprises a face between the two ends, and an insulating gap is formed between the two end faces of the inner container. The insulating gap is formed on opposite sides of the gap and is filled with a microporous insulating material if desired. Preferably, however, the insulating gap is connected to at least one collection space to allow a flow of coolant to or from which serves to cool the heat storage core. If the insulation gap is connected to only one of the collection spaces, the coolant in the insulation gap will be placed and heated in the manner already described, preventing any cooling of the inner container. .

The invention will now be explained in more detail with reference to the accompanying drawings, which show several operative embodiments.

[0030]

[Detailed description of embodiments of the invention]

The heat storage means shown, generally referred to as 10, comprises an outer container 12 and an inner container 1 fitted with a gap across the surface.
4, which means supports an inner container 14 within an outer container 12 to constitute an insulating container, not shown. In this inner vessel 14, the heat storage core 16 is arranged in such a way that the storage zone 18 for the heat storage medium has a plurality of mutually parallel tubes 20 flowing therethrough for the heat transfer medium, the tubes 20 being connected to the core casing. 26 and appear, respectively, at two mutually distant end faces 22 and 24 of the heat storage core 16, which in this position open into collection spaces 28 and 30, respectively, for the heat transfer medium.

FIGS. 2 and 3 show two different embodiments of a heat storage core 16 surrounded by a core casing 26. FIG.

In the case of the design according to FIG. 3, the core casing surrounds a group of flat chamber parts 18a, which are parallel to each other and arranged with a gap between each other to form the tube 20, and Filled with heat storage medium.

The chamber portions 18a are defined by thin partition walls 38 separating them from the tube 20, which walls can be deformed practically without any pressure and are shown as 40 in FIG. A spacer, which is only clearly indicated, is arranged in the tube 20, which spacer is firmly connected at the enclosure wall 38 and connected to the end of the heat storage core at the core casing 26. In addition to the mechanical strength improvements discussed below, the spacer 40 functions to create turbulence in the passage of media through the flow path.

Chamber portion 18a has a flat cross-section and is generally in the form of a flat rectangle or ellipse;
The long sides of the cross sections of adjacent chamber portions 18a are opposed to each other.

The operational embodiment shown in FIG. 3 differs from the embodiment of the invention according to FIG. 2 in that a uniform chamber 18b is provided for the heat storage medium surrounded by a core casing 26. In the interior space of the chamber 18 filled with heat storage medium, the tubes 20 are spaced apart by membrane-like spacers and hoses or supports of flattened cross-sectional configuration with spaced walls 21. Ranges can be defined in the form of elements.

The flow path constituted by the collection spaces 28 and 30 of the heat storage core 16 and the tubes 20 for the heat transfer medium includes an inlet tube 32 and an outlet tube 34 leading to the inner vessel 14.
connected to. That is, as shown, the inlet pipe 3
2 leads to one collection space 28 and the outlet pipe 24 leads to the other collection station 30, or the two pipes lead to one of two collection spaces divided into an inlet and an outlet chamber and the other collection Either the station functions as a redirection chamber for the heat storage medium.

Between the two opposing end faces 22 and 24, the core has a face 35, which extends between the ends of the inner container 14, parallel to an oppositely placed face 37, with a small gap. elongated, so that an insulating gap 39 is formed between the two surfaces 35 and 37, which protects the heat storage medium 16 from overheating during bakeout.

In the modified design shown in FIG. 2, the core casing 26 and therefore also the surface 35 are opened, so that it is necessary for the insulation gap 39 to form part of the flow path for the heat transfer medium. be.

In the case of a closed design of the core casing 26, as is necessary for the modified design of the heat storage core 16 according to FIG. 3, it can also be used for the design according to FIG. The insulation gap 39 can be interrupted. However, in the case of the collection spaces 28 and 30, they may also be open because they form part of the flow path for the heat transfer medium. However, the insulation gap 39
4 and the thermal storage core 16 may be filled with a microporous material.

Between the outer container 12 and the inner container 14 is an insulating strip 36, which is evacuated and may or may not be filled with microporous material. This insulating strip 36 is traversed by an inlet tube 32 and an outlet tube 34, which terminate outside the outer container 12.

[0041] Between the core casing 26 and the inner container 14 there is a support or carrier element which is sufficiently heat resistant and preferably made of a thermally insulating material.

After the complete assembly of the heat storage means described above for permanent thermal insulation of the heat storage core 16, the above-mentioned bakeout and evacuation of the insulation strip 36 may be performed, for example, if the complete heat storage means is specified. Bakeout time, with the purpose of putting it in the oven.

For the protection of the heat storage core 16, for example, a flow path and thus also a space which constitutes an insulating space between the inside of the inner container 14 and the outside of the core casing 26 is provided.
Filled with a thermally insulating gas or a liquid such as ethylene glycol, the temperature-dependent vapor pressure change can compensate for the vapor pressure of the heat storage medium during bakeout. However, it is also possible that a thermally insulating vacuum is created in the flow path, thus requiring that inlet tube 32 and outlet tube 34 be hermetically isolated.

If the chamber section 18 is deformed by the high vapor pressure of the heat storage medium, the adjacent surrounding walls 38
However, it is possible to tolerate each other.

However, a coolant, such as a mixture of water and ethylene glycol, can likewise be circulated through the channels in order to maintain the insulation space at a temperature not exceeding the operating temperature. In this regard, the coolant is heated to a desired temperature of 120° C. prior to bakeout and evacuation so that during the initial phase of bakeout, the internal confinement or surface of the inner vessel 14 and thus the insulation strip 26 is also heated. , is heated from the inside and therefore the bakeout temperature is achieved faster. Then, if the coolant is e.g.
The thermal storage core will be protected from the damaging effects of heat if maintained by the heat to be removed at a temperature of . However, said coolant at 120° C. has a vapor pressure of 2 bars, which the enclosure wall 38 alone cannot resist. This force acting on the surrounding wall 38 is absorbed by the spacer 40 as a tensile force.

In a further possible form of the invention, not shown, the insulating gap 39 separates the collection spaces 28 and 30.
, so that flow through the insulation gap 39 is impeded while the coolant flows through the heat storage core via the tubes 20 and is maintained at the desired low temperature. but,
The coolant at rest in the insulation gap 39 is heated;
Unwanted cooling of the inner container 14 may be avoided.

A particularly economical method of manufacturing the heat storage means is to preheat the heat storage core in a preheating station, for example to the maximum permissible temperature, move the heat storage means to a bakeout station, and
Therefore, the method is to heat the insulating band to the bakeout temperature and create a vacuum.

[Brief explanation of the drawing]

FIG. 1 shows a device suitable for carrying out the measures according to the invention;
FIG. 2 is a longitudinal sectional view taken through a latent heat storage means for an automobile.

FIG. 2 is a cross-sectional view taken through a heat storage means according to a first embodiment of the invention;

FIG. 3 is a similar cross-sectional view taken through another embodiment of the invention;

FIG. 4 is a more detailed view of the structure shown in FIG. 2;

[Explanation of symbols]

12 External container 14 Inner container 16 Heat storage core 20 pipe

Claims (27)

[Claims] 1. A housing comprising an outer container and an inner container spaced apart from the outer container so as to include an insulating band therebetween, the housing being disposed within the inner container and containing a heat storage medium therein. a heat storage core comprising at least one chamber for the purpose, the chamber being separated from the at least one flow path for the heat transfer medium by a partition wall and further comprising an inlet pipe and an outlet pipe for the heat transfer medium. , the tube is connected to the flow path and extends outwardly through an insulating strip, the insulating strip being baked out and evacuated in the housing to remove gases, said baking out being connected to the heat storage means. run at temperatures substantially above operating temperature;
A method for producing a heat storage means, in particular in the form of a latent heat storage means, for a heating system of a motor vehicle working with heat from the engine, in which the components of the heat storage core are protected from any temperature-dependent damage. 2. The method of claim 1, wherein the thermal storage core is thermally insulated from the insulation strip at least during bakeout. 3. The method of claim 2, wherein the insulation strip between the thermal storage core and the inner container is filled with a gas of low thermal conductivity at least during bakeout of the insulation strip. 4. The method of claim 1, wherein the insulation strip between the thermal storage core and the inner container is evacuated at least during bakeout of the insulation strip. 5. The method of claim 1, which withstands high vapor pressures acting on the chamber containing the heat storage medium and the surrounding wall of the heat storage medium during bakeout of the insulation strip. 6. During the bakeout, a static pressure is created in the flow path of the inner container, which compensates for the high vapor pressure of the heat storage medium.
The method according to claim 5. 7. During the bakeout, the inner vessel is filled with a liquid selected such that a temperature-dependent change in its vapor pressure compensates the vapor pressure of the heat storage medium during the bakeout,
6. The method of claim 5, wherein the liquid is hermetically sealed off in the inner container during bakeout. 8. The method of claim 7, wherein during bakeout the inner container is filled with ethylene glycol. 9. The method of claim 1, wherein during bakeout, the coolant is passed through the flow path. 10. The container has an insulating gap between the inner container and a surface surrounding the heat storage core between the ends with open inlet and outlet channels, and an insulating gap between the two end surfaces. 10. The method of claim 9, wherein the path of coolant through is stopped. 11. The container has an insulating gap between the inner container and a surface surrounding the heat storage core between the ends with open inlet and outlet channels, and at the beginning of the bakeout, the coolant is transferred to the heat storage means. 10. The method of claim 9, wherein the method is heated within the operating temperature range of and maintained at that temperature during bakeout. 12. The heat storage core is first preheated to a maximum allowable temperature of the heat storage core with a liquid acting as a heat transfer medium and maintained at this temperature level until the bakeout operation is completed. Method described. 13. The method according to claim 12, wherein the evacuation of the insulation zone is started with a time lag after preheating of the heat storage core. 14. The method of claim 13, wherein the heat storage method with a preheated heat storage core is moved to a bakeout station, where the insulation strip is baked out and evacuated. 15. A housing including an outer container and an inner container spaced apart therefrom, the container defining an insulating band therebetween, and further arranged in the inner container and configured to contain a heat storage medium. a heat storage core in which at least one chamber for the heat transfer medium is separated from the at least one flow path for the heat transfer medium by a partition wall; A heat storage means adapted to carry out the method of claim 1, comprising an inlet pipe and an outlet pipe for the heat storage core, the heat storage core being supported from the inner wall of the inner container by a gap. 16. Heat storage means according to claim 15, wherein the space between the inner container and the heat storage core is in the form of a closed insulating space. 17. The heat storage means according to claim 15, wherein the space between the inner container and the heat storage core is connected to a flow path. 18. The heat storage means of claim 17, wherein the heat storage core is supported by a support element of a thermally insulating material that is generally thermally stable within the bakeout temperature range. 19. The inlet and outlet tubes lead to the inner vessel and to the outside of spaced end faces of the heat storage core, where a flow path extending outwardly through the heat storage core opens;
16. Heat storage means according to claim 15, wherein a collection space is reserved between the inner container and the heat storage core, respectively, for a heat transfer medium. 20. In the heat storage core, the chambers for the heat storage medium are separated from each other by channels for the heat transfer medium, are surrounded by partition walls and have a flattened cross section, each of which has a flattened cross section. The heat storage means is divided into a plurality of chamber parts, the main sides of the cross-section of which face each other, the distance between the flattened cross-sections of these adjacent chamber parts enlarging the cross-section of the chamber part. 15. The cross-sections are dimensioned such that, under the influence of vapor pressure tending to occur, these cross sections bear each other during bakeout before the expansion of the walls of the chamber portion exceeds a safety threshold. The heat storage means described in . 21. In the heat storage core, the chamber for the heat storage medium is divided into a plurality of chamber sections, the flow path is divided into a plurality of tubes extending between these chamber sections, and further the tube and chamber sections are divided into a plurality of tubes extending between these chamber sections. 16. Heat storage means according to claim 15, wherein are separated from each other by thin partition walls, and the partition walls are connected to each other by spacers. 22. Heat storage means according to claim 21, wherein the spacers are connected in a tension transmitting manner by a partition wall. 23. The heat storage method according to claim 21, wherein the spacer is arranged in a tube for the heat transfer medium. 24. The heat storage means of claim 15, wherein the heat storage core is enclosed within a core casing and supported by an inner container. 25. Between the two end faces, the tube belongs to an open flow path, and the core casing has a face formed opposite to the face of the inner container between which the insulating gap extends. The heat storage means according to claim 24, comprising: 26. The heat storage means according to claim 25, wherein the insulation gap is filled with a microporous insulation material. 27. The inlet and outlet tubes lead to the inner vessel and to the outside of spaced end faces of the heat storage core, where a flow path extending outwardly through the heat storage core opens;
27. Heat storage means according to claim 26, wherein a collection space is reserved for the heat transfer medium between the inner container and the heat storage core, respectively, and an insulating gap is connected to at least one of the collection spaces.