Latent heat storage device and associated manufacturing method

1. A latent heat storage device for an exhaust system of a combustion engine, comprising:

a housing that defines at least one hollow space, the at least one hollow space having a constant storage volume;

a phase changing material contained within the at least one hollow space, the phase changing material having a first volume when in a solid state and a second volume larger than the first volume when in a molten state; and

wherein the constant storage volume that is so dimensioned so as to consist of a basic volume corresponding to the first volume of the phase-changing material and an expansion volume corresponding to an increase in volume from the first volume to the second volume.

2. The latent heat storage device according to claim 1 , wherein the latent heat storage device has a predetermined maximum operating temperature; and

wherein the expansion volume is sized to receive a melt expansion of the phase-changing material and a temperature expansion of the phase-changing material at the predetermined maximum operating temperature of the latent heat storage device.

3. The latent heat storage device according to claim 1 , wherein the latent heat storage device has a predetermined maximum operating temperature; and

wherein the expansion volume accommodates a maximum operating pressure which the phase-changing material generates in the molten state at the predetermined maximum operating temperature of the latent heat storage device.

4. The latent heat storage device according to claim 1 , wherein the at least one hollow space is sealed to form a vacuum therein.

5. The latent heat storage device according to claim 4 ,

wherein the expansion volume is so dimensioned such that with the phase-changing material in a solid state the vacuum is obtained, and such that with the phase-changing material in the molten state a predetermined operating pressure is formed.

6. The latent heat storage device according to claim 5 ,

wherein the predetermined operating pressure is formed at a predetermined operating temperature range of the latent heat storage device.

7. The latent heat storage device according to claim 1 , wherein the at least one hollow space is so configured to allow the phase-changing material upon solidification to be disposed in spatially distributed microzones, such that the basic volume and the expansion volume of the solidified phase-changing material are intermixed.

8. The latent heat storage device according to claim 7 , wherein upon solidification of the phase changing material the respective hollow space comprises a capillary structure creating the spatially distributed microzones.

9. The latent heat storage device according to claim 7 , wherein the respective hollow space consists of a plurality of hollow sub-spaces, which are connected with one another in a communicating manner via one of redirecting points and narrow points.

10. The latent heat storage device according to claim 7 , wherein the respective hollow space on its walls comprises a surface structure that improves the wetting with the phase-changing material in the liquid state.

11. The latent heat storage device according to claim 7 , wherein the respective hollow space comprises a spatial structure; and wherein the phase-changing material in the liquid state has a sponge-like effect.

12. A method for the filling of a latent heat storage device for an exhaust system of a combustion engine, comprising:

providing a phase-changing material that in a first state is solid and in a second state is molten;

providing a housing to define at least one hollow space having a constant storage volume, the storage volume configured to contain the phase-changing material, wherein the constant storage volume is so dimensioned so as to consist of a basic volume, which the phase-changing material fills in the first state, and an expansion volume, which the phase-changing material additionally fills in the second state,

filling the basic volume of the at least one hollow space with the phase-changing material in the first state as one of bulk or as at least one shaped body;

creating a vacuum in the at least one hollow space; and

sealing the at least one hollow space.

13. A method for the filling of a latent heat storage device for an exhaust system of a combustion engine, comprising:

selecting a phase-changing material that in a first state is solidified and is transitionable into a second molten state;

fixing a housing to surround at least one hollow space having a constant storage volume;

wherein the constant storage volume is so dimensioned so as to consist of a basic volume of the phase-changing material in a solidified state and an expansion volume for a molten state of the phase changing material;

filling the basic volume of the at least one hollow space with the phase-changing material in the solidified state as one of bulk or as at least one shaped body;

melting the phase-changing material within the at least one hollow space; and sealing the at least one hollow space.

14. A method for the filling of a latent heat storage device for an exhaust system of a combustion engine, comprising:

selecting a phase-changing material that in a first state is solidified and is transitionable into a second molten state;

fixing a housing to surround at least one hollow space, the at least one hollow space having a constant storage volume;

wherein the constant storage volume is so dimensioned so as to consist of a basic volume of the phase-changing material and an expansion volume for the molten state of the phase changing material;

filling the basic volume of the at least one hollow space with the phase-changing material in the liquid state; and

sealing the at least one hollow space.