Solid-State Compressor and Method for Providing Counter Pressure on a Solid-State Compressor Cell Stack

Abstract

The invention relates to a solid-state compressor for electrochemically compressing a fluid, including: a compressor cell stack, including at least one compressor cell having a membrane electrode assembly sandwiched between two cell plates, an enclosure, clamping the compressor cell stack at opposing sides thereof, and at least one contact body, interposed between the compressor cell stack and the enclosure and contacting an outer surface of the compressor cell stack, wherein a space is enclosed between the enclosure and the contact body, which space is configured to contain a hydraulic fluid under pressure. The invention further relates to a method for operating such a solid-state compressor.

Claims

1. A solid-state compressor for electrochemically compressing a fluid, comprising: a compressor cell stack, comprising at least one compressor cell having a membrane electrode assembly sandwiched between two cell plates, an enclosure, clamping the compressor cell stack at opposing sides thereof, and at least one contact body, interposed between the compressor cell stack and the enclosure and contacting an outer surface of the compressor cell stack, wherein a space is enclosed between the enclosure and the contact body, which space is configured to contain a hydraulic fluid under pressure.

2. The solid-state compressor according to claim 1, wherein the solid-state compressor comprises a pressure adjustment mechanism configured for adjusting the pressure of the hydraulic fluid contained in the space.

3. The solid-state compressor according to claim 2, wherein the pressure adjustment mechanism is configured to adjust the hydraulic fluid pressure based on a pressure prevailing on a cathode side of the at least one membrane electrode assembly.

4. The solid-state compressor according to claim 3, wherein the pressure adjustment mechanism is configured for keeping a fixed ratio between the pressure prevailing on the cathode side of the at least one membrane electrode assembly and the hydraulic fluid pressure.

5. The solid-state compressor according to claim 4, wherein the hydraulic fluid pressure is larger, preferably between 1.1 times and 2.5 times larger, and more preferably 2 times larger than the pressure prevailing on the cathode side of the at least one membrane electrode assembly.

6. The solid-state compressor according to claim 1, wherein the space is hydraulically linked with a hydraulic fluid reservoir.

7. The solid-state compressor according to claim 6, wherein the reservoir has a variable volume, wherein the pressure adjustment mechanism is configured for adjusting the volume of the hydraulic fluid reservoir.

8. The solid-state compressor according to claim 7, wherein the pressure adjustment mechanism comprises a displacer piston, comprising a first piston head surface standing in contact with the hydraulic fluid reservoir, for changing the volume of the hydraulic fluid reservoir upon displacement of the piston head.

9. The solid-state compressor according to claim 8, wherein the displacer piston comprises a second piston head surface opposing the first piston head surface, which second piston head surface stands in contact with a pressurized fluid reservoir for changing the volume of the pressurized fluid reservoir upon displacement of the piston head.

10. The solid-state compressor according to claim 9, wherein the cathode side of the at least one membrane electrode assembly is linked with the pressurized fluid reservoir.

11. The solid-state compressor according to claim 9, wherein the areas of the first and second piston head surfaces mutually differs.

12. The solid-state compressor according to claim 1, wherein the solid-state compressor comprises two contact bodies, each interposed between the enclosure and a different one of two opposing sides of the compressor cell stack, wherein a space is enclosed between the enclosure and the respective contact bodies, which spaces are configured to contain a hydraulic fluid under pressure.

13. The solid-state compressor according to claim 12, wherein the contact bodies are moveably embedded within the enclosure such that the volume of the spaces between the enclosure and the respective contact bodies changes upon a movement of the contact bodies relative to the enclosure.

14. The solid-state compressor according to claim 12, wherein the spaces between the enclosure and the respective contact bodies are hydraulically linked with each other.

15. The solid-state compressor according to claim 12, wherein the enclosure comprises two opposing and interconnected flanges that respectively grip around each of the contact bodies, thereby entirely enclosing a surface of said contact bodies opposing the surface contacting an outer surface of the compressor cell stack.

16. The solid-state compressor according to claim 15, wherein the opposing flanges are mutually connected through a connection pre-loaded in tension, which preload urges the opposing flanges towards each other such that the hydraulic fluid contained in the spaces is compressed.

17. The solid-state compressor according to claim 15, wherein the opposing flanges are interconnected by at least one bolted joint.

18. The solid-state compressor according to claim 17, wherein one or more Belleville washers are positioned between at least one of the flanges and a bolt head or nut of the bolted joint.

19. An assembly of an enclosure and at least one contact body for a solid-state compressor according to claim 1.

20. A pressure adjustment mechanism for adjusting the pressure in a hydraulic fluid contained within a space enclosed between an enclosure and a contact body of a solid-state compressor according to claim 1.

21. A method for operating a solid-state compressor according to claim 1, comprising introducing a hydraulic fluid under pressure in the space between the enclosure and the contact body.

22. The method according to claim 21, wherein the method further comprises adjusting the pressure in the hydraulic fluid.

23. The method according to claim 22, wherein the pressure in the hydraulic fluid is adjusted based on the pressure prevailing on a cathode side of the at least one membrane electrode assembly.

24. The method according to claim 23, wherein a fixed ratio is kept between the pressure prevailing on the cathode side of the at least one membrane electrode assembly and the pressure in the hydraulic fluid.

25. The method according to claim 24, wherein the pressure in the hydraulic fluid is kept larger, preferably between 1.1 times and 2.5 times larger, and more preferably 2 times larger than the pressure prevailing on the cathode side of the at least one membrane electrode assembly.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to further elucidate the invention, exemplary, non-limitative embodiments will be described with reference to the figures. In the figures:

[0037] FIG. 1 shows a perspective view on a solid-state compressor according to the invention,

[0038] FIG. 2 shows an exploded view on the solid-state compressor of FIG. 1, and

[0039] FIG. 3 shows a schematic sectional view of a solid-state compressor according to the invention.

[0040] The figures represent specific exemplary embodiments of the invention and should not be considered limiting the invention in any way or form. Throughout the description and the figures corresponding reference numerals are used for corresponding elements.

DESCRIPTION OF THE INVENTION

[0041] FIGS. 1 and 2 respectively show a perspective view and an exploded view on a solid-state compressor 1 according to the invention. The solid-state compressor 1 comprises a compressor cell stack 2 comprising multiple membrane electrode assemblies 3 sandwiched between cell plates 4. The outermost plates 5 of each cell stack 2 are commonly formed by current collector plates to act as a pass-through for electrically connecting the electrodes to a power source. The compressor cell stack 2 is at opposing sides clamped between an enclosure 6 that keeps a pressure onto the cell stack 2. The shown enclosure 6 comprises two flanges 7 that are interconnected near their peripheral edges by an array of bolted joints formed by bolts 8 and nuts 9. Interposed between opposing outer surfaces 10 of the cell stack 2 and the enclosure 6 are two contact bodies 11 that stand in contact with said outer surfaces 10. As can be seen in the hereafter discussed FIG. 3, a space is enclosed between each of the flanges 7 and contact bodies 11, which space contains a pressurized hydraulic fluid. In order to supply hydraulic fluid to or retract hydraulic fluid from this space, the contact bodies 11 are on their sides provided with hydraulic fluid supply openings 12.

[0042] FIG. 3 shows a schematic sectional view of a solid-state compressor 20 according to the invention. Again, a compressor cell stack 21 is shown, of which two opposing outer surfaces 22 are clamped between two contact bodies 23. The combination of cell stack 21 and contact bodies 23 is enclosed by an enclosure 24, comprising two opposing flanges 25 interconnected by means of bolted joints 26. The flanges 25 hereby grip around each of the contact bodies 23, fully enclosing the surfaces of the contact bodies opposing the surfaces contacting the outer surfaces 22 of the cell stack 21. Between the flanges 25 and the contact bodies 23, spaces 27 are enclosed, which contain a pressurized hydraulic fluid 28. Seals 29 are provided between the sides of the flanges 25 and the contact bodies 23 in order to obtain a closed-off volume able to contain the pressurized hydraulic fluid 28. The upper one of the spaces 27 is hydraulically connected to a hydraulic fluid reservoir 30 by means of a hydraulic fluid line 31. The lower one of the spaces 27 is in this depicted embodiment of the solid-state compressor not hydraulically linked to a hydraulic fluid reservoir, nor hydraulically linked to the upper space. As such, a passive pressure compensation system is obtained on the lower side of the solid-state compressor 20. Last mentioned variations however lie within the scope of the invention.

[0043] The volume of the hydraulic fluid reservoir 30 is variable through a pressure adjustment mechanism 32 comprising a displacer piston 33. The displacer piston 33 is moveable within the piston housing 34 and comprises a first piston head surface 35 that stands in direct contact with the hydraulic fluid 28 contained in the hydraulic fluid reservoir 30. The displacer piston further comprises a second piston head surface 36 opposing the first piston head surface 35, which second piston head surface 36 stands in direct contact with a pressurized fluid 37 contained within a pressurized fluid reservoir 38. Given that the first and second piston head surfaces 35,36 are part of the same piston, they will perform a concurrent movement thereby balancing the pressures in the pressurized fluid and hydraulic fluid reservoir 30,38. The ratio between the pressures in both reservoirs is hereby dependent on the surface areas of the piston head surfaces 35,36. The pressurized fluid reservoir 38 is connected to the cathode side of the membrane electrode assemblies contained in the cell stack 21 via a pressurized fluid line 39. The pressurized fluid 37 contained in the pressurized fluid reservoir 38 is therefore the same as the working fluid of the compressor 20.