CLAIMS
1. A heat recovery and upgrading method comprising cycles of the
subsequent steps of
a. - providing a working fluid comprising a liquid phase in a working fluid
stream (11);
b. - transferring heat (20) to the working fluid stream (11) such as to partially
evaporate working fluid in liquid phase to obtain a two-phase working fluid stream (12)
in liquid phase and gas phase;
c. - compressing (30) the two-phase working fluid stream (12) so as to increase
a temperature and pressure of the working fluid and to evaporate working fluid in liquid
phase;and
d. - transferring heat (40, 60) from the working fluid stream (13, 14, 15) by
means of condensation of working fluid.
2. The method according to the preceding claim, wherein step a comprises providing the working fluid in a predominantly single-phase working fluid stream (11) in liquid phase.
3. The method according to any one of the preceding claims, wherein step c comprises compressing working fluid to evaporate working fluid in liquid phase such that a two-phase working fluid stream (13) is maintained, especially a wet gas-phase working fluid.
4. The method according to any one of the preceding claims, wherein the working fluid comprises first and second components, a boiling temperature of the second component being lower than a boiling temperature of the first component at a same pressure.
5. The method according to the preceding claim, wherein a boiling temperature of the working fluid is between boiling temperatures of the first and second components and dependent on the ratio in which the first and second components are present in the working fluid,
6. The method according to any one of the preceding two claim, wherein the first and second components are selected such as to provide a non-separating mixture.

7. The method according to any one of the preceding three claims, wherein the first and second components are alkali ionized components when mixed together.
8. The method according to any one of the preceding four claims, wherein the first component is water and the second component is ammonia.
9. The method according to any one of the preceding claims, wherein in step b heat is collected from a first medium and transferred (20) to the working fluid stream (11).

10. The method according to any one of the preceding claims, wherein in step d heat is transferred (40, 60) to a second medium.
11. The method according to any one of the preceding claims, wherein at least part of the liquid phase of the two-phase working fluid stream (12) is provided as droplets in step c before and/or during compression (30) of the working fluid stream.
12. The method according to any one of the preceding claims, wherein at least part of the liquid phase of the two-phase working fluid stream (12) is separated from the two-phase working fluid stream and provided as droplets in step c before or during compression (30) of the working fluid stream.
13. The method according to any one of the preceding two claims, wherein the droplets are provided at an inlet of and/or in a compression chamber of a compressor (30) for compression of the working fluid.
14. The method according to any one the preceding three claims, wherein the liquid phase of the two-phase working fluid stream (12) is provided as a spray of tiny droplets.
15. The method according to any one of the preceding claims, wherein the method comprises subsequent to step c the step of
- expansion (50) of the working fluid steam (13, 14).
16. The method according to the preceding claim, wherein power is
recovered from expansion (50) of the working fluid.

17. The method according to any one of the preceding two claims, wherein the working fluid is expanded in a positive displacement expander orturbine (50),
18. A compressor for use in step c of the method according to any one of the preceding claims, wherein the compressor is configured for compressing a two-phase working fluid so as to increase a temperature and pressure of the working fluid and to evaporate working fluid in liquid phase.
19. The compressor according the preceding claim, wherein the compressor comprises a distribution arrangement configured for providing at least part of the liquid phase of the two-phase working fluid stream (12) as droplets in the compressor.
20. The compressor according to any one of the preceding two claims, wherein the compressor comprises a separation arrangement configured for separating at least part of the liquid phase of the two-phase working fluid stream (12) from the two-phase working fluid stream and a distribution arrangement configured for providing the separated liquid phase as droplets in the compressor.
21. The compressor according to any one of the preceding t/vo claims, wherein the distribution arrangement is configured for providing droplets at an inlet of and/or in a compression chamber of the compressor (30).
22. The compressor according to any one of the preceding three claims, wherein the distribution arrangement is configured to provide the liquid phase of the two-phase working fluid stream (12) as a spray of tiny droplets.