Modified two-phase refrigeration cycle
A modified two-phase refrigeration cycle compresses a working fluid, condenses the working fluid into a saturated or supercooled liquid, expands the saturated or supercooled liquid into a two-phase fluid, and evaporates the two-phase working fluid. The modified two-phase refrigeration cycle reduces irreversibilities imposed by conventional refrigeration cycles and extracts energy from the working fluid during the expansion process. For instance, a system that employs the modified two-phase refrigeration cycle includes a two-phase expander to reduce irreversibilities during an expansion process and extract energy. In some instances, the system includes a two-phase compressor to compress two-phase fluids for varying loads and environmental conditions of the system.
1. A system, comprising:
an evaporator;
a two-phase compressor coupled to the evaporator, wherein the two-phase compressor is configured to receive a low-pressure two-phase fluid from the evaporator and compress the low-pressure two-phase fluid into a high-pressure two-phase fluid;
a condenser coupled to the two-phase compressor; and
a two-phase expander directly coupled to the condenser and the evaporator, wherein the two-phase expander is configured to receive the high-pressure two-phase fluid from the condenser and expand the high-pressure two-phase fluid into the low-pressure two-phase fluid.
2. The system of claim 1 , wherein the two-phase expander includes:
a rotor;
vanes engaged with the rotor; and
a plurality of chambers separated by the vanes,
wherein the plurality of chambers is configured to receive the high-pressure two-phase fluid and expands the high-pressure two-phase fluid into the low-pressure two-phase fluid.
3. The system of claim 1 , wherein at least one of:
the two-phase expander is a positive-displacement expander;
the two-phase compressor is a positive-displacement compressor;
the two-phase expander is a radial-flow expander; or
the two-phase compressor is a centrifugal compressor.
4. The system of claim 1 , further comprising a generator coupled to the two-phase expander to generate electricity from movement of the two-phase expander.
5. The system of claim 1 , wherein the two-phase compressor includes:
a shaft;
a rotor coupled to the shaft; and
a plurality of vanes that travel in a direction parallel to the shaft.
6. The system of claim 1 , wherein at least one of:
the two-phase compressor is further configured to compress the low-pressure two-phase fluid into a high-pressure superheated vapor; or
the expander is configured to receive a high-pressure saturated or supercooled liquid fluid and expand the high-pressure saturated or supercooled liquid into the low-pressure two-phase fluid.
7. The system of claim 1 , wherein the two-phase compressor is further configured to compress the low-pressure two-phase fluid into at least one of:
the high-pressure two-phase working fluid; or
a high-pressure superheated vapor.
8. A system, comprising:
an evaporator;
a two-phase compressor coupled to the evaporator;
a condenser coupled to the compressor; and
a two-phase expander directly coupled to the condenser and the evaporator, wherein the two-phase expander is configured to receive a high-pressure two-phase working fluid from the condenser and expand the high-pressure two-phase working fluid into a low-pressure two-phase working fluid.
9. The system of claim 8 , wherein the high-pressure two-phase working fluid received by the two-phase expander from the condenser has a liquid quality of at least 95 percent.
10. The system of claim 8 , wherein the two-phase compressor is configured to receive the low-pressure two-phase working fluid from the evaporator and compress the low-pressure two-phase working fluid into the high-pressure two-phase working fluid.
11. The system of claim 8 , further comprising a compressor coupled to the two-phase compressor and the evaporator, wherein:
the two-phase compressor is disposed between the compressor and the evaporator; and
the two-phase compressor is configured to pre-compress the low-pressure two-phase working fluid.
12. The system of claim 11 , wherein the two-phase expander operably couples to at least one of the compressor or the two-phase compressor to at least partially power the at least one of the compressor or the two-phase compressor.
13. The system of claim 8 , further comprising a generator coupled to the two-phase expander to generate electricity from movement of the two-phase expander.
14. The system of claim 8 , wherein:
the two-phase compressor is disposed between the evaporator and the condenser; and
the two-phase compressor is configured to compress the low-pressure two-phase working fluid from the evaporator into the high-pressure two-phase working fluid.
15. The system of claim 8 , wherein the two-phase compressor is configured to receive the low-pressure two-phase working fluid from the evaporator and compress the low-pressure two-phase working fluid into at least one of:
a high-pressure superheated vapor; or
a high-pressure saturated vapor.
16. A method, comprising:
compressing, in a two-phase compressor, a low-pressure two-phase working fluid into a high-pressure two-phase working fluid;
condensing, in a condenser, the high-pressure two-phase working fluid;
expanding, in an expander, the high-pressure two-phase working fluid from the condenser into the low-pressure two-phase working fluid; and
evaporating the low-pressure two-phase working fluid.
17. The method of claim 16 , further comprising generating, via a movement of the expander expanding the high-pressure two-phase working fluid, power using a generator operably coupled to the expander.
18. The method of claim 16 , wherein the expander is a positive-displacement expander.
19. The method of claim 16 , wherein the low-pressure two-phase working fluid output from the expander has a liquid quality of at least 75 percent.