Electrodialysis heat pump
A system includes an electrochemical regenerator configured to receive a first solution having a first salt concentration and output a second solution having a second salt concentration lower than the first salt concentration and a third solution having a third salt concentration higher than the first salt concentration. The first and second solutions are sent to first and second reservoirs respectively absorb and emit heat in response to a phase change of one of the solutions. The absorption or emission of heat can be used in a heat pump system.
1. A system comprising:
an electrochemical regenerator configured to receive a first solution having a first salt concentration and to output a second solution having a second salt concentration lower than the first salt concentration and a third solution having a third salt concentration higher than the first salt concentration;
a first reservoir with first contents having a first water vapor pressure and configured to receive the second solution and output a vapor stream and a residual stream, the first reservoir absorbing a first heat flux;
a second reservoir with second contents having a second water vapor pressure that is less than the first water vapor pressure and coupled to the first reservoir, wherein the second reservoir is configured to receive the third solution and the vapor stream from the first reservoir to generate a second heat flux that is output from the second reservoir, a recombined solution comprising contents of the second reservoir and the residual stream being recirculated to the electrochemical regenerator; and
a secondary heat pump with a working fluid that is cooled by the first heat flux.
2. A system comprising:
an electrochemical regenerator configured to receive a first solution having a first salt concentration and to output a second solution having a second salt concentration lower than the first salt concentration and a third solution having a third salt concentration higher than the first salt concentration;
a first reservoir with first contents having a first water vapor pressure and configured to receive the second solution and output a vapor stream and a residual stream, the first reservoir absorbing a first heat flux;
a second reservoir with second contents having a second water vapor pressure that is less than the first water vapor pressure and coupled to the first reservoir, wherein the second reservoir is configured to receive the third solution and the vapor stream from the first reservoir to generate a second heat flux that is output from the second reservoir, a recombined solution comprising contents of the second reservoir and the residual stream being recirculated to the electrochemical regenerator; and
a thermal target that is heated by the second heat flux.
3. The system of claim 2 , wherein the thermal target comprises a secondary heat pump with a working fluid that is heated by the second heat flux.
4. The system of claim 2 , wherein the third solution is combined with the vapor stream in a first stage of the second reservoir and contents of the first stage are combined with the residual stream in a second, separate stage of the second reservoir.
5. The system of claim 2 , wherein the thermal target comprises a water heater.
6. The system of claim 2 , wherein a fourth salt concentration of the recombined solution is approximately equal to the first salt concentration.
7. The system of claim 2 , wherein the second salt concentration is above 5% by weight.
8. The system of claim 2 , further comprising one or more storage reservoirs to hold respective one or more of the first solution, the second solution, the third solution, and the recombined solution.
9. The system of claim 8 , wherein the one or more storage reservoirs are used for load shifting and sharing between two or more of the electrochemical regenerator, the first reservoir, and the second reservoir.
10. The system of claim 2 , further comprising:
a burner that converts a combustible fuel to heat; and
a solid-state heat-to-electricity converter that converts a first portion of the heat to electricity that powers the electrochemical regenerator, a second portion of the heat being high-temperature waste heat that is combined with the second heat flux at the thermal target.
11. The system of claim 10 , wherein the high-temperature waste heat is coupled to heat the first reservoir to cause evaporation of the vapor stream.
12. A method comprising:
producing a low salinity solution and a high salinity solution from an electrochemical regenerator;
directing the low salinity solution to a first reservoir with first contents having a first water vapor pressure, the first reservoir outputting a vapor stream and a residual stream and absorbing a first heat flux;
directing the high salinity solution and the vapor stream to a second reservoir having a second water vapor pressure that is less than the first water vapor pressure, the second reservoir outputting a second heat flux and a recombined solution, the recombined solution comprising contents of the second reservoir and the vapor stream; and
using one or both of the first heat flux and the second heat flux as a respective heat sink and heat source in a heat pump system.
13. The method of claim 12 , further comprising performing one of cooling or heating of a working fluid of a heat pump respectively by the first heat flux or the second heat flux.
14. The method of claim 12 , further comprising:
storing one or more of the low salinity solution, the high salinity solution, and the recombined solution in one or more respective storage reservoirs; and
using the one or more storage reservoirs for load shifting and sharing between two or more of the electrochemical regenerator, the first reservoir, and the second reservoir.
15. The method of claim 12 , further comprising:
converting a combustible fuel to heat;
converting a first portion of the heat to electricity via a solid state converter that is used to power the electrochemical regenerator; and
performing at least one of combining a second portion of the heat with the second heat flux and heating the first reservoir with the second portion of the heat to cause evaporation of the vapor stream.
16. The method of claim 12 , further comprising:
combining the high salinity solution with the vapor stream in a first stage of the second reservoir; and
combining contents of the first stage with the residual stream in a second, separate stage of the second reservoir.
17. The method of claim 12 , wherein the low salinity solution has a salt concentration above 5% by weight.