Heat-pump driven desiccant regeneration

Patent metadata

Field	Value
Publication number	US-11029045-B2
Application number	US-201916353335-A
Country	US
Kind code	B2
Filing date	Mar 14, 2019
Priority date	Mar 16, 2018
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

Disclosed herein are systems and processes to thermally regenerate and re-concentrate a liquid desiccant (absorbent) with an electrically driven heat pump. The regeneration and re-concentration may be performed in a cost and energy efficient manner.

First claim

The invention claimed is:

1. A method comprising:
removing a moisture from a first air stream using a desiccant to absorb the moisture;
operating a heat pump comprising a refrigerant stream circulating through an evaporator, a compressor, a valve, and a condenser;
routing the desiccant that is diluted with the moisture through the condenser to heat the desiccant and evaporate the moisture;
collecting the evaporated moisture using a second air stream also routed through the condenser; and
depositing the evaporated moisture in the evaporator by routing the second air stream through the evaporator.

2. The method of claim 1 , further comprising cooling the first air stream using evaporative cooling.

3. The method of claim 2 , wherein the evaporated moisture collected in the evaporator is used to provide the evaporative cooling.

4. The method of claim 1 , wherein:
the second air stream is routed through an air-to-refrigerant heat exchanger prior to entering the condenser, and
the refrigerant is routed through the air-to-refrigerant heat exchanger after exiting the condenser.

5. The method of claim 1 , wherein the second air stream is routed through an air-to-air heat exchanger after exiting the condenser but prior to entering the evaporator.

6. The method of claim 5 , wherein the second air stream is routed through the air-to-air heat exchanger prior to entering the condenser.

7. The method of claim 5 , wherein the second air stream is routed through the air-to-air heat exchanger after exiting the evaporator.

8. The method of claim 1 , further comprising:
splitting the refrigerant stream exiting the compressor into a first refrigerant stream and a second refrigerant stream using a three-way valve;
routing the first refrigerant stream through the condenser;
routing the second refrigerant stream and the first air stream through a first air-to-refrigerant heat exchanger;
combining the first refrigerant stream and the second refrigerant stream into a unified refrigerant stream;
routing the unified refrigerant stream through a second air-to-refrigerant heat exchanger; and
routing the second air stream through the second air-to-refrigerant heat exchanger prior to entering the condenser.

9. The method of claim 8 , wherein the first air stream is heated by the first air-to-refrigerant heat exchanger.

10. The method of claim 1 , wherein:
the refrigerant stream bypasses the condenser,
the refrigerant stream is used to heat a secondary fluid in a refrigerant-to-secondary fluid heat exchanger, and
the secondary fluid is routed through the condenser.

11. The method of claim 10 , wherein the secondary fluid is water.

12. The method of claim 10 , wherein:
the refrigerant is routed through an air-to-refrigerant heat exchanger after exiting the refrigerant-to-secondary fluid heat exchanger, and
the second air stream passes through the air-to-refrigerant heat exchanger prior to entering the condenser.

13. The method of claim 1 , wherein the operation of the heat pump occurs when a majority of the desiccant is diluted with the moisture.

14. The method of claim 1 , further comprising storing the desiccant and the moisture in a tank.

15. The method of claim 14 , wherein the tank contains a device configured to measure the volume of the desiccant and the moisture in the tank.

16. The method of claim 15 , wherein the heat pump is operated when the volume of the desiccant and the moisture in the tank reaches a pre-determined level.

17. The method of claim 1 , wherein the heat pump is operated until a majority of the desiccant is not diluted with the moisture.

Assignees

• Alliance Sustainable Energy

Inventors

• Woods Jason David
• Kozubal Eric

Classifications

• F24F2203/021

  Compression cycle · CPC title

• F24F2003/1458

  using regenerators · CPC title

• F24F3/1417 Primary

  with liquid hygroscopic desiccants · CPC title

• Y02B30/52

  Heat recovery pumps, i.e. heat pump based systems or units able to transfer the thermal energy from one area of the premises or part of the facilities to a different one, improving the overall efficiency · CPC title

• B01D53/263

  by absorption · CPC title