Heat transfer and storage system

• US 4,727,930 A
• Filed: 08/17/1981
• Issued: 03/01/1988
• Est. Priority Date: 08/17/1981
• Status: Expired due to Term

• Current Assignee: Board of Regents of The University of Washington (University of Washington)
• Original Assignee: Board of Regents of The University of Washington (University of Washington)
• Inventors: Shaw, David J., Bruckner, Adam P., Hertzberg, Abraham
• Primary Examiner(s): Davis, Jr., Albert W.
• Application Number:
  US06/293,196
• Time in Patent Office: 2,388 Days
• Field of Search: 165/111, 165/104.17, 165/1, 165/84
• US Class Current: 165/111
• CPC Class Codes: F02C 1/05 characterised by the type or source of heat, e.g. using nuclear or solar energy
• CPC Class Codes: F02C 1/10 Closed cycles
• CPC Class Codes: F02C 6/14 Gas-turbine plants having means for storing energy, e.g. for meeting peak loads
• CPC Class Codes: F03G 6/064 having a gas turbine cycle, i.e. compressor and gas turbine combination
• CPC Class Codes: F24S 20/20 Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants
• CPC Class Codes: F24S 80/20 Working fluids specially adapted for solar heat collectors
• CPC Class Codes: F28C 3/14 the particulate material moving by gravity, e.g. down a tube
• CPC Class Codes: F28D 20/0056 using solid heat storage material F28D20/0052 takes precedence
• CPC Class Codes: F28D 2020/006 Heat storage systems not otherwise provided for
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02E 10/46 Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines
• CPC Class Codes: Y02E 60/14 Thermal energy storage
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

An energy storage and conversion system utilizes unique heat exchange media for storing and transferring heat. In one embodiment, a refractory material is heated to the molten state by a solar furnace. The refractory material is stored in its molten form and metered to a direct-contact heat exchanger. It is fed into the heat exchanger in a plurality of streams that break into a plurality of droplets. The droplets flow through the heat exchanger in countercurrent relationship with a relatively inert gas such as argon or nitrogen. The gas is heated and expanded through an expansion engine to convert the thermal energy to mechanical energy which in turn can be utilized to produce electricity, for example. The refractory can be sufficiently cooled in the heat exchanger to fuse into beads, which can be easily recycled to the solar furnace.

Claims

1. A method for exchanging heat between a first liquid heat exchange medium and a second gaseous heat exchange medium that is immiscible with and substantially insoluble in said first medium comprising:

causing the first heat exchange medium to traverse a heat transfer zone in the form of droplets, said first heat exchange medium being injected into said heat transfer zone as a plurality of relatively small diameter liquid streams, the liquid streams being sized and the first heat exchange medium being selected to cause each of the streams to break into a plurality of droplets of substantially uniform size as they enter the heat transfer zone, said liquid streams further being externally mechanically excited to produce said droplets of substantially uniform size, and

causing the second heat exchange medium to traverse the heat transfer zone in countercurrent flow relationship to said first heat exchange medium and allowing the heat exchange medium to make intimate thermal contact with each other.

2. The method of claim 1 further comprising:

allowing said first heat exchange medium to be cooled to a solid in said heat transfer zone.

3. The method of claims 1 or 2 wherein said second heat exchange medium is gaseous.

4. The method of claim 3 wherein said first and second heat exchange media are substantially inert relative to each other.

5. The method of claim 3 wherein said first heat exchange medium is a refractory oxide.

6. The method of claim 5 wherein said first heat exchange medium is selected from the group consisting of alumina, lime, chromic oxide, magnesia, silica, soda, lithia, zirconia, and mixtures thereof.

7. The method of claim 1 wherein said first heat exchange medium is injected into said heat transfer zone in a plurality of liquid streams sized to cause said first heat exchange medium in each of said streams to break into a plurality of droplets of substantially uniform size.