US20120180988A1 - Moving thermal bed to time shift liquifaction and vaporization - Google Patents

Abstract

A method to store and utilize thermal energy is provided. During a first phase, transferring heat from the heat relocation media to the lower temperature reservoir, transferring heat from the higher temperature stream to the heat relocation media, and transferring heat from the heat relocation media to the high temperature reservoir, thereby at least partially liquefying the higher temperature stream. During a second phase, transferring heat from the higher temperature reserve to the heat relocation media, transferring heat from the heat relocation media to the lower temperature stream, and transferring heat from the heat relocation media to the lower temperature reservoir, thereby at least partially vaporizing the lower temperature stream.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• This application claims the benefit under 35 U.S.C. §119(e) to provisional application No. 61/434,088, filed Jan. 19, 2011, the entire contents of which are incorporated herein by reference.
BACKGROUND
• Currently, when a cycle contains vaporization and liquefaction, they are simultaneous and dependent upon one another. The present invention allows a liquefier to operate for a period of time, typically around 12 to 24 hours and store liquid product during times when power is plentiful and cheap-. This liquid would then be re-vaporized during times when power is expensive and possibly used to expand through a generator to return the stored power to the grid. The proposed invention provides a way to store thermal energy at the warm and cold end liquefier temperatures, and provides a means of providing an efficient thermal liquefaction and re-vaporization profile at these different times.
SUMMARY
• A method to store and utilize thermal energy is provided. This method includes providing a heat relocation media. Also providing a higher temperature stream and a lower temperature stream, providing a heat transfer means between the higher temperature stream and the heat relocation media, and providing a heat transfer means between the lower temperature stream and the heat relocation media. Also providing a higher temperature reservoir and a lower temperature reservoir, providing a heat transfer means between the heat relocation media and the higher temperature reservoir, and providing a heat transfer means between the heat relocation media and the lower temperature reservoir. During a first phase, transferring heat from the heat relocation media to the lower temperature reservoir, transferring heat from the higher temperature stream to the heat relocation media, and transferring heat from the heat relocation media to the high temperature reservoir, thereby at least partially liquefying the higher temperature stream. During a second phase, transferring heat from the higher temperature reserve to the heat relocation media, transferring heat from the heat relocation media to the lower temperature stream, and transferring heat from the heat relocation media to the lower temperature reservoir, thereby at least partially vaporizing the lower temperature stream
BRIEF DESCRIPTION OF DRAWINGS
• The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, and in which:
• FIG. 1 illustrates a first phase of operation, in accordance with one embodiment of the present invention.
• FIG. 2 illustrates a second phase of operation, in accordance with another embodiment of the present invention.
• FIG. 3 illustrates a gravity feed scheme, in accordance with another embodiment of the present invention.
• FIG. 4 illustrates an auger fed scheme, in accordance with another embodiment of the present invention.
• FIG. 5 illustrates a first phase of operation, in accordance with one embodiment of the present invention.
• FIG. 6 illustrates a second phase of operation, in accordance with another embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
• Illustrative embodiments of the invention are described below. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
• It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
• Turning toFIGS. 1 and 2, which in the interest of clarity retains the same element numbers, which illustrates one embodiment of the present invention, alower temperature reservoir101, and ahigher temperature reservoir102 are provided.Lower temperature stream109 is thermodynamically linked Q2 tolower temperature reservoir101 by means offirst heat exchanger103.Higher temperature stream105 is thermodynamically linked Q1 tohigher temperature reservoir102 by means ofsecond heat exchanger104.
• FIG. 1 illustrates a first phase of operation. During this first phase,higher temperature stream105 is introduced intosecond heat exchanger104.
• Lower temperature reservoir101, which in this case acts as a cold source, providingcold stream107.Cold stream107 is introduced intosecond heat exchanger104, wherein it exchanges heat indirectly Q1 withhigher temperature stream105, thereby producing acooler stream106, and awarmer stream108.Warmer stream108 is then introduced intohigh temperature reservoir102.Cooler stream106 may be at least partially liquefied.Higher temperature stream105 may be essentially pure oxygen, essentially pure nitrogen or air.
• FIG. 2 illustrates a second phase of operation. During this second phase,lower temperature stream109 is introduced intofirst heat exchanger103.Higher temperature reservoir102, which in this case acts as a heat source, providinghot stream111.Hot stream111 is introduced intofirst heat exchanger103, wherein it exchanges heat indirectly Q2 withlower temperature stream109, thereby producing awarmer stream110, and acooler stream112. Coolerstream112 is then introduced intolow temperature reservoir101.Warmer stream110 may be at least partially vaporized.Lower temperature stream109 may be essentially pure oxygen, essentially pure nitrogen or air.
• The first phase and the second phase may occur concurrently. In another embodiment, the first phase and the second phase do not occur concurrently, but are offset in time.
• In one embodiment, a heat relocation media is used to store and utilize the thermal energy being transferred in this method. In one embodiment,cold stream107 and/orhot stream111 consists of aheat relocation media113. Theheat relocation media113 may comprise a solid heat transfer media. The solid heat transfer media may be metal particles, carbon particles, pebbles, sand, shot, or ceramic particles. The solid heat transfer media may comprise solid or hollow spheres. The solid spheres may be made of ceramic, glass, or quartz. The hollow spheres may be comprised ceramic, glass, or quartz. The solid heat transfer media may comprise solid metal spheres. The metal may be steel, bronze, brass, iron, or copper.FIG. 3 illustrates an example of one possible embodiment, wherein theheat relocation media113 is gravity fed.FIG. 4 illustrates an example of one possible embodiment, wherein theheat relocation media113 is transported by means of an auger.
• Referring toFIG. 5, during the first phase,cold stream107 may consist of aheat relocation media113. In this non-limiting example, theheat relocation media113 is depicted as balls (either hollow or solid), but as discussed above, other alternatives are possible. Theheat relocation media113 may be moved along by means of gravity (as illustrated), an auger, or any other means known in the art. In this embodiment, higher temperature stream105 (which may be a gas) enters into the top ofsecond heat exchanger104, wherein it passes through a firstperforated region114 which allows thehigh temperature stream105 to pass through, but does not allow passage of theheat relocation media113.Higher temperature stream105 comes into direct contact with theheat relocation media113. Coldheat relocation media107 are heated up to formwarmer stream108, and thehigher temperature stream105 is cooled, and may be at least partially condensed, to formcooler stream106.Cooler stream106 then passes through a secondperforated region115 which allows the warmheat relocation media108 to continue, but allows thecooler stream106 to be separated. At this time, warmheat relocation media108 are transported tohigher temperature reservoir102, which serves as a heat sink and stores the captured heat for later usage.
• Referring toFIG. 6, lower temperature stream109 (which may be a liquid) enters into the bottom offirst heat exchanger103.Lower temperature stream109 comes into direct contact with theheat relocation media113.Lower temperature stream109 then passes through a thirdperforated region116 which allows thelower temperature stream109 to pass through, but does not allow passage of theheat relocation media113.Hot stream111 are cooled down to formcolder stream112, and thelower temperature stream109 is heated, and may be at least partially vaporized, to formwarmer stream110.Warmer stream110 the passes through aperforated region117 which allows thewarmer stream110 to pass through, but does not allow passage of theheat relocation media113. At this time, coldheat relocation media112 are transported tolower temperature reservoir101, which serves as a cold sink and stores the captured cold for later usage. This allows the vaporizing and liquefying stages to be decoupled, thereby allowing more flexibility in the system to accommodated varying demands.

Claims (20)

1. A method to store and utilize thermal energy, comprising:

providing a higher temperature stream, and a lower temperature stream,

providing a higher temperature reservoir,

during a first phase,

transferring heat from said higher temperature stream to said high temperature reservoir, thereby at least partially liquefying said higher temperature stream; and

during a second phase,

transferring heat to said lower temperature stream from said higher temperature reservoir, thereby at least partially vaporizing said lower temperature stream

2. The method ofclaim 1, wherein said lower temperature stream is selected from the group consisting of essentially pure oxygen, essentially pure nitrogen, air.

3. The method ofclaim 1, wherein said higher temperature stream is selected from the group consisting of essentially pure oxygen, essentially pure nitrogen, air.

4. The method ofclaim 1, wherein said first phase and said second phase do not occur concurrently.

5. The method ofclaim 1, wherein said first phase and said second phase occur concurrently.

6. A method to store and utilize thermal energy, comprising:

providing a heat relocation media,

providing a higher temperature stream, and a lower temperature stream,

providing a heat transfer means between said higher temperature stream and said heat relocation media,

providing a heat transfer means between said lower temperature stream and said heat relocation media,

providing a higher temperature reservoir and a lower temperature reservoir,

providing a heat transfer means between said heat relocation media and said higher temperature reservoir,

providing a heat transfer means between said heat relocation media and said lower temperature reservoir,

during a first phase,

transferring heat from said heat relocation media to said lower temperature reservoir,

transferring heat from said higher temperature stream to said heat relocation media,

transferring heat from said heat relocation media to said high temperature reservoir, thereby at least partially liquefying said higher temperature stream; and

during a second phase,

transferring heat from said higher temperature reserve to said heat relocation media,

transferring heat from said heat relocation media to said lower temperature stream,

transferring heat from said heat relocation media to said lower temperature reservoir, thereby at least partially vaporizing said lower temperature stream.

7. The method ofclaim 6, wherein said heat relocation media comprises a solid heat transfer media.

8. The method ofclaim 7, wherein said solid heat transfer media is selected from the group consisting of metal particles, carbon particles, pebbles, sand, shot, and ceramic particles.

9. The method ofclaim 7, wherein said solid heat transfer media comprise solid spheres.

10. The method ofclaim 7, wherein said solid heat transfer media comprise hollow spheres.

11. The method ofclaim 9, wherein said solid spheres are comprised of a material selected from the group consisting of ceramic, glass, or quartz.

12. The method ofclaim 10, wherein said hollow spheres are comprised of a material selected from the group consisting of ceramic, glass, or quartz.

13. The method ofclaim 9, wherein said solid heat transfer media comprises solid metal spheres.

14. The method ofclaim 9, wherein said metal is selected from the group consisting of steel, bronze, brass, iron, and copper.

15. The method ofclaim 6, wherein said lower temperature stream is selected from the group consisting of essentially pure oxygen, essentially pure nitrogen, air.

16. The method ofclaim 6, wherein said higher temperature stream is selected from the group consisting of essentially pure oxygen, essentially pure nitrogen, air.

17. The method ofclaim 6, wherein said first phase and said second phase do not occur concurrently.

18. The method ofclaim 6, wherein said first phase and said second phase occur concurrently.

19. The method ofclaim 6, wherein the amount of heat transferred from said higher temperature stream to said heat relocation media is greater than the amount of heat transferred from said heat relocation media to said lower temperature stream.

20. The method ofclaim 6, wherein the amount of heat transferred from said higher temperature stream to said heat relocation media is less than the amount of heat transferred from said heat relocation media to said lower temperature stream.

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