Heat exchanger for concentrating solar collectors and method for making the heat exchanger

• US 4,397,303 A
• Filed: 02/09/1981
• Issued: 08/09/1983
• Est. Priority Date: 02/09/1981
• Status: Expired due to Fees

• Current Assignee: Contech Construction Products Incorporated (THE QUIKRETE Cos. LLC)
• Original Assignee: Armco Inc. (Cleveland-Cliffs Steel Holding Corp.)
• Inventors: Stultz, Richard A.
• Primary Examiner(s): Jones, Larry
• Application Number:
  US06/232,573
• Time in Patent Office: 911 Days
• Field of Search: 126/444, 126/445, 126/438, 126/439, 126/417, 126/432, 126/440, 126/442, 165/164, 165/165, 165/166, 165/76, 165/78, 138/37, 138/38, 29/157.3 R, 29/428, 136/244, 136/246
• US Class Current: 126/651
• CPC Class Codes: F24S 10/502 having conduits formed by paired plates and internal partition means
• 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 23/30 with lenses
• CPC Class Codes: H01L 31/0521 using a gaseous or a liquid coolant, e.g. air flow ventilation, water circulation
• CPC Class Codes: H01L 31/0547 comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
• CPC Class Codes: H02S 40/44 Means to utilise heat energy, e.g. hybrid systems producing warm water and electricity at the same time directly associated with the PV cell or integrated with the PV cell H01L31/0525
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02E 10/44 Heat exchange systems
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• CPC Class Codes: Y02E 10/60 Thermal-PV hybrids
• CPC Class Codes: Y10S 126/907 Absorber coating
• CPC Class Codes: Y10T 29/49355 Solar energy device making
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A heat exchanger assembly for use with concentrating solar collectors of the type employing an elongated conduit for transporting a heat exchange fluid, the heat exchanger being positioned within an opening in the upper surface of the conduit and operating to transfer heat to the heat exchange fluid. The heat exchanger includes a plurality of stacked heat conducting heat exchanger plates having grooves oriented to form flow passage extending in the direction of fluid flow. The heat exchanger includes an alignment feature to insure proper alignment of the flow passages with the direction of heat exchange fluid flow. The grooved heat exchange plates may be fabricated by stamping from a sheet of heat conducting material to facilitate manufacturing of the heat exchanger. In another embodiment, the plates are positioned normal to the fluid flow direction with openings in the plates serving to form flow channels. The heat exchanger is usuable with collectors employing either photovoltaic cells or a solar radiation absorbing flat plate collector.

Claims

1. An assembly for collecting solar energy comprising:

conduit means for transporting a heat exchange fluid, said conduit means including an opening in the upper surface thereof;

heat exchanger means positioned within said opening and extending into said conduit means comprising a plurality of stacked heat conducting heat exchanger plates having means oriented to form flow passages extending in the direction of fluid flow, said orienting means including means for aligning said plates with each other to assure that said flow passages extend in the direction of fluid flow; and

means for converting solar radiation to heat energy positioned on said heat exchanger means, said heat exchanger means operating to transfer heat from said converting means to the heat exchange fluid.

2. The solar energy collecting assembly according to claim 1 wherein said flow passage forming means comprises a plurality of spaced grooves formed in the surface of said plates.

3. The solar energy collecting assembly according to claim 2 including a pair of upwardly and outwardly sloping side walls forming a trough-like concentrating collector housing overlying and extending parallel to said conduit means, said converting means being positioned between said walls.

4. The solar energy collecting assembly according to claim 3 including means for pivoting said assembly for tracking the sun to optimize the amount of solar radiation impinging on said converting means.

5. The solar energy collecting assembly according to claim 2 wherein each of said heat exchanger plates includes a plurality of spaced parallel grooves on one surface only.

6. The solar energy collecting assembly according to claim 5 wherein said plates are stacked such that said grooves of adjacent plates are non-adjacent.

7. The solar energy collecting assembly according to claim 2 wherein said plates are positioned longitudinally in stacked overlying relationship within said conduit.

8. The solar energy collecting assembly according to claim 7 wherein said flow passage forming means comprises a plurality of spaced grooves formed on the surface of said plates.

9. The solar energy collecting assembly according to claim 8 wherein said converting means comprises photovoltaic cell means for converting solar radiation to electrical energy.

10. The solar energy collecting assembly according to claim 8 wherein said converting means comprises a heat conducting plate-like member positioned in heat transfer relationship with said stacked plates, the upper surface of said member including a solar radiation absorbing coating.

11. The solar energy collecting assembly according to claim 1 including a plurality of said heat exchanger means and converting means mounted in separate ones of said openings spaced along said conduit means.

12. The solar energy collecting assembly according to claim 1 including means within said conduit means for forcing substantially all of the heat exchange fluid to pass through said flow passages.

13. The solar energy collecting assembly according to claim 1 wherein said alignment means comprises means for aligning said heat exchanger means within said conduit means.

14. The solar energy collecting assembly according to claim 1 wherein said converting means comprises photovoltaic cell means for converting solar radiation to electrical energy.

15. The solar energy collecting assembly according to claim 1 wherein said converting means comprises a heat conducting plate-like member positioned in heat transfer relationship with said stacked plates, the upper surface of said member including a solar radiation absorbing coating.

16. The solar energy collecting assembly according to claim 2 wherein said heat exchanger means comprises:

a heat conducting plate-like upper segment having an upper surface forming said converting means and wherein said orienting means includes keying means associated with the lower surface of said upper segment and means associated with said heat exchanger plates for mating with said keying means to prevent relative rotation between said plates and said upper segment and to orient said grooves to extend in the direction of fluid flow;

and

a lower segment having an upper surface configured to support the lowermost one of said heat exchanger plates, means for preventing relative rotation between said upper segment and said lower segment, and means for aligning said lower segment within said conduit.

17. The solar energy collecting assembly according to claim 16 wherein said keying means comprises a shaped rod-like member depending from said upper segment, and said mating means comprises an aperture in said heat exchanger plate of a shape configured to cooperate with said rod-like member.

18. The solar energy collecting assembly according to claim 17 wherein said means for preventing relative rotation between said upper and lower segments comprises a bore in the upper surface of said lower segment of a shape configured to cooperate with said rod-like member.

19. The solar energy collecting assembly according to claim 18 wherein said means for aligning said lower segment within said conduit comprises a pair of tab members extending inwardly from the side walls of said conduit means and grooves in the outer edges of said lower segment configured to mate with said tab members.

20. The solar energy collecting assembly according to claim 19 wherein said tab members and said lower segment are configured to block fluid flow through the lower portion of said conduit means for forcing substantially all of the heat exchange fluid to pass through said flow passages.

21. The solar energy collecting assembly according to claim 16 wherein said converting means comprises photovoltaic cell means for converting solar radiation to electrical energy.

22. The solar energy collecting assembly according to claim 16 wherein the upper surface of said upper segment is provided with a solar radiation absorbing coating.

23. The solar energy collecting assembly according to claim 16 wherein said plates are of circular shape.

24. The solar radiation collecting assembly according to claim 14 wherein said plates are of square shape.

25. The solar energy collecting assembly according to claim 1 wherein said plates are positioned substantially normal to the direction of fluid flow.

26. The solar energy collecting assembly according to claim 25 wherein said flow passage forming means comprises a plurality of spaced openings extending through said plates.

27. The solar energy collecting assembly according to claim 26 including means associated with the inner surfaces of said conduit for maintaining said plates in spaced relationship.

28. The solar energy collecting assembly according to claim 27 wherein said converting means comprises photovoltaic cell means for converting solar radiation to electrical energy.

29. The solar energy collecting assembly according to claim 27 wherein said converting means comprises a heat conducting plate-like member positioned in heat transfer relationship with said stacked plates, the upper surface of said member including a solar radiation absorbing coating.

30. The solar energy collecting assembly acording to claim 1 including a liquid heat exchange fluid within said conduit means.

31. In an assembly for collecting solar energy having conduit means containing an opening in the upper surface for transporting a heat exchange fluid, heat exchanger means positioned within said opening and extending into said conduit means, and means for converting solar radiation to heat energy positioned on the heat exchanger means, the heat exchanger means operating to transfer heat from the converting means to the heat exchange fluid, a method for making the heat exchanger comprising:

providing a plurality of heat conducting plates having means for forming a plurality of flow passages;

stacking said plates in adjacent relationship and orienting said plates with respect to each other and said conduit such that said flow passage forming means form flow passageways extending generally in the direction of fluid flow within the conduit to permit flow of the heat exchange fluid therethrough when said stacked plates are mounted within the conduit means opening; and

providing means for mounting said heat exchanger within said opening.

32. The method according to claim 31 wherein said plates are formed by stamping from a sheet of heat conducting material.

33. The method according to claim 31 including providing said plates with said flow passage forming means comprising a plurality of spaced grooves.

34. The method according to claim 33 wherein said grooves are formed by stamping.

35. The method according to claim 33 wherein said grooves are formed in spaced parallel relationship on one surface only of said plates.

36. The method according to claim 33 including the step of orienting said plates such that said grooves of adjacent plates are non-adjacent.

37. The method according to claim 33 including the step of arranging said plates such that they extend longitudinally within said conduit.

38. The method according to claim 33 including the step of providing a plurality of spaced openings and mounting means, and positioning stacked plates within each of said openings.

39. The method according to claim 31 including providing said plates with said flow passage means comprising a plurality of spaced apertures.

40. The method according to claim 39 wherein said plates are stacked in non-contiguous relationship.