WO2009074602A2 - Led lighting system cooled with aqueous liquid, in particular for greenhouses - Google Patents
Led lighting system cooled with aqueous liquid, in particular for greenhouses Download PDFInfo
- Publication number
- WO2009074602A2 WO2009074602A2 PCT/EP2008/067201 EP2008067201W WO2009074602A2 WO 2009074602 A2 WO2009074602 A2 WO 2009074602A2 EP 2008067201 W EP2008067201 W EP 2008067201W WO 2009074602 A2 WO2009074602 A2 WO 2009074602A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- lighting system
- cooling liquid
- led light
- aqueous cooling
- light sources
- Prior art date
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
- F21V29/50—Cooling arrangements
- F21V29/56—Cooling arrangements using liquid coolants
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G9/00—Cultivation in receptacles, forcing-frames or greenhouses; Edging for beds, lawn or the like
- A01G9/24—Devices or systems for heating, ventilating, regulating temperature, illuminating, or watering, in greenhouses, forcing-frames, or the like
- A01G9/249—Lighting means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
- F21Y2115/00—Light-generating elements of semiconductor light sources
- F21Y2115/10—Light-emitting diodes [LED]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S362/00—Illumination
- Y10S362/80—Light emitting diode
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Environmental Sciences (AREA)
- Arrangement Of Elements, Cooling, Sealing, Or The Like Of Lighting Devices (AREA)
- Greenhouses (AREA)
Abstract
A lighting system is provided comprising a plurality of LED light sources in heat conductive contact with an aqueous cooling liquid. The lighting system comprises a means for inhibiting algae growth in the aqueous cooling liquid. The lighting system is particularly suitable for lighting a greenhouse. The cooling liquid keeps the surface temperature of the LED light sources low enough to allow them to be positioned close to the plants being grown in the greenhouse, thus providing considerable space savings.
Description
LED LIGHTING SYSTEM COOLED WITH AQUEOUS LIQUID
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The invention relates generally to a lighting system comprising a plurality of LED light sources cooled by an aqueous liquid, and more particularly to such a system comprising a means for inhibiting algae growth in the aqueous cooling liquid.
2. Description of the Related Art
[0002] Conventional light sources, such as incandescent bulbs and gas discharge tubes, require an elevated operation temperature for the emission of light. By contrast, light emitting diodes ("LEDs") do not require an elevated temperature for light emission. In fact, the light yield of LEDs is greater if the temperature at the p-n junction is kept as low as possible.
[0003] WO2007/093607 discloses a LED-based lighting system whereby individual LED light sources are taken up in a transparent tube through which a cooling fluid is circulated. The focus is on cooling temperatures well below 0 0C, which requires the use of cooling fluids having a low freezing point. Such cooling fluid are expensive, and may be corrosive or toxic.
[0004] Thus, there is a particular need for LED-based lighting systems cooled with an aqueous cooling fluid. There is a further need for such a system comprising means for preventing algae growth in the cooling liquid.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention addresses these problems by providing a lighting system comprising a plurality of LED light sources in heat conductive contact with an aqueous cooling liquid, said lighting system further comprising means for inhibiting algae growth in said aqueous cooling liquid.
[0006] The means for inhibiting algae growth may be an algaecide that is dissolved in the aqueous cooling liquid.
[0007] In another embodiment an algaecide is immobilized on a support and present in a fixed bed through which the cooling fluid is circulated.
[0008] In yet another embodiment the means for inhibiting algae growth comprises a closed, substantially light-tight circuit for circulating the aqueous cooling liquid.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0009] The following is a description of certain embodiments of the invention, given by way of example only.
[0010] The present invention is based on the discovery that aqueous cooling liquids may be used for the cooling of LED-based light sources. Although aqueous cooling liquids do not permit cooling temperatures much below 0 0C, it has been found that such cooling nevertheless provides significant gains in the light output of the LEDs. This gain far outweighs the investment cost of the cooling system and the cost of operating the cooling system. In any event, heat removed from the lighting system may be recovered and used for heating, for providing hot water, and other useful purposes.
[0011] The use of an aqueous liquid for cooling has many advantages. Water is plentiful, and its cost as compared to other cooling fluids is low. Water is also non-toxic, and by itself non-corrosive if care is taken to remove excess oxygen from the aqueous liquid.
[0012] It has been discovered, however, that aqueous cooling liquids rapidly become contaminated with algae. Another aspect of the present invention therefore is a means for inhibiting algae growth in the aqueous liquid.
[0013] Thus, the present invention provides :
A lighting system comprising a plurality of LED light sources in heat conductive contact with an aqueous cooling liquid, said lighting system further comprising means for inhibiting algae growth in said aqueous cooling liquid.
[0014] The invention encompasses three different embodiments for the means for inhibiting algae growth.
[0015] The first embodiment comprises an algaecide mixed with the aqueous cooling liquid. Suitable algaecides include those that are used in swimming pools, such as chlorine and ozone. It has been found that glycol compounds, such as ethylene glycol, are suitable algaecides. Glycol compounds have the additional advantage of lowering the freezing point of aqueous
liquids, thereby permitting operation of the cooling system at lower temperatures and protecting the cooling system against accidental freezing.
[0016] In a second embodiment the algaecide is immobilized on a support, and the cooling liquid is circulated through a fixed bed of the immobilized algaecide. For example, silver or copper ions are effective algaecides. Silver and copper ions may be immobilized on zeolite particles by ion exchange. A fixed bed of zeolites particles may have the form of a filter cartridge filled with the zeolites particles. During operation of the cooling system the cooling liquid is circulated through the zeolite-charged cartridge. Small amounts of silver and/or copper ions are released from the zeolite when cooling liquid is circulated through the fixed zeolite bed. In addition, mobile algae fibers come into contact with the immobilized silver ions, and become killed. Dead algae debris may be removed from the cooling circuit using suitable filters.
[0017]
In the alternative a so-called Algae Bar ™ may be placed in the circulation circuit for the cooling liquid. The Algae bar™, available from Simple Mfg.,
P.O Box 8447
Moreno Valley, CA
92552-8447 comprises a rod of copper coated with silver. In contact with water it slowly releases copper and silver ions. The rate of release may be adjusted by controlling the pH of the aqueous cooling liquid.
[0018] In a third embodiment the means for inhibiting algae growth comprises a closed, substantially light-tight circuit for circulating the aqueous cooling liquid. It has been found that algae growth is effectively inhibited if light is not allowed to enter the cooling circuit. It will be understood that aspects of these three embodiments may be combined. For example, a substantially light-tight circuit may be filled with an aqueous cooling liquid comprising low concentrations of an algaecide, or a fixed bed of immobilized algaecide.
[0019] Accordingly, in this embodiment the light-tight circuit for circulating the aqueous cooling liquid may comprise tubes of an opaque material. The tube material may be rigid or flexible. Examples of rigid material include copper and aluminum tubing, and hard polyvinylchloride (PVC) tubing. Copper has the advantage that copper ions act as algaecides. Examples of flexible tubing include flexible water pipes as are used in home and building construction.
[0020] Desirably the LED light sources are provided with a substantially light-tight flow chamber. This may be accomplished by constructing the flow chamber of an opaque material, such as aluminum.
[0021] The lighting system is preferably designed for quick installation. In a preferred embodiment the present invention provides a lighting system comprising: a) a plurality of LED light sources, each provided with a flow chamber for aqueous cooling liquid, said flow chambers being provided with flanges for connecting tubing; b) a plurality of tube lengths; c) clip joints for connecting the tube lengths to flanges of the flow chambers.
[0022] The system may further comprise power lines for providing electric power to the plurality of LEDs, a pump for circulating the cooling liquid, a heat exchanger for extracting heat from the cooling liquid, a cooling unit, and the like.
[0023] Desirably, the cooling capacity of the system is designed such that the LED light sources, when in use, have a surface temperature below 50 0C, preferably below 45 0C. The amount of heat generated by a LED light source at its target operating temperature can be easily measured, or calculated from the amount of electric energy supplied and the amount of light being generated, the balance being generated heat. This straightforward calculation provides the basis for designing the cooling capacity of the system, using standard HVAC methods.
[0024] The lighting system of the present invention may be used in any environment where LED lighting is used. The system is particularly suitable for larger projects, such as office buildings, supermarkets, warehouses, greenhouses, and the like.
[0025] For applications such as greenhouses it is important to use algaecides of low human toxicity, so that the minimum inhibitory concentration is lower than toxicity limits for contact with food crops. This is to ensure that any unforeseen leakage of the cooling circuit does not render food crops as may be present in the greenhouse unsuitable for consumption.
[0026] When used in a greenhouse, the lighting system may be mounted near the ceiling of the greenhouse, which is the customary location for conventional greenhouse lighting. However, the low surface temperature of the LED light sources makes it possible to position the light sources much closer to the plants than was heretofore possible. For example, the lighting system may be provided at least in part below the canopy of the plants being grown in the greenhouse. It is also possible to place the lighting system closely above the plants.
[0027] The possibility of placing the light sources in close proximity to the plants makes it possible to improve the use of space in a greenhouse. It will be appreciated that greenhouse space is at a premium, and any improvement in space utilization provides significant cost savings. The lighting system of the present invention makes it possible to stack layers of plant growing surfaces within a greenhouse, thereby doubling, tripling or even quadrupling the available growing surface.
[0028] Accordingly, another aspect of the present invention is a greenhouse comprising at least two growing levels, each growing level comprising: a) a lighting system comprising liquid-cooled LED light sources whereby, when in use, the LED light sources have a surface temperature of below 50 0C, preferably below 45 0C; b) a growth medium positioned at a level below said lighting system.
Claims
1. A lighting system comprising a plurality of LED light sources in heat conductive contact with an aqueous cooling liquid, said lighting system further comprising means for inhibiting algae growth in said aqueous cooling liquid.
2. The lighting system of claim 1 wherein the means for inhibiting algae growth comprises an algaecide dispersed or dissolved in the aqueous cooling liquid.
3. The lighting system of claim 1 or 2 wherein the means for inhibiting algae growth comprises an immobilized bed comprising an algaecide, whereby the aqueous cooling liquid is circulated through the immobilized bed.
4. The lighting system of claim 2 or 3 wherein the algaecide comprises silver ions.
5. The lighting system of any one of claims 1 - 4 wherein the means for inhibiting algae growth comprises a closed, substantially light-tight circuit for circulating the aqueous cooling liquid.
6. The lighting system of claim 5 wherein the light-tight circuit for circulating the aqueous cooling liquid comprises tubes of an opaque material.
7. The lighting system of claim 6 wherein the tubes are flexible.
8. The lighting system of claim 6 wherein the tubes are rigid.
9. The lighting system of any one of the preceding claims wherein the LED light source comprises a flow chamber for the aqueous cooling liquid, said flow chamber being constructed in an opaque material.
10. The lighting system of claim 9 wherein the opaque material is aluminum.
11. The lighting system of any one of the preceding claims comprising a) a plurality of LED light sources, each provided with a flow chamber for aqueous cooling liquid, said flow chambers being provided with flanges for connecting tubing; b) a plurality of tube lengths; c) clip joints for connecting the tube lengths to flanges of the flow chambers.
12. The lighting system of any one of the preceding claims whereby, when in use, the LED light sources have a surface temperature below 50 0C, preferably below 45 0C.
13. The lighting system of any one of the preceding claims when used in a greenhouse.
14. The lighting system of claim 13 which is provided near the ceiling of the greenhouse.
15. The lighting system of claim 13 which is provided at least in part below the canopy of plants being grown in the greenhouse.
16. A greenhouse comprising at least two growing levels, each growing level comprising: a) a lighting system comprising liquid-cooled LED light sources whereby, when in use, the LED light sources have a surface temperature of below 50 0C, preferably below 45 0C; b) a growth medium positioned at a level below said lighting system.
17. The greenhouse of claim 16 wherein the lighting system is a lighting system according to any one of claims 1 - 15.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US99687607P | 2007-12-10 | 2007-12-10 | |
US60/996,876 | 2007-12-10 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2009074602A2 true WO2009074602A2 (en) | 2009-06-18 |
WO2009074602A3 WO2009074602A3 (en) | 2009-07-30 |
Family
ID=40386237
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2008/067201 WO2009074602A2 (en) | 2007-12-10 | 2008-12-10 | Led lighting system cooled with aqueous liquid, in particular for greenhouses |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2009074602A2 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10856470B2 (en) | 2017-09-19 | 2020-12-08 | Agnetix, Inc. | Fluid-cooled LED-based lighting methods and apparatus for controlled environment agriculture |
US10959383B2 (en) | 2018-05-04 | 2021-03-30 | Agnetix, Inc. | Methods, apparatus, and systems for lighting and distributed sensing in controlled agricultural environments |
US10999976B2 (en) | 2017-09-19 | 2021-05-11 | Agnetix, Inc. | Fluid-cooled lighting systems and kits for controlled agricultural environments, and methods for installing same |
US11013078B2 (en) | 2017-09-19 | 2021-05-18 | Agnetix, Inc. | Integrated sensor assembly for LED-based controlled environment agriculture (CEA) lighting, and methods and apparatus employing same |
US11076536B2 (en) | 2018-11-13 | 2021-08-03 | Agnetix, Inc. | Fluid-cooled LED-based lighting methods and apparatus for controlled environment agriculture with integrated cameras and/or sensors and wireless communications |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3339066A (en) * | 1965-10-22 | 1967-08-29 | Mark B Hart | Underwater light for swimming pool |
DE4033958A1 (en) * | 1990-10-25 | 1992-04-30 | Ardenne Forschungsinst | Liq. cooling and filter medium for IR high power radiator - is soln. of pigment with absorption edge of 700 nm and antibacterial substance of high optical transparency |
JPH07303809A (en) * | 1994-05-12 | 1995-11-21 | Kenji Nakamura | Water purification filter for water tank |
JPH104852A (en) * | 1996-06-18 | 1998-01-13 | Sliontec:Kk | Sheet for preventing generation of algae and prevention of generation of algae with the same |
EP1300066A1 (en) * | 2000-07-07 | 2003-04-09 | Cosmo Plant Co. Ltd. | Method of producing plants, plant cultivating device, and light-emitting panel |
US20030090893A1 (en) * | 2001-11-12 | 2003-05-15 | James Nepil | Lighting system and device |
JP2003169566A (en) * | 2001-12-07 | 2003-06-17 | San Power Kk | Lighting apparatus for aquarium and aquarium furnished with lighting apparatus |
WO2006069554A1 (en) * | 2004-12-30 | 2006-07-06 | Osram Opto Semiconductors Gmbh | Cooling device for cooling a semiconductor component, in particular, an optoelectronic semiconductor component |
WO2007093607A1 (en) * | 2006-02-17 | 2007-08-23 | Lemnis Lighting Ip Gmbh | Lighting device and lighting system for stimulating plant growth |
WO2008010121A2 (en) * | 2006-07-04 | 2008-01-24 | Koninklijke Philips Electronics N.V. | Cooling semiconductor-based devices arranged in a greenhouse |
EP1933602A1 (en) * | 2006-12-13 | 2008-06-18 | Kooymans Beheer B.V. | Illumination system for growing plants |
-
2008
- 2008-12-10 WO PCT/EP2008/067201 patent/WO2009074602A2/en active Application Filing
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3339066A (en) * | 1965-10-22 | 1967-08-29 | Mark B Hart | Underwater light for swimming pool |
DE4033958A1 (en) * | 1990-10-25 | 1992-04-30 | Ardenne Forschungsinst | Liq. cooling and filter medium for IR high power radiator - is soln. of pigment with absorption edge of 700 nm and antibacterial substance of high optical transparency |
JPH07303809A (en) * | 1994-05-12 | 1995-11-21 | Kenji Nakamura | Water purification filter for water tank |
JPH104852A (en) * | 1996-06-18 | 1998-01-13 | Sliontec:Kk | Sheet for preventing generation of algae and prevention of generation of algae with the same |
EP1300066A1 (en) * | 2000-07-07 | 2003-04-09 | Cosmo Plant Co. Ltd. | Method of producing plants, plant cultivating device, and light-emitting panel |
US20030090893A1 (en) * | 2001-11-12 | 2003-05-15 | James Nepil | Lighting system and device |
JP2003169566A (en) * | 2001-12-07 | 2003-06-17 | San Power Kk | Lighting apparatus for aquarium and aquarium furnished with lighting apparatus |
WO2006069554A1 (en) * | 2004-12-30 | 2006-07-06 | Osram Opto Semiconductors Gmbh | Cooling device for cooling a semiconductor component, in particular, an optoelectronic semiconductor component |
WO2007093607A1 (en) * | 2006-02-17 | 2007-08-23 | Lemnis Lighting Ip Gmbh | Lighting device and lighting system for stimulating plant growth |
WO2008010121A2 (en) * | 2006-07-04 | 2008-01-24 | Koninklijke Philips Electronics N.V. | Cooling semiconductor-based devices arranged in a greenhouse |
EP1933602A1 (en) * | 2006-12-13 | 2008-06-18 | Kooymans Beheer B.V. | Illumination system for growing plants |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10856470B2 (en) | 2017-09-19 | 2020-12-08 | Agnetix, Inc. | Fluid-cooled LED-based lighting methods and apparatus for controlled environment agriculture |
US10999976B2 (en) | 2017-09-19 | 2021-05-11 | Agnetix, Inc. | Fluid-cooled lighting systems and kits for controlled agricultural environments, and methods for installing same |
US11013078B2 (en) | 2017-09-19 | 2021-05-18 | Agnetix, Inc. | Integrated sensor assembly for LED-based controlled environment agriculture (CEA) lighting, and methods and apparatus employing same |
US11044854B2 (en) | 2017-09-19 | 2021-06-29 | Agnetix, Inc. | Fluid-cooled LED-based lighting methods and apparatus for controlled agricultural environments having a vertically-stacked multiple-level growing area |
US11272589B2 (en) | 2017-09-19 | 2022-03-08 | Agnetix, Inc. | Integrated sensor assembly for LED-based controlled environment agriculture (CEA) lighting, and methods and apparatus employing same |
US11310885B2 (en) | 2017-09-19 | 2022-04-19 | Agnetix, Inc. | Lighting system and sensor platform for controlled agricultural environments |
US11678422B2 (en) | 2017-09-19 | 2023-06-13 | Agnetix, Inc. | Lighting system and sensor platform for controlled agricultural environments |
US11889799B2 (en) | 2017-09-19 | 2024-02-06 | Agnetix, Inc. | Fluid-cooled LED-based lighting methods and apparatus for controlled agricultural environments |
US10959383B2 (en) | 2018-05-04 | 2021-03-30 | Agnetix, Inc. | Methods, apparatus, and systems for lighting and distributed sensing in controlled agricultural environments |
US11076536B2 (en) | 2018-11-13 | 2021-08-03 | Agnetix, Inc. | Fluid-cooled LED-based lighting methods and apparatus for controlled environment agriculture with integrated cameras and/or sensors and wireless communications |
US11627704B2 (en) | 2018-11-13 | 2023-04-18 | Agnetix, Inc. | Lighting, sensing and imaging methods and apparatus for controlled environment agriculture |
Also Published As
Publication number | Publication date |
---|---|
WO2009074602A3 (en) | 2009-07-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
ES2821403T3 (en) | Aquaponic Unit | |
WO2009074602A2 (en) | Led lighting system cooled with aqueous liquid, in particular for greenhouses | |
JP7232047B2 (en) | ANTI-FOULING SYSTEM AND CONTROLLER AND METHOD FOR CONTROLLING ANTI-FOULING SYSTEM | |
JP5193235B2 (en) | Fully controlled plant factory system | |
US20190277568A1 (en) | Cooling apparatus for cooling a fluid by means of surface water | |
CN113203241B (en) | Cooling device for cooling a fluid by means of surface water | |
US20220162092A1 (en) | Refrigeration Facility Cooling and Water Desalination | |
JP2018023336A (en) | Plant cultivation apparatus | |
CN1286744C (en) | Method for controlling legionella in cooling towers | |
JP4084352B2 (en) | Multi-stage utilization system for deep ocean water | |
KR20110087124A (en) | Heat pump system of exclusive sea water farming cages | |
TW201708044A (en) | Assembly comprising a wet compartment and at least one anti-fouling energy source | |
BR102014031422A2 (en) | automated and self-sustainable system and method for the production of aquaculture derivatives | |
RU2580583C1 (en) | Agro-biocomplex | |
JP2004060970A (en) | Piping structure of heating system | |
US20230147184A1 (en) | Air transport unit | |
JP6259387B2 (en) | Air conditioning equipment for house for plant cultivation | |
KR101551650B1 (en) | The system of simultaneously employing cooling device and heat pumping device using the heat of storage water | |
JP2017023022A (en) | Rice-growing plant adaptable to extreme area | |
CN213687086U (en) | Wet curtain sterilizer | |
JP2004183967A (en) | Multi-stage type utilization system for heat sink | |
KR20030028790A (en) | Heat pump device for sea water | |
KR20150113256A (en) | Plant Cultivation Apparatus for Plant Factory with Lamp Cooling System | |
KR20210040100A (en) | Liquid desiccant based moisture pumps, evaporative coolers and air purification systems | |
JPH08136014A (en) | Multipurpose artificial watercourses |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 08860356 Country of ref document: EP Kind code of ref document: A2 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 08860356 Country of ref document: EP Kind code of ref document: A2 |