NL2016151B1

NL2016151B1 - Modular greenhouse lighting system.

Info

Publication number: NL2016151B1
Application number: NL2016151A
Authority: NL
Inventors: Johannus Petrus Brok Matheus
Original assignee: Hortilux Schréder B V
Priority date: 2016-01-25
Filing date: 2016-01-25
Publication date: 2017-07-31

Abstract

A modular greenhouse lighting system comprises a driver unit and two or more armatures, wherein each of the armatures comprises a light emitting device and at least one optical element. The armatures are suspended from greenhouse ceilings such that they are arranged in between rows of plants. The armatures are configured to spread the emitted light in substantially sideways direction in order to allow for optimal adsorption of the light by the plants. A single driver unit is configured to apply the voltage to the two or more armatures, wherein the armatures can be interconnected to form an array, wherein the driver unit is configured to supply the voltage to one or more arrays.

Description

Title: Modular greenhouse lighting system

The present invention relates to a modular greenhouse lighting system.

In order to reduce the costs of the cultivation of crops in greenhouses, growers try to reduce energy consumption in greenhouses, in particular the consumption of electricity. The common lighting systems in greenhouses for example rely on sodium lamps, which are suspended from the ceiling of the greenhouses. Such sodium lamps generate a large amount of light in the desired wavelength spectrum, but also consume a relatively high amount of electricity.

It has been found, as can for example be seen in European Patent Application EP 2 567 610 A2, that LED’s (Light Emitting Diodes) emit high intensity light with a low power consumption. A greenhouse lighting system can therefore be made more energy efficient with the arrangement of LED lighting, in particular when lighting fixtures are equipped with optical elements that spread the emitted light in a more horizontal direction in order to obtain a more even distribution of light. A disadvantage of suspending such LED fixtures from the ceiling is however that a large amount of the emitted light is scattered due to a relatively large distance between the light source and the plants. A portion of the emitted light does therefore not reach the plants, but for example spreads across the glass greenhouse ceiling to the environment, resulting in light pollution. A further manner of increasing the energy efficiency of greenhouse lighting, e.g. the relative amount of light received by plants as compared to the amount of emitted light, is to bring the lamps in proximity of the plants, as is disclosed in United States Patent Application US 3,931,695 A. Thereby, less light is scattered on the way to the plants. A disadvantage of bringing the lamps in proximity with the plants, in particular with the presently-used sodium lamps, is however the risk of burning the plants due to a significant amount of heat that is produced by the lamps.

It is an object of the invention to provide a modular greenhouse lighting system that lacks the above-mentioned drawbacks or at least to provide an alternative.

The present invention provides a modular greenhouse lighting system, as claimed in claim 1. The present invention further provides a method for the installation of a modular greenhouse lighting system, as claimed in claim 17.

The modular greenhouse lighting system comprises a driver unit and an armature, wherein the driver unit is configured to supply a voltage to the armature. The armature comprises a light emitting device and at least one optical element. The light emitting device has multiple LED light sources which are configured to emit light when a voltage is applied. The at least one optical element is configured to reflect at least a portion of the light that is emitted by the light emitting device in a desired direction.

The system is configured to be placed in a greenhouse, wherein the plants are cultivated in a substrate that is suspended above the ground. Such substrates are commonly used, due to the horticultural benefits such as good moisture and nutrient control of the soil.

The system comprises two or more armatures. A single driver unit is electrically connected to the two or more armatures and is configured to apply the voltage to the two or more armatures. This has the advantage that the driver unit, which is a relatively expensive part of the system, is not necessarily built in each armature, as was the case in lighting systems from prior art. Therefore, fewer driver units are needed in a system according to the present invention as compared to systems from prior art.

The LED’s in the light emitting device are furthermore very energy efficient and consume a relatively low amount of electrical energy for the same light flux as compared to, for example, previously-used sodium lamps.

Due to the low energy consumption of the LED’s, many, or at least two or more, armatures may be connected to a single driver unit, since the current that is delivered to the LED’s remains relatively low.

The driver unit in the system is configured to be suspended from the substrate. In an embodiment, the driver unit comprises brackets, which are configured to be mounted to the substrate, such that the driver unit can be suspended form the substrate.

The driver unit is suspended such that it will not be arranged in proximity of the armatures. This placement provides additional benefits over prior art systems. It is, for example, better reachable for a technician in case maintenance is required.

The system has a further advantage that it is a flexible system, wherein the amount of armatures per driver unit and/or the amount of driver units in the greenhouse can be altered easily, upon request of the grower. The accessible placement of the driver unit underneath the substrate further enhances this flexibility.

In an embodiment of the system, the driver unit is configured to receive an AC voltage from a power grid, to transform this AC voltage into a DC voltage and to supply the DC voltage to the two or more armatures. The driver unit therefore comprises electronics with which the applied voltage towards the armatures can be controlled.

In the embodiment, the AC voltage has a potential difference of 230 Volt or 400 Volt, and an alternation frequency of 50 Hertz. The DC voltage may have a 12 Volt potential difference.

In an alternative embodiment, the driver unit receives a DC voltage from the power grid and transforms this DC voltage, in case it does not have the desired potential difference, into another DC voltage with the desired potential difference.

In an embodiment, each of the two or more armatures comprises an armature housing, which is configured to hold at least the light emitting element and the at least optical element such that they can, for example, be suspended from a ceiling.

The armature housing stretches in a longitudinal direction, wherein the housing comprises two end portions on each of the ends of the armature housing.

The armature housing comprises a first coupling element, wherein the first coupling element is configured to be coupled to a second coupling element of another armature. Thereby, a rigid coupling is created between the armatures and a substantially linear armature array of at least two armatures is formed. This provides the advantage that the armatures can have a relatively small length, which is convenient for example during transportation. The array may, however, be as long as a greenhouse aisle.

This coupling further provides the advantage that, in case one of the armatures breaks down, only one armature, rather than a complete array, needs to be replaced or repaired.

The array of armatures comprises, in an embodiment an upper fixation element and a lower fixation element to fixate the coupling between armatures in the array.

In an embodiment, each of the two or more armatures in the armature array comprises a first connector and a second connector. These connectors are electrical connectors, which are configured to transmit an electric current. In the armature of the embodiment, the first connector is electrically connected to the light emitting device and the second connector is electrically connected to the first connector.

The second connector of a first armature can be connected to the first connector of a second armature, such that an electrical connection is established between the armatures in the armature array. To be connected into each other, the first connector is a male connector and the second connected is a corresponding female connector or vice versa.

In an embodiment, the first connector is arranged in the first coupling element and the second connector is arranged in the second coupling element. This provides the advantages that the first connector is connected to the second connector when the first coupling element is coupled to the second coupling element.

In an alternative embodiment, the two electrical connectors are configured to be connected to each other firmly. This provides the advantage that the electrical connectors themselves form the coupling elements since the tight fit and internal friction between the connectors is sufficient to keep the armatures, which comprise the connectors, together.

In an embodiment, the driver unit is configured to apply the voltage to the first connector of the first armature, in particular to the first armature in the array.

In an embodiment of the system is the voltage, that is applied to the first armature, further transmitted to each of the armatures in the armature array through the connected second and first connectors. The voltage is applied by the driver unit to the first connector of the first armature and is from there transmitted to the further armatures.

In an embodiment, the system comprises two or more armature arrays. The two or more armature arrays may thereby suspended from the ceiling. A lower array is arranged below an upper array, such that light emitted by the lower array reaches the plants at a lower height as compared to the light emitted by the upper array.

The armatures, or in particular the arrays of armatures, are configured to be suspended in between rows of plants. Thereby, the light is transmitted to the plants more efficiently and the amount of scattered light, which for example scatters through the greenhouse ceiling, will be reduced, thereby increasing the systems efficiency.

The driver unit is, in an embodiment, configured to apply the voltage to the first connector of the first armature of each of the armature arrays. The driver unit is thereby solely connected to the first connector of the first armature of each of the arrays. This further provides that for multiple arrays, in particular arrays that are arranged above each other, a single driver unit is required.

In an embodiment, the light emitting device is arranged in a top portion of each of the armatures. Such a top portion forms part of the armature housing and stretches in a longitudinal directional between two ends of the armature housing. The light emitting device is thereby configured to emit light in a substantially downwards direction, because the light emitting device is arranged on the underside of the top portion.

The at least one optical element is, in an embodiment, configured to reflect at least a portion of the substantially downwards emitted light and to spread at least a portion of the light in a sideways direction. Thereby, the plants are illuminated from a substantially sideways direction, rather than from above. This provides an advantage in that the amount of light adsorbed by the plants, compared to the amount of emitted light, is higher in a system according to the invention, as compared to that in prior art lighting systems.

Furthermore, a single light emitting element can be arranged in the armature, of which the emitted light is reflected in two substantially sideways directions. However, in alternative embodiments of the armature, the light is reflected by the at least one optical element in one sideways direction, in case the armature is for example arranged adjacent a greenhouse wall.

The reflected light is however not reflected in single directions, but is merely spread across a range of directions, such that the light is evenly reflected towards all of the directions that are within this range.

In an embodiment, the light is spread by the at least one optical element in directions that have an angle between -120° and +120° with respect to the substantially downwards direction, in particular between -105° and +105° with respect to the substantially downwards direction.

In an embodiment of the system, the intensity of the emitted light from the light emitting device can be altered. Therefore, the amount of light that reaches the plants can be altered to ensure optimal conditions and to allow for maximum crop yield.

In an embodiment, the driver unit is adapted to change the intensity of the light emitted by the light emitting device by changing the supplied voltage to the armature. Therefore, the light intensity is controlled from a single unit, rather than separately in each of the armatures.

In an embodiment, the height of the arrays of armatures can be adapted to the height of the plants, grown in the substrates. As the plants grow, the height at which the armature arrays are suspended can be adapted accordingly. Therefore, optimal lighting conditions for the plants can be provided. A further advantage is that the driver unit, which is generally heavy compared to the weight of the arrays, can remain stationary suspended from the substrate and does not need to be moved.

The invention provides a method for the installation of a modular greenhouse lighting system as described above, wherein the method comprises the steps of providing a modular greenhouse lighting system as described above.

The method further comprises the step of suspending the two or more armatures from a ceiling of the greenhouse. The two or more armatures are preferably suspended in between plants, such that the plants receive light, emitted by a light emitting element of the armature, from a sideways direction.

The method comprises the step of suspending the driver unit from the substrate, such that the driver unit is connected to the substrate and is not in contact with a greenhouse floor.

The method further comprises the step of connecting an electric cable to the driver unit and to the two or more armatures. Thereby, the driver unit can apply a voltage to the two or more armatures, such that the light emitting elements in the armatures can emit light.

In an embodiment, the method comprises the step of coupling the two or more armatures in order to form an armature array. Thereby, multiple armatures are couple such that the array extends along the length of a greenhouse aisle. The voltage, applied to the array, is configured to be applied by a single driver unit.

Further characteristics and advantages of the greenhouse lighting system according to the invention will be explained in more detail below with reference to embodiments, which are illustrated in the appended drawings, in which:

Figure 1A schematically depicts an armature;

Figure 1B schematically depicts a driver unit;

Figure 2 schematically depicts an embodiment of a modular greenhouse lighting system;

Figure 3A schematically depicts one end of an armature housing with a first coupling element;

Figure 3B schematically depicts another end of an armature housing with a second coupling element;

Figures 3C schematically depicts a rigid coupling between two armatures;

Figure 4A schematically depicts an armature array;

Figure 4B schematically depicts another embodiment of the modular greenhouse lighting system, comprising two armature arrays with a single driver unit; and

Figure 5 schematically depicts a greenhouse comprising a modular greenhouse lighting system according to the invention.

Throughout the figures, the same reference numbers are used to refer to corresponding components or components which have a corresponding action.

Figure 1A discloses a schematic representation of an armature 10 of the modular greenhouse lighting system 1. The armature 10 comprises an armature housing 11, which is substantially elongated along a longitudinal axis (L). The armature 10 comprises a light emitting device 12, which is arranged on a middle portion of the armature housing 11 and is substantially elongate along the longitudinal axis (L) as well.

The light emitting device 12 comprises multiple LED (Light Emitting Diode) light sources 13 which are configured to emit light when a voltage is applied. The LED light sources 13 are disposed in the light emitting device 12 in a direction parallel to the longitudinal axis (L).

The light emitting device 12 is arranged in a top portion 14 of the armature 10. The top portion 14 forms part of the armature housing 11. The light emitting device 12 is thereby arranged such that the LED light sources 13 face a substantially downwards direction (D) and are configured to emit light in the substantially downwards direction (D).

The armature 10 comprises an optical element 15, which comprises a mirror surface 16 that is configured to reflect light. The optical element 15 is thereby configured to reflect at least a portion of the light that is emitted by the light emitting device 12 in a desired direction. The mirror surface 16 of the optical element 15 faces the light emitting device 12 and is thereby directed in a substantially upwards direction (U).

The mirror surface 16 comprises many facets which are configured to spread the emitted light from the light emitting device 12, rather than to reflect it in a certain specific direction. The optical element 15 is configured to reflect light in all directions having an angle with the substantially downwards direction (D) in between -105°and +105°.

The substantially sideways reflected light, in directions as described above, causes the plants to receive more light as compared to with the prior art lamps, in which the light was emitted substantially downwards.

In figure 1B, a driver unit 20 is schematically represented. The driver unit 20 comprises a body 21, which is configured to provide a protected space for electronic components that are arranged inside the body 21.

The driver unit 20 is configured to apply a voltage to the two or more armatures 10. Thereto, the driver unit 20 comprises two driver unit connectors 22 through which the voltage is applied to the two or more armatures 10.

The driver unit 20 is configured to be suspended from the substrate 4. Thereto, the body 21 comprises two brackets 23, which are mounted on the body 21. Each of the brackets 23 has two hooking elements 24 on opposite sides, with which the brackets 23, and therefore the driver unit 20, can be suspended from the substrate 4.

In figure 2, an embodiment of the modular greenhouse lighting system 1 is schematically represented. The system 1 comprises two armatures 10 and a single driver unit 20. Another embodiment of the system 1 may comprise more armatures 10.

The driver unit 20 is configured to apply a voltage to the two armatures 10, such that the LED light sources 13 in the light emitting elements 12 of each of the armatures 10 can emit light. To supply the voltage to the armatures 10, electric cables 2 extend from the driver unit connectors 22 to the armatures 10.

The driver unit 20 receives an AC voltage from a power grid 3, wherein the AC voltage for example has a potential difference of 230 Volt and a frequency of 50 Hertz. The driver unit 20 is configured to transform the AC voltage in to a DC voltage, which for example has a potential difference of 12 Volt. The DC voltage is then supplied by the driver unit 20, through the electric cable 2, to the armatures 10.

In figure 3A, one end 17 of the armature housing 11 of the armature 10 is schematically displayed. The one end 17 of the armature housing 11 comprises a first coupling element 31. In the first coupling element 31, a first connector is arranged 41. The first coupling element 31 is a female coupling element, which is configured to firmly receive a corresponding male counterpart.

In figure 3B, another end 18 of the armature housing 11 of the armature 10 is schematically displayed. The other end 18 of the armature housing 11 comprises a second coupling element 32. In the second coupling element 32, a second connector is arranged 42. The second coupling element 32 is a male coupling, which is configured to be inserted in the female coupling element.

The first coupling element 31 and the second coupling element 32 of different armatures 10 are configured to be coupled, such that a rigid coupling 33 between the both coupling elements, and therefore between both armatures 10, is created. The first connector 41 and the second connector 42 are arranged respectively in the first coupling element 31 and the second coupling element 32, so a rigid coupling 33 between both coupling elements also provides an electrical connection 43 between both connectors. Thereby, an electrical connection 43 is provided between both armatures 10, such that a voltage applied to a first armature 10 is transmitted to a further armature 10’.

In figure 3C, a first armature 10 and further armature 10’ are displayed having a first armature housing 11 and a further armature housing 11’, wherein the second coupling element 32 of the first armature 10 is coupled to the first coupling element 31 of the further armature 10’. The first connector 41 and second connector 42, arranged in respectively the first coupling element 31 and the second coupling element 32 are thereby connected as well.

The system 1 with coupled armatures comprises an upper fixation element 51 and a lower fixation element 52 between the first armature 10 and the further armature 10’. The upper 51 and lower 52 fixation elements are configured to fixate the coupling 33 between both armatures. Thereby, the coupling 33 cannot be disengaged and the connection 43 between the first connector 31 and the second connector 32 will remain intact, even though a force might be applied such that the coupling elements tend to be pulled apart.

With the coupling of the first armature 10 and the second armature 10’, an armature array 50 is created, wherein the array 50 comprises two armatures 10. In another embodiment, the array 50 comprises more than two armatures 10, as another further armature 10" is connected to the further armature 10’, in a manner just as the first armature 10 is coupled to the further armature 10’.

In figure 4A, an armature array 50 is schematically displayed, wherein the array 50 comprises four armatures (10,10’, 10”, 10’”) and wherein the array 50 stretches in a direction that is parallel to the longitudinal axis (L) of each of the armatures 10.

The array 50 is configured to be suspended from a greenhouse ceiling, such that it is arranged in between the plants, in particular that it is arranged in between rows of plants.

The plants thereby receive the light from the system 1 in a substantially sideways direction, such that the efficiency, e.g. the amount of light adsorbed by the plants with respect to the amount of emitted light, is higher for the system 1 according to the invention rather than for prior art lighting systems.

In figure 4B, another embodiment of a modular greenhouse lighting system 1 is displayed, wherein the system 1 comprises a single driver unit 20 and two arrays 50 of armatures 10, wherein each array 50 comprises four armatures 10.

The driver unit 20 receives an AC voltage from the power grid 3 and is configured to transform the AC voltage into a DC voltage. The driver unit 20 is configured to transmit the DC voltage through the electric cables 2 towards the first armature 10 of each of the arrays 50.

The driver unit 20 is configured to apply the DC voltage to one or more arrays 50. In the embodiment of the system 1, the driver unit 20 applies the voltage to the two arrays 50.

In the embodiment, the arrays 50 are arranged above each other, such that they will emit light to the same adjacent rows of plants. However, the height, at which the light is supplied to the plants, will vary for each of the arrays 50, due to the difference in height.

In figure 5, at least a section of a greenhouse 100 comprising the modular greenhouse lighting system 1 is displayed. In the greenhouse 100, rows of plants 101 are grown in substrates 4, which are suspended from a greenhouse ceiling 102. In between the plants 101, the arrays 50 of armatures 10 are suspended from the ceiling 102. The driver unit 20 is suspended underneath the substrates 4 by means of brackets 23. The driver unit 20 is configured to apply the voltage to the arrays 50 through electric cables 2.

Claims

A modular greenhouse lighting system for illuminating rows of plants, wherein the plants are grown in a substrate suspended above the ground and wherein the system comprises a control device and a fixture, the control device being adapted to supply a voltage to the fixture and wherein the fixture comprises a light emitting device with a plurality of LED light sources adapted to emit light when a voltage is applied; characterized in that the system comprises two or more luminaires, wherein a single driver is connected to the two or more luminaires and is adapted to apply the voltage to the two or more luminaires and wherein the driver is suspended from the substrate.

Modular greenhouse lighting system according to one of the preceding claims, wherein the control device is adapted to receive an alternating voltage from an electricity grid, to convert this alternating voltage into a direct voltage and to supply the direct voltage to the two or more luminaires.

3. Modular greenhouse lighting system according to one of the preceding claims, wherein each of the two or more luminaires comprises a luminaire housing comprising a first coupling element, the first coupling element being adapted to be coupled to a second coupling element of a different luminaire, so that a rigid coupling is formed between the luminaires and a substantially linear luminaire array of at least two luminaires is formed.

A modular greenhouse lighting system according to claim 3, wherein each of the two or more luminaires in the luminaire array comprises a first connector and a second connector and wherein the second connector of a first fixture can be connected to a first connector of a second fixture, so that a electrical connection between the luminaires in the luminaire array is established.

The modular greenhouse lighting system according to claim 4, wherein the first connector is arranged in the first coupling element and wherein the second connector is arranged in the second coupling element.

Modular greenhouse lighting system according to claim 4 or 5, wherein the control device is arranged to apply the voltage to the first connector of the first fixture.

The modular greenhouse lighting system of claim 6, wherein the voltage applied to the first fixture is transmitted to each of the fixtures in the fixture array through the connected second and first connectors.

A modular greenhouse lighting system according to any of claims 3-7, wherein the system comprises two or more luminaire rows.

The modular greenhouse lighting system according to claim 8, wherein the control device is arranged to apply the voltage to the first connector of the first armature of each of the armature rows.

The modular greenhouse lighting system according to any of the preceding claims, wherein the light-emitting device is arranged in an upper portion of each of the luminaires and wherein the light-emitting device is adapted to emit light in a substantially downward direction.

The modular greenhouse lighting system according to claim 10, wherein the system comprises at least one optical element, which is adapted to reflect at least a part of the substantially downwardly radiated light and to distribute at least a part of the light in a desired direction .

12. Modular greenhouse lighting system according to claim 11, wherein the light is diffused through the at least one optical element in desired directions which have an angle of between -120 ° and + 120 ° with respect to the substantially downward direction, in particular between - 105 ° and + 105 ° with respect to the substantially downward direction.

Modular greenhouse lighting system according to any of the preceding claims, wherein the intensity of the light emitted from the light-emitting device can be changed.

A modular greenhouse lighting system according to claim 13, wherein the control device is adapted to change the intensity of the light emitted by the light emitting device by changing the supplied voltage to the luminaires.

Modular greenhouse lighting system according to one of the preceding claims, wherein the luminaires are arranged to be suspended between the rows of plants.

A greenhouse, comprising a ceiling and at least one substrate, the at least one substrate being suspended from the ceiling, characterized in that the greenhouse comprises a modular greenhouse lighting system according to one of the preceding claims, wherein two or more luminaires are of the system suspended from the ceiling and wherein a control device of the system is suspended from the substrate.

A method of placing a modular greenhouse lighting system according to any of claims 1 to 15 in a greenhouse, the method comprising the steps of: providing a modular greenhouse lighting system according to claims 1-15; hanging the two or more luminaires from a greenhouse ceiling; suspending the control device from the substrate; and connecting an electrical cable with the control device and with the two or more luminaires.

The method of claim 17, wherein the method comprises the step of coupling the two or more fixtures to form a fixture array.