Classifications

• • 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
  • A01G9/246—Air-conditioning systems
• • 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
  • A01G9/14—Greenhouses
  • A01G9/1407—Greenhouses of flexible synthetic material
  • A01G9/1415—Greenhouses of flexible synthetic material with double or multiple walls
• • 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
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
  • Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
  • Y02A40/25—Greenhouse technology, e.g. cooling systems therefor

Definitions

• the present invention relates to greenhouses and more in particular closed greenhouses.
• the invention relates also to the use of such greenhouses for growing plants, distillation of seawater or brackish water, drying of goods or energy output.
• the invention relates further to a method to provide a closed greenhouse and a method for controlling the humidity and/or temperature in a greenhouse.
• greenhouses in very dry and arid environments usually lack sufficient fresh water for irrigating the crops and plants.
• salt seawater or brackish water is evaporated and condensed again, in order to provide fresh water.
• US4383891 or WO98/04231 describes such installations. Also these installations require significant investment and operational costs.
• Open greenhouses have been provided with systems to control the humidity and/or the temperature of the inner environment. Especially, much interest is shown in the control of the humidity of the inner environment of the greenhouse. Often temperature and humidity is controlled and adjusted by ventilating the greenhouse. But during ventilation, the CO 2 -content is not under control, especially not in the range being optimal for plant or crop growth.
• air conditioning systems conditioning the total volume of air present in the greenhouse, are used for controlling the humidity and/or temperature.
• air conditioning systems require again significant installation and consume a serious amount of energy. This causes significant operational costs during use of the greenhouse.
• the greenhouses may be used for several purposes, such as crop and plant growing, growing of aqueous plants such as seawater plants, or for providing fresh water from brackish or seawater, or for drying goods.
• the above objectives are accomplished by a greenhouse having a linking technical feature, namely that being the use of a water vapour permeable membrane as an additional layer in a solar still arrangement.
• a greenhouse comprises a floor surface and a building structure located above the floor surface.
• the floor structure and the building structure delimit an inner volumetric space.
• the building structure comprises at least one light- transmitting architectural element, which light transmitting architectural element is a double layered element comprising an outer layer of light-transmitting material and an inner layer of light-transmitting material, whereby a void space is provided between the inner layer and the outer layer.
• the greenhouse comprises means for extracting air from the void space.
• the inner layer is a water vapour permeable but water impermeable membrane, e.g. a polymer membrane.
• the light-transmitting architectural elements may be self-supporting or non-self-supporting elements. They may be rigid or flexible. These elements may be parts of or comprise architectural elements such as walls, roofs, windows, skylights. According to embodiments of the present invention, the building structure may consist of light-transmitting structural elements.
• a support fabric which is preferably mechanically coupled to the membrane, may be provided to support the membrane.
• the greenhouse further may comprise means for measuring the temperature and/or humidity of the inner space.
• the greenhouse further may comprise means for providing a gas such as ambient air to the void space.
• the greenhouse further may comprise means for heating and/or evaporating liquid in the inner space.
• this means for heating and/or evaporating liquid in the inner space may comprise liquid channels and/or liquid basins for exposing liquid to the environment in the inner space.
• Such means may be mounted on the floor of the greenhouse, or may be provided as channels or basins or alike, hanging in the inner space of the greenhouse.
• the environment includes sunlight.
• the means for heating and/or evaporating liquid in said inner space may comprise an irrigation system for irrigating the soil.
• the soil may be a part of the floor surface, or may be present in e.g. containers located in the inner space of the greenhouse.
• the greenhouse may be provided with a basin, which basin provides the floor surface of the greenhouse and functions as a means for heating and/or evaporating liquid in the inner space.
• the cultivation containers are mounted elevated from the floor surface in the inner space of the greenhouse.
• the greenhouse may comprise a heat exchanging means, the means for extracting air from the void space being coupled to this heat exchanging means for cooling the extracted air.
• the greenhouse further may comprise means for conducting at least part of this cooled air to the void space.
• the heat exchanging means may be a condenser for converting the air being extracted from the void space into condensate and dehumidified air.
• the greenhouse further may comprise means for conducting at least part of this condensate to the means for heating and/or evaporating liquid in the inner space.
• At least part of the condensate may be provided to the irrigating system.
• the greenhouse further may comprise means for providing secondary water to the heat exchanging means for converting the air being extracted from the void space into condensate and dehumidified air.
• this secondary water for exchanging heat with the air extracted from the void space may be stored in a water buffering means.
• the greenhouse further may comprise means for conducting at least part of the secondary water used for exchanging heat with the air extracted from the void space, to the means for heating and/or evaporating liquid in the inner space.
• the greenhouse may be a closed greenhouse.
• the greenhouse may be used for growing or cultivating plants, such as aqueous plants, e.g. aqueous plants which are grown in seawater.
• the greenhouse may be used for distillation of fresh water from secondary water such as seawater or brackish water, or may be used for drying goods and products.
• a method to modify a greenhouse comprising structural elements, a floor surface and at least one light transmitting member is provided. The method comprises:
• a water vapour permeable but water impermeable membrane e.g. a polymer membrane
• a double layered light transmitting architectural element which comprises an outer layer comprising the at least one light transmitting member, and an inner layer being the membrane.
• the double-layered light transmitting architectural element defines a void space between the inner and the outer layer.
• the double layered light transmitting architectural element and the floor surface encompasses an inner space;
• the light-transmitting architectural elements may be self-supporting or non-self-supporting elements. They may be rigid or flexible. These elements may be parts of or comprise architectural elements such as walls, roofs, windows, skylights.
• a method for controlling the humidity and/or temperature in a greenhouse comprises the steps of:
• the greenhouse as subject of the present invention comprises means for extracting air from the void space.
• the inner layer is a water vapour permeable but water impermeable membrane, e.g. a polymer membrane;
• the method may comprise the steps of:
• the greenhouse further may comprise a heat exchanging means.
• the void space is coupled to this heat exchanging means for cooling the extracted air.
• the method may comprise the step of providing at least part of the cooled air to the void space for adjusting the temperature and/or humidity of the air displaced in the void space in function of the monitored temperature and/or humidity of the air displaced in the void space.
• the method may comprise the step of mixing ambient air with this at least part of the cooled air to be provided to the void space according to a mixing ratio. The ratio may be adjustable in function of the monitored temperature and/or humidity of the air displaced in said void space.
• the heat exchanging means may be a condenser for converting the air extracted from the void space into condensate and dehumidified air.
• the greenhouse further may comprise means for conducting at least part of the condensate to the inner space of the greenhouse, e.g. for irrigating the plants and crops or for irrigating the soil in which the plants or crops are cultivated.
• the method may comprise the step of conducting at least part of this condensate to the inner space of the greenhouse for adjusting the temperature and/or humidity in the inner space in function of the measured temperature and/or humidity at the inner space as compared to the temperature set value and/or humidity set value.
• the greenhouse further may comprise means for heating and/or evaporating liquid in the inner space.
• the method may comprise the step of heating and/or evaporating secondary water in the inner space for adjusting the temperature and/or humidity in the inner space in function of the measured temperature and/or humidity at the inner space as compared to the temperature set value and/or humidity set value
• the greenhouse further may comprise means for providing secondary water to the heat exchanging means for cooling the extracted air from the void space.
• the method may comprise the step of providing at least part of this secondary water used for cooling the extracted air to the means for heating and/or evaporating liquid in the inner space. This in order to adjust the temperature and/or humidity of the air in the inner space in function of the measured temperature and/or humidity at the inner space as compared to the temperature set value and/or humidity set value.
• FIG. 1 is a schematically view of a first embodiment of a greenhouse as subject of the present invention
• Fig. 2 and Fig. 3 are schematically views of a second and a third greenhouse as subject of the present invention, which is provided by modifying a greenhouse according to a method of the present invention.
• the same reference signs refer to the same or analogous elements.
• water vapour permeable but water impermeable membrane is to be understood as a membrane, e.g. a polymer membrane, possibly a perforated membrane, which is permeable to water vapour, but which is substantially impermeable to water such as water droplets.
• the membrane may be permeable to water vapour due to osmosis effects, for example.
• secondary water is to be understood as any kind of water-based liquids such as seawater, brackish water, groundwater, waist water or even ordinary fresh or potable water.
• the secondary water is not necessarily useful directly for crop or plant cultivation. Description of illustrative embodiments
• first, second, third and the like in the description and in the claims are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.
• a device A coupled to a device B should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means.
• a greenhouse 100 comprises a floor surface 130 and a building structure 101 located above the floor surface and delimiting an inner space 102.
• the building structure comprises, and in this particular embodiment consists, of a light-transmitting structural element 103.
• the light light-transmitting structural element 103 has an inner surface 104 and an outer surface 105.
• the light light-transmitting structural element 103 is double layered, comprising an outer layer 106, e.g. being a water impermeable layer of bent plastic or glass, e.g. provided from polyester.
• the inner layer 107 is a water vapour permeable but water impermeable membrane, e.g.
• a polymer membrane e.g. an Osmofilm® membrane from the company ALYZEE (FR).
• a water vapour permeable membrane like Techpack membranes or Flecron membranes. It is preferred to use a membrane, which has a high permeability to water vapour.
• the permeability to water vapour is preferably more than 2 l/m 2 /24h, more preferred in the range of 7 to 20 l/m 2 /24h.
• the light-transmitting elements may be self-supporting or non-self- supporting elements. They may be rigid or flexible. These elements may be parts of or comprise architectural elements such as walls, roofs, windows, skylights.
• a means 109 for extracting air from the void space 108 e.g. a ventilator or a venturi-driven air mover, coupled to the void space by means of appropriate ducting system, is provided as shown in Fig. 1.
• This means 109 for extracting air is coupled to a heat exchanging means 110, e.g. condenser, for cooling the air being extracted from the void space 108 by means of means 109 for extracting air.
• the greenhouse further comprises a means 111 to provide ambient air into the void space 108, and means 112 to provide at least a part of the cooled and optionally dehumidified air, from the heat exchanging means 110 back to the void pace 108.
• a means 113 for discharging at least part of the air from said heat exchanging means to the ambient is provided.
• valve-like systems 114 are provided to control the amount of cooled air and/or the amount of ambient air and/or the ratio of ambient air and cooled air to the void space. It is understood that also only fresh air or only cooled air may be directed or redirected to the void space by these valve-like systems 114. Air, either fresh ambient air or cooled or dehumidified air is to be provided to the void space, in order to avoid a too large a sub-pressure in the void space 108. Such significant sub-pressure could harm the membrane 107
• the means 109 for displacing air in the void space 108 is not coupled to a heat exchanging means, the means 109 for displacing air may discharge its air taken from the void space to the ambient. It is understood that in such case, sufficient fresh ambient air will have to be provided to the void space 108 by means of means 111 to provide ambient air into the void space 108, in order to avoid e.g. a significant sub- pressure in the void space 108 as compared to the pressure in the inner space 102.
• the heat exchanging means 110 is a condenser, as shown in
• the cooled air will be dehumidified air.
• the condensate this is the condensed water from the condenser, is fresh water and may be stored in a buffer unit 115. It may be brought back, at least partially, to the inner space 102 of the greenhouse 100, e.g. to irrigate the soil 131 onto which the crops and plants are grown in the inner space 102 of the greenhouse. At least part of the condensate can be used to provide water to an irrigation system 132, which irrigation system 132 forms part of a means for heating and/or evaporating liquid in the inner space 102.
• the greenhouse may be seen as a source to provide fresh, e.g. potable, water. At least a part of the condensate, which is not used to irrigate the soil, may be used to provide potable water or fresh water. The provision of such fresh water is an advantage when the greenhouse is located in regions where there is a shortage of fresh water.
• a heat exchanging means 110 such as a condenser
• a heat exchanging means 110 such as a condenser
• several possible fluids may be used to cool the air.
• secondary water such as seawater, brackish water or ground water may be used.
• means 116 to provide secondary water to the heat exchanging means 110 is provided.
• This means 116 may comprise a buffer volume 117.
• the secondary water, or at least a part of this secondary water, being heated by the heat exchanging means 110 can be provided to either a means 118 for heating and evaporating this secondary water in the inner space 102 of the greenhouse 100.
• the water, or at least a part of this water, being heated by the heat exchanging means 110 may be conducted back to said buffer volume 117 via appropriate conducting means 119, or may be discharged back to the ambient (not shown in Fig. 1). It is understood that appropriate valve-like systems 120 may be provided to adjust the volumes of water to be conducted to various directions.
• the means 118 for heating and/or evaporating liquid in the inner space 102 may comprise liquid channels 133 or liquid buffers, which expose the liquid to the environment of the inner space.
• separate buffers may be used, one for cold water to be used for cooling the extracted air in the heat exchanging means, and another one for recovering the water which is pre-heated in the heat exchanging means.
• This pre-heated water may be used to cool the air introduced into the void space.
• the amount of air being extracted in the void space the amount of air being extracted over night can be reduced. This may create an insulating air layer, which prevent the inner space to cool down too quick or too much during night.
• the void space functions as a thermal insulating layer.
• the water, or at least a part of this water, being heated by the heat exchanging means 110 and being conducted back to said buffer volume 117 may be used to keep the water in the buffer volume at a constant or increased temperature. This may be an advantage during nighttime, when no sunlight is available for heating the air in the void space 108. As the ambient air may cool down too much, the buffer volume may be used during this period to keep the air circulated in the void space 108 at the temperature above the ambient.
• the water in the buffer volume 117 can be used as a source of thermal energy. This thermal energy may be provided to the air extracted from the void space by e.g. the heat exchanging means, when being used in a reverse way: the air being heated by the water, instead of air being cooled by the water.
• the means 112 to provide cooled air from the heat exchanging means 110 back to the void pace 108 may have an extra heat exchanging region 123 in the buffer volume 117, as well as a bypass 124 to bypass this extra heat exchanging region 123. It is understood that a valve-like system 125 may be provided to adjust the amount of air being provided to either the extra heat exchanging region 123 or the bypass 124.
• means 121 for conducting secondary water directly to the means 118 for heating and evaporating liquid in the inner space 102 of the greenhouse 100 is provided. It is understood that appropriate valve-like systems 122 may be provided to adjust the volumes of water conducted to the inner space 102 by means 121.
• the membrane may be provided with a support fabric, which is sufficiently light transmitting in order not to cause a negative effect on the ratio of illumination of the crops or plants being grown in the inner space102, and/or to avoid too much negative effect on the yield of water being evaporated or heated in the inner space.
• a woven, non-woven or knitted fabric e.g. from polymer such as transparent polymer filaments, may be mounted under the membrane.
• a fabric may e.g. be mechanically coupled to the membrane, such as by laminating the fabric to the membrane.
• a support fabric may be provided which shields a part of the light.
• a black woven or non-woven fabric may be used as support fabric.
• a semi-transparent fabric may be provided, e.g. a black gauze woven or non-woven fabric, which fabric shields the crops and plants form at least a part of the illumination.
• This fabric located between inner side of membrane and crops prevent the crops to be subjected to too high degree of illumination, meanwhile allowing the light energy to heat the air of the inner space above the fabric.
• the fabric may be provided with a selectively light reflecting coating, reflecting light back to the space above the fabric and into the void space. This reflected light might further heat the air in the inner space above the fabric and the void space.
• the means 118 for heating and/or evaporating liquid may be provided as liquid channels or basins.
• means for increasing the temperature of the liquid and to increase the yield of evaporation may be provided, such as e.g. the inner surface of the channel or basin may be coloured black.
• waves may be created in the liquid present in the basins or channels.
• means to create and guide air bubbles through the liquid may be provided.
• means to create liquid movement or fountains in the liquid may be provided.
• the liquid basin or channel may be covered with a water vapour permeable membrane, similar or identical to the membrane of the inner layer 107.
• Fig. 2 shows an alternative embodiment of the present invention.
• the greenhouse 200 is based on an existing conventional greenhouse structure.
• the existing greenhouse comprises structural elements 203, e.g. brick walls, on which a construction of light transmitting members is provided, e.g. made of glass or plastic. It is understood that the existing greenhouse structure will further comprise supporting means, frame work for holding the glass, plastic or any other useful light transmitting structure, such as profiled metal bars and many more structural elements to provide a firm greenhouse structure.
• Such an existing greenhouse structure can be modified, according to an object of the present invention, into a greenhouse 200 as subject of the present invention.
• a method is provided to modify a greenhouse comprising structural elements 203, a floor surface and at least one light-transmitting member, comprising the steps of
• a water vapour permeable but water impermeable membrane e.g. a polymer membrane
• a double layered light transmitting architectural element 103 which comprises an outer layer 106 comprising at least one light transmitting member, and an inner layer 107 being said membrane.
• the double-layered light-transmitting architectural element 103 defines a void space between the inner and the outer layer.
• the double layered light transmitting architectural element 103, the floor surface 204 encompasses an inner space.
• Fig. 1 may be provided, in order to create an alternative greenhouse 200 as subject of the present invention.
• Identical reference numbers for means shown in Fig. 2 refer to identical means as described and explained in Fig. 1 , and have the same function and provide the same advantages as was explained for the features in Fig. 1.
• Fig. 3 shows an alternative for the greenhouse as shown in Fig. 2.
• the greenhouse is provided with an additional discharging means 301 for discharging secondary water being used by the heat exchanging means 110.
• the greenhouse comprises also an additional means 302 for guiding cooled air through the heat exchanging means.
• the means 302 provides the possibility to cool the extracted air to even lower temperatures.
• the conducting means 119 and 121 are provided as one duct 303.
• the valve-like systems 120 and 122 are provided as a mixing valve 304.
• the greenhouse is provided with a semi-transparent fabric 310, e.g. a black gauze woven or non-woven fabric, which fabric shields the crops and plants form at least a part of the illumination.
• a semi-transparent fabric 310 e.g. a black gauze woven or non-woven fabric, which fabric shields the crops and plants form at least a part of the illumination.
• Further means 311 are provided to introduce additional water vapour or water in the void space, to further lower the temperature of the air in the void space and thus in the inner space.
• this means 311 comprises a sprinkler 312 system.
• the buffer unit 115 is provided with a discharging means 313 for allowing condensate to be discharged from the water circuit.
• This condensate discharged via means 313 may be used for other applications, e.g. to produce potable water or alike.
• Identical reference numbers for additional means shown in Fig. 3 refer to identical means as described and explained in Fig. 1 and Fig. 2, and have the same function and provide the same advantages as was explained for the features in Fig. 1 and Fig. 2.
• the devices for conditioning e.g. cooling or dehumidifying the air, e.g. the heat exchanging means
• the modification of an existing greenhouse can be made at relatively low investment costs.
• the devices, which are to be provided to modify the existing greenhouse are fairly easy in use and can easily be adjusted and controlled.
• the modifications of the existing greenhouse into a greenhouse as subject of the present invention provide significant advantages. Whereas the existing greenhouse may have to be ventilated completely when the temperature in the inner side of the greenhouse was increased too much, the inner space of the modified greenhouse 200 is not to be ventilated.
• the temperature and humidity of the inner space can be set and controlled to a given level in such a way that even when too much light or solar energy is provided to the greenhouse, the CO 2 -content, humidity and temperature conditions in the inner space can be kept in optimal conditions to have the largest yields of crop or plant growing.
• the additional solar energy available can be converted into fresh water of thermal energy stored for use over night or during periods where less solar energy is available.
• the modification of the existing greenhouse according to the present invention has as an advantage that the amount of light, which can be used to grow the crops or plants, is not to be significantly reduced.
• the greenhouse comprises a means for heating the environment in the inner space in case the temperature is too low, and the amount of illumination by solar energy is not sufficient to heat the inner space sufficiently.
• the void space between the inner and outer layer of the light transmitting structure element can still be used to evacuate superfluous vapour, and/or can function as a thermal buffer between ambient and inner space, avoiding to some extent thermal losses of energy.
• the greenhouses 100 and 200 as shown in Fig. 1 and Fig. 2 can be used as a closed greenhouse. According to the third object of the present invention, a method for controlling the humidity and/or temperature in a greenhouse as subject of the present invention is provided.
• the temperature, humidity and CO 2 -content present in the inner space can be controlled without the need to ventilate the whole inner space e.g. to control the temperature.
• the whole volume of air present in the inner space of the greenhouse as subject of the present invention is not to be displaced and treated, e.g. cooled or heated, to adjust its temperature, humidified or condensed to adjust its humidity.
• the water vapour permeable but water impermeable membrane e.g. a polymer membrane
• the CO 2 -content of the inner space can easily be controlled by providing once a sufficient amount of CO 2 to create a given concentration of CO 2 , and thereafter only adding the amount of CO 2 , which is consumed by the crops or plants being grown.
• the amount of CO 2 may be provided by composting of e.g. wet peat in the inner space.
• the temperature and humidity of the air in the inner space of the greenhouse can be controlled by
• the temperature and/or humidity of the air being displaced in the void space is monitored, and the amount of air extracted from the void space is changed in function of the monitored temperature and/or humidity of said air displaced in said void space.
• the additional means as disclosed and described in Fig. 1 and Fig. 2 may be provided.
• the greenhouse may comprise a heat exchanging means, e.g. a condenser, which is coupled to the void space for cooling the extracted air, or in case of a condenser, converting the extracted air into condensate and dehumidified air.
• the cooled or dehumidified air may be provided again to the void space for adjusting the temperature and humidity of the air displaced in the void space.
• the method comprises the step of mixing ambient air with at least part of the cooled air or dehumidified air to be provided to the void space according to a mixing ratio, which ratio being adjustable in function of the monitored temperature and/or humidity of the air displaced in the void space.
• the greenhouse further may comprise means for conducting at least part of the condensate to the inner space of the greenhouse
• the method as subject of the present invention may comprise the step of conducting at least part of the condensate to the inner space of the greenhouse for adjusting the temperature and/or humidity in the inner space in function of the measured temperature and/or humidity at the inner space as compared to the temperature set value and/or humidity set value.
• the greenhouse further comprises means for heating and/or evaporating liquid in said inner space.
• the method may comprise the step of heating and/or evaporating secondary water in the inner space for adjusting the temperature and/or humidity in the inner space in function of the measured temperature and/or humidity at the inner space as compared to the temperature set value and/or humidity set value.
• the greenhouse further comprises means for providing secondary water to the heat exchanging means for cooling the extracted air from the void space.
• the method may comprise the step of providing at least part of the secondary water used for cooling the extracted air to the means for heating and/or evaporating liquid in the inner space for adjusting the temperature and/or humidity of the air in the inner space in function of the measured temperature and/or humidity at the inner space as compared to the temperature set value and/or humidity set value.
• the humidity at the inner space can be controlled by controlling the water vapour pressure of the air in the void space, in function of the water vapour pressure in the inner space.
• the difference between these two water vapour pressures at both sides of the membrane defines the amount of vapour being transferred between the two sides of the membrane, taking the surface area of the membrane into account. This is because the water vapour passes through the membrane from the side at with there is a higher water vapour pressure to the side where a lower water vapour pressure is present.
• the water vapour pressure at the inner space will be higher as compared to the water vapour pressure in the void space, which two spaces are separated by the water vapour permeable membrane. So water vapour will pass from the inner space to the void space.
• the illumination of the greenhouse by means of sunlight increases the temperature of the inner space and the void space.
• Crops or plants present in the inner space will provide water vapour to the inner space. Also water evaporated from the soil will provide water vapour to the inner space. Other liquids such as secondary water present in the inner space, such as by means of liquid channels or basins will partially or fully evaporate providing water vapour in the inner space. The surface and the temperature of the liquid such as secondary water will influence the amount of water vapour provided in the inner space.
• the water vapour pressure at the inner space will be higher as compared to the void space.
• Water vapour will pass from the inner space to the void space through the membrane.
• the amount of air extracted from the void space, the amount of plants and crops, the amount of water in the soil, and the amount and optionally the temperature of water evaporating at the inner space allow to adjust the water vapour pressure present over the membrane, and thus the amount of vapour to be extracted from or provided to the inner space.
• the humidity, and to some extent the temperature, of the inner space will be controlled by the water being evaporated in the inner space.
• the temperature of the inner space which is influenced by the amount of solar illumination provided to and through the light transiting structure elements, can be controlled by several parameters, dependent on the means provided to the greenhouse as subject of the present invention.
• the temperature of the inner space can be controlled by varying and adjusting the amount and temperature of the air extracted from the void space It may as well be influenced by controlling the amount and temperature of the liquid, either condensate or secondary water, either from the heat exchanging means, from the buffer volume and/or from the ambient, being provided to the inner space for evaporation.
• the temperature of the air in the void space can be controlled by controlling and adjusting the temperature and volume of air being provided to the void space, either ambient air or cooled and/or dehumidified air. It may also be controlled and adjusted by changing the amount of air extracted from the void.
• the temperature is to decrease in the inner space, e.g. when too much sunlight is provided to the greenhouse, more water may be evaporated, as the evaporation consumes thermal energy, being provided to the inner space via the illumination.
• the amount of thermal energy consumed can be further increased e.g. by enlarging the water surface present in the inner space, or by creating water movement or fountains in the water to be evaporated or similar actions, which increase the amount of liquid which is evaporated.
• condensate is used to irrigate the soil of the greenhouse, more condensate may be provided to increase the amount of condensate that is evaporated.
• the temperature of the air circulating in the void space can be reduced, e.g.
• the heat exchanging means by cooling the air in the heat exchanging means to a lower temperature by using more or colder water at the cold side of the heat exchanging means, or by changing the ratio of ambient air and cooled air from the heat exchanging means to provide air entering in the void space at a lower temperature.
• the amount of air extracted from the void space can be increased as well.
• means are provided in the void space to introduce additional water vapour or water in the void space, to further lower the temperature of the air in the void space and thus in the inner space.
• a sprinkler system or alike may be provided. If the air extracted from the void space is condensed to condensate in the heat exchanging means, which condensate is used to provide fresh or even potable water, it is understood that the water vapour provided by such system in the void space is to be fresh water.
• the liquid to be evaporated in the inner space may be provided on a higher temperature, this is especially the case when substantially no illumination is provided, e.g. over night.
• the amount of liquid to be evaporated may be decreased, or the temperature of the air in the void space may be increased. Alternatively, the amount of air extracted from the void space may be reduced.
• the greenhouses as subject of the present invention, and especially closed green houses as subject of the present invention have further advantages.
• the membrane is impermeable for bacteria.
• the bacterial content present in the inner space can then be easily controlled. This is advantageous because the crops and plants can be shielded from endangering bacteria.
• the energy sources such as motors for driving different means for displacing fluids such as the water of the air, can be generated by using solar energy.
• the buffer unit storing the condensate may be positioned higher than the ground level in the inner space of the greenhouse, in order to facilitate an easy irrigation, using a minimum of energy. Because the humidity of the inner space can be kept high, there is less irrigation water needed to grow crops or plants.
• the secondary water may be subjected to evaporation to such an extent that only a dry residue, e.g. salt in case of seawater, remains, or a means for discharging water from the means for heating and/or evaporating liquid in said inner space to the ambient or to the buffer volume may be provided.
• a dry residue e.g. salt in case of seawater
• a means for discharging water from the means for heating and/or evaporating liquid in said inner space to the ambient or to the buffer volume may be provided. The latter to discharge the partially evaporated liquid
• a protective means such as a semitransparent or not transparent cover or shield may be provided to prevent a part of the solar energy to illuminate the greenhouse.
• the greenhouse as subject of the present invention may provide a significant reduction of energy consumption. A reduction of about 60% as compared to the presently known greenhouses may be obtained.
• the greenhouse may create energy which can be used, as set out above, to distillate seawater or brackish water.
• the greenhouse can hence be seen as a collector of solar energy, which converts substantially all solar energy being provided to the greenhouse. In the first place it converts solar energy to provide an increased yield of crop growth by controlling the temperature, humidity and CO 2 -content of the inner space of the greenhouse.
• the surplus of solar energy is used either to provide fresh water, e.g. for irrigation of the crops, or is buffered and stored for use when insufficient solar energy is available, or for other uses.
• the optimal control of temperature, humidity and CO 2 -content according to the present invention doesn't need the whole air volume of inner environment of the greenhouse to be circulated, which circulation itself may influence or even endanger the cultivation of certain crops or plants. It is understood that the temperature, humidity and CO 2 -content may be varied in time, in order to influence the moment of harvest of crops in the greenhouse.
• the greenhouses as subject of the present invention may be used for several applications.
• the greenhouses as shown in Fig. 1 and Fig. 2 may be used for growing crops and plants.
• the greenhouse may be used to grow aqueous plants, such as e.g. plants grown in seawater, when seawater is evaporated and/or heated.
• the greenhouses may be used to dry products, such as fruit, vegetables, grains, organic waist, sludge or any other water-containing substrate.
• the means to means for heating and/or evaporating secondary water in the inner space of the greenhouse are not necessarily to be provided.
• the ambient air is sufficient to provide a sufficient water vapour pressure over the two surfaces of the membrane, the heat exchanging means is not necessary either. The air taken from the void space, which is replaced by fresh ambient air, can be discharged to the ambient.

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• 2006
  • 2006-01-12 EP EP06701319A patent/EP1981330A1/de not_active Withdrawn
  • 2006-01-12 WO PCT/EP2006/000219 patent/WO2007079774A1/en active Application Filing

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