High energy efficiency air handling system for temperature and humidity management in an enclosure

Abstract

Air handling system for the modulating regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment, characterized in that it comprises: - a combined heating and cooling unit (1) - a plurality of air handling units (3), each enclosure (2) being equipped with at least one air handling unit (3); - each air handling unit (3) comprising: o an air handling unit (30) o at least one heat exchanger (52) o hydraulic components for connection with the heating and cooling unit (1) and the components of the air handling unit (30);o at least one control unit for said hydraulic components of the means for controlling the flow and temperature of the air in the air handling unit (30) and of the means for controlling the flow and temperature of the water in the air conditioning components of said unit (30). [FIG1.];

Description

Title of the invention: High energy efficiency air handling system for temperature and humidity management in an enclosure

[0001] The present invention relates to the field of air treatment, and more particularly to an air treatment system for managing the internal climatic conditions of an enclosure, specifically controlling the temperature and humidity of the air within that enclosure. These parameters must be able to be precisely controlled, both upwards and downwards, according to requirements specific to the objectives assigned to the enclosure, particularly with a view to reducing energy consumption.

[0002] The application context in this case is the production of plants in a controlled environment, specifically in enclosures that allow for such production because they define a space suitable for maintaining a controlled atmosphere. These enclosures are, very schematically, equipped with actuators and sensors that allow for the regulation of a number of parameters such as air temperature, air humidity, gas flows (air, CO2, etc.), the degree of irrigation, the quantity of nutrients supplied to the plants being grown there, etc. Among these parameters, air temperature and humidity are fundamental because they contribute more than others to the conditions for the harmonious development of the cultivated plants.

[0003] The major challenge of closed-loop thermal regulation in this context concerns the management of latent heat loads. Indeed, since crops emit large quantities of water vapor through evapotranspiration (more than 80% of the water supplied by irrigation is released in this form), it is necessary to remove this water from the ambient air to maintain a constant humidity level, through dehumidification. The invention aims to provide an air treatment solution capable of containing this water within the system, which is then recovered (through condensation) for reuse in irrigation, thus offering a drastic reduction in the water consumption required for the crop, while limiting the amount of energy needed to recover this water vapor.

[0004] Among the objectives of the invention, particularly for the continuous management of the aforementioned parameters, the energy aspect has been mentioned, which can be further specified by indicating that the aim is to use a minimum of energy to manage the widest possible operating range. The system must be able to benefit from a wide range of use, in terms of temperature and humidity, regardless of The thermal loads and stresses that also result from the typical operation of this type of installation, such as lighting power, plant transpiration, etc., must be considered. However, the possibility of a wide operating range must not come at the expense of the precision of the regulation of the aforementioned parameters, which must remain stable and consistent.

[0005] In practice, the invention is such that it makes it possible to keep the minimum operating energy at every point of operation of the system, including under partial load, which notably implies the creation of hydraulic circuits - in particular for the production of cold and heat - which are free as much as possible from the pressure losses related to their constituent components and which minimize the heat transfers to be made to compensate for the (sensible and latent) loads emitted into the environment, namely mainly the water vapor emitted by the plants and the heat released by the artificial lighting used for cultivation.

[0006] Known systems, particularly those used for closed-loop air conditioning based on thermodynamic dehumidification, often suffer from low energy efficiency. This is the case, for example, with so-called "split" gas air conditioning systems combined with a dehumidifier, which result in a size that can be considered prohibitive for the enclosures covered by the invention, and which also release heat into the space, necessitating complex temperature control. Furthermore, these systems present a risk of icing at low temperatures and high relative humidity. Water chiller and heat pump systems also do not have a high overall energy coefficient of performance (COP) because they require independent production of cooling and heating, resulting in redundant electricity consumption.

[0007] Conventional air handling units are not suitable for a controlled atmosphere environment because they do not allow for closed-loop production, as this leads to losses of water and CO2. Indeed, their operating principle requires air renewal, the energy and economic balance of which is not always favorable compared to the previously mentioned closed-loop technologies.

[0008] Dehumidification systems using an alternative technique, such as desiccant wheel adsorption, require a high-temperature heat source for regenerating the adsorbent medium, which generally necessitates the use of a fossil fuel (such as natural gas) for combustion. Furthermore, these techniques present a significant risk of water contamination and generally do not allow for the recycling of the collected water. Finally, they require to have another means for temperature regulation which multiplies the air conditioning devices and thus the costs and the space required.

[0009] As for known regulation techniques, modulation by thermostat and hygrostat leads to very low precision and significant variations in relative pressure / volume variables, not allowing for optimized operation, at least not to the extent required to operate an enclosure of the type concerned by the invention which requires a fluctuation limited to a few tenths of degrees Celsius and percentages of relative humidity.

[0010] Contrary to the objective of achieving a wide operating range, with optimization possible across its entire width, known solutions that ensure stability—for example, modulation using 2- or 3-way valves—only allow control of the water flow rate or temperature over a limited range, without the possibility of optimization across the entire temperature and humidity range. This often leads to contradictory control strategies, such as the need to mist water to compensate for excessive latent power, due to the inability to control the ratio between sensible and latent power delivered by a main heat exchanger (such as a chilled water coil).

[0011] The present invention addresses these shortcomings by implementing, in a combined manner, a high-performance air handling system, efficient heating and cooling production, and thermal management aimed at optimizing fluid circulation (flow rate and temperature of the air and water circulating in the system) throughout the entire installation. The system of the invention aims to ensure a robust compromise between achieving climate setpoints (temperature and humidity) and the energy consumption of the hydraulic system components (pumps, fans, compressors), while resolving the contradiction imposed by existing systems that require a choice between high energy consumption or, alternatively, the loss of water and CO2 present in the growing system through air renewal.

[0012] To this end, the air treatment system of the invention, more particularly designed for the adjustable regulation of temperature and humidity in a plurality of plant production enclosures in a controlled environment, is such that it comprises:

[0013] - a combined heating and cooling unit comprising a heat pump heat, a hot water distribution circuit and a cold water distribution circuit;

[0014] - a plurality of air handling units, each enclosure being equipped with minus one processing plant;

[0015] - each air handling unit comprising:

[0016] O an air handling unit having two openings leading into the interior of the enclosure and two openings leading out of the exterior of the enclosure, air conditioning components, fixed internal partitions and movable partitioning means cooperating with the fixed partitions and walls of the unit to delimit at least one air conditioning circuit in the unit, each circuit comprising an air inlet opening, at least one fan directing the airflow and an air outlet opening, said air inlet and air outlet openings of the circuit being two of the four openings leading into the interior and out of the enclosure;

[0017] O at least one heat exchanger allowing the recovery of thermal energy from the outside air, capable of using the outside air as a source of thermodynamic energy in order to achieve the heating, cooling or dehumidification of the inside air without exchange of air between the inside and outside of the enclosure;

[0018] O hydraulic components for connecting the hot and cold water distribution circuits of the heating and cooling unit and the components of the air handling unit;

[0019] O at least one control unit of said hydraulic linking components connected to at least one sensor of at least one air parameter in the enclosure;

[0020] O means for controlling the flow and temperature of the air in the air handling unit and means for controlling the flow and temperature of the water in the air conditioning components of said unit.

[0021] The invention is therefore based on a combined heating and cooling unit whose distribution circuits are connected to the air handling units of each enclosure. At all levels, control devices allow for real-time measurement of the system's operating conditions, so that one or more processing and control units receiving these measurements can select, according to algorithms specifically designed for this system, the actions to be taken to best regulate the air conditioning of the production enclosures.In other words, the invention combines a high-performance air handling system capable of using outside air as an energy source without air exchange, efficient heating and cooling production, and thermal management aimed at optimizing the circulation and state of fluids (including, for example, flow rate and temperature) in the system to ensure the best compromise, continuously, between meeting climate setpoints (mainly temperature and humidity) in the enclosures and energy consumption by the system components (pumps, fans, compressors).

[0022] The implementation of this combined architecture allows for a wide operating range of climatic parameters, regardless of the system's thermal loads. It also leads to high control accuracy, notably producing stability and homogeneity of the climatic parameters managed by the system. Finally, energy efficiency is significantly increased compared to known systems, resulting in minimal energy consumption at any operating point (including under partial load). Due to the proposed configuration, the invention largely eliminates the pressure losses necessary to balance a large network with numerous branches (at the valves, pressure relief valves, etc.). System optimization is multifaceted and also incorporates the consideration of heat emissions, insofar as it prevents heat input into enclosed spaces.

[0023] Preferably, according to the invention, the movable partitioning means may comprise, on the one hand, at least one partially retractable partition capable of separating a first space having two openings leading to the outside of the enclosure from a second space having two openings leading to the inside of the enclosure, and on the other hand, at least one partially retractable partition capable of separating the openings of the same space. Thus, it is possible to adapt the operating mode of the air handling unit to the internal conditions (operating range of the thermal regulation) and external conditions (surrounding climatic conditions), in order to choose the configuration offering the best compromise in terms of energy consumption, at any time of year and according to the geographical location of the plant production facility.

[0024] The operational regulation mentioned earlier therefore concerns not only the control components such as sensors for the climatic parameters tested during the process, or the software units for processing these parameters, or even the actuator components for coupling the various hydraulic circuits (valves) and their management programs, but also the possibility of configuring the processing circuits for said climatic parameters in several ways, so as to optimize the implementation of the components best suited to each situation. Changes made to the circuits are achieved via movable partitions whose positions can be modified, as can their degree of closure if it is necessary to partially use passageways.

[0025] According to a preferred configuration, allowing for the implementation of changes to the air handling circuit under optimal conditions, the air inlet opening of the first space is provided coaxial with the air outlet opening of the second space, and the air outlet opening of the first space is provided coaxial to the air inlet opening of the second space. In this hypothesis, the two spaces are configured in a way in opposition and in extension of each other, and it is easy to modify the location of the mobile partitioning means to change the nature and arrangement of the hydraulic air treatment circuits.

[0026] More specifically, the first space may include a fixed internal partition dividing it into two parallel corridors opening into the openings of said first space and connected to each other, near a partition wall that is at least partially retractable, by means of a movable partition. In this design, a first corridor opening into the air inlet may, according to the invention, include a fan and a heat exchanger. The first space has a U-shaped volumetric configuration, with the possibility of opening or closing the air passage between the two corridors at the base of the U.

[0027] Similarly, the second space may also include a fixed internal partition dividing it into two parallel corridors opening onto the openings of said second space and connected to each other, near a partition wall that is at least partially retractable, by means of a movable partition. Again, a first corridor opening into the air inlet may include a fan and a heat exchanger positioned downstream of the fan. This heat exchanger is either connected by a pipe carrying a heat transfer fluid to the heat exchanger of the first space, or formed of regularly spaced fins so that the air from the first and second spaces circulates interspersed between these fins, allowing for sealed heat exchange, with the airflows crossing without ever mixing.In this configuration, the second corridor can include a cooling coil, a heating coil, and a humidifier proximal to the air outlet opening.

[0028] The relationship between the heat exchangers of the first and second spaces allows for manipulation of the temperature difference between the outside and inside air, and, for example, for extracting heat / cooling from the outside air and transferring it to the inside air (or vice versa) using the heat transfer fluid. This allows for sensible and latent heat transfer without air exchange, thus without impacting all the climatic parameters. Therefore, the outside air contributes, as appropriate, to heating, cooling, and / or dehumidifying the inside air, thereby reducing the need for a refrigeration or heating unit (and thus the associated electricity consumption) to perform this heat exchange necessary for climate control within the enclosure.

[0029] The mobile partitioning means allow the nature of the circuits to be changed by means of a physical change in configuration, depending on the presence or absence of partition walls, which may be retractable. Thus, the following configurations can, for example, be implemented:

[0030] - the two spaces are separated by a watertight central partition, and the two corridors from each of the two spaces are connected;

[0031] - the inlet opening of the first space is connected to the outlet opening of the second interior space within the enclosure, and the entrance opening of the second space is connected to the exit opening of the first space leading to the outside of the enclosure, the two corridors of each space are separated by a watertight partition;

[0032] - the two spaces are separated by a watertight central partition, and the two corridors The first space connected to the outside air is separated by a sealed partition;

[0033] - the two corridors of the first space connected to the outside air are separated by a airtight partition, and the partitions between the two spaces and the partition between the two corridors of the second space connected to the air inside the enclosure are at least partially retracted.

[0034] All these distinct configurations allow for different operating modes, which will be explained in more detail later. It is immediately clear, however, that the airflow and exchange they allow are likely to significantly alter the climatic parameters inside each enclosure. This, combined with the precise management of the system's climatic and hydraulic components, enables different operating modes that optimize energy consumption and heat and gas exchange between the inside and outside of each growing chamber.

[0035] The components, actuators, etc., are themselves, as already mentioned, managed by processing means coupled to sensors so that, within the climatic chambers, all these components ensure the regulation of the system by optimizing its operating point at every moment according to the objective pursued. In practice, in the second space connected to the chamber's interior air, the cooling coil includes at least one air / water heat exchanger for cooling and dehumidification connected to the cold water distribution circuit, and the heating coil includes at least one air / water heat exchanger for heating connected to the hot water distribution circuit. These connections to the hot and cold water distribution circuits themselves include components for adjusting to the desired operating conditions.

[0036] More specifically, according to the invention, the hydraulic components connecting the hot and cold water distribution circuits of the refrigeration production unit and heat, and the components of the air handling unit's casing for each air handling unit may include:

[0037] - in a connecting pipe to the cold water distribution circuit, a valve three-way valves and a recirculation pump controlled by a control unit linked to the air handling unit; and

[0038] - in a connecting pipe to the hot water distribution circuit, a valve two lanes controlled by said control unit.

[0039] Preferably, the three-way valve, the recirculation pump and the two-way valve are controlled proportionally, proportional control being understood as opposed to an "on or off" control: this means that the opening of the valve and the flow rate / rotation speed of the pump are modulated between 0 and 100% of their maximum value, which implies a possibility of total modulation.

[0040] The air / water cooling and dehumidification exchanger has individualized air and water flow and temperature control for each culture chamber, with regulation carried out via the control unit of the invention, which is based on at least one management algorithm specific to the invention. These algorithms control, in particular, the circulation pump (flow rate, temperature differences) and the 3-way regulating valve (adjusting the water temperature at the inlet of the cooling coil) in order to optimize the operating point of the air conditioning system according to sensible and latent loads and the required climate setpoints.The control systems manage the various components, seeking an optimum through an algorithm designed to position the cooling coil at the optimal point in terms of the sensible power / latent power ratio. This is achieved by varying the combined flow rate of the water in the cooling coil, the temperature of the incoming cold water, and potentially the air temperature. Consequently, the need for supplementary heating or misting is limited, minimizing cooling power consumption and water input into the enclosure. This ensures dehumidification at the lowest energy cost while reducing water requirements. The air-to-water heating heat exchanger, connected to the heating and cooling unit, for example via a two-way valve, utilizes total heat recovery to limit the heat pump's energy consumption.

[0041] In the system of the invention, upstream, the hot water distribution circuit of the heating and cooling unit includes at least one water pipe connected by an exchanger to the condenser of the heat pump, and the cold water distribution circuit includes at least one water pipe connected by an exchanger to the evaporator of the heat pump.

[0042] According to a specific aspect of the invention, the heat pump used actually comprises at least one external evaporator-condenser connected to an external heat source, consisting of a heat exchanger with two independent cooling and heating circuits sharing the same chiller. This configuration allows for the fully controllable removal of either excess heat or excess cold to ensure minimal energy consumption (compressor, fan and pump rotation) by utilizing both the cold and hot sources of the thermodynamic circuit represented by the heat pump, thus avoiding redundant electricity consumption associated with the use of two separate heat pumps.

[0043] This is in fact a thermodynamic heat pump circuit allowing the combined, independent and optimized production of cold and heat, making it easy to dose the power exchanged not only with the downstream cold or hot water distribution circuits, but also with the outside (excess cold or heat rejection).

[0044] The heat pump of the cold and heat production unit includes means for controlling the operation of the evaporator-condenser respectively as an evaporator or as a condenser, said control means including means for processing the demand for hot water or cold water by the air handling units of the culture chambers.

[0045] The operating principle is as follows: when the primary demand is for cooling, the circuit modulates the compressor speed and the expansion to the evaporator to deliver the required cooling capacity on the distribution side. Depending on whether or not there is a heating demand on the distribution side, the circuit modulates the condensation between the outdoor evaporator-condenser (operating in condenser mode) and the condenser on the hot water distribution circuit side in order to dissipate all excess heat. When the primary demand is for heating, the reverse occurs: the circuit adjusts the power delivered for hot water distribution and arbitrates the expansion between the cooling side and the outdoor unit (which then operates in evaporator mode) to dissipate all excess cooling.The switch from one mode to another is gradual, without interrupting the operation of the compressor or reversing the direction of fluids in a circuit, thus avoiding the use of a reversing valve, and resulting in improved reliability and a reduced risk of leakage.

[0046] It should be noted that the external evaporator-condenser(s) can be integrated into the machine or located remotely. Furthermore, it should be noted that the external evaporator-condenser(s) can be connected to the compressor circuit by a direct connection (the refrigerant being that circulating through the compressor), or via a heat exchanger, allowing the use of a different fluid between the compressor circuit and that of the external evaporator-condenser(s). such as CO2 or other refrigerant for the first and water for the second, thus allowing adaptation to the practical constraints related to the realization of the installation (safety, external temperature conditions, length of networks...).

[0047] It should also be noted, from a structural point of view, that the hot water distribution circuit and the cold water distribution circuit each include at least one recirculation pump, so that the distribution of hot and cold water can take place under optimal conditions. These recirculation pumps can operate at fixed or variable speed in order to add a level of energy optimization to the system by adapting the flow rate in the primary hydraulic circuits to the flow rates consumed by the air handling unit(s) located downstream.

[0048] Other objects and advantages of the present invention will become apparent from the following description, which relates to an embodiment given by way of example only. Understanding this description will be particularly facilitated by reference to the accompanying figures, in which:

[0049] [Fig-1] shows a general diagram of the installation for a site composed of a plurality of climatic chambers;

[0050] [Fig.2] represents a schematic diagram of the multifunctional heat pump of the cold and heat production unit;

[0051] [Fig.3] schematically shows the configuration of a processing plant of air; and

[0052] [Fig.4] illustrates the operating modes of the power plants with reference to a central diagram representing the main climate parameters being managed, air temperature and humidity.

[0053] Fig. 1 shows the various elements constituting the air treatment system of the invention, namely mainly the heating and cooling unit 1 based on a heat pump and connected to climate chambers 2 each comprising an air handling unit 3. These are in practice connected to the heating and cooling unit 1 via a hot water distribution circuit 4 and a cold water distribution circuit 5 respectively connected to the hot side and the cold side of the heating and cooling unit 1. Inside the climate chambers 2 for growing plants, the control devices or elements enabling regulation by optimizing the operating point are mainly a cooling coil, a heating coil, a fan and a humidifier (their relative arrangement will be seen in more detail later).A three-way solenoid valve 6 and a recirculation pump 7 in the cold water distribution circuit 5, and a two-way solenoid valve 8 in the hot water distribution circuit 4, upstream of the air handling unit 3, control, in particular, the incoming flow rate of the cold and hot circuits. These components are controlled. (flow rate, flow speed...) by a control unit 9 (present in each climate chamber 2), for example a programmable logic controller, based on information from temperature, humidity, CO2 etc. sensors 10 placed in each air handling unit 3 and in each climate chamber 2 of culture.

[0054] With reference to [Fig. 2], the design of the heating and cooling unit is based on a thermodynamic heat pump circuit, for example, a water-to-water heat pump, allowing for the combined, independent, and optimized production of heating and cooling and making it easy to regulate the power exchanged with the heating and cooling sides, i.e., with the hot water distribution circuits 4 and cold water distribution circuits 5, as well as with the outside (excess heat or cold discharge). The operating principle, which has been mentioned previously but is repeated with reference to [Fig. 2], is as follows:

[0055] When cooling demand is predominant, the circuit modulates the speed of compressor CP and the expansion to evaporator EV to deliver the required cooling capacity. Depending on whether or not there is heating demand, the circuit modulates the condensation between the outdoor evaporator-condenser EEC (operating in condenser mode) and the condenser CD to dissipate all excess heat. Conversely, when heating demand is predominant, the circuit adjusts the heating capacity and arbitrates the expansion between the cooling side and the outdoor evaporator-condenser EEC (which then operates in evaporator mode) to dissipate all excess cooling. The switch from one mode to the other is gradual, i.e., without interrupting compressor operation or reversing the direction of fluid flow in the circuit.This avoids the need for an additional component in the circuit, namely a reversing valve, which improves system reliability, particularly by reducing the risk of leakage.

[0056] The use of the EEC evaporator-condenser located near the external source (air or groundwater), which is in fact a heat exchanger with two independent refrigeration and heating circuits (liquid / gas) sharing the same cooler (fins and fan), simplifies the design of the refrigeration circuit in combined operation. This allows for the removal of either excess heat or excess cold in a manner controllable by a system control unit, to ensure minimal energy consumption (compressor rotation + fans and pumps).

[0057] Precise control of the exchange on each side is carried out, optimizing operation by adapting the operating regime of the heating and cooling production unit 1 to that of the load consisting of the downstream air handling units 3, and possibly allowing the use of a variable primary flow rate in said unit 1 maintains a constant delta T on the hot and cold sides by adapting the primary flow rate to the water flow rates required in the heat exchangers of the air handling unit(s) (3) supplied by it. This helps to reduce energy consumption by reducing pressure losses in the hydraulic circuits and optimizing thermodynamic efficiency.

[0058] In the system of the invention, the combined heating and cooling unit 1 uses the principle of a heat pump with total heat recovery to ensure very high-efficiency heating and cooling production (COP > 7). At the outlet, the two distribution circuits 4 and 5 (there may be more) are independent, each equipped with at least one inverter-modulated compressor 11, 12, which first ensures temperature stability while eliminating the need for the large buffer volume required by systems using an on / off compressor. Each circuit is also equipped with its own air-cooled condenser and a total heat recovery heat exchanger, and at least one actuator for regulating the power exchanged with each of them.The coupling of the two main circuits (which are reversible) for the distribution of hot water 4 and cold water 5, each consisting of two supply / return pipes to the air handling units 3, is carried out using actuator-type components (for example, the 2- or 3-way valves 8 and 6, and the recirculation pump 7).

[0059] A control algorithm running on at least one computer or on at least one PLC constituting at least one control unit progressively adapts (precisely dosing power) the operation of the compressors, fans, heat exchangers, and pumps in order to minimize energy consumption. The adaptation of the circulation speed in the primary circuit (internal circuit of the heat pump) and secondary circuit (hot water distribution circuits 4 and cold water distribution circuits 5) is continuous, to obtain an optimal delta T on the production side (at the level of distribution circuits 4 and 5) while ensuring a flow rate just sufficient to supply the heat exchangers, thus limiting the electrical consumption of the pumps to the bare minimum.

[0060] An example of an air handling unit is shown in [Fig. 3]. The unit 3 is housed in a casing 30 which has two spaces 31, 32 located on either side of a physical boundary of the climatic enclosure 2 represented by vertical dashed lines in the figure. In practice, this is, for example, a wall of said enclosure, in which the air handling unit 3 is placed so that one part of the casing 30 (containing the first space 31) is located outside the enclosure 3 while the other part (containing the second space 32) is inside. The part comprising the first space 31 has two openings, an air inlet opening 33 and an air outlet opening 34. The part comprising the second space 32 similarly has two openings, an air inlet opening 35 and an Air outlet opening 36. Each space 31, 32 also includes a fixed internal partition 37, 38 separating it into two parallel corridors 44, 45; 46, 47 respectively, opening into the openings 33, 34 and 35, 36 respectively. The housing 30 of the air handling unit also has movable partitioning means in the form of at least partially retractable walls 40, 41, 42, 43. As will be seen in more detail later, one or more of these partitions can be retracted completely or partially, by means of a mechanical actuator, to allow more or less complete passage of airflows from the inside or outside of the climate chamber, while controlling their trajectory.

[0061] The corridor 44 downstream of the air inlet 33 of the first space 31 connected to the outside air includes a fan 51 and a heat exchanger 52. The corridor 46 downstream of the air inlet 35 of the second space 32 connected to the inside air (the air present in the climatic chamber 3) includes a fan 53 and a heat exchanger 54. The heat exchanger 54 is connected to the heat exchanger 52 of the first space by a pipe 55 carrying a heat transfer fluid. Heat / cooling is extracted from the outside air by the heat exchanger 52 and transferred to the inside air (or vice versa) by means of the heat transfer fluid, thus enabling heat transfer without air exchange. Corridor 47 is equipped, from the inside of the second space 32 towards the air outlet opening 36, with a cold coil 56, followed by a hot coil 57 and a humidifier 58.These cold 56 and hot 57 batteries are respectively cooled by the cold water distribution circuit 5 and heated by the hot water distribution circuit 4, for example by means of coils of tubing carrying the cold or hot water.

[0062] In summary, in the air handling units 3 of the invention, two independent and connectable air loops are created, opening onto the inside and outside of the climate enclosure 2. Energy recovery from the outside and its transmission are carried out by the two additional exchangers 52, 54 (of the type designated by the Anglo-Saxon term run-around coil) coupled between the inside and outside by means of a heat transfer fluid circulating in a tube 55 installed between the two exchangers.In the internal air loop of the culture chamber 2, which is therefore located in the second internal space 32, the additional heat exchanger 54 is placed upstream of the cooling coil 56. This allows the air to be pre-cooled using the heat exchanger 52 located on the external loop of the first space 31, with significantly greater efficiency (a much wider annual operating range) because it requires a much smaller internal / external temperature difference (< 10K). Furthermore, if required for operation (see below), this allows for decoupling between the two internal and external loops to prevent any air exchange.

[0063] As will be seen in more detail later, there may be an opening between the two loops in certain operating conditions, typically when the energy savings for renewing the indoor air exceed the costs incurred by the loss of humidity and CO2 to the outside. The maximum rate of fresh air injection can be adjusted (from 0 to 100%) to accommodate different operational and thermal constraints. In short, the two air loops – indoor and outdoor – can operate independently, or coupled via the additional heat exchanger to maximize energy recovery without air exchange, or by allowing partial air exchange.

[0064] The air passage circuits can be rearranged using the movable partitioning means 40, 41, 42, 42, according to requirements, by means of a mechanical actuator (not shown) controlled by the control unit of the air handling unit 3. Four operating configurations are shown in [Fig. 4]. They are explained below, starting with the one shown in the upper right, and then successively in a clockwise direction.

[0065] The configuration in the upper right illustrates closed-loop control: it involves the use of three of the four movable walls 40, 41, and 43. The airflow can therefore pass between corridors 46 and 47 and form an internal loop in the second interior space 32, where the air circulates in a closed loop. The presence of wall 43, however, prevents any closed-loop circulation of the exterior air in the first space 31. The cooling coils 56 and 57 provide all the heat dissipation for the return air. This is shown in the central diagram, where we are in the "closed-loop" zone, without any fresh air supply. This configuration can be used when the outside temperature Text is higher than the inside temperature Tint, while the control system requires cooling of the return air and vice versa, or when humidification is required.

[0066] The configuration in the lower right illustrates another closed-loop regulation, which involves the use of two of the four movable walls 40, 4L. The airflow can therefore pass between corridors 46 and 47, and form an internal loop in the second space 32, where the air operates in a closed internal loop. It can also pass between corridors 44 and 45, and form a loop in the first external space 31: the air then also circulates in a closed external loop. The cooling coil 56 and the heating coil 57 ensure all the heat dissipation on the return air.This is a configuration that can be used when the outside temperature Text is lower than the inside temperature Tint, and when the outside humidity He is higher than the inside humidity Hi, in order to achieve pre-cooling (noted "freecooling" in the corresponding central diagram area) by recovering cooling from the outside air via the exchangers 52 and 54 connected by the tubing 55, and . without air exchange between spaces 31 and 32. This configuration helps to limit energy consumption by keeping water vapor and CO2 inside culture chamber 2.

[0067] In the configuration at the bottom left, three of the four movable walls 40, 41, 42 are partially retracted, allowing a partial passage of air and partial operation with fresh air (from outside), as shown in the central diagram. The movable partition 43 is present, preventing air circulation between corridor 44 and corridor 45. Airflow can therefore pass from the outside to the inside, via corridors 44 and 47, and also from the inside to the outside via corridors 46 and 45. In other words, the circuits are such that they connect, on the one hand, the external inlet opening 33 and the internal outlet opening 36, and on the other hand, the internal inlet opening 35 and the external outlet opening 34. Air can also circulate between corridors 46 and 47, and thus form a loop in the second internal space 32.This operating mode is used, for example, when the outside humidity (He) is lower than the inside humidity (Hi) and the outside temperature (Text) is less than or equal to the inside temperature (Tint), in the case where the system is controlling a cooling demand. It is also used when the outside humidity (He) is lower than the inside humidity (Hi) and the outside temperature (Text) is greater than or equal to the inside temperature (Tint), in the case where the system is controlling a heating demand. A portion of the air extracted from the outside atmosphere is reinjected before the cooling coil (56) to directly benefit from the lower temperature and humidity of the outside air and thus limit energy consumption.

[0068] In the configuration at the top left, the two movable walls 42, 43 are present, allowing air to pass through and fresh air operation from the outside to the inside, via the corridors 44 and 47, and also from the inside to the outside via the corridors 46 and 45. No air passage is possible between the corridor 44 and the corridor 45 of the first external space 31, and there is also no air circulation between the corridor 46 and the corridor 47 of the second internal space 32. This is an operation which is in principle activated manually, in total fresh air ventilation mode (see central diagram), or which can be programmed at different times of the culture cycle in order to achieve regular air renewal allowing, for example, the removal of undesirable compounds present in the atmosphere of the enclosure (ethylene...).The two exchangers 52, 54 function as heat recovery units used to pre-condition the air in certain cases to limit the thermal load on the cold 56 and hot 57 batteries.

[0069] The energy savings enabled by the system of the present invention are significant:

[0070] - thus, with a strategy prioritizing maximum energy savings, the The proposed system reduces electricity consumption by 71% compared to an existing installation, at the cost of water loss representing 86% of the evapotranspiration generated by the crop;

[0071] - with a strategy balancing energy savings and air recycling, the Electricity consumption is down by 51%, with only 14% water loss.

[0072] The energy efficiency gain is therefore significant and, even in the case where the water loss is significant, the economic balance is favorable: the gains made in terms of operating cost more than compensate for the possible additional cost related to the additional equipment that may be required.

[0073] The example configuration shown in the figure should not be considered exhaustive of the invention, which includes variations, for example in the shape of the air handling units, in the arrangement or number of components, or in the configuration of the hydraulic circuits. Furthermore, the delimitation of the two spaces, respectively interior and exterior, can be achieved in another way, in the case of a cross-flow plate heat exchanger in which the outside air and extracted or recycled air flows intersect.

Claims

Demands

1. An air handling system for the adjustable regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment, characterized in that it comprises: - a combined heating and cooling production unit (1) comprising a heat pump, a hot water distribution circuit (4) and a cold water distribution circuit (5); - a plurality of air handling units (3), each enclosure (2) being equipped with at least one air handling unit (3); - each air handling unit (3) comprising: an air handling unit (30) having two openings (35, 36) opening into the interior of the enclosure (2) and two openings (33, 34) opening outwards from the exterior of the enclosure (2), air conditioning components, fixed internal partitions (37, 38) and movable partitioning means cooperating with the fixed partitions (37, 38) and walls of the unit (30) to delimit at least one air conditioning circuit in the unit (30), each circuit having an air inlet opening, at least one fan (51, 53) directing the airflow and an air outlet opening, said air inlet and air outlet openings of the circuit being two of the four openings (33, 34, 35, 36) opening into the interior and outwards of the enclosure (2); at least one heat exchanger (52) allowing the recovery of thermal energy from the outside air, capable of using the outside air as a source of thermodynamic energy in order to carry out the heating, cooling or dehumidification of the inside air without exchange of air between the inside and outside of the enclosure (30); hydraulic components connecting the hot water (4) and cold water (5) distribution circuits of the unit of cold and heat production (1) and the components of the air handling unit (30); • at least one control unit of said hydraulic linking components connected to at least one sensor of at least one parameter of the air in the enclosure (2); • means of controlling the flow and temperature of the air in the air handling unit (30) and means of controlling the flow and temperature of the water in the air conditioning components of said unit (30).

2. Air handling system for the adjustable regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to the preceding claim, characterized in that the movable partitioning means comprise on the one hand at least one wall (40; 41) at least partially retractable capable of separating a first space (31) comprising the two openings (33, 34) opening towards the outside of the enclosure (2) from a second space (32) comprising the two openings (35, 36) opening towards the inside of the enclosure (2), and on the other hand at least one wall (42; 43) at least partially retractable capable of separating the openings (35, 35; 33, 34) of the same space (32; 31).

3. Air handling system for the modulable regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to the preceding claim, characterized in that the air inlet opening (33) of the first space (31) is coaxial with the air outlet opening (36) of the second space (32), and the air outlet opening (34) of the first space (31) is coaxial with the air inlet opening (35) of the second space (32).

4. An air handling system for the adjustable regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to any one of claims 2 and 3, characterized in that the first space (31) comprises a fixed internal partition (37) dividing it into two parallel corridors (44, 45) opening into the openings (33, 34) of said first space (31) and connected to each other, in the vicinity of a partition wall (40, 41) that is at least partially retractable. second space (32), by a passage that can be closed by means of movable partitioning (43), a first corridor (44) opening into the air inlet opening (33) comprising a fan (51) and an exchanger (52).

5. An air handling system for the adjustable regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to the preceding claim, characterized in that the second space (32) comprises a fixed internal partition (38) dividing it into two parallel corridors (46, 47) opening onto the openings of said second space (32) and connected to each other, in the vicinity of a partition wall (40, 41) at least partially retractable separating it from the first space (31), by a passage closable by means of movable partitioning (42), a first corridor (46) opening into the air inlet opening (35) comprising a fan (53) and a heat exchanger (54) positioned downstream of the fan (53), said heat exchanger (54) being connected by a pipe (55) carrying a heat transfer fluid to the heat exchanger (52) of the first space (31), the second corridor (47) comprising a cold battery (56),a heating coil (57) and a humidifier (58) proximal to the air outlet opening (36).

6. Air handling system for the modulable regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to the preceding claim, characterized in that the cold coil (56) comprises at least one air / water cooling and dehumidification exchanger connected to the cold water distribution circuit (5) and the hot coil (57) comprises at least one air / water heating exchanger connected to the hot water distribution circuit (4).

7. An air handling system for the adjustable regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to any one of the preceding claims, characterized in that the hydraulic components connecting the hot water (4) and cold water (5) distribution circuits of the heating and cooling unit (1) and the components of the air handling unit housing (30) of each air handling unit comprise: - in a connection conduit to the cold water distribution circuit (5), a three-way valve (6) and a recirculation pump (7) controlled by a control unit (9) linked to the air handling unit (3); and - in a connection conduit to the hot water distribution circuit (4), a two-way valve (8) controlled by said control unit (9).

8. Air handling system for the modulating regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to the preceding claim, characterized in that the three-way valve (6), the recirculation pump (7) and the two-way valve (8) are controlled proportionally.

9. Air handling system for the modulating regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to any one of the preceding claims, characterized in that the hot water distribution circuit (4) of the cold and heat production unit (1) comprises at least one water line connected by an exchanger to the condenser (CD) of the heat pump, and the cold water distribution circuit (5) comprises at least one water line connected by an exchanger to the evaporator (EV) of the heat pump.

10. Air handling system for the modulating regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to any one of the preceding claims, characterized in that the heat pump of the cooling and heating production unit (1) comprises at least one external evaporative condenser (EEC) connected to an external heat source, consisting of a heat exchanger having two independent cooling and heating circuits respectively sharing the same cooler.

11. Air handling system for the modulating regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to the preceding claim, characterized in that the heat pump of the heating and cooling unit (1) includes means for controlling the operation of the evaporator-condenser (EEC) respectively in evaporator or condenser, said control means comprising means for processing the demand for hot or cold water by the air handling units (3) of the enclosures (2).

12. Air handling system for the modulable regulation of temperature and humidity in a plurality of plant production enclosures (2) in a controlled environment according to any one of the preceding claims, characterized in that the hot water distribution circuit (4) and the cold water distribution circuit (5) each comprise at least one recirculation pump (11, 12).

Images