Heat recovery unit and kitchen ventilation system

Abstract

TITLE: Heat recovery unit and kitchen ventilation system Heat recovery unit (3) comprising: a heat exchanger (34); a supply inlet (20) and a supply outlet (21) for a supply airflow (F2); an inlet compartment (32), an exhaust inlet (22) and an exhaust outlet (23), for a stale airflow (F1); and a sprayer (37) for cleaning the heat exchanger (34).According to the invention, the heat recovery unit (3) comprises a bypass duct (35) and a shut-off system (36), which, in a recovery configuration, connects the inlet compartment (32) to the heat exchanger (34) so ​​that the exhaust airflow (F1) circulates through the heat exchanger (34), and which, in a bypass configuration, fluidly connects the exhaust inlet (22) to the bypass duct (35), so that the exhaust airflow (F1) circulates through the bypass duct (35) without circulating through the heat exchanger (34). Figure 1 for the abstract.

Description

Title of the invention: Heat recovery and kitchen ventilation installation

[0001] The present invention relates to a heat recovery unit and a kitchen ventilation installation comprising such a heat recovery unit.

[0002] The invention relates in particular to the technical field of dual-flow ventilation installations, which are capable of extracting a flow of stale air, containing in particular kitchen fumes, from the interior of a building, of introducing into the building a flow of blown air coming from outside the building, and of ensuring a heat exchange between the flow of stale air and the flow of blown air, without bringing said flows into contact. The invention is not limited to specifically equipping a kitchen, but can equip other premises which produce, not kitchen fumes, but other types of flow of stale air, in particular those laden with grease.

[0003] FR 2 953 002 B1 describes a ventilation installation, with means for extracting stale air laden with grease from a first room such as a kitchen area, means for blowing air into a second room and a heat recovery unit, provided with a double-flow heat exchanger through which the flow of stale air and the second flow of air to be blown pass, the flows being isolated from each other.

[0004] The heat recovery unit comprises an internal conduit for diverting the blown air flow. The heat exchanger and the internal conduit are each provided with closure means allowing the passage of the blown air flow through the internal conduit and / or through the heat exchanger, which makes it possible to adjust the heat exchange between the two flows. It is provided that, during spraying, the second air flow is completely diverted through the internal conduit, if the temperature of the blown air flow is lower than the temperature of the first air flow, so that cleaning is improved, in that the heat input by the stale air can have a catalytic effect on cleaning.

[0005] The heat recuperator also comprises a cleaning sprayer, placed in the stale air flow, upstream of the heat exchanger, and means for detecting the circulation of the stale air flow in the exchanger. The spraying is triggered only if the stale air flow circulates in the exchanger. Thanks to this spraying, the installation requires little maintenance. Even if this recuperator generally gives satisfaction, its use may involve the spraying of a substantial quantity of cleaning product.

[0006] The invention aims to resolve the drawbacks of the prior art such as those mentioned above, by proposing a new heat recovery unit which, while giving the possibility of activating or not the heat recovery, makes it possible to reduce the amount of cleaning product required.

[0007] The invention relates to a heat recovery unit for a kitchen ventilation installation, the heat recovery unit comprising: a heat exchanger; an insufflation inlet, which opens outside the heat recovery unit; an insufflation outlet, which opens outside the heat recovery unit and which is fluidically connected to the insufflation inlet via the heat exchanger, so that a flow of insufflated air circulates from the insufflation inlet to the insufflation outlet via the heat exchanger; an inlet compartment, which opens onto the heat exchanger; an extraction inlet, which opens outside the heat recovery unit and into the inlet compartment to be fluidically connected to the heat exchanger via the inlet compartment when the heat recovery unit is in a recovery configuration;an extraction outlet, which opens outside the heat recovery unit and which is fluidically connected to the inlet compartment via the heat exchanger when the heat recovery unit is in the recovery configuration, so that a flow of stale air, in particular loaded with grease and / or water vapor, circulating from the extraction inlet to the extraction outlet, passes through the inlet compartment then the heat exchanger to exchange heat with the flow of air blown into the heat exchanger; and a sprayer, arranged in the inlet compartment, capable of spraying a cleaning product to clean the heat exchanger of fouling caused by the flow of stale air. ;

[0008] According to the invention, the heat recovery unit further comprises a bypass duct, arranged against the heat exchanger, the extraction inlet being fluidically connected to the extraction outlet, successively via the inlet compartment and the bypass duct, when the heat recovery unit is in a bypass configuration.

[0009] According to the invention, the heat recovery unit further comprises a closure system, which: in the recovery configuration, fluidly connects the inlet compartment to the heat exchanger, so that the stale air flow circulates in the heat exchanger, and in the bypass configuration, fluidly separates the inlet compartment from the heat exchanger and fluidly connects the extraction inlet to the bypass duct, so that the stale air flow circulates in the bypass duct without circulating in the heat exchanger.

[0010] An idea underlying the invention is to provide that, by choosing to put the heat recovery unit in recovery configuration or in bypass configuration, one chooses to activate or interrupt the heat recovery by heat exchange between the stale air flow and the air flow blown into the heat exchanger. When the heat recovery unit is in bypass configuration, the stale air flow does not pass through the heat exchanger. In confi In the bypass configuration, the heat exchange between the two flows is limited or even absent. The heat recovery unit can be put into bypass configuration, for example, when the temperature of the stale air flow is too close to the temperature of the supply air flow, making heat exchange unnecessary, or for example when the temperature of the supply air flow is low enough to cause a risk of freezing, on the stale air flow side, within the heat exchanger.

[0011] It follows that the collector is brought to be put in the configuration of bypass for a substantial part of its use. Thanks to the invention, in the bypass configuration, the stale air flow does not foul, or fouls less, the heat exchanger, so that less cleaning of the heat exchanger is necessary. Fouling of the bypass duct is less critical than that of the heat exchanger, since the bypass duct can easily be designed to be easier to clean and can have a sufficiently large passage section to avoid any risk of clogging. Thus, a significantly smaller quantity of product for degreasing is required, without sacrificing reduced maintenance.

[0012] Preferably, the heat exchanger comprises a primary inlet, fluidly connecting the inlet compartment with the heat exchanger when the heat recuperator is in the recovery configuration; and the bypass conduit comprises a bypass inlet, fluidly connecting the inlet compartment with the bypass conduit when the heat recuperator is in the bypass configuration.

[0013] Preferably, the primary inlet and the bypass inlet are adjacent and arranged in the same plane.

[0014] Preferably, the shutter system comprises a first shutter, for selectively closing the primary inlet, and a second shutter, for selectively closing the bypass inlet, the first shutter and the second shutter being mechanically linked, such that, when the first shutter is in an open position, the second shutter is in a closed position and such that, when the first shutter is in a closed position, the second shutter is in an open position.

[0015] Preferably, the first shutter consists of a first set of shutters and the second shutter consists of a second set of shutters.

[0016] Preferably, the heat recovery unit further comprises a return spring, exerting a return force on the closure system, tending to actuate the closure system to put the heat recovery unit in the recovery configuration, when the heat recovery unit is in the bypass configuration.

[0017] Preferably, the heat recovery unit further comprises a motor, for operate the shutter system and thus selectively put the heat recovery unit in recovery configuration and in bypass configuration.

[0018] Preferably, the heat recovery unit further comprises a control unit, which is configured to put the heat recovery unit in a maximum recovery configuration, where the closure system fluidly separates the extraction inlet from the bypass duct so that the stale air flow does not circulate in the bypass duct, when the temperature measured by a temperature sensor of the stale air flow exceeds a predetermined threshold value and / or when a fire is detected.

[0019] Preferably, in the recovery configuration, the closure system is configured to fluidly connect the inlet compartment to the bypass duct so that, while a first portion of the stale air flow circulates in the heat exchanger, a second portion of the stale air flow circulates in the bypass duct, the closure system being configured to allow adjustment of a ratio between the first portion and the second portion of the stale air flow. Preferably, the control unit is configured to control the closure system to adjust said ratio, based on a measurement made by a sensor.

[0020] Preferably, the heat recovery unit is a static heat recovery unit.

[0021] The invention also relates to a kitchen ventilation installation, comprising: the heat recovery unit as defined above; an extraction motor-fan unit, arranged outside the heat recovery unit and being fluidically connected to the extraction outlet, for circulating the stale air flow; and an insufflation motor-fan unit, arranged outside the heat recovery unit and being fluidically connected to the insufflation outlet, for circulating the insufflated air flow.

[0022] Other characteristics and advantages of the invention appear in the following description of embodiments of the invention, given by way of example, and with reference to the following drawings.

[0023] [Fig-1] [Fig.l] is a schematic view of a kitchen ventilation installation according to one embodiment of the invention, including a heat recovery unit.

[0024] [Fig.2] [Fig.2] is a perspective view of the heat recovery unit of [Fig.l].

[0025] [Fig.3] [Fig.3] is another perspective view of the heat recovery unit of the previous figures.

[0026] [Fig.4] [Fig.4] is another perspective view of the heat recovery unit of the previous figures, part of which is cut off.

[0027] [Fig.l] shows a kitchen ventilation installation 1, equipping a building comprising a kitchen 2, i.e. a room for cooking. The installation aims to extract a flow of stale air Fl, in particular a flow of air loaded with grease and / or kitchen fumes and / or water vapor from inside kitchen 2 to the outside of the building, and to blow a flow of blown air F2 from outside the building to the inside of kitchen 2, or from another room of the building.

[0028] Alternatively, the installation 1 can be implemented for uses other than for a kitchen, since a flow of stale air loaded with grease and / or water vapor must be extracted, this flow of air being able to come for example from an industrial installation rather than from a kitchen.

[0029] As shown in [Fig.l], the installation 1 comprises a heat recovery unit 3, an extraction motor-fan unit 4, an insufflation motor-fan unit 5, a hood 6 and ducts 7, 8 and 9 for the circulation of the flows F1 and F2.

[0030] The hood 6 is arranged in the kitchen 2, preferably above a cooking appliance 10 generating the stale air flow F2. The hood 6 comprises an inlet opening 11 for the flow F1 produced by the appliance 10. The hood 6 also comprises an opening 12 for introducing the blown air flow F2 into the kitchen 2. Alternatively, the opening 12 may be provided elsewhere in the kitchen 2, or in another room of the building.

[0031] Alternatively, instead of the hood 6, a kitchen ceiling, sometimes called a “filtering ceiling”, or “suction ceiling”, may be provided, providing the same functions and having one or more intake openings for admitting the flow F1 like the opening 11, and one or more openings for introducing the flow F2, like the opening 12.

[0032] The heat recovery unit 3 comprises an insufflation inlet 20, an insufflation outlet 21, an extraction inlet 22 and an extraction outlet 23.

[0033] The opening 11 is fluidically connected to the extraction inlet 22 by the duct 7, so that the flow F1 circulates from the opening 11 to the extraction inlet 22. The flow F1 then circulates within the recuperator 3 to the extraction outlet 23. The extraction outlet 23 is fluidically connected to the motor-fan unit 4, so that the flow F1 circulates from the outlet 23 to the unit 4. The unit 4 then circulates the flow F1 to the outside of the building, possibly via another duct opening outside the building. The unit 4 ensures the circulation of the flow F1 and is outside the heat recuperator 3, being preferably connected downstream of the outlet 23.

[0034] The flow F2 coming from outside the building is introduced into the recuperator 3 at the insufflation inlet 20, possibly via a duct opening outside the building. The flow F2 then passes through the recuperator 3 and leaves it via the insufflation outlet 21. The duct 9 fluidically connects the outlet 21 to the motor-fan unit 5, then to the opening 12. The flow F2 therefore circulates in the duct 9 from the outlet 21, to pass through the unit 5 and then be blown into the kitchen 2 via the opening 12.

[0035] Block 5 ensures the circulation of flow F2 and is outside the heat recovery unit 3, being preferably connected downstream of outlet 21.

[0036] It is preferably provided that the heat recuperator 3 is a static heat recuperator, that is to say a recuperator 3 which does not itself ensure the circulation of flows F1 and F2, for example by being devoid of motor-driven fans, and, more generally, of means for circulating the flows F1 and F2. It is specifically provided that the blocks 4 and 5, separated from the recuperator 3 and outside the recuperator 3, ensure the circulation of the flows F1 and F2, preferably by themselves, or otherwise possibly with the help of other means, such as motor-driven fans, provided within the hood 6. Each motor-driven fan block for example in the form of an individual box, carrying a motor-driven fan, that is to say a ventilation wheel, for example centrifugal, actuated by a motor, and thus putting the flow concerned into circulation.

[0037] The heat recovery unit 3 comprises an inlet compartment 30, an outlet compartment 31, an inlet compartment 32, an outlet compartment 33, a heat exchanger 34, a bypass duct 35, a sealing system 36 and a sprayer 37. The compartments 30, 31, 32 and 33, the exchanger 34, the duct 35, the sealing system 36 and the sprayer 37 are all contained in the same box belonging to the heat recovery unit 3. The sealing system 36 causes the recovery unit 3 to evolve between a recovery configuration and a bypass configuration.

[0038] The inlet 20 opens into the compartment 30, connecting the compartment 30 directly with the outside of the recuperator 3. The inlet 22 opens into the compartment 32, connecting the compartment 32 directly with the outside of the recuperator 3. The outlet 21 opens into the compartment 31, connecting the compartment 31 directly with the outside of the recuperator 3. The outlet 23 opens into the compartment 33, connecting the compartment 33 directly with the outside of the recuperator 3. Preferably, the inlet 22 and the outlet 21 are arranged at the same end of the recuperator 3. The inlet 20 and the outlet 23 are arranged at the same end of the recuperator 3, opposite that carrying the inlet 22 and the outlet 21. Preferably, the inlet 22 is arranged above the outlet 21. Preferably, the inlet 20 is located above exit 23.

[0039] Preferably, the compartments 31 and 32 are arranged at the same end of the collector 3. The compartments 30 and 33 are arranged at the same end of the collector 3, opposite that of the compartments 31 and 32. Preferably, the compartment 32 is arranged above the compartment 31 and is adjacent thereto. Preferably, the compartment 30 is arranged above the compartment 33 and is adjacent thereto. Preferably, in the lengthwise direction of the collector 3, the compartment 32 is adjacent to compartment 30. Preferably, in the length direction of the collector, compartment 31 is adjacent to compartment 33.

[0040] The heat exchanger 34 is here a counter-current heat exchanger, that is to say a cross-flow heat exchanger. The heat exchanger 34 is preferably a plate exchanger, but could, as a variant, be a tube exchanger. The heat exchanger 34 is designed to promote heat exchange between the flows F1 and F2 passing through it, without bringing the flows F1 and F2 themselves into contact.

[0041] The heat exchanger 34 is arranged between the compartments 30, 31, 32 and 33, being adjacent to each of them. The heat exchanger 34 comprises a primary inlet 42, a primary outlet 43, a secondary inlet 40 and a secondary outlet 4L. When the recuperator 3 is in the recovery configuration, the primary inlet 42 opens into the compartment 32. The primary inlet 42 is fluidically connected to the primary outlet 43 via a primary exchange battery within the exchanger 34. The primary outlet 43 opens into the compartment 33. The secondary inlet 40 opens into the compartment 30, and is fluidically connected to the secondary outlet 41 via a secondary exchange battery within the exchanger 34. The secondary outlet 41 opens into the compartment 31.

[0042] In the recovery configuration, the inlet 22 is fluidically connected to the outlet 23 via the heat exchanger 34. In more detail, the inlet 22 is fluidically connected to the inlet 42 via the compartment 32, the inlet 42 being fluidically connected to the outlet 43 via the primary circuit of the exchanger 34, and the outlet 43 is fluidically connected to the outlet 23 via the compartment 33. Therefore, in the recovery configuration, the flow F1, or at least a portion of the flow F1, circulates successively through the inlet 22, the compartment 32, the inlet 42, the primary circuit of the exchanger 34, the outlet 43, the compartment 33 and the outlet 23.

[0043] In both the recovery configuration and the bypass configuration, the inlet 20 is fluidically connected to the outlet 21 via the heat exchanger 34. In more detail, the inlet 20 is fluidically connected to the inlet 40 via the compartment 30, the inlet 40 being fluidically connected to the outlet 41 via the secondary circuit of the exchanger 34, and the outlet 41 is fluidically connected to the outlet 21 via the compartment 31. Therefore, in both the recovery configuration and the bypass configuration, the flow F2 circulates successively through the inlet 20, the compartment 30, the inlet 40, the secondary circuit of the exchanger 34, the outlet 41, the compartment 31 and the outlet 21.

[0044] The bypass conduit 35 comprises a bypass inlet 52 and a bypass outlet 53. In the bypass configuration, the inlet 52 opens into the compartment 32 and the outlet 53 opens into the compartment 33. In the bypass configuration, and possibly in the recovery configuration, the inlet 22 is fluidically connected to the outlet 23 via the bypass duct 35. In more detail, the inlet 22 is fluidically connected to the inlet 52 via the compartment 32, the inlet 52 being fluidically connected to the outlet 53 via the bypass duct 35, and the outlet 53 is fluidically connected to the outlet 23 via the compartment 33. Therefore, in the bypass configuration, the flow F2 circulates successively through the inlet 22, the compartment 32, the inlet 52, the bypass duct 35, the outlet 53, the compartment 33 and the outlet 23. Within the recuperator 3, the bypass duct 35 is separated from the compartments 30 and 31.

[0045] The bypass duct 35 is arranged between the compartments 30, 31, 32 and 33, being adjacent to each of them. As clearly visible in Figures 2 and 4, the exchanger 34 and the bypass duct 35 are arranged against each other within the recuperator 3, in particular, within the box of the recuperator 3. By being side by side, it is preferably understood that the exchanger 34 and the duct 35 are arranged side by side in the direction of the width of the recuperator 3, in other words, in a transverse arrangement with respect to the flows F1 and F2.

[0046] The bypass duct 35 and the heat exchanger 34 advantageously form a block which is arranged approximately in the center of the recuperator 3.

[0047] Preferably, for the primary circuit of the exchanger 34, the inlet 42 and the outlet 43 are arranged at opposite ends of the exchanger 34. The inlet 42 and the outlet 43 are oriented in parallel planes and are turned in opposite directions from each other. The inlet 42 and the outlet 43 are advantageously arranged obliquely relative to the wall carrying the inlet 22 and to that carrying the outlet 23.

[0048] Preferably, for the secondary circuit of the exchanger 34, the inlet 40 and the outlet 41 are arranged at opposite ends of the exchanger 34. The inlet 40 and the outlet 41 are oriented in parallel planes and are turned in opposite directions from each other. The inlet 40 and the outlet 41 are advantageously arranged obliquely relative to the wall carrying the inlet 20 and to that carrying the outlet 21. The inlet 40 and the outlet 41 are arranged in planes which are perpendicular to those of the inlet 42 and the outlet 43.

[0049] Preferably, for the bypass duct 35, the inlet 52 is adjacent and in the same plane as the inlet 42, while the outlet 53 is adjacent and in the same plane as the outlet 43. Thus, like the inlet 42 and the outlet 43 of the exchanger 34, the inlet 52 and the outlet 53 are advantageously arranged obliquely.

[0050] In the bypass configuration, the closure system 36 fluidly separates the compartment 32 from the heat exchanger 34, at the inlet 42, while fluidly connecting the compartment 32 to the bypass conduit 35, at the inlet 52. Conversely, in the recovery configuration, the closure system 36 fluidly connects the compartment 32 with the heat exchanger 34. heat 34, at the inlet 42. In the recovery configuration, it can be provided that the closure system 36 fluidly separates the compartment 32 from the bypass duct 35, at the inlet 52, so that the stale air flow F1 does not circulate in the bypass duct 35 and circulates entirely in the exchanger 34. Additionally or alternatively, in the recovery configuration, it can be provided that the closure system 36 connects not only the compartment 32 with the heat exchanger 34, but also with the bypass duct 35, so that a first part of the flow F1 circulates in the heat exchanger 34 and a second part of the flow F1 circulates in the bypass duct 35.Then, it can advantageously be provided that the closure system 36 makes it possible to adjust the ratio between the first part and the second part of the flow Fl, that is to say what proportion of the flow rate Fl passes through the exchanger 34 and what complementary proportion of the flow rate Fl passes through the conduit 35.

[0051] As visible in [Fig.2], to be able to select whether the compartment 32 is connected or separated from the exchanger 34 and / or the bypass duct 35, the closure system 36 preferably comprises a first closure 61, for selectively closing the primary inlet 42 of the exchanger 34, and a second closure 62, for selectively closing the bypass inlet 52. The closures 61 and 62 are advantageously arranged in the compartment 32. Here, in the manner of a register, each of the closures 61 and 62 is formed by a set of pivoting flaps, arranged against the inlets 42 and 52 to cover them. Each flap moves between an open position and a closed position, to release or close a corresponding portion of the opening that it covers.

[0052] When the flaps of the shutter 61 are all in the closed position, the inlet 42 is closed, which separates the exchanger 34 from the compartment 32. When the flaps of the shutter 61 are in the open position, the inlet 42 is released, which fluidically connects the compartment 32 to the exchanger 34, thus allowing the flow F1 to flow from one to the other. Preferably, the shutter 61 can adopt one or more intermediate positions between the open position and the closed position, as shown in [Fig. 2], in which each flap is in a partially open position, thus allowing the flow F1 to pass through, at a reduced flow rate.

[0053] When the shutters of the shutter 62 are all in the closed position, the inlet 52 is closed, which separates the bypass duct 35 from the compartment 32. When the shutters of the shutter 62 are in the open position, the inlet 52 is released, which fluidically connects the compartment 32 to the duct 35, thus allowing the flow F1 to flow from one to the other. Preferably, the shutter 62 can adopt one or more intermediate positions between the open position and the closed position, as shown in [Fig. 2], in which each shutter is in a par- partially open, thus allowing the passage of the flow Fl, at reduced flow rate.

[0054] In detail, each shutter is preferably mounted pivoting between the open position and the closed position around an individual horizontal axis, here directed in the direction of the width of the recuperator 3. The shutter 61 comprises several shutters so as to cover the entire surface of the inlet 42, here five shutters. Similarly, the shutter 62 comprises several shutters so as to cover the entire surface of the inlet 52, here also five shutters. The shutters of the shutter 61 are coordinated by a mechanical system, so as to all adopt the same position at the same time, as shown in [Fig. 2]. Similarly, the shutters of the shutter 62 are coordinated by a mechanical system, so as to all adopt the same position at the same time, as shown in [Fig. 2]. To this end, it is provided for example that the shutters are linked by mechanical transmission at one of their ends, for example a linkage.

[0055] Furthermore, it is advantageously provided that the two shutters 61 and 62 are mechanically linked, so that, when the shutter 61 is in an open position, the shutter 62 is in a closed position and vice versa. Optionally in this case, the degree of opening of the shutter 61 is inverse to the degree of opening of the shutter 62. For example, when the shutter 61 is partially open, the shutter 62 is partially closed, and vice versa.

[0056] In order to ensure that the two shutters 61 and 62 are thus mechanically linked, it can be provided that, as shown in [Fig. 2], each flap of the shutter 61 is integral in rotation with one of the flaps of the shutter 62, so that, in pairs, the flaps of the shutters 61 and 62 rotate at the same time around their axis. For example, each flap of the shutter 61 can be mounted on the same shaft as one of the flaps of the shutter 62, these two flaps being oriented at 90 degrees relative to each other. Alternatively, each flap of the shutter 61 can be linked to one of the flaps of the shutter 62 by a mechanical transmission, comprising for example a linkage and / or gears.

[0057] In the recovery configuration, while the flow F2 and the flow F1, or a portion of the flow F1, pass through the exchanger 34, the flows F1 and F2 exchange heat. This recovery configuration allows in particular, when the flow F1 is hotter than the flow F2 and there is a heating requirement for the building, in particular the kitchen 2, that the flow F1 passing through the exchanger 34 gives up a portion of its heat to the flow F2 to heat it. Thus, while the building, in particular the kitchen 2, is ventilated by extraction of the flow F1 and insufflation of the flow F2, a portion of the heat of the flow F1 is recovered and reinjected into the building via the flow F2, which makes it possible to save heating energy for the building.

[0058] In the bypass configuration, while the flow F1 circulates through the bypass conduit 35 and the flow F2 circulates through the secondary circuit of exchanger 34, there is no, or very little, heat exchange between flows Fl and F2.

[0059] In the recovery configuration, it can be provided that the closure system 36 requires the flow F1 to pass through the exchanger 34 without passing through the bypass duct 35 and / or that the closure system 36 authorizes the flow F1 to circulate, for the first part of the flow F1, via the exchanger 34, and simultaneously, for the second part of the flow F1, via the bypass duct 35. In the present example, this is possible in the configuration of [Fig. 2] where the shutters 62 and 61 are both in a partially open position.

[0060] It may also be provided that the closure system 36 makes it possible to adjust the proportion of the flow F1 passing through the exchanger 34 relative to that passing through the conduit 35, in order to adjust the intensity of the heat exchange, between a maximum recovery configuration, where a maximum or total proportion of the flow F1 passes through the exchanger 34, and a partial recovery configuration, where the first part of the flow F1 passes through the exchanger 34 while the other part of the flow F1 passes through the bypass conduit 35. This is possible by adjusting the degree of opening of the shutters 61 and 62, which limit the proportions of the flow F1 passing through the exchanger 34 and the conduit 35. For example, the flaps of the shutters 61 and 62 adopt desired intermediate positions between their open and closed positions, in order to obtain the desired adjustment.

[0061] The sprayer 37, shown in [Fig.l], is arranged in the inlet compartment 32. The sprayer 37 comprises for example a ramp, extending in the direction of the width of the recuperator 3, connecting for example the opposite vertical walls of the compartment 32. The sprayer 37 is provided with one or more nozzles, where appropriate, distributed along the ramp, capable of projecting or spraying a cleaning product towards the inlet 42 of the exchanger 34 and possibly towards the inlet 52 of the bypass duct 35. The nozzle(s) can be configured so that the projection of product covers an entire surface of the exchanger 34 and possibly of the duct 35. The cleaning product thus projected onto the exchanger 34 aims to clean fouling of the exchanger 34 caused by the flow FL. Optionally, the cleaning product projected onto the bypass duct 35 aims to clean a blockage in conduit 35.The spraying is advantageously carried out while the air flow Fl is circulating, so that the cleaning product can be transported by the air flow Fl to the parts to be cleaned of the exchanger 34 and / or the bypass duct 35.

[0062] To supply the sprayer 37 with cleaning product, the collector 3 may optionally comprise an on-board reserve of cleaning product 75, provided for example in a maintenance compartment 76 of the collector 3, as shown in [Fig. 4]. The maintenance compartment is for example adjacent to the compartments 30 and 33, and is accessible by one person from outside the collector 3.

[0063] Maintenance of the collector 3 is facilitated thanks to the sprayer 37, which can be activated automatically, at regular intervals and / or depending on particular conditions, such as when the flow F1 is circulating and / or when the collector is in the recovery configuration.

[0064] During a substantial part of the use of the recuperator 3 where the flow F1 passes through the bypass duct 35, the flow F1 does not produce fouling within the exchanger 34, which makes it possible to facilitate maintenance and to reduce the consumption of cleaning product, since the cleaning of the duct 35 is less often necessary and can possibly be carried out manually, the duct 35 being less tortuous than the exchanger 34.

[0065] According to a variant, the sprayer 37 is used only to clean the exchanger 34, being activated only in the recovery configuration, in order to save cleaning product, while the bypass conduit 35 presents little risk of obstruction by the greases of the flow F1.

[0066] The recuperator 3 advantageously comprises a motor 64, preferably an electric motor such as a servomotor, for actuating the shutter system 36 and thus automatically moving the shutters 61 and 62 between the open position and the closed position. Preferably, the motor 64 is a servomotor. Thus, the motor 64 moves the recuperator 3 between the recovery configuration and the bypass configuration, and, if provided, adjusts the degree of closure of the closure system in the recovery configuration, to adjust the proportion of flow F1 passing through the exchanger 34 and that passing through the bypass duct 35. For example, as shown in [Fig.2], the motor 64 actuates the flaps of one of the shutters, here the shutter 62, which has the effect of simultaneously actuating the flaps of the other shutter, here the shutter 61, since the shutters are mechanically linked.For example, engine 64 is located in compartment 32, near inlet 52.

[0067] Preferably, the recuperator 3 comprises a return spring, exerting a return force on the closure system 36. Under the effect of this return force, when the recuperator is in the bypass configuration, or possibly in the partial recovery configuration, the return spring tends to actuate the closure system 36 to put the recuperator 3 in the maximum recovery configuration where the flow F1 passes through the exchanger 34 without passing through the bypass conduit 35.

[0068] In the present example, the return spring is integrated into the motor 64, in that the motor constitutes a spring return servomotor.

[0069] Alternatively, it may be provided that the return spring is separate from the motor 64. In this case, for example, the return spring is in the form of a spiral spring, one end of which is attached to an output shaft of the motor 64, and another end of which is attached to a fixed part, for example the casing of the motor 64 or a support plate of the motor 64, so as to elastically apply a torque to the output shaft, tending to rotate the output shaft of the motor 64 in a direction which drives the closure system 36 towards the recovery configuration.

[0070] Regardless of the structure and arrangement of the return spring, in the event of a power outage, which may occur in the event of a fire in the building, the closure system 36 automatically switches to the maximum recovery configuration under the action of the return spring. In other words, the bypass duct 35 is closed while the exchanger 34 is open, so that the entire flow F1 passes through the exchanger 34 and not the bypass duct 35. Thanks to this arrangement, it is certain that, in the event of a problem such as a breakdown or a fire, the flow F1 can pass through the exchanger 34 which has been cleaned by the sprayer 37, while the bypass duct 35 potentially presents a risk of being clogged, in particular in the case where cleaning of the bypass duct 35 by the sprayer 37 is not provided.

[0071] Preferably, the recuperator 3 also comprises one or more temperature sensors.

[0072] For example, the recuperator 3 comprises a temperature sensor 72 which measures the temperature of the flow F1, while the flow F1 enters the recuperator 3. Preferably, the sensor 72 is arranged in the compartment 32. Preferably, the sensor 72 is in the form of a thermocouple, a thermostat or a temperature probe.

[0073] For example, the recuperator 3 comprises a temperature sensor 70 which measures the temperature of the flow F2, while the flow F2 enters the recuperator 3. Preferably, the sensor 70 is arranged in the compartment 30. Preferably, the sensor 70 is in the form of a thermocouple, a thermostat or a temperature probe.

[0074] For example, the recuperator 3 comprises a temperature sensor 73 which measures the temperature of the flow F2, while the flow F2 leaves the exchanger 34. Preferably, the sensor 73 is arranged in the compartment 31. Preferably, the sensor 73 is in the form of a thermocouple, a thermostat or a temperature probe.

[0075] It is also possible to provide one or more temperature sensors outside the recuperator 3, for example inside the building, in particular in the kitchen 2, such as on the hood 6.

[0076] Preferably, the recuperator 3 comprises a control unit 74, which is configured to control the motor 64. The control unit 74 can thus control the shutter system 36 by controlling the motor 64. Optionally, the control unit 74 can control the degree of shuttering applied by the shutter system to adjust the proportion of flow F1 passing through the exchanger and passing through the bypass duct. It is also possible to provide for the control unit 74 to control a power supply supplying the motor 64, so as to be able to activate and cut off the power supply.

[0077] For example, the control unit 74 is arranged in the maintenance compartment 76. The control unit 74 is in the form of an electronic unit, executing a computer program using a processor or other computer or electronic means, and having a human-machine interface or being able to be coupled to a human-machine interface, so that a person can adjust, control and / or monitor the unit 74. The control unit 74 is connected to the aforementioned temperature sensor(s), for example by wired or wireless connection, to receive the temperature information. Here the control unit 74 receives the temperature information of the flows F1 and / or F2 from the installed sensor(s), for example the sensors 70, 72 and / or 73, as well as the temperature information from the sensor installed in the kitchen 2, if provided.Based on this temperature information, the control unit 74 controls the motor 64, to automatically switch the recuperator 3 between the recovery and bypass configurations, depending on the measured temperatures. Preferably, in the recovery configuration, the control unit 74 controls the motor 64 to vary the degree of closure and thus adjust the proportion of flow F1 passing respectively through the exchanger 34 and the conduit 35.

[0078] During normal use of the recuperator 3, the motor 64 is powered by an electrical power supply for its operation. Advantageously, the control unit 74 is designed to cut off the electrical power supply when the temperature of the flow F1 measured by the sensor 72 exceeds a predetermined threshold value, possibly for a predetermined duration, and / or when a fire is detected. For example, the threshold value is set to 70°C, which corresponds to a detection of a fire. Indeed, in the event of a fire in the kitchen 2 or in the building, the flow F1 is likely to be loaded with fire fumes which are hotter than the usual stale air, in particular hotter than kitchen fumes. The detection of the fire can also be carried out by a sensor or device other than the sensor 72, possibly placed outside the recuperator 3.Fire detection can also be done by a person, who sends the information to the control unit 74, triggering a fire alarm.

[0079] The power supply being thus cut off, the motor 64 is advantageously deactivated and therefore disengaged, so that the shutter system 36 is mechanically put into recovery configuration by the return spring, by elasticity of said return spring. In other words, in the event of a fire, the recuperator 3 automatically puts itself into maximum recovery configuration which, in this case, is a safety configuration.

[0080] Preferably, in the recovery configuration, it is provided that the control unit 74 automatically controls the adjustment of the closure system 36, by controlling the motor 64, as a function of a measurement made by a sensor, in particular a temperature measurement. The closure system 36 thus controlled determines the ratio between the first portion of the flow F1 passing through the exchanger 34 and the second portion of the flow F1 passing through the bypass duct 35, by partial closure of the inlet 42 and the inlet 52, with a desired ratio between the respective degree of closure of these inlets 42 and 52. By thus adjusting the portion of the flow F1 passing through the exchanger 34, the control unit 74 makes it possible to influence the temperature of the air flow F2 at the outlet of the exchanger 34, by heat exchange between the flows F1 and F2.

[0081] According to a preferred example, the control unit 74 controls the adjustment of the closure system 36 as a function of the temperature measured by the sensor 73. In this case, for example, the control unit 74 can control the adjustment of the closure system 36 to obtain, at the sensor 73, a setpoint temperature value and / or according to a predetermined or calculated setpoint temperature curve. If the temperature obtained at the sensor 73 is different from the setpoint temperature value or if this setpoint temperature value changes, the control unit 74 can control a modification of the adjustment of the closure system 36. Preferably, the control unit 74 can go so far as to put the recuperator 3 in the maximum recovery configuration and even in the bypass configuration.

[0082] Preferably, the control of the adjustment of the shutter system 36 is carried out during normal use of the heat recovery unit 3, in particular outside the detection of a fire or crossing of the threshold value measured by the sensor 72.

[0083] Grease filters may be provided in compartment 32 and / or compartment 33, to reduce fouling of exchanger 34 and / or duct 35, and / or to capture grease transported by flow F1 so that it is not released into the atmosphere outside the building. Filters may also be provided in the other compartments 30 and / or 31 for air flow F2.

[0084] Any feature described above for one embodiment or variant may be implemented in the other embodiments and variants described above, as far as technically possible.

Claims

1. Claims Heat recovery unit (3), for a ventilation installation (1) of a kitchen (2), the heat recovery unit (3) comprising: • a heat exchanger (34); • an insufflation inlet (20), which opens outside the heat recovery unit (3); • an insufflation outlet (21), which opens outside the heat recovery unit (3) and which is fluidically connected to the insufflation inlet (20) via the heat exchanger (34), so that a flow of insufflated air (F2) circulates from the insufflation inlet (20) to the insufflation outlet (21) via the heat exchanger (34); • an inlet compartment (32), which opens onto the heat exchanger (34); • an extraction inlet (22), which opens outside the heat recovery unit (3) and into the inlet compartment (32) to be fluidically connected to the heat exchanger (34) via the inlet compartment (32) when the heat recovery unit (3) is in a recovery configuration; • an extraction outlet (23), which opens outside the heat recovery unit (3) and which is fluidically connected to the inlet compartment (32) via the heat exchanger (34) when the heat recovery unit (3) is in the recovery configuration, so that a flow of stale air (F1), in particular loaded with grease and / or water vapor, circulating from the extraction inlet (22) to the extraction outlet (23), passes through the inlet compartment (32) then the heat exchanger (34) to exchange heat with the flow of air blown (F2) into the heat exchanger (34); and • a sprayer (37), arranged in the inlet compartment (32), capable of spraying a cleaning product to clean the heat exchanger (34) of fouling caused by the flow of stale air (Fl); • a bypass duct (35), arranged against the heat exchanger (34), the extraction inlet (22) being fluidically connected to the extraction outlet (23), successively via the inlet compartment (32) and the bypass duct (35), when the heat recovery unit (3) is in a bypass configuration; • a sealing system (36), which: • in the recovery configuration, fluidly connects the inlet compartment (32) to the heat exchanger (34), so that the stale air flow (Fl) circulates in the heat exchanger (34), and • in the bypass configuration, fluidly separates the inlet compartment (32) from the heat exchanger (34) and fluidly connects the extraction inlet (22) to the bypass duct (35), so that the stale air flow (Fl) circulates in the bypass duct (35) without circulating in the heat exchanger (34); and • a return spring, exerting a return force on the closure system (36), tending to actuate the closure system (36) to put the heat recovery unit (3) in recovery configuration, when the heat recovery unit (3) is in bypass configuration.

2. Heat recovery unit (3) according to claim 1, wherein: • the heat exchanger (34) comprises a primary inlet (42), fluidly connecting the inlet compartment (32) with the heat exchanger (34) when the heat recovery unit (3) is in the recovery configuration; and • the bypass duct (35) comprises a bypass inlet (52), fluidly connecting the inlet compartment (32) with the bypass duct (35) when the heat recovery unit (3) is in the bypass configuration. the primary inlet (42) and the bypass inlet (52) are adjacent and arranged in the same plane.

4. A heat recovery unit (3) according to claim 3, wherein the closure system (36) comprises a first closure member (61), for selectively closing the primary inlet (42), and a second closure member (62), for selectively closing the bypass inlet (52), the first closure member (61) and the second closure member (62) being mechanically linked, such that when the first closure member (61) is in an open position, the second closure member (62) is in a closed position and such that when the first closure member (61) is in a closed position, the second closure member (62) is in an open position.

5. Heat recovery unit (3) according to claim 4, wherein the first shutter (61) is constituted by a first set of shutters and the second shutter (62) is constituted by a second set of shutters.

6. Heat recovery unit (3) according to any one of the preceding claims, further comprising a motor (64), for actuating the shutter system (36) and thus selectively putting the heat recovery unit (3) into recovery configuration and into bypass configuration.

7. Heat recovery unit (3) according to any one of the preceding claims, further comprising a control unit (74), which is configured to put the heat recovery unit (3) in a maximum recovery configuration, where the shutter system (36) fluidically separates the extraction inlet (22) from the bypass duct (35) so that the stale air flow (Fl) does not circulate in the bypass duct (35), when the temperature measured by a temperature sensor (72) of the stale air flow (Fl) exceeds a predetermined threshold value and / or when a fire is detected.

8. Heat recovery unit (3) according to claim 7, wherein: • in the recovery configuration, the closure system (36) is configured to fluidically connect the inlet compartment (32) to the bypass duct (35) so that, while a first part of the stale air flow (F1) circulates in the heat exchanger (34), a second part of the stale air flow (F1) circulates in the bypass duct (35), the closure system (36) being configured to allow a adjusting a ratio between the first part and the second part of the stale air flow (Fl); and • the control unit (74) is configured to control the shutter system (36) to adjust said ratio, based on a measurement carried out by a sensor (73).

9. A heat recovery unit (3) according to any preceding claim, wherein the heat recovery unit (3) is a static heat recovery unit.

10. Ventilation installation (1) for a kitchen (2), comprising: • the heat recovery unit (3) according to any one of the preceding claims; • an extraction motor-fan unit (4), arranged outside the heat recovery unit (3) and being fluidically connected to the extraction outlet (23), for circulating the stale air flow (F1); and • an insufflation motor-fan unit (5), arranged outside the heat recovery unit (3) and being fluidically connected to the insufflation outlet (21), for circulating the insufflated air flow (F2).

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