Thermal regulation system

Abstract

Title: Thermal regulation system The subject of the invention is a thermal regulation system (1), in particular configured to be on board a vehicle, comprising: a refrigerant circuit (50) configured to use a refrigerant, in particular of the flammable type, for example a hydrocarbon refrigerant, in particular propane, an enclosure (30) in which the refrigerant circuit (50) is placed, the enclosure being provided with sealed walls (31) and a vent (32) configured to allow the gas present in the enclosure to exit to the outside of the enclosure through this vent (32), in particular when the pressure in the enclosure reaches a predetermined pressure threshold associated with the vent. Figure for the abstract: Fig. 1

Description

Title of the invention: Thermal regulation system

[0001] The present invention relates to a thermal regulation system with a refrigerant circuit configured to use a refrigerant, in particular of the flammable type, for example a hydrocarbon type refrigerant, in particular propane (also designated as refrigerant fluid R290).

[0002] Patent application JP29704297A (or JP11132595) describes a vehicle air conditioning unit operating with a refrigeration cycle using a refrigerant such as propane. This patent application recommends carrying out propane leak detection.

[0003] The present invention aims to improve the safety of devices using a refrigerant, in particular of the flammable type, for example a hydrocarbon type refrigerant.

[0004] The invention thus relates to a thermal regulation system, in particular configured to be installed on a vehicle, comprising: - a refrigerant circuit configured to use a refrigerant, in particular of a flammable type, for example a hydrocarbon refrigerant, in particular propane, - an enclosure in which the refrigerant circuit is placed, the enclosure being provided with sealed walls and a vent configured to allow the gas present in the enclosure to exit to the outside of the enclosure through this vent, in particular when the pressure in the enclosure reaches a predetermined pressure threshold associated with the vent.

[0005] The invention thus makes it possible to confine / encapsulate the refrigerant circuit in a sealed volume, which makes it possible to reduce the risks of refrigerant leakage (which can present a danger in the case of flammable refrigerant). The enclosure also makes it possible to protect the refrigerant circuit, for example mechanically (for example against shocks) and / or thermally (against a heat source). Generally speaking, the invention allows for improved system safety.

[0006] The walls of the enclosure may, for example, be fireproofed and / or mechanically reinforced, for example using composite material.

[0007] According to one aspect of the invention, the vent is configured to, in particular depending on the pressure inside the enclosure, lower the pressure in the enclosure, in particular the vent being a valve configured to be able to open when the pressure reaches or exceeds the predetermined pressure threshold associated with the vent or the vent being a membrane configured to allow gas to pass when the pressure reaches or exceeds the predetermined pressure threshold associated with the vent.

[0008] According to one aspect of the invention, the vent is configured to prevent a flame formed outside the enclosure from entering the enclosure through the vent.

[0009] According to one aspect of the invention, the thermal regulation system comprises a safety system comprising a refrigerant leak detector, configured to detect a refrigerant leak from the refrigerant circuit, and the safety system is configured to interrupt the circulation of the refrigerant in the refrigerant circuit in the event of a leak being detected by the detector, in particular when the concentration of refrigerant outside the refrigerant circuit reaches or exceeds a predetermined concentration threshold or when the measured pressure reaches or exceeds a predetermined interruption pressure threshold.

[0010] According to one aspect of the invention, the safety system is configured to interrupt the circulation of refrigerant in the refrigerant circuit by stopping a compressor of the refrigerant circuit.

[0011] According to one aspect of the invention, the refrigerant circuit is configured to be segmentable so as to obtain at least two refrigerant circuit segments which are isolated from each other when a refrigerant leak is detected.

[0012] According to one aspect of the invention, the refrigerant circuit comprises one or more valves configured to segment the refrigerant circuit into different segments, in particular at least one expansion valve or an open closed expansion valve or open expansion valve.

[0013] According to one aspect of the invention, the thermal regulation system comprises a hydrocarbon adsorption or absorption device configured to adsorb or absorb hydrocarbon present in the enclosure.

[0014] According to one aspect of the invention, the enclosure contains an atmosphere inert to the refrigerant.

[0015] According to one aspect of the invention, the enclosure also receives, in addition to the refrigerant circuit, a heat transfer fluid circuit.

[0016] According to one aspect of the invention, the heat transfer fluid circuit comprises an expansion tank, and a refrigerant leak detector is preferably placed in the enclosure, in particular to detect the passage of refrigerant through a vent of the expansion tank.

[0017] The invention also relates to a method for protecting a thermal regulation system comprising a refrigerant circuit using a refrigerant, in particular a flammable refrigerant, for example of the hydrocarbon type, in particular propane, the method comprising the following step: - place the refrigerant circuit in an enclosure provided with sealed walls and a vent configured to allow the gas present in the enclosure to escape to the outside of the enclosure through this vent, in particular when the pressure in the enclosure reaches a predetermined pressure threshold associated with the vent.

[0018] The invention also relates, independently or in combination with the above, to a thermal regulation system, in particular configured to be installed on a vehicle, comprising: - a refrigerant circuit configured to use a refrigerant, in particular of a flammable type, for example a hydrocarbon refrigerant, in particular propane, - a safety system configured to interrupt the circulation of refrigerant in the refrigerant circuit in the event of a risk of refrigerant leakage.

[0019] Advantageously, the safety system comprises a refrigerant leak detector, configured to detect a refrigerant leak from the refrigerant circuit, and the safety system is configured to interrupt the circulation of the refrigerant in the refrigerant circuit in the event of a leak being detected by the detector, in particular when, outside the refrigerant circuit, the refrigerant concentration reaches a predetermined concentration threshold or when the measured pressure reaches a predetermined interruption pressure threshold.

[0020] Advantageously, the thermal regulation system is configured to interrupt the circulation of the refrigerant in the refrigerant circuit in the event of detection of a leak when the concentration of refrigerant outside the refrigerant circuit reaches a predetermined concentration threshold or when the pressure measured outside the refrigerant circuit reaches a predetermined interruption pressure threshold. In other words, the detection of a leak is proven (called a "leak detected" situation) when the concentration of refrigerant outside the refrigerant circuit reaches a certain concentration threshold or when the pressure measured outside the refrigerant circuit reaches a certain predetermined interruption pressure threshold. These thresholds are called leak detection thresholds, which trigger the interruption of the circulation of refrigerant in the circuit.

[0021] The leak detection thresholds indicated above are chosen according to the lower explosive limit (also designated by the acronym LEL). The lower explosive limit (LEL) of a combustible gas or vapor designates the minimum concentration above which the substance can be ignited. The lower explosive limit (LEL) is expressed as a percentage (%) of volume in air. Below the lower explosive limit (LEL), the mixture is too lean in fuel to initiate any reaction. In an exemplary embodiment of the invention, the leak detection threshold, or concentration threshold, is less than or equal to 50% of the lower explosive limit (LEL) of propane, which is approximately 2.2% or 2.3%. For example, when the propane concentration reaches 1.1% (i.e. 50% of 2.2%), it is considered that there is a leak and the safety system activates implements the interruption of the circulation of refrigerant in the refrigerant circuit. An alarm trigger threshold (for example a visual or audible alarm) can be set below the leak detection threshold, or concentration threshold, for example with a margin of 20%. In the example given, with a margin of 20%, the alarm trigger threshold can be 0.88% in propane concentration (0.88%=l.l%*(l-20%)). Thus an audible alarm can be triggered as soon as the propane concentration reaches 0.88%.

[0022] According to one aspect of the invention, the safety system is configured to interrupt the circulation of refrigerant in the refrigerant circuit by stopping a compressor of the refrigerant circuit. It is thus possible to limit / slow down the refrigerant leak. Conversely, if the compressor continues to operate while a leak occurs, then the leak continues, or even intensifies, because the compressor continues to maintain the circulation of refrigerant.

[0023] According to one aspect of the invention, the refrigerant circuit is configured to be able to be segmented so as to obtain at least two refrigerant circuit segments which are isolated from each other when a refrigerant leak is detected.

[0024] Thus, in the event of a leak, the refrigerant, for example propane, cannot pass from one segment to the other, so that, if the leak concerns one of the segments, the quantity of refrigerant which leaks is limited to the quantity of refrigerant present in this segment. The refrigerant contained in the other segment(s) remains trapped and cannot leak. This makes it possible to reduce the quantity of refrigerant which leaks out of the refrigerant circuit.

[0025] According to one aspect of the invention, the refrigerant circuit comprises one or more valves configured to segment the refrigerant circuit into different segments.

[0026] According to one aspect of the invention, the number of valves is less than the number of segments, for example being equal to the number of segments minus one. Alternatively, the number of valves is equal to the number of segments.

[0027] By closing the valve, it is possible to isolate two segments of the circuit on either side of this valve.

[0028] In particular, at least one of the segments is closed by two valves at two ends of this segment.

[0029] According to one aspect of the invention, the number of segments is chosen so that the mass of refrigerant in each segment is less than a predetermined mass value, in particular less than 150 g.

[0030] Thus when the segments are isolated from each other, the mass of refrigerant which can leak is less than the predetermined mass value.

[0031] When the refrigerant is propane, each segment is configured to contain less than 150 g of refrigerant.

[0032] In another exemplary embodiment of the invention, for a refrigerant (named "a") which has a lower explosive limit LEL(a) and propane a LEL of 2.2%, then the mass of refrigerant "a" in each segment is chosen to be less than (150*LEL(a) / 2.2%). The more explosive a refrigerant is (therefore the lower the LEL value), the less refrigerant each segment must contain by mass.

[0033] For a total mass of refrigerant (propane) of 400 g, the number of segments is chosen to be 3 so that the mass in each segment is less than or equal to 150 g.

[0034] According to one aspect of the invention, the valve(s) used to segment the refrigerant circuit may comprise at least one expansion valve (or in English “Expansion valves” or EXV).

[0035] According to one aspect of the invention, the expansion valve is a closed open expansion valve (CEO).

[0036] According to one aspect of the invention, the expansion valve is an open expansion valve (or in English “Open expansion valve” or CO).

[0037] According to one aspect of the invention, the leak detector comprises a sensor arranged outside the refrigerant circuit and configured to detect the presence of the refrigerant.

[0038] According to one aspect of the invention, the sensor is a hydrocarbon sensor, in particular a propane sensor. This type of sensor allows direct detection of a leak, in particular by making it possible to determine a hydrocarbon concentration.

[0039] According to one aspect of the invention, the refrigerant circuit comprises a refrigerant reserve and the leak detector is configured to detect a drop in level in this refrigerant reserve.

[0040] This detection is an indirect detection because the occurrence of a refrigerant leak appears as the consequence of the drop in level in this refrigerant reserve.

[0041] According to one aspect of the invention, the refrigerant circuit is placed in an enclosure.

[0042] According to one aspect of the invention, the enclosure is provided with sealed walls and a vent configured to allow the gas present in the enclosure to exit to the outside of the enclosure through this vent, in particular when the pressure in the enclosure reaches a predetermined pressure threshold associated with the vent. The predetermined interruption pressure threshold is identical to or different from the pressure threshold associated with the vent. In particular, the predetermined interruption pressure threshold is less than or equal to the pressure threshold associated with the vent.

[0043] According to one aspect of the invention, this vent is configured to be controlled, in particular as a function of the pressure inside the enclosure, with a view to reducing the pressure in the enclosure.

[0044] According to one aspect of the invention, the vent is a valve configured to be able to open when the pressure reaches the predetermined pressure threshold associated with the vent.

[0045] According to one aspect of the invention, the vent is a membrane configured to allow gas (which may then contain gaseous hydrocarbon) to pass when the pressure reaches the predetermined pressure threshold associated with the vent.

[0046] According to one aspect of the invention, the vent is formed from porous bronze.

[0047] The vent is advantageously configured to prevent a flame formed outside the enclosure from entering the enclosure through the vent.

[0048] In particular, the vent is configured to prevent the flame from rising towards the interior of the enclosure, thereby blocking propagation of the flame in the enclosure.

[0049] For this purpose, the vent is configured to have an IEMS value (maximum experimental safety gap) which is defined as the maximum thickness of the air layer between two parts of an internal chamber of a test apparatus which, when the internal mixture is ignited, prevents the ignition of the same external gas mixture through a shoulder of given length. The IEMS value is expressed in millimeters. In the present invention, for the case of propane, the vent is characterized by a ratio of hydraulic diameter divided by the wall thickness (equivalent to the length of the vent) which is less than 3.6%.

[0050] According to one aspect of the invention, the thermal regulation system comprises a hydrocarbon adsorption or absorption device configured to adsorb or absorb hydrocarbon present in the enclosure. In particular, the hydrocarbon adsorption or absorption device is in the enclosure.

[0051] According to one aspect of the invention, the activated carbon may be of reference RX 1.5, or CNR-115, or Cu-MOF-74 or Co-MOF-74.

[0052] Other activated carbons that can be used are, for example, those marketed under the name EcoSorb™.

[0053] According to one aspect of the invention, the enclosure contains an atmosphere inert to the hydrocarbon. The inert atmosphere contains nitrogen or argon for example.

[0054] According to one aspect of the invention, the leak detector is placed in this enclosure.

[0055] In particular when the leak detector comprises a gas sensor, the gas sensor (for example propane) is placed inside this enclosure to detect a possible leak.

[0056] According to one aspect of the invention, the system is configured to deliver leak information, for example in the form of an audible or visual alarm, when the gas sensor detects a gas concentration in the interior space of the enclosure which reaches the predetermined concentration threshold, or alarm trigger threshold.

[0057] According to another aspect of the invention, the leak detector may comprise a pressure sensor, and possibly a temperature sensor in addition to the pressure sensor.

[0058] According to one aspect of the invention, the pressure sensor can be placed in the interior space of the enclosure and configured to measure the pressure in this enclosure.

[0059] This pressure sensor makes it possible to detect a possible refrigerant leak from the refrigerant circuit if the measured pressure reaches the predetermined interruption pressure threshold.

[0060] The increase in pressure corresponds to an accumulation of gas (for example propane) in the enclosure.

[0061] Alternatively, the pressure sensor may be configured to measure the pressure in the refrigerant circuit. The pressure sensor is in particular placed in the refrigerant circuit.

[0062] This pressure sensor makes it possible to detect a possible refrigerant leak from the refrigerant circuit if the measured pressure decreases below a predetermined internal pressure threshold.

[0063] The pressure decrease corresponds to a leak of refrigerant (for example propane) outside the refrigerant circuit. The predetermined internal pressure threshold is defined according to the location of the sensor in the circuit (for example upstream or downstream of the compressor.

[0064] The volume of the enclosure is for example between 20 and 25 liters.

[0065] According to one aspect of the invention, the refrigerant circuit comprises at least one compressor, in particular an electric compressor, for compressing the refrigerant and a condenser.

[0066] According to one aspect of the invention, the enclosure also receives, in addition to the refrigerant circuit, at least part of a heat transfer fluid circuit. The heat transfer fluid circuit may be partially outside the enclosure.

[0067] In this case, the refrigerant circuit comprises, in addition to the compressor and the condenser, one or more bi-fluid heat exchangers (also called "Chillers" in English), and the refrigerant circuit and the heat transfer fluid circuit being configured to mutually exchange heat, by the bi-fluid heat exchanger(s) of the refrigerant circuit. The bi-fluid heat exchanger(s) are in particular placed in the enclosure.

[0068] According to one aspect of the invention, the heat transfer fluid circuit comprises a pump (in particular a water pump), an expansion tank (or "surge tank" in English), and at least one single-way valve or one multi-way valve.

[0069] According to one aspect of the invention, the heat transfer fluid circuit comprises a expansion tank, and a refrigerant leak detector is preferably placed in the enclosure, near the expansion tank of the heat transfer fluid circuit.

[0070] The heat transfer fluid circuit (in particular the water circuit) can be used to cool the passenger compartment (via an HVAC), and / or battery modules, and / or the electric motor, and / or even electronic modules.

[0071] According to one aspect of the invention, the heat transfer fluid circuit uses a heat transfer fluid such as glycolated water.

[0072] According to one aspect of the invention, the expansion tank (surge tank) makes it possible to balance the quantity of heat transfer fluid in the heat transfer fluid circuit by making it possible to supply heat transfer fluid in the event of a deficit.

[0073] The refrigerant sensor is preferably placed in the enclosure, near a vent (degassing vent) of the expansion tank (surge tank) of the heat transfer fluid circuit (water circuit).

[0074] According to one aspect of the invention, the vent defines a non-return valve.

[0075] According to one aspect of the invention, the refrigerant sensor is arranged to detect the passage of refrigerant through the vent of the expansion tank (surge tank).

[0076] According to one aspect of the invention, the refrigerant sensor is placed outside of the expansion tank (surge tank), and in particular inside the enclosure which contains the refrigerant circuit and the heat transfer fluid circuit.

[0077] Alternatively, the refrigerant sensor is placed inside the expansion tank (surge tank).

[0078] According to one aspect of the invention, the heat transfer fluid circuit is configured to be able to be segmented to obtain at least two heat transfer fluid circuit segments which are isolated from each other.

[0079] Indeed, the refrigerant can mix with the heat transfer fluid, in particular glycolated water, and leaks can come from this heat transfer fluid circuit, in addition to the refrigerant circuit.

[0080] It may thus be useful to provide the possibility of being able to segment not only the refrigerant circuit but also the heat transfer fluid circuit.

[0081] In another exemplary embodiment of the invention, the safety system is configured to interrupt the circulation of refrigerant in the refrigerant circuit in the event of a vehicle accident or incident to the vehicle.

[0082] For example, in the event of an impact suffered by the vehicle (impact likely to damage the refrigerant circuit and cause a leak in this circuit), the safety system is configured to interrupt the circulation of refrigerant in the refrigerant circuit. In this case, the interruption of the circulation of refrigerant in the circuit does not require prior detection of a refrigerant leak. This automatic interruption, whether there is a leak or not, makes it possible to secure the refrigerant circuit. The safety system safety system may be configured to receive shutdown information, for example following an impact (for example from a vehicle impact sensor), and upon receipt of this shutdown information, the safety system causes the circulation of refrigerant to be interrupted.

[0083] In this case, the safety system is configured to interrupt the circulation of refrigerant in the refrigerant circuit as described further.

[0084] The invention also relates to a method for protecting a thermal regulation system comprising a refrigerant circuit configured to use a refrigerant, in particular a flammable one, for example of the hydrocarbon type, in particular propane, the method comprising the following step: - interrupt the circulation of refrigerant in the refrigerant circuit in the event of a risk of refrigerant leakage, preferably by switching off a compressor in the refrigerant circuit and / or by closing at least one valve in the refrigerant circuit.

[0085] The invention also relates to a thermal regulation system, in particular configured to be installed on a vehicle, comprising: - a refrigerant circuit configured to use a flammable refrigerant, for example a hydrocarbon refrigerant, in particular propane, - an enclosure in which the refrigerant circuit is placed and the enclosure contains an inert atmosphere for the flammable refrigerant, the inert atmosphere containing, for example, nitrogen or argon.

[0086] The invention also relates to a thermal regulation system, in particular configured to be installed on a vehicle, comprising: - a refrigerant circuit configured to use a flammable refrigerant, for example a hydrocarbon refrigerant, in particular propane, - an enclosure in which the refrigerant circuit is placed and the enclosure comprises a device for capturing refrigerant present in the enclosure, in particular the capture device being configured to adsorb or absorb the refrigerant.

[0087] The invention thus relates, independently or in combination with the above, to a thermal regulation system, in particular configured to be installed on a vehicle, comprising: - a refrigerant circuit configured to use a refrigerant, in particular of a flammable type, for example a hydrocarbon refrigerant, in particular propane, - a heat transfer fluid circuit which is configured to exchange heat with the refrigerant circuit, - a leak detector configured to detect the presence of refrigerant in the heat transfer fluid circuit or a refrigerant leak from the heat transfer fluid circuit.

[0088] There is a risk that the refrigerant from the refrigerant circuit will pass into the heat transfer fluid circuit and mix with the heat transfer fluid, in particular glycolated water, and leaks may arise from this heat transfer fluid circuit. The invention makes it possible to detect the presence of refrigerant in the heat transfer fluid and a possible refrigerant leak, which makes it possible to improve the overall safety of the thermal control system.

[0089] According to one aspect of the invention, the thermal regulation system comprises an enclosure in which the refrigerant circuit and at least partly the heat transfer fluid circuit are placed, and the refrigerant leak detector being in particular placed in the enclosure.

[0090] According to one aspect of the invention, the enclosure is provided with sealed walls and a vent configured to allow the gas present in the enclosure to exit to the outside of the enclosure through this vent, in particular when the pressure in the enclosure reaches the predetermined pressure threshold associated with the vent.

[0091] According to one aspect of the invention, the heat transfer fluid circuit comprises an expansion tank.

[0092] According to one aspect of the invention, the expansion tank is in the enclosure.

[0093] According to one aspect of the invention, the refrigerant leak detector comprises a refrigerant sensor or a pressure sensor capable of detecting the presence of refrigerant in the expansion tank.

[0094] Alternatively, the refrigerant leak detector comprises a refrigerant sensor or a pressure sensor capable of detecting the passage of refrigerant into a vent of the expansion tank of the heat transfer fluid circuit, the refrigerant or pressure sensor being placed outside the expansion tank.

[0095] According to one aspect of the invention, the refrigerant circuit comprises one or more bi-fluid heat exchangers, and the refrigerant circuit and the heat transfer fluid circuit being configured to mutually exchange heat, by the bi-fluid heat exchanger(s).

[0096] According to one aspect of the invention, the bi-fluid heat exchangers are arranged in the enclosure.

[0097] According to one aspect of the invention, the thermal regulation system comprises a safety system configured to interrupt the circulation of the heat transfer fluid in the heat transfer fluid circuit in the event of leak detection by the detector, in particular when the quantity of refrigerant leaking from the heat transfer fluid circuit reaches a predetermined threshold or when the pressure measured outside the heat transfer fluid circuit reaches a predetermined cut-off pressure threshold.

[0098] According to one aspect of the invention, the heat transfer fluid circuit is configured to be able to be segmented to obtain at least two heat transfer fluid circuit segments which are isolated from each other.

[0099] It may thus be useful to provide the possibility of being able to segment not only the refrigerant circuit but also the heat transfer fluid circuit.

[0100] The invention also relates to a method for protecting a thermal regulation system comprising a refrigerant circuit using a refrigerant, in particular a flammable refrigerant, for example of the hydrocarbon type, in particular propane, and a heat transfer fluid circuit which is configured to exchange heat with the refrigerant circuit, the method comprising the following step: - detecting the presence of refrigerant in the heat transfer fluid circuit (80) or a leak of refrigerant from the heat transfer fluid circuit (80).

[0101] According to one aspect of the invention, the heat transfer fluid circuit is configured to be used to cool the passenger compartment, and / or battery modules, and / or the electric motor, and / or electronic modules.

[0102] It should be noted that the vent of the expansion tank is separate from the vent of the enclosure.

[0103] According to one aspect of the invention, the enclosure contains an atmosphere inert to the hydrocarbon.

[0104] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and several examples of embodiment given for informational and non-limiting purposes with reference to the appended schematic drawings on the other hand, in which:

[0105] [Fig-1] [Fig.l] is a schematic representation of a regulation system thermal according to an exemplary embodiment of the invention;

[0106] [Fig.2] [Fig.2] is a schematic representation of a control system thermal according to another exemplary embodiment of the invention;

[0107] [Fig.3] [Fig.3] is a schematic representation of a thermal regulation system according to yet another exemplary embodiment of the invention;

[0108] The features, variants and the different embodiments of the invention may be combined with each other, in various combinations, to the extent that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art. of the prior art.

[0109] [Fig.l] shows very schematically a thermal regulation system 1 configured to be installed on a vehicle, comprising a refrigerant circuit 50 configured to use a hydrocarbon-type refrigerant, here propane (also designated as refrigerant fluid R290). The refrigerant circuit 50 is configured to operate as a heat pump.

[0110] The refrigerant circuit 50 comprises an electric compressor 51 configured to compress the refrigerant, and a condenser 52 (here a water condenser) arranged in series with the compressor 51. A degassing bottle 55 is arranged, in a conventional manner, in series with the condenser 52.

[0111] The thermal regulation system 1 also comprises a heat transfer fluid circuit 80 (shown very schematically in [Fig.l]), and several bi-fluid heat exchangers 53 (also called “Chillers” in English) are provided, configured to mutually exchange heat between the refrigerant circuit 50 and the heat transfer fluid circuit 80.

[0112] The heat transfer fluid circuit 80 comprises a water pump 81, an expansion tank 82 (or “surge tank” in English), and a multi-way valve 83.

[0113] The heat transfer fluid circuit 80, here a water circuit (using glycolated water), can be used to cool the passenger compartment via an HVAC 60, and / or to cool battery modules 61, and / or to cool the electric motor 62, and / or to cool electronic modules 63, and / or to cool a cooling module 64.

[0114] The expansion tank 82 makes it possible to balance the quantity of heat transfer fluid in the heat transfer fluid circuit 80 by making it possible to supply heat transfer fluid in the event of a deficit.

[0115] The refrigerant circuit 50 and a part of the heat transfer fluid circuit 80 are placed in an enclosure 30. The bi-fluid heat exchangers 53 and the expansion tank 82 are placed in the enclosure 30.

[0116] The enclosure 30 is provided with sealed walls 31 and a vent 32 configured to allow the gas present in the enclosure 30 to exit to the outside of the enclosure through this vent 32, when the pressure in the enclosure reaches the predetermined pressure threshold associated with the vent. The walls 32 of the enclosure may for example be fireproof and / or mechanically reinforced, for example using composite material.

[0117] The vent 32 is here a valve configured to be able to open when the pressure inside the enclosure 30 reaches the predetermined pressure threshold associated with the vent in order to lower the pressure in the enclosure 30.

[0118] Alternatively, the vent is a membrane configured to allow gas (which may then contain gaseous hydrocarbon) to pass when the pressure reaches the pressure threshold. predetermined associated with the vent. The vent 32 is notably formed from porous bronze.

[0119] In any event, the vent 32 is configured to prevent a flame formed outside the enclosure 30 from entering the enclosure, through the vent 32. In particular, the vent 32 is configured to prevent the flame from rising towards the inside of the enclosure, thus blocking a propagation of the flame in the enclosure. This is particularly advantageous from a safety point of view, by preventing a fire from spreading inside the enclosure 30. For the case of propane, the vent 32 is characterized by a ratio of hydraulic diameter divided by the wall thickness (equivalent to the length of the vent) which is less than 3.6%.

[0120] The thermal regulation system 1 comprises a hydrocarbon adsorption or absorption device 40 configured to adsorb or absorb hydrocarbon present in the enclosure.

[0121] The device 40, for example with activated carbon, comprises several blocks arranged at different locations, within the enclosure 30.

[0122] The enclosure 30 may contain an atmosphere that is inert to the hydrocarbon. The inert atmosphere contains nitrogen or argon, for example. This ensures that the propane does not react chemically with the atmosphere in the enclosure 30, thus preventing, for example, combustion.

[0123] The thermal regulation system 1 comprises a refrigerant leak detector 45 configured to detect a refrigerant leak from the refrigerant circuit 50. The detector 45 is part of a safety system 49 configured to interrupt the circulation of the refrigerant in the refrigerant circuit 50 in the event of a leak being detected by the leak detector 45.

[0124] The leak detector 45 is placed in the enclosure 30, and comprises a gas sensor 46, here a propane sensor.

[0125] The thermal regulation system 1 is configured to deliver leak information, for example in the form of an audible or visual alarm, when the gas sensor 46 detects a concentration of gas in the interior space of the enclosure 30 which reaches the predetermined concentration threshold.

[0126] In another exemplary implementation of the invention, the leak detector 45 may comprise a pressure sensor configured to measure the pressure in the enclosure 30.

[0127] This pressure sensor makes it possible to detect a possible refrigerant leak from the refrigerant circuit if the measured pressure reaches the predetermined interruption pressure threshold. The increase in pressure corresponds to an accumulation of gas (here propane) in the enclosure 30.

[0128] In yet another exemplary implementation of the invention, the pressure sensor may be configured to measure the pressure in the refrigerant circuit 50. The pressure sensor is in particular placed in the refrigerant circuit 50. This pressure sensor makes it possible to detect a possible refrigerant leak from the refrigerant circuit if the measured pressure decreases below a predetermined internal pressure threshold. The decrease in pressure corresponds to a refrigerant leak (here propane) outside the refrigerant circuit. The predetermined internal pressure threshold is defined according to the location of the sensor in the circuit (for example upstream or downstream of the compressor).

[0129] The thermal regulation system 1 is configured to interrupt the circulation of the refrigerant in the refrigerant circuit 50 in the event of detection of a leak, when the concentration of refrigerant outside the refrigerant circuit 50 reaches a predetermined threshold or when the pressure measured outside the refrigerant circuit reaches the predetermined interruption pressure threshold.

[0130] The leak detection thresholds indicated above are chosen based on the lower explosive limit (also referred to by the acronym LEL). The lower explosive limit (LEL) of a combustible gas or vapor refers to the minimum concentration above which the substance can be ignited. The lower explosive limit (LEL) is expressed as a percentage (%) of volume in air. Below the lower explosive limit (LEL), the mixture is too lean in fuel to initiate any reaction. In an exemplary embodiment of the invention, the leak detection threshold, or concentration threshold, is less than 50% of the lower explosive limit (LEL) of propane, which is approximately 2.2% or 2.3%.For example, when the propane concentration reaches 1.1% (i.e. 50% of 2.2%), it is considered that there is a leak and the safety system 49 implements the interruption of the circulation of refrigerant in the refrigerant circuit. An alarm trigger threshold (for example a visual or audible alarm) can be set below the leak detection threshold, or concentration threshold, for example with a margin of 20%. In the example given, with a margin of 20%, the alarm trigger threshold can be 0.88% in propane concentration (0.88%=l.l%*(l-20%)). Thus an audible alarm can be triggered as soon as the propane concentration reaches 0.88%.

[0131] The safety system 49 is configured to interrupt the circulation of the refrigerant in the refrigerant circuit by stopping a compressor 51 of the refrigerant circuit 50. It is thus possible to limit / slow down the refrigerant leak. Conversely, if the compressor 51 continues to operate while a leak occurs, then the leak continues, or even intensifies, because the compressor 51 continues to maintain the circulation of refrigerant.

[0132] The refrigerant sensor 46 is preferably placed in the enclosure 30, near a vent 89 (degassing vent) of the expansion tank 82 of the ca- fluid circuit. carrier 80, and configured to detect the passage of refrigerant through the vent 89 of the expansion tank 82.

[0133] The refrigerant sensor 46 is placed outside the expansion tank 82.

[0134] It is of course possible to provide several refrigerant sensors 46 placed at different locations inside the enclosure 30.

[0135] In the described exemplary implementation, the refrigerant circuit 50 is configured to be segmentable so as to obtain at least two refrigerant circuit segments which are isolated from each other when a refrigerant leak is detected.

[0136] Thus, in the event of a leak, propane cannot pass from one segment to the other, so that if the leak concerns one of the segments, the amount of refrigerant that leaks is limited to the amount of refrigerant present in that segment. The refrigerant contained in the other segment(s) remains trapped and cannot leak. This reduces the amount of refrigerant that leaks out of the refrigerant circuit.

[0137] For this purpose, the refrigerant circuit 50 comprises several valves 70 configured to segment the refrigerant circuit 50 into different segments, for example into 2, 3, 4, 5 or 6 segments.

[0138] By closing one of the valves 70, it is possible to isolate two segments of the circuit on either side of this valve.

[0139] We will now describe in more detail, with reference to FIGS. 2 and 3, these valves 70 and their placement in the refrigerant circuit 50.

[0140] In the example of [Fig.2], a valve 71, in particular of the stop valve type or in English “Shut Off Valve” (SOV), is placed between the compressor 51 and the condenser 52.

[0141] The refrigerant circuit 50 includes an internal heat exchanger 77 (often referred to by the acronym IHX) configured to transfer heat between a low pressure portion and a high pressure portion of the refrigerant circuit 50.

[0142] In this example, the refrigerant circuit 50 comprises two other valves 72 of the closed expansion open valve (or CEO) type.

[0143] Other types of valves may be used, for example an open expansion valve (CO).

[0144] The valves 72 are each placed in series with one of the bi-fluid heat exchangers 53, between the internal heat exchanger 77 and the two bi-fluid heat exchangers 53 (which are mounted in parallel).

[0145] Thus, in the event of a leak, the valves 71 and 72 are closed by the safety system 49 so as to define two segments 90 and 91. The segment 90 corresponds to the parts of the refrigerant circuit 50 between the valve 71 and the valves 72, and the segment 91 corresponds to the parts of the refrigerant circuit 50 between the valves 72 and the valve 71.

[0146] The safety system 49 comprises, for example, control electronics enabling, upon receipt of a safety order, the closing of the valves to be controlled. The safety order is issued when a leak is detected.

[0147] In the example of [Fig.3], a second valve 73, of the shut-off valve type or in English “Shut Off Valve” (SOV), is placed between the degassing bottle 55 and the condenser 52. The degassing bottle 55 is configured to remove moisture from the refrigerant and can also serve as a buffer tank for the refrigerant.

[0148] The compressor 51 may be configured to segment the refrigerant circuit 50 upstream and downstream of the compressor 51. In this case, for the example of [Fig.2], the refrigerant circuit 50 may comprise an additional segment 93 between the compressor 51 and the valve 71. In this case, the refrigerant circuit 50 may be segmented into three segments 90, 91 and 93.

[0149] It is thus possible to form three segments by closing the four valves 71, 72 and 73. These three segments are: - a first segment 94 between valve 71 and valve 73, - a second segment 95 between valve 71 and valves 72, - a third segment 96 between valves 72 and valve 73.

[0150] The invention makes it possible to isolate these three segments 94, 95 and 96, so that in the event of a leak, only one of the segments leaks.

[0151] It is advantageous to position the valves 71 (SOV valves) or 72 (CEO valves) at the locations which have the greatest load, namely around the condenser 52 or, where appropriate, around the condenser 52 and a heat accumulator in the case of an economizer.

[0152] The valves are either placed in a housing (also called a “manifold” in English) or welded to avoid additional leaks linked to their assembly.

[0153] The volume of the enclosure 30 is for example between 20 and 25 liters.

[0154] In an exemplary embodiment of the invention not illustrated, the heat transfer fluid circuit is configured to be able to be segmented to obtain at least two heat transfer fluid circuit segments which are isolated from each other.

[0155] Indeed, the refrigerant can mix with the heat transfer fluid, in particular glycolated water, and leaks can come from this heat transfer fluid circuit, in addition to the refrigerant circuit.

[0156] It may thus be useful to provide the possibility of being able to segment not only the refrigerant circuit but also the heat transfer fluid circuit.

Claims

Claims

1. Thermal regulation system (1), in particular configured to be mounted on a vehicle, comprising: - a refrigerant circuit (50) configured to use a refrigerant, in particular of the flammable type, for example a hydrocarbon refrigerant, in particular propane, - an enclosure (30) in which the refrigerant circuit (50) is placed, the enclosure being provided with sealed walls (31) and a vent (32) configured to allow the gas present in the enclosure to exit to the outside of the enclosure through this vent (32), in particular when the pressure in the enclosure reaches a predetermined pressure threshold associated with the vent.

2. Thermal regulation system according to the preceding claim, in which the vent (32) is configured to, in particular depending on the pressure inside the enclosure (30), lower the pressure in the enclosure, in particular the vent being a valve configured to be able to open when the pressure reaches or exceeds the predetermined pressure threshold associated with the vent or the vent being a membrane configured to allow gas to pass when the pressure reaches or exceeds the predetermined pressure threshold associated with the vent.

3. A thermal control system according to one of the preceding claims, wherein the vent (32) is configured to prevent a flame formed outside the enclosure from entering the enclosure, through the vent (32).

4. Thermal regulation system according to one of the preceding claims, comprising a safety system (49) comprising a refrigerant leak detector (45), configured to detect a refrigerant leak from the refrigerant circuit (50), and the safety system (49) is configured to interrupt the circulation of the refrigerant in the refrigerant circuit (50) in the event of leak detection by the detector, in particular when the concentration of refrigerant outside the refrigerant circuit (50) reaches or exceeds a predetermined concentration threshold or when the pressure measured outside the refrigerant circuit (50) reaches or exceeds a predetermined interruption pressure threshold.

5. Thermal regulation system according to the preceding claim, wherein the safety system (49) is configured to interrupt the circulation of refrigerant in the refrigerant circuit (50) by stopping a compressor (51) of the refrigerant circuit (50).

6. Thermal control system according to one of the preceding claims, wherein the refrigerant circuit (50) is configured to be able to be segmented so as to obtain at least two refrigerant circuit segments (50) which are isolated from each other when a refrigerant leak is detected.

7. Thermal regulation system according to the preceding claim, wherein the refrigerant circuit (50) comprises one or more valves configured to segment the refrigerant circuit (50) into different segments (90, 91), in particular at least one expansion valve or an open closed expansion valve or open expansion valve.

8. Thermal regulation system according to one of the preceding claims, in which the thermal regulation system comprises a hydrocarbon adsorption or absorption device (40) configured to adsorb or absorb hydrocarbon present in the enclosure (30).

9. Thermal control system according to one of the preceding claims, in which the enclosure (30) contains an atmosphere inert to the refrigerant.

10. Thermal regulation system according to one of the preceding claims, in which the enclosure (30) also receives, in addition to the refrigerant circuit (50), at least part of a heat transfer fluid circuit (80).

11. Thermal regulation system according to the preceding claim, in which the heat transfer fluid circuit comprises an expansion tank (82), and a refrigerant leak detector (46) is preferably placed in the enclosure, in particular to detect the passage of refrigerant through a vent of the expansion tank.

12. Method for protecting a thermal regulation system comprising a refrigerant circuit (50) using a refrigerant, in particular flammable, for example of the hydrocarbon type, in particular propane, the method comprising the following step: - placing the refrigerant circuit (50) in an enclosure (30) provided with sealed walls (31) and a vent (32) configured to allow the gas present in the enclosure to exit to the outside of the enclosure through this vent (32), in particular when the pressure in the enclosure reaches a predetermined pressure threshold associated with the vent.

Images