Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
  • F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
  • F28D1/04—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits
  • F28D1/053—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being straight
  • F28D1/0535—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being straight the conduits having a non-circular cross-section
  • F28D1/05366—Assemblies of conduits connected to common headers, e.g. core type radiators
  • F28D1/05375—Assemblies of conduits connected to common headers, e.g. core type radiators with particular pattern of flow, e.g. change of flow direction
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
  • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
  • H01L23/367—Cooling facilitated by shape of device
  • H01L23/3675—Cooling facilitated by shape of device characterised by the shape of the housing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
  • H01L23/42—Fillings or auxiliary members in containers or encapsulations selected or arranged to facilitate heating or cooling
  • H01L23/427—Cooling by change of state, e.g. use of heat pipes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
  • H01L23/46—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements involving the transfer of heat by flowing fluids
  • H01L23/467—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements involving the transfer of heat by flowing fluids by flowing gases, e.g. air
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/0001—Technical content checked by a classifier
  • H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Definitions

• Heat exchanger with at least two passes and air conditioning loop including such a heat exchanger is provided.
• the invention is in the field of heating, ventilation and / or air conditioning equipment equipping a motor vehicle. It relates to a heat exchanger integrated in an air conditioning loop forming part of such an installation. It also relates to such an air conditioning loop.
• a motor vehicle is commonly equipped with a heating, ventilation and / or air conditioning system for modifying the aerothermal parameters of a flow of air diffused inside the passenger compartment of the vehicle.
• the heating, ventilation and / or air-conditioning system consists mainly of a housing that channels the circulation of the airflow to at least one air outlet through which the airflow is distributed outside. from the case to the passenger compartment.
• the housing is for example made of plastic and is housed under a dashboard of the vehicle.
• the heating, ventilation and / or air conditioning installation also includes an air conditioning loop inside which a refrigerant circulates.
• the refrigerant is for example a hydrofluorocarbon, in particular the fluid known under the name R134a, or a compound based on hydrofluoroolefin, especially the fluid known under the name HFO1234yf.
• the present invention also finds application with all refrigerants similar to those mentioned above.
• the air conditioning loop includes an external heat exchanger placed at the front of the vehicle to exchange heat with a flow of air outside the vehicle.
• the external heat exchanger is traversed by the outside air but is not in contact with the air flow intended to be distributed in the passenger compartment of the vehicle.
• the outdoor heat exchanger can be an exchanger comprising at least two passes, that is to say an exchanger comprising at least two series of tubes, the refrigerant flowing successively in a first direction inside a first series of tubes, then in a reverse direction in the first direction inside a second series of tubes.
• the refrigerant circulates successively inside a first compartment of a first manifold, through the first series of tubes, a second collector, through the second set of tubes, a second compartment of the first manifold to be finally discharged out of the outdoor heat exchanger.
• the first compartment is juxtaposed to the second compartment being sealed relative to each other.
• the first manifold and the second manifold are each provided at a respective lateral end of the heat exchanger and the tubes are arranged between the manifolds parallel to each other.
• EP 1 980 81 1 which describes a heat exchanger of the aforementioned type.
• the air conditioning loop can be arranged to operate either in "heating mode", allowing a heating of the air flow via a heat exchanger that includes the air conditioning loop operating as a condenser, or in "cooling mode", allowing a cooling of the air flow via a heat exchanger that also includes the air conditioning loop operating as an evaporator.
• the outdoor heat exchanger behaves like an evaporator.
• the coolant heats up by capturing calories carried by the outside air flow.
• the outdoor heat exchanger behaves like a condenser.
• the refrigerant cools by giving calories to the outside air.
• the air conditioning loop comprises a bypass duct arranged in parallel with the evaporator.
• the coolant always circulates, in "heating mode” and “cooling mode”, in the same direction inside the air conditioning loop, and in particular inside the heat exchanger. outside.
• the air conditioning loop comprises a four-way valve capable of reversing the direction of circulation of the refrigerant inside the external heat exchanger. It follows from these provisions that according to the direction of circulation of the refrigerant inside the external heat exchanger, the refrigerant circulates either through the first series of tubes and then through the second series of tubes, either through the second set of tubes then through the first set of tubes.
• the designers of such heat exchangers wish to have an optimized heat exchanger allowing satisfactory heat exchanges, whatever the mode of operation of the air conditioning loop and whatever the direction of circulation of the refrigerant fluid within the outdoor heat exchanger.
• a general problem consists in determining an optimal arrangement of such a heat exchanger which is able to allow the most satisfactory heat exchange possible, that the heat exchanger behaves like an evaporator or a condenser , whatever the direction of circulation of the refrigerant inside the heat exchanger and whatever the refrigerant used.
• the object of the present invention is to provide a heat exchanger integrated in an air conditioning loop of a heating, ventilation and / or air conditioning of a motor vehicle, the heat exchanger being optimized to allow transfers thermal conditions between a refrigerant circulating inside the air conditioning loop and a flow of air outside the vehicle in contact with the heat exchanger, the refrigerant being in particular a hydrofluorocarbon, in particular the fluid known under the name R134a, or a compound based on hydrofluoroolefin, especially the fluid known under the name HFO1234yf, the air conditioning loop being capable of operating in "cooling mode" and " heating mode ", and the flow direction of the coolant being able to be reversed inside the heat exchanger according to the operating mode of the air conditioning loop.
• the refrigerant being in particular a hydrofluorocarbon, in particular the fluid known under the name R134a, or a compound based on hydrofluoroolefin, especially the fluid known under the name HFO1234yf
• the air conditioning loop
• the heat exchanger of the present invention is a heat exchanger with at least two passes, preferably two passes, comprising N tubes divided into two series of tubes, including a first series comprising N1 tubes between a first collector and a second one. collector, and a second series comprising N2 tubes between the second collector and a third collector.
• An N1 / N ratio is between 15% and 50%.
• the ratio N1 / N is between 35% and 50%, preferably between 40% and 50%.
• the ratio N1 / N is for example of the order of or equal to 35%, or 40%, or 45% or 50%.
• the ratio N1 / N is between 15% and 35%, preferably between 15% and 25%.
• the ratio N1 / N is for example of the order of or equal to 15% or 20%.
• the first collector comprises a first compartment and a second compartment, the third collector being formed by the second compartment of the first collector.
• An air conditioning loop of the present invention comprises a heat exchanger as defined above.
• FIGS. 1 and 2 are diagrammatic illustrations of a first alternative embodiment of an air conditioning loop according to the present invention according to two respective modes of operation,
• FIGS. 3 and 4 are schematic illustrations of a second alternative embodiment of an air conditioning loop according to the present invention according to two respective modes of operation
• FIGS. 5 and 6 are diagrammatic illustrations of a heat exchanger according to the present invention of the first and second embodiments represented in FIGS. 1 to 4,
• FIGS. 7 to 10 are graphical representations of the evolution of a power exchanged between a first type of refrigerant circulating inside the heat exchanger of FIGS. 5 and 6 and an outside air flow therethrough.
• the heat exchanger according to various arrangements of the heat exchanger,
• FIGS. 11 and 12 are graphical representations of the thermal performance evolution of the heat exchanger according to various arrangements of the heat exchanger
• FIGS. 13 to 14 are graphical representations of the evolution of a power exchanged between a second type of refrigerant fluid circulating inside the heat exchanger shown in FIGS. 5 and 6 and an outside air passing through the heat exchanger according to various arrangements of the heat exchanger.
• FIG. 15 is a graphical representation of the thermal performance evolution of the heat exchanger according to various arrangements of the heat exchanger.
• Figures 1 to 4 are respective schematic illustrations of a first embodiment and a second alternative embodiment of an air conditioning loop according to the present invention according to two respective modes of operation.
• a motor vehicle is equipped with a heating, ventilation and / or air conditioning system for modifying the aerothermal parameters of an air flow distributed inside the passenger compartment. of the vehicle.
• the heating, ventilation and / or air conditioning installation consists mainly of a housing 1 made of plastic and housed under a dashboard of the vehicle.
• the heating, ventilation and / or air conditioning system is intended to channel the circulation of an air flow 2 from at least one air inlet to at least one air outlet through which the flow air 2 is diffused outside the housing 1 of the heating, ventilation and / or air conditioning system in the passenger compartment of the vehicle.
• the heating, ventilation and / or air conditioning installation also comprises an air conditioning loop. 3 inside which circulates a refrigerant fluid FR in a direction of circulation 4.
• the refrigerant fluid FR is for example a hydrofluorocarbon, especially the fluid known under the name R134a, or a compound based on hydrofluoroolefin, in particularly the fluid known under the name HFO1234yf, or any other similar refrigerant fluid.
• the air conditioning loop 3 comprises a compressor 5 capable of compressing the refrigerant fluid FR, an external heat exchanger 6 capable of exchanging calories with a flow of air outside the vehicle 7 and an accumulator 8.
• the accumulator 8 is disposed directly upstream of the compressor 5 in the direction of circulation 4 of the refrigerant fluid FR inside the air conditioning loop 3 to collect the cooling fluid FR in the liquid state. .
• the external heat exchanger 6 is disposed at the front of the vehicle to exchange heat with the outside air flow 7 which passes therethrough.
• the external heat exchanger 6 is not in contact with the air flow 2 intended to be diffused into the passenger compartment of the vehicle as a result of its circulation inside the housing 1.
• air conditioning 3 comprises an indoor heat exchanger 9 housed inside the housing 1 and through which the air stream 2 to change the aerothermal parameters of the latter, in particular its temperature.
• FIGS. 1 and 2 A first variant embodiment is illustrated in FIGS. 1 and 2.
• the air conditioning loop 3 comprises a first bypass duct 10.
• the first bypass duct 10 is able to allow or prevent the circulation of the refrigerant fluid.
• FR inside the indoor heat exchanger 9.
• the air conditioning loop 3 also comprises a first expansion member 1 1 disposed between the external heat exchanger 6 and the internal heat exchanger 9 in the direction of circulation 4 of the refrigerant FR inside the air conditioning loop 3.
• the first expansion element 1 1 is more particularly arranged between the first bypass duct 10 and the external heat exchanger 6, upstream of the external heat exchanger 6 in the direction of circulation 4 of the refrigerating fluid FR inside the air conditioning loop 3.
• the air conditioning loop 3 also comprises an internal condenser 12 housed inside the housing 1 and arranged directly downstream of the compressor 5 according to the flow direction 4 of the refrigerant fluid FR inside the air conditioning loop 3.
• the internal condenser 12 is intended to cool the refrigerant fluid FR.
• the cooling of the refrigerant fluid FR in the internal condenser 12 causes a heating of the air flow 2 which passes through it.
• the air conditioning loop 3 also comprises a second expansion member 13 interposed between the internal condenser 12 and the external heat exchanger 6.
• the second expansion member 13 is associated with a second bypass duct 14 for circulating the refrigerant FR either through the second expansion member 13 to the external heat exchanger 6, or directly from the internal condenser 12 to the external heat exchanger 6 bypassing the second expansion member 13.
• the air conditioning loop 3 operates according to the first embodiment in "cooling mode".
• the refrigerant fluid FR flows from the compressor 5 to the internal condenser 12, then flows through the second bypass duct 14 to the outdoor heat exchanger 6, which behaves, in this configuration, as a condenser. heating the outside air flow 7, then to the first expansion member 1 1, in which the refrigerant FR undergoes expansion, then to the indoor heat exchanger 9, which behaves, according to this configuration, as an evaporator in cooling the air flow 2, then to the accumulator 8 to return to the compressor 5.
• an external heat exchanger 6 which is configured to give as much heat as possible to the air flow outside 7.
• the air conditioning loop 3 operates according to the first embodiment in "heating mode".
• the refrigerant fluid FR flows from the compressor 5 to the internal condenser 12, then flows through the second expansion member 13, in which the refrigerant FR undergoes expansion, then to the external heat exchanger 6, who behaves, according to this configuration, as an evaporator cooling the outside air flow 7, then flows through the first bypass duct 10, to the accumulator 8 to return to the compressor 5.
• a heat exchanger outside 6 which is configured to capture as much heat as possible to the outside air flow 7.
• the refrigerant fluid FR flows in the same direction through the outdoor heat exchanger 6 regardless of the operating mode of the air conditioning loop 3 ("heating mode” or “cooling mode”), to namely from a first orifice 15 of the external heat exchanger 6, in relation to the second expansion member 13 and the second bypass duct 14, to a second orifice 16 of the external heat exchanger 6, in relation with the first expansion member 1 1 and the first bypass duct 10.
• the first orifice 15 constitutes an inlet for the refrigerant fluid FR inside the heat exchanger. 6 while the second orifice 16 constitutes an outlet of the refrigerant FR outside the external heat exchanger 6.
• the external heat exchanger 6 is a condenser or an evaporator and is characterized by refrigerant fluid densities FR taken at the inlet of the first orifice 15 and at the outlet of the second orifice 16 which differ from one another. Indeed, when the external heat exchanger 6 behaves like a condenser, the refrigerating fluid FR is wholly or partly in the gas phase at the first orifice 15 and is wholly or partly in the liquid phase at the level of the second orifice 16. It follows that the density of the refrigerant FR at the first orifice 15 is less than the density of the refrigerant FR at the second orifice 16.
• the refrigerant FR is a mixture of gaseous phase and liquid phase at the first orifice 15 while the refrigerating fluid FR is, in whole or in part, in the gas phase at the second orifice 16. It follows that the density of the refrigerant FR at the first orifice 15 is greater than the density of the refrigerant FR at the second orifice 16.
• the present invention provides a solution from a main and advantageous feature of the outdoor heat exchanger 6 which is further developed.
• the air conditioning loop 3 comprises a four-way valve 17 able to reverse the flow direction 4 of the refrigerating fluid FR inside the external heat exchanger 6.
• the air conditioning loop 3 comprises an expansion member 18 interposed between the outer heat exchanger 6 and the inner heat exchanger 9, upstream of the inner heat exchanger 9.
• the second variant comprises numerous elements in common with the first embodiment. Accordingly, unless otherwise indicated, these elements have the same characteristics and specificities as those described above. Consequently, they will be identified by the same as that provided in connection with the description of the first variant embodiment.
• the air conditioning loop 3 operates, according to the second embodiment, in "cooling mode".
• the coolant FR flows from the compressor 5 to the four-way valve 17.
• the four-way valve 17 is configured to circulate the coolant FR to the first port 15 of the heat exchanger 6.
• the refrigerating fluid FR passes through the external heat exchanger 6 to the second orifice 16.
• the external heat exchanger 6 behaves as a condenser inside which the cooling fluid FR cools. by giving heat to the outside air flow 7.
• the refrigerant fluid FR flows to the expansion member 18, in which it undergoes a relaxation, then flows through the internal heat exchanger 9, which behaves, according to this configuration, as an evaporator cooling the flow of air 2 which passes through it.
• the refrigerant fluid joins the four-way valve 17 configured to circulate the refrigerant fluid FR to the accumulator 8 and return to the compressor 5.
• an external heat exchanger 6 which is configured so as to give as much heat as possible to the outside air flow 7.
• the air conditioning loop 3 operates, according to the second embodiment, in "heating mode".
• the refrigerant fluid FR flows from the compressor 5 to the 4-way valve 17.
• the four-way valve 17 is configured to circulate the refrigerant fluid FR to the inner heat exchanger 9, which behaves according to this configuration, as a condenser by heating the flow of air 2 which passes through it.
• the coolant FR passes through the expansion member 18 to then enter the interior of the external heat exchanger 6 via the second orifice 16.
• the refrigerant FR passes through the external heat exchanger 6, which in this configuration behaves like an evaporator and is discharged out of the external heat exchanger 6 via the first orifice 15 to join the four-way valve 17 configured to circulate the fluid refrigerant FR to the accumulator 8, then the compressor 5.
• an external heat exchanger 6 which is configured to capture as much heat as possible to the outside air 7.
• the refrigerant fluid FR flows in reversed directions inside the outdoor heat exchanger 6 according to the operating mode of the air conditioning loop 3.
• the refrigerant fluid FR circulates since the first orifice 15, in relation to the four-way valve 17, to a second orifice 16, in relation to the expansion member 18.
• the first orifice 15 constitutes an orifice of FR refrigerant enters the inside of the external heat exchanger 6 while the second port 16 constitutes an outlet of the refrigerant FR outside the heat exchanger. heat 6.
• the refrigerant fluid FR flows from the second orifice 16, in relation to the expansion member 18, to the first orifice 15, in relation with the four-way valve 17.
• the first orifice 15 constitutes an outlet of the refrigerating fluid FR out of the external heat exchanger 6
• the second orifice 16 constitutes an inlet for the refrigerant fluid FR inside the the heat exchanger 6.
• the difference between the passage section of the refrigerant fluid FR at the inlet of the external heat exchanger 6 and the passage section of the refrigerant fluid FR output of the external heat exchanger 6 is not a criterion to take into account since the first port 15 and the second port 16 are either an inlet or an outlet, depending on the configurations.
• the present invention advantageously proposes an external heat exchanger 6 which makes it possible to achieve the best possible performances between, on the one hand, optimized operation in "cooling mode” and “heating mode” and, on the other hand, between two opposite configurations in which the first orifice 15 is either an inlet for the refrigerating fluid FR inside the heat exchanger 6, or an outlet for the refrigerant FR outside the heat exchanger 6, and conversely for the second orifice 16.
• the heat exchanger 6 is a heat exchanger with at least two passes comprising a number N of tubes 19 distributed in at least two sets of tubes 19.
• the example of FIGS. 5 and 6 comprises only two series of tubes 19.
• the present invention is also applicable to heat exchangers comprising more than two series of tubes 19.
• the heat exchanger 6 is a two-pass heat exchanger comprising a number N of tubes 19 distributed in two series of tubes 19.
• a first series of tubes 19 comprises a number
• a second series of tubes 19 comprises a number N2 of tubes 19.
• the number N of tubes 19 of the heat exchanger 6 is equal to the sum of the number N1 of tubes 19 of the first series of tubes 19 and the number N2 of tubes 19 of the second series of tubes 19.
• the first series of tubes 19 is between a first manifold 21 and a second manifold 22.
• the first series of tubes 19 is between a first compartment 20 of the first manifold 21 and the second manifold 22.
• the second series of tubes 19 is between the second manifold 22 and a third manifold 23.
• the third manifold is formed by a second compartment 23 of the first manifold 21.
• the tubes 19 are identical to each other and have a section A equal to each other of the tubes 19.
• the passage section of the refrigerating fluid FR at the inlet of the external heat exchanger 6 is proportional to the number N1 of tubes 19 of the first series.
• the passage section of the refrigerating fluid FR at the outlet of the external heat exchanger 6 is directly proportional to the number N 2 of tubes 19 of the second series.
• the first collector 21 and the second collector 22 are formed at respective opposite ends of the heat exchanger 6.
• the first collector 21 consists of the first compartment 20 and the second compartment 23 which are arranged in such a manner tight relative to each other.
• the first compartment 20 is juxtaposed with the second compartment 23.
• the first compartment 20 is provided with the first port 15 while the second compartment 23 is provided with the second port 16.
• An insert 24 is interposed between two adjacent tubes 19 to facilitate a heat exchange between the refrigerant FR and the outside air flow 7.
• the tubes 19 are arranged parallel to each other, the N1 tubes 19 of the first series being traversed by the refrigerant fluid FR in a first direction S1 while the N2 tubes 19 of the second series are traversed by the refrigerant in a second direction S2 opposite the first direction S1.
• the N2 tubes 19 of the second series can be traversed by the refrigerant, alternately and / or successively, in a second direction S2, opposite the first direction S1, for a part of the N2 tubes 19 of the second series, and in the first direction S1 for the other part of the N2 tubes 19 of the second series.
• the first orifice 15 of the external heat exchanger 6 constitutes an inlet for the refrigerating fluid FR inside the external heat exchanger 6 and the second orifice 16 for the exchanger 6 is an outlet orifice of the refrigerating fluid FR out of the heat exchanger 6.
• the first orifice 15 of the external heat exchanger 6 constitutes an outlet orifice of the refrigerant fluid FR out of the external heat exchanger 6 and the second orifice 16 of the external heat exchanger 6 constitutes an inlet for the refrigerating fluid FR inside the heat exchanger 6.
• the external heat exchanger 6 according to FIG. 6 is adapted to be integrated in the air conditioning loop 3 according to the illustrated operating mode. in FIG. 4.
• the thermal performance of such a heat exchanger 6 is optimized from the characteristic of the heat exchanger 6 which resides in a ratio N1 / N of between 10% and 50%.
• N1 / N of between 10% and 50%.
• less than half of the N tubes of the heat exchanger 6 is between the first compartment 20 and the second collector 22.
• the heat exchanger 6 verifies the Inequation N1 • N2.
• Such a distribution of the circulation of the refrigerant fluid FR inside the heat exchanger 6 provides optimum performance for optimized operation in "cooling mode” and “heating mode” but also between two opposite configurations of fluid circulation FR refrigerant inside the heat exchanger 6 respectively illustrated in Figures 5 and 6.
• the designers of such a heat exchanger 6 are able to offer a single heat exchanger 6 adapted to operate optimally on a relatively arbitrary air conditioning loop 3 within which circulates a refrigerant fluid FR, indifferently constituted by a hydrofluorocarbon, in particular the fluid known under the name R134a, or a compound based on hydrofluoroolefin, especially the fluid known under the name HFO1234yf.
• a hydrofluorocarbon in particular the fluid known under the name R134a
• a compound based on hydrofluoroolefin especially the fluid known under the name HFO1234yf.
• the refrigerant fluid FR is R134a and the external heat exchanger 6 has a front surface taken perpendicularly to the direction of flow of the outside air 7, that is to say, parallel to the planes of Figures 5 and 6.
• the front surface varies from 20 dm 2 to 31.8 dm 2 .
• FIGS. 7 and 8 show the evolution of the exchanged power P in "cooling mode" between the refrigerating fluid FR and the outside air flow 7 as a function of the ratio N1 / N for flow velocities of the air flow outside 7 through the heat exchanger 6 respectively of 1, 5 m / s, 2 m / s and 3 m / s.
• FIG. 7 shows the evolution of the exchanged power P of the heat exchanger 6 having the front surface equal to 31.8 dm 2 while FIG. 8 shows the evolution of the exchanged power P of the heat exchanger 6 having the frontal area equal to 20 dm 2 .
• the power exchanged P is maximum when the ratio N1 / N is the highest possible.
• FIGS. 7 and 8 show two examples of evolution of the exchanged power P of the heat exchanger 6 for two specific values of the front surface
• the present invention is not limited to these values and also applies heat exchangers 6 having other frontal surface value.
• FIGS. 9 and 10 show the evolution of the exchanged power P in "heating mode" between the refrigerant fluid FR and the external air flow 7 represent the N1 / N ratio for the temperatures of the outside air flow 7 upstream of the external heat exchanger 6 at 0 ° C., at -5 ° C. and at -10 9 C. respectively.
• FIG. 9 shows the evolution of the exchanged power P of the heat exchanger 6 having the front surface equal to 31.8 dm 2 while FIG. 10 shows the evolution of the exchanged power P of the heat exchanger 6 having the frontal area equal to 20 dm 2 .
• the power exchanged P is maximum when the ratio N1 / N is the lowest possible.
• FIGS. 7 to 10 show two examples of evolution of the exchanged power P of the heat exchanger 6 for two specific values of the frontal surface, the present invention is not limited to these values and also applies heat exchangers 6 having other frontal surface value. It is then possible to determine a ratio R proportional to the product of the powers exchanged P according to each of the two modes envisaged. The evolution of the ratio R is represented in FIG.
• the optimized ratio R that is to say the ratio R the largest, is for a ratio N1 / N between 30% and 50%. More particularly, the ratio R is optimized for an N1 / N ratio of between 35% and 45%, preferably of the order of 40%.
• FIGS. 13 to 15 are graphical representations of the evolution of a power exchanged between a second type of refrigerant circulating inside the heat exchanger shown in FIGS. 5 and 6 and an air outside through the heat exchanger according to various arrangements of the heat exchanger.
• the refrigerant fluid FR is HFO1234yf and the heat exchanger 6 has a front surface taken perpendicularly to the flow direction of the outside air flow 7 of the order of 31.8 dm 2 .
• FIG. 13 represents the evolution of the power exchanged P in "cooling mode" between the refrigerating fluid FR and the outside air flow 7 as a function of the N1 / N for the flow rates of the outside air 7 through the heat exchanger 6 respectively of 1, 5 m / s, 2 m / s and 3 m / s.
• the exchanged power P is maximum when the ratio N1 / N is the highest possible.
• FIG. 14 represents the evolution of the exchanged power P in "heating mode" between the refrigerating fluid FR and the outside air flow 7 as a function of the N1 / N for the temperatures of the outside air flow 7 at the inlet of the external heat exchanger 6 at 0 ° C, -5 ° C and -10 ° C, respectively.
• the power exchanged P is maximum when the ratio N1 / N is the lowest possible. It is then possible to determine a ratio R proportional to the product of the powers exchanged P according to each of the two modes envisaged.
• the evolution of the ratio R is shown in FIG. 14.
• the optimized ratio R that is to say the largest ratio R, is found for a ratio N1 / N of between 35% and 50%. More particularly, the ratio R is optimized for an N1 / N ratio of between 40% and 50%, preferably of the order of 45%.
• the optimized ratio N1 / N is between 15% and 35%. More particularly, the ratio R is optimized for a ratio N1 / N of between 15% and 25%, preferably of the order of 20%.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Power Engineering (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Computer Hardware Design (AREA)
• General Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Chemical & Material Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Thermal Sciences (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
• Air-Conditioning For Vehicles (AREA)

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• 2009
  • 2009-08-12 FR FR0903932A patent/FR2949149A1/fr active Pending
• 2010
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  • 2010-07-27 WO PCT/EP2010/060903 patent/WO2011018332A1/fr active Application Filing
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