Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
  • F25D21/00—Defrosting; Preventing frosting; Removing condensed or defrost water
  • F25D21/06—Removing frost
  • F25D21/08—Removing frost by electric heating
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B39/00—Evaporators; Condensers
  • F25B39/02—Evaporators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F19/00—Preventing the formation of deposits or corrosion, e.g. by using filters or scrapers
  • F28F19/006—Preventing deposits of ice
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B3/00—Ohmic-resistance heating
  • H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
  • H05B3/22—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible
  • H05B3/24—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor being self-supporting
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B3/00—Ohmic-resistance heating
  • H05B3/40—Heating elements having the shape of rods or tubes
  • H05B3/42—Heating elements having the shape of rods or tubes non-flexible
  • H05B3/44—Heating elements having the shape of rods or tubes non-flexible heating conductor arranged within rods or tubes of insulating material
• • 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
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F27/00—Control arrangements or safety devices specially adapted for heat-exchange or heat-transfer apparatus
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
  • H05B2203/02—Heaters using heating elements having a positive temperature coefficient
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
  • H05B2203/022—Heaters specially adapted for heating gaseous material
  • H05B2203/023—Heaters of the type used for electrically heating the air blown in a vehicle compartment by the vehicle heating system

Definitions

• Heat exchanger and thermal conditioning device for a motor vehicle comprising such an exchanger
• the present invention relates to a heat exchanger for a thermal conditioning device, in particular for the passenger compartment of a motor vehicle.
• the invention finds its application more particularly in the context of electric or hybrid motor vehicles.
• a conventional air conditioning loop which is capable of operating as a heat pump to heat the air of the passenger compartment from the calories extracted from the vehicle. outside air.
• a loop comprises a heat exchanger at the front of the vehicle, a heat exchanger located in the passenger compartment, the circulation of the fluid in the loop being activated by a compressor.
• the front heat exchanger operates as an evaporator and the passenger compartment heat exchanger as a condenser; in the cooling mode, the functions of the exchangers are reversed.
• the object of the invention is to overcome these disadvantages by providing a solution avoiding any stoppage of operation of the heat pump and making it possible to minimize the modifications made to the air conditioning device as to the front heat exchanger, thus also minimizing the cost system design.
• the subject of the invention is a heat exchanger adapted to operate as an evaporator in a thermal conditioning device traversed by a refrigerant fluid, the exchanger comprising at least one bundle in which the cooling fluid circulates, the exchanger comprising at least one heating element disposed in the vicinity of the beam and capable of heating the beam.
• the beam provides a heat exchange between the fluid and an incident air flow
• the heating element is used to heat the tubes of the evaporator and so defrost them.
• the heating element comprises at least one electrical resistance
• the electrical resistance is a thermistor with a positive temperature coefficient
• the heating element comprises at least a plurality of resistors connected in parallel between two electrical connections, forming a bar,
• the beam comprises tubes in which the coolant circulates
• the beam comprises fins arranged between the tubes, in thermal contact with the latter,
• At least one of the bars is carried by at least one of the fins, said exchanger comprises a plurality of bars carried by the fins,
• the strips are arranged in the bundle so as to ensure a substantially uniform heating of the bundle
• the strips extend substantially along a width of the bundle along said tubes, the strips are distributed between two front halves of said bundle, in alignment with each other and / or in staggered rows,
• said strips occupy a front surface of less than 5%, or even 1%, of a frontal surface of the beam.
• the invention also relates to a thermal conditioning device comprising a heat exchanger as described above, capable of operating as an evaporator.
• said device comprises means for controlling the heating element, ensuring the commissioning of the heating element.
• FIG. 6 an exemplary embodiment of PTC resistors mounted in strips
• FIG. 1 represents a schematic diagram of a thermal conditioning device, in particular intended for a passenger compartment of a motor vehicle, using the exchanger according to the invention.
• this device will be described in the context of its application to a motor vehicle.
• the conditioning device mainly comprises a first heat exchanger 1, a second heat exchanger 7, a compressor 10 and a pressure reducer 4. These various elements are connected in a loop by pipes 5 to be traversed by a refrigerant fluid circulating in the pipes 5 .
• the first exchanger 1 is disposed at the front of the vehicle, generally under the hood on the front of the vehicle, and is traversed by the refrigerant fluid.
• the exchanger 1 is intended to maximize a heat exchange between the refrigerant and a flow of outside air 3 from the front of the vehicle, through its calender.
• the device may comprise a fan 2, for example disengageable, operated when the air flow 3 becomes insufficient.
• the second exchanger 7 is disposed in the passenger compartment of the vehicle, generally in a housing 6 called HVAC (for "Heating, Ventilation and Air Conditioning” or heating, ventilation and air conditioning in English), and is also traversed by the refrigerant. It is intended to maximize the heat exchange between the refrigerant and the air of the passenger compartment, which is shown entering the HVAC 6 by an arrow 8 and emerging by an arrow 9.
• HVAC Heating, Ventilation and Air Conditioning
• the preceding elements form a loop adapted to operate in conventional air conditioning loop: in this case, the fluid refrigerant travels the loop in the direction of the arrows 12; the passenger compartment exchanger 7 then operates as an evaporator, causing the evaporation of the refrigerant which subtracts calories from the air in the passenger compartment, thus cooling the latter.
• the refrigerant fluid in the gaseous state is then compressed in a compressor 10 and then transmitted to the exchanger before 1.
• the latter then operates as a condenser, causing the condensation of the fluid which gives calories to the outside air, before returning to the evaporator 7 via a pressure reducer 4.
• the loop described above is also adapted for operation in a heat pump, operation in which the functions of the exchangers 1 and 7 are reversed, and the direction of travel of the loop (arrows 1 1): the exchanger before 1 operates in an evaporator to take calories from the outside air, calories that the fluid returns to the air of the passenger compartment through the exchanger 7 which then operates as a condenser. More specifically, the refrigerant fluid brought to the gaseous state by the front exchanger 1 is compressed by the compressor 10 before being condensed in the exchanger 7, then again expanded to return to the exchanger 1.
• FIG. 1 is a schematic diagram: in general, in this kind of loop capable of having two distinct modes of operation, two different circuits are provided, the switching between the two modes being carried out by passing through one tubing circuit to the other by means of controlled valves (not shown).
• FIG. 2 represents a partial front view of an embodiment of the exchanger according to the invention.
• the exchanger 1 comprises a set of tubes 20, substantially parallel to each other and in which circulates the coolant.
• the tubes 20 are for example substantially parallel to each other and mounted in parallel between two fluid collectors to which they are connected, only the right collector, referenced 21, being visible in FIG. 2.
• the visible face in FIG. 2 is the front face, disposed on the side of the air inlet 3 (FIG. 1) and situated in a plane marked xO.sub.z of an orthonormal reference Oxyz.
• the tubes 20 are, for example, flattened tubes along the xOy plane and extend in the Ox direction.
• the collectors extend along the Oz axis.
• the tubes 20 are each formed by two plates shaped to be joined together sealingly, to define an interior space where the coolant can circulate.
• fins 22 also called spacers, each consisting for example of a thin strip, made of a good thermal conductive material and formed accordion.
• the fins 22 are in thermal contact with the adjacent tubes 20 and their function is to increase the heat exchange between the outside air, propagating along the axis Oy, and the fluid flowing in the tubes 20.
• the exchanger 1 further comprises at least one heating element 23 disposed in the vicinity of the beam and intended to heat the beam to melt the frost that can cover this beam.
• the heating element 23 is formed by a set of electrical resistors, preferably thermistors with a positive temperature coefficient, or CTP, ie thermistors whose resistance increases with temperature.
• Figure 6 shows, seen in partial section in the plane xOz, an embodiment of the heating element 23 by a PTC strip.
• FIG. 6 is therefore a set of PTCs 60, for example in the form of blocks, arranged side by side and electrically connected, for example in parallel, by conducting strips 61 and 62 arranged on either side of the terminals. 60.
• the assembly forms a bar, preferably covered with a material 63 electrically insulating.
• the PTC strip 23 is disposed on the beam 26 itself. More specifically, it is carried by the fins 22 as illustrated in FIGS. 3, 4 and 5.
• FIG. 3 represents a schematic view, in the xOz plane, of a fin 22 in which cuts have been made such that they can receive the CTP bar 23.
• Figure 4 is the same diagram as that of Figure 3, but with the PTC bar 23 disposed in the fins.
• FIG. 5 is a partial sectional view in the yOz plane of the beam 26 of FIG. 2, on which there are shown two tubes 20 enclosing a portion of a fin 22.
• the fin 22 has the cutout 30 on that of its sides which is situated on the side of the incident external air 3.
• the bar 23 is disposed in the cutout 30.
• the fin 22 has a second cutout 31 on the opposite side to the preceding one, the cutout 31 receiving a second CTP bar 27.
• This insertion mode of the PTC strip 23 in the fins 22 has the advantage of being easily adaptable to existing exchanger models, without requiring a review of the design of the exchanger.
• FIG. 2 also shows control means 25 of the PTC strip 23, electrically connected to connections 24 of the strip 23, connections to which are connected for example the conductive strips 61 and 62 of FIG.
• the control means 25 ensure the commissioning of the CTP 23 when it is necessary to defrost the beam 26. For this purpose, they receive on an input 28 or the parameters indicating that icing occurs.
• the preceding parameters may be those (or derived from those) that trigger the operation of the fan 2 ( Figure 1) when it is controlled. It is possible, for example, to consider as parameters the propulsion engine temperature, the air conditioning requirements displayed, etc. It may also be the operating parameters of the loop of FIG. 1, in particular those which allow the passage of the mode. air conditioning in heat pump mode. They can also be reduced to means for measuring the air temperature in the vicinity of the exchanger 1.
• FIGS 7, 8 and 9 are diagrams illustrating different possible locations of PTC strips in the beam of the exchanger.
• the lines can be distributed in the following way: the first line (bars 71 and 72) at L / 6 of the upper edge, the second line (bars 73 and 74) to L / 3 of the previous line, and the third line (bars 75 and 76) to L / 3 of the previous line, and thus to L / 6 of the lower edge.
• each line is formed by a single strip, respectively marked in the previous order, 81, 82 and 83.
• FIG. 9 A third variant, allowing an even greater uniformization of the heating, is illustrated in FIG. 9: 6 CTP strips 91 - 96 are arranged no more in facing relation to form three lines as in FIG. 7, but in staggered rows. , or staircase.
• the section in the plane xOz of the PTC array (s) 23 will advantageously be limited to about 5% of the total area of the beam 26, and preferably less than 1% of this area. total surface.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Air-Conditioning For Vehicles (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=53269633

Family Applications (1)

Country Status (4)

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Family Cites Families (12)

• 2015
  • 2015-01-21 FR FR1550464A patent/FR3031803B1/fr active Active
• 2016
  • 2016-01-19 EP EP16701019.8A patent/EP3247957A1/de not_active Withdrawn
  • 2016-01-19 JP JP2017538440A patent/JP2018503794A/ja active Pending
  • 2016-01-19 WO PCT/EP2016/051039 patent/WO2016116462A1/fr active Application Filing

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