FR2876323A1 - Temperature regulation device for passenger compartment of motor vehicle, has loop including heat exchanger unit with two heat exchangers that are mounted in parallel and have valves mounted in anti-parallel manner to supply heat exchangers - Google Patents

Abstract

The device has a loop (7) in which a coolant circulates along two opposite direction, in heating and cooling modes of a passenger compartment. A heat exchanger unit of the loop has a case including two heat exchangers (15a, 15b) that are mounted in parallel and have valves (CL1, CL2). The valves are mounted in anti-parallel manner to supply the heat exchangers in heating or cooling mode of the passenger compartment. An independent claim is also included for a process of regulating temperature in a passenger compartment of a motor vehicle.

Description

Device and method for regulating the temperature of the passenger compartment of a

motor vehicle

  The present invention relates to a device and a method for the thermal regulation of the passenger compartment of a motor vehicle.

  Devices of this type are known which comprise a refrigerating loop in which circulates a refrigerant, a secondary loop in which circulates a heat transfer fluid, a heat exchanger through which the refrigerant and the coolant pass, and exchange means. thermal traversed by the heat transfer fluid and by a flow of air for heating or cooling the passenger compartment.

  For example, in this type of device, the refrigerant loop can be a reversible loop. The direction of circulation of the refrigerant in the loop thus makes it possible to obtain either a reheating or a cooling of the fluid, the loop then operating either as a refrigerating system generating frigories, or as a heat pump. The coolant, which may be, for example, glycol water can transfer calories or frigories in the passenger compartment of the vehicle through the air flow through the heat exchange means.

  In this regard, reference may be made to French patent application 2,780,490 or European patent application 0 582 479, which describe a system for adjusting the temperature in the passenger compartment of a vehicle comprising a secondary buckle equipped with means heat exchange provided with a fan.

  French patent applications 2 808 740, 2 808 741 and 2 808 742 also disclose a thermal regulation device for the passenger compartment of a motor vehicle comprising an exchanger for the production of cold and an exchanger for the production of heat. , both arranged in the passenger compartment of the vehicle and all the other elements of the system being mounted in the engine compartment. These devices have the disadvantage of being bulky.

  The French patent application 2 808 068 describes a heating and air conditioning device of the passenger compartment of a vehicle which comprises a single exchanger placed in the passenger compartment and can alternatively provide air conditioning or heating. Such a device, if it has the advantage of greater compactness, does not prevent the phenomenon of instantaneous formation of vapor that occurs when the same exchanger, over a short period of time, is used successively to produce cold then to produce hot. In this case indeed, the exchanger having first operated in air conditioning mode is loaded with moisture. When the hot heat transfer fluid circulates in this same exchanger, the moisture vaporizes, causing the instantaneous appearance of steam in the passenger compartment.

  Moreover, in most known thermal regulating devices for motor vehicle passenger compartment, even when the compactness is improved, air conditioning loops, which are the seat of leaks, retain a relatively long length, which generates a leakage of fluid refrigerant to the outside non-negligible.

  In view of the above, the present invention aims to limit refrigerant leakage to the outside by limiting the length of the air conditioning loop and limit over-consumption of the vehicle, while allowing greater comfort in the air. set of the cockpit.

  The subject of the invention is therefore a device for the thermal regulation of the passenger compartment of a motor vehicle comprising a refrigerating loop in which a refrigerant circulates, a secondary loop in which a heat transfer fluid circulates, a heat exchanger through which the fluid passes. refrigerant and the heat transfer fluid, and heat exchange means traversed by the heat transfer fluid and by a flow of air for heating and cooling the passenger compartment of the vehicle.

  The heat transfer fluid in the secondary loop flows in two opposite directions in the heating mode of the passenger compartment, on the one hand, and in the cooling mode of the passenger compartment, on the other hand. In addition, the heat exchange means comprise at least one set of two heat exchangers adapted to be selectively traversed by the coolant, the half-exchangers being connected in parallel and each being equipped with a valve, said valves being mounted in antiparallel so as to feed one or the other half-heat exchanger in heating mode and cooling mode of the passenger compartment.

  It is therefore possible to considerably limit the length of the loops, and in particular of the secondary loop.

  In one embodiment, the valves are integrated in the exchangers According to another characteristic of the invention, the secondary loop constitutes a bypass loop of a thermal control circuit of the drive motor of the vehicle and communicates with the latter by the intermediate of a valve adapted to communicate the secondary loop with the thermal control circuit of the vehicle engine in the cabin heating mode by short-circuiting the heat exchanger and isolating it from said control circuit in communicating with the heat exchanger in the cabin cooling mode.

  In addition, the device is provided with a pump for circulating the heat transfer fluid in the secondary loop in cooling mode of the passenger compartment. This pump can be mounted downstream or upstream of the exchanger, considering the direction of circulation of the fluid in the cooling mode of the passenger compartment. However, when the pump is installed upstream of the exchanger, the device becomes more efficient because the cooled water does not receive the calories due to friction in the pump.

  We can provide a set of two half-exchangers integrated into the dashboard of the vehicle.

  The device according to the invention is particularly adapted to allow to fully accommodate the refrigerating loop in the engine compartment of the vehicle.

  Advantageously, the refrigerant loop is a reversible loop.

  The subject of the invention is also a thermal regulation method for the passenger compartment of a motor vehicle using a refrigerant loop in which a refrigerant circulates, a secondary loop in which a heat transfer fluid circulates, a heat exchanger through which the fluid passes. refrigerant and the heat transfer fluid, and heat exchange means traversed by the coolant and by a flow of air for heating and cooling the passenger compartment, characterized in that it circulates the heat transfer fluid in the secondary loop in two opposite directions in the cabin heating mode, on the one hand, and in the cabin cooling mode, on the other hand, and in that the heat exchange means comprising at least one set of two half-heat exchangers adapted to be selectively traversed by the coolant, mounted in parallel and equipped respectively equipped with two valves my In antiparallel mode, the one or the other half-exchanger is supplied in the heating mode and in the cooling mode of the passenger compartment.

  Other objects, features and advantages of the invention will become apparent on reading the following description, given solely by way of nonlimiting example, and with reference to the appended drawings in which: FIG. 1 is a block diagram illustrating the general architecture of a device according to the invention; - Figure 2 illustrates the operation of the device of Figure 1 in the cooling mode of the passenger compartment; FIG. 3 illustrates an alternative embodiment of the device according to the invention; and FIG. 4 illustrates an alternative embodiment of the device according to the invention. In FIGS. 1 and 2 are diagrammatically represented the main constituent elements of an embodiment of a thermal regulation device according to the invention. In these figures, the engine compartment of the motor vehicle is designated by the letter M while the passenger compartment is designated by the letter H. The long dashed line represents the boundary between the engine compartment and the passenger compartment of the vehicle.

  As seen in the figures, the device according to the invention comprises, in the engine compartment M, a refrigerating loop 1 in which circulates a refrigerant whose circulation is symbolized by a dashed line. The refrigerating loop 1 comprises a heat exchanger 2 constituted by a condenser, an expansion element 3, a second heat exchanger 4 constituted by an evaporator, a compressor 5 and a battery 6. A fan or blower P is capable of a flow of air on the condenser 2.

  The device is also provided with a secondary loop 7 in which circulates a heat transfer fluid and which is coupled to the cooling circuit 8 of the power unit 9 of the motor vehicle. This cooling circuit is provided with a circulation pump 10 which causes the circulation of the coolant through the power unit and then through a radiator 11 via a thermostat 12.

  As can be seen in the figures, the secondary loop 7 constitutes a bypass of the power train cooling circuit 8 to which it is connected via a three-way valve 13.

  This valve 13 is further adapted to allow the communication of the secondary loop 7 with the evaporator 4 via a pump 14.

  The secondary loop 7 is equipped with heat exchange means consisting of several housings 15 arranged in the passenger compartment. In this figure, only one housing 15 has been shown. Of course, the cabin can be provided with several identical housings, arranged in parallel and each providing thermal regulation of a zone Z of the passenger compartment. Each housing 15 comprises two heat exchangers 15a15b connected in parallel and which communicate with the rest of the secondary loop 7 via two lines 16 and 17. One of the exchangers, namely the exchanger designated by the reference 15a , constitutes a cold exchanger, the other exchanger constituting a hot heat exchanger, and are intended to respectively provide cooling and heating of the passenger compartment. A fan 18 is used to cause air circulation through the exchangers 15a and 15b under the control of an air mixing flap V capable of directing the flow of air generated by the fan 18 to the exchangers, or by short-circuiting and directing the air flow through a passage 19, intermediate positions being also provided. In each case, it is therefore possible to regulate the air flow through the exchangers by controlling the operation of the fan, but also the temperature by regulating the water flow imposed by the pump 14 of the secondary loop and by adjusting the position. flap V which allows more or less air to pass through the exchangers.

  The direction of circulation of the coolant in the secondary loop 7 is reversible depending on the operating mode of the device, that is to say either in the heating mode of the passenger compartment (Figure 1), or in cooling mode (Figure 2). ). Valves CL1 and CL2 are provided for short-circuiting one or the other of the exchangers 15a and 15b depending on the operating mode of the device.

  The three-way valve 13 is in fact adapted to put the secondary loop 7 into communication with the circuit 8 for regulating the thermal regulation of the vehicle engine, by isolating from the evaporator 4 and to put this secondary loop 7 in communication with the evaporator 4 by isolating the circuit 8 of thermal control of the engine, respectively in the heating mode of the passenger compartment and cooling mode of the passenger compartment.

  The valves CL1 and CL2 are positioned so as to block the arrival of coolant at the inlet of one or other of the exchangers 15a and 15b, so that one of the exchangers, namely the exchanger 15a , receives only frigories from the evaporator 4 and the hot heat exchanger 15b receives only calories from the engine. In this way, it is avoided that calories vaporize condensates retained in a previously cooled exchanger.

  By way of example, the device can be controlled according to two different modes of operation, illustrated in FIGS. 1 and 2, on which the arrows represent the direction of circulation of the coolant or refrigerant manner.

  Situation 1: cold environment: The 3-way valve 13 is located in the position shown in Figure 1 so as to directly communicate the secondary loop 7 with the circuit 8 of thermal control of the engine. In this case, the hot water from the power train 9 feeds the loop 7. The CL1 valve is closed and the coolant flows through the heat exchanger 15b. The CL2 valve is open. Pump 14 is stopped.

  Situation 2: warm environment: the 3-way valve 13 is positioned in the position visible in FIG. 2 in which the secondary loop 7 is isolated from the thermal control circuit 8 of the motor and flows through the evaporator 4. The pump 14 is activated. The coolant flows in the opposite direction. The CL2 valve is closed under the effect of the pressure in the loop 7 so that the coolant circulates through the cold exchanger 15a. The CL1 valve is open.

  It will be understood that the invention, according to which the heat transfer fluid always circulates in a single heat exchanger while the other is isolated from the remainder of the circuit by the valve with which it is associated, and which uses a secondary loop which constitutes a bypass of the thermal control circuit of the engine avoids any phenomenon of instantaneous appearance of steam in the cabin to the extent that, in heating mode, the hot heat transfer fluid is not in contact with a previously cooled heat exchanger. It also makes it possible to limit fluid leakage to the extent that the installation has an increased compactness. Note however that the invention is not limited to the embodiment described.

  Indeed, in the embodiment described with reference to Figures 1 and 2, the thermal control device is provided with heat exchange means arranged in the form of housings disposed in the passenger compartment.

  As seen in Figure 3, it is also possible to have a housing 20 integrated way to the dashboard of the vehicle. This embodiment makes it possible to improve the performance of the device in a hot environment, in particular for putting it into action and also makes it possible to provide a defogging function. This embodiment also makes it possible to balance the temperature of the passenger compartment in addition to the calories or frigories generated by the housings 19 of zones Z1 and Z2.

  It should be noted that the refrigerating loop can also be reversible, so that the invention is also adapted to an embodiment in which it operates either as a refrigeration system or as a heat pump. In this case, it will be provided to install a four-way valve for connecting the secondary loop and allow a change of direction of circulation of the refrigerant.

  Finally, note that the invention is not limited to the embodiment described above. Indeed, as shown in Figure 4 in which elements identical to Figures 1 to 3 are represented by the same reference numerals, it is possible to provide the control device according to the invention of a reversible refrigerating loop 1. In this embodiment, the secondary loop communicates only with the refrigerating loop 1 via the heat exchanger 4. It is provided with two branches 20A and 20B each equipped with a pump 21A and 21B arranged in antiparallel so that the fluid flows in two opposite directions in the branches 20A and 20B.

  Thus, when the reversible loop 1 constitutes a cold loop, the pump designated by the reference 21A is actuated and the other pump 21 B is stopped. The fluid in the secondary loop then circulates in the exchanger 15a.

  Conversely, when the reversible loop 1 constitutes a hot loop, the pump designated by the reference 21B is actuated and the other pump 21A is stopped. The fluid in the secondary loop then circulates in the exchanger 15b.

Claims (9)

  1. Device for regulating the thermal environment of the passenger compartment of a motor vehicle, comprising a refrigerating loop (1) in which a refrigerant circulates, a secondary loop (7) in which a heat transfer fluid circulates, a heat exchanger (4) traversed by the refrigerant and the coolant, and heat exchange means (15; 19, 20) traversed by the coolant and by a flow of air for heating or cooling the passenger compartment, characterized in that the heat transfer fluid in the secondary loop flows in two opposite directions in heating mode of the passenger compartment, on the one hand, and in the cooling mode of the passenger compartment, on the other hand, and in that the means of heat exchange comprise at least one set of two half-heat exchangers (15a, 15b) adapted to be selectively traversed by the coolant, the half-exchangers being connected in parallel and each being equipped with a clape t (CL1, CL2), said valves being mounted in antiparallel so as to supply one or the other half-heat exchanger in heating mode and cooling mode of the passenger compartment.   2. Device according to claim 1, characterized in that the secondary loop (7) constitutes a bypass loop of a circuit (8) of thermal regulation of the drive motor of the vehicle and communicates with the latter via a valve (13) adapted to communicate the secondary loop with the thermal control circuit of the vehicle engine in the cabin heating mode by short-circuiting the heat exchanger and isolating it from said control circuit by making it communicate with the heat exchanger in the cabin cooling mode.   3. Device according to one of claims 1 and 2, characterized in that the valves are integrated in the exchangers.   4. Device according to any one of claims 1 to 3, characterized in that it comprises a pump (14) provided for circulating the heat transfer fluid in the secondary loop in cooling mode of the passenger compartment.   5. Device according to claim 4, characterized in that the pump (14) is disposed upstream of the heat exchanger, considering the flow direction of the fluid in the cooling mode of the passenger compartment.   6. Device according to any one of claims 1 to 5, characterized in that it comprises a set (20) of two half-exchangers integrated in the dashboard of the vehicle.   7. Device according to any one of claims 1 to 6, characterized in that the cooling loop is fully housed in the engine compartment (M) of the vehicle.   8. Device according to any one of claims 1 to 7, characterized in that the refrigerant loop (1) is a reversible loop.   9. A method of thermal regulation of the passenger compartment of a motor vehicle using a refrigerant loop (1) in which a refrigerant circulates, a secondary loop (7) in which circulates a heat transfer fluid, a heat exchanger (4) crossed by the refrigerant and the heat transfer fluid, and heat exchange means (15; 16, 20) traversed by the coolant and by a flow of air for heating or cooling the passenger compartment of the vehicle, characterized in that that the heat transfer fluid is circulated in the secondary loop in two opposite directions in the heating mode of the passenger compartment, on the one hand, and in the cooling mode of the passenger compartment, on the other hand, and in that the heat exchange means comprising at least one set of two half-heat exchangers (15a, 15b) adapted to be selectively traversed by the coolant fluid, connected in parallel and equipped respectively equipped with two valves (CL 1, CL2) mounted in antiparallel, one feeds the one or the other half-heat exchanger in heating mode and cooling mode of the passenger compartment.