WO2002090848A1

WO2002090848A1 - Cooling generator for vehicle air conditioner installation

Info

Publication number: WO2002090848A1
Application number: PCT/IB2002/001481
Authority: WO
Inventors: René Vincent GRANDI
Original assignee: Italinnova S.A.S. Di Grandi Rene Vincent
Priority date: 2001-05-07
Filing date: 2002-05-03
Publication date: 2002-11-14
Also published as: FR2824388A1

Abstract

The invention concerns a generator wherein the refrigerating installation circuit (14a, 14b) towards the exchanger (15) arranged in the insulating housing (21) and on its return path, passes through (19) the reservoir (19) containing the eutectic liquid (20) and comprises therein a branch pipe (15a) which is fed under the control of an electric valve (38) controlled by adjusting means (29), while the latter are connected through control electrical circuits to the means (17, 18) generating the air stream and to the pump (27) of the secondary circuit, and comprise a programme triggering, when the vehicle is stopped and at least sequentially, the supply of the pump (27) of the accumulation circuit and the means (17, 18) generating the air stream, and when the vehicle is moving and at the start of the air conditioning process, the opening by the electric valve (38) of the branched refrigerating circuit (15a) and the supply of the secondary circuit pump, only after the temperature of passenger compartment has reached a comfort value.

Description

Cold generator for vehicle air conditioning system.

The invention relates to a cold generator for vehicle air conditioning installation.

In its international application WO 01 63188 relating to a cold generator for storage and air conditioning installation, the applicant combines, with the liquid / air exchanger of a refrigeration installation arranged in an oriented air flow conditioning the vehicle, the exchanger of a cold accumulator forming part of a complementary circuit containing a frigory accumulator material, such as an aqueous mixture of sodium chloride, glycol, alcohol or equivalent, so that, by its arrangement downstream of evaporator, this accumulator can take care of the frigories of air coming from passing through said evaporator to restore them to a standstill using the means generating the air flow. The exchanger of the complementary exchange circuit is either mixed with that of the refrigeration circuit, for example in the same structure with evaporator fins, or disposed in one or more independent accumulator elements of the evaporator, but arranged downstream of it.

The multiplication of accumulators has been envisaged in order to increase the quantity of refrigerant storing fluid, in order to bring it to a value sufficient for it to be able to restore cold for several hours when the vehicle is stopped. If this solution is technically feasible, it requires the manufacture of special accumulators, therefore more expensive than standard evaporators, and does not allow the structures of standard evaporators to be used by adapting them because, in these, the capacity of the coil d exchange is of the order of 1.5 liters and therefore involves considering batteries of 6 to 10 cells to obtain a sufficient storage volume of the accumulator fluid.

The present invention aims to remedy this by increasing the amount of refrigerant accumulator fluid without having to increase the number of accumulators, so that a vehicle air conditioning installation can, when the vehicle is stopped and refrigeration system, maintain the temperature of the passenger compartment of a vehicle for several hours, and this with low energy consumption.

US Pat. No. 5,735,133 discloses a vehicle air conditioning installation comprising, in the oriented air flow going to the passenger compartment and, in addition to or in place of the evaporator or liquid / air exchanger of a refrigeration installation , a second liquid / air exchanger forming part of a circuit containing a heat transfer fluid and comprising an insulating reserve with means for accumulating frigories, distinct from the coolant, a circulation pump and a liquid / liquid exchanger supplied by the refrigeration installation. Intended to accelerate the cooling of the passenger compartment when starting the vehicle, in particular in urban traffic, this installation provides no solution to cooling the passenger compartment of the vehicle when stationary.

German patent application DE 199 12 139 relates to a vehicle air conditioning installation comprising a first refrigeration circuit, which can be supplied when the vehicle is stopped or permanently installed, an isolated reserve containing an aqueous eutectic mixture and in which are installed d on the one hand, the liquid / liquid exchanger of the refrigeration installation, and, on the other hand, a liquid / liquid exchanger of a second exchange circuit containing a heat transfer fluid, such as glycol water, and comprising a liquid / air exchanger arranged in the oriented air flow for air conditioning the passenger compartment. Designed to optimize and manage the consumption of frigories in the reserve, according to the cooling needs of the passenger compartment, this installation includes numerous sensors of the temperature of the heat transfer fluid in various locations, of the passenger compartment and of the outside air. , but also a reserve pressure sensor. When the reserve is charged, in cold or in heat, the installation can ensure a punctual pre-air conditioning, but the document does not describe how and with what means it could provide a solution to maintaining a comfortable temperature in the passenger compartment , when the vehicle is stopped in the sun for several hours and after having consumed all the frigories of its reserve to ensure air conditioning during the movement of the vehicle.

Another object of the invention is to provide means making it possible to rapidly accumulate frigories in the accumulator and its reserve, without this disturbing the air conditioning when the vehicle is started and increasing the time necessary to reach a comfort temperature, and without causing excessive energy consumption and a decrease in thermal efficiency by increasing exchanges. The device according to the invention comprises the means of the state of the art described in the preamble of claim 1.

According to the invention, the circuit of the refrigeration installation, going to the exchanger of this installation arranged in the insulating casing and returning, crosses the reserve containing the eutectic liquid and comprises in it a bypass whose supply is under the control of a solenoid valve controlled by the regulating means, while the latter are connected by circuits electrical controls to the means generating the air flow, to the pump of the secondary circuit and to the control means of the compressor of the refrigerating installation, and include a triggering programming, vehicle stopped and at least sequentially, l supply of the pump of the accumulation circuit and of the means generating the air flow, and, when the vehicle is moving and at the start of air conditioning, the opening by the solenoid valve of the refrigerant branch circuit and the supply to the pump of the secondary circuit, only after the temperature in the passenger compartment has reached a comfort value.

With this arrangement, the quantity of fluid stored does not depend on the number of accumulator elements, but only on the capacity of the reserve which, due to its independence with the exchanger-accumulator, can be moved away from the latter and arranged in a less congested area of the vehicle, and therefore may have a volume satisfying the needs.

In addition, the eutectic fluid contained in the reserve is cooled both by the liquid / air exchanger of the secondary circuit and by the derived refrigerant circuit, which reduces the charging time and the energy consumption taken from the engine of the vehicle.

However, in order not to absorb frigories from the start of the air conditioning of the passenger compartment, by risking extending the duration of obtaining the chosen air conditioning temperature, the programming takes into account the temperature in this passenger compartment and only allows it to operate. the refrigeration circuit exchanger, as long as this temperature has not reached a determined threshold, corresponding to a temperature providing comfort but higher than the air conditioning temperature. As soon as this threshold is reached, the solenoid valve is energized to connect the bypass to the refrigeration circuit. Simultaneously, the pump of the secondary circuit, which until then was not supplied to isolate the exchanger-accumulator, is supplied to circulate the eutectic fluid in the secondary circuit. It follows that the frigories accumulated by the heat exchanger-accumulator are transferred to the reserve to add to that provided by the bypass of the refrigeration circuit.

When the temperature in the reserve reaches a value defined by the characteristics of the eutectic fluid, the programming controls the solenoid valve so that it closes the bypass and stops the supply of the pump. The refrigerant energy thus accumulated in the reserve can be used either when the vehicle is stopped or as a replacement for the air conditioning provided by the refrigeration circuit exchanger, for example when returning the vehicle to a garage or to temporarily increase the power of the vehicle.

When the vehicle is stopped with a cold reserve loaded and the engine stopped, the temperature rise in the passenger compartment triggers the programming which feeds, at least sequentially, the circulation pump of the secondary circuit and the means generating the air flow oriented in the insulating casing, to bring frigories into the passenger compartment while avoiding too great a rise in temperature.

For a use of the frigories of the reserve in replacement of those produced by the refrigeration unit and in an embodiment of the device, the command and control means are electrically connected on the one hand, to the power supply control of the compressor of the refrigeration unit and, on the other hand, to a contactor for preferential selection of cooling by the secondary circuit. Advantageously, the reserve is provided with internal partitions distributed in baffles and delimiting a preferential circuit followed by the serpentine of the derived refrigeration circuit, so that the refrigerant accumulator fluid, coming from the exchanger-accumulator by the return duct and traveling in this reserve, also takes care of the refrigeration of the refrigeration circuit. The invention will be better understood with the aid of the description which follows with reference to the appended schematic drawing representing, by way of example, several embodiments of the cold generator according to the invention.

FIG. 1 is a schematic view of a first embodiment of the air conditioning installation implementing the cold generator according to the invention,

FIG. 2 is a perspective view illustrating the installation of the installation in a motor vehicle,

Figure 3 is a partial perspective view of an embodiment of a fin structure with double exchanger. Figure 4 is a partial cross-sectional view of an embodiment of the reserve when it is equipped with a preferred internal circuit.

Figure 5 is a partial perspective view of the passenger compartment of a vehicle equipped with an alternative embodiment of this installation.

In known manner, this refrigeration installation for the air conditioning of a vehicle comprises, as shown in FIG. 1, a compressor 1 driven, with the interposition of an electromagnetic clutch 2, by a transmission by pulley and belt, not shown, taking movement from the vehicle engine. From the compressor 1 there is a line 5 going to a condenser 6 and ends up a line 7 coming from an evaporator 8. The condenser 6 is connected by a line 9 to a tank 10, itself connected by a line 12 to a pressure reducer 13 The regulator communicates by a conduit 14a with the tubular coil 15 of evaporator 8, a coil of which another end is connected, by a conduit 14b, to the conduit 7. This coil 15 constitutes the liquid / air exchanger of the refrigeration unit and is linked to the fins of a fin structure 11.

In the embodiment shown, the fin structure 11 also contains the coil 16 of the exchanger-accumulator of a secondary exchange circuit. It is arranged in an insulating casing 21 with means generating an air flow oriented through the coils 15 and 16, such as a double turbine 17 driven by an electric motor 18.

The mouths, not shown, of inlet and outlet of the casing are equipped with disinfectant and bactericidal filters, removable and interchangeable, and, optionally, automatic shutters opening when the turbine 17 is active.

The coil 16 of the exchanger-accumulator is connected to a reserve 19 filled with a liquid 20 capable of accumulating frigories such as aqueous mixture of sodium chloride, glycol water, ... The reserve 19 is insulated by a coating of thermal insulation 22, comprises a filling orifice 23 with plug 24 and is connected to the coil 16 by an inlet duct 25 and by a return duct 26, both coated with a thermal insulator. On the conduit 25, an electric pump 27 is arranged, the supply circuit 28 of which is under the control of a control and regulation unit 29, itself connected by a circuit 30 to a temperature sensor 32 arranged in the cockpit. The box 29 also controls the supply circuit 33 of the electric motor 18 driving the turbine 17.

The conduits 14a and 14b of the refrigeration circuit pass through the reserve 19 and, in the latter, are connected by a serpentine coil 15a. At least the junction zone between the branch 15a and the conduit 14a is equipped with a solenoid valve 38, connected by a control circuit 39 to the housing 29.

This box is also connected by a circuit 36 to a sensor 35 of the temperature of the fluid in the reserve, by a circuit 37 to the electric clutch of the compressor 1, and by a circuit 31 to a contactor 41 for preferential selection of air conditioning by the secondary accumulation circuit. When the refrigeration installation is in operation and the reserve 19 is loaded, the cold generated by the coil 15 of the evaporator 8, forming a liquid / air exchanger, is transmitted by the oriented air flow, generated by the turbine 17, in the passenger compartment of the vehicle and, simultaneously, passes over the coil 16 of the heat exchanger-accumulator which, then forming an air / liquid exchanger, is responsible for part of the frigories transported by this air flow. By the pump 27, the eutectic fluid 20 contained in this coil 16 is permanently exchanged with that contained in the reserve 19. In the latter the solenoid valve 38 is in a position allowing the supply of the bypass 15a by the fluid refrigerant so that the fluid from the heat exchanger-accumulator 16 is also charged in cold by circulating against the coil of this bypass.

To accelerate this exchange and reduce the cold loading time of the reserve 19 and the secondary circuit, and as shown in the embodiment of Figure 4, the reserve 19b is provided with internal partitions 46 which, by their distribution in baffles , delimit a preferential circuit for the eutectic fluid 20 coming, via the conduit 26, from the exchanger-accumulator 16. Thus, to the frigories taken from the air flow are added the frigories taken from the refrigerating circuit, so that, quickly, the content of the reserve 19 is brought to the temperature at which its load is maximum. At the start of the operation of the air conditioning of the vehicle, programming, forming part of the means 29 for regulation, reacts to the information from the sensor 32 of the temperature in the passenger compartment. If the value of this temperature is much higher than a reference comfort value, for example is 42 ° C for 23 ° C, the programming controls the solenoid valve 38 so that it closes the bypass 15a and that it controls l pump stop 27. Thus, as long as the reference temperature is not reached, the energy of the refrigeration unit is only used for air conditioning. As soon as the reference temperature is reached and while the refrigeration unit must still supply cold for the passenger compartment to reach the air conditioning temperature chosen by the user, the programming acts on the solenoid valve 38 and on the pump 27 to start the cold loading of reserve 19 as described above.

When the load is maximum, that is to say when the reserve is at its lowest temperature that can be reached, the sensor 35 informs the programming of the regulation means 29 which, as required: - can stop the supply of the bypass 15a and of the pump 27, to ensure air conditioning only by the refrigeration unit, - Either stop only the supply of the bypass 15a, at the same time as it controls the stopping of the compressor 1, for example by acting on its clutch, and this to ensure the air conditioning only with the reserve 19 accumulated frigories. In the latter case, the pump 27 continues to circulate the refrigerant accumulator fluid, so that this fluid, arriving in the exchanger-accumulator 16, then operating as a liquid / air exchanger, passes into the restitution phase by yielding part of its frigories to the air flow generated by the turbine 17 which also continues to operate. As long as the accumulation of frigories in the reserve 19 is sufficient, the air conditioning is ensured by restitution of these frigories. On the other hand, as soon as the temperature in the reserve 19 reaches a lower threshold value, the refrigeration installation is put back into operation, so as to satisfy the needs of the air conditioning and, simultaneously, ensure the recharging of the reserve 19. The contactor selection 41 can be operated by the user to stop the compressor 1 and the supply to the refrigeration circuit and favor air conditioning by the secondary circuit:

- either to consume the frigories accumulated in the reserve, for example before the vehicle is stopped overnight, - or to increase the power of the vehicle engine by eliminating the energy requirement of the refrigeration unit.

When the vehicle is stationary, in which case the refrigeration system is also stopped, the cabin temperature is maintained only by the accumulation of frigories stored in reserve 19 according to demand, and by putting in motion the pump 27 and the electric motor 18 driving the turbine 17.

The housing 29 is, for this purpose, equipped with a sequential control, causing the supply of the pump 27 and of the motor 18 for a few minutes, for example 2 minutes, every 15 minutes. Under these conditions and with an accumulator fluid 20 providing the maximum accumulation at -5 ° C., such as an aqueous mixture of sodium chloride, glycol, alcohol, antifreeze, a reserve 19 containing between 10 and 15 liters of this fluid, appears sufficient to maintain the temperature of the passenger compartment of a stationary vehicle for 4 hours.

FIG. 2 shows that, thanks to the independence between, on the one hand, the fin structure 11 containing the two exchangers 15 and 16 and, on the other hand, the reserve 19, these two subassemblies can be arranged side by side, but also by being spaced apart, and for example in the front trunk of the vehicle.

In the embodiment shown in FIG. 3, the coil 15 of the refrigeration circuit is arranged with the coil 16 for circulation of the accumulating fluid in the same exchange structure with parallel fins 11, but the same results can be obtained, at the dimensions, by placing the coil of the heat exchanger-accumulator 16 in a fin structure, distinct from that containing the coil of the heat exchanger 15 of the refrigeration circuit, and disposed downstream of this exchanger, relative to the direction of circulation of the flow generated by the turbine 17.

FIG. 5 shows a variant of the installation of FIG. 1 in which the secondary circuit with eutectic accumulator fluid 20 is provided with a bypass 44 in the form of a coil which, supplied by a circulation pump 48, is arranged in an insulated enclosure 42 constituting a refrigerated bar. With a cold storage fluid brought to -5 ° C, this refrigerator can make ice cubes in a compartment 43 of the enclosure 42. The latter can, as shown, be located in or under the dashboard, but also between two seats, in the back of a seat, or in the luggage compartment of the vehicle. Of course, the pump 48 is under the control of a thermostat placed in the enclosure 42.

In an alternative embodiment, the branch 15a of the refrigeration circuit comprises a second solenoid valve 38a, multi-way like that 38, is disposed between the branch 15a and its connection with the conduit 14b for return of the fluid coming from the coil 15. This solenoid valve 38a operates in same time as that 38 to isolate the bypass without opposing the return of the refrigerant to the compressor.

Claims

1. Cold generator for vehicle air conditioning system, comprising:

electrical means (17, 18) generating an air flow oriented in an insulating casing (21) communicating with the passenger compartment,

- a refrigeration installation (1 to 8) with a circuit of which evaporator (8, 15), constituting liquid / air exchanger, is arranged in the insulating casing (21),

a liquid / air exchanger-accumulator (16) disposed in the insulating casing (21) downstream of the refrigerating exchanger (15), this lo-accumulator exchanger being part of a secondary circuit containing a eutectic fluid (20), able to take care of the frigories carried by the air flow,

- a heat-insulated reserve (19) containing eutectic fluid (20) and connected to the heat exchanger-accumulator (16) by a flow pipe (25) and by a return pipe (26), one of these pipes being equipped with a pump

15 circulation (27),

- and means (29) of regulation and control reacting to temperature sensors (32, 35) arranged in the passenger compartment and in the reserve (19), characterized in that the circuit of the refrigeration installation (14a, 14b), going to the exchanger (15) arranged in the insulating casing (21) and returning, crosses the

20 reserve (19) containing the eutectic liquid (20) and comprises, in the latter, i a bypass (15a) the supply of which is under the control of a solenoid valve (38) controlled by the regulating means (29) , while the latter are connected by electrical control circuits to the means (17, 18) generating the air flow and to the pump (27) of the secondary circuit, and comprise a

25 triggering programming, vehicle stationary and at least sequentially, supply to the pump (27) of the accumulation circuit and means (17, 18) generating the air flow, and, vehicle in motion and at the start of air conditioning, the opening by the solenoid valve (38) of the refrigerant branch circuit (15a) and the supply of the secondary circuit pump, only after the

3 o temperature in the passenger compartment has reached a comfort value.

2. Cold generator according to claim 1, characterized in that, the regulation and control means (29) are electrically connected on the one hand, to the power supply control of the compressor (1) of the refrigeration unit and, d on the other hand, to a contactor (41) for preferential selection of cooling by

35 the secondary circuit.

3. Cold generator according to claim 1, characterized in that the reserve (19b) is provided with internal partitions (46) distributed in baffles and delimiting a preferential circuit followed by the coil (15b) of the derived refrigeration circuit, so that the refrigerant accumulator fluid (20) coming from the exchanger

5 accumulator (16) via the return duct (26) and passing through this reserve also takes care of the frigories of the refrigeration circuit.

4. Cold generator according to claim 1 characterized in that the secondaired "accumulation circuit comprises a bypass (44) disposed in a heat-insulated enclosure (42) forming on-board refrigerator and comprising a compartment or compartment (43) for making ice cubes.

5. Cold generator according to claim 1 characterized in that the fin exchange structure (11), its exchange circuit (s) (15, 16) and its means (17) generating an oriented air flow are arranged in a casing (21) whose air vents, respectively inlet and outlet, are equipped with filters

15 disinfectants and bactericides.