FR3057211A1 - METHOD FOR CONTROLLING A HEATING LOOP, VENTILATION AND / OR AIR CONDITIONING - Google Patents

Abstract

The subject of the invention is a method of regulating a heating loop, an air flow intended for a passenger compartment inside which a refrigerant circulates, said loop comprising at least one compressor and a condenser, the loop being configured to operate in heat pump mode according to a first closed circuit comprising the compressor and the condenser, the loop being configured to circulate the fluid in a second closed circuit, said method comprising a step, called a pumping step, in which the loop is configured so that the refrigerant flowing in the first closed circuit is directed from the first closed circuit in the second closed circuit.

Description

TECHNICAL AREA

The invention relates to a method for regulating a heating, ventilation and / or air conditioning loop of an air flow intended for a passenger compartment of a motor vehicle.

STATE OF THE ART

A vehicle, in particular an electric or hybrid vehicle, is commonly equipped with a heating, ventilation and / or air conditioning system for modifying the aerothermal parameters of an air flow entering inside a passenger compartment of the vehicle. To this end, the installation includes a heating, ventilation and / or air conditioning device delimited by a box and capable of controlling the air flow prior to its introduction inside the passenger compartment, according to the requirements of the 'user. To modify the temperature of the air flow, prior to its introduction into the passenger compartment, the installation notably includes a heating, ventilation and / or air conditioning loop inside which a refrigerant circulates.

Such a loop can conventionally operate according to "an air conditioning mode", "a dehumidification mode" or even "a heat pump mode".

When the loop operates in “heat pump mode” also called “heating mode”, it can be seen that when the air temperature outside the vehicle is low, for example below -10 ° C, the power heating available is not sufficient to meet the needs of the user.

For example, using R134a or R1234yf refrigerant and when the outside air temperature is -18 ° C, the available heating power is around 2700 W while the heating power required to satisfy user requirements is estimated at 5000 W.

0 The object of the present invention is to provide a method for regulating a heating, ventilation and / or air conditioning loop which makes it possible to remedy the drawback mentioned above.

STATEMENT OF THE INVENTION

The subject of the invention is therefore a method of regulating a heating, ventilation and / or air conditioning loop of an air flow intended for a passenger compartment of a motor vehicle inside which a refrigerant circulates, said loop comprising at least one compressor and one condenser, the loop being configured to operate in heat pump mode according to a first closed circuit comprising the compressor and the condenser, the loop being configured to circulate the fluid according to a second closed circuit in which the fluid passes successively at least through the compressor and then the condenser by short-circuiting in part the first closed circuit while undergoing expansion before passing again through the compressor, said regulation method comprising a step, called pumping step, in which the loop is configured for that the refrigerant circulating according to the first closed circuit is directed from the first closed circuit in the second closed circuit.

When the refrigerant circulates according to the second circuit, great heating power is available thanks to the energy supplied by the compressor. The invention consists in using an expansion of the fluid which is reinjected into the compressor without being cooled beforehand. This makes it possible to have a warmer refrigerant at the outlet of the compressor and thus to have greater heating power at the level of the condenser, this by exploiting the components of the loop also serving for its conventional functions and therefore without increasing the cost. its cost, in particular in comparison with the additional cost of an additional heating device.

For example, according to the second circuit, using a refrigerant R134a or R1234yf and when the outside temperature is -18 ° C, the available heating power can reach 4000 to 5000 W.

According to another characteristic of the invention, the invention comprises a step subsequent to the pumping step, called the priming step, in which the first closed circuit and the second closed circuit are disconnected from one another.

According to another characteristic of the invention, during the priming step, a water pump of the second closed circuit is deactivated.

According to another characteristic of the invention, during the priming step, a pulser for setting in motion the air flow intended for the passenger compartment is deactivated.

According to another characteristic of the invention, the method comprises a step subsequent to the priming step, called the ramp-up step, during which the heating loop is configured so that the air flow which feeds the cabin and is heated by a heating radiator supplied by a flow of water set in motion by the water pump.

According to another characteristic of the invention, the method comprises a step subsequent to the step up in power, called the power stabilization step, during which the flow rate of the air flow heated by the heating radiator is increased. from the second closed circuit and / or a water flow from a water pump from the second closed circuit.

According to another characteristic of the invention, the priming step is triggered when a pressure of the refrigerant in a heat exchanger of the first closed circuit decreases until reaching a threshold pressure value.

According to another characteristic of the invention, the ramp-up step is triggered when a pressure of the refrigerant leaving the compressor of the second closed circuit becomes greater than a first pressure threshold value.

According to another characteristic of the invention, the power stabilization step is triggered when a pressure of the refrigerant leaving the compressor of the second closed circuit becomes greater than a pressure threshold value.

According to another characteristic of the invention, the power stabilization step is triggered when a water temperature circulating in a water pump of the second closed circuit is above a threshold temperature value.

According to another characteristic of the invention, the pumping step is triggered when an outside temperature is between a first temperature and a second temperature.

According to another characteristic of the invention, during the pumping step, the refrigerant circulates from a heat exchanger via an expansion member and an evaporator of the first closed circuit in the compressor of the second closed circuit then in a condenser , and an expansion member of the second closed circuit.

According to another characteristic of the invention, during the priming step, the refrigerant circulates from the compressor in the condenser of the second closed circuit, said at least one connection and disconnection valve being configured in the disconnection position of the first closed circuit of the second closed circuit.

The subject of the invention is also a process for thermal pre-conditioning of a passenger compartment of a motor vehicle, comprising a regulation process as described above.

DESCRIPTION OF THE FIGURES

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description given below for information only in relation to the drawings in which:

- Figure 1 is a schematic view of a first embodiment of a

0 heating, ventilation and / or air conditioning installation,

- Figure 2 is a view of the installation of Figure 1, according to a first mode of operation,

- Figure 3 is a view of the installation of Figure 1, according to a second mode of operation,

FIG. 4 is a view of the installation of FIG. 1, according to a third mode of operation,

FIG. 5 is a view of the installation of FIG. 1, according to a fourth mode of operation,

- Figure 6 is a timing diagram of a process for regulating the installation

0 of FIG. 1, according to the present invention,

- Figure 7 is a view of the installation of Figure 1 in a pumping step of the process of Figure 6,

FIG. 8 is a view of the installation of FIG. 1 in a priming, ramp-up or power stabilization step of the process of FIG. 6,

- Figure 9 is a view of the installation of Figure 1 equipped with pressure and temperature sensors for the implementation of the method of Figure 6, and

FIG. 10 illustrates an evolution of different parameters during the regulation process of FIG. 6.

DETAILED DESCRIPTION Structure of the loop îo FIG. 1 illustrates a heating, ventilation and / or air conditioning installation able to modify the aerothermal parameters of an air flow F intended to enter a passenger compartment of a vehicle, in particular a vehicle electric or hybrid. The heating, ventilation and / or air conditioning installation 1 comprises a heating, ventilation and / or air conditioning device 2 capable of controlling the air flow

F prior to its introduction into the passenger compartment of the vehicle.

The device 2 is delimited by a box 3, for example made of polymer material, and comprises a blower 4 located inside the box 3 and able to generate the air flow F from at least one intake orifice 5 towards at least one exhaust port 6 made in the housing 3, the air flow F coming from the orifice

0 exhaust 6 joining the passenger compartment of the vehicle.

According to a first embodiment shown in the figures, to modify the temperature of the air flow F prior to its introduction into the passenger compartment, the heating, ventilation and / or air conditioning installation 1 comprises:

• a heating, ventilation and / or air conditioning loop 7 inside which a refrigerant circulates, such as a refrigerant known under the name R134a or R1234yf;

• a heating circuit 8 inside which a heat transfer fluid circulates.

The heating, ventilation and / or air conditioning loop 7 comprises a condenser 9, a heat exchanger 10 capable of forming a condenser or an evaporator, an evaporator 11, a first expansion member D1, a second expansion member D2, a third expansion member D3, a compressor 12, a bottle R of fluid reserve, a first stop valve V1, a second stop valve V2, a third stop valve V3, a fourth stop valve V4 and a fifth stop valve V5.

According to the first embodiment, the condenser 9 is configured to perform a heat exchange between the refrigerant and the heat transfer fluid of the heating circuit 8.

More specifically, the condenser 9 comprises two independent paths, namely a primary path and a secondary path. The primary path is traversed by the refrigerant from a primary inlet 13 to a primary outlet 14. The secondary path is traversed by the heat transfer fluid from a secondary inlet 15 to a secondary outlet 16.

The heat exchanger 10, more commonly known as an evapo-condenser, can be placed on the front face of the vehicle, so as to exchange heat with the outside air E of the vehicle.

The evaporator 11 is located in the housing 3 of the installation 1 downstream of the blower 4 in the direction of circulation of the air flow F inside the housing 3, so as to exchange heat with the flow d air F intended to enter the passenger compartment of the vehicle.

The first, second and third expansion members D1, D2, D3 allow expansion of the refrigerant from high pressure to low pressure.

Each expansion member D1, D2, D3 is movable between an open position in which the fluid can pass through it and is expanded at the outlet thereof, and a closed position in which the fluid cannot pass through it, and in other words, the expansion member D1, D2, D3 is sealed whatever the direction of circulation of the fluid.

Each expansion member D1, D2, D3 can be an electronically controlled regulator or a calibrated orifice.

The compressor 12 is able to bring the refrigerant to a high pressure.

The bottle R also advantageously makes it possible to carry out a separation of liquid / gas phases in order to prevent refrigerant in the liquid state from being admitted inside the compressor 12.

Each stop valve V1, V2, V3, V4, V5 is movable between an open position in which the fluid can pass through it, and a closed position in which the fluid cannot pass through it, and in other words, the valve V1, V2, V3, V4, V5 is sealed regardless of the direction of circulation of the fluid.

In the case where a stop valve V1, V2, V3, V4, V5 is completely sealed only in one direction of circulation of the fluid in the closed position, the valve can be associated with a non-return valve to obtain a total seal which whatever the direction of circulation of the fluid.

As illustrated in FIG. 1, the heating, ventilation and / or air conditioning loop 7 also comprises:

- a first portion P1 connecting the bottle R to the inlet of the compressor 12,

a second portion P2 connecting the outlet of the compressor 12 to a first branch E1,

a third portion P3 connecting the first branch E1 to the primary input 13 of the condenser 9,

a fourth portion P4 connecting the first branch E1 to the first valve V1,

a fifth portion P5 connecting the first valve V1 to a second branch E2,

a sixth portion P6 connecting the primary outlet 14 of the condenser 9 to the second valve V2,

a seventh portion P7 connecting the second valve V2 to the second branch E2,

an eighth portion P8 connecting the second branch E2 to a third branch E3,

a ninth portion P9 connecting the third branch E3 to a fourth branch E4,

a tenth portion P10 connecting the fourth branch E4 to the third expansion member D3,

an eleventh portion P11 connecting the third expansion member D3 to a fifth branch E5,

a twelfth portion P12 connecting the fourth branch E4 to the fifth valve V5,

a thirteenth portion P13 connecting the fifth valve V5 to the fifth branch E5,

- a fourteenth portion P14 connecting the fifth branch E5 to the inlet of the heat exchanger 10,

- a fifteenth portion P15 connecting the outlet of the heat exchanger 10 to the sixth branch E6,

a sixteenth portion P16 connecting the sixth branch E6 to the second expansion member D2,

a seventeenth portion P17 connecting the second expansion member D2 to the inlet of the evaporator 11,

- an eighteenth portion P18 connecting the outlet of the evaporator 11 to the fourth valve V4,

a nineteenth portion P19 connecting the fourth valve V4 to a seventh branch E7,

a twentieth portion P20 connecting the sixth branch E6 to the third valve V3,

a twenty-first portion P21 connecting the third valve V3 to the seventh branch E7,

- a twenty-second portion P22 connecting the seventh branch E7 to the bottle R,

a twenty-third portion P23 connecting the third branch E3 to the first expansion member D1,

- A twenty-fourth portion P24 connecting the first expansion member D1 to the seventh branch E7.

It should be noted that a portion is understood to mean any device making it possible to establish a fluid connection such as, for example, a pipe, a pipe or a tube.

It is also noted that one or more of these portions can be taken in isolation from each other or in combination with each other. In addition, the numbering of the portions is only indicative.

Within the meaning of the invention, the portion of the loop 7 between the third branch E3 and the seventh branch E7, and in other words the assembly comprising the twenty-third portion P23, the first expansion member D1 and the twenty-fourth portion P24, represents a branch of short3057211 circuiting also called bypass branch.

In the present application, the term "short-circuiting branch" means a branch which allows the refrigerant to bypass certain components of the heating, ventilation and / or air conditioning loop 7.

The heating circuit 8 comprises a pump 17 and a heating radiator 18. The heat transfer fluid exchanges heat with the refrigerant through the condenser 9.

The pump 17 is able to circulate the heat transfer fluid in the circuit 8.

The heating radiator 18 is located in the housing 3 downstream of the evaporator 11 in the direction of circulation of the air flow F inside the housing 3, so as to exchange heat with the flow of air F intended to enter the passenger compartment of the vehicle.

The device 2 comprises various maneuverable flaps (not shown) located in the housing 3, these flaps making it possible to control the passage of the air flow

F through the evaporator 11 and / or the heating radiator 18, upstream of its introduction into the passenger compartment of the vehicle.

As illustrated in FIG. 1, the heating circuit 8 further comprises:

- a twenty-fifth portion P25 connecting the outlet of the pump 17 to the secondary inlet 15 of the condenser 9,

0 - a twenty-sixth portion P26 connecting the secondary output 16 of the condenser 9 to the input of the heating radiator 18,

- a twenty-seventh portion P27 connecting the outlet of the heating radiator 18 to the inlet of the pump 17.

It should be noted that a portion is understood to mean any device making it possible to establish a fluid connection such as, for example, a pipe, a pipe or a tube.

It will be noted that, in FIGS. 2 to 5, the elements which are not traversed by the refrigerant or the heat transfer fluid in the operating mode considered have been shown in dotted lines, the others being shown in solid lines.

0 Operating modes

FIG. 2 illustrates a first operating mode of the installation 1, also called "heat pump mode" or "heating mode", in which the refrigerant of loop 7 circulates according to a first closed circuit. In this first operating mode, the pump 17 is started, the compressor 12 is started, the first valve V1 is closed, the second valve V2 is open, the third valve V3 is open, the fourth valve V4 is closed, the fifth valve V5 is closed, the first expansion member D1 is closed, the second expansion member D2 is closed, the third expansion member D3 is open and the heat exchanger 10 forms an evaporator.

In this first operating mode, the refrigerant successively passes through the compressor 12, the condenser 9, the second valve V2, the third expansion member D3, the heat exchanger 10 forming an evaporator, the third valve V3 then the bottle R before crossing compressor 12 again.

In this first mode of operation, the heat exchanger 10 recovers heat outside. The air flow F intended to enter the passenger compartment exchanges heat with the heating radiator 18, and more precisely the air flow F is heated as it passes through the heating radiator 18.

FIG. 3 illustrates a second operating mode of the installation 1, also called "hot gas mode", in which the refrigerant of the loop 7 circulates in a second closed circuit. In this second mode of

0 operation, the pump 17 is started, the compressor 12 is started, the first valve V1 is closed, the second valve V2 is open, the third valve V3 is closed, the fourth valve V4 is closed, the fifth valve V5 is closed, the first detent member D1 is open, the second detent member D2 is closed, the third detent member D3 is closed.

In this second operating mode, the refrigerant successively passes through the compressor 12, the condenser 9, the second valve V2, the first expansion member D1 then the bottle R before again passing through the compressor 12.

In this second operating mode, the air flow F intended to penetrate

0 in the passenger compartment exchanges heat with the heating radiator 18, and more precisely the air flow F is heated as it passes through the heating radiator 18.

By way of comparison with the first operating mode, the fact that after its expansion, the fluid is reinjected into the compressor 12 without being cooled beforehand allows according to the invention to have a warmer refrigerant at the outlet of compressor 12, a warmer heat transfer fluid and thus as a rule to have greater heating power.

According to the second operating mode, for example, using a refrigerant R134a or R1234yf and when the outside air temperature is -18 ° C, the available heating power is 5000 W.

According to the second operating mode, the second circuit advantageously has a minimum volume to ensure the most efficient energy transfer possible. For this, the second circuit advantageously comprises a charging buffer which may take the form of an extension of the circuit, of a reservoir such as the bottle R or the like.

FIG. 4 illustrates a third operating mode of the installation 1, also called "air conditioning mode", in which the refrigerant of the loop 7 circulates in a third closed circuit. In this third operating mode, the pump 17 is stopped, the compressor 12 is started, the first valve V1 is open, the second valve V2 is closed, the third valve V3 is closed, the fourth valve V4 is open, the fifth valve V5 is open, the first expansion member D1 is closed, the second expansion member D2 is open, the third expansion member D3 is closed and the heat exchanger 10 forms a condenser.

In this third operating mode, the refrigerant successively passes through the compressor 12, the first valve V1, the fifth valve V5, the heat exchanger 10 forming a condenser, the second expansion member D2, the evaporator 11, the fourth valve V4 then the bottle R before crossing again the compressor 12.

In this third mode of operation, the heat exchanger 10 dissipates heat outside. The air flow F intended to enter the passenger compartment exchanges heat with the evaporator 11, and more precisely the air flow F is cooled during its passage through the evaporator 11. The fact that the refrigerant bypasses the condenser 9 via the first valve V1 makes it possible to prevent the heat transfer fluid from boiling.

FIG. 5 illustrates a fourth operating mode of the installation 1, also called "dehumidification mode", in which the refrigerant of the loop 7 circulates according to a fourth closed circuit. In this fourth operating mode, the pump 17 is started, the compressor 12 is started, the first valve V1 is closed, the second valve V2 is open, the third valve V3 is closed, the fourth valve V4 is open, the fifth valve V5 is open, the first expansion member D1 is closed, the second expansion member D2 is open, the third expansion member D3 is closed and the heat exchanger 10 forms a condenser.

In this fourth operating mode, the refrigerant successively passes through the compressor 12, the condenser 9, the second valve V2, the fifth valve V5, the heat exchanger 10 forming a condenser, the second expansion member D2, the evaporator 11, the fourth valve V4 then the bottle R before crossing again the compressor 12.

In this fourth operating mode, the heat exchanger 10 15 dissipates heat outside. The air flow F intended to enter the passenger compartment exchanges heat with the evaporator 11 then the heating radiator 18, and more precisely the air flow F is firstly cooled during its passage through the evaporator 11, then in a second step, is heated during its passage through the heating radiator 18 so that the air flow F is dehumidified.

According to a second embodiment not shown in the figures, to modify the temperature of the air flow prior to its introduction into the passenger compartment, the heating, ventilation and / or air conditioning installation only includes the heating loop 7, ventilation and / or air conditioning inside which the refrigerant circulates.

According to the second embodiment, the condenser 9 is located in the housing 3 downstream of the evaporator 11 according to the direction of circulation of the air flow inside the housing 3, so as to exchange heat with the air flow F intended to enter the passenger compartment of the vehicle.

0 According to the second embodiment, the various maneuverable flaps (not shown) located in the housing 3 make it possible to control the passage of the air flow F through the evaporator 11 and / or the condenser 9, upstream of its introduction into the passenger compartment of the vehicle.

Thus, according to the second embodiment, according to the operating mode, the fluid intended to enter the passenger compartment exchanges heat with:

• the condenser 9, according to the first operating mode, • the condenser 9, according to the second operating mode, • the evaporator 11, according to the third operating mode, • the evaporator 11 then with the condenser 9, according to the fourth mode of operation.

Depending on the refrigerant, the internal diameter of the different valves V1, V2, V3, V4, V5 is chosen so as to have a good compromise, in operation, between the pressure of the refrigerant and the amount of refrigerant present in the loop 7.

Thus, for a refrigerant known under the name R134a or R1234yf, advantageously, the internal diameter of the various valves V1, V2, V3, V4 is chosen as follows:

• the internal diameter of the first valve V1 is between 4 mm and 8 mm, and is for example 6 mm, • the internal diameter of the second valve V2 is between 4 mm and 8 mm, and is for example 6 mm, • the internal diameter of the third valve V3 is between 14 mm and 18 mm, and is for example 16 mm, • the internal diameter of the fourth valve V4 is between 14 mm and 18 mm, and is for example 16 mm.

According to a variant of the first or second embodiment, not shown, the first and second stop valves V1, V2 can be replaced by a valve comprising three ways.

According to a second variant of the first or second embodiment, not shown, which can be combined with the first variant, the fifth stop valve V5 and the third expansion member D3 can be replaced by a specific valve capable of occupying the following positions :

• a first open position in which the fluid can pass through it and is expanded at the outlet thereof (first operating mode);

• a second open position in which the fluid can pass through it and is not relaxed at the outlet thereof (third and fourth operating modes);

• a closed position in which the fluid cannot pass through it, the valve being sealed regardless of the direction of circulation of the fluid (second operating mode).

Method of regulating the second operating mode

The subject of the invention is a method for regulating the second operating mode, or "hot gas mode" described above.

As shown in FIG. 6, the regulation method 60 advantageously comprises a succession of four steps, namely a first step, called the pumping step, referenced 61, followed by a second step 62, called the priming step, a third step 63, called the ramp-up step and a fourth step 64, called the power stabilization step.

The steps of the regulation process will now be described in relation to different parameters.

State of the valves and expansion devices

As visible in Figure 7, during pumping step 61:

- the shut-off valves V1 and V5 are closed,

- the shut-off valves V2, V3 and V4 are open, and

- the first and the second expansion member, D1 and D2, are open.

In the pumping step 61, the refrigerant flows from the heat exchanger 10 to the compressor 12 via the stop valve V3 and via the evaporator 11.

Thus, the first closed circuit 100 discharges the refrigerant in the second closed circuit 101.

As can be seen in the figures, the first closed circuit 100 includes the heat exchanger 10, the expansion member D2, the evaporator 11, the shut-off valves V3, V4 and V5.

The second closed circuit 101 includes the bottle R, the compressor 12, the shut-off valves V1 and V2, the condenser 9 and the expansion member D1.

The shut-off valves V3, V4 and V5 are used to connect or disconnect the first closed circuit 100 from the second closed circuit 101.

Between the pumping stage and the following stages, the shut-off valves V3 and V4 change state from the closed state to the open state.

As can be seen in FIG. 8, during the priming steps 62, ramp-up 63 and power stabilization 64:

- the shut-off valves V1 and V5 are closed,

- the second stop valve V2 is open,

- the third and fourth stop valves V3 and V4 are closed, and

- the first and the second expansion member, D1 and D2, are open.

In the priming 62, power-up 63 and power stabilization 64 steps, the loop operates in "hot gas" mode already described in relation to FIG. 3.

Water flow

In the pumping step 61, the pump 17 operates, so that the water circulates in the condenser 9 and in the heating radiator 18.

Preferably, the pump 17 operates in nominal mode.

For example, in nominal mode, the water flow is between 100 and 250 l / h.

In the priming step 62, the pump 17 is stopped; there is no water flow in the condenser 9 and the heating radiator 18.

0 In the ramp-up step 63, the pump 17 operates, so that the water circulates in the condenser 9 and in the heating radiator 18.

Preferably, the pump 17 operates in nominal mode.

For example, in nominal mode, the water flow is between 100 and 250 l / h.

In the power stabilization step 64, the pump 17 operates, so that the water circulates in the condenser 9 and in the heating radiator 18.

Preferably, the pump 17 operates at maximum speed.

For example, the speed of the pump will correspond to a water flow of between 300 and 750 l / h.

0 Pulser speed

In the pumping step 61, the speed of the blower 4 is preferably a minimum speed. For example, the speed of the blower will correspond to a passenger compartment air flow of between 100 and 150 kg / h.

In the priming step 62, the blower 4 is stopped, so that the passenger compartment is not supplied with air.

In the ramp-up step 63, the speed of the blower 4 is preferably greater than its speed in the pumping step.

Advantageously, the speed of the blower 4 is adjusted according to the rise in temperature of the water.

In the power stabilization step 64, the speed of the blower 4 is equal to its speed in the ramp-up step.

Compressor speed îo Alternatively, the speed of compressor 12 is maximum in each of the pumping 61, priming 62, ramp-up 63 and power stabilization 64 steps.

Advantageously, the speed of the compressor is lower than a limit speed of acoustic comfort.

According to another variant, the speed of the compressor 12 depends on the steps, as will be detailed later.

Sensors

As shown in FIG. 9, the installation 1 implementing the loop 7 comprises a plurality of sensors.

0 Installation 1 includes a first refrigerant pressure sensor

91. The first pressure sensor 91 is arranged at the inlet of the compressor in the branch P1 connecting the bottle to the compressor 12.

Installation 1 includes a second refrigerant pressure sensor 92 (PRCO).

The second pressure sensor 92 is disposed at the outlet of the compressor

12, in the branch Pi connecting the compressor 12 and the condenser 9.

The installation 1 also includes a third refrigerant pressure sensor 93 (PRECO) at the outlet of the heat exchanger 10.

Installation 1 also includes a temperature sensor 94 (TAMB)

0 configured to measure the temperature of the air flow entering the heat exchanger 10.

The system 7 also includes a temperature sensor 95 (TWCDO) configured to measure the temperature of the water leaving the condenser 9.

According to a variant not illustrated, the pressure sensor 91 and / or the pressure sensor 93 are replaced respectively by a temperature sensor TRCI and a temperature sensor TRECO.

Each of the temperature sensors is in this case configured to measure the temperature of the refrigerant and / or the temperature of the walls respectively forming the branch P1 connecting the bottle R to the compressor 12 and the branch P15 connecting the heat exchanger 10 to l 'branch E6.

According to another variant not illustrated, the second temperature sensor 91 is not installed.

îo In this case, the pressure is calculated on the basis of the measurement of the sensor 93 and of a low pressure model between the outlet of the exchanger 10 and the inlet of the compressor 12, taking account of pressure drop in the branches of the loop.

As shown in Figure 9, the installation includes a control unit

96 to which each sensor is connected.

Trigger temperatures for "hot gas" and "heat pump" modes

The "hot gas" mode is triggered when the outside air temperature is between two temperatures marked TO and T1, TO being less than T1.

0 For example, the temperature T0 is around -25 ° C, while the temperature T1 is around -10 ° C.

The "heat pump" mode is triggered when the outside air temperature is between the temperature T1, and a third temperature T2, higher than TO.

For example, the temperature T2 is around 5 ° C.

Preferably, other conditions must be met to trigger the "hot gas" mode, as will be detailed.

Parameters for triggering successive steps

The following parameters are used to successively trigger the 30 pumping steps 61, priming 62, ramp-up 63 and power stabilization 64 of the "hot gas" mode:

- speed of compressor 12, noted Ncpr (expressed in revolutions per minute or rpm);

- voltage at the terminals of pump 12, Upomp (expressed in V);

- voltage across the pulser 4, Uhvac (expressed in V);

- voltage across a mixing panel 181, Umixflap (expressed in V);

- voltage at the terminals of each stop valve V1 to V5 (expressed in V); and

- voltage at the terminals of a blower 182 disposed at the outlet of the heat exchanger 10, Ufrontend (expressed in V).

When the temperature conditions are met, the "hot gas" mode is advantageously triggered if the following conditions are met:

îo - the inlet pressure of the compressor, possibly measured by the first pressure sensor 91, is greater than a threshold pressure value, denoted PRCImin,

the pressure at the outlet of the compressor possibly measured by the first pressure sensor 92 is less than a threshold pressure value, denoted PRCOmaxHP,

- the water temperature at the outlet of the condenser 9, possibly measured by the temperature sensor 95, is lower than a threshold temperature value, noted TWCDOmax,

- the outside temperature, also measured by the

0 temperature 94, is between the lower threshold value TO and the upper threshold value T1.

For example, the threshold pressure value PRCImin is between 0.7 bar and 1.2 bar.

For example, the PRCOmaxHP threshold pressure value is between 16 25 bar and 24 bar.

For example, the TWCDOmax threshold temperature value is around ° C.

For example, the threshold temperature value T0 is around -25 ° C and the threshold temperature T1 is around -10 ° C.

Once the "hot gas" mode is engaged, the pumping step 61 starts, according to the following state of parameters:

- as already indicated, the valves V1 and V5 are closed while the valves V3 and V4 are open,

- the voltage across the pump 17 Upomp is set to an UpompHGI value, which advantageously depends on the outside temperature,

- the voltage across the pulser 4 Uhvac is set to a Ublowerl value,

- the voltage across the Umixflap mixing flap is set to the maximum hot air passage position;

- the compressor speed 12 Ncpr is set to a value NcprHGI, preferably between 5000 rpm and 7000 rpm.

These parameters are maintained in the state indicated above as long as the pressure at the outlet of the heat exchanger 10, possibly measured by the pressure sensor 93, is greater than the threshold pressure value PRCImin reduced by a given value DP, for example between 0.1 bar and 0.3 bar.

When the pressure at the outlet of the heat exchanger 10 becomes less than or equal to the threshold pressure value PRCImin reduced by a given value DP, the priming step 92 is triggered, preferably according to the following state of the parameters :

- as already indicated, the valves V3 and V4 close,

the voltage at the terminals of the pump 12 Upomp is adjusted to a value UpompHG2, advantageously zero,

- the voltage across pulser 4, Uhvac, is set to UblowerO, preferably zero,

- the compressor speed 12 Ncpr is set to a maximum value, Ncprmax, which preferably depends on the speed of the vehicle and / or on a request from a user.

These parameters are maintained in the state indicated above as long as the pressure at the outlet of the compressor 12, possibly measured by the pressure sensor 92, is less than a threshold pressure value PRCOmaxHG, for example between 16 bar and 24 bar .

When the pressure at the outlet of compressor 12 becomes greater than or equal to the threshold pressure value PRCOmaxHG, the ramp-up step 63 is triggered, preferably according to the following state of parameters:

- as already indicated, the valves remain in the same state as in priming step 62,

- the voltage across the pump 17 Upomp is set to an UpompHG3 value, so that the water flow rate is advantageously between 1001 / h and 250 l / h,

- the voltage across the pulser 4 Uhvac is set to the value Ublower îo HG, and

- the compressor speed 12 Ncpr is set to the maximum value, Ncprmax.

These parameters are maintained in the state indicated above as long as the water temperature at the outlet of the condenser 9, possibly measured by the temperature sensor 95 is less than a threshold temperature value, denoted TWCDOtarget, and as long as the pressure at the outlet of compressor 12 is lower than the threshold pressure value PRCOmaxHG.

0 When the water temperature at the outlet of the condenser 9 becomes higher than the threshold temperature value TWCDOtarget and / or the pressure at the outlet of the compressor 12 becomes higher than the threshold pressure value PRCOmaxHG, the power stabilization step 64 is triggered, preferably according to the following state of the parameters:

- as already indicated, the valves remain in the same state as in priming step 62,

- the voltage across the pump 17 Upomp is set to an UpompHG4 value, so that the water flow rate is advantageously between 300l / h and 750l / h,

- the voltage across the 4 Uhvac pulser is set to a value

UblowerHG, and

- the compressor speed 12 Ncpr is set to the maximum value, Ncprmax.

In the power stabilization step 64, the speed of the compressor is regulated so that the water temperature TWCDO reaches its TWCDOtarget setpoint, while respecting the limit of the maximum compressor outlet pressure threshold equal to PRCOmaxHG.

Experimental curves

As visible in FIG. 10, the curve 10-1 illustrates the evolution over time of the pressure at the outlet of the compressor 12.

As shown in FIG. 10, the pressure of the refrigerant at the outlet of the compressor 12 gradually increases during the pumping step 61 then, more rapidly during the priming step 62.

At the end of the priming step 62, the pressure decreases before gradually increasing again during the ramp-up 63 and stabilization 64 steps.

Curve 10-2 illustrates the evolution over time of the temperature of air blown into the passenger compartment.

As shown in FIG. 10, the air temperature gradually increases during the pumping step 61 before decreasing during the priming step 62, due to the stopping of the blower 4.

Then the temperature gradually increases again during the ramp-up 63 and stabilization 64 steps.

Curve 10-3 illustrates the evolution over time of the water flow in the pump.

As shown in FIG. 10, the water flow rate gradually increases during the pumping step 61 before decreasing during the priming step 62 until it becomes zero, due to the stopping of the pump.

Then, the water flow gradually increases again during the ramp-up 63 and stabilization 64 steps.

Curves 10-1 to 10-3 are obtained with the following experimental parameters:

- in the pumping step 61, the speed of the compressor 12 is between 5000 rpm and 7000 rpm, the pump flow 17 is around 130 l / h and the air flow in the passenger compartment is adjusted at least ;

- in priming step 62, the speed of the compressor is of the order of

8500 rpm and the air flow in the passenger compartment is set to minimum;

- in the ramp-up step 63, the speed of the compressor 12 is around 8500 rpm, the pump flow 17 is around 150 l / h until the pressure at the outlet of the compressor is around 20 bar and the air flow in the passenger compartment is set to the maximum; and

in the stabilization step 64, the speed of the compressor 12 is around 8500 rpm, the pump flow 17 is around 600 l / h to maintain the pressure at the outlet of the compressor at 20 bar and the air flow in the passenger compartment is set to the maximum.

îo As can be seen in FIG. 10, after 17 min, a power of 4650 W is obtained.

As also shown in FIG. 10, the pumping step lasts 3 minutes, the priming step lasts 2 minutes and the ramp-up step lasts 10 minutes.

Thermal preconditioning process

Advantageously, the invention also relates to a method of thermal preconditioning of a passenger compartment of a motor vehicle, comprising the regulation method 60.

The thermal preconditioning process allows the vehicle to be thermally prepared before use.

Thus, the method 60 is preferably implemented before a user uses his motor vehicle.

Claims (11)

1. Method for regulating a heating, ventilation and / or air conditioning loop (7) of an air flow intended for a passenger compartment of a motor vehicle inside which a refrigerant circulates, said loop comprising at least a compressor (12) and a condenser (9), the loop (7) being configured to operate in heat pump mode according to a first closed circuit comprising the compressor (12) and the condenser (9), the loop (7) being configured to circulate the fluid in a second closed circuit in which the fluid successively passes through at least the compressor (12) then the condenser (9) by partially short-circuiting the first closed circuit while undergoing expansion before crossing again the compressor (12), said regulation method comprising a step, called pumping step (61), in which the loop (7) is configured so that the refrigerant circulating according to the first closed circuit is directed ige from the first closed circuit in the second closed circuit. 2. A method of regulating a heating, ventilation and / or air conditioning loop according to claim 1, comprising a step subsequent to the pumping step, called the priming step (62), in which the first closed circuit and the second closed circuit are disconnected from each other. 3. Method according to the preceding claim, wherein, during the priming step (62), a water pump (17) of the second closed circuit is deactivated. 4. The method of claim 3, wherein, during the priming step, a blower (4) for setting in motion the air flow intended for the passenger compartment is deactivated. 5. Method according to one of claims 3 or 4, comprising a step subsequent to the priming step (62), called the ramp-up step (63), during which the heating loop is configured so that the air flow supplies the passenger compartment and is heated by a heating radiator (18) supplied by a flow of water set in motion by the water pump (17). 6. Method according to the preceding claim, comprising a step subsequent to the step up in power (63), said step of power stabilization (64), during which the flow rate of the air flow heated by the heating radiator (18) of the second closed circuit and / or a water flow from a water pump (17) of the second closed circuit. 7. Method according to one of the preceding claims, in which the step Priming 5 (62) is triggered when a pressure of the refrigerant in a heat exchanger (10) of the first closed circuit decreases until reaching a pressure threshold value. 8. Method according to one of claims 5 to 7, wherein the step of ramp-up (63) is triggered when a pressure of the refrigerant fluid at the outlet of the compressor (12) of the second closed circuit becomes greater than a value pressure threshold. 9. Method according to the preceding claim, in which the power stabilization step (63) is triggered when a pressure of the refrigerant leaving the compressor (12) of the second closed circuit becomes 15 greater than a pressure threshold value. 10. Method according to one of claims 6 to 9, in which the power stabilization step (64) is triggered when a water temperature circulating in a water pump (17) of the second closed circuit is greater than a temperature threshold value. 2 0 11. Method according to one of the preceding claims, in which the pumping step (61) is triggered when an outside temperature is between a first temperature and a second temperature. 1/6