Thermal regulator for motor vehicle air conditioning has regulating heat exchanger with hot and cold heat exchange circuit sections controlled by stop and distributor valves

The present invention relates to a temperature control device of air flowing in a motor vehicle.

In particular the invention relates to thermal control of the intake air of a supercharged engine optionally connected to an exhaust line provided with a particle filter.

Already known in the prior art, in particular after US-A -4 096,697, a device for controlling the temperature of air flowing into a motor vehicle, of the type comprising a air/heat transfer fluid heat exchanger, said exchanger control, connected to a first called cold circuit of heat transfer liquid, for cooling the air, and a second called hot circuit of heat transfer liquid, for reheating the air, by means of liquid distribution cold and hot heat transfer in the exchanger control.

In US-A -4 096,697, the temperature-controlled air is the intake air of an internal combustion engine of the motor vehicle. The engine is supercharged by means of a turbo-compressor assembly having, on the one hand, a turbine driven by the exhaust gas of the engine, arranged downstream of the engine, and on the other hand, of an intake air compressor located upstream of the motor. The inlet air of the engine, warming in the compressor, is cooled at the outlet of the compressor, using the above heat control device, to optimize performance of the engine, during operation to normal operation, and minimizing the emissions of pollutants.

US-A -4 096,697 also provides for heating the intake air of the engine at the outlet of the compressor using the device for controlling the temperature of the aforementioned type, to optimize performance of the engine when starting the latter or its low-load operation.

It is also intended to heat the intake air for an engine as when the vehicle is connected to an exhaust system provided with a particle filter. The filter is to be regenerated periodically to remove the soot particles that accumulate. Intake air is to be heated to a temperature sufficient, this condition being required for proper operation of the complete device regeneration (combustion of soot stored).

The thermal control device of the aforementioned type is for both cooling that heating the intake air to the same exchanger means of a control dedicated to these two functions.

However, the thermal power to be output by the exchanger control is generally much higher, during cooling of the intake air that, in the heating of the intake air.

Indeed, under the conditions for cooling the inlet air the more frequent, the exchanger thermal power required, control is of the order of 10 to 25 kW. In contrast, under the conditions of air intake heating most frequent, the exchanger thermal power required, control is of the order of 1 to 3 kW.

The thus comprises that the dimensions of the exchanger control is imposed by the power required for cooling the intake air. Therefore, the heat exchanger is generally proper sized for its function for cooling intake air but oversized to its heating function of the intake air. This poses a problem of thermal inertia control of the exchanger in particular when switching from heating regime of the intake air to a cooling regimen of the intake air. The thermal inertia has an adverse effect on the operation of the vehicle engine.

The invention aims at enabling both cool that heat the intake air for an engine of a vehicle by means of an exchanger dedicated regulating same to these two functions, by overcoming the problem of thermal inertia above-mentioned.

To this end, the invention relates to a device for controlling the temperature of air flowing into a motor vehicle, of the aforementioned type, characterized in that the exchanger comprises:

-two parts for circulating the heat transfer liquid connected to the distribution means, and

-means for selective blocking for circulating the heat transfer liquid in one of the parts, said portion closable.

In other characteristics of the device:

selective-the stop means for circulating the heat transfer liquid comprises means for closing a passage of a heat transfer liquid, said closeable passage connected to the part which can be closed so that the passage portion and closable are traversed by a common flow of coolant when the closable passage is not blocked;

-the sealing means comprises a valve selected from a on-off solenoid valve and a thermostatic valve;

-the two parts for circulating the heat transfer liquid are connected to a common input connected to the coolant distribution means, each circulation part of the cooling liquid being connected to a coolant outlet which is specific to it, the occlusion means being arranged in one of the outputs of heat transfer liquid, said closeable outlet;

control-the exchanger is of the plate type;

-the air is the intake air of an internal combustion engine of the motor vehicle;

-the intake air is driven, at a pressure greater than atmospheric pressure, through the exchanger control, by a turbo-compressor assembly having a turbine driven by the exhaust gas of the internal combustion engine;

-the first cold heat-transfer liquid circuit comprises a air/heat transfer fluid heat exchanger, said low temperature heat exchanger, and preferably carried on a front face of the motor vehicle;

-the cold heat transfer liquid is circulated in the first circuit by a pump;

-the second hot heat-transfer liquid circuit is connected to a cooling circuit of the internal combustion engine;

-the second hot heat-transfer liquid circuit is connected to a heat exchanger forming a hot source of a heat pump;

-the distribution means comprises a distribution valve, three-way, comprising a first path of coolant inlet connected to the first heat-transfer liquid circuit, a second way of coolant inlet connected to the second circuit of the heat transfer liquid and a third channel coolant outlet connected to a coolant inlet control in the exchanger;

-the internal combustion engine, e.g. of the diesel type, is connected to an exhaust system provided with a particle filter;

-the heat transfer liquid is a mixture of water and antifreeze.

The invention be included at the reading the description which will follow, given by way of example only and made with reference to the accompanying drawings in which:

-figure 1 is schematic view of an internal combustion engine connected to means upstream air intake circuit and to means forming downstream exhaust line;

figure 2 is a schematic view of a temperature control device according to the invention;

-figures 3 and 4 are schematic views of the exchanger-regulated in two operating configurations respectively.

The Figure 1 an internal combustion engine 10 of a motor vehicle, e.g. of the diesel type, connected to means forming a circuit 12 upstream of air flowing into the engine 10 and downstream means forming an exhaust line 14.

The engine 10 is supercharged by means of a turbo-compressor assembly having, on the one hand, of a turbine 16 driven by the exhaust gas from the engine 10, arranged downstream of the engine 10 in the exhaust line 14, and on the other hand, of a compressor 18 intake air located upstream of the motor 10 in the air intake circuit 12. The turbine 16 and the compressor 18 are coupled in rotation between them in a manner known per se.

The exhaust line is provided with a conventional particulate filter 19.

The temperature of the intake air leaving the compressor 18 is regulated by means of a thermal control device 20 according to the invention, one embodiment of which is shown in Figures 2 to 4.

On Figure 2, see that the device 20 comprises a heat exchanger 22 intake air/heat transfer fluid, said exchanger control, for regulating the temperature of the intake air leaving the compressor 18. The exchanger 22 described in greater detail subsequently.

The exchanger control 22 is connected to a first circuit 24 said cold heat transfer liquid, for cooling the intake air, and a second circuit 26 said hot heat transfer liquid, for heating the intake air, by means of liquid distribution cold and hot heat transfer in the exchanger 22.

The intake air is driven through the exchanger 22 control at a pressure higher than atmospheric pressure by the compressor 18. The intake air flow flowing through the exchanger 22 is represented in Figure 2 by arrows thick oriented left to right.

The distribution means comprise a standard three-way distribution valve 28, such as on/off or proportional type. The valve 28 comprises a first path of coolant inlet 28A first circuit 24 connected to the heat transfer liquid, a second inlet connected to the second heat transfer liquid 28B circuit 26 of the heat transfer liquid and a third channel of the coolant outlet 28C E connected to an inlet of heat-transfer liquid through the exchanger 22 control.

The cooling liquid flowing in each of the first and second circuits 24 26 is conventional and comprises, for example, a mixture of water and antifreeze.

The first circuit 24 cold heat transfer liquid comprises a conventional heat exchange outside air 30 to the vehicle and the cold heat-transfer liquid, called low temperature heat exchanger, preferably carried on a front face 31 of the motor vehicle. The cold heat transfer liquid is circulated in the first circuit 24 by a conventional electric pump 32.

The second circuit 26 hot heat-transfer liquid is connected for example with a conventional circuit for cooling the engine 10, not shown in Figures. Alternatively, the second circuit 26 can be connected to a heat exchanger forming a hot source of a heat pump or conventional connected to any other heat source.

The will describe in greater detail below the exchanger 22 control by referring to the Figures 3 and 4.

On these figures, see that the exchanger control 22 comprises two separate parts [...], 22B for circulating the heat transfer liquid connected to the common inlet E. The separation of these two parts [...], 22B is formed by a partition wall 34 shown diagrammatically.

Each portion [...], 22B for circulating the heat transfer liquid is connected to a coolant outlet SA, SB its own.

SA An output of coolant liquid is provided with means for obturation 36A. The output is said outlet closable SA.

The closure means 36A form means of selective blocking for circulating the heat transfer liquid in a portions [...], 22B control of the exchanger 22, in other words, in the example shown, the portion 22A closable said portion.

The output closable SA form a closable passage coolant connected to the part so that the closable 22A 22A SA closable passage portion and are traversed by a common flow of coolant when the closable passage SA is not blocked.

The two outputs SA, SB are connected to the first and second circuits 24 26 heat transfer fluid to a common manifold S arranged downstream of the sealing means 36 when considering the flow direction of the heat transfer liquid in the exchanger 22 control fine represented by arrows in Figures 3 and 4.

The closure means 36 are of a conventional type and include, for example, a valve selected from a on-off solenoid valve and a thermostatic valve.

Preferably, control the exchanger 22 is of the plate type.

Specify The below the main aspects of operation of the thermal control device 20 related to the invention.

To cool the intake air at the outlet of the compressor 18, the distribution valve 28 is set so as to connect the inlet control E of the exchanger 22 to the first circuit 24 cold heat transfer liquid. The flow rate of cold heat transfer fluid through the low temperature heat exchanger 30 is set by the pump 32.

Furthermore, the closing valve 36 is opened so that the liquid heat-transfer fluid circulates in the two parts [...], 22B control of the exchanger 22. The cooling liquid flowing in the exchanger 22 cools the intake air by yielding to it frigories.

The circulation of the liquid heat transfer medium in the two parts [...], 22B exchanger 22 provides regulating the heat output required of about 10 to 25 kW for cooling the intake air in the most common conditions.

To heat up the inlet air to, for example, regenerate the particulate filter 19, the distribution valve 28 is set so as to connect the inlet control E of the exchanger 22 the second circuit 26 hot heat-transfer liquid.

Furthermore, the closing valve 36 is closed, so that the coolant liquid flows only in a single exchanger part regulating 22, in other words the portion 22B. Indeed, the single part 22B is sufficient to achieve the required thermal power of about 1 to 3 kW to heat the intake air in the most common conditions.

The liquid coolant circulating in the exchanger portion 22B heats the intake air by yielding to it calories.

When, at the end of a regeneration phase of the particulate filter 19 (air intake heating), requires cooling the intake air, is connected the inlet E control of the exchanger 22 to the first circuit 24 of the heat transfer liquid and is opened the closing valve 36 to replace hot heat transfer liquid circulation in the only portion of the regulating 22B exchanger by a flow of cold heat transfer fluid in the two parts [...], 22B control of the exchanger. This reduces very efficiently the thermal inertia of the exchanger 22 control during the passage of a heating phase of the intake air to a phase for cooling cooling air, relative to a conventional control exchanger all systematically traversed both by the hot heat transfer liquid that by the cold heat transfer liquid.

The invention is not limited to the embodiment described above.

In particular, the use of the device 20 according to the invention is not limited to the temperature control of inlet air into a vehicle engine, the device 20 can be used for temperature regulation of a flow of any air circulating in a motor vehicle.

Furthermore, inversely to what is shown in Figures 3 and 4, the two parts [...], 22B for circulating the heat transfer liquid can be connected to a common output of heat transfer liquid, each part for circulating the heat transfer liquid [...], 22B being connected in this case to a coolant inlet of its own.

Therefore, according to the embodiment selected, the closeable passage may form an outlet or an inlet of the closable 22A portion.

Advantages of the invention, is the following.

The invention provides both cool that heat the intake air for an engine of a vehicle by means of an exchanger dedicated regulating same to these two functions, so that the unit of thermal control is relatively compact and space-saving.

Furthermore, the invention reduces significantly the thermal inertia of the exchanger control during the transition from one phase for heating the intake air to a cooling phase of the intake air.