METHOD FOR CONTROLLING THERMAL COMFORT AND AIR QUALITY IN THE PASSENGER COMPARTMENT OF MOTOR VEHICLES

Abstract

The invention relates to a method for automatically controlling the closely spaced thermal comfort elements installed in the passenger compartment of motor vehicles as a function of the position of the air intake flaps of the heating, ventilation and air conditioning (HVAC) system equipping these vehicles, characterized in that said thermal comfort elements are activated in cooling mode or in heating mode as a function of the outside temperature and before the flaps are opened. Abstract figure (Fig. 1)

Description

Title of the invention: Method for controlling thermal comfort and air quality in the passenger compartment of motor vehicles

[0001] The invention relates, in general, to the field of motor vehicle ventilation and is more particularly concerned with a method for controlling thermal comfort in the passenger compartment as a function of the outside temperature, the quality of its ambient air and with a view to optimizing electrical consumption.

[0002] Motor vehicles are generally equipped with a heating, ventilation and air conditioning system for the passenger compartment (also called HVAC for "Heating, Ventilation and Air-Conditioning") comprising a module for controlling the incoming air flow. Depending on the type of vehicle, this module is supplied by air inlets whose flow is regulated by flaps and distributed in a distributed manner in the passenger compartment between several channels.

[0003] This system generally allows an operating mode ensuring both recycling and regeneration of the air in the passenger compartment. Currently, for 80% of its operating time, the air intake flap of the module is in a fully or partially open position, if only to manage the relative humidity and eliminate the fog appearing on the windshield which reduces the driver's visibility.

[0004] However, in order to optimize the electrical consumption of vehicles, in particular that of electric vehicles which do not benefit from the heat input of the thermal engine, the objective is to activate in the future the HVAC system for 90% of its operating time in total recycling mode.

[0005] In addition, existing vehicles are also equipped with so-called "close-coupled" comfort elements, heated or cooled, which complement the functions of the HVAC system. These include, for example, a heated steering wheel, heated, ventilated and / or cooled seats, heated headrests, heated / cooled trim panels, positioned at different locations in the passenger compartment, etc.

[0006] These comfort elements, which also contribute to the thermal comfort of the passenger compartment, help to reduce the amount of electrical energy consumed by the HVAC system alone. Consequently, the overall electrical energy consumption of the vehicle is reduced, which, for electrically powered vehicles, makes it possible to advantageously increase their autonomy.

[0007] Furthermore, the performance of acoustic filtration means has improved considerably in recent years. However, these means include numerous insulating seals, mounted mainly around the openings, which today make vehicles "tight" to noise but also to air.

[0008] Under these conditions, the objective of optimizing the electrical consumption of vehicles by fine control of the air intake flap of the HVAC system, in particular by increasing the operating time in total recycling mode with the flaps closed, has the direct consequence of raising the CO2 concentration in the passenger compartment to reach values which may prove dangerous for human health.

[0009] Thus, it has been demonstrated experimentally that in a vehicle passenger compartment where two people are seated, with an HVAC system in total air recirculation mode (air intake flaps closed), the CO2 concentration increases from 1000 to 5000 ppm in 16 minutes. This phenomenon is even stronger when the number of passengers increases.

[0010] However, it is accepted that a concentration of 1000 to 2000 ppm of CO2 in the air already causes a feeling of numbness in humans and that from 2000 to 5000 ppm of CO2, the air becoming stale, causes headaches, a drowsy effect, difficulty concentrating leading to a loss of attention, an acceleration of the heart rate and slight nausea. All these harmful effects affect driving safety and also directly impact the health of passengers (according to WHO standards).

[0011] Patent application JP2009280017A describes an input regulation system outside air depending on the CO2 level both in the outside atmosphere and in the passenger compartment.

[0012] However, this system is not concerned with the piloting and control of nearby thermal comfort elements which would complement the HACV system, nor consequently, with their possible influence on the electrical consumption of the vehicle.

[0013] In this context, the invention consisted of developing a method for automatically controlling the comfort elements close together as a function of the position of the air intake flap of the HVAC system to limit the discomfort resulting in the passenger compartment from air that is too hot or too cold depending on the outside environment while seeking, at the same time, to preserve the health of the occupants and to optimize the electrical consumption of the vehicle.

[0014] This object is achieved, according to the invention, by means of a method for automatically controlling the closely spaced thermal comfort elements installed in the passenger compartment of motor vehicles as a function of the position of the air intake flaps of the heating, ventilation and air conditioning (HVAC) system equipping these vehicles, characterized in that said thermal comfort elements are activated in cooling mode or in heating mode as a function of the outside temperature and before the flaps are opened.

[0015] According to an advantageous characteristic of implementing the method of the invention, an emergency opening of the flaps is activated when the CO2 concentration in the passenger compartment reaches a predetermined value.

[0016] According to an additional characteristic of the method of the invention, an emergency opening of the shutters is activated when the windows of the passenger compartment are fogged up.

[0017] According to a further specific characteristic of implementation of the method of the invention, an emergency closing of the shutters is activated when the concentration of pollutants in the outside air reaches a predetermined value.

[0018] Preferably, the thermal comfort elements are activated in cooling mode if the outside temperature is between 19.5°C and 25.5°C in heating mode if the outside temperature is between 12°C and 18°C while keeping the shutters closed to ensure total recycling of the ambient air.

[0019] Where appropriate, from an outside temperature of 25°C with sunshine, the air conditioning system and / or the nearby thermal comfort elements are activated.

[0020] According to an alternative implementation of the method of the invention, the heating of the thermal comfort elements is increased when the shutters are in the partially open position and the outside temperature is between 9.5°C and 15.5°C.

[0021] According to another variant of implementation of the method of the invention, the cooling of the thermal comfort elements is more or less forced when the shutters are in the partially open position and the outside temperature is between 22°C and 28°C.

[0022] Another object of the invention is a heating, ventilation and air conditioning (HVAC) system for the passenger compartment of motor vehicles equipped with closely spaced thermal comfort elements, characterized in that it further comprises CO2 sensors, interior and exterior temperature sensors, an on-board computer and software for implementing the method as defined above.

[0023] Yet another object of the invention is a motor vehicle equipped with a heating, ventilation and air conditioning (HVAC) system of the above type.

[0024] In its most general aspect, the control method of the invention consists of adopting, automatically and in anticipation, an operating mode of the close comfort elements as a function of the future position of the air inlet flaps of the HVAC system.

[0025] By anticipating the partial or total opening of the air intake flaps, the method of the invention thus makes it possible to improve the comfort of the passenger compartment which may be degraded due to air that is too hot or too cold depending on the temperature of the outside environment. Indeed, the various changes in position of the air intake flaps which are unwanted are likely to create inconvenience for the vehicle occupants.

[0026] Furthermore, the method of the invention makes it possible to optimize the electrical consumption of the vehicle.

[0027] Furthermore, the detection of CO2 in the passenger compartment by means of appropriate sensors has become essential in the case of air conditioning systems using this gas to replace refrigerant fluids of the R1234yf type. Indeed, the regulations are in the process of banning these fluids which were still used until today to provide air conditioning for most private vehicles.

[0028] The method of the invention also provides for the emission of alerts in the event of a CO2 leak in the passenger compartment when the air conditioning system uses this gas in order to protect the health of the occupants. Indeed, the operation of the shutters in total recycling mode (shutters closed) can cause an increase in the concentration of CO2 in the passenger compartment.

[0029] The same applies when the vehicle passes through a tunnel or a traffic jam where there is a significant risk of an increase in the concentration of CO2 or pollutants.

[0030] Other characteristics and advantages of the invention will emerge on reading the description which follows, with reference to the appended figure.

[0031] [Fig. 1] is a block diagram illustrating a preferred mode of implementation of the method of the invention for controlling closely spaced thermal comfort elements.

[0032] The method of the invention relates to the automatic control of so-called "close" thermal comfort elements. These elements, which equip the passenger compartment of certain motor vehicles, have a heating and / or cooling function for various components of the passenger compartment, such as the steering wheel, the seats and armrests, the headrests and, where appropriate, various interior trim panels. These thermal comfort elements complement the functions of the heating, ventilation and air conditioning (HVAC) system.

[0033] The method of the invention aims to adopt, in anticipation and automatically, an operating mode, in heating or cooling, possibly progressive, of the comfort elements close together according to the predictable position of the air inlet flaps of the HVAC system.

[0034] Indeed, the comfort of the passenger compartment may be degraded, independently of the wishes of the occupants, due to a flow of air entering the passenger compartment, due to a partial or total opening of the shutters, and the temperature of which is too hot or too cold depending on the temperature of the outside environment.

[0035] Furthermore, the complete closure of the shutters certainly allows the recycling of ambient air, but leads to an increase in the CO2 concentration in the passenger compartment and to polluting the ambient air, even in the case of filtration.

[0036] An example of implementation of the method of the invention is described below and illustrated by [Fig.l].

[0037] When the outside temperature is hot (above 27.5°C), or even very hot (above 32.5°C), the flaps of the ventilation system are closed to recycle the air but will tend to open to renew the air in the passenger compartment and evacuate the CO2. However, the temperature in the passenger compartment then risks rising and generating discomfort for the occupants. The method of the invention then provides for activating the cooling of all or part of the comfort elements close together before the flaps are opened. The cooling of these elements (possibly progressive then forced up to 28°C), will make it possible to lower the temperature to approximately 25°C in the passenger compartment so as to smooth out the feeling of comfort when the flaps are next opened.

[0038] Conversely, when the outside temperature is cold (below 12.5°C), or even very cold (below 7°C), the flaps of the ventilation system are closed but will tend to open to, jointly, renew the air in the passenger compartment, ensure the demisting of the windshield and windows by managing a relative humidity (RH) level that is too high and evacuate the CO2. Under these conditions, the temperature in the passenger compartment then risks dropping and generating discomfort for the occupants. The method of the invention then provides for activating the heating of all or part of the comfort elements close together before the flaps are opened. Activating the heating of these elements (possibly progressive and pushed up to 80°C), will allow the temperature in the passenger compartment to be raised gradually between 12.5°C and 27.5°C and to stabilize it, preferably, at around 25°C so as to smooth out the feeling of comfort when the shutters are subsequently opened.

Claims

Claims

1. Method for automatically controlling the closely spaced thermal comfort elements installed in the passenger compartment of motor vehicles as a function of the position of the air intake flaps of the heating, ventilation and air conditioning (HVAC) system equipping these vehicles, characterized in that said thermal comfort elements are activated in cooling mode or in heating mode as a function of the outside temperature and before the flaps are opened.

2. Method according to claim 1, characterized in that an emergency opening of the shutters is activated when the CO2 concentration in the passenger compartment reaches a predetermined value.

3. Method according to one of the preceding claims, characterized in that an emergency opening of the shutters is activated when the windows of the passenger compartment are fogged up.

4. Method according to one of the preceding claims, characterized in that an emergency closing of the shutters is activated when the concentration of pollutants in the outside air reaches a predetermined value.

5. Method according to one of the preceding claims, characterized in that said thermal comfort elements are activated in cooling mode if the outside temperature is between 19.5°C and 25.5°C in heating mode if the outside temperature is between 12°C and 18°C while keeping the shutters closed to ensure total recycling of the ambient air.

6. Method according to the preceding claim, characterized in that from an outside temperature of 25°C with sunshine, the air conditioning system and / or the nearby thermal comfort elements are activated.

7. Method according to one of the preceding claims, characterized in that the heating of the thermal comfort elements is pushed when the shutters are in the partially open position and the outside temperature is between 9.5°C and 15.5°C.

8. Method according to one of the preceding claims, characterized in that the cooling of the thermal comfort elements is more or less forced when the shutters are in the partially open position and the outside temperature is between 22°C and 28°C.

9. Heating, ventilation and air conditioning (HVAC) system for the passenger compartment of motor vehicles equipped with closely spaced thermal comfort elements, characterized in that it comprises CO2 sensors, interior and exterior temperature sensors, an on-board computer and software for implementing the method according to one of the preceding claims.

10. A motor vehicle equipped with a heating, ventilation and air conditioning (HVAC) system according to the preceding claim.

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