CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2018-0161156 filed on Dec. 13, 2018, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a system for controlling inside/outside air in an air conditioner. More particularly, it relates to a system for controlling inside/outside air in an air conditioner for maximizing a heating effect of a vehicle interior without fogging on a vehicle glass.

Description of Related Art

A vehicle is provided with an air conditioning system for controlling indoor temperature and ventilation (hereinafter, referred to as an “air conditioner”), and the air conditioner is also called a heating, ventilation, and air conditioning system (HVAC).

In general, the air conditioner heats or cools outdoor air (outside air) introduced from the outside of the vehicle or indoor air (inside air) circulated in the interior of the vehicle and supplies the heated and cooled air to the interior to heat or cool the interior of the vehicle.

Such an air conditioner utilizes engine coolant as a heat source for heating air. However, the engine heat quantity is reduced and the temperature of the engine coolant used as a main heat source for heating the vehicle interior is lowered as techniques for increasing engine efficiency have been applied in recent years. As a result, it is difficult to secure the heating effect of the vehicle interior using the engine coolant, which causes a problem relating to deterioration in the heating performance of the vehicle interior.

The information included in this Background of the present invention section is only for enhancement of understanding of the general background of the present invention and may not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing a system for controlling inside/outside air in an air conditioner, configured for enhancing indoor heating performance by increasing a maximum amount of inside air circulated through an air conditioner without fogging on a windshield glass in front of a vehicle to reduce heat loss due to introduction of outside air for ventilation.

In an exemplary embodiment of the present invention, there is provided a system for controlling inside/outside air in an air conditioner, which includes an air conditioner including an upward discharge passage, through which air is discharged toward a front glass of a vehicle, a downward discharge passage, through which air is discharged toward a floor of the vehicle, the upward discharge passage and the downward discharge passage being separated from each other, a first intake door, an opening amount of which is determined according to a ratio between inside air and outside air introduced into the upward discharge passage, and a second intake door, an opening amount of which is determined according to a ratio between inside air and outside air introduced into the downward discharge passage, and a control unit configured of controlling the opening amounts of the first and second intake doors according to a heating load of the air conditioner and a humidity of the interior of the vehicle.

The upward discharge passage may be configured such that only outside air is introduced when the first intake door is fully open and only inside air is introduced when the first intake door is fully closed, and the downward discharge passage may be configured such that only inside air is introduced when the second intake door is fully open and only outside air is introduced when the second intake door is fully closed. Furthermore, outside air and inside air may be simultaneously introduced into the upward discharge passage when the first intake door is partially open, and outside air and inside air may be simultaneously introduced into the downward discharge passage when the second intake door is partially open in a state in which the first intake door is at least partially open.

When the heating load of the air conditioner is equal to or greater than a reference load and the humidity of the vehicle interior is less than or equal to a reference humidity, the control unit may allow the first and second intake doors to be fully open, and then periodically control the opening amounts of the first and second intake doors based on a fog risk level according to the humidity of the vehicle interior. The fog risk level may be divided into a plurality of levels based on the internal humidity value, and the control unit may reduce the opening amount of the first intake door and maintain the opening amount of the second intake door when it is determined that it is possible to reduce the opening amount of the first intake door based on the fog risk level. The control unit may determine that it is possible to reduce the opening amount of the first intake door when it is determined that the fog risk level is lower than a set reference level.

The control unit may reduce the opening amount of the second intake door and maintain the opening amount of the first intake door when it is determined that it is necessary to reduce the opening amount of the second intake door based on the fog risk level in a state in which the first intake door is fully open. The control unit may determine that it is necessary to reduce the opening amount of the second intake door when it is determined that the fog risk level is higher than a set reference level in a state in which the first intake door is fully open.

The control unit may maintain the opening amount of the first intake door when it is determined that it is unnecessary to change the opening amount of the first intake door based on the fog risk level, and maintain the opening amount of the second intake door when it is determined that it is unnecessary to change the opening amount of the second intake door based on the fog risk level.

The control unit may allow the first intake door to be open by a predetermined amount and allow the second intake door to be maintained in a fully open state when the fog risk level is a set minimum level, and may allow the first intake door to be maintained in a fully open state and allow the second intake door to be fully closed when the fog risk level is a set maximum level.

The control unit may allow the first intake door to be fully open and allow the second intake door to be fully closed when the heating load of the air conditioner is less than the reference load or the humidity of the vehicle interior exceeds the reference humidity.

The heating load of the air conditioner may be determined based on a vehicle external temperature, a blower rotation speed of the air conditioner, and an engine coolant temperature. The humidity of the vehicle interior may be a relative humidity value measured by a humidity sensor mounted on the front glass in front of the vehicle. The air conditioner may include a heating unit of heating air introduced into the upward discharge passage and the downward discharge passage, and the heating unit may heat the air according to the heating load.

In another exemplary embodiment of the present invention, there is provided a system for controlling inside/outside air in an air conditioner, which includes an air conditioner including an upward discharge passage, through which air is discharged toward a front glass of a vehicle, a downward discharge passage, through which air is discharged toward a floor of the vehicle, the upward discharge passage and the downward discharge passage being separated from each other, a first intake door, an opening amount of which is determined according to a ratio between inside air and outside air introduced into the upward discharge passage, and a second intake door, an opening amount of which is determined according to a ratio between inside air and outside air introduced into the downward discharge passage, and a control unit configured of controlling the opening amounts of the first and second intake doors according to a heating load of the air conditioner.

The upward discharge passage may be configured such that only outside air is introduced when the first intake door is fully open and only inside air is introduced when the first intake door is fully closed, and the downward discharge passage may be configured such that only inside air is introduced when the second intake door is fully open and only outside air is introduced when the second intake door is fully closed. Furthermore, outside air and inside air may be simultaneously introduced into the upward discharge passage when the first intake door is partially open, and outside air and inside air may be simultaneously introduced into the downward discharge passage when the second intake door is partially open in a state in which the first intake door is at least partially open.

The control unit may allow the first and second intake doors to be fully open when the heating load of the air conditioner is equal to or greater than a first load value and less than a second load value. The control unit may allow the first intake door to be open by a certain amount and allow the second intake door to be fully open when the heating load of the air conditioner is equal to or greater than a second load value which is higher than a first load value. The control unit may allow the first intake door to be fully open and allow the second intake door to be fully closed when the heating load of the air conditioner is less than a first load value.

Other aspects and exemplary embodiments of the present invention are discussed infra.

It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger vehicles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

The above and other features of the present invention are discussed infra.

