Patent Application
20220055444
The present invention generally relates to a Heating Ventilation and Air-Conditioning (HVAC) system, more particularly, to a Recirculation Air Management (RAM) in the HVAC system.
Generally, Heating Ventilation and Air-Conditioning (HVAC) systems are installed in a vehicle to provide comfort driving to driver and passengers. The HVAC system either provides hot or cold air to the passenger's cabin depending on the selected mode. Further, the HVAC system is defined with two modes such as a fresh air mode, and a recirculation air mode. In the fresh air mode, the HVAC housing may receive ambient air from the atmospheric through a fresh air inlet. In the recirculation air mode, the air being recirculated from the passenger's cabin to the HVAC housing through a recirculation air inlet. The recirculation air mode is provided in the HVAC to reduce energy consumption of the HVAC. For example, while the vehicle in colder region, the fresh air is very cold, so that the HVAC may consume more energy to provide hot air to the passenger's cabin. In such cases, the recirculated air is provided back to the HVAC that have higher temperature than of the fresh air, so the HVAC may consumes may less energy than the HVAC operating in the fresh air mode. However, there is a problem while using the HVAC in the recirculation mode, which is frosting in doors and windshields due to the humidity content in the recirculation air. Normally, the recirculated air contains humidity due to presence of passengers, so doors and windshields are frosted and affects visibility of the road. To avoid such phenomenon, a partial recirculation air mode is provided in the HVAC system. In such mode, the fresh air inlet and the recirculation air inlet are partially opened to mix the fresh air with the recirculation air in the HVAC, so possibly avoiding frosting of the doors and windshields. However, in such partial recirculation air mode, there is a possibility of flowing the fresh air into the recirculation outlet, which affect performance of the HVAC and invite the above-mentioned problems.
Accordingly, there remains a need for a smart HVAC system that avoid frosting issues while the HVAC system operates in the recirculation air mode. Further, there remains a need for a Recirculation Air Management (RAM) for a HVAC system.
In the present description, some elements or parameters may be indexed, such as a first element and a second element. In this case, unless stated otherwise, this indexation is only meant to differentiate and name elements which are similar but not identical. No idea of priority should be inferred from such indexation, as these terms may be switched without betraying the invention. Additionally, this indexation does not imply any order in mounting or use of the elements of the invention.
In view of the foregoing, an embodiment of the invention herein provides a Heating, Ventilation, and Air-Conditioning unit for a vehicle. The HVAC unit comprises a housing, a first inlet, a second inlet, at least one first flap, and a third door. The first inlet is provided in the housing for enabling a first airflow into the housing. The second inlet is provided in the housing for enabling a second airflow into the housing. The at least one first flap having a first door and a second door, attached to the first inlet. The first door is angularly movable with respect to the second door and adapted to move between a first position and a second position to open and close the first inlet. Further, the second door is angularly movable with respect to the first door and adapted to move between the first position and a third position to open and close air passage between the first inlet and the second inlet. The at least one third door rotatably connected in the second inlet. Further, the at least one third door is movable between a closed position where the second inlet is closed and at least partially open position where the second inlet is partially open.
In one embodiment, the first door and the second door are barrel doors that have a same axis of rotation.
In another embodiment, the at least one third door is a butterfly door.
Further, the movement of the at least one third door is based on humidity level of passenger's cabin of the vehicle.
Further, the first door of the at least one first flap is in the second position and the at least one third door is in the open position when the Heating, Ventilation, and Air-Conditioning unit defining a recirculation air mode.
Further, the first door of the at least one first flap is in the first position and the at last one third door is in the closed position when the Heating, Ventilation, and Air-Conditioning unit defining a fresh air mode.
Further, the first door of at least one first flap is in the first position, the second door of the at least one first flap is in the third position and the at least one third door is in partially open position when the Heating, Ventilation, and Air-Conditioning unit defining a partial-recirculation air mode.
In one embodiment, the first door and the second door of the at least one first flap are overlap with each other when the both first door and the second door of the at least one first flap is in the first position.
In another embodiment, the angular movement of the at least one first flap is based on a temperature of the atmospheric air.
Further, the second inlet is juxtaposed to the first inlet.
Further, the HVAC unit comprising a blower adapted to receive air from at least one of the first inlet and the second inlet, a humidity sensor adapted to measure humidity level of the vehicle compartment, and a temperature sensor adapted to measure temperature of the atmospheric air.
Furthermore, the HVAC unit comprising an electronic control unit adapted to receive the humidity and temperature from the respective humidity sensor and temperature sensor and dynamically control the at least one first flap and the at least one third door.
Other characteristics, details and advantages of the invention can be inferred from the description of the invention hereunder. A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying figures, wherein:
It must be noted that the figures disclose the invention in a detailed enough way to be implemented, the figures helping to better define the invention if needs be. The invention should however not be limited to the embodiment disclosed in the description.
The present invention relates to a Heating, Ventilation, Air-conditioning (HVAC) system, hereinafter referred to as HVAC system, for a vehicle. The HVAC system may be provided for the recirculation air management (RAM). The HVAC system may operate in three modes, such as a fresh air mode, a recirculation air mode, and a partial-recirculation air mode. To avoid frosting of windshields and doors of the vehicle during the recirculation air mode, the partial-recirculation air mode is provided in the HVAC system. As a fresh air inlet and a recirculation air inlet are in open position during the partial-recirculation air mode, there is a possibility that the fresh air from the fresh air inlet can directly flow back into the recirculation air inlet due to the pressure difference between the fresh air and the recirculation air. To avoid such scenario, a fresh air inlet flap and a recirculation air inlet door are designed in such a way that the fresh air inlet flap block an air passage between the fresh air inlet and the recirculation air inlet during the HVAC operating in the partial-recirculation air mode.
In this example, the second door 108A is angularly movable between the first position 112 and a third position 116 to open and close the air passage between the first inlet 104 and the second inlet 106 respectively. In first position 112, the second door 108B may allow any airflow between the first inlet 104 and the second inlet 106, whereas, the second door 108B may block an airflow between the first inlet 104 and the second inlet 106 when the second door 108B is in the third position 116. Although the second door 108B moves between the first position 112 and the third position 116 to open and close the air passage, it is possible to position the second door 108B in between the first position 112 and the third position 114 to partially close the air passage between the first inlet 104 and the second inlet 106. In one embodiment, the first door 108A and the second door 108B are barrel doors having a same axis of rotation.
The HVAC unit 100 further includes a third door 110 rotatably connected to the second inlet 106 defined in the housing 102. The third door 110 is adapted to control the second airflow flowing from the second inlet 106. The third door 110 is adapted to close the second inlet 106, and partially open the second inlet 106. Further, it is possible for the third door 110 to open the second inlet 106 completely to allow the second airflow into the housing 102. In one embodiment, the third door 110 is a butterfly door, which is angularly movable to control the second airflow to the housing 102. In one example, movement of the third door 110 is based on humidity level of the passenger's cabin of the vehicle. The HVAC unit 100 further includes a filter 118 and a blower 120 provided in a downstream to the first inlet 104 and the second inlet 106. The filter 118 is provided in between the blower 120 and the first and second inlets 104, 106 to filter the airflow received from the first inlet 104 and the second inlet 106. The blower 120 is adapted to draw mixed air of the first and second airflow and provides to other elements such as an evaporator or a heating element depending on requirement of the passenger.
Further, the HVAC unit 100 may operate in three different modes, such as a fresh air mode, a recirculation air mode, and a partial-recirculation air mode. Generally, while providing cooling function to the passenger cabin, the fresh air mode is energy efficient, whereas the recirculation air mode is energy efficient when the HVAC unit 100 provide heating function to the passenger's cabin. However, to avoid any frosting on the windshields and windows glasses formed due to humidity of the recirculation air, a partial-recirculation air mode is introduced in the HVAC unit 100. In the partial-recirculation air mode, the first inlet 104 and the second inlet 106 are partially open to optimally mix the first airflow and the second airflow, so that frosting of the windows and windshields can be avoided and meantime energy consumption by the HVAC unit 100 is reduced. The first flap 108 and the third door 110 may operate based on temperature of ambient air and humidity level inside the vehicle. The HVAC unit may include a humidity sensor or any other means provided in the passenger's cabin to measure the humidity level of the cabin and provide a signal to an ECU (Electronic Control Unit). Further, a temperature sensor may be provided outer side of the vehicle and exposed to the ambient air to measure temperature of the ambient air and provide a signal to the ECU. The ECU may control the first door 108A, the second door 108B, and the third door 110 based on the signals from the temperature sensor and humidity sensor. Different mode of operation of the HVAC unit 100 is explained with forthcoming figures.
In any case, the invention cannot and should not be limited to the embodiments specifically described in this document, as other embodiments might exist. The invention shall spread to any equivalent means and any technically operating combination of means.
All the above-described embodiments are just to explain the present invention while more embodiments and combinations thereof might exist. Hence, the present invention should not be limited to the above-described embodiments alone.
