HVAC MODULE WITH ANTI-BACKFLOW CONTROL AND METHOD OF OPERATION

摘要

HVAC module has an air inlet, an evaporator downstream of the blower and a heater downstream of the evaporator, and a rear mixing zone downstream of the evaporator and the heater, wherein a control valve prevents cold air from flowing back towards the hot air by regulating the pressure of the cold air. A method is devised to control anti-backflow control valve of such an HVAC module by the steps of reading pressure and temperatures at various points in the HVAC module; setting air flow and temperature discharge targets; calculating the resistance of the control valve and a bland valve; determining corresponding control valve and blend valve positions; and moving the control valve and blend valve to those corresponding positions.

主权项

1. An HVAC module, comprising:
a housing defining an air inlet, a front zone air outlet, and a rear zone air outlet; an evaporator disposed within the housing downstream of the air inlet; a heater disposed within the housing downstream of the evaporator; a cold air chamber downstream of the evaporator defined in the housing between the evaporator and the heater, the cold air chamber having a first pressure; a hot air chamber downstream of the heater defined in the housing between the heater and a first interior surface of the housing, the hot air chamber having a second pressure quantitatively lower than the first pressure of the cold air chamber, the hot air chamber being in fluid communication with a rear zone mixing chamber defined by the housing, the rear zone mixing chamber having a third pressure and being in fluid communication with the rear zone air outlet; a cold air stream path defined by a second interior surface of the housing and an interior partition in the housing, the cold air stream path extending from the cold air chamber to the rear zone mixing chamber; and a control valve disposed in the housing between the cold air chamber and the rear zone mixing camber, the control valve configured to selectively control a release of cold air from the cold air chamber along the cold air stream path into the rear zone mixing chamber so as to control backflow of cold air into the hot chamber.