Abstract: In a thermal fluid system, a control valve includes a flow valve and a solenoid pilot valve. The flow valve has an inlet and an outlet; a control chamber for receiving a pilot pressure; and a valve member operable by the pilot pressure to selectively open and close a fluid path from the inlet to the outlet. The pilot pressure acts in a closing direction of the flow valve. The pilot valve provides the pilot pressure to the control chamber and is a 3/2 way valve with a first port in fluid communication with the control chamber, a second port to be connected to a pressure source, and a third port. The pilot valve has a first position connecting the first port with the second port and a second position connecting the first port with the third port.

Abstract: In a thermal fluid system, a control valve includes a flow valve and a solenoid pilot valve. The flow valve has an inlet and an outlet; a control chamber for receiving a pilot pressure; and a valve member operable by the pilot pressure to selectively open and close a fluid path from the inlet to the outlet. The pilot pressure acts in a closing direction of the flow valve. The pilot valve provides the pilot pressure to the control chamber and is a 3/2 way valve with a first port in fluid communication with the control chamber, a second port to be connected to a pressure source, and a third port. The pilot valve has a first position connecting the first port with the second port and a second position connecting the first port with the third port.

Abstract: A condensate drainage enhancing device is provided for an evaporator. An integrally molded plastic part snap fits around the conventional lower manifold, with rails maintained in tight engagement with the front and rear edges of the refrigerant flow tubes. These interrupt the meniscus films of columns of retained water that would otherwise form and, which instead drains down ribs that depend from the rails.

Abstract: A heating, ventilation, and air-conditioning (HVAC) system includes a blower, a fresh-air valve, a bypass duct, and a bypass valve. The blower is configured to urge air to flow from an inlet to an outlet of the blower. The fresh-air valve is operable to provide a mixture of air drawn from an outside-air duct and a recirculated-air duct to the inlet. The fresh-air valve is operable to a recirculate position where the outside-air duct is substantially blocked from communicating with the inlet. The bypass duct is configured to couple the outlet to the outside-air duct. The bypass valve is located in the bypass duct and is operable to a closed position and an open position. The cabin is ventilated when the fresh-air valve is in the recirculate position, the bypass valve is in the open position, and the blower is operated to blow air out of the outside-air duct.

Abstract: An automotive evaporator heat exchanger is provided having a hybrid expansion device configured to aliquot refrigerant across the refrigerant tubes. The hybrid expansion device includes a first stage refrigerant pressure drop device and a second stage refrigerant pressure drop device. The first stage refrigerant pressure drop device is a TXV configured to receive and expand a liquid phase refrigerant into a first mixture of two phase refrigerant and the second stage refrigerant pressure drop device is a tube extending within the inlet manifold configured to expand the first mixture of two phase refrigerant into a second mixture of two phase refrigerant. The tube includes a plurality of orifices and a tube diameter large enough to prevent resistance to refrigerant flow, but, small enough to prevent the first mixture of two phase refrigerant flow from separating into liquid and vapor strata.

Abstract: A heating, ventilation, and air-conditioning (HVAC) system includes a blower, a fresh-air valve, a bypass duct, and a bypass valve. The blower is configured to urge air to flow from an inlet to an outlet of the blower. The fresh-air valve is operable to provide a mixture of air drawn from an outside-air duct and a recirculated-air duct to the inlet. The fresh-air valve is operable to a recirculate position where the outside-air duct is substantially blocked from communicating with the inlet. The bypass duct is configured to couple the outlet to the outside-air duct. The bypass valve is located in the bypass duct and is operable to a closed position and an open position. The cabin is ventilated when the fresh-air valve is in the recirculate position, the bypass valve is in the open position, and the blower is operated to blow air out of the outside-air duct.

Abstract: A two-pass evaporator suitable for use in an automobile includes various pressure drop devices to aliquot refrigerant into tubes that make up the two-pass evaporator. The two-pass evaporator includes a first pressure-drop device configured to receive and expand a liquid phase refrigerant into a first mixture of two-phase refrigerant; and a second pressure-drop device configured to receive and expand the first mixture of two-phase refrigerant into a second mixture of two-phase refrigerant and aliquot the second mixture of two-phase refrigerant to the first end of the first plurality of tubes. The two-pass evaporator includes a transition manifold that may house a flow-modulation plate disposed therein and configured to segregate the transition manifold into an upstream portion and a downstream portion. The flow-modulation device works in conjunction with the upstream pressure drop devices to aliquot refrigerant from the first plurality of tubes to the second plurality of tubes.

Abstract: A method of fabricating a folded evaporator tube includes providing a tube with a plurality of webs extending between interior surfaces of the tube. The webs are oriented at an angle between forty-five degrees (45°) and sixty degrees (60°) of angle relative to a bottom wall of the tube. A cutting-device that includes a knife and a guide that cooperate to cut the tube to a desired length is also provided. The knife has a point that is forced in a direction parallel to a wall of the tube. The guide defines an opening that conforms to the tube to maintain the shape of the tube during cutting by the knife. The knife further defines a bottom and top edges that extend away from the point and cooperates with the opening to shear the bottom and top walls of the tube along with internal webs inside the tube.

Abstract: A condensate drainage enhancing device is provided for an evaporator. An integrally molded plastic part snap fits around the conventional lower manifold, with rails maintained in tight engagement with the front and rear edges of the refrigerant flow tubes. These interrupt the meniscus films of columns of retained water that would otherwise form and, which instead drains down ribs that depend from the rails.

Abstract: An automotive evaporator heat exchanger is provided having a hybrid expansion device configured to aliquot refrigerant across the refrigerant tubes. The hybrid expansion device includes a first stage refrigerant pressure drop device and a second stage refrigerant pressure drop device. The first stage refrigerant pressure drop device is a TXV configured to receive and expand a liquid phase refrigerant into a first mixture of two phase refrigerant and the second stage refrigerant pressure drop device is a tube extending within the inlet manifold configured to expand the first mixture of two phase refrigerant into a second mixture of two phase refrigerant. The tube includes a plurality of orifices and a tube diameter large enough to prevent resistance to refrigerant flow, but, small enough to prevent the first mixture of two phase refrigerant flow from separating into liquid and vapor strata.

Abstract: A heat exchanger including a pair of manifolds. An inlet is disposed on one of the ends of the first manifold. A core extends between the manifolds for conveying a coolant therebetween and for transferring heat between the coolant and a stream of air. A cross-over plate is disposed in one of the manifolds to divide the associated one of the manifolds into an upstream section and a downstream section. The cross-over plate presents a plurality of orifices defining a cross-over opening area for establishing fluid communication between the upstream and downstream sections of the associated manifold. The cross-over opening area continuously increases along an axis away from the inlet. The total cross-over opening area is 30% to 300% of the upstream cross-sectional area of the tubes of the core.

Abstract: An evaporator assembly having a first header, a second header, at least two banks of evaporator tubes extending therebetween and in hydraulic communication with the first and second headers. At least one of the evaporator tube may be folded from a unitary strip clad aluminum folded having a thickness (t). The evaporator tube includes a height (h) which is measured from the bottom exterior surface to the top exterior surface, and a corner radius (rc) defined by the transition radius from the flange segments to the channel walls. The bottom wall includes a width (2w), the corrugated portion includes alternating flange segments abutting the interior surface and channel walls connecting the alternating flange segments, at least one of the alternating adjacent flange segments includes a length (a) cooperating with adjacent the channel walls to define a channel having a width (b). The evaporator tube also includes a number of ports per millimeter width (PPMW) in a range of 0.40 to 1.

Abstract: A heat exchanger including a pair of manifolds. An inlet is disposed on one of the ends of the first manifold. A core extends between the manifolds for conveying a coolant therebetween and for transferring heat between the coolant and a stream of air. A cross-over plate is disposed in one of the manifolds to divide the associated one of the manifolds into an upstream section and a downstream section. The cross-over plate presents a plurality of orifices defining a cross-over opening area for establishing fluid communication between the upstream and downstream sections of the associated manifold. The cross-over opening area continuously increases along an axis away from the inlet. The ratio of the total cross-over opening area to the upstream cross-sectional area of the tubes of the core is in the range of XXXXXXXX:XXXXXXX to XXXX:XXXXXX.

Abstract: A heat exchanger including a pair of manifolds. An inlet is disposed on one of the ends of the first manifold. A core extends between the manifolds for conveying a coolant therebetween and for transferring heat between the coolant and a stream of air. A cross-over plate is disposed in one of the manifolds to divide the associated one of the manifolds into an upstream section and a downstream section. The cross-over plate presents a plurality of orifices defining a cross-over opening area for establishing fluid communication between the upstream and downstream sections of the associated manifold. The cross-over opening area continuously increases along an axis away from the inlet. The total cross-over opening area is 30% to 300% of the upstream cross-sectional area of the tubes of the core.