Cooler bypass valve system and method
AssigneeMack Trucks, Inc.
InventorsBrian Tussing, David Britner, Stephen Geyer
Life of this patent
Estimating the term…
Abstract
In preferred embodiments, to, e.g., eliminate condensation build-up in the intake manifold and power cylinders, a charge-air cooler (CAC) and/or EGR cooler “bypass” system is provided that can, e.g., control the intake manifold temperature (IMT) above the dew-point temperature of the boosted air. Preferably, a two-port, single valve-body type valve is provided that proportionally controls the amount of charge-air that is “bypassed” (e.g., not cooled), while simultaneously diverting the charge-air cooler return, preferably, inversely proportionally.
Claims39
A cooler bypass system for use in exhaust gas recirculation, comprising:
- a bypass valve that allows gases to bypass at least one cooler;
- and
- a bypass valve controller that controls said bypass valve to inhibit condensation buildup in an intake manifold or power cylinder by maintaining an intake manifold temperature above the dew-point temperature.
A method of controlling an inlet manifold air temperature to inhibit condensation and the creation of corrosive acids or chemicals, comprising:
- a) providing a bypass valve that allows gases to bypass at least one cooler;
- and
- b) operating said bypass valve to inhibit condensation buildup in an intake manifold or power cylinder by maintaining an intake manifold temperature above the dew-point temperature.
A charge air cooler bypass system, comprising:
- a turbocharger that compresses air before it enters a charge air cooler;
- a charge air cooler that reduces the temperature of the air from the turbocharger before it enters an engine intake;
- and
- a bypass system that mixes higher temperature bypassed air with air from the charge air cooler to create a mixed boost-air temperature that is just above the dew-point temperature so as to inhibit condensation and the formation of acids.
An internal combustion engine having at least one cylinder, an intake, a charge air cooler, and an exhaust gas re-circulator, said charge air cooler providing cooled intake air for delivery into said intake, and said exhaust gas re-circulator for introducing exhaust gas into said intake, comprising:
- a charge air cooler bypass valve for diverting a first mass flow rate of intake air around the charge air cooler and into the intake manifold when said exhaust gas re-circulator is introducing exhaust gas into said intake;
- a charge air cooler throttle valve for reducing a flow of said cooled intake air into the intake manifold from the charge air cooler by a second mass flow rate when said exhaust gas re-circulator is introducing exhaust gas into said intake;
- and
- means for controlling said bypass and throttle valves to cause said intake air diverted around said charge air cooler and said cooled intake air from the charge air cooler to mix to create a mixed boost-air temperature that is just above the dew-point temperature.
An internal combustion engine having at least one cylinder, an intake, a charge air cooler, and an exhaust gas re-circulator, said charge air cooler providing cooled intake air for delivery into said intake, and said exhaust gas re-circulator for introducing exhaust gas into said intake, comprising:
- a charge air cooler bypass valve for diverting a first mass flow rate of intake air around the charge air cooler and into the intake manifold when said exhaust gas re-circulator is introducing exhaust gas into said intake;
- said charge air cooler bypass valve comprising:
- a bypass barrel;
- a bypass shaft intersecting said bypass barrel;
- a bypass plate rotatably connected to said bypass shaft;
- and
- wherein said bypass plate is normally closed;
- a charge air cooler throttle valve for reducing a flow of said cooled intake air into the intake manifold from the charge air cooler by a second mass flow rate when said exhaust gas re-circulator is introducing exhaust gas into said intake;
- said charge air cooler throttle valve comprising:
- a throttle barrel;
- a throttle shaft intersecting said throttle barrel;
- a throttle plate rotatably connected to said throttle shaft;
- and
- wherein said throttle plate is normally open;
- and
- an electronic control unit having a condensation control module adapted to control said bypass valve and said throttle valve so as to create a mixed boost-air temperature with respect to the dew-point temperature to inhibit the formation of condensation and acids.
Dependencies are inferred from the claim text.