Cooling system with boiling prevention

A cooling system for use with an internal combustion engine comprising:

• a heat exchanger comprising a hot-side inlet, a hot-side outlet, and one or more hot-side passages extending therebetween, wherein the hot-side inlet is in gas flow communication with an exhaust gas stream exiting the engine, the heat exchanger further comprising a cold-side inlet and a cold side outlet, wherein the cold side inlet is in fluid flow communication with a source of cooling medium, wherein the cooling medium passes into the heat exchanger and makes contact with the hot-side passages as the cooling medium is passed from the cold-side inlet to the cold-side outlet through at least one cold-side passage;
• an exhaust gas bypass valve that is positioned adjacent the heat exchanger hot side inlet and is controlled by an actuator to regulate the flow of exhaust gas to the heat exchanger;
• a means for sensing the condition of the cooling medium within the heat exchanger;
• and
• a controller for receiving input from the means for sensing and determining whether the cooling medium is in a boiling state by comparing a stored value within said controller with said received input from said means for sensing and for controlling the actuator operating the bypass valve to adjust the amount of exhaust gas directed to the hot-side passages of the heat exchanger based upon said determination of the boiling state of the cooling medium so that the cooling medium within the heat exchanger is not in a boiling state, said bypass valve increasing the amount of bypass of the exhaust gas stream exiting the engine around the hot-side passages upon determining a boiling state of the cooling medium in said at least one cold-side passage by a set amount and duration sufficient to remove the cooling medium from the boiling state.

A method for controlling the condition of a cooling medium disposed within a cooler used with an internal combustion engine, the cooler comprising a hot-side inlet and hot-side outlet with one or more hot-side passages extending therebetween, and a cold-side inlet and cold-side outlet for accommodating the passage of the cooling medium within the cooler along a surface of the hot-side passages to reduce the temperature of a hot-side gas or liquid as it passes through the cooler, the method comprising the steps of:

• sensing the condition of the cooler with at least one of a cooling medium temperature sensor, cooling medium pressure sensor, or hot-side outlet temperature sensor;
• evaluating the condition of the cooling medium to determine whether it is in an undesired boiling state, said evaluating being selected from the group consisting of comparing a sensed temperature of the cooling medium with a boiling temperature of the cooling medium, comparing a sensed pressure of the cooling medium with a vapor pressure of the cooling medium in the cooler, monitoring an increase in a sensed temperature of the hot-side outlet, monitoring sensed cooling medium temperature as a function of sensed cooling medium pressure and determining if a saturation temperature of the cooling medium has been reached and combinations thereof;
• and
• adjusting one or more of the amount of hot-side gas or liquid entering the cooler decreasing the amount of hot-side gas or liquid flowing through the hot-side passages, the amount of cooling medium entering the cooler with a valve controlling the introduction of additional cooling medium about an outer surface of the hot-side passages, the flow direction of the cooling medium within the cooler toward the hot-side inlet, and one or more operating conditions of the engine based upon said evaluated condition of said cooling medium to ensure that the condition of the cooling medium is not in the undesired boiling state.