Dual pump system and method for cooling an engine of a motor vehicle

An engine cooling system for controlling the temperature of an engine of a motor vehicle, the engine cooling system comprising:

• a fan for creating an airflow;
• an engine cooling circuit for circulating a coolant to transfer heat from the engine to the airflow, the engine cooling circuit comprising:
• an electric water pump configured to draw a maximum current to circulate the coolant through the engine cooling circuit at a maximum electric pump flow rate, wherein the electric water pump comprises one of a brushless DC motor and a brushed DC motor;
• a mechanical water pump configured to circulate the coolant through the engine cooling circuit at a maximum mechanical pump flow rate, wherein the maximum mechanical pump flow rate is higher than the maximum electric pump flow rate;
• a selector valve configured to fluidly connect one of the electric water pump and the mechanical water pump to the engine;
• and
• at least one input sensor configured to measure at least one characteristic of an energy demand on the engine and generate a signal representative of the measured energy demand characteristic;
• and
• an engine control module electrically coupled to the selector valve, the electric water pump, the mechanical water pump, and the at least one input sensor, wherein the engine control module includes a memory that contains energy demand data, wherein the energy demand data is associated with a predetermined flow rate and a predetermined current for the electric water pump;
• wherein the engine control module is configured to:
• compare the energy demand characteristics as measured by the at least one input sensor to the energy demand data for identifying the predetermined flow rate and the predetermined current;
• compare the predetermined flow rate to the maximum electric pump flow rate;
• compare the predetermined current to the maximum current;
• and
• based on the comparisons, generate a valve signal for actuating the selector valve to fluidly connect one of the electric water pump and the mechanical water pump to the engine.

A method for operating an engine cooling system to control the temperature of an engine of a motor vehicle, the engine cooling system including a fan and an engine cooling circuit, where the engine cooling circuit includes an electric water pump configured to draw a maximum current to circulate coolant at a maximum electric pump flow rate, a mechanical water pump configured to circulate coolant at a maximum mechanical pump flow rate that is higher than the maximum electric pump flow rate, and a selector valve, and the engine cooling system further includes at least one input sensor and an engine control module electrically coupled to the electric water pump, the mechanical water pump, the selector valve, and the at least one input sensor, with the engine control module including a memory that contains energy demand data associated with a predetermined flow rate and a predetermined current, the method comprising:

• measuring, using the at least one input sensor, at least one characteristic of an energy demand on the engine;
• generating, using the at least one input sensor, a signal representative of the measured energy demand characteristic;
• comparing, using the engine control module, the energy demand characteristics as measured by the at least one input sensor to the energy demand data to identify the predetermined flow rate and the predetermined current;
• comparing, using the engine control module, the predetermined flow rate to the maximum electric pump flow rate;
• comparing, using the engine control module, the predetermined current to the maximum current;
• and
• based on these comparisons, generating a valve signal for actuating the selector valve to fluidly connect one of the electric water pump and the mechanical water pump to the engine.