Systems and methods for regulating engine coolant flow to control engine temperature and fuel temperature

A method of controlling thermal management in an internal combustion engine system having an evaporator, a coolant pump, a bypass valve, and a radiator, the method comprising:

• supplying hot engine coolant from an internal combustion engine to the evaporator;
• transferring heat from the hot engine coolant to ammonia in the evaporator to produce cooled engine coolant;
• supplying the cooled engine coolant from the evaporator to the coolant pump;
• controlling a flow rate of the coolant pump based on one or more sensed temperatures including at least one of engine temperature and fuel temperature;
• and
• routing the cooled engine coolant from the coolant pump to the bypass valve and selectively directing, with the bypass valve, the cooled engine coolant either to the radiator or to the internal combustion engine.

A thermal management system for an internal combustion engine, comprising:

• an evaporator;
• a coolant pump;
• a bypass valve fluidly coupled downstream of the dedicated coolant pump;
• a radiator fluidly coupled to the bypass valve;
• an engine coolant supply line configured to carry hot engine coolant from the internal combustion engine to the evaporator;
• a first coolant line configured to carry cooled engine coolant from the evaporator to the coolant pump;
• a second coolant line configured to carry the cooled engine coolant from the coolant pump to the bypass valve;
• a third coolant line configured to carry cooled engine coolant from the bypass valve to the radiator;
• a fourth coolant line configured to carry cooled engine coolant from the bypass valve to the internal combustion engine;
• and
• an electronic control unit configured to vary a flow rate of the coolant pump based on one or more sensed temperatures including at least one of engine temperature and fuel temperature.