Variable cooling circuit for thermoelectric generator and engine and method of control

An apparatus comprising:

• an engine;
• an exhaust system operatively connected to the engine and configured to remove exhaust gas from the engine;
• a thermoelectric generator (TEG) operatively connected to the exhaust system and configured to allow exhaust gas flow therethrough;
• a first radiator operatively connected to the engine;
• an openable and closable engine valve configured to open to permit coolant to circulate through the engine and the first radiator when coolant temperature is greater than a predetermined minimum coolant temperature;
• a second radiator;
• a plurality of coolant passages;
• a first valve and a second valve;
• wherein the first valve and the second valve are controllable to selectively establish respective first positions to route coolant flow through some of the coolant passages so that coolant flows from the TEG to the engine and from the engine to the TEG bypassing the second radiator when the engine is operating under a load less than a predetermined minimum load, and controllable to selectively establish respective second positions to route coolant flow through other of the coolant passages so that at least some of the coolant flows from the TEG to the second radiator and from the second radiator to the TEG thereby bypassing the engine and the first radiator when the engine valve is open and the engine is operating under a load not less than the predetermined minimum load.

A method of controlling a cooling circuit in a vehicle having an engine and a thermoelectric generator in an exhaust system, comprising:

• directing coolant from the TEG to the engine and from the engine to the TEG in a first cooling circuit when coolant temperature is below a predetermined temperature and engine load is below a predetermined engine load;
• opening an engine valve to further direct some of the coolant from the engine to a first radiator and from the first radiator to the engine when coolant temperature is above the predetermined temperature;
• directing coolant from the TEG to a second radiator and from the second radiator to the TEG in a second cooling circuit when engine load is above the predetermined engine load;
• and wherein the first cooling circuit bypasses the second radiator and the second cooling circuit bypasses the engine and the first radiator.