摘要 |
An engine cooling system has a primary cooling circuit having with a coolant pump to pump coolant to the engine, an engine return line, a radiator and a bypass in parallel with the radiator. The primary circuit also has a flow control valve to control flow between the radiator and the bypass to allow fluid to flow from the radiator only when coolant temperature is above normal operating temperature. The system also has a secondary cooling circuit with a heat exchanger and a temperature responsive control valve and a heater circuit connected to a passenger compartment heater. The temperature responsive conrol valve shuts off flow through both or one of the inlets depending on coolant temperature. |