generally in a steady state and the coolant temperature may not significantly deviate the normal operating temperature t 0 in an automotive vehicle this may correspond to cruising conditions deceleration or engine at idle during this state the auxiliary valve 44 is arranged to pass all of the coolant flowing through the radiator outlet line 92 directly to the water pump 66 while inhibiting the flow of coolant though the bypass line 42 and the accumulator 90 if the accumulator 90 is be exposed to ambient air its temperature may be near the ambient air temperature when on the other hand the waste heat load exceeds the heat transfer capacity of the radiator 72 the coolant temperature may begin to rise in an automotive vehicle this may correspond to a vehicle accelerating or hill climbing when the coolant temperature rises above the threshold temperature t thresh the auxiliary valve 44 is arranged to direct a substantial portion of the coolant flowing through the radiator outlet line 92 into the auxiliary line 42 and through the accumulator 90 as a result a substantial portion of the heat in the coolant is transferred to the accumulator 90 and at least in part stored therein as sensible heat when in addition the temperature of the coolant entering the heat accumulator 90 significantly exceeds the temperature t melt the pcm 126 inside the accumulator 90 may begin to melt thereby absorbing additional heat from the coolant as a result the temperature of the coolant exiting the accumulator.