A thermal storage battery consists of 10 kg of a salt solution that changes phase at 80°C and has the following properties:                     The battery container is super insulated with a heat...

A thermal storage battery consists of 10 kg of a salt solution that changes phase at 80°C and has the following properties:

The battery container is super insulated with a heat loss rate of 3 W (assume constant). Engine coolant flows through the battery at a rate of 0.09 kg/sec, and has a temperature of 110°C when the engine is running. Coolant can be approximated as water.

Calculate:

(a) How long it takes for the battery solution to reach 80°C after the engine is turned off. [hr]

(b) How long the battery solution remains at 80°C as it changes phase. [hr]

(c) How long until the battery cools to an ambient temperature of 10°C. [hr]

(d) How long the battery can supply coolant at 80°C when the engine is started at a temperature of 20°C. Assume the battery solution starts as all liquid at 80°C, and the engine coolant enters at 20°C and leaves at 80°C. [min.