A 2000-liter water tank can withstand pressures up to 20.0bar absolute before rupturing. At a particular time the tank contains 165.0 kg of liquid water, the fill and exit valves are closed, and the absolute pressure in the vapor head space above the liquid (which may be assumed to contain only water vapor) is 3.0bar. A plant technician turns on the tank heater, intending to raise the water temperature to 155°C, but is called away and forgets to return and shut off the heater. Let t1 be the instant the heater is turned on and t2 the moment before the tank ruptures. Use the steam tables for the following calculations.

(a) Determine the water temperature, the liquid and head-space volumes (L), and the mass of water vapor in the head space (kg) at time r.

(b) Determine the water temperature, the liquid and head-space volumes (L), and the mass of water vapor (g) that evaporates between t1 and t2.

(c) Calculate the amount of heat (kJ) transferred to the tank contents between t1 and t2. Give two reasons why the actual heat input to the tank must have been greater than the calculated value.

(d) List three different factors responsible for the increase in pressure resulting from the transfer of heat to the tank.

(e) List ways in which this accident could have been avoided.