Cold water with an enthalpy of \(8 \mathrm{Btu} / \mathrm{lbm}\) enters a heater at the rate of \(5 \mathrm{lbm} / \mathrm{sec}\) with a velocity of \(10 \mathrm{ft} / \mathrm{sec}\) and at a potential of \(10 \mathrm{ft}\) with respect to the other connections shown in Figure P2.14. Steam enters at the rate of \(1 \mathrm{lbm} / \mathrm{sec}\) with a velocity of \(50 \mathrm{ft} / \mathrm{sec}\) and an enthalpy of \(1350 \mathrm{Btu} / \mathrm{lbm}\). These two streams mix in the heater, and hot water emerges with an enthalpy of \(168 \mathrm{Btu} / \mathrm{lbm}\) and a velocity of 12 \(\mathrm{ft} / \mathrm{sec}\).

(a) Determine the heat lost from the apparatus.

(b) What percentage error is involved if both kinetic and potential energy changes are neglected?

Transcribed Image Text:

Cold water 10 ft Steam Heater Hot water Figure P2.14