Page 74 - Handbook of Energy Engineering Calculations

FIGURE 11 (a) Cycle diagram with test conditions. (b) T-S diagram
for cycle.

(a) The percent throttle steam bled is found from: 100 × (H − H )/(H −
4
5
2
H ) = 100 × (177.9 − 46.92)/(1106 − 46.92) = 12.41 percent.
4
2. Find the amount of heat converted to work
(b) Use the relation, heat converted to work, h = H − H + (1 − m )(H −
w
2
1
2
2
H ), where m = percent throttle steam bled, H = enthalpy of exhaust steam
2
7
7
in the condenser. Substituting, heat converted to work, h = (1366 − 1106) +
w
(1 − 0.1241)(1106 − 924.36) = 419.1 Btu/lb (976.5 kJ/kg).
3. Compute the ideal steam rate