Chapter 9, Problem 9.115EP

Q1- A boiler generates 500 kg/h of steam at 16 bar and 300C from feed water at 30°C. Coal used is 60 kg/h of C.V 30000 kJ/kg. Find equivalent of evaporation and boiler efficiency. Ans(10. 75 kgs/kgf 80.9%) Q2// For simple Rankine cycle, the steam used by the turbine is 5.4 kg/kWh at a pressure of 50 bar and a temperature of 350°C. The efficiency of the boiler is 82% with feed water at 150 °C. a- How many kg of coal are required per kWh? The Calorific value of fuel is 28100kJ/kg. b-if the cost of coal is 10S per ton, then what is the fuel cost per kWh. Ans(82%, 5.72E-3)

Steam at 6.2 MPa and 480 deg. C is received by a regenerative engine with ideal conditions and in an ideal cycle. Extractions for feedwater heating occurs at 3 MPa and again at 1.4 MPa, with the remaining steam expanding to 0.0065 MPa. What is m; in kg/hr?

refer to the table below. Apply interpolation if necessary

3.) In In an actual Rankine cycle, steam first enters the turbine at 10 MPa and 400C. It expands to a pressure of 10 kPa as saturated vapor and it then enters a pump with 85% efficiency after condensing. a.) Draw the proper T-S diagram of the cycle with proper label for the points. b.) Find the quality of the steam, Qa, Qr, Wt, Wp. Wnet, efficiency, and steam rate kg kWh 2892.802392.87511.8 11.87 499.93 17.28%, 7.20 kg kg

3. Consider a reheat cycle utilizing steam. Steam leaves the boiler and enters the turbine at 4 MPa, 400°C. After expansion in the turbine to 400 kPa, the steam is reheated to 400°C and then expanded in the low pressure turbine to 10 kPa. Determine the cycle efficiency. Ans. 35.9%

PLEASE SHOW COMPLETE SOLUTION (DRAW THE TS DIAGRAM)

Provide complete solution and detailed diagram.  What is the resulting pressure when one pound of air at 15 psia and 200oF is heated at constant volume to 800oF?  A. 180 psia           B. 28.6 psia            C. 36.4   psia              D. 521.1  psia

B1

1. A reheat steam cycle has 13.65 MPa pressure at the high pressure turbine inlet and a 2500 kPa reheat pressure, the temperature at the inlet of the high pressure turbine and reheat temperature of the steam is 540 °C, condenser pressure is 3.4 kPa, engine efficiency of high pressure and low pressure turbine are both 75 %. Sketch the cycle lay out and cycle T-s diagram. a. Find the enthalpy at each state point. (Summarize) b. Find the actual enthalpy at the exit of the high-pressure turbine and low-pressure turbine. Find the cycle thermal efficiency С. d. If the net power at the turbine is 100 MW find the mass flow rate of steam, in kg/s; Heat rejected by the condenser, in MW е.