Chapter 9, Problem 9.39P

10 0.9967. Ans. H.W 2 A smaller power plant produces steam at 3 MPa, 600 C, in the boiler. It keeps the condenser at 45 C by the transfer of 10MW out as heat transfer. The first turbine section expands to 500 kPa, and then flow is reheated followed by the expansion in the low-pressure turbine. Find the reheat temperature so that the turbine output is saturated vapor. For this reheat, find the total turbine power output and the boiler heat transfer. Answer. (Reheat temperature= 529°C , total turbine power output= 6487 kW, the boiler heat transfer= 16 475 kW)

9.13 A steam power plant should produce 10 MW net work. Steam flows at 5 MPa, 500°C to the turbine which has a condenser exit at 50°C. Find the mass flow rate of steam needed. 9.14 For the previous problem find all the specific work and heat transfer terms and the cycle efficiency.

A smaller power plant produces 25 kg/s steam at 3 MPa, 600o C in the boiler. It cools the condenser with ocean water so the condenser exit is at 45o C. There is a reheat done at 500 kPa up to 400o C and then expansion in the low pressure turbine. For the engine find W and ?? .

Cogeneration is often used where a steam supply is needed for industrial process energy. Assume a supply of 5 kg/s steam at 0.5 MPa is needed. Rather than generating this from a pump and boiler, the setup in below. is used so the supply is extracted from the high-pressure turbine. Find the power the turbine now cogenerates in this process. 2 3 HP LP

Saturation: Pressures Specifie Volume Sa Internal Energy Sal Ligule Entropy Set. Ligurd Enthalpy Pr Tegp Ligld 10, Sat. Vaper Sal. Liquid Sat Veper Sat. Vapor Erap Er 10 DO06113 .0007 COC3 .co09 01 1.0002 206 136 1.89 1.0001 181 255 3.77 1.0001 159 675 5.45- 1.0001 142 789 00 2.75.3 23753 7.90 23700 2377.9 15.81 2364.7 23806 22.88 23600 2382.9 · O1 25013 2501.4 7.91 24969 2504 8 15.81 2492.5 2508.3 22.89 2488 5 2511.4 0000 9.1562 9.1562 0288 9.0775 9,1064 0575 8.9999 9.0573 ON29 8.9312 9,0:42 .0010 0011 0012 0013 .0014 6.98 1.0002 129 208 8.37 1.0002 118 042 9.66 LO003 108 696 10.86 11.98 29.30 2355.7 2385.0 35.17 23518 2386.9 40.58 2348.1 2388.7 45.60 2344.7 23903 50.31 23416 2391.9 29.30 24849 2514.2 35.17 2481.6 2516.8 40.58 2478.6 2519.1 45.60 2475.7 25213 503I 2473.1 2523.4 1059.R8697 8.9756 1268 8.8140 8.9408 1460 8.7631 8.9091 1637 8.7162 8.8799 1802 8.6727 8.8529 1.0004 100 755 1.0005 93 922 54.71 2338.6 2393.3 58.87 2335.8 2394.7 62.80 2333.2 2396.0 66.53 2330.7 23972 70.09…

SOLVE 4 KNLY

Steam is supplied to a turbine at 600 psia  with 200 F superheated and exhausts to the condenser at 0.7 psia  . Assume the process to be isentropic and use the steam table to find :  a.) The entropy and enthalpy at inlet. b.) The enthalpy and moisture content at exhaust.

An ideal reheat turbine with one stage of reheat receives steam at 8.0 MPa, 480 ̊C.Reheat pressure is 0.83 MPa and exhaust pressure is 0.007 MPa. The work is 1559kJ/kg and the thermal efficiency is 41.05%. Find the temperature of steam leaving thereheater.

Reheat steam has 2000 psia throttle pressure at the turbine inlet and 410 kPa reheat pressure, the throttle and reheat temperature of the steam is 1010 F, condenser pressure is 0.50 psia, engine efficiency of high pressure and low pressure is 75%. Find the cycle thermal efficiency.