1. In a combined gas-steam power cycle, the topping cycle is a gas-turbine cycle that has a pressure ratio of 7. Air enters the compressor at 310 K and the turbine at 1310 K. The process in turbines, compressor, and pump are isentropic. The bottoming cycle is a simple ideal Rankine cycle operating between the pressure limits of 7 MPa and 10 kPa. Steam is heated in a heat exchanger by the exhaust gases to a temperature of 00°C. The exhaust gases leave the heat exchanger at 450 K. Determine (a) the ratio of the mass flow rates of the steam and the combustion gases and (b) the thermal efficiency of the combined cycle.

1. In a combined gas-steam power cycle, the topping cycle is a gas-turbine cycle that has a pressure ratio of 7. Air enters the compressor at 310 K and the turbine at 1310 K. The process in turbines, compressor, and pump are isentropic. The bottoming cycle is a simple ideal Rankine cycle operating between the pressure limits of 7 MPa and 10 kPa. Steam is heated in a heat exchanger by the exhaust gases to a temperature of 00°C. The exhaust gases leave the heat exchanger at 450 K. Determine (a) the ratio of the mass flow rates of the steam and the combustion gases and (b) the thermal efficiency of the combined cycle.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

A simple power plant utilizing the Rankine Cycle operates with an inlet boiler pressureof 5 MPa and an inlet condenser pressure of 300 kPa. Because of frictional effects, thepressure of the water drops 0.3 MPa in the boiler and 3 kPa in the condenser. Thetemperature of the steam as it enters the turbine is 700 °C. The adiabatic efficiency ofthe pump and of the turbine are 83 percent and 88 percent, respectively. The pumpand the turbine are adiabatic, and the water enters the pump as saturated liquid. It canbe assumed that heat transfer to the water in the boiler is from a reservoir at 1500 K,and the environment is at 25 °C.Determine the thermal efficiency of the cycle and compare it with the thermal efficiencyof (a) a Carnot cycle, and (b) the ideal Rankine Cycle. Specify the amount of entropygenerated in each step of the real cycle
A gas-turbine power plant operates on the simple Brayton cycle between the pressure limits of 200 and 1500 kpa. The working fluid as air, which enters the compressor at 30C at a rate of 20 kg/s and enters at the turbine at 900k. Using variable specific heats for air and assuming a compressor isoentropic afficiency of 90 % and a turbine isentropic efficiency of 100%, determine a) the net power output, b) the back work ratio, and c) the thermal efficiency
A simple rankine ideal cycle with water as the working fluid. Twenty kilograms of steam enters the turbine at 7.356 MPa and 500.356 oC and is cooled in the condenser at a pressure of 10.356 KPa by running cooling water from a lake through the tubes of the condenser at rate of 2000 kg. Show the T-s diagram and schematic of simple rankine cycle. For cycle determin (a) the turbine work, (b) the heat added, (c) the temperature rise of the cooling water, (d) the thermal efficiency of the cycle. For engine, determine (e) the heat added, (f) the thermal efficiency of the engine, and (g) Draw the T-s and schematic diagram.
Consider a simple Brayton cycle that uses air as the working fluid to operate a gas-turbine power plant between the pressure limits of 100kPa and 900kPa. Air enters the compressor at 298K and leaves at 610K at a mass flow rate of 1200kg/min. The maximum cycle temperature is 1380K. The net power output from the cycle is measured experimentally to be 55 MW. Assuming constant properties (Cv,Cp, R, and k) for air at 300K: a) Sketch a T-s diagram for the cycle b) Determine the isentropic efficiency of the turbine c) Determine the thermal efficiency
In a Rankine Cycle , saturated liquid water at 1 bar is compressed isentropically to 150 bar. First by heating in a boiler and then by superheating at constant pressure of 150 Bar, the water substance is brought to 750 K. After Adiabatic reversible expansion in a turbine at 1 Bar, it is then cooled in a condenser to a saturated liquid. How much work is generated in the turbine? (include diagram)
An ideal Rankine cycle operates between the pressure limits of 15,000 kPa in the boiler and 15 kPa in the condenser. If the turbine inlet temperature is 500 deg C and the cycle produces 2500 kW of net work, determine the mass flow rate of the steam in kg/s. Refer to the tables below. a. 1.993 b. 2.122 c. 1.856 d. 2.016
A stationary gas-turbine power plant operates on an ideal regenerative Brayton cycle (∊ = 100 percent) with air as the working fluid. Air enters the compressor at 95 kPa and 290 K and the turbine at 880 kPa and 1100 K. Heat is transferred to air from an external source at a rate of 30,000 kJ/s. Determine the power delivered by this plant accounting for the variation of specific heats with temperature.
1.5An ideal Rankine cycle with reheat uses water as the working fluid. As shown in the figure below, the conditions at the inlet to the first turbine stage are 1600 lbf/in.2, 1200°F and the steam is reheated to a temperature of T3 = 800°F between the turbine stages at a pressure of p3 = p2 = 200 lbf/in.2 For a condenser pressure of p5 = p4 = 1 lbf/in.2, determine:(a) the quality of the steam at the second-stage turbine exit. h6≈h5+v5(p6−p5)h6≈h5+v5(p6-p5)Determine the quality of the steam at the second-stage turbine exit. x4 =(b) the cycle percent thermal efficiency.
In an ideal Reheat cycle , the steam throttled condition is 7 Mpa and 460 C. The steam is then reheated to 1.5 MpA and 460 C . If turbine exhaust is 50 C ,determine the following: A.) Quality after turbine expansion B.) Turbine work C.) Heat added in the boiler D.) Heat rejected from the condenser E.) Pump work F.) Net work G.) Cycle efficiency
A steam power plant operating on an intermediate steam Rankine cycle has an open feedwater heater. The enthalpy of the steam at the turbine inlet is 3208 kJ/kg, the enthalpy at the split point is 2648 kJ/kg, and the enthalpy at the turbine exit is 2158 kJ/kg. The net power of the power plant is 100 MW, and the mass ratio of the steam leaving the turbine in the intermediate steam intake is 0.244. What is the mass flow rate of steam at the turbine inlet if the pump work is ignored?
In ideal regenerative Rankin cycle receives 50000 kg/hr of steam throttled with three open feedwater heaters, steam enters the turbine at 15.356 Mpa and 700.356 oC. It is condensed in the condenser at a pressure of 150.356 kPa. Steam extracted at the following points: 15.0356 Mpa,10.0356 Mpa and 5.0356 Mpa to enter the open feedwater heaters simultaneously. A.) Determine the extracted steams from the turbine, in kg/s. Calculate the thermal efficiency of the (b) cycle, % and (c) engine, %.
Steam is the working fluid in an actual Rankine cycle. Steam enters the turbine at 8.0 MPa and 550 deg. C; and saturated liquid exits the condenser at a pressure of 0.008 MPa. The net power output of the cycle is 110 MW. The turbine and the pump each have an isentropic efficiency of 83% Illustrate and label the TS diagram and determine the cycle (a) the cycle thermal efficiency (b) the back work ratio (c)the mass flow rate of the steam, in kg/h, (d) the rate of heat transfer into the working fluid as it passes through the boiler, in MW, (e) the rate of heat transfer, from the condensing steam, as it passes through the condenser, in MW, (f) the mass flow rate of the condenser cooling water, in kg/hr., if cooling water enters the condenser at 15 deg. C and exits at 35 deg. C.