problems in chapter 9 cb thermodynamics - lth a steam power plant operates on the reheat rankine...

Department of Energy SciencesThermal power engineering, HT 2017

http://www.tpe.energy.lth.se/Marcus Thern

Problems in chapter 9 CB Thermodynamics

9-82 Air is used as the working fluid in a simple ideal Brayton cycle that has a pressure ratio of 12,a compressor inlet temperature of 300K, and a turbine inlet temperature of 1000K. Determinethe required mass flow rate of air for a net power output of 70MW, assuming both the compressorand the turbine have an isentropic efficiency of (a) 100% and (b) 85%. Assume constant specificheats at room temperature.

Solution: Answers: (a) 352kg/s, (b) 1037kg/s

9-85 A gas-turbine power plant operates on the simple Brayton cycle between the pressure limitsof 100 and 1600kPa. The working fluid is air, which enters the compressor at 40◦C at a rate of850m3/min and leaves the turbine at 650◦C. Using variable specific heats for air and assuming acompressor isentropic efficiency of 85% and a turbine isentropic efficiency of 88%, determine (a)the net power output, (b) the back work ratio, and (c) the thermal efficiency.

Solution: Answers: (a) 6083kW with T3 = 1352.9◦C, (b) 0.535, (c) 37.4%

9-86 A gas-turbine power plant operates on a simple Brayton cycle with air as the working fluid.The air enters the turbine at 800kPa and 1100K and leaves at 100kPa and 670K. Heat is rejectedto the surroundings at a rate of 6700kW, and air flows through the cycle at a rate of 18kg/s.Assuming the turbine to be isentropic and the compresssor to have an isentropic efficiency of80%, determine the net power output of the plant. Account for the variation of specific heats withtemperature.

Solution: Answer: 2979kW

9-87 For what compressor efficiency will the gas-turbine power plant in Problem 9-86 producezero net work?

Solution: Answer:

9-90 How does regeneration affect the efficiency of a Brayton cycle, and how does it accomplish it?

Solution: Answer:

9-94 A gas turbine for an automobile is designed with a regenerator. Air enters the compressorof this engine at 100kPa and 20◦C. The compressor pressure ratio is 8; the maximum cycletemperature is 800◦C; and the cold air stream leaves the regenerator 10◦C cooler than the hotair stream at the inlet of the regenerator. Assuming both the compressor and the turbine tobe isentropic, determine the rates of heat addition and rejection for this cycle when it produces150kW. Use constant specific heats at room temperature.

Solution: Answer: 303kW and 153kW


10-15 Consider a 210MW steam power plant that operates on a simple ideal Rankine cycle.Steam enters the turbine at 10MPa and 500◦C and is cooled in the condenser at a pressure of10kPa. Show the cycle on a T-s diagram with respect to saturation lines, and determine (a) thequality of the steam at the turbine exit, (b) the thermal efficiency of the cycle, and (c) the massflow rate of the steam.

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Solution: Answers: (a) 79.3 %, (b) 40.2 %, (c) 165 kg/s

10-19 A simple Rankine cycle uses water as the working fluid. The boiler operates at 6000kPaand the condenser at 50kPa. At the entrance to the turbine, the temperature is 450◦C. Theisentropic efficiency of the turbine is 94%, pressure and pump losses are negligible, and the waterleaving the condenser is subcooled by 6.3◦C. The boiler is sized for a mass flow rate of 20kg/s.Determine the rate at which heat is added in the boiler, the power required to operate the pumps,the net power produced by the cycle, and the thermal efficiency.

Solution: Answers: 59.660 kW, 122 kW, 18.050 kW, 30.3 %

10-23 Consider a coal-fired steam power plant that produces 175 MW of electric power. The powerplant operates on a simple ideal Rankine cycle with turbine inlet conditions of 7 MPa and 550 ◦Cand a condenser pressure of 15 kPa. The coal has a heating value (energy released when the fuelis burned) of 29.3 MJ/kg. Assuming that 85 % of this energy is transferred to the steam in theboiler and that the electric generator has an efficiency of 96 %, determine (a) the overall plantefficiency (the ratio of net electric power output to the energy input as fuel) and (b) the requiredrate of coal supply.

Solution: Answers: (a) 31.5 %, (b) 68.3 t/h

10-31 Consider a steam power plant that operates on the ideal reheat Rankine cycle. The plantmaintains the boiler at 5000kPa, the reheat section at 1200kPa, and the condenser at 20kPa.The mixture quality at the exit of both turbines is 96.0%. Determine the temperature at the inletof each turbine and the cycle’s thermal efficiency.

®

Rehe tr @

Pu1np

Q)

L w-P urbin

! ®

Figure 1: Assignment 10.31

Solution: Answers: 327 ◦C, 481 ◦C, 35.0 %

10-33 A steam power plant operates on the reheat Rankine cycle. Steam enters the high-pressureturbine at 12.5MPa and 550◦C at a rate of 7.7kg/s and leaves at 2MPa. Steam is then reheatedat constant pressure to 450◦C before it expands in the low-pressure turbine. The isentropic

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efficiencies of the turbine and the pump are 85% and 90%, respectively. Steam leaves thecondenser as a saturated liquid. If the moisture content of the steam at the exit of the turbineis not to exceed 5%, determine (a) the condenser pressure, (b) the net power output, and (c) thethermal efficiency.

Pump

Q)


Solution: Answers: (a) 9.73 kPa, (b) 10.2 MW, (c) 36.9 %

10-41 The closed feedwater heater of a regenerative Rankine cycle is to heat 7000kPa feedwaterfrom 260◦C to a saturated liquid. The turbine supplies bleed steam at 6000kPa and 325◦C tothis unit. This steam is condensed to a saturated liquid before entering the pump. Calculate theamount of bleed steam required to heat 1kg of feedwater in this unit.

Bleed te m

from turbine


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Solution: Answer: 0.0757 kg/s

10-42 A steam power plant operates on an ideal regenerative Rankine cycle. Steam enters theturbine at 6MPa and 450◦C and is condensed in the condenser at 20 kPa. Steam is extractedfrom the turbine at 0.4 MPa to heat the feedwater in an open feedwater heater. Water leaves thefeedwater heater as a saturated liquid. Show the cycle on a T-s diagram, and determine (a) themass flow rate of steam through the boiler and (b) the thermal efficiency of the cycle

Solution: Answers (a) 1017 kJ/kg (b) 37.8 %

10-43 Repeat previous problem by replacing the open feedwater heater with a closed feedwaterheater. Assume that the feedwater leaves the heater at the condensation temperature of theextracted steam and that the extracted steam leaves the heater as a saturated liquid and ispumped to the line carrying the feedwater.

Solution: Answers (a) 1016.8kJ/kg (b) 37.8%

10-45 Consider a steam power plant that operates on the ideal regenerative Rankine cycle with aclosed feedwater heater as shown in the figure. The plant maintains the turbine inlet at 3000kPaand 350◦C; and operates the condenser at 20kPa. Steam is extracted at 1000kPa to serve theclosed feedwater heater, which discharges into the condenser after being throttled to condenserpressure. Calculate the work produced by the turbine, the work consumed by the pump, and theheat supply in the boiler for this cycle per unit of boiler flow rate.

boiler


Solution: Answers: 741kJ/kg, 3.0kJ/kg, 2353kJ/kg

10-52 A steam power plant operates on an ideal reheat- regenerative Rankine cycle and has anet power output of 80MW. Steam enters the high-pressure turbine at 10MPa and 550◦C andleaves at 0.8MPa. Some steam is extracted at this pressure to heat the feedwater in an open

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feedwater heater. The rest of the steam is reheated to 500 ◦C and is expanded in the low-pressureturbine to the condenser pressure of 10kPa. Show the cycle on a T-s diagram with respect tosaturation lines, and determine (a) the mass flow rate of steam through the boiler and (b) thethermal efficiency of the cycle

Solution: Answers (a) 54.5kg/s (b) 44.4%

Heat exchanger problems

HEX 001 A feedwater train with five closed feed water heaters and no pumps. The feedwaterheaters heat the feedwater to a temperature of 250 ◦C. The condensor temperature is 80 ◦C. Deter-mine the optimum temperature between the heaters. The optimum division of the temperaturesin the feed water train was given in the lecture as

Tk

T1= T1

T2= . . .= Tn−1

Tn= k (1)

which can be expressed as

k = n

√Tk

Tn(2)

where

Tk Temperature after the condenser [K]Tn Temperature after nth feed water heater[K]k Constantn Number of feed water heaters

Solution: Answer: T2 = 108.88◦C, T3 = 140.11◦C, T4 = 173.90◦C, T5 = 210.46◦C

HEX 002 A power plant has three feedwater heaters. The steam temperature is 5 ◦C above thetemperature of the feedwater that leaves the feedwater heater. There is no sub-cooling in thefeedwater heater and there are no pressure losses. The final feedwater temperature is not known,Tn

Steam flow before turbine 100 kg/sInlet pressure 100 barInlet temperature 500 ◦CTurbine isentropic efficiency 87 %Grädigkeit 5 ◦CCondenser pressure 0.58 barTemperature after the condenser 85 ◦C

Calculate for the following cases TnTn−1

=1.08, 1.1 and 1.12

Solution: (Answer for first case: Tk = 85◦C, T1 = 113.7◦C, T2 = 144.6◦C och T3 = 178◦C)

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HEX 003 In a factory that produce olive oil the oil must be cooled after it has been pressed. Thisis performed in two heat exchangers (see figure) with fresh water. The olive oil is cooled from45 ◦C to 23 ◦C. Calculate the cooling water flow if the oil flow is V oil = 450dm3/h. The densityfor the oil is ρoil = 915kg/m3 and the specific heat for oil is cp,oil = 1.65kJ/(kgK). Water has thedensity ρw = 1000kg/m3 and a specific heat of cp,w = 4.18kJ/(kgK).

Twater = 13°C Twater = 19°C

Toil = 45°CToil = 23°C

Figure 5: Assignment HEX 003

Solution: (Answer: No answer at the moment.)

HEX 004 Oil with a temperature of 100◦C is to be cooled in a counter-current heat exchanger.Cooling water is available at a temperature of 10◦C. The heat transfer area in the heat exchangeris 50m2 and the flow of oil is 1.8 kg/s and the cooling water flow is 1.7kg/s. The following datais known. The oil coolers heat transfer coefficient, U = 116W/(m2 K). The specific heat of the oil,cv = 1.98kJ/(kgK) and the specific heat of the water is ck = 4.19kJ/(kgK). Calculate the oil andwater temperature at the exit of the heat exchanger and calculate the amount of heat transferedby the heat exchanger.

Solution: (Answer: T1 = 35.63◦C, T2 = 42.21◦C and Q = 229.4kW)


11-16 Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.20 MPaand −5 ◦C at a rate of 0.07 kg/s, and it leaves at 1.2 MPa and 70 ◦C. The refrigerant is cooledin the condenser to 44 ◦C and 1.15 MPa, and it is throttled to 0.21 MPa. Disregarding any heattransfer and pressure drops in the connecting lines between the components, show the cycle ona T-s diagram with respect to saturation lines, and determine (a) the rate of heat removal fromthe refrigerated space and the power input to the compressor, (b) the isentropic efficiency of thecompressor, and (c) the COP of the refrigerator.

Solution: Answers: 9.42 kW, 3.63 kW, 74 %, 30.3 % 2.60

11-22 An actual refrigerator operates on the vapor compression refrigeration cycle with refrigerant-22 as the working fluid. The refrigerant evaporates at −15 ◦C and condenses at 40 ◦C. Theisentropic efficiency of the compressor is 83 %. The refrigerant is superheated by 5 ◦C at the com-pressor inlet and subcooled by 5 ◦C at the exit of the condenser. Determine (a) the heat removedfrom the cooled space and the work input, in kiloJ/kg and the COP of the cycle. Determine (b) thesame parameters if the cycle operated on the ideal vapor-compression refrigeration cycle betweenthe same evaporating and condensing temperatures. The properties of R-22 in the case of actualoperation are: h1 = 402.49kJ/kg, h2 = 454.00kJ/kg, h3 = 243.19kJ/kg. The properties of R-22in the case of ideal operation are: h1 = 399.04kJ/kg, h2 = 440.71kJ/kg, h3 = 249.80kJ/kg, Note:

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state 1: compressor inlet, state 2: compressor exit, state 3: condenser exit, state 4: evaporatorinlet.

Solution: Answers: 3.093 and 3.582

11-42 A heat pump with refrigerant-134a as the working fluid is used to keep a space at 25 ◦C byabsorbing heat from geothermal water that enters the evaporator at 50 ◦C at a rate of 0.065 kg sand leaves at 40 ◦C. The refrigerant enters the evaporator at 20 ◦C with a quality of 23 % andleaves at the inlet pressure as saturated vapor. The refrigerant loses 300 W of heat to thesurroundings as it flows through the compressor and the refrigerant leaves the compressorat 1.4 MPa at the same entropy as the inlet. Determine (a) the degrees of subcooling of therefrigerant in the condenser, (b) the mass flow rate of the refrigerant, (c) the heating load and theCOP of the heat pump, and (d) the theoretical minimum power input to the compressor for thesame heating load.

Expan ion

valve

Evaporator

© 20°c

x=0.23 t Water 40°C

50°C

t Compressor

CD at. vapor

Figure 6: Assignment 1142

Solution: Answers:3.8 ◦C, 0.0194 kg/s, 3.07 kW and 4.68, 0.238 kW

11-52 A two-stage compression refrigeration system operates with refrigerant-134a between thepressure limits of 1.4 MPa and 0.10 MPa. The refrigerant leaves the condenser as a saturatedliquid and is throttled to a flash chamber operating at 0.6 MPa. The refrigerant leaving thelow-pressure compressor at 0.6 MPa is also routed to the flash chamber. The vapor in the flashchamber is then compressed to the condenser pressure by the high-pressure compressor, and theliquid is throttled to the evaporator pressure. Assuming the refrigerant leaves the evaporator assaturated vapor and both compressors are isentropic, determine (a) the fraction of the refrigerantthat evaporates as it is throttled to the flash chamber, (b) the rate of heat removed from the

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refrigerated space for a mass flow rate of 0.25 kg/s through the condenser, and (c) the coefficientof performance.

Solution: Answers:0.2528, QL = 28.57kW, COPR = 2.50


15-18 In a combustion chamber, ethane C2H6 is burned at a rate of 8kg/h with air that enters thecombustion chamber at a rate of 176kg/h. Determine the percentage of excess air used duringthis process.

Solution: Answer: 37%

15-23 A fuel mixture of 60% by mass methane CH4 and 40% by mass ethanol C2H6O, is burnedcompletely with theoretical air. If the total flow rate of the fuel is 10kg/s, determine the requiredflow rate of air.

Solution: Answer: 139kg/s

15-28 Methane CH4 is burned with dry air. The volumetric analysis of the products on a dry basisis 5.20% CO2, 0.33% CO, 11.24% O2, and 83.23% N2. Determine (a) the air-fuel ratio and (b) thepercentage of theoretical air used.

Solution: Answers: (a) 34.5 kgair/kgfuel, (b) 200%

15-40 Determine the enthalpy of combustion of methane CH4 at 25◦C and 1atm, using theenthalpy of formation data from Table A-26. Assume that the water in the products is in theliquid form. Compare your result to the value listed in Table A-27.

Solution: Answer: −890330kJ/kmol

15-47 Calculate the higher and lower heating values of a coal from Illinois which has an ultimateanalysis (by mass) as 67.40% C, 5.31% H2, 15.11% O2, 1.44% N2, 2.36% S, and 8.38% ash(non-combustibles). The enthalpy of formation of SO2 is 297100kJ/kmol.

Solution: Answer: 32650kJ/kg, 31370kJ/kg

15-59 Diesel fuel C12H26 at 25◦C is burned in a steadyflow combustion chamber with 20% excessair that also enters at 25◦C. The products leave the combustion chamber at 500K. Assumingcombustion is complete, determine the required mass flow rate of the diesel fuel to supply heat ata rate of 2000kJ/s.

Solution: Answer: 49.5g/s

15-61 A gaseous fuel mixture that is 40 percent propane C3H8 and 60 percent methane CH4 byvolume is mixed with the theoretical amount of dry air and burned in a steadyflow, constantpressure process at 100kPa. Both the fuel and air enter the combustion chamber at 298K andundergo a complete combustion process. The products leave the combustion chamber at 423K.Determine(a) the balanced combustion equation,(b) the amount of water vapor condensed from the products, and(c) the required air flow rate, in kg/h, when the combustion process produces a heat transferoutput of 140000kJ/h.

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h0f , kJ/kmol M, kg/kmol cp kJ/(kgK)

C3H8 -103,850 44CH4 -74,850 16CO2 -393,520 44 41.16CO -110,530 28 29.21H2O (g) -241,820 18 34.28H2O (l) -285,830 18 75.24O2 0 32 30.14N2 0 28 29.27

Solution: Answer: (c) 50.1kg/h

15-70 Estimate the adiabatic flame temperature of an acetylene C2H2 cutting torch, in ◦C, whichuses a stoichiometric amount of pure oxygen.

Solution: Answer: 8832◦C with cp,H2O = 1.8723kJ/(kgK) and cp,CO2 = 1.234kJ/(kgK)

15-72 Acetylene gas C2H2 at 25◦C is burned during a steady-flow combustion process with 30%excess air at 27◦C. It is observed that 75000kJ of heat is being lost from the combustion chamberto the surroundings per kmol of acetylene. Assuming combustion is complete, determine the exittemperature of the product gases.

Solution: Answer: 2301K

15-83 Liquid propane C3H8 enters a steady-flow combustion chamber at 25◦C and 1atm at arate of 0.4kg/min where it is mixed and burned with 150% excess air that enters the combustionchamber at 12◦C. If the combustion products leave at 1200K and 1atm, determine (a) the massflow rate of air, (b) the rate of heat transfer from the combustion chamber, and (c) the rate ofentropy generation during this process. Assume T0 = 25◦C.

Solution: Answer: (a) 15.7kg/min, (b) 1730kJ/min, (c) 38.07kJ/min/K, with sC3H8(l)= 220.3628kJ/(kmolK) and Sgen = 3815.1kJ/K/kmolC3H8

15-97 A liquid-gas fuel mixture consists of 90% octane C8H18, and 10% alcohol C2H5OH, bymoles. This fuel is burned with 200% theoretical dry air. Write the balanced reaction equationfor complete combustion of this fuel mixture. Determine (a) the theoretical air-fuel ratio for thisreaction, (b) the product-fuel ratio for this reaction, (c) the air-flow rate for a fuel mixture flowrate of 5kg/s, and (d) the lower heating value of the fuel mixture with 200% theoretical air at25◦C.

Solution: Answer: (a) 14.83kgair/kgfuel, (b) 30.54kgproduct/kgfuel, (c) 148.3kg/s,(d) 43760kJ/kgfuel

Extra gas turbine problems

In these assignments please use constant specific heats according to

For air: cpa = 1.005kJ/(kgK) k = 1.400

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For combustion gas: cpg = 1.148kJ/(kgK) k = 1.333

The gas constant for air and combustion gases, R = 0.287kJ/kg.

In order to calculate the fuel-air-ratio you will need the following set of equations

x1 = 0.10118+2.00376×10−5 · (700−T02)

x2 = 3.7078×10−3 −5.2368×10−6 · (700−T02)−5.2632×10−6 ·T03

x3 = 8.889×10−8 ·∣∣∣(T03 −950

)∣∣∣f =

x1 −√

x21 + x2 − x3

ηb

The lower heating value of the fuel is 43 100 kJ/kg which can be used to calculate the efficiency ofa cycle according to the following equation

η= Wnet

mfuel ·LHV

1. A compressor has an isentropic efficiency of 0.85 at a pressure ratio of 4.0. Calculate thecorresponding polytropic efficiency, and thence plot the variation of isentropic efficiency overa range of pressure ratio from 2.0–10.0

2. A peak-load generator is to be powered by a simple gas turbine with free power turbinedelivering 20 MW of shaft power. The following data are applicable:

Compressor pressure ratio 11.0Compressor isentropic efficiency 0.82Combustion pressure loss 0.4barCombustion efficiency 0.99Turbine inlet temperature 1150KGas-generator turbine isentropic efficiency 0.87Power-turbine isentropic efficiency 0.89Mechanical efficiency (each shaft) 0.98Ambient conditions, pa, Ta 1 bar, 288 K

Calculate the air mass flow required and the SFC.

3. A gas turbine for use on a large airliner uses a single-shaft configuration with air bled fromthe compressor discharge for aircraft services. The unit must provide 1.5 kg/s bleed air and ashaft power of 200 kW. Calculate (a) the total compressor air mass flow and (b) the poweravailable with no bleed flow, assuming the following

Compressor pressure ratio 3.80Compressor isentropic efficiency 0.85

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Combustion pressure loss 0.12 barTurbine inlet temperature 1050 KTurbine isentropic efficiency 0.88Mechanical efficiency (compressor rotor) 0.99Mechanical efficiency (driven load) 0.98Ambient conditions, pa, Ta 1 bar, 288 K

[ma = 4.676kg/s, W = 640.154kW]

4. A single-shaft gas turbine for electric power generation has been steadily developed overtime. Cycle data for three versions are given below. A being the initial version

A B CPolytropic efficiency (compressor) 0.87 0.88 0.89Polytropic efficiency (turbine) 0.89 0.88 0.88Compressor pressure ratio 9.0 12.0 16.0Compressor pressure loss (%) 5.0 5.0 5.0Turbine inlet temperature (K) 1150 1400 1600Rotor cooling bleed (%) – 2.5 5.0Airflow (kg/pers) 75.0 80.0 85.0

Assume combustion efficiency and mechanical efficiency are both 99 % and ignore inlet andexhaust pressure losses.

(a) Calculate the power and SFC for each version.

(b) Calculate the percentage improvement from version A.

(c) Calculated the exhaust gas temperature for each version and comment on their effectfor a cogeneration plant.

[SFC = 0.282 kg/(kW h), 0.259 kg/(kW h) and 0.244 kg/(kW h) ] EGT = 713.659 K, 819.943 Kand 879.209 K T03 −T04 = 436.341 K, 580.057 K and 720.351 K]

5. Using the data from Example 3 and assuming a reheat pressure of 13 bar, evaluate the powerand thermal efficiency for reheat temperatures of 1525 K, 1425 K and 1325 K. Would this bea good strategy for part-load operation? [240, 214.6, 189.2 MW, efficiency almost constant]

6. The following data refer to an intercooled gas turbine, with a twinspool gas generator and afree power turbine:

LP compressor pressure ratio 5.5HP compressor pressure ratio 7.5Air temperature after intercooler 300 KTurbine inlet temperature 1550 KRotor cooling bleed 5 %LP compressor isentropic efficiency 0.875

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HP compressor isentropic efficiency 0.870LP turbine isentropic efficiency 0.89HP turbine isentropic efficiency 0.88Power-turbine isentropic efficiency 0.89

Neglect inlet, intercooler and exhaust pressure losses. Calculate

(a) Airflow required for an output of 100MW.

(b) Thermal efficiency.

(c) Exhaust gas temperature.

[192.97kg/s, 43.7%, 421◦C]

7. A gas turbine is to be designed for continuous duty at a rating of 4MW. Compare thefollowing two cycles and comment on their suitability for this role. Also comment on theirpotential for use in a small cogeneration plant.

Regenerative cycle

Pressure ratio 9.0Turbine inlet temperature 1450 K

Simple cycle:

Pressure ratio 14.0Turbine inlet temperature 1450 K

8. The following data apply to a regenerative cycle industrial gas turbine:

Compressor pressure ratio 8.5LP compressor isentropic efficiency 0.87Turbine inlet temperature 1285 KGas generator turbine isentropic efficiency 0.87Power-turbine isentropic efficiency 0.88Mechanical efficiency (both shafts) 0.99Combustion efficiency 0.99Combustion pressure loss (of comp. delivery press.) 4.2 %Regenerator effectiveness 0.90Regenerator pressure loss

cold side (of compressor delivery pressure) 1.5 %hot side (of atmospheric pressure) 2.0 %

Mass flow 112.0kg/s

Ambient conditions, 1.013bar and 15◦C

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(a) Calculate the power output and thermal efficiency. [27927kW, 41.8%]

(b) If this engine were to be used in a combined cycle application, what changes would yousuggest?

[Pressure between turbines = 303.84 kPa]

9. A closed-cycle gas turbine is to be used in conjunction with a gas-cooled nuclear reactor. Theworking fluid is helium (cp = 5.19kJ/(kgK) and γ= 1.66).

The layout of the plant consists of two-stage compression with intercooling followed by aheat-exchanger; after leaving the cold side of the heat-exchanger the helium passes throughthe reactor channels and on to the turbine; from the turbine it passes through the hot sideof the heat-exchanger and then a precooler before returning to the compressor inlet. Thefollowing data are applicable:

Compressor and turbine polytropic efficiencies 0.88Temperature at LP compressor inlet 300KPressure at LP compressor inlet 14barCompressor pressure ratios (LP and HP) 2.0Temperature at HP compressor inlet 300KMass flow of helium 180.0kg/sReactor thermal output (heat input to gas turbine) 500.0MWTurbine inlet temperature 1285KPressure loss in precooler and intercooler (each) 0.34barPressure loss in heat-exchanger (each side) 0.27barPressure loss in reactor channels 1.03barHelium temperature at entry to reactor channels 700K

Calculate the power output and thermal efficiency, and the heat-exchanger effectivenessimplied by the data. [214.5MW, 0.429, 0.782]

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problems in chapter 9 cb thermodynamics - lth a steam power plant operates on the reheat rankine...

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