Questions and Answers of Thermodynamics Concepts And Applications

A booster pump is used to move water from the basement equipment room to the twelfth floor of an apartment building at the rate of 363 kg/min. The elevation change is 40 m between the basement and
The discharge of a pump is 3 m above the inlet. Water enters at a pressure of 138 kPa and leaves at a pressure of 1.38 MPa. The specific volume of the water is 0.001 m3/kg. If there is no heat
A centrifugal pump receives liquid nitrogen at –340 F at the rate of 100 lbm/s. The nitrogen enters the pump as a liquid at 15 psia. The discharge pressure is 400 psia. Estimate the minimum size of
Water enters a pump at 10 kPa and 35° C and leaves at 5 MPa. For reversible adiabatic operation, calculate the work done per unit mass of working fluid and the exit temperature.
Products of combustion enter the turbine section of a jet engine at 1200 K with a flow rate of 63.5 kg/s. Determine the turbine outlet temperature if the turbine delivers 28.2 MW to drive the
A compressor uses air as the working fluid. The air enters at 101 kPa and 16° C and exits at 1.86 MPa and 775° C. What is the compressor isentropic efficiency?
Air is compressed from 101.3 kPa and 15° C to 700 kPa. Determine the power required to process 0.3 m3/min at the outlet if the operation is (a) Polytropic (n = 1.25) (b) Isentropic.
Consider the situation described in Example 8.74; however, imagine that the turbine is now located at one-half z1 and that the discharge pipe is extended down to z2 (= 0), the original discharge
Air at 50 psia and 90 F flows at the rate of 1.6 lbm/s through an insulated ideal turbine. If the air delivers 11.5 hp to the turbine blades, at what temperature does the air leave the turbine? Δz =
A 200-ft3/min flow of air at 14.7 psia and 60 F enters a fan with negligible inlet velocity. The fan discharge duct has a cross-sectional area of 3 ft2. The process across the fan is isentropic
A fan is used to provide fresh air to the welding area in an industrial plant. The fan takes in outside air at 27° C and 101 kPa at a rate of 34 m3/min with negligible inlet velocity. In the 0.93-m2
Water flowing at 950,000 liters/min enters a pump in a power plant at 150° C and 0.5 MPa. The pump increases the water pressure to 10 MPa (v = 0.063 m3/kg).Determine (a) The mass flow rate
The elevation change available at the Grand Coulee Dam is 330 ft. What is the maximum possible power per unit mass flow rate that a hydro turbine can produce at this site? What mass flow rate of
Air enters a multistage compressor of a jet engine at 50 kPa and 270 K with a flow rate of 40 kg/s. The compressor has an overall pressure ratio of 20:1. Determine the power required to drive the
Solve Problem 8.59 using EES or other software.Problem 8.59Air enters a multistage compressor of a jet engine at 50 kPa and 270 K with a flow rate of 40 kg/s. The compressor has an overall pressure
A turbine receives steam at a pressure of 1000 psia and 1000 F and exhausts the steam at 3 psia. The velocity of the steam at the inlet is 50 ft/s. At the outlet, which is 10 ft higher, the velocity
Solve Problem 8.62 using EES or other software.Problem 8.62Determine the power required to is entropically pump 25 kg/s of water from saturated liquid at 50 kPa to 3.0 MPa. Assume incompressible flow.
Using your computer solution from Problem 8.63, vary the outflow pressure from 300 kPa to 6 MPa. Plot the power as a function of the outflow pressure. Put pressure on the abscissa (x-axis) of
Determine the flow rate required to produce 25 MW of shaft power from a steam turbine in which the steam enters at MPa and 720 K and exits at 5 kPa for the following cases: (a) An ideal
The steam flow rate in a power plant is 650,000 lbm/hr. The steam enters the turbine at 500 psia and 1000 F. The turbine exhaust pressure is 1.0 psia and the quality of the exiting steam is 0.925.
Steam expands in an ideal adiabatic turbine from 5000 kPa and 400°C to 40 kPa. Determine the turbine power output if the steam is supplied at a rate of 136 kg/s.
A small adiabatic steam turbine operating at part load produces 100 hp. The mass flow rate is 1350 lbm/hr. Steam at 450 F and 200 psia is throttled to 160 psia before entering the turbine. The
A shell-and-tube heat exchanger uses 6800 kg/hr of water (cp = 4.18 kJ/kg· °C) entering at 25° C to cool 18,000 kg/h of oil (cp = 2.9 kJ/kg· °C) entering at 100° C. For a water outflow
A counter flow heat exchanger uses 6500 kg/hr of water (cp ≌ 4.18 kJ/kg · °C) entering at 25° C to cool 13,000 kg/hr of oil (cp = 2.09 kJ/kg · °C) entering at 100° C. If the
Steam flows through a turbine in a nuclear power plant at 1,230,000 lbm/hr. The turbine inlet conditions are 500 psia and 1200 F, and the turbine outlet pressure is 5 psia. Determine the maximum
Air at 50 psia and 90 F flows through an expander (like a turbine) at the rate of 1.6 lbm/s to an exit pressure of 14.7 psia. (a) What is the minimum temperature attainable at the expander exit
For the turbine in Problem 8.81, how does the isentropic efficiency change if the exit pressure is decreased to 35 kPa with the same outflow quality of 0.92?Problem 8.81Steam enters a turbine as a
A high-speed turbine produces 1 hp while operating on compressed air. The inlet and outlet conditions are 70 psia and 85 F and 14.7 psia and –50 F, respectively. Assume changes in kinetic and
Solve Problem 8.86 using EES or other software.Problem 8.86Steam at 600° C and 12 MPa with a flow rate of 65 kg/s enters an isentropic turbine. What is the power output from the turbine if the
Steam with a flow rate of 65 kg/s enters an isentropic turbine at 12 MPa and exits at 70 kPa. Using your computer solution from Problem 8.87, vary the inflow temperature from 500° C to 650° C. Plot
In the production of orange juice, it is desired to heat the juice from 4° C to 93° C in a tubular heat exchanger. To accomplish this task, saturated steam enters the outer tube of the heat
Water enters a heat exchanger at 180 F and 20 psia and leaves at 160 F and 19.8 psia. Air enters the heat exchanger at 70 F and 15 psia and leaves at 100 F and 14.7 psia. The mass flow rate of the
Water is heated by air in a heat exchanger. The water enters at 420 K and 0.3 MPa and leaves at 560 K and 0.3 MPa. The mass flow rate of the water is 1.2 kg/s. The air enters at 620 K and 0.1 MPa at
A steam condenser is made with 125 tube paths each having an inside diameter of 11.7 mm. Cooling water (cp = 4.18 kJ/kg · °C) enters the tubes at 42° C with an average velocity of 1.37 m/s through
A one-shell-pass, two-tube-pass heat exchanger is to be used to cool ethylene glycol with water. The ethylene glycol (cp = 2.505 kJ/kg · °C) enters at 85° C flowing at 1 kg/s; the water (cp=
A one-shell-pass, one-tube-pass, counterflow heat exchanger is used to cool oil (cp = 1.811 kJ/kg · °C). The oil enters the shell at 120° C flowing at 15,000 kg/hr. Cooling water (cp= 4.18 kJ/kg
Saturated steam condenses in a horizontal steam condenser at a pressure of 14 kPa. Each of the 180 parallel tubes in the condenser has an inside diameter of 12.6 mm and an average liquid water
A 3.1-lbm mass of air is trapped in a cylinder and compressed isothermally at 85 F from 15 psia to 100 psia. During the compression, 412 Btu of energy is removed in a heat-transfer process.
A steam condenser is made with 115 parallel tubes each having an inner diameter of 0.584 inches. The cooling water (cp = 1.0 Btu/lbm · F) enters the tubes at 70 F with an average velocity of 5
Consider a piston–cylinder assembly containing 0.15 kg of N2 initially at 515 K and 800 kPa (state 1). The piston is such that the final pressure of the air is 175 kPa. The process occurs at a
Initially, 0.5 kg of dry, saturated steam at 115° C is contained inside a spherical elastic balloon whose internal pressure is proportional its diameter. Heat is then transferred to the steam
Consider the following four (A–D) closed thermodynamic systems at an instant. The systems consist of a single-phase substance.Answer the questions posed for the following scenarios:A. At a
Pulverized coal particles at 300 K are injected into hot furnace gases at 1500 K. Estimate the initial heating rate of a 70μm-diameter particle. Express your result in kelvins per second. TXhe
Dry, saturated steam from a turbine enters a condenser at 4 kPa and exits as saturated liquid, also at 4 kPa. In the condenser, energy is removed from the steam by heat transfer to a stream of lake
Air is contained in a piston–cylinder assembly at 2 MPa and 400 K (state 1). The 0.15-m-diameter piston is locked in place by stops at the 0.2-m position, and a 2-kg steel block sits on top of the
Consider a piston–cylinder assembly containing 0.12 kg of nitrogen initially at 700 K and 300 kPa (state 1). The piston moves such that the final volume of the nitrogen (state 2) is three times
Consider a piston–cylinder assembly containing 0.10 kg of air initially at 300 K and 300 kPa (state 1). The piston moves such that 35.9 kJ of work is done on the air by the surroundings. The
Consider a piston–cylinder assembly containing 0.25 kg of air initially at 750 K and 200 kPa (state 1). The piston moves such that 20 kJ of work is done on the air by the surroundings. The process
Consider a piston–cylinder assembly containing 0.14 kg of air initially at 500 K and 250 kPa (state 1). The piston moves such that 5 kJ of work is done on the air by the surroundings. The process
Consider a piston–cylinder assembly containing 0.08 kg of air initially at 950 K and 400 kPa (state 1). The piston moves such that 30 kJ of work is done by the air on the surroundings. The process
Consider a piston–cylinder assembly containing 0.09 kg of air initially at 600 K and 350 kPa (state 1). The piston moves such that 18 kJ of work is done by the air on the surroundings. The process
Consider a thermodynamic system consisting 3 kg of air. The air is compressed frictionlessly and adiabatically from 100 kPa and 300 K to 400 kPa. The process follows the path PVγ = constant (= P1V1
Consider a piston–cylinder assembly containing 0.10 kg of N2 initially at 425 K and 150 kPa (state 1). The piston moves such that the final pressure of the air is 350 kPa. The process occurs at
Saturated steam is contained in a sealed rigid tank at 600 K (state 1). Energy is removed from the steam by heat transfer until a temperature of 400 K (state 2) is reached. Plot the process in P–v
Consider a piston–cylinder assembly containing 0.85 kg of air initially at 400 K and 620 kPa (state 1). The piston such that the final pressure of the air is 300 kPa. The process occurs
While trapped in a cylinder, 2.27 kg of air is compressed isothermally (a water jacket being used around the cylinder to maintain constant temperature) from initial conditions of 101 kPa and 16°C to
Consider a piston–cylinder assembly containing 0.09 kg of steam having a quality of 0.9 at 500 kPa (state 1). Energy added to the steam by a heat interaction at constant pressure until a
A balloon at sea level contains 2 kg of helium at 30° C and 1 atm. The balloon then rises to 1500m above sea level. At this height, the helium temperature is 6° C. Determine the change in internal
Initially, 1 kg of air at 101 kPa and 700 K is contained in a rigid tank. The tank is not insulated and cools down, as result of heat transfer to the atmosphere (Tatm = 25° C, Patm = 101 kPa),
Air, initially at 205°C and 3.45 MPa, expands isothermally in a piston–cylinder device until its volume is 100 times larger than its initial volume. Determine the following:A. The increase in
Consider a piston–cylinder assembly containing 0.1 kg of saturated steam at 300 kPa (state 1). Energy is added the steam by a heat interaction at constant pressure until a temperature of 600
Superheated steam is contained in a sealed rigid tank at 600 K and 0.3 MPa (state 1). Energy is removed from the steam by heat transfer until a temperature of 350 K (state 2) is reached. Plot the
Consider a piston–cylinder assembly containing 0.125 kg of wet steam with a quality of 0.45 at 300 kPa (state 1). Energy is added to the steam at constant temperature by a heat interaction until
Consider a piston–cylinder assembly containing 0.25 kg of wet steam with a quality of 0.85 at 400 kPa (state 1). Energy is removed from the steam at constant temperature by a heat interaction until
Saturated steam is contained in a sealed rigid tank at 500 K (state 1). Energy is removed from the steam by heat transfer until a temperature of 350 K (state 2) is reached. Determine the heat
Consider a piston–cylinder assembly containing 0.12 kg of superheated steam at 700 kPa and 800 K (state 1). Energy is removed from the steam by heat transfer until a temperature of 400 K is reached
Steam (13.2 kg) at 1.5 MPa with an 80% quality comprises a thermodynamic system. The steam is heated in a frictionless process until the temperature is 540 K.A. Calculate the heat transfer (kJ) if
Consider 1.1 kg of steam initially at 0.15 MPa and 400 K in a closed, rigid container. This steam is heated to 440 K. Determine the amount of heat added to the system in kJ.
Initially, 1 kg of water (liquid and/or vapor) at 0.1 MPa is contained in a rigid 1.5-m3 tank. The H2O is then heated and equilibrates at 300° C. Determine the final pressure (MPa) and the heat
Old homes are sometimes heated with so-called steam radiators. In operation, steam flows through the metal radiator causing the metal surface to become hot, which, in turn, results in heat transfer
An 2.27-m3 steam boiler initially contains 1.7025m3 of liquid water and 0.5675m3 of water vapor in equilibrium at 100 kPa. The boiler is fired up and the liquid and vapor in the boiler are
The temperature of 150 liters of liquid water, initially at 10°C, is increased to 60°C by a 2500-W electric heater.A. Determine the total energy (MJ) required.B. Determine the length of time (hr)
Write out in words the precise meaning of the following symbols. Be very specific, using appropriate adjectives as needed. Also provide the usual SI units associated with the quantities. If the
A piston–cylinder assembly initially contains 0.45 kg of water at 8.0 MPa and a quality of 0.25. The water is then heated to a temperature of 760 K. The piston moves freely and maintains the
One kilogram of water (liquid and/or vapor) at 140 kPa is contained in a piston cylinder device. The initial volume is 0.7m3 The water is then heated until its temperature reaches 700 K. The piston
A piston–cylinder device has an initial volume of 0.003m3 and contains dry, saturated water vapor at 200°C. A connecting rod attached to the piston and transfers work to (or from) the
Initially, 0.45 kg of steam at 0.7 MPa with a quality of 0.90 is held in an adiabatic cylinder fitted with a freely floating piston and paddle wheel. The paddle wheel is then turned on for 1
A rigid cylinder fitted with a freely floating piston is divided into two parts (A and B) by a rigid metal partition. Initially, part contains 0.91 kg of water liquid and/or vapor) at 1.7 MPa
Compressed natural gas (CNG) is contained in a rigid tank near room temperature (300 K) and with a pressure of 6.75 MPa. CNG is cooled until it just starts to condense. Assuming the CNG can be
A small propane tank (V = 0.0185 m3), used to fuel a barbeque grill, is approximately half full and contains 10 pounds (4.55 kg) of propane. A fire breaks out enveloping the tank in flames. There is
A 1-kg piece of iron, initially at 700° C, is quenched by dropping it into an insulated tank containing 2 kg of liquid water. The initial temperature of the water is 20° C.Determine the final
A closed, rigid steel tank has an inner volume of 0.02832m3 and has a mass of 22.7 kg when empty. Initially, the tank contains 0.45 kg of water (liquid plus vapor), and the tank and the water are
The inlet and outlet streams of an open system are described by the following information.If the net work rate out is 4.101 kW, what is the heat-transfer rate? Velocity Elevation Enthalpy Mass
A car battery is charged by applying a current of 40A at 12 V for 30 min. During the charging process, there is a heat transfer of 200 from the battery to the surroundings. Determine the
An electric circuit consists of a 12-V storage battery, a 10-oh resistor, and an electric motor connected in parallel. If the motor produces 100mW of power, estimate the rate of energy depletion from
Which of the following are true statements? Justify your responses, true or false, with a sentence or two.cA. Enthalpy appears in the conservation of energy equation for open systems because open
Consider a waterfall having a drop of 84.7 m.A. Determine the specific potential energy (J/kg) of the water at the top of the waterfall with respect to the base of the waterfall.B. Assuming no energy
Without reference to the text, write a symbolic expression for the conservation of energy (the first law of thermodynamics) for a open system having a single inlet and a single outlet. Assume steady
Repeat Problem 5.82, eliminating the assumption of a steady state.Problem 5.82Without reference to the text, write a symbolic expression for the conservation of energy (the first law of
Explain the origin of enthalpy in the expression of the conservation of energy for an open system.
Show in excruciating detail that the units associated with the term V2/2 are J/kg.
Mass flows through a control volume (open system) at 1 kg/s. The enthalpy, velocity, and elevation at entrance are 200 kJ/kg, 30 m/s, and 100 m, respectively. At the exit, these quantities are 198
Saturated steam at 0.3 MPa flows through a 5.08-cm-inside-diameter pipe at a rate of 700 kg/hr. Determine the specific kinetic energy of the steam in kJ/kg.
Steam at 580 K and 1.5 MPa enters a well-insulated steady-state device through a standard 3-inch pipeline (inside diameter = 3.068 in) at 10 ft/s. The exhaust from the device flows through a standard
As a fluid flows steadily past a turbine blade with friction present, the fluid velocity drops from 400 m/s to 100 m/s while the fluid enthalpy increases by 25 kJ/kg. Assuming the process ais
An ideal gas passes steadily through a device that increases the gas velocity from 5m/s to 300 m/s without transfer of heat or work.A. Determine the increase in specific enthalpy (kJ/kg) of the
Quite some time ago, Frank Lloyd Wright designed a one-mile-high building. Suppose that, in such a building, steam for the heating system enters a pipe at ground level as dry, saturated vapor at 200
Water (assumed to be incompressible) is pumped at a constant rate of 22.7 kg/min through a pipeline that has an internal diameter of 50.8 mm. The pipe discharges through a nozzle that has a diameter
The manager of an amusement park at the bottom of Niagara Falls wants to install a water turbine to produce 100 kW. (assumed to be incompressible) would enter the pipeline leading to the
Water at 5 MPa and 400 K enters the steam-generating unit of a power plant and leaves the unit as steam at 5 MPa and 1000 K. The water mass flow rate is 14,000 kg/hr. Determine the capacity of the

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