Start Discovering Solved Questions and Your Course Assignments
TextBooks Included
Active Tutors
Asked Questions
Answered Questions
In 2001, the United States produced 51 percent of its electricity in the amount of 1.878 = 1012 kWh from coal fired power plants.
If the efficiency of a power plant goes up as the low temperature drops why not let the heat rejection go to a refrigerator at say -10oC instead of ambient 20oC
How does the thermal efficiency of an ideal Otto cycle change with the compression ratio of the engine and the specific heat ratio of the working fluid?
How does the COP of a cascade refrigeration system compare to the COP of a simple vapor-compression cycle operating between the same pressure limits?
In a combustion process with decane, C10H22, and air, the dry product mole fractions are 86.9% N2, 1.163% O2, 10.975% CO2 and 0.954% CO
In a combustion chamber, ethane (C2H6) is burned at a rate of 8 kg/h with air that enters the combustion chamber at a rate of 176 kg/h
Hydrogen (H2) is burned with 100 percent excess air that enters the combustion chamber at 90°F, 14.5 psia, and 60 percent relative humidity
How much power is needed to run the fan in Problem 6.29? A household fan of diameter 0.75 m takes air in at 98 kPa, 22oC and delivers it at 105 kPa, 23oC
How is the utilization factor Pu for cogeneration plants defined? Could Pu be unity for a cogeneration plant that does not produce any power?
How is the rpm (revolutions per minute) of an actual four-stroke gasoline engine related to the number of thermodynamic cycles?
Hot exhaust gases leaving an internal combustion engine at 400°C and 150 kPa at a rate of 0.8 kg/s is to be used to produce saturated steam at 200°C
Hydrogen is burned with 150 percent theoretical air during a steady-flow process at a pressure of 1 atm. At what temperature will 98 percent of H2
Hydrogen gas is used in a Carnot cycle having an efficiency of 60% with a low temperature of 300 K. During the heat rejection the pressure changes
Hot combustion gases (assumed to have the properties of air at room temperature) enter a gas turbine at 1 MPa and 1500 K at a rate of 0.1 kg/s
Helium is to be compressed from 120 kPa and 310 K to 700 kPa and 430 K. A heat loss of 20 kJ/kg occurs during the compression process.
Hoover Dam across the Colorado River dams up Lake Mead 200 m higher than the river downstream. The electric generators driven by water-powered turbine
Hot air at 80°C is blown over a 2-m x 4-m flat surface at 30°C. If the convection heat transfer coefficient is 55 W/m2 -c °C
Hot combustion air at 1500 K expands in a polytropic process to a volume 6 times as large with n = 1.5. Find the specific boundary work and the specific heat
Helium gas is compressed from 90 kPa and 30°C to 450 kPa in a reversible, adiabatic process. Determine the final temperature and the work done
Helium gas is compressed steadily from 90 kPa and 25°C to 600 kPa at a rate of 2 kg/min by an adiabatic compressor
Helium in a steel tank is at 40 psia, 540 R with a volume of 4 ft3. It is used to fill a balloon. When the tank pressure drops to 24 psia the flow of helium
Heat is lost through a plane wall steadily at a rate of 800 W. If the inner and outer surface temperatures of the wall are 20°C and 5°C
Heat is lost through a plane wall steadily at a rate of 600 W. If the inner and outer surface temperatures of the wall are 20°C and 5°C, respectively
Give the phase and the missing property of P, T, v and x.
Hot water at 90°C enters a 15-m section of a cast iron pipe whose inner diameter is 4 cm at an average velocity of 0.8 m/s.