The air conditioner in a car uses R-134a, and the compressor power input is 1.5 kW, bringing the R-134a from 201.7 kPa to 1200 Kpa by compression. The cold space is a heat exchanger that cools 30 degrees C atmospheric air from the outside down to 10 degrees C and blows it into the car. What is the mass flow rate of the R-134a an ...continues
Calculating the heat transfer rate and the rate that entropy is produced in a gear box.
A gearbox operating under steady state conditions recieves 24 hp along the input shaft and delivers 10hp along the output shaft. The outer surface of the gearbox is at 110F and has an area of 1.4 ft^2. The temperature of the surroundings away from the immediate vicinity of the gearbox is 70 F. For the gear box, determine a) the ...continues
Consider an ideal steam reheat and regenerative cycle where steam leaves a steam gen and enters high pressure turbine at 3 Mpa and T=400 C and is extracted to an open feedwater heater at 0.8 Mpa. The remainder is reheated to 400 C at this pressure which flows to the low pressure turbine stage. The condenser saturation pressure i ...continues
Working with processes of an application to ideal gases.
While its temperature remains constant at 80 degrees F, 2.5lb of a certain gas, whose cp=0.28 and cv=0.2Btu/lb-degreeR, rejects 300 Btu; p1=85psia. Determine (a) V1, V2, p2.
Steam at the rate of 1.75Kg/s+ a absolute press of 700Kpa with unknown dryness is throttled to an absolute press of 50Kpa,its temp is 100 deg C.If the speed of the steam in the pipe is 20.5m/s:Need dryness fraction of steam before throttling,the specific volume of steam before throttling,the diameter of the pipe on the upstream ...continues
A cylinder contains .014 cubic metres of a fluid at 700kpa,having a specific enthalpy of 695kj/kg and a specific volume of .00125 cubic metres per kg.Heat energy is supplied until the volume of the fluid becomes .28cubic metres,the pressure remains constant at 700kpa.If the final specific internal energy of the fluid is 885kj/kg ...continues
A steady flow air compressor compresses 50 lb/min from 14 psia and 80 degrees F to a discharge state at 45 psia and 300 degrees F. Heat departs from the air only via circulating water that enters the jacket at 75 degrees F and leaves at 95 degrees F, circulating at the rate of 15lb/min. Let the frictional losses external to th ...continues
Large stationary brayton cycly gas turbine power plant delivers a powr output of 100MW to an electric generator . Minimum temperature is 300K so T1= 300k max temp is 1600k so T3= 1600k Minimum pressure in the cycle is 100kpa compressor pressure ratio is 14 to 1 so p2/p1 = 14 but turbine efficiency is 85% and compressor efficienc ...continues
Rankine Open Cycle with an Ideal steam reheat cycle where steam enters the high pressure turbine at 3 MPa and 400C and then expands to 0.8 MPa It's then reheated at constant pressure of 0.8 MPa to 400C and expands to 10kPa in the low-pressure turbine. Each turbine stage isentropic efficiency of 85% FWH is open T-S diagram for cy ...continues
Determine the change in entropy of the surrounding.
Liquid H2O at 8 MPa and 40 degrees C is heated reversibly at constant pressure until the temperature reaches 600 degrees C. Determine the change in entropy of the surrounding (universe).
