Refrigeration Cycles

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 and what is the low temperature heat transfer rate? What is the mass flow rate of air at 10 degrees C?

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 heat transfer rate in BTU/s and b) the rate at which entropy is produced in BTU/(Rs).

Rankine Cycles

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 is 10 Kpa. Determine the thermal efficiency of the cycle and the net specific work. Assume each turbine stage isentropic efficiency to be 99% and assume the FWH is open.

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.

thermo word problem

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 side+ the diameter of the pipe on the downstream side?