A steam pipe is to transport 200 lbm/s of steam at 200 psia and 600°F. Calculate the minimum diameter this pipe can have so that the steam velocity does not exceed 59 ft/s.

he refrigerant R-134a enters the compressor of a refrigeration machine at a pressure of 140kPa and a temperature of -10°C, and exits at a pressure of 1MPa. The volumetric flow of the refrigerant entering the compressor is 0.23m3/minute. The refrigerant enters the throttling valve at a pressure of 0.95MP and at 30 °C, and exits the evaporator as saturated steam at -18 °C. The adiabatic efficiency of the compressor is 78%. Show the cycle in the T-s diagram. a) Power required to start the compressor b) Calculate the heat withdrawn from the cooled environment in unit time, COPSM=? c) Calculate how much the pressure of the refrigerant drops between the evaporator and the compressor and how much the heat gain is.

A piston cylinder contains 1.25 kg water at 25°C with a constant load on the piston such that the pressure is 300 kPa. A nozzle in a line to the cylinder is opened to enable flow to the outside atmosphere at 100 kPa and 25°C. The process continues until 85% of the initial mass has flowed out. At this point, the temperature of water increased by 10°C. Assume that the process is done in an Water isobaric manner. Write the mass and energy balance equations and calculate the work (kJ) and heat (kJ) involved in the process if the exit velocity is 40 m/s. For compressed liquid, assume the substance is a saturated liquid at the given temperature.

R-134a enters a compressor as a saturated vapor at 80 kPa and exits at a pressure of 400 kPa. If 44 kJ/kg of work is required and 5 kJ/kg of heat is lost to the surroundings. What is the outlet temperature. Round your answer to the nearest whole number.