A refrigeration cycle operating between two reservoirs receives energy QC from a cold reservoir at TC = 250 K and rejects energy QH to a hot reservoir TH = 350 K. For each of the following cases determine whether the cycle operates reversibly, irreversibly, or is impossible: (a) QC = 1500 kJ, QH = 2200 kJ, (b) QC = 1500 kJ, Wcycle = 120 kJ, (c) QH = 1600 kJ, Wcycle = 500 kJ, (d) COP = 6.

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk