Chapter 6, Problem 6.149EP

: Is perfect heat engine and perfect refrigerator exist in term of entropy

An air conditioner using refrigerant 134a as work fluid It is used to keep the temperature of a room at 23 ° C by giving heat to the environment. The house from the walls and heat gain from windows is 250 kJ / min ; 900 W of heat from computer, TV and lamps to the room spreads. The refrigerant is 100 L / min in the form of saturated vapor at 400 kPa pressure to the compressor entering with flow and it left from the compressor 1200 kPa pressure and 70 ° C. a) real COP value b) max COP value c) Calculate the min volumetric flow rate for the refrigerant can have for the same compressor inlet and outlet conditions

There are two source "X" and "Y" supplying energy with rate of 12345 kJ/min at 290°C and 123456 kJ/min at 65°C respectively. Out of these two source (X or Y) you recomend to supply energy to reversible heat engine for generating work if sink temperature is 29°C?

A Carnot Engine receives 250 KJ/s of heat form a heat-source reservoir at 525ºC and rejects heat to a heat-sink reservoir at 50ºC. What is the power developed and heat rejected?

I need the answer as soon as possible

A solar collector absorbed 40W/m2 heat from the atmosphere. This is equal to the convection brought by air for drying purpose. If the temperature of the air is 40C while the solar collector area's temperature is 80C and neglecting effect of radiation, find the convective heat transfer coefficient.

is q in < q out in power cycles, heat pump cycles, or refrigeration cycles?

An indoor heater operating on the Carnot cycle is warming the house up at a rate of 30 kJ/s to maintain the indoor temperature at 72 ºF. What is the power operating the heater if the outdoor temperature is 30 ºF

A turbine receives 8 kg/s of air at 9 MPa, 677 C and 60 m/s (pressure, temperature and velocity). It discharges the air at a temperature of 77 C and a velocity of 15 m/s. In addition, there is heat transfer from the turbine to the surroundings for 150 kW. Find the power produced by the turbine in kW and its isentropic efficiency. You may use specific heats at the average temperature.