Chapter 8, Problem 8.13P

(2) Describe briefly why the following statements are wrong. (a) "Hot cup of coffee becoming cold spontaneously is an entropy-decreasing process. So the law of entropy increase can be violated." (b) “Air conditioners require bulky external unit, exhausting heat to outside. With the technology constantly advancing, external unit will be eliminated in the future."

The A value is 8

A- For the cycle shown in the (P-V) diagram, a 0.1 kg of air is suffered from three process. Find the net work output, the net heat transfer, and the net entropy change if the air is contained in a piston-cylinder arrangement. P (kPa) 800 100 0.08 T=const. V (m

ASJDBNLAHBADJBSFJDB Answer in kJ/kg Suppose that a power plant operates on a Carnot vapor cycle and uses water as the working substance. Saturated liquid water enters the boiler at a pressure of 10 MPa and leaves as saturated water vapor. Then it enters the steam turbine and leaves as saturated mixture at 20 kPa. Determine the heat added to the working substance in the boiler.

Find the entropy production and determine if the cycle operates irreverisbly, reverisbly, or impossibly. A refrigeration cycle operates between the freezer compartment at 268K and the ambient air at 295K. The rate of heat transfer from the freezer compartment is 8000 kJ/h and the power input for the cycle is 3200 kJ/h. Determine the entropy production for this cycle in kJ/K·h (do not convert h to s). Enter the answer without units, but with a minus sign if applicable. This cycle operates     irreversibly     reversibly     impossibly.

The turbine and compressor are adiabatic. Determine for this cycle, whether it is Perpetual Motion Machine and its kind? fuel combustion chamber 5 bar turbine electricity 1 bar compressor 5 bar OYes, PMM 1 O Yes, PMM 2 No

All equilibrium reversible processes have a total entropy to be equal to______

In a steam power plant, dry saturated steam enters the turbine at a pressure of 40 bar and exits the turbine at a pressure of 0.1 bar. The turbine has an isentropic efficiency of 90 %, and the condensate pump has an isentropic efficiency of 85 %. The water/steam mass flow rate through the plant is 200 kg/s, and all changes in kinetic and potential energy are negligible. Using this information, determine: a) The power output of the turbine, in MW. b) The power required by the pump, in MW.

Thermodynamics question: Isentropic turbine vs. un-insulated turbine: True or False 1.)The un-insulated turbine will produce more work  2.)The isentropic turbine will contribute more entropy to the environment  3.)The efficiency of the isentropic turbine will always be greater than that of the un-insulated turbine  4.)The un-insulated turbine will produce no work