Calculate the entropy production for the piston-cylinderpower producing cycle you analyzed in Problem 1. Consider that allheat flows into the system come from a constant temperature sourceof 1800K and that all heat flows out of the system are to aconstant temperature of 250 K. Will this cycle operate? Whichprocess should be altered in order to improve the efficiency of thesystem or to make it work?

Problem 1:

. A simple, effective electric load leveling technique is touse excess produced electricity to pump water into a hill topreservoirs during off peak hours and then discharging it duringpeak electrical demand periods. This simple, old style energystorage concept is increasingly being used to have a more effectivepower generation system. The drawback to this technique is that onehas to operate in a hilly or mountainous region. Someone hassuggested an alternative that can be applied at any location. Inthis alternative, a reclaimed concrete mass is to be raised usingexcess generated electrical power. The density of the reclaimedconcrete is the same as concrete. During excess electrical powerproduction periods, this mass will be raised using a pulley-motorcombination. During the peak power demands the mass will be loweredusing a pulley-electric generator to produce power. The effect ofthe friction in the pulley is a tangential force that operates atthe outer pulley circumference that interfaces with the cable. Thisforce, Ffric, is proportional to the mass being lifted by thefollowing relationship: Ffric = 0.008(lifted weight) [note: theforce is proportional to the weight, a force, not the mass]. Thereis a similar loss in the cable-winding pulley, but the relationshipis Fpulley = 0.003(lifted weight). Frictional losses ultimately areconverted to heat losses to the environment. The lifting towercontaining this mass has an above ground height limit of 30 m and abelow ground depth limit of 30 m. The device can be considered tobe isothermal during these processes.