The working gas of a thermodynamic cycle is a diatomic gas (assume constant specific heats.) The gas originally starts at 100kPa, 4m ³ and 27° C. It undergoes a four-step process --- • Process A-B: The gas is compressed at constant temperature to one-quarter of its original volume. • Process B-C: The volume of the gas is then doubled at constant pressure. • Process C-D: The gas then undergoes an adiabatic expansion. • Process D-A: The gas then undergoes a constant volume process back to its original state a) Make a table of the temperature, pressure, volume, internal energy, enthalpy, entropy and quality factor (T, P, V, U, H & S) at the start of each process. b) Make a table of the change in internal energy, heat flow, work done, change in enthalpy, and change in entropy (AU, Q, W, AH & AS) during each leg of the cycle. c) Draw well-labelled P-V & T-S diagrams (indicating lines of constant temperature, heat flow, work, etc.) d) Calculate the thermal efficiency of the cycle.

2. Using the steam tables, determine the specific enthalpy, specific volume and specific enthalpy for steam at 2800 KPa and at a temperature of 300 C. a. The steam in question 2 above is taken through a process that makes it expand isentropically to a pressure of 1650 KPa. What is the final temperature, specific enthalpy, specific volume and specific entropy of the steam in this new state? b. What is the change in specific enthalpy, specific volume, temperature and specific entropy?

(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."

A water pump is to be purchased for a mechanical boiler system. The cost is 20,000 TL with a depreciation rate of 10% for a service life of 10 years. Determine the depreciation of the compressor for the second year using the declining-balance depreciation method and find the correct answer stated below.