TITLE.PM5

298 ENGINEERING THERMODYNAMICS dharm /M-therm/th5-4.pm5 W System Atmosphere at 298 K HE 1 kg water at 25°C to ice at 5°C Q = 4 ...

SECOND LAW OF THERMODYNAMICS AND ENTROPY 299 dharm /M-therm/th5-4.pm5 but when the cycle is not reversible Cycle ∑ F HG I KJ δQ ...

300 ENGINEERING THERMODYNAMICS dharm /M-therm/th5-4.pm5 The processes of a Carnot cycle are (a) two adiabatic and two constant ...

SECOND LAW OF THERMODYNAMICS AND ENTROPY 301 dharm /M-therm/th5-4.pm5 According to Kelvin-Planck’s statement of second law of t ...

302 ENGINEERING THERMODYNAMICS dharm /M-therm/th5-4.pm5 Which of the following is the correct statement? (a) All the reversible ...

SECOND LAW OF THERMODYNAMICS AND ENTROPY 303 dharm /M-therm/th5-4.pm5 A domestic food freezer maintains a temperature of – 15°C ...

304 ENGINEERING THERMODYNAMICS dharm /M-therm/th5-4.pm5 In an air turbine the air expands from 6.8 bar and 430°C to 1.013 bar a ...

SECOND LAW OF THERMODYNAMICS AND ENTROPY 305 dharm /M-therm/th5-4.pm5 In a reversible cycle 100 kJ of heat is received at 500 K ...

6 Availability and Irreversibility 6.1. Available and unavailable energy. 6.2. Available energy referred to a cycle. 6.3. Decrea ...

AVAILABILITY AND IRREVERSIBILITY 307 DHARM M-therm\Th6-1.PM5 For the given values of the source temperature T 1 and sink tempera ...

308 ENGINEERING THERMODYNAMICS DHARM M-therm\Th6-1.PM5 T Unavailable energy s T 0 m Available energy W= Wmax. l–m Ql–m l Fig. 6. ...

AVAILABILITY AND IRREVERSIBILITY 309 DHARM M-therm\Th6-1.PM5 ∆s T T 1 T 0 Q 1 WComp. WExp. Q 2 s Fig. 6.4. Carnot-cycle. Fig. 6. ...

310 ENGINEERING THERMODYNAMICS DHARM M-therm\Th6-1.PM5 ∴ W′ = Q 1 – Q 2 ′ = T 1 ′ ∆s′ – T 0 ∆s′ and W = Q 1 – Q 2 = T 1 ∆s – T 0 ...

AVAILABILITY AND IRREVERSIBILITY 311 DHARM M-therm\Th6-1.PM5 Wengine = Heat supplied – Heat rejected = Q – T 0 (s 1 – s 0 ) ...( ...

312 ENGINEERING THERMODYNAMICS DHARM M-therm\Th6-1.PM5 = T (s 0 – s 1 ) – (u 0 – u 1 ) i.e., W = (u 1 – Ts 1 ) – (u 0 – Ts 0 ) . ...

AVAILABILITY AND IRREVERSIBILITY 313 DHARM M-therm\Th6-1.PM5 = T 0 (s 2 – s 1 ) – Q = T 0 (∆s)system + T 0 (∆s)surr. i.e., i = T ...

314 ENGINEERING THERMODYNAMICS DHARM M-therm\Th6-1.PM5 (i)The entropy produced during heat transfer ; (ii)The decrease in availa ...

AVAILABILITY AND IRREVERSIBILITY 315 DHARM M-therm\Th6-1.PM5 Available energy with the system = (500 – 300) × 14.4 = 2880 kJ ∴ D ...

316 ENGINEERING THERMODYNAMICS DHARM M-therm\Th6-1.PM5 (ii) Heat transferred during cooling (constant pressure) process = m. cp ...

AVAILABILITY AND IRREVERSIBILITY 317 DHARM M-therm\Th6-1.PM5 T 1273 K 773 K 473 K 293 K Gas Steam Increase in unavailable energy ...