2013-2-27 Overview:Laws of Thermodynamics First law of thermodynamics an expression of conservation of energy principle >En-Eout=△Esystem >for closed system: Q=△U+W 6Q=dU+6W(differential form) (conservation of energy principle:energy can neither be created,nor be destroyed;it can change from one form to another,but the total amount of energy remains constant) The first kind of perpetual motion machine is impossible! Overview:Laws of Thermodynamics Second law of thermodynamics >Kelvin-Planck statement:It is impossible for any device that operates on a cycle to receive heat from a single reservoir and produce a net amount of work >Clausius statement:It is impossible to construct a device that operates in a cycle and produces no effect other than the transfer of heat from a lower-temperature body to a higher- temperature body. The second kind of perpetual motion machine is impossible 6
2013-2-27 6 First law of thermodynamics an expression of conservation of energy principle ¾Ein – Eout = △Esystem ¾for closed system： Q=△U+W δQ=dU+δW (differential form) (conservation of energy principle: energy can neither be created, nor be destroyed; it can change from one form to another, but the total amount of energy remains constant) 11 The first kind of perpetual motion machine is impossible! Overview: Laws of Thermodynamics Second law of thermodynamics ¾Kelvin-Planck statement: It is impossible for any device that operates on a cycle to receive heat from a single reservoir and produce a net amount of work ¾Clausius statement: It is impossible to construct a device that operates in a cycle and produces no effect other than the transfer of heat from a lower-temperature body to a highertemperature body. 12 Overview: Laws of Thermodynamics The second kind of perpetual motion machine is impossible!
2013-2-27 Overview:Laws of Thermodynamics Third law of thermodynamics >The entropy of a pure crystalline substance at absolute zero temperature is zero >The impossibility of reaching absolute zero of temperature (在绝对零度，任何完美晶体的熵为零：绝对零度 不可能达到) Overview:Laws of Thermodynamics ·Zeroth law of thermodynamics(热力学第零定律) ·First law of thermodynamics(热力学第一定律) ·Second law of thermodynamics(热力学第二定律) ·Third law of thermodynamics(热力学第三定律) ·Camnot Principles(卡诺定理；孤立系统熵(entropy) 增原理 Carnot cycle,Rankine cycle 7
2013-2-27 7 Third law of thermodynamics ¾The entropy of a pure crystalline substance at absolute zero temperature is zero ¾The impossibility of reaching absolute zero of temperature （在绝对零度，任何完美晶体的熵为零；绝对零度 不可能达到 ） 13 Overview: Laws of Thermodynamics • Zeroth law of thermodynamics (热力学第零定律) • First law of thermodynamics (热力学第一定律) • Second law of thermodynamics (热力学第二定律) • Third law of thermodynamics (热力学第三定律) • Carnot Principles (卡诺定理); 孤立系统熵(entropy) 增原理 • Carnot cycle, Rankine cycle 14 Overview: Laws of Thermodynamics
2013-2-27 Overview:History of Thermodynamics First successful steam engine build by Watt? Overview:History of Thermodynamics First successful steam engine designed by Thomas saver y11697 patented a steam-powered pump he called the MnFrid) 1as Newcomen created the first practical steam eng James Watt improved in 1763 to 1784 (75%less coal) 8
2013-2-27 8 First successful steam engine build by ? Watt? ??? 15 Overview: History of Thermodynamics • First successful steam engine designed by Thomas Savery (1697 patented a steam-powered pump he called the Miner's Friend ) • Thomas Newcomen created the first practical steam engine in 1712. • James Watt improved in 1763 to 1784 (75% less coal) 16 Animation of a schematic Newcomen steam engine. – Steam is shown pink and water is blue. – Valves move from open (green) to closed (red) 汽缸/活塞 水箱 Overview: History of Thermodynamics
2013-2-27 Overview:History of Thermodynamics in1849. William Rankine/朝情（1820-1872： -Rudolph Clausius/克劳体新(1822.1888 3 adiCamo-卡话(1796-1832 James Prescott Joule焦耳(1818-1889) Overview:History of Thermodynamics 。andseondlasahemonmes6megan19ss.tomvoe Rudolph C1 ausius/克劳修斯(1822-1888 Sadi Camot-咔诸(1796-1832 James Prescott Joule/焦耳(1818-1889 18 9
2013-2-27 9 First and second laws of thermodynamics emerged in 1850s, from works of – Lord Kelvin/开尔文 (1824-1907): developed the Kelvin scale of absolute temperature measurement; firstly use thermodynamics in 1849. – William Rankine /朗肯 (1820-1872) : – Rudolph Clausius/克劳修斯 (1822-1888): Sadi Carnot/卡诺 (1796 –1832) James Prescott Joule /焦耳 (1818-1889) 17 Overview: History of Thermodynamics First and second laws of thermodynamics emerged in 1950s, from works of – Lord Kelvin/开尔文 (1824-1907): developed the Kelvin scale of absolute temperature measurement; firstly use thermodynamics in 1849. – William Rankine /朗肯 (1820-1872) : developed a complete theory of the steam engine and indeed of all heat engines. Write first thermodynamic textbook in 1859. – Rudolph Clausius/克劳修斯 (1822-1888): Sadi Carnot/卡诺 (1796 –1832) James Prescott Joule /焦耳 (1818-1889) 18 Overview: History of Thermodynamics
2013-2-27 Overview:History of Thermodynamics 。andceondlas6Mhemodnsmeemegen19s0a.tomote ord K cduced the concept of entropy. adi Camot卡话(1796-1832 James Prescott Joule/焦耳(1818-1889) Overview:History of Thermodynamics standeandlashemodnamesemergen195a.tiomvoe ot of entropy retica nea James Prescott Joule/焦耳(1818-1889) 10
2013-2-27 10 First and second laws of thermodynamics emerged in 1950s, from works of – Lord Kelvin/开尔文 (1824-1907): developed the Kelvin scale of absolute temperature measurement; firstly use thermodynamics in 1849. – William Rankine /朗肯 (1820-1872) : developed a complete theory of the steam engine and indeed of all heat engines. Write first thermodynamic textbook in 1859. – Rudolph Clausius/克劳修斯 (1822-1888): in 1850, first stated the basic ideas of the second law of thermodynamics. In 1865 he introduced the concept of entropy. Sadi Carnot/卡诺 (1796 –1832) James Prescott Joule /焦耳 (1818-1889) 19 Overview: History of Thermodynamics First and second laws of thermodynamics emerged in 1950s, from works of – Lord Kelvin/开尔文 (1824-1907): developed the Kelvin scale of absolute temperature measurement; firstly use thermodynamics in 1849. – William Rankine /朗肯 (1820-1872) : developed a complete theory of the steam engine and indeed of all heat engines. Write first thermodynamic textbook in 1859. – Rudolph Clausius/克劳修斯 (1822-1888): in 1850, first stated the basic ideas of the second law of thermodynamics. In 1865 he introduced the concept of entropy. Sadi Carnot/卡诺 (1796 –1832) gave the first successful theoretical account of heat engines, now known as the Carnot cycle, laying the foundations of the second law of thermodynamics. Others like: Carnot efficiency, Carnot heat engine. James Prescott Joule /焦耳 (1818-1889) 20 Overview: History of Thermodynamics