(2)内能、焓及熵的变化量 The change in Internal Energy, enthalpy and Entropy ch=c dt dg=c dr+ pdv dg=c, dr+d(pv) Sq=dh The amount of heat added to a closed system during a constant pressure process equals to the increase in enthalpy
The amount of heat added to a closed system during a constant pressure process equals to the increase in enthalpy. du = cv dT dh = c p dT q c dT pdv = v + q c dT d( pv) = v + q = dh (2)内能、焓及熵的变化量 The change in Internal Energy, Enthalpy and Entropy
(3 Work done and Heat Transferred dq=c, dr+ pdv dg=c,dr+d(pv) dq= dh The amount of heat added to a closed system during a constant pressure process equals to the increase in enthalpy
The amount of heat added to a closed system during a constant pressure process equals to the increase in enthalpy. q c dT pdv = v + q c dT d( pv) = v + q = dh （3） Work done and Heat Transferred
∞Q=aH 0=m Cpdt During a constant pressure process heat is added or removed and the temperature and volume changes. the volume at the end of the process can be found using the ideal gas law and the work calculated from W=P鸟
Q = dH = 2 1 T T Q m CP dT During a constant pressure process, heat is added or removed and the temperature and volume changes. The volume at the end of the process can be found using the ideal gas law and the work calculated from = − = 2 1 0 p p t w vdp
3.等温压缩和膨胀 Isothermal Compression and Expansion Work +ye T=298K P=101300 Y=02446m3 ↓↓
3. 等温压缩和膨胀 Isothermal Compression and Expansion
(1)过程方程( Process equation) For a constant temperature process, the addition or removal of heat will lead to a change in the ume ressu gas as two graphs above Substitute =c into piV pva 11=P2v2
For a constant temperature process, the addition or removal of heat will lead to a change in the volume and pressure of the gas, as shown on the two graphs above. Substitute into 2 2 2 1 1 1 T p v T p v = T =C 1 1 2 2 p v = p v (1)过程方程 (Process equation)