T T 2 add heat (molecular motion (molecular motion)
热力学能的说明 ●热力学能是状态量 state property ●U:广延参数[kJ] ●u:比参数[kJ/kg ●热力学能总以变化量出现,热力学能零点人为定义
热力学能的说明 ⚫ 热力学能是状态量 state property ⚫ U : 广延参数 [ kJ ] ⚫ u : 比参数 [kJ/kg] ⚫ 热力学能总以变化量出现，热力学能零点人为定义
2.宏观储存能:动能和势能 Macroscopic energy-u-kinetic energy and potential energy They are related to some outside reference frame Kinetic energy is the energy a system possesses as a result of its motion relative to some reference frame it is denoted as Eke. C ke Potential energy is the energy a system possesses as a result of its elevation in a gravitational field E= mgz
2.宏观储存能：动能和势能 Macroscopic energy---kinetic energy and potential energy They are related to some outside reference frame。 Kinetic energy is the energy a system possesses as a result of its motion relative to some reference frame. It is denoted as Eke... Potential energy is the energy a system possesses as a result of its elevation in a gravitational field. 2 2 mc Eke = E mgz p =
3系统的总能量〔 Total energy) nc E=U+E+e =u+ t mez 2 On a unit mass basis 2 e= u t eke ten =ut c +8z
On a unit mass basis mgz mc E = U + Eke + Ep = U + + 2 2 e u e e u c gz = + ke + p = + + 2 2 1 3.系统的总能量 (Total energy）
83.2 Energy transfer by Heat Work and Mass (热量、功量及质量引起的能量传递-传递中的能量) 1传热和热量( Heat transfer and heat) 热量是以温差为推动力时,系统与外界之间传递的能量 Heat is energy interaction between a system and its surroundings if its driving force is temperature difference only (1)热量是传递中的能量( Heat is energy in transition.) Eg. The baked potato contains energy, this energy is heat transfer only as it passes through the skin of potato to reach the air. Once in the surroundings, the transferred heat becomes part of the internal energy of the surroundings, or vise versa
⒈传热和热量（Heat transfer and heat） 热量是以温差为推动力时，系统与外界之间传递的能量 Heat is energy interaction between a system and its surroundings if its driving force is temperature difference only. (1) 热量是传递中的能量（Heat is energy in transition. ） Eg. The baked potato contains energy, this energy is heat transfer only as it passes through the skin of potato to reach the air. Once in the surroundings, the transferred heat becomes part of the internal energy of the surroundings, or vise versa. §3.2 Energy transfer by Heat, Work and Mass (热量、功量及质量引起的能量传递------传递中的能量）