Chapter 8 Production of Power from Heat
Chapter 8 Chapter 8 Production of Power from Heat Production of Power from Heat
Chapter 8 Production of Power from Heat content 8.1 The steam power plant 8.2 Internal-Combustion Engines 8.3 Jet Engines;Rocket Engines
Chapter 8 Chapter 8 Production of Power from Heat Production of Power from Heat content 8.1 The steam power plant 8.3 Jet Engines; Rocket Engines 8.2 Internal-Combustion Engines
Introduction Forms of energy used by mankind Energy from the sun The kinetic energy associated with atmospheric winds The potential energy of tides Hydroelectric power Chemical energy of fuels Nuclear energy 且的：研究循环中热、功转换的效果及其影响因素，探求提高能量转换效果的途径。 内容： .讨论蒸汽动力循环的热效率、功以及循环中各工质状态的变化 2制冷循环的热力学分析 要求：掌握工作原理、工质状态变化、能量转换计算、能量转换效果热力学分析
目的：研究循环中热、功转换的效果及其影响因素，探求提高能量转换效果的途径。 内容： 1.讨论蒸汽动力循环的热效率、功以及循环中各工质状态的变化 2.制冷循环的热力学分析 要求：掌握工作原理、工质状态变化、能量转换计算、能量转换效果热力学分析 Introduction Forms of energy used by mankind The kinetic energy associated with atmospheric winds Hydroelectric power The potential energy of tides Energy from the sun Chemical energy of fuels Nuclear energy
8.1 The steam power plant History Review
History # 8.1 The steam power plant Review #
Carnot-engine cycle for steam T P 2 2 3 3 S Py diagram for Carnot steam cycle TS diagram for Carnot steam cycle Carnot efficiency QW W Qc
Carnot-engine cycle for steam P V 4 3 P2 1 2 P1 PV diagram for Carnot steam cycle TS diagram for Carnot steam cycle 1 4 T S 3 2 T C T H TH TC Q H Q C W Carnot efficiency 1 C H H W T Q T η = =−
Simple team power plant (Fig.8.1) 1 2 Boiler W,(turbine） turbine Ws(pump) condenser 3 4 ↓o thermal efficiency 2 n= Ta 3
Simple team power plant (Fig. 8.1) 1 4 T S 3 2 T C T H Boiler condenser t u r bin e QH & (turbine) WS & QC & (pump) WS & 3 1 4 2 thermal efficiency 1 C H H W T Q T η = =−
8.1.1 Rankine Cycle The reason for introducing the Rankine Cycle (1)湿蒸汽对汽轮机有侵蚀作用； (2)绝热压缩过程难以实现： (3)蒸气比体积比液体大上千倍，设备及功耗大； (4)上限温度受制于临界温度，热效率不高
8.1.1 Rankine Cycle 8.1.1 Rankine Cycle The reason for introducing the Rankine Cycle ? The reason for introducing the Rankine Cycle ? （ 1）湿蒸汽对汽轮机有侵蚀作用； （ 2）绝热压缩过程难以实现； （ 3）蒸气比体积比液体大上千倍，设备及功耗大； （ 4）上限温度受制于临界温度，热效率不高
The Rankine Cycle T 2 Boiler W、(turbine) turbine Ws(pump) condenser 4 3 ↓Q The four steps(see P286) In boiler 定压升温→沸点 定温定压汽化→饱和蒸汽定压升温→过热蒸汽
The Rankine Cycle The Rankine Cycle Boiler condenser turbine QH & (turbine) WS & QC & (pump) WS & 3 1 4 2 T S 1 4 3 2 The four steps (see P286) The four steps (see P286) In boiler In boiler ⎯定压升温 ⎯ →⎯⎯ 沸点 ⎯定温定压汽化 ⎯ →⎯⎯⎯ 饱和蒸汽 ⎯定压升温 ⎯ →⎯⎯ 过热蒸汽
The differences between The Rankine Cycle and The Carnot Cycle 2 3 Two major respects (see P286)
The differences between The Rankine Cycle and The Carnot Cycle The differences between The Rankine Cycle and The Carnot Cycle T S 1 4 3 2 1 4 T S 3 2 T C T H Two major respects (see P286) Two major respects (see P286)
Simple practical power cycle (see P286) The Rankine Cycle
T S 1 4 3’ 3 2 Simple practical power cycle (see P286) Simple practical power cycle (see P286) T S 1 4 3 2 The Rankine Cycle The Rankine Cycle