1、3 Vapor refrigeration cycles3.1 One-stage vapor compression systems3.2 Two-stage vapor compression systems3.3 Cascade vapor compression systems3.4 Vapor absorption systems 第三章 蒸汽制冷循环第一节 单级蒸气压缩制冷循环第二节 两级蒸气压缩制冷循环第三节 复叠式制冷循环第四节 蒸气吸收制冷循环3.2 Two-stage vapor compression systems3.2.1 Introduction3.2.2 Desi
2、gn type analysis3.2.3 Operation type analysis第二节第二节 两级蒸气压缩制冷循环两级蒸气压缩制冷循环一、绪论二、设计型分析三、操作型分析2/28/202333.2 Two-stage vapor compression systems 第二节 两级蒸气压缩制冷循环 3.2.1 Introduction 一、绪论 Discharge capacity:f（PR）qvsqvt;Throttle loss:q0 Q0qmq0 qvtq0/v1;Discharge temperature t2.Reasons:（pKp0）and PR(-40)1点制冷剂体积
3、流量压缩机实际输气量qvsqmv1 qvt qmqvt/v1 输气系数、容积效率qvt理论输气量2/28/202343.2 Two-stage vapor compression systems 第二节 两级蒸气压缩制冷循环 3.2.1 Introduction 一、绪论 Cascade compression systems(70140)Multi-stage compression systems(4070)Method 1 1 2 4 TH TL T s 2 2”1 2 6 7 9 4 5 2/28/202353.2 Two-stage vapor compression systems
4、 第二节 两级蒸气压缩制冷循环 3.2.1 Introduction 一、绪论 Cascade compression systems(70140)Multi-stage compression systems(4070)Method 2 2/28/202363.2 Two-stage vapor compression systems 第二节 两级蒸气压缩制冷循环 3.2.2 Design type analysis 二、设计型分析Type of cyclesKind of refrigerantsTemperature differenceCompressor efficiencyPs C
5、ompressor motorQk CondenserQ0 Evaporatorqm Compressors,valves and pipesTH TL DesignResultsUser specified:TH、TL、Q0Designer chosen:TH、TL、el、f3.2 Two-stage vapor compression systems3.2.1 Introduction3.2.2 Design type analysis3.2.2.1 Single-throttle cycles 3.2.2.2 Double-throttle cycles 3.2.3 Operation
6、type analysis第二节第二节 两级蒸气压缩制冷循环两级蒸气压缩制冷循环一、绪论二、设计型分析（一）一次节流循环（二）二次节流循环三、操作型分析2/28/202383.2.2.1 Single-throttle cycles（一）一次节流循环 3.2.2.1.1 No interstage cooling 无中间冷却ph12(6)745 1 2 6 7 9 4 5 No interstage cooling Throttle loss:q0 const Q0qmq0 Discharge capacity:f（PR）qvsqvt Discharge temperature t22/28/
7、202393.2.2.1 Single-throttle cycles（一）一次节流循环 3.2.2.1.2 With incomplete interstage cooling 中间不完全冷却 1 2 6 7 9 4 5 10 3 qmgqmd qmd qmg 1 2 6 7 9 4 5 No interstage coolingWith incomplete interstage cooling2/28/2023103.2.2.1 Single-throttle cycles（一）一次节流循环 3.2.2.1.2 With incomplete interstage cooling 中间不
8、完全冷却 1 2 6 7 9 4 5 10 3 qmgqmd qmd qmg With incomplete interstage cooling2/28/2023113.2.2.1 Single-throttle cycles（一）一次节流循环 3.2.2.1.3 With complete interstage cooling 中间完全冷却 2 1 6 7 9 4 5 10 3 qmd qmd qmg 1 2 6 7 9 4 5 10 3 qmgqmd qmd qmg 10982/28/2023123.2.2 Design type analysis 二、设计型分析3.2.2.1 Sing
9、le-throttle cycles（一）一次节流循环User specified:TH、TL、Q0Designer chosen:TH、TL、Tm iH、iL、mH、mLDesign parametersMode of intercoolingNo interstage coolingWith incomplete interstage coolingWith complete interstage cooling1Tk、T0、tm、t4pk、p0、pmTkTHTkpk ;tm pmT0TL-T0p0 ;t4tmtm（tm5）2t2、t7 h2h1（h2sh1）/id;h7h6（h7sh6）
10、/igt6t6t2h6h3（h7h6）qmL/qmHt6t310982/28/2023133.2.2.1 Single-throttle cycles（一）一次节流循环 3.2.2.1.2 With incomplete interstage cooling 中间不完全冷却 1 2 6 7 9 4 5 10 3 qmgqmd qmd qmg 1098qmHh6qmLh2（qmHqmL）h3 h6h3（h2h3）qmL/qmH 2/28/2023143.2.2.1 Single-throttle cycles（一）一次节流循环 3.2.2.1.2 With incomplete intersta
11、ge cooling 中间不完全冷却 1 2 6 7 9 4 5 10 3 qmgqmd qmd qmg 1098qmHh9qmLh4（qmHqmL）h3 qmHqmL（h3h4）/（h3h9）2/28/2023153.2.2.1 Single-throttle cycles（一）一次节流循环 3.2.2.1.3 With complete interstage cooling 中间完全冷却 2 1 6 7 9 4 5 10 3 qmd qmd qmg qmHh9qmLh2qmLh4qmHh3 qmHqmL（h2h4）/（h3h9）2/28/2023163.2.2 Design type an
12、alysis 二、设计型分析3.2.2.1 Single-throttle cycles（一）一次节流循环Mode of intercoolingNo interstage coolingWith incomplete interstage coolingWith complete interstage cooling3q0、qkwL、wHq0h1h4 、wLh2h1qkh7h9 、wHh7h64qmLqmLQ0/q0Q0/（h1h4）（3-43）qmH/qmdL1(h3h4)/(h3h9)(h2h4)/(h3h9)5qmHqmHqmL qmHqmL (3-47)qmHqmL (3-47)Us
13、er specified:TH、TL、Q0Designer chosen:iH、iL、mH、mL Design parameters10982/28/2023173.2.2 Design type analysis 二、设计型分析3.2.2.1 Single-throttle cycles（一）一次节流循环User specified:TH、TL、Q0Designer chosen:iH、iL、mH、mL Design parametersMode of intercoolingNo interstage coolingWith incomplete interstage coolingWit
14、h complete interstage cooling6PtL PtLqmLwLqmL（h2h1）（3-44）PtH PtHqmHwHqmgH(h7h6)（3-48）PtPtPtLPtHqmH/qmdL1(h3h4)/(h3h9)(h2h4)/(h3h9)7Q0/Pt(h1h4)/(h2h1)+(h7h6)（3-49）8QkQkqmHqkqmH（h7h9）9QmQmqmL（h9h4）10982/28/2023183.2.2 Design type analysis 二、设计型分析 3.2.2.4 Determination of interstage temperature（三）中间温度的
15、确定1.(MPa)2.(K)3.tm=0.4tk+0.6to+3 ()kompppkomTTTf(Tk、T0、Tm)Tmopt f(max)2/28/202319 opt -10 -8 -6 -4 -2 0 tm/tmopt 0 3.2.2 Design type analysis 二、设计型分析 3.2.2.4 Determination of interstage temperature（三）中间温度的确定f(Tk、T0、Tm)Tmopt f(max)opt f(Tk、T0、Tmopt)（3-64）HLmLmHLmLHmHvtLvtHvvqqvqvqqq1313qvsqmv1 qvt2/28/202320Homework_1212.12.画出一次节流、中间完全冷却的两级氨压缩制冷系统流程画出一次节流、中间完全冷却的两级氨压缩制冷系统流程图和理论循环的图和理论循环的lgp-hlgp-h图。冷凝温度为图。冷凝温度为4040，中间冷却器的传，中间冷却器的传热温差热温差t=5t=5，低温蒸发器的蒸发温度为，低温蒸发器的蒸发温度为-40-40，求高、低，求高、低压级压缩机气缸的容积比？压级压缩机气缸的容积比？(高、低压级压缩机的输气系数分高、低压级压缩机的输气系数分别为别为0.70.7和和0.8)0.8)。
