《制冷与低温原理》课件C第三章 蒸气制冷循环 1 (3.1.1)04

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8/1/202223 Vapor refrigeration cycles第三章 蒸汽制冷循环Vapor refrigeration cyc

2、lesRefrigeration cycles( Phase change )Gas refrigeration cyclesVapor compression cyclesVapor absorption cycles8/1/202233 Vapor refrigeration cycles第三章 蒸汽制冷循环Refrigeration cycles using pure refrigerantRefrigeration cycles( Component )Refrigeration cycles using mixed refrigerant3.1 One-stage vapor com

3、pression systems3.1.1 Ideal cycles using pure refrigerants3.1.2 Practical cycles using pure refrigerants3.1.3 Practical cycles using mixed refrigerants 3.1.4 Analysis of cycles 第一节单级蒸气压缩制冷循环一、纯工质理论循环二、纯工质实际循环三、混合工质循环四、循环特性分析3.1 One-stage vapor compression systems3.1.1 Ideal cycles using pure refrige

4、rants3.1.1.1 Saturated cycles3.1.1.2 Subcooled cycles3.1.1.3 Superheated cycles3.1.1.4 Recuperative cycles第一节单级蒸气压缩制冷循环一、纯工质理论循环（一）饱和循环（二）过冷循环（三）过热循环（四）回热循环8/1/20226Joule-Thomson effect and J. Perkins ( 1844, American )EvaporatorEtherCondenserCompressorExpansion valves8/1/202273.1 One-stage vapor co

5、mpression systems 第一节 单级蒸气压缩制冷循环3.1.1 Systems using pure refrigerants 一、纯工质理论循环THTL4123TsOverheated corner8/1/202283.1 One-stage vapor compression systems 第一节 单级蒸气压缩制冷循环3.1.1 Systems using pure refrigerants 一、纯工质理论循环Overheated corner8/1/202293.1.1 Systems using pure refrigerants 一、纯工质理论循环3.1.1.1 Sat

6、urated cycles （一）饱和循环Assumptions1. An isentropic compression2. No temperature diffidence3. Saturated liquid and vapor 4. No pressure loss8/1/2022103.1.1 Systems using pure refrigerants 一、纯工质理论循环3.1.1.1 Saturated cycles （一）饱和循环Energy balancesPartsCompressorCondenserExpansionEvaporatorFeaturesq0w0q0,w

7、0w0Relationsw0h2-h1qkh2-h4h4h5q0h1-h5 qkh = q + w8/1/2022113.1.1 Systems using pure refrigerants 一、纯工质理论循环3.1.1.1 Saturated cycles （一）饱和循环IndexExpressionInfluence to cycle1q0q0h1-h5Gains2w0w0h2-h1Energy cost300q0/w0Energy cost4000/cEnergy cost5qkqkh2-h4Material cost6qvqvq0/v1Material cost7pkpkps(Tk)

8、Material cost8p0p0ps(T0)Material cost9t2t2f(PR,k)Material cost10PRPRpk/p0Material costqkqk8/1/2022123.1.1 Systems using pure refrigerants 一、纯工质理论循环3.1.1.1 Saturated cycles （一）饱和循环IndexR134aR22R717Influence1q0128.5147.01043.1Gains2w042.646.59319.9Energy cost303.0163.1553.2610q0/w04qv872.91595.91673.9

9、Material cost5r0213219.51329qvq0/v16pk1016.41533.61555.5Material cost7p0132.7244.9190.18tc101.196133p0、pk9tf-96.6-160-77.910tb-26.1-40.76-33.311t248.467.6135.2Material cost12PR7.666.268.18t2t1(PR)(k-1)/k13k1.11.21.314Mol102.0386.4817.03k8/1/2022133.1.1 Ideal cycles using pure refrigerants 一、纯工质理论循环3

10、.1.1.2 Subcooled cycles （二）过冷循环Assumptions 1. An isentropic compression2. No temperature diffidence 3. Subcooled liquid 4. No pressure loss8/1/2022143.1.1 Ideal cycles using pure refrigerants 一、纯工质理论循环3.1.1.2 Subcooled cycles （二）过冷循环IndexExpressionInfluence to cycle1q0q0 = h1 h4 = h1 h4 q0 02w0w0 w

11、0w0 = 0300q0 /w0 0 Beneficial4000 /c 0 5qvqvq0 /v1 qv Beneficial8/1/2022153.1.1 Ideal cycles using pure refrigerants 一、纯工质理论循环3.1.1.3 Superheated cycles （三）过热循环Assumptions 1. An isentropic compression2. No temperature diffidence 3. Superheated vapor 4. No pressure loss8/1/2022163.1.1 Ideal cycles us

12、ing pure refrigerants 一、纯工质理论循环3.1.1.3 Superheated cycles （三）过热循环IndexExpressionsInfluence to cycle1q0q0q0q 0=02w0w0 w 0w 0 0300q0 /w00 Harmful4000 /c0 5q vq vq0 /v1qv 8/1/2022173.1.1 Ideal cycles using pure refrigerants 一、纯工质理论循环3.1.1.4 Recuperative cycles （四）回热循环Assumptions 1. An isentropic compre

13、ssion2. No temperature diffidence 3. Add a recuperative process 4. No pressure loss8/1/2022183.1.1 Ideal cycles using pure refrigerants 一、纯工质理论循环3.1.1.4 Recuperative cycles （四）回热循环IndexExpressionsInfluence to cycle1q 0q0 = h1 h4 = q0 q0 02w0w0 w 0w 0 0400q0 /w0 0 ？Beneficial：R502、R290、R600a、R134aHarmful：R22、R7