1

Unit Seven

Refrigeration and Refrigerants

2Refrigeration and heat pump

High temperature

Low temperature

RefrigerationEnergy

TH

TL

QH

QL

High temperature

Low temperature

Heat pumpEnergy

TH

TL

QH

QL

Summer

indoor

outdoor

Winter

outdoor

indoor

3vapor compression system

4

5

6

Indoorheat exchanger

Compressor

Expansion valve

四通换向阀

Four-way Reversing Valve

Outdoorheat exchanger

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Entropy

Absolutetemperature

1

2

3

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Theoretical Vapor Compression Refrigeration Cycle 1-2 The cold saturated vapor at state 1 is compressed isentropically to the high temperature in the cycle at state 2. 2-3 The cycle is completed by an isothermal and isobaric heat rejection or condensing process from state 2 to state 3. 3-4 Saturated liquid at state 3 expands isenthalpicaly to the low temperature

and pressure of the cycle at state 4. 4-1 Heat is added isothermally and isobarically by evaporating the liquid phase refrigerant from state 4 to state 1.

Enthalpy

Pressure

1

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4

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COP: Coefficient of Performance

EER: Energy Efficiency Ratio

HSPF: Heating Seasonal Performance Factor

SEER: Seasonal Energy Efficiency Ratio

Btu of heat produced

Btu worth of electricity usedCOP

Btu/hr of cooling

watts usedEER

Btu of heat produced over the heating season

watt-hours of electricity used over the heating seasonHSPF

seasonal Btu of cooling

seasonal watt-hours usedSEER

9absorption system

water lithium bromideammonia water

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11

Ozone Depletion !

反应输入物反应产物 反应催化剂

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decreaseincrease temperature

increase

atmosphere

earth

Global Warming !

Greenhousegases

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14

Arctic sea ice

15Reciprocation Compressor

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Rotary Compressor

17Screw Compressor

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Scroll Compressor

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Centrifugal Compressor

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1. Refrigeration and Refrigeration Systems

definition & classification of Refrigeration Systems

2. Refrigerants, Cooling Mediums, and Absorbents

definition & standard refrigerant designations

3. Classification of Refrigerants

classification of refrigerants based on ozone depletion

4. Phaseout of CFCs, BFCs, HCFCs, and Their Blends

history of the phaseout some alternatives

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Frequently used words and phrases:refrigeration 制冷 refrigeration system 制冷系统refrigerant 制冷剂 cooling medium 冷却介质vapor compression system 蒸气压缩式系统absorption system 吸收式系统gas expansion system 气体膨胀式系统ozone depletion potential (ODP) 臭氧消耗潜能global warming potential (GWP) 全球变暖潜能absorbent 吸收剂 brine 盐水hydrocarbon 碳氢化合物 halocarbon 卤代烃phaseout 逐步停用或淘汰 alternative 替代物Hydrofluorocarbons (HFCs) 氢氟烃Hydrochlorofluorocarbons (HCFCs) 氢氯氟烃Chlorofluorocarbons(CFCs) 氯氟烃Bromofluorocarbons(BFCs) Halons 溴氟烃HC （ Hydrocarbon ） 碳氢 FC （ Fluorocarbon ）

氟烃azeotropic 共沸的nonazeotropic 非共沸的

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1. Refrigeration is the cooling effect of the process of extracting heat from a lower temperature heat source, a substance or cooling medium, and transferring it to a higher temperature heat sink, probably atmospheric air and surface water, to maintain the temperature of the heat source below that of the surroundings.

2. A refrigeration system is a combination of components, equipment, and piping, connected in a sequential order to produce the refrigeration effect.

cooling effect: 冷却作用 heat source: 热源 heat sink: 热汇cooling medium: 冷却介质 surrounding: ( 周围 ) 环境

in a sequential order: 顺序的 refrigeration effect: 制冷效应

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3. The compressed refrigerant is condensed into liquid form by releasing the latent heat of condensation to the condenser water.

4. Liquid refrigerant is then throttled to a low-temperature vapor, producing the refrigeration effect during evaporation.

5. After liquid refrigerant produces refrigeration during evaporation at very low pressure, the vapor is absorbed by an aqueous absorbent.

latent heat: 潜热 sensible heat: 显热condenser water: 冷却水

aqueous: 水的 水成的 absorbent: 吸收剂 吸收的

throttle: 节流 节流阀 expansion valve: 膨胀阀capillary: 毛细管

24capillary expansion valve

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6. The solution is heated by a direct-fired gas furnace or waste heat, and the refrigerant is again vaporized and then condensed into liquid form.

7. A refrigerant is a primary working fluid used to produce refrigeration in a refrigeration system.

8. All refrigerants extract heat at low temperature and low pressure during evaporation and reject heat at high temperature and pressure during condensation.

solution: 溶液 解答 direct-fired gas furnace : 直燃式燃气炉waste heat: 废热

primary working fluid: 初级工作流体

extract: 吸取 吸收 抽出 reject: 排放 拒绝

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9. In a large, centralized air-conditioning system, it is more economical to pump the cooling medium to the remote locations where cooling is required.

10. Chilled water and brine are cooling media.

11. They are often called secondary refrigerants to distinguish them from the primary refrigerants.

centralized air-conditioning system: 集中式空调系统 economical: 节约的 经济的 economic: 经济的 经济学的 有关经济的

chilled water: 冷冻水 brine: 盐水

secondary refrigerants: 二级制冷剂 primary refrigerant: 初级制冷剂

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12. The refrigerant vaporizes, and the solution is restored to its original concentration to absorb water vapor again.

13. According to ANSI/ASHRAE Standard, the first digit is the number of unsaturated carbon-carbon bonds in the compound.

14. To compare the relative ozone depletion of various refrigerants, an index called the ozone depletion potential (ODP) has been introduced.

restore: 恢复 concentration: 浓度

ANSI: American National Standards Institute compound: 化合物digit: 数字 unsaturated carbon-carbon bonds: 未饱和 C-C 键

ozone depletion: 对臭氧层的消耗破坏ozone depletion potential (ODP) : 臭氧消耗潜能introduce: 引入

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15. ODP is defined as the ratio of the rate of ozone depletion of 1 lb of any halocarbon to that of 1 lb of refrigerant R-11.

16. Similar to the ODP, halocarbon global warming potential (HGWP) is an index used to compare the global warming effect of a halocarbon refrigerant with the effect of refrigerant R-11.

17. Nontoxic and nonflammable synthetic chemical compounds called halogenated hydrocarbons,

the rate(ratio) of…to…: … 与…的比值 lb: pound 磅halocarbon: 卤代烃

nontoxic: 无毒的 toxic: 有毒的synthetic: 人造的 合成的 halogenate: 卤化

similar to: 类似于… global warming potential (GWP) : 全球变暖潜能global warming effect: 全球变暖效应

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18. An azeotropic is a mixture of multiple components of volatilities (refrigerants) that evaporate and condense as a single substance and do not change in volumetric composition or saturation temperature when they evaporate or condense at constant pressure.

19. ASHRAE assigned numbers between 500 and 599 for azeotropic.

20. Zeotropic or nonazeotropic, including near azeotropic, shows a change in composition due to the difference between liquid and vapor phases, leaks, and the difference between charge and circulation.

azeotropic: 共沸的 ( 制冷剂 ) volatility: 挥发性物质volumetric composition: 体积构成 saturation temperature: 饱和温度

zeotropic nonazeotropic: 非共沸的 ( 制冷剂 )leak: 泄漏 charge: 充注 circulation: 循环

assign for: 分配指派

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21.The difference in dew point and bubble point during evaporation and condensation is called glide, expressed in ℉.

22. Near azeotropic has a smaller glide than zeotropic.

23. HCFCs have a much shorter lifetime in the atmosphere (in decades) than CFCs and cause far less ozone depletion (ODP 0.02 to 0.1).

dew point: 露点（温度） bubble point : 泡点（温度）glide ：滑移（温度） ℉ : 华式温度 Fahrenheit CelsiusCelsius thermometer Fahrenheit thermometer

lifetime: 寿命 decade: 十年

glide: 温度 (滑移 )

Tc = （ 5 / 9 ） × （ Tf - 32 ）

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2 dew point

4 bubble point

2-4 glidetA

tBgas

liquid

wBG4

A

1

2

3

4

5

wBL2

BwBL3wBG3

露点温度

泡点温度

温度滑移

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23. They are transitional or interim refrigerants and are scheduled for a restriction in production starting in 2004.

24. the European Economic Community and 24 nations, including the United States, signed a document called the Montreal Protocol.

25. concern two important issues: the phaseout of CFCs and the prohibition of deliberate venting of CFCs and HCFCs.

transitional ：过渡的 变迁的 interim: 过渡的 中间的 临时的schedule: 安排 ( 时间 ) 时间表

phaseout: （分阶段）逐步结束，逐步停止deliberate: 蓄意的 故意的 vent: 排放

European Economic Community (EEC): 欧洲经济共同体European Union (EU): 欧盟Montreal Protocol: 蒙特利尔议定书 1987 9Kyoto Protocol: 京都议定书 1997 12 2001 3

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26. In February 1992, President Bush called for an accelerated ban of CFCs in the United States.

27. In late November 1992, representatives of 93 nations meeting in Copenhagen agreed to phase out CFCs beginning January 1, 1996.

28. In the earlier 1990s, R-11 was widely used for centrifugal chillers, R-12 for small and medium-size vapor compression systems, R-22 for all vapor compression systems, and CFC/HCFC blend R-502 for low-temperature vapor compression systems.

accelerated: 加速的 ban: 禁止 取缔

centrifugal chillers: 离心式冷水机

representative: 代表 典型的 有代表性的phase out: 使逐步淘汰 , 逐渐停止

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29. R-134a is not miscible with mineral oil; therefore, a synthetic lubricant of polyolester is used.

30. R-407C has a drop of only 1 to 2% in capacity compared with R-22.

31. R-507 (R-125/R-143a), an HFC’s azeotropic with ODP = 0, is a long-term alternative to R-502.

miscible: 易混合的 mineral oil: 矿物油lubricant: 润滑剂 polyolester: 聚油酸酯 多元醇酯 POE 酯类油

alternative: 可供选择的事物 , 选择性的 二中选一的

drop: 下降 capacity: ( 机组制冷 ) 能力或容量

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Usages and Expressions 有关“数字”的表达

数字表达的标准

大陆制（美、法、欧洲等国采用）

每增大一千设置一新单位，称为 thousand system

英国制（英、德采用）

每增大一百万设置一新单位，称为 million system

中国制（我国习惯）

万以上的数字，每增大一万设置一新单位，如万、亿、兆，但在“兆”以后，则采用“亿”或“兆”的重复表示。

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Usages and Expressions 有关“数字”的表达

数字表达的标准

单词 大陆制 英国制 中国制译法（大陆制为准）

ten 101 101 十

hundred 102 102 百

thousand 103 103 千

million 106 106 百万

billion 109 1012 十亿

trillion 1012 1018 兆

quadrillion 1015 1024 千兆

在科技英语的翻译中，遇到超过 billion 以上的词，可以通过该科技文献的来源、出版地和作者，根据文章的上下文关系、内容的逻辑常识、科学的规律定则来判断数字的大小。

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Usages and Expressions 有关“数字”的表达

数字的表示法

1 用阿拉伯数字

1.1 在句首

在句首一般使用英语单词

Two men pushed on the crank with equal forces.

数字后面没有名词时，常用阿拉伯数字

300 decreased by 100 is 200.

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Usages and Expressions 有关“数字”的表达

数字的表示法1 用阿拉伯数字 1.2 在句中 个位数常用英语单词，十位数以上常用阿拉伯数字； Matter exists in three states: solid, liquid and gas.

The corporation produces a range of 16 alloy steel grades.

一句话中出现一个以上的个位数字（包括一些十位数）时，都用阿拉伯数字表示，或都用英文单词表示； He used a crew of 3 carpenters, 1 plumber, 6 laborers, 1 foreman, and 1 timekeeper.

单位名词前的数字通常用阿拉伯数字表示。 The car gained each second a speed of 4 feet per second.

At a speed of 17,500 miles per hour, …

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Usages and Expressions 有关“数字”的表达

数字的表示法1 用阿拉伯数字 1.3 两数连用 分别用英文单词及阿拉伯数字写出，习惯上将词组或句子之首计数的数字用英文单词写出； three 15 W lamps two 4-ton trucks