土木工程专业英语unit-8(3)课件.ppt

1、 drive/promotepropel/motivaten.排气v.排出、排气(remove/discharge）耗尽/枯竭deplete/drain/dry up/use up/run out ofreplace/substitute forbadadversedisadvantageoushygeiansanitaryelementaryinitialoriginalinitiatoryallowableNatural air change takes place in buildings as a result of wind and the difference in density

2、 between the indoor and outdoor air.建筑物里产生自然换气建筑物里产生自然换气,是由于风和室内外空气是由于风和室内外空气密度差作用的结果。密度差作用的结果。A very large consumption of energy would be required to move such quantities by mechanical means.The great economic importance of natural ventilation is that it can bring about these air changes without ex

3、penditure of mechanical energy.利用机械方式使这么多的空气流动需要消耗大量的能源。自然通风的最大的经济上的重要意义，就在于它不必消耗机械能即可产生大量换气。consume:V.消耗 exhaustdeplete/expendproducegenerateconsumption/depletionThe time has long passed when it was necessary to demonstrate the benefits of natural ventilation and justify its application.The proofs

4、were simple and very convincing.They were based on comparisons of mechanical ventilation and natural ventilation.需要解释自然通风的益处和证实其需要解释自然通风的益处和证实其应用的合理性的时代早已过去。证应用的合理性的时代早已过去。证据很简单而且富有说服力，是通过据很简单而且富有说服力，是通过机械通风和自然通风对比后得出的。机械通风和自然通风对比后得出的。Jokes(英语笑话）Who do you think you are?The bus was crowded,and as on

5、e more man tried to get on,the passengers wouldnt let him aboard.It is too crowded,they shouted.who do you think you are?I am the driver.he said.If I am a Manager One day in class,the teacher assigned his students to write a composition If I Am a Manager.All the students began to write except a boy.

6、The teacher went to him and asked the reason.I am waiting for my secretary,was the boys answer.早晨特冷，和朋友一块去ATM取钱，巧遇运钞车加钞，只得站一旁等候。朋友问我冻手不？我冷冷的说“冻手！”瞬间四杆枪指向我俩.被送入派出所。路上一直沉默。我问朋友你怎么不开腔呢？瞬间八杆枪指向我俩。警察：你叫什么名字？我：蒋英羽警察：什么名字？我：蒋英羽警察：Whats your nameIn hot shops where all the emphasis was laid on mechanical ven

7、tilation,and natural ventilation,being regarded as unimportant,was not taken into account at all,it was found in all the tests that the volume of natural air change many times exceeded the volume of mechanical ventilation.在高温车间里，主要着重于机械通风，而把自然通风视为不重要根本不予考虑。在所有的测试中显示，自然换气的体积比机械通风的体积超出很多倍。lay emphasis

8、 onpay attention toattach importance tothink highly ofbe known asbe identified asThis revealed the negligible role of general mechanical ventilation despite its heavy installation and running costs.这表明，尽管全面机械通风的装置大，而且运行费用高，但其作用却是微不足道的。despite/in spite of 都是介词，后面不能跟句子。(though/although)Ex:尽管他很忙，他还是来了车

9、站迎接我们.Despite he being busy,he came to the station to meet us.Despite the fact that he was busy,he came to thestation to meet us.In spite of being busy,he came to the station to meet us.Mechanical ventilation in these cases was best used as a corrective to natural ventilation,in the form of air curt

10、ains and local air supply or extraction.在这些情况下，机械通风最好是以空气幕和局部送排风的形式作为对自然通风的一种补充。n.补充complement/supplementThe effectiveness of natural ventilation depends on many factors which must be considered in using the building as well as in planning it.自然通风的有效程度取决于很多因素。这些因素不仅在规划建筑物时而且在使用建筑物时都必须加以考虑。rely onlie

11、 onhinge onThe most satisfactory solutions are obtained when the architect and the engineer collaborate and take account of problems of natural ventilation as well as those numerous and complex requirements that industrial undertakings have to satisfy at the design stage.若建筑师和工程师共同合作，并在设计阶段既考虑满足工业企业

12、的繁杂要求，又考虑自然通风问题，才能获得令人满意的解决方法。To clarify the problems of natural ventilation we shall first of all discuss the effects of heat sources in a building in relation to the air currents they cause in single-bay and multi-bay buildings.为了阐明自然通风的问题，我们首先讨论在单跨和多跨建筑物里热源对由它产生的气流的影响.concerningaboutrelating tore

13、garding towith respect toIn view of the great complexity of a theoretical study of these phenomena,they are best investigated experimentally with the aid of two-and three-dimensional models using air or water as the working medium.鉴于这些现象理论研究的极端复杂性，最好是借助二维和三维模型，利用空气或水作介质进行试验研究。givenin view ofin consi

14、deration oftake sth into accounttake account ofExercises（练习）（练习）nI.Read the whole passage and answer the following questions.n1.What are the types of buildings which the air-conditioning system serves?n2.How can the air-conditioning systems be classified based on their size,construction,and operatin

15、g characteristics?n3.What are the components of packaged air-conditioning systems?n4.How many parts does the central air-conditioning systems consist of?n5.What is the air system and what is the function of it?n6.What are the components of control systems?n7.What medium can serve as the working subs

16、tance to condition air in air-conditioning cycle?n8.How can the air-conditioning cycles be classified according to the cycle performance?n9.How can the operating modes of air-conditioning cycles be classified according to the outdoor weather and indoor operating conditions?n10.Which factors should b

17、e considered when select the capacity of an equipment?nTranslate the following terms into English.n冷水机组 压缩循环冷却器n直膨式蒸发器 满液式蒸发器n风管 制冷循环n过热气体 过冷夜体n高温制冷 中央空调系统nFill in the blanks with the information given in the text.n1.Air-conditioning is a process that simultaneously conditions air;distributes it com

18、bined with the outdoor air to the conditioned space;and at the same time controls and maintains the required spaces _,_,_,_,sound level,and _within predetermined limits for the health and comfort of the occupants,for product processing,or both.n2.The acronym HVAC&R stands for_,_,_,and_.The combinati

19、on of these processes is equivalent to the functions performed by air-conditioning.n3.Based on their size,construction,and operating characteristics,air-conditioning systems can be classified as the following:_;_;_;_.n4.In institutional,commercial,and residential buildings,air-conditioning systems a

20、re mainly for the occupants health and comfort.They are often called_.In manufacturing buildings,air-conditioning systems are provided for product processing,or for the health and comfort of workers as well as processing,and are called_.n5.Both central and space-conditioning systems consist of the f

21、ollowing:_;_;_;_.n6.An air-conditioning process describes the change in thermodynamic properties of moist air between the initial and final stages of conditioning as well as the corresponding _between the _and_,such as water,refrigerant,absorbent,adsorbent,or moist air itself.What is ventilating？The importance of natural ventilating Next class we will talk about-Translation Skills Thank You!