1、TextAccording to the ventilation system of the power：According to the ventilation system of power,ventilation mode can be divided into natural ventilation and mechanical ventilation.1.Natural ventilationNatural ventilation is to rely on indoor and outdoor air temperature difference caused by the hot
2、 pressing and outdoor wind pressure caused by the way to realize the air ventilation.1）Under the action of thermal natural ventilationA diagram in figure 1 for using thermal natural ventilation,due to the high air temperature in the rooms,density is small,so produced a kind of upward force,to make t
3、he room air rises and discharge from the upper window,outdoor cold air into the indoor from the room below the Windows of the holes or cracks.Under the action of this ventilation mode is called thermal natural ventilation.Figure 1 Natural ventilation under the hot actionText2）the natural ventilation
4、 under the action of wind pressureFigure 2 is a natural ventilation diagram by the action of wind pressure,Air flow enter the room from the windows and doors which on the buildings windward.At the same time Squeeze out the indoor air from the windows and doors which on the buildings lee side.Therefo
5、re,a kind of natural ventilation is formed in the room caused by wind.This way of ventilation is called the natural ventilation under the action of air pressure.Natural ventilation can be divided into Organized natural ventilation and unorganized natural ventilation.The Organized natural ventilation
6、 is conducted by the workshops Side window and skylights,By controlling its opening degree,Adjust the air inflow and displacement;The unorganized natural ventilation is conducted by the doors and windows aperture.Figure 2 Natural ventilation under wind pressureTextThere are many factors which can af
7、fect the natural ventilation,Such as indoor and outdoor air temperature,outdoor air flow velocity and flow direction,shop Windows and doors holes size and location.So the Air volume is constantly changing.So we need to constantly adjust the air outlet opening degree according to the specific situati
8、on to met the demand.Natural ventilation is characterized by small investment,good economy,but the effect and applicable scope is small,It is mainly used for Industrial workshop;Because of the uncertainty of the natural wind,So,Under normal circumstances,we regard the natural ventilation by wind eff
9、ect s when doing the design.2.Mechanical ventilation Mechanical ventilation is the use of power generated by theventilators,ventilating mode.Figure 3 is the use of the exhaust pipe exhaust uniformly.Figure 4 is will drain away harmful gases from several local locations.Figure 3 uniform exhaust syste
10、mFigure 4 local exhaust systemTextFigure 5 is the dust removal system,the dust removal system can also be used to recycle powder.Figure 6 system for mechanical ventilation,outdoor air under the action of fan by blinds into the intake chambers.After hitches in inlet chambers filter,heater heating,thr
11、ough the duct into the ventilation room.Figure 5the dust removal system 1Pests collector；2air duct；3fan；4dust collectorFigure 6mechanical ventilation system1the shutters；2air filter；3air heater；4the ventilator；5duct；6air treatment room；7motor；8air distributorTextAccording to the role of the ventilat
12、ion system:According to the scope of the ventilation system,ventilation system can be divided into comprehensive ventilation and local ventilation.1.The comprehensive ventilationComprehensive ventilation is in the room thoroughly ventilated take a breath.The comprehensive ventilations purpose is to
13、dilute the pollutants in the air and provide the heat of the room needs.Characterized by a wide range,large air volume,high investment and operating cost,when using local ventilation mode is difficult to ensure hygiene standards adopted.Comprehensive ventilation can make use of mechanical ventilatio
14、n,also can be use to natural ventilation to achieve,the comprehensive ventilation can be divided into comprehensive exhaust and overall supply.2.Local ventilation Local ventilation can be divided into local exhaust and local supply.TextLocal exhaust is after discharge to capture,purify the pests on
15、the outside,And local air supply are processed,conform to the requirements of the air to the local working place,to ensure the air condition of local area.The characteristics of local ventilation is the pest control effect is good,small volume,small investment,low operating cost.According to the cha
16、racteristics of the ventilation system:According to the characteristics of the ventilation system,ventilation system can be divided into air supply and exhaust air.1.The supply airThe fresh air into the indoor is called supply air.2.Exhaust airThe foul air inside the room after processing to meet di
17、scharge standards emissions called exhaust.In actual engineering,from the perspective of technical economy,the priority should be given to the natural ventilation,when it cannot satisfy the need to adopt mechanical ventilation;Give priority to with local ventilation,adopts the comprehensive ventilat
18、ion when it cannot satisfy the need.In practical engineering,using a way of ventilation is often can not satisfy the need of the effect,is usually a variety of ventilation method is used in combination.Louvern.百叶窗Piecen.(通风)部件control valve调节阀 control velocity控制风速 controlled natural ventilation有组织自然通
19、风 controlled plant调节对象cross-ventilation 穿堂风exhaust air rate排风量 exhaust fan排风机 local air suppiy system局部送风系统 local exhaustventilation(LEV)局部排风New Words and PhrasesNotes（1）Natural ventilation is to rely on indoor and outdoor air temperature difference caused by the hot pressing and outdoor wind pressu
20、re caused by the way to realize the air ventilation.自然通风是依靠室内和室外空气温差引起的热压及室外风压造成的方式实现空气通风。（2）There are many factors which can affect the natural ventilation,Such as indoor and outdoor air temperature,outdoor air flow velocity and flow direction,shop Windows and doors holes size and location.有许多影响自然通
21、风的因素，例如，室内和室外空气温度、室外空气流速和流向、门和窗孔的大小及位置等。（3）According to the scope of the ventilation system,ventilation system can be divided into comprehensive ventilation and local ventilation.根据通风系统的作用范围，通风系统可以分为全面通风和局部通风。（4）The characteristics of local ventilation is the pest control effect is good,small volume
22、,small investment,low operating cost.局部通风的特点是害虫控制效果好，风量小，投资小，运行成本低。1.In relating the static velocity,potential,and total heads plus the losses flow,the energy equation permits writing of an expression encompassing all flow variables between any two points in the ventilation system.2.In order to inst
23、all the base of heat air-conditioning and air duct,all the materialsneeds to be inspected.3.Ventilating(the V in HVAC)is the process of changing or replacing air in anyspace to provide high indoor air quality.4.通风空调工程中的部件包括各种风口.风阀.罩类.风帽及柔性短管等部件。5.通风空调主要设备有空调机组.通风机.排风机组等，设备的安装根据设计图纸，按照安装顺序进行，并应符合质量要求。Exercises（Translate the following Chinese into English,or English into Chinese）
