压缩机及汽轮机简介课件

1、壓縮機基本簡介,動能式壓縮機 Dynamic compressor,Maximum Pressures and Capacities of Air Compressors,壓縮機最大壓力及容積,壓縮機應用範圍,Centrifugal Compressors,Centrifugal Compressors,Centrifugal Compressors,離心式壓縮機,Sketch of a centrifugal compressor with a vaned diffuser.,The elements of a centrifugal compressor,Centrifugal Compr

2、essor,Fluid Mechanics of Centrifugal Compressor (radial compressor),Flow enters the compressor parallel to the impeller axis and is accelerated by the blades, greatly increasing its velocity, and thus its total pressure. The gas leaves the impeller and is decelerated as smoothly as possible to conve

3、rt the kinetic energy imparted in the impeller to static pressure.,Fluid Mechanics of Centrifugal Compressor (Radial Compressor),The deceleration of the gas is carried out in the diffuser. While some compressors use a vaned diffuser to decelerate the gas, most use a diffuser without vanes where the

4、shape of the housing is carefully designed to minimize pressure losses.,Fluid Mechanics of Centrifugal Compressor (Radial Compressor),As the air flow leaves the compressor wheel, it has a relative velocity parallel to the blade, but the absolute velocity is found by adding the blade tip velocity to

5、this relative exit velocity. The scroll, as shown in the figure increases in both depth and width.,Fluid Mechanics of Centrifugal Compressor (Radial Compressor),This provides greater area for the flow and also moves the flow to larger radius. Both these design features slow down the flow and convert

6、 its kinetic energy into pressure due to the conservation of momentum of the flow. A well designed radial compressor has an efficiency of 65%-75%.,離心式壓縮機剖面,Centrifugal Compressor Impellers,There are three (3) types of impellers normally used in the centrifugal compressor. These are:,開放式,半開放式,封閉式,OPE

7、N Built with the blades in a radial direction no enclosing covers on either the front or backsides (normally found in superchargers). SEMI-CLOSED Built with the blades in a radial direction with an enclosing cover on the backside which extends to the periphery of the blade (normally found in air com

8、pressors). CLOSED Built with backward or forward leaning blades and has enclosing covers on both the front and backside (normally found in multi-stage centrifugal compressors). R-R uses closed impellers.,操作範圍,種類,6 段齒增速心式壓縮機,離心式壓縮機原理,離心式壓縮機利用葉輪 旋轉產生離心力來增加 氣體的速度，然後再利 用Diffuser將氣體的速度 轉換成壓力。,離心式壓縮機的結構,C

9、OMPRESSOR CASING,離心式壓縮機機殼分為三種設計: 多段式軸向分離設計 多段式徑向分離設計 單段式設計,多段式軸向分離設計,優點: 1.製造費用較低 2.於壓縮機廠房內易 於進行檢修 3.僅需少數幾種的特殊工具,多段式軸向分離設計,缺點: 1.密封面積較大 2.耐壓等級較低 3.若出入口NOZZLE位於機殼的上方，則必須移除出入口管線,多段式徑向分離設計,優點: 1.可以減少氣體洩漏 2.耐壓等級較高 3.移除轉子組時，勿須拆除出入口管線,多段式徑向分離設計,缺點: 1.價格較高 2.需要較多的特殊工具,單段式設計,優點:較多段式便宜 缺點:輸出的壓力及流量受到限制,離心式壓縮機

10、機殼的型式,1.Straight-Through Flow 般使用於低壓的製程 2.雙吸式 使用於高流量的製程,離心式壓縮機機殼的型式,3.ISO-Cooling 增加效率 將氣體溫度控制於定的 範圍內，以減少聚合物於 壓縮機內產生 2.Back to Back 在高壓的環境下，可以減少 軸向推力,COMPRESSOR ROTOR,COMPRESSOR ROTOR,葉輪,COMPRESSOR ROTOR,轉子組相關空氣動力配件,COMPRESSOR ROTOR,Interstage Impeller Eye and Shaft Seals 1.Labyrinth Style-Aluminum/

11、Stainess Steel -間隙較大較容易洩漏 -有些製程氣體無法適用 2.Abradable Style - Fluorosint / Nickel Graphite -間隙較小洩漏量較小 -適用於大部分製程氣體,COMPRESSOR ROTOR,Aluminum/Stainess Steel Labyrinth,新裝置/乾淨迷宮環 -產生擾流阻止氣體洩漏,迷宮環阻塞 -產生擾流變小導致氣體洩漏增加,迷宮環遭磨損 -間隙變大 -產生擾流變小導致氣體洩漏增加,COMPRESSOR ROTOR,Abradable Labyrinth,新的Abradable Labyrinth -產生擾流阻止

12、氣體洩漏,使用後的Abradable Labyrinth -間隙不變 -繼續產生擾流阻止氣體洩漏,Abradable Labyrinth Seal,Abradable Style,軸封,Labyrinth Seal： 用於低壓空氣壓縮機或可容許洩漏製程氣壓縮。,Steel Retaining Cartridge,Aluminum Labyrinth,Steel Sleeves,Optional Ejection or Injection Ports,Optional Buffer Gas,Contaminated Oil Drain RDS#2 B-3500),迷宮式及油膜式軸封,CL,Pro

13、cess,Iso-Sleeve Seal - Parts,Active Dry Gas Seal： 以串列式Tandem配置，緩衝氣(Buffer gas)進入乾式軸封前先以很細的過濾器過濾異物，並在軸承室與軸封室間加入隔離氮氣避免潤滑油進入軸封室。,Process Gas,軸封,乾式軸封,應用,乾.式軸封（Dry Gas Seal）,結構,Seal Oil Inlet,Buffer Gas,Rotating Seal Ring,Floating Carbon Seal Ring,Stationary Seal Ring,Shut Down Piston,Contaminated Oil Dr

14、ain,Iso Carbon Seal： 使用於中低壓。其優點： 可容許軸封油與密封油混合； 當怠速時密封油不慎關啟此時因製氣氣壓力高，Shut Down Piston加壓使轉動環與固定環密合更緊；,製程氣與軸封間可注入緩衝氣避免油進入製程側。,軸封,機械式軸封,Original Design Part Names,JOURNAL BEARING,Journal Bearings的用途: -支撐轉子組的重量和轉子組傳遞過來的力 -保持轉子組運轉的同心圓,THRUST BEARING,Thrust Bearing的用途: -吸收轉子組因壓差所產生的軸向推力 -保持轉子組於運轉時沒有軸向位移產生,

15、止推軸承(Thrust bearing)構造,COUPLING 聯軸器,Diaphragm Type - 可以高度容許因對心導致軸向及角度的偏移 - 沒有磨擦導致磨損,Steam Turbine,Steam Turbine,汽輪機(Steam Turbine),單向冷凝式：排汽低於大氣壓力,非冷凝式(或背壓式)：排汽高於大氣壓力,自動抽汽冷凝式,一、汽輪機簡介,汽輪機之分類,轉子,軸頸軸承,調速閥桿,受力止推軸承,軸頸軸承,3段隔板,非受力端止推軸承,1段葉片,2段葉片,3段葉片,2段隔板,噴嘴組,汽輪機剖面,機殼組成： 1.高壓汽櫃 (High Pressure Steam Chest) 2

16、.噴嘴環 (Nozzle Ring) 3.隔板 (Diaphragm) 4.筒身段 (Barrel Section) 5.出口機殼 (Exhaust Casing),1.,2.,4.,5.,3.,汽輪機機殼,轉子組成： 1.心轉(Shaft) 2.葉輪(IMPELLER)：由圓盤 (Disk)與動葉片(Blade)組成 3.止推圓盤(Thrust Collar),轉子與動葉片,排式壓縮機 Positive displacement compressor,性能曲線排式 vs. 動能式,Reciprocating Compressors,Reciprocating Compressors,往活式壓

17、縮機Reciprocating Compressors,Reciprocating Compressors,Compressors are used to increase the pressure of a process gas, in order to drive it into a pipeline system to an onshore process plant, to use on the producing well as gas lift, to re-inject gas for reservoir pressure maintenance and for use as

18、a fuel gas. Reciprocating compressors are used for High Pressure / Low Flow applications, where screw and centrifugal compressors cannot meet the duty.,Main Components of the Reciprocating Compressor,Cylinder(汽缸) Piston(活塞) Connecting rod(連接桿) Crankshaft(曲柄軸) Piston Pin(活塞插銷) Piston Rings(活塞環) Valves(汽閥),PV 曲線,橫臥-單作動-往式壓縮機示意圖 下圖中間是活速, 底下是汽缸 PV 圖,吸入閥與吐出閥之密封動作示意圖 轉速 400 rpm 之壓