外文翻譯--現(xiàn)代螺桿壓縮機設(shè)計實例

1、<p><b>　　英文原文</b></p><p>　　104 5 Examples of Modern Screw Compressor Designs</p><p>　　Fig. 5.20. Screw compressor rotors optimized for air conditioning and light refrigeration&

2、lt;/p><p>　　duty, left and rotors designed for heavy refrigeration duty, right</p><p>　　the motor cooling process is evacuated through the superfeed port. Apart from the inevitable resulting decrea

3、se in the plant capacity, the compressor efficiency will be unchanged. A compressor with such a cooling concept is shown in Fig. 5.23.</p><p>　　5.4.5 Multirotor Screw Compressors</p><p>　　The us

4、e of multiple main or gate rotors in one screw compressor to increase capacity was proposed almost at the introduction of these machines. In Fig. 5.24</p><p>　　5.4 Design of Refrigeration Compressors 105<

5、/p><p>　　Fig. 5.21. Original rotors and compressor optimized for general refrigeration and</p><p>　　air conditioning duty</p><p>　　Table 5.1. Experimental Comparison of Compressor Perf

6、ormance with Retrofit and</p><p>　　Standard Rotors</p><p>　　Standard Rotors</p><p>　　Evaporation/Condensation Temp ?15/30℃ ?35/35℃</p><p>　　Sh

7、aft Speed [rpm] 2920 2920</p><p>　　Refrig Capacity [kW] 626 216</p><p>　　Motor Power [kW]

8、 178 156</p><p>　　COP 3.523 1.383</p><p>　　Optimized Rotors</p><p>　　Evaporation/Condensation Temp

9、 ?15/30℃ ?35/35℃ 0/35℃</p><p>　　Shaft Speed [rpm] 2920 2920 2920</p><p>　　Refrig Capacity [kW] 669

10、 243 1187</p><p>　　Motor Power [kW] 182 168 245</p><p>　　COP 3.671

11、 1.486 4.98</p><p>　　COP Improvement New/Old 104.2% 107.5% -</p><p>　　a multirotor screw compressor with two gate rotors is shown, as gi

12、ven in Sakun, 1960. The idea has not yet been fully commercialised. However, several patents, such as those of Shaw, 1999 and Zhong, 2002 have been recently published in that area. It is obvious that the capacity of mult

13、irotor compressor will be a multiple the capacity of the corresponding ordinary screw compressor Nonetheless, although it is fairly self evident, it is not yet fully appreciated that the efficiency of a multirotor </p

14、><p>　　Another feature of the multirotor arrangement is the balancing of radial forces on the main rotor. Unfortunately the axial forces on the main rotor</p><p>　　106 5 Examples of Modern Screw Co

15、mpressor Designs</p><p>　　Fig. 5.22. Compressor and retrofit rotors optimized for general refrigeration duty</p><p>　　compared with the original rotors (light line)</p><p>　　5.4 Des

16、ign of Refrigeration Compressors 107</p><p>　　Fig. 5.23. Semihermetic compressor with motor cooling through superfeed port at</p><p>　　the motor housing, far right</p><p>　　Fig. 5.2

17、4. Layout of the multirotor screw compressor</p><p>　　108 5 Examples of Modern Screw Compressor Designs</p><p>　　are simultaneously multiplied. Generally, it is easier to cope with axial than wi

18、th radial rotor forces by using, for example balancing pistons. Hence this feature can be regarded as an advantage. The gate rotor forces are virtuallyunaffected by this arrangement.</p><p>　　5.5 Multifuncti

19、onal Screw Machines</p><p>　　One of the potential advantages of screw machines over other types of positivedisplacement machine is their ability to perform both the compression andexpansion functions simulta

20、neously, using only one pair of rotors. A furtherfeature of this is the use of the rotors which seal on both contacting surfaces sothat the same profile may be used both for the expander and the compressor sections. This

21、 means the compressor and expander rotors can be machined or ground in a single cutting operation and </p><p>　　5.5.1 Simultaneous Compression and Expansion</p><p>　　on One Pair of Rotors</p&

22、gt;<p>　　Fields of application of such machines are replacement of the throttle valve in refrigeration and air conditioning plants, high pressure applications, fuel cells, multistage compression or expansion and,

23、really, any other application where simultaneous compression and expansion are required. One example of such an unusual, but convenient application is compressor capacity control by partial expansion of the compressed ga

24、s.</p><p>　　As is shown in Fig. 5.25 high pressure gas enters the expander port at the top of the casing, near the centre, and is expelled from the low pressure port at the bottom of the casing at one end. T

25、he expansion process causes the temperature to drop. However, here the fall in pressure is used to recover power and causes the rotors to turn. Gas enters the low pressure compressor port, at the top of the opposite end

26、of the casing, is compressed within it and expelled from the high pressure discharge </p><p>　　If the same machine presented in Fig. 5.25 is used as a two stage compressor, only the ports of the second stage

27、 will exchange their places. The low pressure port of the second stage will be located on the top of the machine and the high pressure discharge will be at the machine bottom. This offers a compact two stage machine whic

28、h may be used either in the oil flooded or dry operation mode. A similar arrangement is valid for a two stage expander.</p><p>　　5.5 Multifunctional Screw Machines 109</p><p>　　Fig. 5.25. View o

29、f the multifunctional rotors acting simultaneously as compressor</p><p>　　and expander</p><p>　　5.5.2 Design Characteristics of Multifunctional Screw Rotors</p><p>　　Since compressi

30、on and expansion are carried out separately in multifunctional rotors the compressor and expander profiles could be different. However, this would make manufacture extremely difficult, due to the small clearance space be

31、tween the two rotor functions. Hence to make it possible for the proposed multifunctional rotors to be utilized, the rotors must form a full sealing line on both contacting surfaces so that the same profile may be used b

32、oth for the expander and the compressor secti</p><p>　　An example of how the rotor profile will then appear is given in Fig. 5.26.</p><p>　　Additionally the expansion section can contain a capac

33、ity control such as a slide or lifting valve at suction to alter the volume passing through it at part load, in a manner identical to capacity controls normally used in screw compressors.</p><p>　　If the rot

34、ors are used for multistage compression, they can retain their profile shape common for screw compressors with a small blow hole on one side and a relatively large one on the opposite side.</p><p>　　110 5 Ex

35、amples of Modern Screw Compressor Designs</p><p>　　Fig. 5.26. Compressor-Expander Rotors</p><p>　　5.5.3 Balancing Forces on Compressor-Expander Rotors</p><p>　　An important novelty

36、of the compressor expander arrangement on one pair of rotors is in the positioning of the ports. Because the high pressure ports of such machine are in the centre of the unit and arranged so that they are on opposite sid

37、es of the casing, the high pressure forces due to compression and expansion are opposed to each other and, more significantly, only displaced axially from each other by a relatively short distance. The radial forces on t

38、he bearings are thereby significantly r</p><p>　　A refrigerator uses 2.75m3/min CO2 as a working fluid which leaves the evaporator and enters the compressor as dry saturated vapour at a suction pressure of 3

39、5 bar to leave the compressor and enter the condenser at a discharge pressure of 100 bar. The compressor rotor required would be 102mm in diameter with a length/diameter ratio of 1.5. The expander required to replace a t

40、hrottle valve in this system would have a main rotor of the same diameter but with a length/diameter ratio of only 1.1. Fo</p><p><b>　　中文譯文</b></p><p>　　104 5現(xiàn)代螺桿壓縮機設(shè)計實例</p>&

41、lt;p>　　圖 5.20。螺桿壓縮機轉(zhuǎn)子為輕型制冷和空調(diào)優(yōu)化責(zé)任（左）和轉(zhuǎn)子為重型制冷責(zé)任（右）。電機的冷卻過程中，抽真空通過補氣端口。隔開從必然導(dǎo)致在工廠的生產(chǎn)能力降低，壓縮機效率將保持不變。這樣的冷卻概念的壓縮機如圖5.23所示。</p><p>　　5.4.5 多轉(zhuǎn)子螺桿式空壓機</p><p>　　在一個螺桿式壓縮機的主要的“或”門的多個轉(zhuǎn)子的使用，以增加容量幾乎在提出這些

42、機器的引進。如圖5.24所示。</p><p>　　5.4設(shè)計的制冷壓縮機105</p><p>　　圖5.21 。原轉(zhuǎn)子壓縮機制冷和優(yōu)化空調(diào)責(zé)任</p><p>　　表5.1 。壓縮機性能實驗比較改造和標(biāo)準(zhǔn)轉(zhuǎn)子</p><p>　　顯示兩個門轉(zhuǎn)子 multirotor 螺桿壓縮機，作為在給定Sakun，1960年。這個想法已不尚未被全面商業(yè)

43、化。然而，幾個最近一直在專利，如肖，1999年和鐘，2002發(fā)表在這一領(lǐng)域。很明顯，multirotor 壓縮機的能力將多個相應(yīng)的普通絲杠的能力壓縮機。盡管如此，雖然它是相當(dāng)自我的顯而易見的它不是尚未充分感謝 multirotor 的機器的效率會比不好那數(shù)個單轉(zhuǎn)子雙壓縮機。</p><p>　　Multirotor 安排的另一個特點是平衡徑向主要轉(zhuǎn)子上的部隊。不幸的是，主要的轉(zhuǎn)子軸向力</p>&l

44、t;p>　　106現(xiàn)代螺桿壓縮機設(shè)計實例</p><p>　　圖5.22 。優(yōu)化的轉(zhuǎn)子壓縮機和改造一般制冷稅相比原轉(zhuǎn)子（光線路）</p><p>　　5.4設(shè)計的制冷壓縮機107</p><p>　　圖5.23 。半封閉壓縮機的電機冷卻通過補氣端口在電機外殼，最右邊</p><p>　　圖5.24 。布局的多轉(zhuǎn)子螺桿壓縮機</p

45、><p>　　108 5現(xiàn)代螺桿壓縮機設(shè)計實例</p><p>　　同時成倍增加。一般來說，它是軸向配合比轉(zhuǎn)子徑向力，通過使用，例如，平衡活塞。因此，這功能可被視為優(yōu)點。閘轉(zhuǎn)子部隊幾乎不受這種安排。</p><p><b>　　5.5多功能螺絲機</b></p><p>　　陽性比其他類型的螺桿機的潛在優(yōu)勢位移機是他們有能力

46、執(zhí)行壓縮擴展等功能，同時，只使用一對轉(zhuǎn)子。進一步特點，這是利用兩個接觸表面上，這樣的密封轉(zhuǎn)子相同的配置文件，可以使用擴展器和壓縮機部分。這意味著可進行機械加工的壓縮機和膨脹機的轉(zhuǎn)子或分離地在一個單一的切割操作，然后通過機械加工在他們臨別槽完成后葉形成。此外，通過機端口的位置，如圖所示，在圖。 5.25，壓力負載可以部分的平衡，從而，機械摩擦損失將小于如果兩個函數(shù)是在單獨的機器上進行。</p><p>　　5.5

47、.1同時壓縮和擴展一對轉(zhuǎn)子</p><p>　　此類機器的應(yīng)用領(lǐng)域是節(jié)氣閥的更換在制冷和空調(diào)系統(tǒng)，高壓力應(yīng)用，燃料細胞，多級壓縮或膨脹，真的，任何其他應(yīng)用程序同時壓縮和擴張是必需的。一個例子的這樣一個不尋常的，但方便的應(yīng)用是壓縮機容量控制被壓縮的氣體的部分擴大。</p><p>　　如示5.25所示。高壓氣體進入級聯(lián)端口在殼體的頂部上，中心附近，從低壓排出在所述殼體的底部，在其一端的端口

48、。擴展過程會導(dǎo)致溫度下降。然而，在這里是用來恢復(fù)的壓力降功率和使轉(zhuǎn)子轉(zhuǎn)動。氣體進入低壓壓氣機口，在所述殼體的另一端的頂部，內(nèi)被壓縮和上面的底部從高壓排出口排出殼體上，中心附近。在理想的情況下，沒有內(nèi)部內(nèi)的流體輸送機之間的膨脹和壓縮部分，每次取放置在單獨的腔。</p><p>　　如果在同一臺機器示于圖5.25作為一個兩階段的壓縮機，只有端口的第二階段，將交換他們的地方。低壓力口的第二階段，將設(shè)在機器頂部和將在機器

49、底部的高壓放。這提供了一個緊湊的兩階段機器可被使用，也可以在油淹沒或干燥運行模式。類似的安排是有效的兩個階段擴展。</p><p>　　5.5多功能螺絲機109</p><p>　　圖5.25 。同時作用的多功能轉(zhuǎn)子壓縮機和擴展</p><p>　　5.5.2多功能螺桿轉(zhuǎn)子設(shè)計特點</p><p>　　由于壓縮和膨脹分別進行多功能轉(zhuǎn)子的壓縮機

50、和膨脹機配置文件也可能不同。然而，這制造非常困難的，由于小的間隙空間之間的兩個轉(zhuǎn)子的功能。因此，建議有可能使利用多功能轉(zhuǎn)子，轉(zhuǎn)子必須形成一個完整的密封線兩個接觸表面上，這樣，可以使用相同的配置文件，無論是對膨脹機和壓縮機部分。</p><p>　　轉(zhuǎn)子齒形如何然后會出現(xiàn)圖中給出的一個例子。圖5.26 。</p><p>　　此外，擴展部分可以包含一個容量控制，如吸幻燈片或升降閥，通過它在

51、改變音量部分負荷，容量相同的方式控制中通常使用的螺釘壓縮機。</p><p>　　如果轉(zhuǎn)子是用于多級壓縮，可以保留他們的常見的廓形在一個小的打擊孔螺桿壓縮機側(cè)的相對側(cè)上的一個比較大的一個。</p><p>　　110 5現(xiàn)代螺桿壓縮機設(shè)計實例</p><p>　　圖5.26 。壓縮膨脹轉(zhuǎn)子</p><p>　　5.5.3在壓縮機，膨脹機轉(zhuǎn)子上

52、的制衡力量</p><p>　　在一對壓縮機的膨脹器的安排的一個重要的新穎性轉(zhuǎn)子是在定位的端口。因為高壓端口這樣的機器是在單元的中心，并布置成使得它們在殼體的相對側(cè)，高壓迫使由于壓縮擴張，彼此相對，并且更重要的是，只位移彼此沿軸向由一個相對短的距離。上的徑向力軸承，而顯著降低。此外，由于兩端的轉(zhuǎn)子是或多或少平等的壓力，無形中平衡軸向力下面的例子在高的壓縮機和膨脹壓力的應(yīng)用程序表示的范圍內(nèi)的優(yōu)點，這是可能的從這樣

53、的安排。</p><p>　　冰箱使用2.75m3/min CO2作為工作流體離開蒸發(fā)器和干飽和蒸汽進入壓縮機的吸入為35巴的壓力離開壓縮機，并進入冷凝器的放電100巴的壓力。所需要的壓縮機轉(zhuǎn)子。將102毫米的中直徑與長度/直徑比為1.5 。需要替換的膨脹在本系統(tǒng)中，將有相同的直徑上的主轉(zhuǎn)子的節(jié)氣門但只有1.1的長度/直徑比。力的計算表明什么如果制冷系統(tǒng)的設(shè)計有一個軸承負荷必須抵制傳統(tǒng)的螺桿壓縮機驅(qū)動。僅在主轉(zhuǎn)子