外文翻譯--現(xiàn)代螺桿壓縮機(jī)設(shè)計(jì)實(shí)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(jī)設(shè)計(jì)實(shí)例</p>&

41、lt;p>　　圖 5.20。螺桿壓縮機(jī)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(jī)的冷卻過(guò)程中，抽真空通過(guò)補(bǔ)氣端口。隔開(kāi)從必然導(dǎo)致在工廠的生產(chǎn)能力降低，壓縮機(jī)效率將保持不變。這樣的冷卻概念的壓縮機(jī)如圖5.23所示。</p><p>　　5.4.5 多轉(zhuǎn)子螺桿式空壓機(jī)</p><p>　　在一個(gè)螺桿式壓縮機(jī)的主要的“或”門(mén)的多個(gè)轉(zhuǎn)子的使用，以增加容量幾乎在提出這些

42、機(jī)器的引進(jìn)。如圖5.24所示。</p><p>　　5.4設(shè)計(jì)的制冷壓縮機(jī)105</p><p>　　圖5.21 。原轉(zhuǎn)子壓縮機(jī)制冷和優(yōu)化空調(diào)責(zé)任</p><p>　　表5.1 。壓縮機(jī)性能實(shí)驗(yàn)比較改造和標(biāo)準(zhǔn)轉(zhuǎn)子</p><p>　　顯示兩個(gè)門(mén)轉(zhuǎn)子 multirotor 螺桿壓縮機(jī)，作為在給定Sakun，1960年。這個(gè)想法已不尚未被全面商業(yè)

43、化。然而，幾個(gè)最近一直在專(zhuān)利，如肖，1999年和鐘，2002發(fā)表在這一領(lǐng)域。很明顯，multirotor 壓縮機(jī)的能力將多個(gè)相應(yīng)的普通絲杠的能力壓縮機(jī)。盡管如此，雖然它是相當(dāng)自我的顯而易見(jiàn)的它不是尚未充分感謝 multirotor 的機(jī)器的效率會(huì)比不好那數(shù)個(gè)單轉(zhuǎn)子雙壓縮機(jī)。</p><p>　　Multirotor 安排的另一個(gè)特點(diǎn)是平衡徑向主要轉(zhuǎn)子上的部隊(duì)。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(jī)設(shè)計(jì)實(shí)例</p><p>　　圖5.22 。優(yōu)化的轉(zhuǎn)子壓縮機(jī)和改造一般制冷稅相比原轉(zhuǎn)子（光線路）</p><p>　　5.4設(shè)計(jì)的制冷壓縮機(jī)107</p><p>　　圖5.23 。半封閉壓縮機(jī)的電機(jī)冷卻通過(guò)補(bǔ)氣端口在電機(jī)外殼，最右邊</p><p>　　圖5.24 。布局的多轉(zhuǎn)子螺桿壓縮機(jī)</p

45、><p>　　108 5現(xiàn)代螺桿壓縮機(jī)設(shè)計(jì)實(shí)例</p><p>　　同時(shí)成倍增加。一般來(lái)說(shuō)，它是軸向配合比轉(zhuǎn)子徑向力，通過(guò)使用，例如，平衡活塞。因此，這功能可被視為優(yōu)點(diǎn)。閘轉(zhuǎn)子部隊(duì)幾乎不受這種安排。</p><p><b>　　5.5多功能螺絲機(jī)</b></p><p>　　陽(yáng)性比其他類(lèi)型的螺桿機(jī)的潛在優(yōu)勢(shì)位移機(jī)是他們有能力

46、執(zhí)行壓縮擴(kuò)展等功能，同時(shí)，只使用一對(duì)轉(zhuǎn)子。進(jìn)一步特點(diǎn)，這是利用兩個(gè)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(kuò)展器和壓縮機(jī)部分。這意味著可進(jìn)行機(jī)械加工的壓縮機(jī)和膨脹機(jī)的轉(zhuǎn)子或分離地在一個(gè)單一的切割操作，然后通過(guò)機(jī)械加工在他們臨別槽完成后葉形成。此外，通過(guò)機(jī)端口的位置，如圖所示，在圖。 5.25，壓力負(fù)載可以部分的平衡，從而，機(jī)械摩擦損失將小于如果兩個(gè)函數(shù)是在單獨(dú)的機(jī)器上進(jìn)行。</p><p>　　5.5

47、.1同時(shí)壓縮和擴(kuò)展一對(duì)轉(zhuǎn)子</p><p>　　此類(lèi)機(jī)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(xì)胞，多級(jí)壓縮或膨脹，真的，任何其他應(yīng)用程序同時(shí)壓縮和擴(kuò)張是必需的。一個(gè)例子的這樣一個(gè)不尋常的，但方便的應(yīng)用是壓縮機(jī)容量控制被壓縮的氣體的部分?jǐn)U大。</p><p>　　如示5.25所示。高壓氣體進(jìn)入級(jí)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(kuò)展過(guò)程會(huì)導(dǎo)致溫度下降。然而，在這里是用來(lái)恢復(fù)的壓力降功率和使轉(zhuǎn)子轉(zhuǎn)動(dòng)。氣體進(jìn)入低壓壓氣機(jī)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(méi)有內(nèi)部?jī)?nèi)的流體輸送機(jī)之間的膨脹和壓縮部分，每次取放置在單獨(dú)的腔。</p><p>　　如果在同一臺(tái)機(jī)器示于圖5.25作為一個(gè)兩階段的壓縮機(jī)，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(jī)器頂部和將在機(jī)器

49、底部的高壓放。這提供了一個(gè)緊湊的兩階段機(jī)器可被使用，也可以在油淹沒(méi)或干燥運(yùn)行模式。類(lèi)似的安排是有效的兩個(gè)階段擴(kuò)展。</p><p>　　5.5多功能螺絲機(jī)109</p><p>　　圖5.25 。同時(shí)作用的多功能轉(zhuǎn)子壓縮機(jī)和擴(kuò)展</p><p>　　5.5.2多功能螺桿轉(zhuǎn)子設(shè)計(jì)特點(diǎn)</p><p>　　由于壓縮和膨脹分別進(jìn)行多功能轉(zhuǎn)子的壓縮機(jī)

50、和膨脹機(jī)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(gè)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(gè)完整的密封線兩個(gè)接觸表面上，這樣，可以使用相同的配置文件，無(wú)論是對(duì)膨脹機(jī)和壓縮機(jī)部分。</p><p>　　轉(zhuǎn)子齒形如何然后會(huì)出現(xiàn)圖中給出的一個(gè)例子。圖5.26 。</p><p>　　此外，擴(kuò)展部分可以包含一個(gè)容量控制，如吸幻燈片或升降閥，通過(guò)它在

51、改變音量部分負(fù)荷，容量相同的方式控制中通常使用的螺釘壓縮機(jī)。</p><p>　　如果轉(zhuǎn)子是用于多級(jí)壓縮，可以保留他們的常見(jiàn)的廓形在一個(gè)小的打擊孔螺桿壓縮機(jī)側(cè)的相對(duì)側(cè)上的一個(gè)比較大的一個(gè)。</p><p>　　110 5現(xiàn)代螺桿壓縮機(jī)設(shè)計(jì)實(shí)例</p><p>　　圖5.26 。壓縮膨脹轉(zhuǎn)子</p><p>　　5.5.3在壓縮機(jī)，膨脹機(jī)轉(zhuǎn)子上

52、的制衡力量</p><p>　　在一對(duì)壓縮機(jī)的膨脹器的安排的一個(gè)重要的新穎性轉(zhuǎn)子是在定位的端口。因?yàn)楦邏憾丝谶@樣的機(jī)器是在單元的中心，并布置成使得它們?cè)跉んw的相對(duì)側(cè)，高壓迫使由于壓縮擴(kuò)張，彼此相對(duì)，并且更重要的是，只位移彼此沿軸向由一個(gè)相對(duì)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(wú)形中平衡軸向力下面的例子在高的壓縮機(jī)和膨脹壓力的應(yīng)用程序表示的范圍內(nèi)的優(yōu)點(diǎn)，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(kāi)蒸發(fā)器和干飽和蒸汽進(jìn)入壓縮機(jī)的吸入為35巴的壓力離開(kāi)壓縮機(jī)，并進(jìn)入冷凝器的放電100巴的壓力。所需要的壓縮機(jī)轉(zhuǎn)子。將102毫米的中直徑與長(zhǎng)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(mén)但只有1.1的長(zhǎng)度/直徑比。力的計(jì)算表明什么如果制冷系統(tǒng)的設(shè)計(jì)有一個(gè)軸承負(fù)荷必須抵制傳統(tǒng)的螺桿壓縮機(jī)驅(qū)動(dòng)。僅在主轉(zhuǎn)子