流體引起的振動(dòng)ppt課件-資料下載頁(yè)
2025-05-01 06:33本頁(yè)面
【正文】 he volumetric mass flow rate is too low relative to design conditions for a particular operating speed. 對(duì)高速離心式和軸流壓縮機(jī)而言，危害更大的問(wèn)題是喘振。發(fā)生喘振問(wèn)題的壓縮機(jī)通常是工作在設(shè)計(jì)范圍以外。在特定的運(yùn)轉(zhuǎn)速度下，當(dāng)出口壓力太高或輸送介質(zhì)的分子量較設(shè)計(jì)工況小時(shí)，壓縮機(jī)會(huì)遇到喘振問(wèn)題。 When this occurs, the gas flow will actually reverse directions in the pressors. When the surge is only minor, this flow reversal may occur only at the boundary layers of the impeller blades. However, when full surge develops, the entire fluid flow will reverse directions and will flow from the discharge to the inlet. Surge must be prevented in a pressor due to the fact that it can wreak extensive damage. 喘振發(fā)生時(shí)，壓縮機(jī)中的氣流會(huì)改變方向。當(dāng)喘振問(wèn)題輕微時(shí)，僅葉輪葉片邊界層附近的氣流會(huì)改變方向。當(dāng)喘振完全發(fā)生時(shí)，全部氣流都會(huì)改變方向，從出口流向入口。壓縮機(jī)的喘振問(wèn)題必須得到排除，因?yàn)樗鼤?huì)產(chǎn)生很大的破壞。 20220529 169。SKF Slide 19 [Code] SKF [Organisation] Surge Characteristics 喘振特點(diǎn) 1. Minor surge causes a noticeable increase at blade pass frequency and harmonics within only a time period of seconds. Such blade pass frequencies may double or even triple in amplitude. 輕微喘振僅在數(shù)秒的時(shí)間內(nèi)使葉片通過(guò)頻率及其倍頻明顯上升。葉片通過(guò)頻率幅值會(huì)上升一倍或者甚至兩倍。 2. Fully developed surge will most often lift up the entire spectrum. That is, the entire “noise floor” of the spectrum will be lifted, creating high amplitude, random response covering a broad frequency range. 完全的喘振會(huì)提高整個(gè)頻譜的底腳，即引起寬頻段、大幅值的隨機(jī)響應(yīng)。 3. Left uncorrected, surge can wreck a pressor within a short period of time. 若不加以校正，喘振能在短時(shí)間你損壞壓縮機(jī)。 20220529 169。SKF Slide 20 [Code] SKF [Organisation] Choking 流體堵塞 Choking (sometimes called “stone walling”) is essentially the opposite of surging in a pressor. Choking occurs when discharge pressures are too low creating high velocities in the diffuser section. 流體堵塞本質(zhì)上來(lái)說(shuō)是與喘振相反的故障。當(dāng)出口壓力太低導(dǎo)致流體速度太高時(shí)，壓縮機(jī)會(huì)發(fā)生流體堵塞問(wèn)題。 Vibration spectral characteristics of choking will be essentially identical to those of surging. Therefore, one will have to check other operating parameters such as pressure, mass flow, and so forth in order to differentiate which problem is occurring. 流體堵塞頻譜與喘振頻譜相同。因此故障分析人員必須監(jiān)測(cè)其它工藝參數(shù)如壓力、流量等，以確認(rèn)發(fā)生的是哪種問(wèn)題。
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