Cavitation yePombi: Theory uye Calculation
Mhedziso ye cavitation phenomenon
The pressure of liquid vaporization ndiyo vaporization pressure yemvura (saturated vapor pressure). Iyo vaporization pressure yemvura ine chekuita netembiricha. Iyo yakakwirira tembiricha, iyo yakakura iyo vaporization pressure. Iyo vaporization pressure yemvura yakachena pakamuri tembiricha ye20 ℃ ndeye 233.8Pa. Nepo iyo vaporization pressure yemvura pa100 ℃ iri 101296Pa. Naizvozvo, mvura yakachena patembiricha yekamuri (20 ℃) inotanga kunyungudika kana kudzvanywa kunodonha kusvika 233.8Pa.
Kana kudzvinyirirwa kwemvura kuchideredzwa kusvika kune vaporization pressure pane imwe tembiricha, mvura yacho inoburitsa mabubbles, anonzi cavitation. Nekudaro, iyo mhute iri mububble haisati izere mhute, asiwo ine gasi (kunyanya mweya) muchimiro chekuparara kana nucleus.
Kana mabubbles anogadzirwa panguva ye cavitation achiyerera kune yakanyanya kudzvanywa, vhoriyamu yavo inoderera uye kunyange kuputika. Chiitiko ichi chekuti mabubbles anonyangarika mumvura nekuda kwekukwira kwekumanikidza anonzi cavitation collapse.
Chiitiko che cavitation mupombi
Apo pombi iri kushanda, kana nzvimbo yemunharaunda yechikamu chayo chekufashukira (kazhinji pane imwe nzvimbo seri kwemukati we impeller blade). Nekuda kwechimwe chikonzero, kana mhedziso yekudzvinyirirwa kweiyo pumped fluid inodonha kune iyo vaporization pressure pane yazvino tembiricha, mvura inotanga kunyungudika ipapo, ichigadzira chiutsi uye kugadzira mabhuru. Mafuru aya anoyerera achienda kumberi nemvura, uye kana asvika pane imwe dzvinyiriro huru, mvura ine pressure yakakwira yakatenderedza mabubbles inomanikidza mabhuru acho kuti adzikire zvakanyanya uye kunyange kuputika. Kana bubble raputika, zvimedu zvemvura zvinozadza gomba nekumhanya zvakanyanya uye zvichidhumhana kuita sando yemvura. Ichi chiitiko chinokonzeresa kukuvadzwa kwekuora kune zvakapfuura-zvino zvikamu kana zvikaitika pamadziro akasimba.
Iyi nzira ndiyo pombi cavitation process.
Kufurira kwepombi cavitation
Gadzira ruzha uye vibration
Corrosion kukanganisa kwe-over-current components
Performance degradation
Pombi cavitation basic equation
NPSHr-Pump cavitation allowance inonziwo inodiwa cavitation allowance, uye inonzi inodiwa net positive head kunze kwenyika.
NPSHa-Iyo cavitation mvumo yemudziyo inonziwo inoshanda cavitation allowance, iyo inopihwa neiyo suction mudziyo. Iyo yakakura iyo NPSHA, iyo shoma iyo pombi ichaita cavitation. NPSha inoderera nekuwedzera kwetraffic.
Hukama pakati peNPSHa neNPSHr kana kuyerera kwachinja
Kuverengera nzira yemudziyo cavitation
hg=Pc/ρg－hc－Pv/ρg－[NPSH]
[NPSH]-Inobvumirwa cavitation mvumo
[NPSH] = (1.1 ~ 1.5) NPSHr
Kana iyo yekuyerera yakakura, tora kukosha kukuru, uye kana kuyerera kuri kudiki, tora diki kukosha.
Nguva yekutumira: Jan-22-2024