Mafala Akutoma Nawo 4) - Pampu ya Cheving Caving

Cavitation ya pampu: lingaliro ndi kuwerengera

Mwachidule za Cavitkhondo Phenomenon
Kupsinjika kwa madzi amtundu wamadzimadzi ndi kupanikizika kwamadzimadzi (zolimbitsa thupi). Kukakamizidwa kwamadzimadzi kumakhudzana ndi kutentha. Kutentha kwambiri, kupanikizika kwakukulu. Kupsinjika kwamadzi oyera kutentha kwa 2 ℃ ndi 233.8pa. Ngakhale kukakamizidwa kwamadzi ku 100 ℃ ndi 1012962a. Chifukwa chake, madzi oyera kutentha kwa firi (20 ℃) ​​imayamba kusungunula pamene kupanikizika kumatsika mpaka 233.8Pa.
Kukakamizidwa kwamadzi kumachepetsedwa ku kupanikizika kwa mpweya pa kutentha kwina, madziwo amatulutsa mapiritsi. Komabe, mpweya womwe umakhala mu bubble siyilinso nthunzi, komanso amakhala ndi mpweya (makamaka) mu mawonekedwe osungunuka kapena nyukiliya.
Mabavu omwe amapangidwa mukamatha kupanikizika kwambiri, voliyumu yawo imachepa ndipo imaphulika. Izi zimasowa kuti thovu imatha mu madzi chifukwa cha kuthamanga kumatchedwa cavitation kugwa.

Chizindikiro cha cavitation mu pampu
Pamene pampu ikugwira ntchito, ngati malo ake akomweko amasefukira (nthawi zambiri kwinakwake kumbuyo kwa tsamba la utsogoleri). Pazifukwa zina, kupanikizika kotheratu kwa madzi opopera amatsikira ku mpweya woponderezedwa kwapakatikati, madzi amayamba kutulutsa nthunzi kunja uko, kupanga nthunzi ndikupanga thovu. Mafuta awa amayenda kutsogolo ndi madzi, ndipo akamafika pachimake chachikulu, madzi opanikizika kwambiri kuzungulira thovu amakakamizidwa kwambiri komanso kuphulika. Pamene kuwira, tinthu tating'ono timene timadzaza kutalika kothamanga kwambiri ndikugundana wina ndi mnzake kuti apange nyundo yamadzi. Izi zimayambitsa kuwonongeka kwa kutukuka kwa zinthu zomwe zilipo pakadali pano zikachitika khoma lolimba.
Njira iyi ndi njira yopepuka.

Mphamvu yopumira
Kwezani phokoso komanso kugwedezeka
Kuwonongeka kwazomwe zilipo
Kuwonongeka kwa magwiridwe antchito

a

Pamping Caving Equation
NPSSSR-Pulogalamu yopumira imatchedwanso gawo lofunikira lapadera, ndipo limatchedwa kuti yofunikira net yabwino.
NPSHHHA - chilolezo cha chipangizocho chimatchedwanso chilolezo chogwiritsira ntchito chothandiza, chomwe chimaperekedwa ndi chipangizo chophatikizika. Mkulu wa NSPHHA, pampu yocheperako yomwe idzakhala yotayirira. NPHHHHHHHHHHA amachepetsa ndi kuwonjezeka kwa magalimoto.

b

Ubale pakati pa npsha ndi NTSHR mukamasintha

Njira yowerengera ya chipangizo cha chida

HG = PC / ρg-HC-PV / ρg- [NPHH]

[NPSH] - chilolezo chovomerezeka
[NPSH] = (1.1 ~ 1.5) NTSHR

Mlingo wowuma ndi waukulu, umwalire mtengo waukulu, ndipo mtengo wowuma ukakhala wocheperako, utenge mtengo wochepa.


Post Nthawi: Jan-22-2024