·¢²¼Ê±¼ä : ÐÇÆÚËÄ ÎÄÕ»¯¹¤ÔÀí¼ÆËãÌâ½â´ð¸üÐÂÍê±Ï¿ªÊ¼ÔĶÁ
? ²»ÐèÒª±Ã,ÒºÌåÔÚѹÁ¦²îµÄ×÷ÓÃÏ¿É×Ô¶¯»ØÁ÷ÖÁËþÖÐ
18£®Ä³Ò»¸ßλ²Û¹©Ë®ÏµÍ³È總ͼËùʾ£¬¹Ü×Ó¹æ¸ñΪ¦Õ45¡Á2.5mm¡£µ±·§ÃÅÈ«¹Øʱ£¬Ñ¹Á¦±íµÄ¶ÁÊýΪ78kPa¡£µ±·§ÃÅÈ«¿ªÊ±£¬Ñ¹Á¦±íµÄ¶ÁÊýΪ75 kPa£¬ÇÒ´Ëʱˮ²ÛÒºÃæÖÁѹÁ¦±í´¦µÄÄÜÁ¿Ëðʧ¿ÉÒÔ±íʾΪ?Wf?u2J/kg£¨uΪˮÔÚ¹ÜÄÚµÄÁ÷ËÙ£©¡£ÊÔÇó£º
£¨1£©¸ßλ²ÛµÄÒºÃæ¸ß¶È£»
£¨2£©·§ÃÅÈ«¿ªÊ±Ë®ÔÚ¹ÜÄÚµÄÁ÷Á¿£¨m3/h£©¡£
½â: (1) ·§ÃÅÈ«¹Ø,Ë®¾²Ö¹
p??gh
Ìâ18 ¸½Í¼
1 h p78?103?3?7.95m ?h??g10?9.81 (2) ·§ÃÅÈ«¿ª:
ÔÚË®²Û1-1¡¯ÃæÓëѹÁ¦±í2-2¡¯Ãæ¼äÁаØŬÁ¦·½³Ì: Z1g?p1p112?u12?Z2g?2?u2??Wf ?2?2p212?u2??Wf ?2 ¼ò»¯: Z1g?75?103122?u2?u2 7.95?9.81?
10002½âÖ®: u2?1.414m/s
? Á÷Á¿: Vs??4d2u2?0.785?0.042?1.414?1.776?10?3m3/s
3 ?6.39m/h
19£®¸½Í¼ËùʾµÄÊÇÀ䶳ÑÎˮѻ·ÏµÍ³¡£ÑÎË®µÄÃܶÈΪ1100 kg/m3£¬Ñ»·Á¿Îª45 m3/h¡£¹Ü·µÄÄÚ¾¶Ïàͬ£¬ÑÎË®´ÓAÁ÷¾Á½¸ö»»ÈÈÆ÷ÖÁBµÄѹͷËðʧΪ9m£¬ÓÉBÁ÷ÖÁAµÄѹͷËðʧΪ12m£¬ÎÊ£º
£¨1£©Èô±ÃµÄЧÂÊΪ70£¥£¬Ôò±ÃµÄÖṦÂÊΪ¶àÉÙ£¿
£¨2£©ÈôA´¦Ñ¹Á¦±íµÄ¶ÁÊýΪ153kPa£¬ÔòB´¦Ñ¹Á¦±íµÄ¶ÁÊýΪ
¶àÉÙ£¿
½â: (1) ¶ÔÓÚÑ»·ÏµÍ³:
Ìâ19 ¸½Í¼
9
He??hf?9?12?21m Pe?He?Vs?g?21?45 ?ÖṦÂÊ:3600?1100?9.81?2.83kW
P?Pe??2.83?4.04kW 0.7 (2) A?BÁаØŬÁ¦·½³Ì:
pAp1212?uA?ZA?B?uB?ZB??hfAB ?g2g?g2gpAp?B?ZB??hfAB ?g?g3 ¼ò»¯:
15?3?10?pB?1100?9.81?(7?9) ?pB??19656pa(±í)
? B´¦Õæ¿Õ¶ÈΪ19656 Pa¡£
20£®25¡æË®ÔÚ¦Õ60¡Á3mmµÄ¹ÜµÀÖÐÁ÷¶¯£¬Á÷Á¿Îª20m3/h£¬ÊÔÅжÏÁ÷ÐÍ¡£
½â: ²é¸½Â¼25¡æË®ÎïÐÔ:
??996.95kg/m,3??0.903cP
20Vs3600 u???2.43m/s 20.785d0.785?0.0542 Re?du???0.054?996.95?2.43?1.45?105?4000 ?30.903?10?
ΪÍÄÁ÷
21£®Ô˶¯Õ³¶ÈΪ3.2¡Á105m2/sµÄÓлúÒºÌåÔÚ¦Õ76¡Á3.5mmµÄ¹ÜÄÚÁ÷¶¯£¬ÊÔÈ·¶¨±£³Ö¹ÜÄÚ²ãÁ÷
£
Á÷¶¯µÄ×î´óÁ÷Á¿¡£
½â: Re?du???du??2000
?umax2000?2000?3.2?10?5???0.927m/s
d0.069 ?Vmax?
?4d2umax?0.785?0.0692?0.927?3.46?10?3m3/s
10
?12.46m/h
£
22£®¼ÆËã10¡æË®ÒÔ2.7¡Á103m3/sµÄÁ÷Á¿Á÷¹ý¦Õ57¡Á3.5mm¡¢³¤20mˮƽ¸Ö¹ÜµÄÄÜÁ¿Ëðʧ¡¢Ñ¹Í·Ëðʧ¼°Ñ¹Á¦Ëðʧ¡££¨Éè¹Ü±ÚµÄ´Ö²Ú¶ÈΪ0.5mm£©
3Vs2.7?10?3??1.376m/s ½â: u?0.785d20.785?0.052 10¡æË®ÎïÐÔ:
3 ??999.7kg/m,??1.305?10?3pa?s
Re?du???0.05?999.7?1.3764?5.27?10 ?31.305?100.5?0.01
d50 ²éµÃ ??0.041
??lu2201.3762?0.041???15.53J/kg ??Wf??d20.052 ?hf??Wf/g?1.583m ?Pf??Wf???15525Pa
23£®È總ͼËùʾ£¬Óñý«Öü²ÛÖеÄijÓÍÆ·ÒÔ40m3/hµÄÁ÷Á¿ÊäËÍÖÁ¸ßλ²Û¡£Á½²ÛµÄҺλºã¶¨£¬ÇÒÏà²î20m£¬ÊäË͹ÜÄÚ¾¶Îª100mm£¬¹Ü×Ó×ܳ¤Îª45m£¨°üÀ¨ËùÓоֲ¿×èÁ¦µÄµ±Á¿³¤¶È£©¡£ÒÑÖªÓÍÆ·µÄÃܶÈΪ890kg/m3£¬Õ³¶ÈΪ0.487Pa¡¤s£¬ÊÔ¼ÆËã±ÃËùÐèµÄÓÐЧ¹¦ÂÊ¡£
½â: u?Vs?4?d2?3600?1.415m/s 0.785?0.120.1?890?1.415?258.6?2000
0.48740 Re?du?? ???6464??0.247 Re258.6Ìâ23 ¸½Í¼
ÔÚÖü²Û1½ØÃæµ½¸ßλ²Û2½ØÃæ¼äÁаØŬÁ¦·½³Ì: Z1g?p1p112?u12?We?Z2g?2?u2??Wf ?2?2¼ò»¯: We?Z2g??Wf
11
l??leu2451.4152?0.247???111.2J/kg ¶ø: ?Wf??d20.12 ?We?20?9.81?111.2?307.4J/kg Pe?We?ms?We?Vs???307.4?403600?890?3039.8W?3.04kW
24£®Ò»ÁйÜʽ»»ÈÈÆ÷£¬¿ÇÄÚ¾¶Îª500mm£¬ÄÚ×°174 ¸ù¦Õ25¡Á2.5mmµÄ¸Ö¹Ü£¬ÊÔÇó¿ÇÌåÓë¹ÜÍâ¿Õ¼äµÄµ±Á¿Ö±¾¶¡£
24?(D2?ndÍâ)D2?nd20.52?174?0.0252Íâ44???0.029m ½â: de??D?n?dÍâD?ndÍâ0.5?174?0.025??
25£®Çó³£Ñ¹ÏÂ35¡æµÄ¿ÕÆøÒÔ12m/sµÄËÙ¶ÈÁ÷¾120m³¤µÄˮƽͨ·ç¹ÜµÄÄÜÁ¿ËðʧºÍѹÁ¦Ëðʧ¡£¹ÜµÀ½ØÃæΪ³¤·½ÐΣ¬³¤Îª300mm£¬¿íΪ200mm¡££¨Éè?d£½0.0005£©
½â: µ±Á¿Ö±¾¶: de?4ab2ab2?0.3?0.2???0.24m
2(a?b)a?b0.3?0.23 35¡æ¿ÕÆøÎïÐÔ: ??1.1465kg/m,??18.85?10?6pa?s
Re? ÓÉ ?deu???0.24?1.1465?125?1.752?10 ?618.85?10d?0.0005,²éµÃ??0.019
lu2120122 ??Wf???0.019???684J/kg
de20.242
?Pf??Wf???684?1.1465?784.2Pa
26£®È總ͼËùʾ£¬ÃܶÈΪ800 kg/m3¡¢Õ³¶ÈΪ1.5 mPa¡¤s µÄÒºÌ壬Óɳ¨¿Ú¸ßλ²Û¾¦Õ114¡Á4mmµÄ¸Ö¹ÜÁ÷ÈëÒ»ÃܱÕÈÝÆ÷ÖУ¬ÆäѹÁ¦Îª0.16MPa£¨±íѹ£©£¬Á½²ÛµÄҺλºã¶¨¡£ÒºÌåÔÚ¹ÜÄÚµÄÁ÷ËÙΪ1.5m/s£¬¹Ü·ÖÐÕ¢·§Îª°ë¿ª£¬¹Ü±ÚµÄÏà¶Ô´Ö²Ú¶È?d£½0.002£¬ÊÔ¼ÆËãÁ½²ÛÒºÃæµÄ´¹Ö±¾àÀë?z¡£
½â: ÔÚ¸ßλ²Û1½ØÃæµ½ÈÝÆ÷2½ØÃæ¼äÁаØŬÁ¦·½³Ì:
Ìâ26 ¸½Í¼
12