"Quvurdagi ishlab chiqarish" issiqlikgichining moddiy va termal hisobi

Issiqlik uzatish koeffitsienti:

(13)
K \u003d 1 / (1 / 5440 + 5,7310-4 + 1/1296) \u003d 109 Vt / (m2K).

3. Devor harorati:

Yechim tomondan:

tst2 \u003d t2 + tav / 2 \u003d  S; (14)

tst2 \u003d 55 + 109 (-25) / 1296 \u003d 52,9 S;
Prst2= 9,6  1ut = Vt/(m2K); (15)
Prst2=1296 (11,1/9,6) 0,25=1345 Vt/(m2K).

Suv tomondan:

tst1 \u003d t1 - Ktav / 1 \u003d  S; (16)

tst1 \u003d 30 - 109 (-25) / 5440 \u003d 30,5 C;
1 \u003d 5440 (2,21 / 2,43) 0,25 \u003d 5338 Vt / (m2K).

Issiqlik uzatish koeffitsientini aniq hisoblash:

K \u003d 1 / (1/1345 + 5,7310-4 + 1/5338) \u003d 124,66 Vt / (m2K);

Devor haroratini tekshirish:

tst1 \u003d t1 - Ktav / 1 \u003d  S; (17)

tst1 \u003d 80,0 - 124,6635 / 5338 \u003d 79,2 S.
tst2 = t2 - Ktav/2 = S; (18)
tst2 \u003d 55 + 124,66 (-25) / 1345 \u003d 52,68 S.

Olingan quvvatlar va qo'shimcha ta'minot qiymatiga yaqin.

4. Issiqlik almashinadigan sirt F = Q/ (Ktsr) =84,8103/ (124,6635) =19,44m2

5. ga mos keladigan standart qurilmani tanlashGOST 8930-78 [3.61], biz 6,0 m uzunlikdagi standart ajratilmaydigan elementlarni tanlaymiz, ular uchun issiqlik almashinuvi yuzasi 0,90 m2, keyin bir qatordagi elementlar soni:

N = F/ (nF1) =19,44/ (10,90) = 21,6 N = 22 ni qabul qiladi.

8. 2.2 Gidravlik hisoblash

Gidravlik hisoblash:

Quvurlardagi eritma tezligi: w2 = 0,55 m/s.
Nisbiy qo'pollik:

e2 = /din;

e2= 0,0002/0,040 = 0,0050;

bu erda  = 0,0002 m - quvur pürüzlülüğü [2.14]

Ishqalanish koeffitsienti. Shart bajarilganligi sababli:

/e2 = 10/0,005 = 2000 < Re2 < 560/e2 = 560/0,005 = 112000.

u holda ishqalanish koeffitsienti quyidagicha bo'ladi:

2 = 0,11 (e2 + 68/Re2) 0,25 = 0,11 (0,005 + 68/13490) 0,25 = 0,11 0,010,25;

Lg0, 010,25 = 0,25lg 0,01 = 0,25 (lg 10 - lg 10-3) = 0,25 (0 - 3) = 0,25 (- 3) = - 0,75 = 1 ,65; 1,65 = 0,4467;
2 = 0,11 0,4467 = 0,049.

Mahalliy qarshiliklar yig'indisi:

=1 + 2 + 43

=0,5 + 1,0 = 1,5;

bu erda 1 = 0,5 - quvur kirishi [2.14];

2 = 1,0 - quvurdan chiqish.

Quvur bo'shlig'ining gidravlik qarshiligi:

= Pa; (19)
(0,0496 22/0,040 + 1,5) 8780,412/2 =12044 Pa.

Nasos tanlash:

Kerakli nasos boshi:

H \u003d R / (g) \u003d 12044 / (8789,8) \u003d 1,4 m.

Volumetrik soniya iste'moli:

Q \u003d G /  \u003d 0,61 / 878 \u003d 0,00069 m3 / s.

Ushbu ikki qiymatga asoslanib, biz markazdan qochma nasosni X8/30 tanlaymiz, buning uchun quvvati Q = 2,410-3 m3/s;

bosh H = 17 m [2.38].
Halqadagi suv uchun ishqalanish koeffitsienti:
Halqadagi suvning tezligi w1= 0,60 m/s.
Nisbiy qo'pollik:

e1= /de = 0,0002/0,024 = 0,008.

Shart bajarilganligi sababli:

/e1 = 10/0,008 = 1000 < Re1 < 1250/e1 = 560/0,008 = 70000.

u holda ishqalanish koeffitsienti quyidagicha bo'ladi:

1 \u003d 0,11 (e1 + 68 / Re1) 0,25 \u003d 0,11 (0,008 + 68/17742) 0,25 \u003d 0,026;, 0120,25 \u003d \u003d 10,02 lg = 120,25 \u003d 10,02 lg (1,0792 - 3) = 0,25 (- 1,9208) = - 0,4802 = 1,3802; 1,3802 = 0,2400.

2. Mahalliy qarshiliklar yig'indisi:

=9 (1 + 2);

= 13,5;

bu erda 1 = 0,5 - quvur kirishi [2.14];

2 = 1,0 - quvurdan chiqish.

3. Halqali bo'shliqning gidravlik qarshiligi:

Pa; (20)
(0,0266 22/0,024 + 13,5) 9720,272/2 =14335 Pa.

Nasos tanlash:

Kerakli nasos boshi:

H \u003d R / (g) \u003d 14335 / (8789,8) \u003d 1,6 m.

Volumetrik soniya iste'moli:

Q \u003d G /  \u003d 0,61 / 878 \u003d 0,0026 \u003d 2,6 10-3 m3 / s.

Ushbu ikki qiymatga asoslanib, markazdan qochma nasos X8/30 ni tanlaymiz, buning uchun quvvati Q = 2,610-3 m3/s.

bosh H = 17 m [2.38]

9.