換熱器的計算---請教

baboon9105

最近單位上新的項目，要選擇換熱器，但是如何計算？板式和管式有啥區別？

olive3000

管式的不好，建議選用板式的。

hemei

管式的冷卻面積沒有板式冷卻面積大

天涯125

可以查閱化工版的機械設計手冊第4冊上面有詳細的介紹換熱面積的算法

13572593532

板式的換熱效率高,不過最好選擇好一些的制造廠家.小的可以用管式的劃算.

液壓青年

這得看你需要得散熱功率是多大，一般大的用板式散熱器

開達

COOLER
8 Q) b+ o' M2 s9 B% Y* s9 Q' _7 Z0 fSELECTION
& [5 M+ Z& q( ADesignation:
PV = Power loss [kW]
P01 = Specific cooling capacity [kW/°C]
V = Tank contents [l]
5 y+ |6 _0 F$ kρoil = Density of the oil [kg/l]
' t( d7 {3 i, n& z$ Zfor mineral oil: 0.915 kg/l
! N2 R% b$ t% m) A5 r1 p: X$ ZCoil = Specific heat capacity [kJ/kgK]
for mineral oil 1.88 kJ/kgK
! G+ W+ b8 C0 O7 w0 ?. ~) z∆T = Temperature increase in the
system [°C]
2 h0 h& L& D$ y2 n% H3 xt = Operating time [min]
2 K: H% Y% u8 t" gT1 = Desired oil temperature [°C]
6 t- i  F4 o- R5 G# f9 h+ s2 jT3 = Ambient temperature [°C]
Example 1:
Measurement of the power loss
on existing units and machinery.
, p, U0 y# ~) [, `  A. q& PFor this method the temperature
increase of the oil is measured
; z* t8 `/ {, b% |. E3 F  tover a certain period. The power
loss can be calculated from the
temperature increase.
Parameters:
* ?# j' N/ a" o, R% ?. l, OThe oil temperature increases
0 q$ m1 f/ f2 g. k8 [from 20 °C to 45 °C over
- p  s- _" y& T) M2 l15 minutes.
The tank contains 100 l.
Heat to be dissipated:
* Q* d. H, ?# ~  lPV =（∆T × C oil × ρoil × V）/t × 60    [kW]

PV =25 × 1.88 × 0.915 × 100 / (15 × 60 )
= 4.78 [kW]
Cooler selection:
1 a# i3 I- l2 z% R0 f) T. d– Desired oil temperature: 60 °C
; j' ]# o! F* I& }– Ambient temperature air: 30 °C

+ [8 b  K  K  O0 u5 ~6 @# {P01 =PV    /  (T1 - T3  ) [kW/°C] =0.159
A 10% safety margin is
+ j3 ?8 e3 K# w+ g  A- rrecommended to allow for
# J( d& z4 F' aelement contamination, and
" e% f+ W, B8 ^: `& ~therefore the specific power is:
0 r2 w1 ~, s. A- P; n9 I/ lP01 × 1.1 = 0.175 kW/°C.
: r4 O6 E9 P( X, V" T" ~# D; d- PThe power loss 0.175 kW/°C must
be dissipated by an oil cooler.
Suggestion:
–Cooler OK-ELH2 - 3000 rpm,
" M7 k# ?) E9 z/ Y, a) @P01 = 0.20 kW/°C at 80 l/min
. U* i: Y2 A( ~, t: l
* O6 ?+ t( B1 h# @9 G; }& K
我發了一段在上面！