To download all ACMV lecuters in PDF format
www.acmv.org
 
HOME
eBooks
FORUM
Lecture
Energy Saving > Air Conditioning Systems > Approach Temperature > > www.acmv.org
Energy Saving > Air Conditioning Systems > Approach Temperature >


Untitled Document

Approach Temperature

ACMV အင္ဂ်င္နီယာတစ္ေယာက္သည္ Air Con ဘာသာရပ္ဆုိင္ရာေခၚအေဝၚမ်ားကို နားလည္သေဘာေပါက္ရန္လိုအပ္သည္။ Approch Temperature ကို ေအာက္ပါေနရာတုိ့တြင္ေတြ ့ရေလ့ရွိသည္။

က) Condenser Approach Temperature

ခ) Evaporator Approach Temperature

ဂ) Cooling Tower Approach Temperature

Approach Temperature ဆိုသည္မွာ

Approach Temperature ဆိုသည္မွာ Heat Transfer ၿဖစ္သည့္ Medium (Fluid) ႏွစ္ခုတုိ့၏ အပူခ်ိန္ၿခားနားခ်က္ၿဖစ္သည္။ အပူ(Heat)သည္ အပူခ်ိန္ၿမင့္သည့္ (High Temperature) fluid မွ အပူခ်ိန္နိမ့္သည့္ (Low Temperature) fluid သို့သာစီးဆင္းနုိင္သည္။ ထို အပူစီးဆင္းမွဳ (Heat Transfer)ၿဖစ္ရန္အတြက္ အပူခ်ိန္ကြာၿခားမွဳလုိအပ္သည္။ The Approach Temperature Difference (ATD) ၿဖစ္သည္။ Heat Exchanger မ်ားတြင္ ပူသည့္ Fluid မွ ေအးသည့္ Fluid သု့ိ အပူစီးဆင္းမွဳ (Heat Transfer)ၿဖစ္ေပၚသည္။

The Approach Temperature Difference (ATD)= ပူသည့္ Fluid ၏ အပူခ်ိန္ - ေအးသည့္ Fluid ၏ အပူခ်ိန္

Condenser Approach Temperature

Chiller ၏ condenser အတြင္း ပူသည့္ Refrigerant မွ ေအးသည့္ Condenser Water သို့ အပူစီးဆင္းမွဳ (Heat Transfer)ၿဖစ္ေပၚသည္။ ထုိေၾကာင့္

Condenser Approach Temperature = Condenser Ref Temp (31.7C @ 681.2Kpa)- Leaving Condenser Water (30.7C) = 1C ၿဖစ္သည္။

Condenser Approach Temperature = Chiller ၏Condenser အတြင္းရွိ Refrigerant ၏ အပူခ်ိန္ - Condenser ထြက္သြားသည္ Condenser Water ၏ အပူခ်ိန္ၿဖစ္သည္။

ဥပမာ- Trane Chiller အမ်ိဳးအစား ECV6E 56 ( HFC 134a) မွ နံက္ 9:45 ေမာင္းေနသည့္ Data မ်ားကို ေဖာ္ၿပထားပါသည္။

Chilled Water Set Point

6.7C

Leaving Chilled Water

6.7C

Entering Chilled Water

10.1

Entering Condenser Water

28.4C

Laving Condenser Water

30.7C

Active Control Set Point

100%

Evaporator Ref Pressure

254.2Kpa

Condenser Ref Pressure

681.2Kpa

Saturated Ref Temp

5.0C

Condenser Ref Temp

31.7C

Evaporator Approach Temp

1.6C

Condenser Approach Temp

1C

Evaporator Approach Temperature

Chiller ၏ Evaporatorအတြင္း ပူသည့္ Chiller Water မွ ေအးသည့္Refrigerant သို့ အပူစီးဆင္းမွဳ (Heat Transfer)ၿဖစ္ေပၚသည္။ ထုိေၾကာင့္

Evaporator Approach Temperature = Leaving Chilled Water (6.7C) - Evaporator Refrigerant Temp (5.0C @ 254.2Kpa)= 1.6C ၿဖစ္သည္။

Evaporator Approach Temperature = Chiller ၏ Evaporator အတြင္းမွထြက္သြားေသာ Leaving Chilled Water ၏ အပူခ်ိန္ - Chiller ၏ Evaporator အတြင္းရွိRefrigerant ၏ အပူခ်ိန္ၿဖစ္သည္။

Chiller မ်ား၏ Evaporator ႏွင့္ Condenser Approach Temperature မ်ားသည့္ 2 Degree C ထက္မေက်ာ္လြန္သင့္ေပ။ 2 Degree C ထက္ေက်ာ္လြန္ပါက chiller မ်ားသည္ လုိအပ္သည္ထက္ ပို၍ Energy ပိုသံုးစဲြသည္။ အဘယ္ေၾကာင့္ဆိုေသာ္ Leaving Chilled Water (6.7C) ရန္အတြက္ Evaporator Refrigerant Temp သည္ လုိအပ္သည္ထက္ပို၍နိမ့္ရန္လိုအပ္သည္။ နိမ့္သည့္ Evaporator Refrigerant Temp ရရန္အတြက္ Chiller Compressor သည့္ပို၍အလုပ္လုပ္ရသည္။

 

 

ေကာင္းထက္ညြန့္

Energy Saving ႏွင့္သက္ဆုိင္ေသာ ACMV Lecture မ်ား (3 Lectures)
1 Energy Saving Guide Line Energy Smart Office Read
2 Energy Saving Guide Line Energy Smart Hotel Read
3 Air Conditioning Systems Approach Temperature Read
   

www.acmv.org - Air Conditioning and Mechanical Ventilation for Young Myanmar Engineers

To download all ACMV lecuters in PDF format