Embed Size (px)
Citation preview
REDUCE MONTHLY NATURAL GAS CONSUMPTION – HVAC
Department of Mechanical Engineering, IUPUIME 414 Thermal-Fluid Systems DesignFall 2010, Professor John Toksoy
Mohammad Shams, Seyed Alireza Tabatabaei, Roozbeh Hojatpanah, Siavash Farahmand, Shahriar Ahmadi Ghoohaki
Y Statement Reduce monthly natural gas
consumption by 20% for the months of Dec thru Mar Set back temperature Insulation improvements
The Funneling Effect
Critical Input Variables
30+ Inputs
8 - 10
4 - 8
3 - 6
Found Critical X’s
Controlling Critical X’s
10 - 15
All X’s
1st “Hit List”
Screened List
MEASURE
ANALYZE
IMPROVE
CONTROL
• Process Maps
• Failure Modes and Effects Analysis
• Multi-Vari Studies
• Design of Experiments (DOE)
• Control Plans
• C&E Matrix
Does the Setup Measure Energy Consumption Accurately
For each of the 24 hr data set Calculate the heater on time Calculate heating degree days Plot HDD vs. heater on time
Does it show a linear behavior
Analysis Heater on Time vs HDD
DateTotal Heater On Time
(hrs)
Total Heater On
Time (days)
Calculated
HDD
Theoretical
HDD
Error percent
22-Jan 0.284 0.011833333 30.05351743 30 0.17839144328-Jan 1.325 0.055208333 49.58732704 48 3.30693134229-Jan 1.328 0.055333333 50.30495225 50 0.6099044973-Feb 0.828 0.0345 36.87681015 37 0.3329455534-Feb 1.0465 0.043604167 33.9020865 35 3.1368957025-Feb 1.185 0.049375 32.6507873 32 2.0337103226-Feb 1.057 0.044041667 42.25509352 41 3.061203695
Analysis Heater on Time vs HDD
Calculated HDD vs. Total Heatre On Time
y = 382.75x + 23.306R2 = 0.5049
0
10
20
30
40
50
60
0 0.01 0.02 0.03 0.04 0.05 0.06
Total Heater on Time (days)
Calc
ulat
ed H
DD
Calculated HDD
Linear (Calculated HDD)
Analysis Heater on Time vs HDD
Caculated HDD vs. Actual HDD
y = 1.0555x - 1.788R2 = 0.9906
0
10
20
30
40
50
60
0 10 20 30 40 50 60
Calculated HDD
Linear (Calculated HDD)
Analysis Error Percent of Heater on Time vs HDD
Error percent
0
0.5
1
1.5
2
2.5
3
3.5
22-Jan 28-Jan 29-Jan 3-Feb 4-Feb 5-Feb 6-Feb
Error percent
Therms Analysis
DateTotal Heater On
Time (hrs)
Total Heater On
Time (days)
Calculated
HDD
Theoretical HDD Error
percent
Energy Consumption (BTU) Energy Consumption
(Therms)22-Jan 0.284 0.011833333 30.05351743 30 0.178391 18744 0.1874428-Jan 1.325 0.055208333 49.58732704 48 3.306931 87450 0.874529-Jan 1.328 0.055333333 50.30495225 50 0.609904 87648 0.876483-Feb 0.828 0.0345 36.87681015 37 0.332946 54648 0.546484-Feb 1.0465 0.043604167 33.9020865 35 3.136896 69069 0.690695-Feb 1.185 0.049375 32.6507873 32 2.03371 78210 0.78216-Feb 1.057 0.044041667 42.25509352 41 3.061204 69762 0.69762
BTU/hr BTU Therm-8934.34 -58704867.84 -587.0486784
Total Heat loss for heating season (9 months) : (from the excel file)
BTU/hr BTU Therm-992.7044444 -6522763.093 -65.22763093
Total Heat loss for January : (from the excel file)
BTU/hr BTU Therm-32.02272401 -210411.7127 -2.104117127
Average Daily Heat Loss for January: (form the excel file)
BTU/hr BTU Therm-8934.34 -58704867.84 -587.0486784
Total Heat loss for heating season (9 months) : (from the excel file)
BTU/hr BTU Therm-992.7044444 -6522763.093 -65.22763093
Total Heat loss for February : (from the excel file)
BTU/hr BTU Therm-35.45373016 -232955.8248 -2.329558248
Average Daily Heat Loss for February: (form the excel file)
Measurement Error Error due to long signal wires Filter design
Impact on mean value
Initial Capability Initial capability
What is the current energy usage as baseline where savings will be calculated from Degree day comparison Past 5 to 10 years gas and electric bills (kWhr used not $$$)
Calculate heat loss from the house using the excel analysis tool Make the tool more general to include individual rooms
Run transient heat transfer analysis using the Matlab tool and compare to measured data
Energy Cost Estimation
Date Total Heater On Time (hrs) Total Heater On Time (days) Calculated HDD Theoretical HDD Error percent Energy Consumption (BTU) Energy Consumption (Therms) Energy Cost $
22-Jan 0.284 0.011833333 30.05351743 30 0.178391443 18744 0.18744 5745.03628-Jan 1.325 0.055208333 49.58732704 48 3.306931342 87450 0.8745 26803.42529-Jan 1.328 0.055333333 50.30495225 50 0.609904497 87648 0.87648 26864.1123-Feb 0.828 0.0345 36.87681015 37 0.332945553 54648 0.54648 16749.6124-Feb 1.0465 0.043604167 33.9020865 35 3.136895702 69069 0.69069 21169.64855-Feb 1.185 0.049375 32.6507873 32 2.033710322 78210 0.7821 23971.3656-Feb 1.057 0.044041667 42.25509352 41 3.061203695 69762 0.69762 21382.053
Results The cost for one day at
these temperatures is: $0.33
The optimal day time temperature is: 51 Degrees F
The total running time per day is: 97 Minutes
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Number of peaks =29
T_Out
T_Reg
T_Room
Humidity
Jan 22nd
Results The cost for one day at
these temperatures is: $0.13
The optimal day time temperature is: 59 Degrees F
The total running time per day is: 38 Minutes
Jan 28th
Number of peaks =51
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
T_Out
T_Reg
T_Room
Humidity
Results
The cost for one day at these temperatures is: $0.18
The optimal day time temperature is: 47 Degrees F
The total running time per day is: 53 Minutes
Jan 29th
Number of peaks =59
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
T_Out
T_Reg
T_Room
Humidity
ResultsNumber of peaks =33
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
T_Out
T_Reg
T_Room
Humidity
•The cost for one day at these temperatures is: $0.24•The optimal day time temperature is: 48 Degrees F•The total running time per day is: 71 Minutes
Feb 3rd
Results
The cost for one day at these temperatures is: $0.28
The optimal day time temperature is: 50 Degrees F
The total running time per day is: 83 Minutes
Number of peaks =48
0
10
20
30
40
50
60
70
80
90
100
0 5 10 15 20 25
T_Out
T_Reg
T_Room
Humidity
Feb 4th
Results
The cost for one day at these temperatures is: $0.27
The optimal day time temperature is: 50 Degrees F
The total running time per day is: 79 Minutes
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Number of peaks=57
T_Out
T_Reg
T_Room
Humidity
Feb 5th
Results
The cost for one day at these temperatures is: $0.22
The optimal day time temperature is: 49 Degrees F
The total running time per day is: 64 Minutes
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Number of peaks=50
T_Out
T_Reg
T_Room
Humidity
Feb 6th
HEAT EXCHANGER DESIGN
Department of Mechanical Engineering, IUPUIME 414 Thermal-Fluid Systems DesignFall 2010, Professor John Toksoy
Mohammad Shams, Seyed Alireza Tabatabaei, Roozbeh Hojatpanah, Siavash Farahmand, Shahriar Ahmadi Ghoohaki
Design Parameters Process Fluid
Water Inlet 45ºC Outlet 25ºC
City Water Inlet 20ºC
Optimal Length Less Than 7 meters
Effective VariablesEffective Variables
Tube ThicknessShell ThicknessShell Material
M-dot Tube M-dot TubeShell I/D Shell I/D
Tube Length Tube LengthCounter / Parallel
Tube O/D Tube O/DTube Material
•Due to previous iterations these nine were the variables that had the greatest effect on Weight, Length, Q, and ∆P’s
Generated Matlab File
Initial Inputs Generating
Plots of Main Effect
Pareto Charts for Optimization• Shell side pressure drop- Shell I/D had the greatest effect• Heat Exchanger overall weight- Shell I/D and Tube Length• Tube pressure drop- Mass flow rate through the tubes, Shell I/D
and Tube Length
• Shell side pressure drop- Shell I/D had the greatest effect• Heat Exchanger overall weight- Shell I/D and Tube Length• Tube pressure drop- Mass flow rate through the tubes, Shell I/D
and Tube Length
Pareto Charts for Optimization
Optimization Plot
Optimization Results
Tube Side Heat Transfer ParametersNumber of Tubes, N 4169Number of Passes 1
Tubes OD 0.0063 mTubes ID 0.0054 m
Tube Length, L 4.4000 mTube Pitch, PT 0.0079 m
Heat Transfer Coefficient, h 4158.44 W/m2.C
Shell Side Heat Transfer ParametersShell ID 0.5398 m
Shell Cross Sectional Area 0.2289 m2Shell Flow Area 0.1059 m2
Shell Equivalent Diameter 0.0046 mMass Velocity, G 1028.84 kg/m2.s
Heat Transfer Coefficient, h 4419.42 W/m2.C
Overall Heat Transfer CoefficientU (Tube outside Area) 1739.11 W/m2.C
Heat Transfer RateDesired Heat Transfer Rate 5106273.07 W
Calculated Heat Transfer Rate 5133356.91 WDifference -27083.84 W
Desired - To - Calculated Ratio 0.99
HE Pressure DropShell Side ∆P 85606.84 Pa Tube Side ∆P 8115.88 Pa
Heat Exchanger WeightTotal Weight 1362.78 kg
Adjusted Optimized Results
Tube Side Heat Transfer ParametersNumber of Tubes, N 3881Number of Passes 1
Tubes OD 0.0062 mTubes ID 0.0053 m
Tube Length, L 4.2759 mTube Pitch, PT 0.0077 m
Heat Transfer Coefficient, h 4087.62 W/m2*C
Shell Side Heat Transfer ParametersShell ID 0.5462 m
Shell Cross Sectional Area 0.2343 m2
Shell Flow Area 0.1084 m2
Shell Equivalent Diameter 0.0045 mMass Velocity, G 1006.65 kg/m2*s
Heat Transfer Coefficient, h 4383.64 W/m2*C
Overall Heat Transfer CoefficientU (Tube outside Area) 1715.16 W/m2*C
Heat Transfer RateDesired Heat Transfer Rate 5106273.07 W
Calculated Heat Transfer Rate 5163877.58 WDifference -57604.51 W
Desired - To - Calculated Ratio 0.99
HE Pressure Drop
Shell Side ∆P 85674.36 Pa
Tube Side ∆P 7956.80 Pa
Heat Exchanger Weight
Total Weight 1360.46 kg
Questions
?
