Planification et analyse statistique d'expériences
STUDY THE EFFECTS OF THREE FACTORS ON THE OUTLET TEMPERATURE OF THE GEOTHERMAL
DOUBLE U-TUBE BOREHOLE
Under supervision of: Professor Bernard Clément
December 2009
Prepared by: Parham Eslami Nejad (1423664)
Ø Introduction
Ø What is geothermal borehole Ø Problem definition
Ø Objectives
Ø Experiment
3 o
What is geothermal borehole
o
Application (Coupled to Ground Source Heat Pump)
o
Air conditioning
o Heating
o Cooling
o
DHW heating
1 2
3
STUDY THE EFFECTS OF THREE FACTORS ON THE OUTLET TEMPERATURE OF THE GEOTHERMAL DOUBLE U-TUBE BOREHOLE
COP
o
Problems that we may encounter in Cold climate
o
Reduction in the COP
o
In extreme cases the heat pump stop operating
o
Solutions
o
Operation of the auxiliary heating (low energy efficiency)
o
Over size the borehole length ($$$)
o
???????
T
out>-6
STUDY THE EFFECTS OF THREE FACTORS ON THE OUTLET TEMPERATURE OF THE 5 GEOTHERMAL DOUBLE U-TUBE BOREHOLE
o
Problem definition
o
Avoid operation of auxiliary heating and using over sized borehole
oWhat would be the ????? solution
o
Heat injection into the borehole in the second U-tube
o
Objectives
o
Validate our calculations
o
Maximize the outlet temperature of the borehole to the heat pump
STUDY THE EFFECTS OF THREE FACTORS ON THE OUTLET TEMPERATURE OF THE 7 GEOTHERMAL DOUBLE U-TUBE BOREHOLE
o
First step
o
Many factors have an impact on the outlet temperature
o Ishikawa diagram
o
Response variable
o
Y: Borehole outlet temperature to the heat pump
o
Faxtors
o
X1: Different configurations
o
X2: Grout property
o
X3: Shank spacing
STUDY THE EFFECTS OF THREE FACTORS ON THE OUTLET TEMPERATURE OF THE 9 GEOTHERMAL DOUBLE U-TUBE BOREHOLE
o
Experimental set-up
oMethod of measurements
0°C 30°C
U-tube
STUDY THE EFFECTS OF THREE FACTORS ON THE OUTLET TEMPERATURE OF THE 11 GEOTHERMAL DOUBLE U-TUBE BOREHOLE
o
Design of experiment
o
Nonlinear relationship (according to the calculation)
o
Three levels for each factor
o
Complete factorial design (3
3=27 runs)
o
$$$$
o
Time consuming
Factors Unit Coded level
-1 0 1
X1: Different configurations - 1-2,3-4 1-3,2-4 1-2,4-3
X2: Grout property Wm
-1K
-10.8 1 1.2
X3: Shank spacing (D) m 0.005 0.017 0.033
o
Box-Behnken Design
o
Surface analysis
o
15 runs
o
Quadratic effects are included
o
Optimization
STUDY THE EFFECTS OF THREE FACTORS ON THE OUTLET TEMPERATURE OF THE 13 GEOTHERMAL DOUBLE U-TUBE BOREHOLE
o
Experimental Runs
o
Statistical analysis
STUDY THE EFFECTS OF THREE FACTORS ON THE OUTLET TEMPERATURE OF THE 15 GEOTHERMAL DOUBLE U-TUBE BOREHOLE
0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 -1.0
-0.8 -0.6 -0.4 -0.2 0.0
0.2
1-2,3-41-2,4-3 1-3,2-4
θin,hp
kb (W/mK)
Factors Expected levels to get the highest outlet
temperature X1: Different configurations 1-3,2-4
X2: Grout property 1.2
X3: Shank spacing (D) 0.005
D/rb
0.4 0.5 0.6 0.7
-1.0 -0.8 -0.6 -0.4 -0.2 0.0
0.2
1-2,3-41-2,4-3 1-3,2-4
pipes touch
each other pipes touch the borehole wall
θin,hp
