inputs/givens 1.volume of ice (3.5 gal) 2.density of ice (736 kg/m 3 ) 3.latent heat of ice, h sf...
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Inputs/Givens1. Volume of Ice
(3.5 gal)2. Density of Ice
(736 kg/m3)3. Latent Heat of Ice, hsf
(333.6 KJ/kg)4. Melt time of 1 hour
(3600 s)
Constraints and Assumptions1. Steady State2. Ice can be melted in 1 hour
Output1. Cooling Load
(900 watts)
Governing Equations
Efficiency Estimation Functional Diagram: Part 1Cooling Load Required
( )900sf ice
outmelt
VhQ W
t
Inputs/Givens1. Heat Flux (900W)2. Fluid properties of air
and water
Constraints and Assumptions1. Ideal gas2. Incompressible flow3. Constant Pressure (Cp)4. Uniform Flow5. Steady State6. Ambient air Temp of 22 C and
output temp of 13 C7. Coolant temp of 0 C from ice box8. Ice can be melted in 1 hour
Output1. Air Flow Rate
(0.12 m3/s)2. Coolant Flow Rate
(1 GPM -> at least 0.5)
Governing Equations
Efficiency Estimation Functional Diagram: Part 2Fan/Pump sizing
900 ( )p airW Qc T
39000.12
( )ap air
W mQ sc T
900 ( )p coolantW Qc T
max
9000.5
( )p coolant
WQ GPM
c T
Input data1. Cooling Load
(900 watts)2. Coolant Flow rate
(1 GPM -> at least 0.5)
Constants and Knowns1. Density of Water
(1000 kg/m3)
Constraints and Assumptions1. No pumping losses2. 65% pump efficiency (low)3. Fan at 100% power4. Steady State5. 2x calculated pump power to
accommodate losses6. z (H) of coolant in pumping loop
equal to 1m (would be less in actual unit)
OutputCOP = 10
Governing Equations
Efficiency Estimation Functional Diagram: Part 3COP calculation
in
gQHW
in
CCCOP
W
Measured data1. T of water in and out
of radiator2. Win from “plug power
meter”3. Coolant Flow Rate
Constants and givens1. Area, A, of air flow2. Fluid properties of air
(density, Cp)
Constraints and Assumptions- Ideal gas- Incompressible flow- Constant Pressure (Cp)- Uniform Flow
OutputFinal/Overall COP of unit
Governing Equations
Final Efficiency Functional Diagram(Final Testing)
outCC Q VACp T
( )avg testoverall
in
CC tCOP
W
( )avgCC mean CC
Measured data1. T of water in and out
of radiator2. Win from “plug power
meter”3. Coolant Flow Rate
Constants and givens1. Area, A, of air flow2. Fluid properties of air
(density, Cp)
Constraints and Assumptions- Ideal gas- Incompressible flow- Constant Pressure (Cp)- Uniform Flow
OutputFinal/Overall COP of unit
Governing Equations
Final Efficiency Functional Diagram(Final Testing)
outCC Q VACp T
( )avg testoverall
in
CC tCOP
W
( )avgCC mean CC