Mapping and analyzing energy use and efficiency in a modified hydroponic shipping container

145 Pages·2017·4.6 MB·English

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Open Access Theses Theses and Dissertations
8-2016
Mapping and analyzing energy use and efficiency in
a modified hydroponic shipping container
Rachel E. Sparks
Purdue University
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Graduate School Form
30Updated(cid:20)(cid:21)(cid:18)(cid:21)(cid:25)(cid:18)(cid:21)(cid:19)(cid:20)(cid:24)
PURDUE UNIVERSITY
GRADUATE SCHOOL
Thesis/Dissertation Acceptance
This is to certify that the thesis/dissertation prepared
By RachelE.Sparks
Entitled
MAPPINGANDANALYZINGENERGYUSEANDEFFICIENCYINAMODIFIEDHYDROPONICSHIPPING
CONTAINER
MasterofScienceinEngineering
For the degree of
Is approved by the final examining committee:
KeithA.Cherkauer
Co-chair
RobertM.Stwalley
Co-chair
CaryA.Mitchell
To the best of my knowledge and as understood by the student in the Thesis/Dissertation
Agreement, Publication Delay, and Certification Disclaimer (Graduate School Form 32),
this thesis/dissertation adheres to the provisions of Purdue University’s“Policy of
Integrity in Research” and the use of copyright material.
KeithA.Cherkauer,RobertM.Stwalley
Approved by Major Professor(s):
BernardA.Engel 7/20/2016
Approved by:
Head of the Departmental Graduate Program Date

MAPPING AND ANALYZING ENERGY USE AND EFFICIENCY IN A MODIFIED
HYDROPONIC SHIPPING CONTAINER
A Thesis
Submitted to the Faculty
of
Purdue University
by
Rachel E. Sparks
In Partial Fulfillment of the
Requirements for the Degree
of
Master of Science in Engineering
August 2016
Purdue University
West Lafayette, Indiana
ii

ACKNOWLEDGEMENTS
I would like to express my deepest gratitude to everyone involved in making this research
possible. First, I would like to thank my major professor and advisor, Dr. Robert M.
Stwalley III, for his guidance throughout my graduate studies. Additionally, thank you to
Dr. Keith A. Cherkauer and Dr. Cary A. Mitchell for serving on my thesis committee and
providing helpful, constructive feedback over the course of this research. I am also
indebted to EEI, Inc., Village of Hope, and the Purdue University Agricultural &
Biological Engineering Department for financial support, without which this research
would not have been achievable. Additionally, thank you to Scott Brand, Rob Eddy,
Daniel Madson, and Aaron Doke for their assistance with equipment assembly and
machinery operation and expertise. Also, thank you to John Houtman, Claire Haselhorst,
and Darren Seidel for their active participation in this research and camaraderie while
working in the laboratory together.

Many thanks to all my friends and family who supported me throughout my graduate
studies. I would especially like to thank Kale Hopper for reminding me to stay
determined and confident during difficult times. Lastly, I would like to show my great
appreciation for my parents, Diane and Joe Sparks, for always encouraging me to pursue
my dreams.
iii

TABLE OF CONTENTS
Page
LIST OF TABLES .............................................................................................................. v
LIST OF FIGURES .......................................................................................................... vii
LIST OF ABBREVIATIONS ............................................................................................ xi
ABSTRACT ...................................................................................................................... xii
CHAPTER 1. INTRODUCTION .................................................................................... 1
1.1 Background ............................................................................................................... 1
1.2 Urban Agriculture ..................................................................................................... 4
1.3 Hydroponics and Emerging Technologies ................................................................ 8
1.4 Project Motivation and Objectives .......................................................................... 13
CHAPTER 2. DESIGN AND TESTING OF THE MODIFIED HYDROPONIC
SHIPPING CONTAINER ................................................................................................ 17
2.1 Design Constraints and Goals ................................................................................. 17
2.2 Test Unit Assembly ................................................................................................. 21
2.3 Experimental Design and Procedure ....................................................................... 26
CHAPTER 3. MHSC ENERGY MODELING METHODS ......................................... 29
3.1 Theoretical Energy Modeling Components ............................................................ 29
3.2 System Energy Balance ........................................................................................... 31
iv

Page
3.3 Application of the Radiant Time Series Method ..................................................... 37
3.4 Determination of the Baseline Total Energy Load for MHSC Operation ............... 43
CHAPTER 4. RESULTS ............................................................................................... 46
4.1 Test Unit Lettuce Production Results ...................................................................... 46
4.2 RTS Method Cooling Load Results for MHSC Thermal Control .......................... 54
4.3 Baseline Total Energy Consumption Results for Full MHSC Operation ............... 63
CHAPTER 5. ANALYSIS AND DISCUSSION OF RESULTS .................................. 66
5.1 Comparison of Empirical and Theoretical Energy Use for Test Unit Components 66
5.2 Analysis of Scenarios for Improved MHSC Thermal Efficiency ........................... 71
5.3 Analysis of NFT Test Unit Plant Production Performance ..................................... 75
5.4 MHSC Crop Production Efficiency Scenarios ........................................................ 84
CHAPTER 6. CONCLUSIONS AND FUTURE CONSIDERATIONS ....................... 88
6.1 Conclusions ............................................................................................................. 88
6.2 Final Thoughts and Recommendations ................................................................... 89
LIST OF REFERENCES .................................................................................................. 94
APPENDICES
Appendix A: Additional Test Unit Images and Nutrition Information ........................... 100
Appendix B: Baseline Energy Modeling Structural Heat Transfer Information ............ 104
Appendix C: Conductive Time Series & Radiant Time Series Tables and VBA Code . 106
Appendix D: Additional 24-hour Cooling Load Results from Baseline Energy Model . 112
Appendix E: Test Unit Component Measurements and Data ......................................... 117
Appendix F: Statistical Regression Results…………………………………………….122
v

LIST OF TABLES
Table .............................................................................................................................. Page
Table 2.1: MHSC Design Elements .................................................................................. 18
Table 2.2: Varying Conditions in Test Unit...................................................................... 27
Table 3.1: Optimal Environmental Conditions for Hydroponic Lettuce Growth ............. 29
Table 3.2: Lighting, Pumping, and Ventilation Design Specifications ............................ 30
Table 3.3: Characteristics of Conduction Time Factors ................................................... 39
Table 3.4: RTS Method Radiant and Convective Splits ................................................... 41
Table 3.5: MHSC Baseline Ventilation Rates .................................................................. 44
Table 4.1: Grow Cycle Germination Rates ....................................................................... 50
Table 4.2: Grow Cycle Lettuce Yields ............................................................................. 51
Table 4.3: Total Test Unit Electricity Consumption ......................................................... 54
Table 4.4: Component Contributions to Baseline Heat Gains and Losses ....................... 59
Table 4.5: Total Monthly Baseline Power Requirements for Temperature Control ......... 61
Table 4.6: Baseline Monthly Electricity Usage by Category ........................................... 64
Table 5.1: Average Daily Experimental Electricity Use .................................................. 69
Table 5.2: Percent Error: Average Daily Experimental and Theoretical Energy Use ...... 69
Table 5.3: Baseline and Scenario 2 Ventilation Rates ...................................................... 72
Table 5.4: Percent Decrease in Monthly Energy Consumption from Baseline ................ 74
Table 5.5: Average Sample Fresh Weight for Cycles 1, 2, and 3 ..................................... 77
vi

Table .............................................................................................................................. Page
Table 5.6: Experimental Crop Production Efficiency ....................................................... 84
Table 5.7: Application of Experimental Lettuce Production to Full Scale Potential ........ 85
Table 5.8: Theoretical Full-Scale MHSC Crop Production Efficiency ............................ 86
Appendix Table
Table B.1: Thermal Resistance of MHSC Structural Materials ..................................... 104
Table B.2: ASHRAE Recommended Convective Heat Transfer Coefficients ............... 104
Table B.3: Baseline Energy Model Combined Thermal Resistances ............................. 105
Table B.4: Alternative Scenario 1 Combined Thermal Resistances ............................... 105
Table B.5: MHSC Dimensions ....................................................................................... 105
Table E.1: Test Unit Temperature and Humidity Observations March 2016 ................. 117
Table E.2: Test Unit Temperature and Humidity Observations April 2016 ................... 118
Table E.3: Test Unit Temperature and Humidity Observations May 2016 .................... 119
Table E.4: Test Unit Water Use ...................................................................................... 120
Table E.5: Test Unit Reservoir Conditions ..................................................................... 120
Table E.6: Illuminance Measurements at Each Tray Position ........................................ 121
Table F.1: Cycle 1 Regression: Sample Fresh Weight vs. Tray Position………………122
Table F.2: Cycle 2 Regression: Sample Fresh Weight vs. Tray Position………………123
Table F.3: Cycle 3 Regression: Sample Fresh Weight vs. Tray Position………………124
Table F.4: Cycle 1 Regression: Sample Fresh Weight vs. Measured Illuminance……..125
Table F.5: Cycle 2 Regression: Sample Fresh Weight vs. Measured Illuminance..........126
Table F.6: Cycle 3 Regression: Sample Fresh Weight vs. Measured Illuminance…......127
vii

LIST OF FIGURES
Figure ............................................................................................................................. Page
Figure 1.1: NFT Hydroponic Plant Production in a Greenhouse ........................................ 9
Figure 1.2: Indoor Vertical Farm, Tohoku, Japan ............................................................ 12
Figure 1.3: Freight Farms Shipping Container Exterior and Interior ............................... 14
Figure 2.1: NFT Grow Plots Profile View ........................................................................ 20
Figure 2.2: MHSC Overhead View .................................................................................. 20
Figure 2.3: Standpipe Drainage Assembly ....................................................................... 22
Figure 2.4: Overhead View AutoCAD Sketch ................................................................. 23
Figure 2.5: Overhead View Assembly .............................................................................. 23
Figure 2.6: Nose View AutoCAD Sketch ......................................................................... 24
Figure 2.7: Nose View Assembly ..................................................................................... 24
Figure 2.8: Side View AutoCAD Sketch .......................................................................... 25
Figure 2.9: Side View Assembly ...................................................................................... 25
Figure 3.1: Principle Sources of Heat Gain in Nonresidential Structures ........................ 32
Figure 3.2: Principle Sources of Heat Loss in Nonresidential Structures......................... 32
Figure 3.3: Overview of the RTS Method ........................................................................ 38
Figure 3.4: Conduction Time Series Example Calculation .............................................. 40
Figure 4.1: Cycle 1 Nursery Stage (March 28, 2016) ....................................................... 47