Last Updated: JW 10/10

Critical Sub-System Design

Sub-System Design

P15484 – Solar Assisted Essential Oil Distiller October 10, 2014

1. [Sub-System 1 Name]

Benchmarked Items

Be sure to add to the benchmarking document.

Concept Generation

“Mini” morph table (concept sketches) for features of the sub-system. Does not need to be extensive just show a few ideas you want to look at.

Example: different kinds of fittings that could be used, different shape containment vessel, different fastening methods, and so on

Feasibility Analysis

Criteria for selection

Questions that need to be answered

Information you need from other sub-system owners

Analyses for criteria (tables, graphs)

Be sure to save your supporting files (files that you copy paste from excel, visio, etc.) to the folder also.

Concept Selection

Reasons for elimination/

Sub-System Design

Sketches, rough solid model image

Preliminary BOM

Likely based off benchmarked items

2. Photovoltaic System

Benchmarked Items

 

Image

Name

Cost

Description

URL

Photovoltaic Panels

130 Watt Solar Panel by Sundance Solar

$329.00

130 Watts59.6" x 26.57" x 1.38"18V7.5A

http://store.sundancesolar.com/130-watt-solar-panel/

40 Watt Solar Panel by Suncance Solar

$129.95

40 Watts21.1" x 26.2" x 1.38"17.3V2.32V

http://store.sundancesolar.com/40-watt-solar-panel/

Dasol DS-A18-60, 60W 12VDC Solar Panel

$124.74

60W27.2" x 26.2" x 1.38"18V7.5APolycrystalline

http://www.gogreensolar.com/products/dasol-ds-a18-60-60w-12vdc-solar-panel

Dasol DS-A18-135, 135W Solar Panel

$207.90

135 W56.7" x 26.6" x 1.38"18V7.5APolycrstalline

http://www.gogreensolar.com/products/dasol-ds-a18-135-135w-12vdc-solar-panel?s=recomatic

130 Watt 12 Volt Solar Power Kit, SPM130P-KIT

$917.97

130W57.7 " x 26 " x 1.97 "Comes with 15 Amp 12 Volt Solar Charge Regulator

http://www.gogreensolar.com/products/130-watt-12-volt-solar-power-kit-spm130p-kit

UPG Adventure Power AP1800S2, 1800 Watt Portable Solar Power System

$1,595.00

80 W, 17.5V, 2 x 2.29A solar panel, with 1800W 120VAC PortablePower System

http://www.gogreensolar.com/products/upg-ap1800s2-1800-watt-portable-solar-power-system

Solar Power Station 60 W

$871.00

60 WBattery and cables included

http://www.selectsolar.co.uk/prod/900/solar-power-station-60w

Cabin Off-grid AC Kit 1

$1,290.00

290W

http://www.wholesalesolar.com/solarpowersystems/cabin-1-ac-off-grid-solar-kit.html

Heating Elements

24/48V DC Heating Element

$165.83

1"NPT Male

http://www.altestore.com/store/Charge-Controllers/Dump-Loads-Dump-Load-Controllers/Diversion-LoadsDump-Loads/Water-Heating-Element-for-24V-or-48V-DC-1-NPT-Male/p2327/

Submersible Water Heater Element

$34.99

600W, 12V1" NPT Male

http://www.amazon.com/Watt-Submersible-Water-Heater-Element/dp/B00KLKO12C

Submersible Water Heater Element

$39.99

6 in12V, 200, 300, or 600W

http://store.mwands.com/dc-water-heater-elements/6-inch-12-volt-dc-submersible-water-heater-element/

5 Gallon Drum Heater

 

550W, 4in wide115V 50/60Hz50 to 425 F thermostat

http://morsedrum.com/products/drum-heater.htm

Range Kleen 7361Replacement Plug-in Range Element

$8.97

6"

http://www.amazon.com/Range-Kleen-7361-Replacement-Element/dp/B000FNJ5TO/ref=zg_bs_2232395011_14

Cartridge Heaters

Varies

 

http://www.hotwatt.com/images/Web%20Page%20June%202010/Cartridge%20and%20Immersion.pdf

Heating Element Kit

$145.00

 

http://www.theelectricbrewery.com/heating-element-kits

Copper Tone Soldering Type Electric Kettle Heater

$8.25

220V, 800W

http://www.newegg.com/Product/Product.aspx?Item=9SIA4SR1SR0233

Electric Kettle Heater Replacement Kit

$15.67

220V, 3000W

http://www.amazon.com/Electric-Kettle-Heater-Element-Replacement/dp/B00A8VIRDI#productDetails

Tomlinson (Frontier/Glenray) 1906746 Warmer Element 120V 1250W 9" Dia Tomlinson Frontierglenray Kettle 341519

$67.95

120V, 1250W

http://www.amazon.com/Tomlinson-Frontier-Glenray-Frontierglenray-341519/dp/B00O193G70/ref=sr_1_37?ie=UTF8&qid=1413897408&sr=8-37&keywords=kettle+element+replacement

Stainless Steel Electric Kettle Tube Heater Element

$8.89

220V, 1500W

http://www.amazon.com/Stainless-Electric-Kettle-Heater-Element/dp/B00NCSYDKU/ref=sr_1_30?ie=UTF8&qid=1413897265&sr=8-30&keywords=kettle+element+replacement

Star Manufacturing Kettle Heating Element

$41.97

120V, 1000W

https://www.etundra.com/restaurant-parts/electrical-parts/elements/steamer/star-2n-y7413-120v-1-000w-kettle-heating-element/

Batteries

Sealed Lead Acid Battery

$66.27

12V, 35 Ah

http://www.walmart.com/ip/UPG-85980-D5722-Sealed-Lead-Acid-Batteries-12V-35-AH-UB12350/21618851

RBC3 - Sealed Lead UPS Replacement Bettery

$46.83

6V, 10Ah

http://www.batteries.com/rbc3-6v-10ah-sealed-lead-acid-ups-replacement-battery-bdrbc3-for-apc-bk600

Sealed Lead Acid Battery

$32.99

12V, 12Ah

http://www.batteries.com/12v-12ah-sealed-lead-acid-battery-with-f2-250in-terminals-uvub12120f2-for-apc-smartups-1000

Charge Controller

Renogy Tracer 4210

$209.99

Nominal System Voltage: 12V/24V Auto recognitionMax. PV Input Power: 500W (12V), 1000W (24V)Rated Charge Current: 40ARated Discharge Current: 20AMax. Solar Input Voltage: 100VDCSelf-consumption: <10mA (24V)Maximum Battery Voltage: 32VCharge Circuit Voltage Drop: ?0.26VDischarge Circuit Voltage Drop: ?0.15V

http://www.amazon.com/Renogy%C2%AE-Tracer-Charge-Controller-100VDC/dp/B00E7NI9PE

Morningstar Tristar TS-45

$146.46

45Amphttp://www.altestore.com/mmsolar/others/TriStar_DataSheet.pdf

http://www.altestore.com/store/Charge-Controllers/Solar-Charge-Controllers/PWM-Type-Solar-Charge-Controllers/Morningstar-Charge-Controllers-PWM/Morningstar-TriStar-TS-45-Charge-Controller-without-Display/p806/?gclid=CITd94qI7sECFQ9p7AodeU8AXg

Xantrex Charge Controller - C40

$112.74

40Amp12/24/48Vhttp://www.altestore.com/mmsolar/others/C-Series_Datasheet.pdf

http://www.altestore.com/store/Charge-Controllers/Solar-Charge-Controllers/PWM-Type-Solar-Charge-Controllers/Xantrex-Solar-Charge-Controllers-PWM/Xantrex-C40-Solar-Charge-Controller-40A-122448V/p2070/

Xantrex Charge Controller - C35

$88.86

35Amp12/24Vhttp://www.altestore.com/mmsolar/others/C-Series_Datasheet.pdf

http://www.altestore.com/store/Charge-Controllers/Solar-Charge-Controllers/PWM-Type-Solar-Charge-Controllers/Xantrex-Solar-Charge-Controllers-PWM/Xantrex-C35-Charge-Controller-35A-12-or-24V-Solar-Charge-Controller/p2069/

Concept Generation

1

2

3

4

Heat Water

Externally heating the chamber

NPT tapped hole in chamber

Band Heater

Submersible Heater

Criteria for selection:

1. Meets engineering requirements

2. Cost

3. Risk to project

Feasibility Analysis

Questions that need to be answered:

· Charge controller? – Stevens

· What is the minimum (or recommended) thread engagement necessary to prevent leaks?

According to CNCexpo a thread length of 1.5 times the diameter of the fastener is a good rule of thumb (http://www.cncexpo.com/ThreadEngagement.aspx).

Information other sub-system owners:

· How deep will the water be?

· What material is the boiling chamber made of?

Stainless steel.

· Will the chamber have a wall thickness or dimensions that will allow for a 1” NPT hole to be tapped with enough thread engagement to prevent leaks?

No – we need to look into modifications. Contact John Bonzo.

· What volume of water will be present in the chamber?

2.16 gallons per process minimum

· What is the diameter of the chamber?

Benchmarking shows 10-14 inches.

Concept Selection

Concept 1:

An external heating element is much less efficient than a submersible heating element and is not substantially cheaper than other heating elements.

Concept 2:

If the heating element is 0.25” in diameter (smaller than any benchmarked products) then the thread length must be 0.375” (1.5 times diameter rule of thumb). No reasonably priced vessel will have a wall thickness of 0.375”.

The wall of the vessel could be modified to provide this thickness but that would require welding and extended design time (high project risk). Instead, the male NPT threads on the heating element could be used to seal and fasten the element to the wall of the vessel.

Photovoltaic panel:

Photovoltaic panels on the market are most often sold with power specifications in Watts. During the system level design phase of the project the energy required to boil 2 gallons of water was found to be 19.3MJ, or 1.43 MJ for 0.1486 gallons of water. This energy, required each hour, results in a 397 Watt requirement before efficiency loss. The following efficiency losses are assumed:

Charge controller – 94%(“Solar…”, 2014)

Battery – 85%(“Charging…”, 2014)

Accounting for these inefficiencies, the solar panel must be able to produce 496 Watts.

All benchmarked photovoltaic panels were considered. Dividing the panel cost by Watts produced helped select the lowest cost option. $50 was added to the cost of panels not included in kits to account for additional wiring and fittings that will be required. The Dasol DS-A18-60, 60W 12VDC solar panel meets all sub-system engineering requirements at the lowest cost per Watt of all benchmarked panels. Four of these panels will be needed to produce the minimum power supply.

Battery:

A battery will be used to maintain power to the heating element during cloud cover. The team has chosen to design the sub-system to provide power for 15 minutes of cloud cover. This requires (as specified in the sub-system requirements flow-down) a battery that can provide at least 125 Wh (Wh are a standard industry measure for batteries). Charge controllers (discussed below) typically require the same voltage for both the photovoltaic panel and battery. Because a 12V panel has been selected meaning the battery must also be 12V. The 12V, 12Ah benchmarked battery is selected because it matches the voltage of the photovoltaic panel and exceeds the necessary power storage.

Charge Controller

A charge controller protects the photovoltaic system from overcharging the battery to prolong the life of the battery. The input and output voltages and amps must be specified to select a charge controller.

Module Short Circuit Current x Modules in parallel x Safety Factor = Array Short Circuit Current*

7.5A x 4 x 1.25 = 37.5A (minimum controller input current)

Total DC Connected Watts / DC System Voltage = Max. DC Load Current*

500 W / 12 V = 42 Amp (minimum controller output current)

The Morningstar Tristar TS-45 is selected because it matches these specifications.

*http://www.civicsolar.com/resource/how-size-charge-controller

Sub-System Design

Preliminary BOM

Dasol DS-A18-135, 135W Solar Panel

$207.90

X4

135 W

56.7" x 26.6" x 1.38"

18V

7.5A

Polycrstalline

http://www.gogreensolar.com/products/dasol-ds-a18-135-135w-12vdc-solar-panel?s=recomatic

Morningstar Tristar TS-45

$146.46

45Amphttp://www.altestore.com/mmsolar/others/TriStar_DataSheet.pdf

http://www.altestore.com/store/Charge-Controllers/Solar-Charge-Controllers/PWM-Type-Solar-Charge-Controllers/Morningstar-Charge-Controllers-PWM/Morningstar-TriStar-TS-45-Charge-Controller-without-Display/p806/?gclid=CITd94qI7sECFQ9p7AodeU8AXg

Sealed Lead Acid Battery

$32.99

12V, 12Ah

http://www.batteries.com/12v-12ah-sealed-lead-acid-battery-with-f2-250in-terminals-uvub12120f2-for-apc-smartups-1000

Submersible Water Heater Element

$34.99

600W, 12V1" NPT Male

http://www.amazon.com/Watt-Submersible-Water-Heater-Element/dp/B00KLKO12C

3. Methane/Propane Gas System

Benchmarked Items

 

Image

Name

Cost

Description

URL

Burner

32 Tip Round Nozzle Jet Burner

$58.50

10 in diamter150,000 BTU

http://www.amazon.com/Tip-Round-Nozzle-Burner-natural/dp/B00ADPCSMA

23 Tip Natural Gas Jet Burner

$44.99

100,000 BTU1/2" pipe inletThreaded pilot mount (pilot sold seperately)8 1/2" Dia. X 2 1/2" H

http://www.homebrewstuff.com/23-tip-natural-gas-jet-burner.html

Prime Pacific Alpine Cuisine Propane Burner, Ruglator, & Hose

$29.81

40,000 BTU13x26x5

http://www.walmart.com/ip/37193405

Camp Chef Single Burner SHP-RL

$60.99

60,000 BTU1 cast iron burnerRemovable revsible legs13"x13" cooking surface

http://www.walmart.com/ip/Camp-Chef-Single-burner-60-000-BTU-stove-SHP-RL/15422866

Bayou Classic Outdoor Patio Burner

$49.97

16"x16" cooking surface36" stainless braided hose13" tallAvailable in stainless for $91.00

http://www.walmart.com/ip/Bayou-Classic-Outdoor-Patio-Burner/19898358006bcb22a889

Brinkmann Cast Iron Burner

$51.18

100,000 BTU14.65 x 18.5 x 14.65

http://www.walmart.com/ip/Brinkmann-100-000-BTU-Cast-Iron-Burner/19898381

Buffalo Tools Sportsman Series Single Burner

$73.50

Cast iron14 x 12 x 12

http://www.walmart.com/ip/Buffalo-Tools-Sportsman-Series-Single-Burner-Portable-Gas-Stove/35630627

Portable LP Gas Buner

$79.50$144.89

35,000 BTU or 70,000 BTUOption 5 ft hose appox $327 in burner diameter8 x 13x 15 or 7.5 x 27 x 13

http://www.mcmaster.com/#=u4emx1

Tank

Empty Propane Tank

4.25lb - $77.7911lb - $82.0720lb - $45.1830lb - $77.9140lb - $115.62100lb - $176.07

1 gal2.6 gal4.7 gal7.1 gal9.4 gal23.6 gal

http://www.mcmaster.com/#propane-tanks/=u4epik

Bernzomatic Empty

$29.97

20lb

http://www.homedepot.com/b/Outdoors-Grills-Grill-Accessories-Accessories-Propane-Tanks/N-5yc1vZbx96

Worthingon Pro Grade Empty

4.5lb - $54.9711lb - $56.9730lb - $62.4740lb - $83.47100lb - $1365

 

http://www.homedepot.com/b/Outdoors-Grills-Grill-Accessories-Accessories-Propane-Tanks/N-5yc1vZbx96

Blue Rhino Pre-filled

$48.22

15lb

http://www.lowes.com/pd_7383-1592-7383_4294610332__

Combo Systems

Coleman One-Burner Propane Stove

$23.88

10,000 BTU8 in burner bowl

http://www.walmart.com/ip/20369794

Hoses, Fittings, Gauges, & Valves

Valves for Propane Tanks

20lb - $18.2830lb - $25.0840lb - $28.73100lb - $36.88

3/4" NPT inlet1 5/16" ACME type 1 and internal female POL 7/8"-14 outlet

http://www.mcmaster.com/#propane-tank-valves/=u4erfw

Propane Tank Refill Indicator Gauge

$26.65

1 5/16" female ACME type 1 inlet1 5/16" ACME type 1 and internal female POL 7/8"-14 outlet

http://www.mcmaster.com/#propane-gas-hose/=u4ewla

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Concept Generation

Due to project time constraints and the already relatively low cost, parts will be purchased rather than designed and machined.

Feasibility Analysis

Criteria for selection:

· Meets engineering requirements

· Cost

· Risk to project

Questions:

· How many hours will the operation run off propane?

No more than 4 hours per cycle. Dewi et al (http://www.geothermal-energy.org/pdf/IGAstandard/NZGW/2012/46654Final00074.pdf) indicate a 9 hour distillation process time. The solar trough is being designed to meet energy requirements operating over 2 days, or at least 10 hours of intense sunlight.

· At what rate should steam be produced?

According to Dewi et al, 2kg/hour/kg of dry vetiver root. In accordance with CR6 and S4, at least 1 pound of plant material must be processed.

· How much power must the burner produce?

BTU/HR to boil 0.6604 gallons

This energy requirement is also dependent on the change in temperature:

The BTU’s required to boil 0.1486 gallons of water in one hour is found to be:

More power is required to boil that water in less time (10 minutes):

BTU/HR to bring 0.1486 gallons to boil in 10 minutes

And even more power is required to account for efficiency:

With 20% efficiency (“Cooking…”, 2012)

8,324BTU/0.2 = 41,620 BTU

†Source: http://www.alliantgas.com/why-propane/cooking-with-propane

Information other sub-system owners:

· What volume of water will be present in the chamber?

Using a 20 quart (5 gal) vessel:

Upper limit of 2 gallons of water. The exact amount can be determined later and regulated using a float valve.

· What is the diameter of the chamber?

According to benchmarked pots and pressure cookers, the chamber will be 12-14 inches in diameter. A maximum diameter for the burner has been added to the sub-system requirements.

Concept SelectionBurner

A burner with integrated vessel resting surface is necessary to disperse flame across a wider area and to prevent the burner from potentially melting the vessel. The prime pacific alpine cuisine is the lowest cost burner benchmarked that meets all requirements.

Propane Tank

A standard 20lb propane tank is the most readily available propane tank in the local area with a low cost.

Connectors

The burner comes with integrated fittings and tubes.

Sub-System Design

Preliminary BOM

Bayou Classic Outdoor Patio Burner

$49.97

16"x16" cooking surface36" stainless braided hose13" tallAvailable in stainless for $91.00

http://www.walmart.com/ip/Bayou-Classic-Outdoor-Patio-Burner/19898358006bcb22a889

Blue Rhino Pre-filled

$48.22

15lb

http://www.lowes.com/pd_7383-1592-7383_4294610332__

4. Solar Tracker – with a focus on Tracker Sub-System Selection

Benchmarked Items

Concept Generation

Not applicable here. The information in this document is for concept selection at this stage.

Feasibility Analysis

Criteria for selection: (desired state in parentheses)

1) Cost (low)

2) Design complexity (low)

3) Further design time required (low)

4) Availability of replacement parts in Haiti (high)

5) Difficulty of repairs (low)

6) Video proof of concept (present)

7) Number of electrical components (low)

8) Water resistance (high)

9) Durable (high)

10) Manual labor required (low)

11) Level of torque it can produce (sufficient/high)

12) Reliability under occasional cloud cover (high)

13) Adapting needed for solar trough (low)

Questions that needed to be answered:

1) What will our first choice tracking be?

2) What will our backup choice tracking be?

3) Will there be enough money in the budget to support the backup plan?

Information you need from other sub-system owners:

1) How heavy will the trough be?

a. Answer: It doesn’t exactly matter if the troughs axis of rotation is also its center of mass, which means very little force will allow the trough to rotate

2) Can we reduce friction between trough axis of rotation and tracking?

Concept Selection

Our selected solar tracking concept is the Solar Flower Tracker and if this device fails in some way during the protyping phase (or any phase), we can easily resort to more reliable solar tracking methods (which may cost more and require further purchasing). Specific reasons for selection include:

See “Solar Tracking Concept Selection” spreadsheet for:

· Pugh Matrix iterations

· Full pros/ cons list

Solar Flower Tracker Selected Because:

· All Pugh Matrix iterations led to Solar Flower Tracker

· Already designed

· Plans to build available

· Low cost

· Risks have low severity

· Little time spent on designing

· Low monetary risk

· Parts are mostly ‘up-cycled’ and could potentially be found/replaced in Haiti

· Does not require any type of electricity

· No electrical maintenance/protection required

· Video proof of concept

· https://www.youtube.com/watch?v=Lva3bm3psyI

· https://www.youtube.com/watch?v=xHl-nuBpe5c&list=UUyjzaMkXTTp9P20UZbxDH6w

· Can revert to a plan “B” if prototyping fails

Other tracking devices were not selected because:

1) Pendulum Tracker

· Lots of moving parts that could potentially break and not be available in Haiti

· Not dependent on sun to control (ie: passive tracking)

· Unknown cost (lots of components to find/ purchase)

· Build intensive

2) Solar Battery Tracker

· Requires a solar battery

· Not as resistant to weather (electrical components)

3) Photodiode Battery Tracker

· Requires a battery that needs to be charged

· Not as resistant to weather (electrical components)

4) Solar Cell Tracker

· Not as resistant to weather (electrical components)

· Solar cells may be hard to find in Haiti to replace

5) Secondary Fluid with Mass Transfer

· Uses either anti-freeze or butane as the secondary fluid- could be hard to replace in Haiti and both are potentially dangerous

· Only very crude designs available

Drawbacks of Solar Flower Tracker to keep in mind:

· High complexity

· May be hard for Haitian farmers to fix if it breaks

· Requires secondary working fluid: ethanol or other alcohol based fluid

· Adds in another level of difficulty

· Maintaining fluid levels

· Reusability

· Reliability

Although some of the other methods are more widely used and tested in solar tracking than the Solar Flower method, they are more expensive and would require further design to make a reality. We will continue to further investigate the abilities and limits of the Solar Flower tracker through prototyping and through contact with the Solar Flower creator.

Our “Plan B” is the Solar Cell Tracker because it is simple, proven, and not highly design or build intensive. It also had the next best results from the Pugh Matrix iterations. There is a concern that wiring the solar cells directly to the motor may short out the cells and cause damage to the cells over a long period of time. Further investigation must be done in order to know how to avoid this problem. A simple circuit with diodes that only allow current to run in one direction may be necessary. A subject matter expert will be needed for the completion of this design. Because the Solar Flower Tracker has the potential to be very cheap, there should be money in the budget to purchase the components for the Solar Cell Tracker.

Selected Solar Tracker Sub-System Design:

(Solar Flower Tracker)

See “Sub-System Design – Solar Tracker” for more detailed designs of this sub-system.

5. [Drip Feed and Plant Matter Container]

Benchmarked Items

Concept Generation

Feasibility Analysis

Questions that need to be answered:

· Does the water need to be held in a stainless steel/copper container prior to having contact with the plant or only after the plant and water has been combined? No.

· How much water will be needed? 2.16 gal for steam + 2 gal (for condendser?) + 25% design margin = 5.2 gallons

· What is the minimum acceptable flow rate at any given time? Design so that trough can produce steam through set period of time. (~5 hours peak sunlight)

· What is the maximum acceptable flow rate that the condenser can condense?

· How much will water flow deviate as the water level decreases? (Flow for specific tube size vs. head, various curves for different tube sizes).

· Will the needle valve be able to compensate for water flow deviation? (Flow for specific tube size vs. head, various curves for different tube sizes).

· How much water will be contained in the plant matter container, how much water will be contained in the drip feed? Toilet valve possibly different.

· What is the most efficient method of directing steam past the plant material? Low press

· What is the best way to implement fittings from pot to pipe?

· Will the bronze needle fitting pose a potential chemical reaction which could decrease the quality of the oil? (Bronze is a mixture of mainly copper with some tin.) No

· Is the selective black spray paint going to have a large enough difference in solar efficiency that it would be worthwhile to purchase?

· Is it better to have a black pot exposed to sunlight or an insulated pot which will lose less heat but collect less heat? Insulate everything except for the drip feed/condenser

· Is a black pot with a selective coating a potential safety hazard?

· How much can efficiency be increased by adding fins to dump heat to surrounding environment for condenser?

Information other sub-system owners:

Steam flow out of plant matter container

Temperature? (To know when burner needs to be used) Unless there is some visual verification of steam flow.

1”NPC thread for John.

Concept Selection

Seperatory Funnel to regulate water flow/to be used as a drip feed, I thought this might be a good idea, but it is not ideal. Water would not collect as much heat from the sun, multiple seperatory funnels would be needed, and there may be potential for a chemical reaction when in contact with the PTFE.

Sub-System Design

Sketches, rough solid model image

Preliminary BOM

Likely based off benchmarked items