1. Detailed Design Review P11451 Cook Stove Test Stand Group February 4 th 2011 David Sam (ME) Huseyin Zorba (ISE) Phillip Amsler (ME)

2. Agenda Project Inputs Bill of Materials Modifications to Test Stand Project Outputs Issues

3. DESIGN INPUTS

4. Customer Needs Revision #:3 Customer Need # ImportanceDescriptionComments/Status CN11 Accurate Statistical Results: Repeatable results, minimize variability and quantify uncertainty Main customer need, by minimizing variability we can achieve repeatable results and quantify our uncertainty. CN21Develop and document standardized water boil test Document a water boil test or modified water boil test with a test procedure and user manual. CN31Develop and document standardized quick stove test Create and document a quick stove test procedure for teams to test variations with instant feedback. By changing one input, user should be able to identify the impact in the output. This test should have a user manual. CN41Develop and document a field like test Create and document a test procedure to test the stove under Haitian cooking style which may include longer time to boil. Procedure should be documented with a user manual. CN51Measure efficiency and it's uncertainty Measure the efficiency of the thermal versus chemical energy used. CN61SafetyTest stand should be safe to operate for untrained users. CN71Benchmark against other stoves Test and compare our stove versus rebar stove or another kind of stove under same test conditions. This will allow comparison of results such as fuel usage, emissions, and time to boil CN81Quantify emissionsGreenhouse gases such as CO. CN92Quantify particulate matter Any solid matter output from the stove into the surrounding environment. CN102Durable Test stand should be durable and able to withstand years of testing CN112Ease of use Test stand should be ergonomic and easily used by one user. Also testing should be easily performed by an untrained user. CN122Easily transportableTest stand should be easily transportable by one user

5. Engineering Specifications Revision #:3 Engr. Spec. # ImportanceSource Specification (description) Unit of Measure Marginal Value Ideal Value Comments/Status ES11 CN1, CN2, CN3, CN4, CN7 Repeatable time to boil Standard deviation (%) <20%<10% Boiling time (mins) is an output of the WBT and customer need is to have these results be repeatable and to minimize variability ES21 CN1, CN2, CN3, CN4, CN7 Repeatable specific fuel consumption Standard deviation (%) <20%<10% Ratio of total amount of fuel (wood or charcoal) used to the amount of water (grams fuel/ grams of water) from WBT; this is a specification that can be used in benchmarking. ES31 CN1, CN2, CN3,CN4, CN5, CN7 Repeatable thermal efficiency of stove Coefficient of Variation (%) <20%<10% Ratio of the work done by heating and evaporating water to the energy consumed by the fuel source. The thermal efficiency should be repeatable to ensure validity of testing. ES41 CN1, CN2,CN3, CN4 CN7 Repeatable fuel rate consumption Standard deviation (%) <10%<5% Fuel rate consumption (g/min), by obtaining repeatable results, we can observe the differences in setting up the fuel source and lighting procedure to help us determine the best method and which is conserve fuel the best. Fuel consumption is defined as the amount of fuel to produce a unit output. (How much fuel to boil water) ES51 CN1, CN2, CN3, CN4, CN7 Repeatable firepower Standard deviation (%) <10%<5% Firepower (Watts) is the rate of fuel energy consumed by the stove per minute which can give us the power output of the stove in watts. This can be calculated from WBT data and could also be useful benchmarking. ES61 CN1, CN2, CN3, CN4, CN7, CN8 Accurate emission measurements Std Dev g (grams) <2.0 grams < 1.0 grams Based on Aprovecho WBT emission performance testing, cook stoves should emit less than 20 grams of CO and most forced air stoves emit less than 10 grams so we will look for a std dev less than 10%. (<2.0 grams) ES71CN6, CN10 Number of accidents# Accidents 1 out of 30 tests 0 Accidents relating to any burns, cuts, and shock should be zero for maximum safety during a standard WBT or any other test. This test stand must be safe for general use. ES81 CN2, CN3, CN4, CN8 User manual ease# Questions<30 Through documentation, any user should be able to read and set up the test stand and perform testing without any questions. User manual should include detailed pictures and explanations. ES92 CN1, CN2, CN3, CN4, CN7, CN9 Accurate particulate measurements Std Dev (mg)<150 mg<50 mg Based on Aprovecho WBT emission performance testing, cook stoves should emit less than 1500 grams of particulate matter so we will be looking for a std dev less than 10% (<150 mg) ES102 CN11 CN12 Set up timeminutes<20< 10 Related to ease of use, set up time for any single user should not take longer than 20 minutes. Goal would be 10 minutes from transporting stand and equipment to loading fuel and lighting fuel by one user.

6. System Level Work Inputs Test Standards a)Charcoal b)Stove (Any Kind) c)Test Type (Short, Relevant, WBT) d)Lighting Technique SYSTEMSYSTEM Outputs a)Emissions b)Solid Wastes c)Test Time d)Efficiency e)Statistical Accuracy

7. System Level Work Improvement Assessment Change in DesignWaste Management Impact Assessment EcologicalHealth Inventory Quantify:Raw Material,Energy,WastePerform the Test Goal Project Scope

8. Fish Bone

9. Risk List

10. Integrated Test Strategy Performed 1 Comparison Test – Boiling Times were found for 3 different stoves The data outputs are shared among PM’s New Tests are scheduled for the following days – Flow Rate – Skirt Size – Pot Shape

11. Bill of Materials

12. DESIGN OUTPUTS

13. Proposed Test Stand

14. Modifications on Test Stand SET-UP TIME≈ 5 MINUTES

15. Modifications for Measurement OLD NEW

16. Modifications for Measurement OLD NEW

17. Improved Functionality New thermocouple mount – New steel mount to replace previous wooden mount. Mount is also insulated to reduce impact of ambient temperatures on water temperature readings. Test stand now has two handles and larger wheels to provide easier transportation. – Test stand can be transported by one user and is very durable.

18. Improved Mass Measurements By sealing openings in the bottom of the test stand, “noise” in mass measurements have been improved. The impact of wind has a substantially smaller impact on the test stand. Mass measurements from Stovetec stove support the test stand improvements.

19. Installation of CO monitor New monitor has been installed in the exhaust stream of the test stand. It allows USB interface to recover data instead of burdening tester with recording data every minute.

20. Design Calculations

21. Convective Heat Transfer Stove q q q Assume Stove is a cylinder D~15”, H~20”  A=.6m 2 h (air free convection) range 5-10 W/m 2 K – Use 10 for conservative value T s ~600°C T ∞ range -10°C to 30°C q=h*A*(T s -T ∞ ) Hot q=3420W Cold q=3660W Δq =240W or ~5% of total output of stove (using 5kW output)

22. Use area and temperatures from previous – T s ~600°C=873K – T ∞ range -10°C to 30°C=263K to 303K – A=.6m 2 Assume Steel (ξ=.07) q=σ*ξ*A*(T s 4 -T ∞ 4 ) – σ=5.6703E-8 W/m 2 K 4 Hot q=1363W Cold q=1372W Δq=9W or ~.2% of total output of stove (using 5kW output) Radiation Heat Transfer Stove q q q

23. Turbulent Air Flow DistanceAir Velocity 1Air Velocity 2Air Velocity 3Average Air VDist (r) (in)(ft/min) (ft) 0 977.7-0.25 0.599910919521014.0-0.20833 11062105610331050.3-0.16667 1.51131105910561082.0-0.125 21074102510221040.3-0.08333 2.51076100710251036.0-0.04167 31064102710111034.00 3.5105499210251023.70.041667 4105398610271022.00.083333 4.510741026 1042.00.125 51124101610411060.30.166667 5.5990100110191003.30.208333 6 946.30.25 *inert picture of Anemometer in Chimney

24. Turbulent Air Flow Cont.

25. Volumetric Flow Calculation RingVelocity (ft/min)dA ft 2 Flow CFM 19850.060059.12 210320.049150.66 310590.038240.42 410470.027328.54 510310.016416.86 610310.00555.62 SUM201 Numerical Integration Uniform Flow Assumption Average Vel1037ft/min StdDev22.0ft/min Area0.196ft^2 Flow Rate204CFM Min199CFM Max208CFM

26. CO Output dA – When given ppm vs. time take integral using differential area with trapezoid method.

27. CO continued After integrating and taking sum of differential areas, then units = ppm*min Using standard air 1ppm CO=1.23mg CO per m 3 air. – ppm is a mass concentration of CO compared to the fluid it is in. Finally convert 204 CFM to 5.777 m 3 /min Then dA dt d(ppm)

28. Analysis

29. CO

30. In a water boil test, CO emissions should be lowest during the simmer phase, however during these three tests there is a spike or “noise” during the simmer phase in all three instances. – Hypothesis– Charcoal is shifting position during the simmer phase, creating abnormalities in CO emissions. – Test – Place stove in test stand and record emission data for Stovetec stove during combustion without pot of water. Every five minutes, stir charcoal around in stove and after recovering CO data from logger, determine if at every 5 minute interval there was a significant shift in CO emissions.

31. Water Temperature

32. Water When boiling water, a temperature between 99-100 o C should be reached to accurately determine boiling point. – Hypothesis – cold ambient temperature is impacting the thermocouple’s accuracy when collecting temperature data. The thermocouple can be modeled as a fin as heat is lost from the tip of the wire inserted into the water to the base of the thermocouple where temperature is read. – Test – With new insulated thermocouple, boil a pot of water and move the thermocouple to various locations in the pot, not just the center of the pot and observe any differences in temperature. Also note if water actually reaches 100 o C against a non-insulated thermocouple.

33. Weight-Before

34. Weight-After

35. Combined Data

36. Efficiency

37. Data Comparison

38. Issues

39. Particulate Matter Optical Light Scattering Monitoring Method Most accurate way to test emissions through light scattering monitors. Data can be benchmarked and compared with published water boil data from established laboratories. Can provide real-time results, used to analyze particulate emissions during each phase of the water boil test. Very expensive and systems can be very fragile. Depending on light scattering device, may need to take passive measurements through sampling air from the exhaust stream. Gravimetric Pump and Filter Method Through a gravimetric pump, particulate matter from a sample of the air stream is collected onto a filter. Filter is tared before measurements occur and then weighed after to obtain a total particulate mass measurement for a whole water boil test. Does not provide real time results and difficult to set up a system to determine emissions during different phases of testing. Tends to be more of a quantitative test, comparing one stove to another within our own test stand instead of benchmarking against published data.

40. Light Scattering Method Sensidyne Nephelometer Provides real time results Data logging, internal pump, selective sample rates Operating temperature, 0 – 50 Celsius $2,750.00

41. Gravimetric Pump and Filter Method Airmetrics MiniVol Users Guide Create a sample stream from exhaust and measure PM emissions Weigh the PM collected onto filters Quantitative method to compare stove emissions within our own test stand

42. Particulate Matter Testing Optical Light Scattering Monitoring Method – Most accurate way to test emissions through light scattering monitors. Data can be benchmarked and compared with published water boil data from established laboratories. – Can provide real-time results, used to analyze particulate emissions during each phase of the water boil test. – Very expensive and systems can be very fragile. – Depending on light scattering device, may need to take passive measurements through sampling air from the exhaust stream. Gravimetric Pump and Filter Method – Through a gravimetric pump, particulate matter from a sample of the air stream is collected onto a filter. – Filter is tared before measurements occur and then weighed after to obtain a total particulate mass measurement for a whole water boil test. – Does not provide real time results and difficult to set up a system to determine emissions during different phases of testing. – Tends to be more of a quantitative test, comparing one stove to another within our own test stand instead of benchmarking against published data.

43. Error Testing and Benchmarking Test a range of stoves to get an idea of variability from wind, humidity, stove size, temperature, and other variabilitys. Test other stoves (i.e.. Rebar) for emissions – Compare to published WBT data – Check if test stand has systematic or arbitrary errors If test is successfully repeatable then we will know how the P11461 stove compares.

44. Questions?