KGCOE MSD Technical Review Agenda P11451: Develop Stove Test Methods and Capability: Phase II
Meeting Purpose: 1. Overview of the Project 2. Confirm its Functionality of the Design 3. Receive feedback from SME on critical technical issues 4. Receive approval from Customer to complete design as presented 5. Receive approval from Customer to purchase materials & services for project Materials to be Reviewed: 1. Team Expectations for the review 2. Team Agenda 3. Team action taken to address Action Items from the System Level Review 4. Team action taken to address shortfalls identified on Rubric feedback 5. Present enhancements in the following critical team tools 6. Present New process tools 7. Feasibility analysis from experiments 8. Preliminary Test Plan
Meeting Date: February 11, 2011, 1:00-3:00 pm Meeting Location: Room 78-2150
Meeting Timeline Start time Topic of Review Required Attendees 1:00 Introduction for the Project Professor(s) Stevens, Hanzlik, Thorn 1:02 Customer Needs Professor(s) Stevens, Hanzlik, Thorn 1:07 Engineering Specifications Professor(s) Stevens, Hanzlik, Thorn 1:10 Questions, Concerns, Ideas Professor(s) Stevens, Hanzlik, Thorn 1:15 System Level Work Professor(s) Stevens, Hanzlik, Thorn 1:18 Schedule Professor(s) Stevens, Hanzlik, Thorn 1:22 Risks Professor(s) Stevens, Hanzlik, Thorn 1:30 Questions, Concerns, Ideas Professor(s) Stevens, Hanzlik, Thorn 1:35 Bill of Materials Professor(s) Stevens, Hanzlik, Thorn 1:45 Questions, Concerns, Ideas Professor(s) Stevens, Hanzlik, Thorn 1:50 Modifications on Test Stand Professor(s) Stevens, Hanzlik, Thorn 2:00 Questions, Concerns, Ideas Professor(s) Stevens, Hanzlik, Thorn 2:05 Design Output Professor(s) Stevens, Hanzlik, Thorn 2:10 Data Acquisition Professor(s) Stevens, Hanzlik, Wellin, Thorn 2:20 Questions, Concerns, Ideas Professor(s) Stevens, Hanzlik, Wellin, Thorn 2:25 Preliminary Test Plan Professor(s) Stevens, Hanzlik, Thorn 2:30 Process Flow Chart Professor(s) Stevens, Hanzlik, Thorn 2:40 Issues Professor(s) Stevens, Hanzlik, Thorn 2:50 Questions, Concerns, Ideas Professor(s) Stevens, Hanzlik, Thorn
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Project Name: Develop Stove Test Methods and Capability: Phase II Project Number: P11451: Cook Stove Project A Project Track: Sustainable Design and Product Development Project Family: Sustainable Technologies for the Third World Faculty Guide: Rob Stevens and Ed Hanzlik Faculty Consultant: James Myers – Haiti expert, Brian Thorn – Sustainability, John Wellin – DAQ Organization: H.O.P.E (Haiti Outreach - Pwoje Espwa) Primary Contact: Rose-Marie or James Myers
Project Description
Project Background: The practice of cooking with biomass has destroyed many ecosystems. Evidence suggests an increase in the risk of common and serious diseases in users who are exposed to biomass smoke. To minimize the harmful effects associated with cooking, designing and creating a more efficient cook stove has been proposed. In conjunction with teams P11461 and P11462, P11451 will be building on P10451’s previous work to develop RIT’s capabilities to test cook stoves.
Problem Statement: The mission of P11451 is to define test methods and document testing procedures relevant to the Haitian customer needs. Also, by conducting the Water Boil Test (WBT), the test stand should be able to benchmark the RIT stove against other existing stoves. The testing process needs to have more repeatable and accurate results than the previous project team. Testing methods should quantify the stove’s fuel efficiency, cooking performance, and emissions in engineering terms.
Objectives/Scope: 1. Create and document standardized test procedures for the test stand. 2. Modify existing test stand to deliver repeatable as well as accurate emissions and efficiency results. 3. Benchmark created RIT stove against published cook stove standards.
Deliverables: 1. Functioning test stand 2. Documented testing procedure 3. Documented benchmark results against published results 4. Produce results for project teams P11461 and P11462
Expected Project Benefits: To deliver a test stand along with documented testing procedures that future MSD teams can use to benchmark existing stoves and confidently compare RIT stove performance with published data. Core Team Members: Huseyin Zorba – Project Manager Phillip Amsler David Sam
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Strategy & Approach
Assumptions & Constraints: The team must review all previous work done during last year’s stove project and improve on existing testing protocol. Expected results from a standard WBT such as efficiency, carbon monoxide, and particulate matter must be accurate and repeatable through the use of electronic sensors and standard test procedures. All laboratory equipment and test standards must met RIT EH&S Laboratory Safety Standards. OSHA Laboratory Standards can be found in 29 CR 1910.1450.
Issues & Risks: Obtaining accurate particulate matter results while meeting budget Health risks associated with cook stove testing and emissions Obtaining parts and hardware that can be integrated with current system
Action List
Item # Description A001 Start to Develop & Document Test Procedure A002 Coordinate testing with other teams A003 Add Figures & Pictures to the Procedures A004 Correction on the Description for the Flow rate A005 Differentiate the user as “Untrained” and “Trained” A006 Have a Distinct Concept
Expectations
Catch mistakes and improve design. Receive Feedback. Verify readiness to spend money and add on to current model
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Customer Needs Revision #: 4 Customer Importance Description Comments/Status Need # Accurate Statistical Results: Main customer need, by minimizing variability we can achieve CN1 1 Repeatable results, minimize variability and quantify uncertainty repeatable results and quantify our uncertainty.
Document a water boil test or modified water boil test with a test CN2 1 Develop and document standardized water boil test procedure and user manual.
Create and document a quick stove test procedure for teams to test variations with instant feedback. By changing one input, user CN3 1 Develop and document standardized quick stove test should be able to identify the impact in the output. This test should have a user manual.
Create and document a test procedure to test the stove under CN4 1 Develop and document a field like test Haitian cooking style which may include longer time to boil. Procedure should be documented with a user manual.
Measure the efficiency of the thermal versus chemical energy CN5 1 Measure efficiency and it's uncertainty used.
CN6 1 Safety Test stand should be safe to operate for untrained users.
Test and compare our stove versus rebar stove or another kind of CN7 1 Benchmark against other stoves stove under same test conditions. This will allow comparison of results such as fuel usage, emissions, and time to boil
CN8 1 Quantify emissions Greenhouse gases such as CO.
Any solid matter output from the stove into the surrounding CN9 2 Quantify particulate matter environment. Test stand should be durable and able to withstand years of CN10 2 Durable testing Test stand should be ergonomic and easily used by one user. CN11 2 Ease of use Also testing should be easily performed by an untrained user. CN12 2 Easily transportable Test stand should be easily transportable by one user
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Engineering Specifications Revision #: 4 Engr. Unit of Marginal Ideal Importance Source Specification (description) Comments/Status Spec. # Measure Value Value
CN1, CN2, Standard Boiling time (mins) is an output of the WBT and customer need is to Repeatable time to boil <20% <10% CN3, CN4, deviation (%) have these results be repeatable and to minimize variability ES1 1 CN7 Ratio of total amount of fuel (wood or charcoal) used to the amount of CN1, CN2, Repeatable specific fuel Standard <20% <10% water (grams fuel/ grams of water) from WBT; this is a specification CN3, CN4, consumption deviation (%) ES2 1 CN7 that can be used in benchmarking. Ratio of the work done by heating and evaporating water to the energy CN1, CN2, Repeatable thermal efficiency of Coefficient of <20% <10% consumed by the fuel source. The thermal efficiency should be CN3,CN4, stove Variation (%) ES3 1 CN5, CN7 repeatable to ensure validity of testing. Fuel rate consumption (g/min), by obtaining repeatable results, we can observe the differences in setting up the fuel source and lighting Repeatable fuel rate Standard <10% <5% procedure to help us determine the best method and which is conserve CN1, consumption deviation (%) CN2,CN3, fuel the best. Fuel consumption is defined as the amount of fuel to ES4 1 CN4 CN7 produce a unit output. (How much fuel to boil water) Firepower (Watts) is the rate of fuel energy consumed by the stove per Standard minute which can give us the power output of the stove in watts. This CN1, CN2, Repeatable firepower <10% <5% CN3, CN4, deviation (%) can be calculated from WBT data and could also be useful ES5 1 CN7 benchmarking. CN1, CN2, Based on Aprovecho WBT emission performance testing, cook stoves Accurate emission CN3, CN4, Std Dev % <20% < 10% should emit less than 20 grams of CO and most forced air stoves emit measurements ES6 1 CN7, CN8 less than 10 grams so we will look for a std dev less than 10%. Accidents relating to any burns, cuts, and shock should be zero for 1 out of Number of accidents # Accidents 0 maximum safety during a standard WBT or any other test. This test 30 tests ES7 1 CN6, CN10 stand must be safe for general use. Through documentation, any user should be able to read and set up the CN2, CN3, User manual ease # Questions <3 0 test stand and perform testing without any questions. User manual ES8 1 CN4, CN8 should include detailed pictures and explanations. Based on Aprovecho WBT emission performance testing, cook stoves CN1, CN2, Accurate particulate Std Dev % <20% <10% should emit less than 1500 grams of particulate matter so we will be CN3, CN4, measurements ES9 2 CN7, CN9 looking for a std dev less than 10%. Related to ease of use, set up time for any single user should not take CN11 Set up time minutes <20 < 10 longer than 20 minutes. Goal would be 10 minutes from transporting ES10 2 CN12 stand and equipment to loading fuel and lighting fuel by one user. KGCOE MSD Page 5 of 31 Technical Review
System Level Work
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Work Breakdown Structure
STOVE
11461 11462 11451 Testing Group
Test Emissions Safety Results Efficiency Test Stand Procedure (David) (Whole Group) (David) (Phil) (Huseyin) (Huseyin)
Easily Particulate Statistically Standardized CO Proper Material Accurate Uncertainty Accuracy Durability Usability Ergonomics Followed Matter Handling Repeatable
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Fishbone Diagram
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Schedule
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Risk List
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Bill of Materials
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Proposed Test Stand
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Current Test Stand
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Modifications for Measurement
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Improvement to Measurements Improved Functionality New thermocouple mount o 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. o Test stand can be transported by one user and is very durable. 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. Improved Carbon Monoxide Measurements 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.
DESIGN OUTPUT Feasibility Analysis Analysis on StoveTec from 01/28 and 01/31
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When boiling water, a temperature between 99-100 oC 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 oC against a non-insulated thermocouple.
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Graph corresponding to the Weight data before improvements were made to the test stand
Graph corresponding to the Weight data after improvements were made to the test stand
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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.
Efficiency Output
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Data Acquisition Desired Outputs Measured Quantity Acquisition Method Efficiency H2O Temp, Mass Thermal couple with data logging Scale with operator recording (written notes) CO Emissions PPM, Flow Rate EL-USB-CO data logging device Hot wire anemometer with uniform flow assumption. Particulate Emissions Mass WIP
As of now the only device that still requires human interaction is the scale. We would like to acquire a scale which is capable of RS232 output to a computer. With this we could read data at a maximum rate of 1 reading every 10 seconds (limited by CO monitor).
Efficiency
(mwater * cp * Twater) (mevaporated * LHwater) Efficiency (m fuel * HVfuel ) (mbutane * HVbutane )
Known values for the Efficiency are: Heat Capacity of Water(cp), Latent Heat (LH) of Water, Heating Value (HV) of charcoal, and Heating Value of butane. To calculate Efficiency we need: mwater, Water Temperatures, mevaportated, mfuel, mbutane. o All of this data comes from measurement devices as well as initial and final test measurements.
CO Emissions First, we need to calculate the flow rate within the chimney. To do this we took readings of the flow rate versus position in the chimney. The results are in the table below. Distance Air Velocity 1 Air Velocity 2 Air Velocity 3 Average Air V Dist (r) (in) (ft/min) (ft/min) (ft/min) (ft/min) (ft) 0 977.7 -0.25 0.5 999 1091 952 1014.0 -0.20833 1 1062 1056 1033 1050.3 -0.16667 1.5 1131 1059 1056 1082.0 -0.125 2 1074 1025 1022 1040.3 -0.08333 2.5 1076 1007 1025 1036.0 -0.04167 3 1064 1027 1011 1034.0 0 3.5 1054 992 1025 1023.7 0.041667 4 1053 986 1027 1022.0 0.083333 4.5 1074 1026 1026 1042.0 0.125 5 1124 1016 1041 1060.3 0.166667 5.5 990 1001 1019 1003.3 0.208333 6 946.3 0.25
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Flow Rate 1200
1000
800 Air Velocity 1
600 Air Velocity 2
400 Air Velocity 3
Fluid Velocity Velocity Fluid (ft/min) Average Air V 200 Average Vel
0 -0.25 -0.2 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 Distance from Center (ft)
Flow is then calculated using numerical integration and uniform flow in the tables below.
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After using trapezoid rule to integrate, take the sum of differential areas. Units = ppm*min Using standard air 1ppm CO=1.23mg CO per m3 air. o ppm is a mass concentration of CO compared to the fluid it is in. Finally convert 204 CFM to 5.777 m3 /min
1.23[mgCO/ m3air] Then m[CO] Area[ ppm*min]* *5.777[m3air / min] [ ppm]
Particulate Matter Testing
Particulate matter testing is a necessity when comparing cook stoves to one another for not only efficiency data but also because particulate matter is a danger to cook stove operators. Particulate matter has short and long term effects on people and can be difficult to measure and quantify. Challenges
There are many challenges to testing particulate matter from cook stoves within an exhaust system. Combustion is an unsteady process thus taking one measurement of particulate matter would be an understatement or overstatement of the emissions. Particulate matter testing should be broken up into time intervals to watch the change in emissions over the combustion process.
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Particulate matter can change physical states depending on temperature. “Semi-volatile organic compounds” take the form of gas vapor and can flow through filtering systems. These particulates change into solid particles as the exhaust is cooled down. Stove exhaust is not dry, it can contain water and fuel and as exhaust cools down, it condenses to water. This condensation can damage particulate measurement and impact any gravimetric sampling process that involves filtering and weighing. Goals
These are the overall goals of a standard water boil test for emissions and particulate matter testing. Sampling over the entire test and burn cycle (One absolute value) Sampling over different combustion phases (Numerous data points) Relate emissions to fuel burned (grams of particulate/grams of charcoal) Methods
Since employing an optical light monitor as a measurement tool for our test stand has been eliminated as an option. (Outside budget) We need to change our method to a gravimetric measurement system, where we attempt to capture particulate matter onto a filter and measure how much matter was collected (mg) during a test. However this now brings up a new decision. Whether we can capture the total amount of particulate matter emitted from the exhaust and eventually qualitatively benchmark our tested stoves with published data. Or capture a sample of the exhaust stream and quantitatively compare and rank only the stoves tested within our test stand.
Sampling Entire Exhaust Stream
By sampling the entire exhaust stream for particulate matter we can obtain an absolute value for comparison. We can compare a stove’s total particulate matter output to published data.
Ideas & Concepts
One idea to capture total particulate matter emitted would be to implement an expansion downstream of the test stand’s exhaust blower. By creating an expansion and knowing the equation…
We can slow down the velocity through an expansion and let aerodynamically challenged particulate matter settle onto a filter.
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Figure 1. Expansion We can also implement a baffle chamber after our blower, which also uses the idea of an expansion with a fixed plate.
Figure 2. Baffle Chamber
The baffle chamber uses the sudden expansion to slow down the exhaust and by chamber the path of the exhaust stream, large particulate matter particles do not follow the exhaust path and simply settle.
Advantages
Easy to implement and integrate into our test stand. Can obtain an absolute value for total particulate matter by collected settling particles. No moving parts in collection process. Disadvantages
No real time results, can’t analyze different stages of combustion for more detailed results. According to the EPA, only large particles with diameters of 75 µm and larger would settle. Semi-volatile organic compounds will not settle within an expansion chamber. Conclusion
This method is an acceptable pre-cleaning/filtering method but not an accurate way to collect a measurable amount of particulate matter. For cook stove comparisons, particulate matter with a diameter equal or less than 2.5 µm are measured since these particles have the biggest impact KGCOE MSD Page 23 of 31 Technical Review
on stove operator’s respiratory systems and can have long term health impacts. Also this process does not help us monitor particulate matter emitted during different stages of combustion, when in reality most particulate matter is emitted during the start-up stage of a stove. Sampling Percentage of Exhaust Stream
By sampling a percentage of the main exhaust stream, we can quantitatively rank our tested stoves amongst one another. By sampling a known volumetric flow rate and over a specific time interval, we can obtain a rank comparison. Sample Data
60
50
40
30 Sample Stove 1 20 Sample Stove 2
10 ParticulateMatter (mg)
0 0 10 20 30 40 Time (mins)
Figure 3. Sample data to provide a rank comparison.
By filtering particulate matter at an example time interval, 1 minute, 5 minute, 10 minute and etc., we can break up the emissions during the combustion phase and rank our stoves on overall emissions and emissions during start up and simmer phases.
Ideas & Concepts Based on work done by MSD teams 10056 (Side Stream Smoke Collection Systems) and 10451 (Last year’s Stove Testing team), we can explore vacuum pump and filter options. Using a Cambridge filter and gasket system from team 10056, we can use this filter to collect particulate matter downstream of the exhaust and upstream of the blower.
Figure 4. Cambridge filter and holder. If we have access to a vacuum pump from team 10056 or the Bio-lab from Dr. Robinson, we could set up a pump and filter system. We can run experimental data to calculate headloss KGCOE MSD Page 24 of 31 Technical Review
through the filter as well and compare with data collected last year to determine the necessary flow rate to sample exhaust flow from the main exhaust.
Placement of Sampling System According to a Water Boil Test publication, sampling should be down atleast 8 duct diameters downstream of the start of ducting and 2 duct diameters upstream of the blower. However to integrate this system into our test stand, experiments will have to be conducted to find an optimal location.
Advantages Provide a breakdown of particulate matter emitted during different stages of combustion. Capture smaller diameter particles. More accurate than previous proposed method. Can have samples sent to NTID lab and have chemical composition of particles collected analyzed for better data. Disadvantages No real time results. More expensive than previous method since moving parts are involved. Setting up a system to easily remove filters for multiple samples during one test. Dealing with humidity and heat – can damage or skew measurements. Can be difficult to implement.
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Proposed Sampling System By integrating features from both concepts and modifying team 10056’s design, this is a proposed particulate matter sampling system.
Cyclone
Filter & Holder
Impinger
Blower
Vacuum Pump
Cyclone (Or Expansion) By having a cyclone or some kind of expansion be first in the sampling system, we can separate larger diameter particles from the exhaust and also separate liquid vapor from reaching the filter.
Figure 5. Cyclone example
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Filter & Holder By using the Cambridge filter and holder system from 10056, we can catch smaller diameter particles. Dr. Robinson’s lab has a scale to tare the filters and measure the particles collected after testing.
Impinger
Also integrating the use of an impinger filled with methanol such as the use in team 10056’s system, we can collect any remaining gaseous particulate matter that may have passed through the filter. This will not only help serve as a visual aid and comparison of particulate matter but would also help protect the vacuum pump.
Vacuum Pump
Find an acceptable vacuum pump for our system and account for losses through the system. Perhaps borrow a pump from Dr. Robinson for initial experimental testing and then purchase a permanent pump for the system.
Conclusion
This system would provide a quantitative comparison between stoves tested within our test stand. Using any leftover equipment from team 10056 and their bill of materials, obtaining parts for this system will not be challenging. Filters can also be sent to NTID lab for a chemical analysis. System design is a work in progress as experimental testing to see if the system is feasible is required.
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Preliminary Test Plan
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Process Flow Chart
START
What Kind of Test?
Only Cold Start Modified WBT
Measure Starting Full WBT Liquid and Charcoal Measure Starting Measure Starting Liquid and Liquid and Charcoal Charcoal
Standardize Is it standard NO amount of SL and amount? Charcoal to Standardize Is it standard amount of SL and Is it standard minimize variation NO NO amount? Charcoal to amount? YES minimize variation
YES YES Measure Initial Stove Conditions Measure Initial Stove Conditions Measure Initial Stove Conditions
Proceed in starting fire Put Pot with 2.5 L Proceed in starting fire Water on Fire Put Pot with 5 L Water Proceed in starting fire on Fire Put Pot with 2.5 L Water on Fire
Record CO, Temperature Record CO, Temperature every 10 seconds, every 10 seconds Weight Values every Record CO, Temperature Weight Values every minute every 10 seconds minute Weight Values every minute When the water When the water reaches boiling reaches boiling temperature, record the When the water reaches temperature, record the time to boil and boiling temperature, time to boil and measure final record the time to boil measure intermediate conditions and measure conditions intermediate conditions
INITIAL STOVE CONDITIONS: INTERMEDIATE CONDITIONS: Proceed in and Start to WEIGHTS(KG) OF WEIGHTS OF Hot Start by dumping out Proceed in and Start to Pot+Water Base+Fuel the used charcoal and Simmer for 20 minutes Pot Pot+Water adding new charcoal to Continue to record values Fuel Base+Fuel+Pot+Water hot stove every minute. Starting Liquid+Cup Base Base+Fuel FINAL CONDITIONS: When the water reaches Base+Fuel+SL WEIGHTS OF to the boiling temperature Base+Fuel+SL+Pot+Water Base+Fuel with hot start, Record the TEMPERATURE (C) OF Pot+Water time to boil. Measure Final Conditions AMBIENT Base+Fuel+Pot+Water when simmering is over WATER Start to simmer for 45 mins Continue to record values
Measure Final Conditions when simmering is over
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Issues
# Noise Factor Possible Cause Test Run? (y/n) Result Collapse of charcoal pile due to Use Stovetek Stove without water and 1 CO data spikes at random intervals burning could cause a spike in stir the charcoal to artificially enduce a No N/A emmisions collapse of charcoal. Boil water and take many data points at There is a variation in water Water temperature doesn’t reach Localized boiling or not a well mixed other points besides the center to 2 Yes temperature. However it is only 100 degrees celcius liquid. determine if the center is a an average of ~1.2°C -Negligible representative temperature. Water temperature doesn’t reach Thermocouple is losing heat before Add insulation to themocouple and Water temperature will reach 3 Yes 100 degrees celcius signal can be read. perform WBT. 100 degrees with insulation. Rocket stove needs to have additional Add another .177kg of charcoal to the Water temperature doesn’t reach charcoal added to it because the fire 4 stove after fire dies down. (This brings No N/A 100 degrees celcius dies down before a boil can be total coal used to .5kg) reached. Perform typical Modified WBT as before Steady state conditions in the test without opening the test stand. This is 5 Water heats up at different rates stand are interupted with regular possible with new logging software and No N/A opening of the test stand thermocouple-the data will record itself without human interaction. Perform typical WBT noting the distance Placement of charcoal, or how far the of the charcoal pile from the pot. If this 6 Water heats up at different rates No N/A fire is from the pot to start. value is noisy, then attempt to standardize.
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Temperature Variation (Test #2 Results) Water Temp vs Time 120 Probe Cor Middle Probe 100
80
60
WaterTemp (C) 40
20
0 18:28:48 18:36:00 18:43:12 18:50:24 18:57:36 19:04:48 19:12:00 Time One test was run on the StoveTec Stove to confirm or deny the assumption that the center probe was a good measurement of temperature throughout the pot. This test was conducted by moving the thermal couple around in the pot away from the center at a sampling at 1Hz. Based on this data we can see that our assumption of uniform temperature is reasonable and do not need to gather an array of temperatures through the pot.
Test #3 Results Water Temp vs Time
120
100
80
60 H20 Temp (C) 1
40 Temperature(C)
20
0 0 5 10 15 20 25 30 35 40 Time (min)
From the latest test on the Rebar Haitian Cook stove, the temperature in the water does reach a full 100 degrees now that the insulation has been added to the thermocouple.
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