Characterization of Plancha Stove Performance in Rural Guatemala

Transcription

1 Characterization of Plancha Stove Performance in Rural Guatemala Devin Udesen, Garrett Allawatt, John Kramlich, Jonathan Posner University of Washington Clean Cookstoves Lab (UWCCL), Seattle, WA Joe Gilmour, Brian Gylland, Paul Means BURN Design Lab (BDL), Vashon, WA Marco Maldonado Hands for Peacemaking Foundation (HFPF), Everett, WA ETHOS 28 th January 218 1

2 Project Overview Goals: Develop a new lab testing procedure that better reflects stove usage in the field. Develop an understanding of Plancha stove-design, emissions, efficiency, and usage. Improve upon existing Aler-stove with a Plancha-design that, reduces emissions, increases efficiency, decreases manufacturing costs, and meets the usage needs of our target community. Contributors: Research/Testing/Design UWCCL and BDL Manufacturing/Field-Research HFPF 2

3 Target Community Location: Barillas, Guatemala + surrounding villages Current-Market Need: 1, stoves Expanded-Market Need: 5, stoves Total-Market Need in Guatemala: 2.4 million stoves 3

4 Aler-Stove 4

5 Field Survey Surveyed households in villages surrounding Barillas that are currently using the Aler-Stove. # of Stoves in use: 3 Survey included: Household/stove-usage questionnaire Observation of cooking event Note: Exhaust Temperature was measured using a type-k thermocouple with a 1 min resolution in the center of the stack, 1cm above the lower stack-elbow. 5

6 Household Stove-Usage # of Households Surveyed 8 Family Size 5-7 persons Stove Use Per Day 5-7 hrs Cooking Technique 1% used a mixture of pots, pans, and direct stove-top cooking Stove Used for Heating 75% use stove as a household heat source (seasonal) Stove Used in Between Meals 1% don t add wood to the stove between meals Cooking Task Tortillas, Tamales, Boiling Beans/Corn/Potatoes, Coffee, Boiling Water 6

7 Fuel Characteristics Source of Wood 1% gather wood (do not purchase) Wood Storage Technique 1% use covered wood storage Stove Used to Dry Wood 88% use latent heat to dry wood Fire-Starter Used 1% use mixture of cornhusks and ocote-kindling 6 Average Fuel Size (Hyd. Dia.) 3 ±.5 cm Average Fuel Moisture Content 31 ± 8 %, Dry Basis Fuel Moisture (%, dry basis) Field Lab Hydraulic Diameter (cm) 7

8 Cooking Event Observation Meal Cooked Boiled 15lbs of corn and a pot of coffee # of People Cooking for 7 Duration / Time of Day 71 min / 1: AM # of Sticks / Size / Moisture Content 5 / 3 cm (hydraulic-diameter) / 21% (dry-basis) Tending Time 12 min Exhaust Temp. (Deg. C) Exhaust-Temperature Time (min) 8

9 Impact of Firepower on Emissions PM (mg/min) Tier 1 2 Tier 2 Tier 3 Tier Fire-Power (kw) 9

10 Impact of Firepower on Emissions PM (mg/min) 8 6 Field Firepower Range?!? 4 Tier 1 2 Tier 2 Tier 3 Tier Fire-Power (kw) 1

11 Impact of Firepower on Emissions PM (mg/min) 8 6 Field Firepower Range?!? 4 Tier 1 2 Tier 2 LP HP Tier 3 Tier Fire-Power (kw) 11

12 Impact of Firepower on Emissions PM (mg/min) 8 6 Field Firepower Range?!? 4 Tier 1 2 Tier 2 LP LP LP LP HP HP HP HP Tier 3 Tier Fire-Power (kw) 12

13 Impact of Firepower on Emissions PM (mg/min) = 4 HP/LP = 3 test s per = 2 hours per test = 24 hours of testing We can do this in 1 test = 3 hours Field Firepower Range?!? 4 Tier 1 2 Tier 2 LP LP LP LP HP HP HP HP Tier 3 Tier Fire-Power (kw) 13

14 What we know: Stove operation can vary significantly in the field. Stove operation impacts performance. What we need to know: How the stove is operated/used in the field. Emissions and efficiency in the field. Difficult to determine without extensive field research Potential Solution: Use exhaust-temperature to determine the distribution and range of firepower s expected during a typical day in the field. Replicate stove usage in the lab based off of field-firepower distribution. Improved prediction of performance in the field. Stove design that meets performance goals in the field (NOT just the lab). 14

15 Lab Measurements 15

16 Lab Testing Test Procedure: Firepower-sweep Operate stove continuously throughout a wide-range of firepower s. Use CO2 as indicator of firepower. Correlate exhaust temperature to firepower. Collect behavior-data of emissions, thermal-efficiency, combustion-efficiency, component temperatures, etc. Normalized CO2 (PPM) PM (mg/min) Time (sec) Fire-Power (kw) 16

17 Lab CO2-Concentration Normalized CO2 (PPM) Time (sec) 17

18 Firepower from CO Normalized CO2 (PPM) Firepower (kw) Time (sec) Burn-Rate = f(co2, C-ratio,Sample-Dilution, Time) Firepower = f(burn-rate, Heating-Value, Time) 18

19 Firepower and Exhaust-Temperature 8 18 Exhaust Temp. (Deg. C) Fire-Power (kw) Time (sec) 19

20 Correlation Between Firepower and Exhaust- Temperature 8 7 Exhaust Temp. (Deg. C) R² = Fire-Power (kw) 2

21 Field Exhaust-Temperature Exhaust Temp. (Deg. C) Time (min) 21

22 Field-Firepower from Field Exhaust-Temperature Exhaust Temp. (Deg. C) Firepower (kw) Time (min) 22

23 Field-Firepower Distribution 23

24 Field PM Analysis 24

25 Full Performance Behavior Each stove design and unique cooking tasks: Particulate-Emissions CO2 and CO Thermal-Efficiency Combustion-Efficiency Component-Temperatures 1. Predict daily performance using firepower distribution and performance behavior. 2. Informed design decisions. 3. Understand impact of design alterations. 25

26 Current Investigations Exhaust-Temperature/Stove-Performance Model Development: What are the impacts of Wood size and fuel moisture. Ambient temperature and humidity. Stove deterioration. Cooking technique (pot, stove-top, open stove-top, etc.). Cyclic behavior (HP LP, LP HP, etc.). Plancha Efficiency: Burner AND stove-top efficiency. Field Survey Improvements: Daily temperature data for each household. More specifics about cooking habits/techniques/wants/needs Increase sample size!!! 26

27 Questions? 27