Crispin: Could you comment on the several items I am unclear about from your message today.
1. Is the lab pretty much going to be reserved for coal-burning stoves? 2. I gather that particulate emission is particularly bad with coal in UB - or is it just as bad from most wood burning stoves in other parts of the world? 3. Re this sentence: "The total range of the particulate concentration from a bad stove during ignition to a good stove during flaming pyrolysis is 10,000:1. " a. Do you feel this is true of wood burning stoves as well? b. Would this statistic apply to recharging a relatively hot stove with glowing embers? c. Is your statement about 98% relief related to a conversion to BLDD (Bottom Lit Down Draft) d. In your down draft stove development, are you always bottom lit? e. Do you think your DD work has application to wood burning stoves? f. Does "flaming pyrolysis" imply testing of both DD and UD (with appropriate BL and TL modifiers?) 4. Can the new test lab accommodate chimneys of several story height? 5. The standard (?) heating stove in many nordic and slavic countries has a single ignition each day with the chimney having a long tortuous path to the roof - in order to capture and store the energy. Would that work in UB? 6. Is there a role for more energy efficiency (bigger wall/ceiling R-values) and solar space heating (both active and passive)? 7. You cite 400,000 ignitions per day. What is the total number of stoves in UB? What is the relationship between space-heating and cooking? Same stove? Started sometimes for cooking only? 8. There is mention of different fuels. What are being considered? Ron ----- Original Message ----- From: "Crispin Pemberton-Pigott" <[email protected]> To: "Discussion of biomass cooking stoves" <[email protected]> Sent: Sunday, August 1, 2010 7:07:02 AM Subject: Re: [Stoves] Stove Testing Lab in UB !! Dear Sarath I am sharing my answer with the group because it will save time and share information that may be helpful to others. The laboratory in Ulaanbaatar is being built by the Asian Development Bank for the purpose of offering stove testing services to local developers and manufacturers. It is part of a World Bank managed multi-sector clean air plan for the City of Ulaanbaatar. The purpose of the lab is the be able to rate the performance of domestic stoves, to measure particulate emissions and thermal performance for space heating and cooking. Multiple fuel+stove combinations will be measured including varying the operator techniques. It will measure condensed particulates using a fairly simple method (compared with EPA 5G) and is constructed in such a way as to avoid counting condensed water droplets as 'particles' (which technically they are but we don't worry about them). If you take the emissions from a stove and count the particles, light scattering equipment counts water droplets as if they are carbon or other particles because they scatter light very well. The system we are building avoids this by diluting the sample with dry air to reduce the dew point to less than 10 degrees C. The particles are then counted and reported as PM1, 2.5, 4 and 10 in real time. They are also collected on filters so we can check that the counter is working properly. Thermal efficiency is straightforward: we will use the Siegert formula to determine the space heating efficiency. The traditional stove burning raw coal is pretty good. The 'gain' available is to reduce the particulate emissions that make the city so unliveable. The thermal efficiency can be raise perhaps 10 to 15% with a good stove. I believe we can reduce the smoke produced by 98%. It is important for our purposes that tests can continue uninterrupted for as long as 8 hours because that is the overnight fuelling cycle. This means creating a gas sample drying system so nothing gets wet. This has been accomplished using Nafion dryers. We pass the gas through a central tube at low pressure (3 PSI) and have a vacuum in an enclosing outer tube. Moisture passes through the wall of the hydrophilic inner tube and is swept away by air. We have three such dryers in the system. Air Dimension in Florida helped define the parameters of the vacuum/pressure pumps to achieve this. The gas emerges with a dew point well below O degrees C. Further, the gas samples are measured on heated devices (50 C) at a constant positive pressure (3 PSI) to eliminate variation in the accuracy. The particles are counted in a diluted gas stream. The amount of dilution is check in real time by monitoring the CO2 level in both the stack and the particle stream. This was originally suggested by Dr Tami Bond. The gas analyser has been constructed with this in mind: two CO2 channels of different concentrations, CO and O2. Later we will add SO2, NO, H2S and H2. The diluter was designed by yours truly and is still to be tested so it is quite 'adjustable'. We are aiming for a dilution from 1:10 up to 1:100. Because of the way the data logging system has been designed, we can change the dilution any time we want to keep the particle counter in range. The total range of the particulate concentration from a bad stove during ignition to a good stove during flaming pyrolysis is 10,000:1. No counter can deal with this so the diluter can be varied (a lot). For the moment we are going to concentrate on measuring the emissions during the ignition cycle as that has been found to create the vast majority of smoke that will emerge during the burn. Tami reported this years ago during her trip to Honduras. Work by Prof Seteeter Lodoysamba at the Nuclear Research Laboratory at the National University of Mongolia has proven this to be true on a city-wide scale in Ulaanbaatar. Air quality is not particularly related to the quantity of coal burned, but to the number of times the stoves are ignited. The worst days are in November with perhaps 400,000 ignitions per day. In February the quantity of coal burned is double, the inversions are more severe (trapping smoke in the valley) but the pollution is half. Why? The stoves are kept burning because it is so much colder! The number of ignitions is dramatically reduced. All very interesting, neh? There is a great deal of research needed to be done during the coming 2 years. It will include the development of new products with dramatically reduce emissions, especially during ignition. Many new fuels are expected to be tried as well as innovative operating procedures. Regards Crispin +++++++++++ From: Sarath Guttikunda .Just out of curious about the testing lab you are setting up in UB. Can you send some more details? What tests are being conducted? Which stoves? etc. _______________________________________________ Stoves mailing list [email protected] http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org http://stoves.bioenergylists.org http://info.bioenergylists.org
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