In this article,we evaluated the energy performance parameters and gas emissions to identify which of the stoves studied performs best,and the biomass char briquettes with less emission.Biomass char briquettes from pe...In this article,we evaluated the energy performance parameters and gas emissions to identify which of the stoves studied performs best,and the biomass char briquettes with less emission.Biomass char briquettes from peanut shells,cashew nut shells,and corn cobs were produced using wheat flour as a binder.The binder rate was set at 9%and 10%.Based on the energy performance parameters,it was highlighted that the char briquette from corn cob with 9%binder(Char_CC_9%)has the best energy performance,followed by the char briquette from peanut shells with 9%binder(Char_PNS_9%),and lastly,the char briquette from cashew nut shells with 10%binder(Char_CNS_10%).The average energy efficiency of the“jambar”stove was 15.68%,while that of the“Malgache”stove was 12.41%.The average specific fuel consumption of the“jambar”stove was 0.12 kg of fuel per kilogram of water while that of the“Malgache”stove was 0.15 kg of fuel per kilogram of water.In terms of gaseous emissions,CO(carbon monoxide)concentrations were very high for char briquettes from corn cobs,with a CO emission factor of 0.40 g/min and NOx emission factor of 9.79 mg/min.For char briquettes from cashew nut shells,CO and NOx emission factors were respectively 0.30 g/min and 5.32 mg/min.The lowest average concentrations were obtained with char briquettes from peanut shells with a CO emission factor of 0.25 g/min and NO_(x) 3.98 mg/min.展开更多
Household air pollution is considered to be among the top environmental risks in China.To examine the performance of improved stoves for reduction of indoor particulate matter（PM） emission and exposure in rural hous...Household air pollution is considered to be among the top environmental risks in China.To examine the performance of improved stoves for reduction of indoor particulate matter（PM） emission and exposure in rural households, individual inhalation exposure to size-resolved PM was investigated using personal portable samplers carried by residents using wood gasifier stoves or improved coal stoves in a rural county in Central China.Concentrations of PM with different sizes in stationary indoor and outdoor air were also monitored at paired sites. The stationary concentrations of size-resolved PM in indoor air were greater than those in outdoor air, especially finer particles PM0.25. The daily averaged exposure concentrations of PM0.25, PM1.0, PM2.5 and total suspended particle for all the surveyed residents were 74.4 ± 41.1, 159.3 ± 74.3, 176.7 ± 78.1 and 217.9 ± 78.1 μg/m3,respectively. Even using the improved stoves, the individual exposure to indoor PM far exceeded the air quality guideline by WHO at 25 μg/m3. Submicron particles PM1.0 were the dominant PM fraction for personal exposure and indoor and outdoor air. Personal exposure exhibited a closer correlation with indoor PM concentrations than that for outdoor concentrations. Both inhalation exposure and indoor air PM concentrations in the rural households with gasifier firewood stoves were evidently lower than the reported results using traditional firewood stoves. However, local governments in the studied rural areas should exercise caution when widely and hastily promoting gasifier firewood stoves in place of improved coal stoves, due to the higher PM levels in indoor and outdoor air and personal inhaled exposure.展开更多
Exposure to high PM10 by women and children for hours on a daily basis in poor ventilated kitchen may lead to respiratory morbidity among this vulnerable group. In Nigeria, data on the levels of air pollutants associa...Exposure to high PM10 by women and children for hours on a daily basis in poor ventilated kitchen may lead to respiratory morbidity among this vulnerable group. In Nigeria, data on the levels of air pollutants associated with kerosene stove combustion are very scarce. Like-wise little had been documented on the pulmonary health of women exposed to kerosene stove emission. This study was carried out to measure the levels of kerosene combustion emissions within kitchen environments and also assess the pulmonary function status of the exposed women at baseline. Particulate matter (PM10) and gaseous emissions (GE) were measured in six purposively selected clusters of regular kerosene stove users (KSU) using gravimetric sampler and gas monitors, respectively and their values compared with WHO guideline limits. 167 randomly selected KSU were surveyed to elicit their socio demographic features. A spirometer was used to assess the lung function status (FEV1) of 72 KSU in six neighbourhood kitchen clusters. Data were analysed using descriptive statistics, and Pearson’s correlation tests. Respondents’ mean age was 38 + 12.9 years. Mean duration of exposure to GE was 18.9 + 9.8 years. Mean PM10 was 248.1 + 14.1 μg/m3 and ten folds higher than WHO guideline limit of 25 μg/m3. Mean GE in ppm were: CO (0.00), CO2 (200.1 + 12.4), SO2 (0.01 + 0.00) and NO2 (0.00). Mean FEV1 among KSU was 2.0 + 0.5 litres which was significantly lower than the mean predicted value of 2.7 ± 0.5 litres. There was a negative correlation between PM10 and FEV1 (r = -0.7539, p > 0.05). Safer cooking methods and practices to obviate health hazards are advocated.展开更多
It is estimated that more than 2.5 billion people worldwide use biomass for cooking. Burning biomass is one of the major contributors to carbon dioxide (CO2) emission—a principle gas in global warming and climate cha...It is estimated that more than 2.5 billion people worldwide use biomass for cooking. Burning biomass is one of the major contributors to carbon dioxide (CO2) emission—a principle gas in global warming and climate change. One way of cutting down the CO2 emissions is adaptation of efficient and clean energy technologies. This study examined the efficiency of the energy saving stoves in Amboseli ecosystem by comparing the cooking time, energy use, wood fuel and carbon emissions to the traditional three stone open fire set ups. The result indicates a statistical difference in the time spent cooking on energy stoves and three stone open fire (t = 5.3055;n = 60;p = 0.00117). Energy saving stoves saved 12.7% - 33.3% of wood fuel compared to the traditional three stones set ups. Water boiling tests to determine the energy savings, revealed that energy saving stoves saved between 25.74% and 26.16% energy/joule per session in-house and outdoor settings respectively. Based on the two meals prepared per day by each household, the total Carbon Emission Savings for the 1000 local beneficiaries of energy saving stoves varied from 102,200 kg CO2 (indoor cooking) to 357,700 kg CO2 (outdoor cooking) per year. It is therefore concluded that energy saving stoves saves time, fuel wood and energy, and reduces carbon emissions. The study findings refute the claims that open fire when carefully operated can be fuel efficient and clean burning to rival energy saving stoves. To improve the performance of the energy saving stoves, it is recommended that a design modification be done to include a chimney to emit excess smoke during indoor cooking;and the stove should be fixed to the floor with mortar to minimise heat loss and breakages.展开更多
An earthen kitchen stove caught my attention on a recent visit to the Tibet Museum, as such a stove, commonly used by the Tibetans only a dozen years ago, can hardly be found today in the region.Varieties of StovesTib...An earthen kitchen stove caught my attention on a recent visit to the Tibet Museum, as such a stove, commonly used by the Tibetans only a dozen years ago, can hardly be found today in the region.Varieties of StovesTibetans used a variety of stoves in the past. For instance, they used rectangular stoves with several pots, and oval stoves to press edible oil. Monastery monks adopted types that were sometimes as large as a small room. Ordinary Tibetans had the following four kinds of stoves for cooking:展开更多
Straw pellets are widely promoted and expected to be a cleaner alternative fuel to unprocessed crop residues and rawcoal in rural China.However,the effectiveness of these dissemination programs is not well evaluated.I...Straw pellets are widely promoted and expected to be a cleaner alternative fuel to unprocessed crop residues and rawcoal in rural China.However,the effectiveness of these dissemination programs is not well evaluated.In this field study,emission characteristics of burning strawpellets,rawcoal,and unprocessed corn cobs in heating stoveswere investigated in a pilot village in Northeast China.Emission measurements covering the whole combustion cycle(ignition,flaming,and smoldering phases)shows the promotion of improved heating stoves and straw pellets could reduce pollutant emissions(e.g.,SO_(2) and CO),but increase NO_(X) and PM_(2.5) emissions compared to the initial stove-fuel use pattern in the studied area.There is a significant variance in emission characteristics between different combustion phases.The normalized emission concentrations of the different stove-fuel combinations were higher than the limits in the Chinese national standard for heating stoves,indicating that the standard is not met for real-world emissions.Coal consumption was lower than official data.Household surveys were conducted to identify the barriers to fuel and stove access associated with existing promotion strategies,management,and policies.The pilot program was of the typical“subsidy-and-policy-dependence”pattern and was unlikely to be implemented on a large scale.Technological innovation,operational optimization,and proper policies considering the local socioeconomic factors are needed to sustain the promotion of biomass straw pellets and stoves.展开更多
Biochar is a solid material obtained from the carbonization of biomass. Biochar is used on agricultural lands as a soil amendment to improve the fertility of the soils. Currently the most common method of producing bi...Biochar is a solid material obtained from the carbonization of biomass. Biochar is used on agricultural lands as a soil amendment to improve the fertility of the soils. Currently the most common method of producing biochar is through biochar stoves. There are two basic stove operations in the production of biochar. The first type of stove produces biochar by direct combustion of biomass. Here biomass is burnt inside a chamber in an oxygen limited environment. The resulting residue is the bio-char. The second type involves burning the biomass in one chamber and housing the biomass to be charred in the annular portion of an outer chamber. Heat is transferred from the burning fuel on the inner chamber to the material to be charred in the outer chamber. While the process of biochar production in these stoves is known, the basic principles of the stove design are not readily available. The design methodology for both the types was developed from first principles. Prototypes of both types were constructed based on the design developed and tested. The paper lists the basic principles in the design of biochar stoves and the test results.展开更多
The Design of Experiments (DOE) and the Analysis of Variance (ANOVA) are used to determine the effect of fuel type, fuel initial load, secondary air inlet and ventilation on thermal efficiency and CO emission of two b...The Design of Experiments (DOE) and the Analysis of Variance (ANOVA) are used to determine the effect of fuel type, fuel initial load, secondary air inlet and ventilation on thermal efficiency and CO emission of two biomass fire cookstoves during boiling or simmering. Analysis of variance with Fischer’s statistical test (F-test) and Newman-Keuls test were applied to establish the influence of the independent parameters on the studied responses. The results of this study are useful to application of charcoal cooks stoves.展开更多
The extensive use of traditional cooking and heating stoves to meet domestic requirements creates a serious problem of indoor and outdoor air pollution.This study reports the impacts of two fuel feeding methods-front-...The extensive use of traditional cooking and heating stoves to meet domestic requirements creates a serious problem of indoor and outdoor air pollution.This study reports the impacts of two fuel feeding methods-front-loading and top-loading on the thermal and emissions performance of a modern coal-fired water-heating and cooking stove using a contextual test sequence that replicates typical patterns of domestic use.Known as a low-pressure boiler,when this stove was fueled with raw coal,the findings indicate that front-loading the fuel,which devolatilizes the new fuel gradually,produced consistently higher space heating efficiency and lower emission factors than top-loading the same stove,which devolatilizes new fuel all at once.Comparing the performance at both high and low power gave the similar results:front-loading with raw coal produced consistently better results than top-loading.The average water heating efficiency when front-loading was(58.6±2.3)%and(53.4±1.8)%for top-loading.Over the sixteen-hour test sequence,front-loading produced 22%lower emissions of PM2.5(3.9±0.6)mg/MJNET than top-loading(4.7±0.9)mg/MJNET.The same pattern was observed for carbon monoxide and the CO/CO2 ratio.CO was reduced from(5.0±0.4)g/MJNET to(4.1±0.5)g/MJNET.The combustion efficiency(CO/CO2 ratio)improved from(8.2±0.8)%to(6.6±0.6)%.Briquetted semi-coked coal briquettes are promoted as a raw coal substitute,and the tests were replicated using this fuel.Again,the same pattern of improved performance was observed.Front loading produced 3.5%higher heating efficiency,10%lower CO and a 0.9%lower CO/CO2 ratio.It is concluded that,compared with top loading,the manufacturers recommended front-loading refueling behavior delivered better thermal,emissions and combustion performance under all test conditions with those two fuels.展开更多
Last Sunday,I felt very hungry when I got up late.There was no food in the fridge,so l decided to cook noodles for me①.First,I filled the pot with water and put it on the stove.I waited patiently for the water to boi...Last Sunday,I felt very hungry when I got up late.There was no food in the fridge,so l decided to cook noodles for me①.First,I filled the pot with water and put it on the stove.I waited patiently for the water to boil.Then,I put the noodles into the boiling water.Next,I added some vegetables,an egg,and a little salt.展开更多
This study systematically investigated the effects of different gas stove structures on flame combustion characteristics using spectral diagnostic techniques,aiming to provide optimized design guidelines for clean ene...This study systematically investigated the effects of different gas stove structures on flame combustion characteristics using spectral diagnostic techniques,aiming to provide optimized design guidelines for clean energy applications.To explore the combustion behaviors of various gas stove structures,UV cameras,high-speed cameras,and K-type thermocouples were employed to measure parameters such as flame OH radicals(OH*),flame morphology,pulsation frequency,flame temperature,and heat flux.The results demonstrate that flame stability was achieved at an inner/outer cover flow rate ratio of 0.5/4.0 L/min,beyond which further flow rate increases led to reduced combustion efficiency.Compared to covered stoves,top-uncovered stove exhibited 5.5%and 12.4%higher temperatures at the inner and outer covers,respectively,along with a 35%increase in heat flux.Comprehensive analysis revealed an approximately 20%enhancement in overall flame intensity.The experimental results show that top-uncovered gas stoves exhibit higher flame intensity,greater combustion efficiency,and overall higher stove efficiency.In contrast,covered gas stoves feature a more controllable and stable flame with a gentler temperature rise.This study underscores the importance of optimizing gas stove designs to enhance combustion efficiency and reduce emissions,contributing to the transition from fossil fuels to renewable energy sources and promoting sustainable development.展开更多
The main function of a hot blast stove is to deliver a high-temperature and stable hot blast to the blast furnace,which has an important impact on the blast furnace ironmaking process.To improve the combustion efficie...The main function of a hot blast stove is to deliver a high-temperature and stable hot blast to the blast furnace,which has an important impact on the blast furnace ironmaking process.To improve the combustion efficiency,a simulation model of the combustion part of an internal combustion hot blast stove was established by combining turbulence,combustion,and radiation models.Based on the original model,a new type of internal combustion hot blast stove is proposed.The results indicated insufficient combustion in the original structure and higher CO concentrations in the corners of the eyes at both ends of the combustor outlet,the recirculation area at the bottom of the combustion chamber was mainly concentrated in the middle part.With the new structure of the hot blast stove,the gas baffles with different inclination angles are added to the rectangular burner,at the outlet of the combustion chamber,the CO concentration is reduced to a certain extent,and the temperature distribution is more uniform.When the inclination angle of the gas baffle is 60°,the combustion chamber outlet section average temperature rises from 1686 K to 1693 K,the outlet flue gas average volume fraction of CO decreases the most,and the average volume fraction of CO decreases from 0.00708%to 0.00568%,which could reduce the CO content by about 20%.展开更多
Charcoal stove is widely used in the developing countries especially in Africa and Central America.Even reported to have a high impact on human health,stoves promoted in the related areas still mainly focus on fuel sa...Charcoal stove is widely used in the developing countries especially in Africa and Central America.Even reported to have a high impact on human health,stoves promoted in the related areas still mainly focus on fuel saving and little knowledge was reported for the stove performance in the field.This research evaluated four commercialized charcoal stoves with clay baseline stove using a modified Chinese cooking stove protocol that considered the local cooking habit to make the testing results more useful for the local stove promotion.The results showed that the thermal efficiency of tested charcoal stoves ranged from 38.7%to 47.5%,and the cooking power was around 640-1200 W.The CO emission factors of the improved stove had a 60%reduction compared with baseline stove.Different indicators reporting the same aspect of the stove were evaluated,and it suggested choosing the indicators according to the project requirements.展开更多
The sustainable land management (SLM) project is seeking to engage with public institutions to explore the possibility of using the energy-switch principle presented by the carbon market to reduce emissions from ineff...The sustainable land management (SLM) project is seeking to engage with public institutions to explore the possibility of using the energy-switch principle presented by the carbon market to reduce emissions from inefficient use of biomass energy and discharge of human waste into the environment. Such a switch will be a triple-win situation that improves the natural environment, reduces deforestation, and provides avenues for revenue generation. As such, it commissioned a study of the pattern of energy consumption in the institutions and the type of cooking stoves they employ. Results show that firewood (51%) is the most widely used fuel because of availability, affordability, and reliability. The study also found that 56% of the institutions use energy-saving stoves, which is an opportunity that the project can seize to encourage use of alternatives sources of energy as opposed to biomass. In addition, 88% of the institutions expressed willingness to switch to biogas for cooking. This is yet another opportunity for scaling up the dissemination of renewable sources of energy in the region. Better adoption and wider use of renewable energy sources will take place when innovative financing mechanisms are devised to cover the high upfront cost of installing renewable energy systems. This has been one of the main barriers to scaling up the use of renewable in the region.展开更多
Many communities across the globe still practice poor cooking cultures as part of their well-being to prepare food and other heating activities. Such bad cooking practices are not environmentally friendly, are wastefu...Many communities across the globe still practice poor cooking cultures as part of their well-being to prepare food and other heating activities. Such bad cooking practices are not environmentally friendly, are wasteful </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> have adverse health effects. This work presents the results of the survey that was conducted to establish the existing cooking practices commonly used in Uganda, identify the commonly used fuel during cooking, identify perceptions on improved cooking stoves (ICS), perceived preferences during cooking as well as identify whether users are aware of the health challenges due to poor cooking and describe community opinions of ICS for rural communities in Uganda. The interviews were conducted on household levels across all the regions covering Uganda’s major rural regions. It was observed that </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">largest</span><span style="font-family:""><span style="font-family:Verdana;"> population of rural Ugandans still use the 3 stone stove fire for cooking with a percentage of 53.5%, Charcoal stove, 27.3%, Improved cooking stove, 16.9%, Electric cookers,1.2%, LPG 0.7% </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> biogas 0.5% for the preparation of their various types of cooked foods while forest firewood is the commonly used biomass fuel for cooking with a percentage of 66.8% compared to Charcoal, Briquettes, </span><span style="font-family:Verdana;">Saw dust</span><span style="font-family:Verdana;"> and others with a percentage of 27.1%, 0.7%, 0.7%, 1.1% respectively. This reveals the great majority of users whose life is at risk as 3 stone stoves are characterized by low efficiency and high smoke production which increases the health risks of the users as well as increase the risk of deforestation rates. Household cooks showed great willingness to pay for a novel stove type in all </span><span style="font-family:Verdana;">the 4</span><span style="font-family:Verdana;"> regions but from the survey data, it was indicated that the preferences varied from one region to another with a great majority preferring minimal smoke production with increased heat retention capacity. It was revealed that 91.4% of the interviewed households were aware of the health challenges due to poor cooking methods which they resolve</span></span><span style="font-family:Verdana;">d</span><span style="font-family:""><span style="font-family:Verdana;"> by using open space during cooking. There was variation in the quantity of food cooked in a day, time spent on cooking </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> how often the cooking is done from one region to another due to the difference in economic activities as well as the different climate factors. While using cooking stoves, users preferred large cooking pot space with minimal smoke production and rapid heating. Such information can act as a basis for the design of an improved cooking stove for the rural Ugandan community as engineered products must be designed to suit the needs of the end-user.展开更多
In Shougang Jingtang 5 500m 3 huge blast furnace ( BF ) design , dome combustion hot blast stove ( DCHBS ) technology is developed.DCHBS process is optimized and integrated , and reasonable hot blast stove ( HBS ) tec...In Shougang Jingtang 5 500m 3 huge blast furnace ( BF ) design , dome combustion hot blast stove ( DCHBS ) technology is developed.DCHBS process is optimized and integrated , and reasonable hot blast stove ( HBS ) technical parameters are determined.Mathematic model is established and adopted by computational fluid dynamics ( CFD ) .The transmission theory is studied for hot blast stove combustion and gas flow , and distribution results of HBS velocity field , CO density field and temperature field are achieved.Physical test model and hot trail unit are established , and the numeral calculation result is verified through test and investigation.3-D simulation design is adopted.HBS process flow and process layout are optimized and designed.Combustion air two-stage high temperature preheating technology is designed and developed.Two sets of small size DCHBSs are adopted to preheat the combustion air to 520-600℃.With the precondition of BF gas combustion , the hot blast stove dome temperature can exceed 1 420 ℃. According to DCHBS technical features , reasonable refractory structure is designed.Effective technical measures are adopted to prevent hot blast stove shell intercrystalline stress corrosion.Hot blast stove hot pipe and lining system are optimized and designed.After blowing in , the blast temperature keeps increasing , and the monthly average blast temperature reaches 1 300℃ when burning single BF gas.展开更多
Hazard control of NOx is very important for the long life of hot stove shell and environmental protection. NOx concentrations during different operation periods of hot stove were calculated according to thermodynamica...Hazard control of NOx is very important for the long life of hot stove shell and environmental protection. NOx concentrations during different operation periods of hot stove were calculated according to thermodynamical and dynamical analyses. The results were verified by the previously measured data. Then, the influence of hot stove oper- ation parameters on NOx concentration and the mechanism of liquid water formation in hot stove were studied. The results indicated that in gas period, the dome temperature should be controlled below 1420 ℃ in order to decrease NO~ emission. In the case of banking operation, NOx concentration was about 40--60 times higher than that in gas period. Hence, reasonable measures should be taken to reduce banking operation, especially in the situation of large excess air ratio. Since NOx formed during the whole operation process, the most effective way of preventing liquid water and HNO3 generation is to control the pipe and shell temperature, which should be higher than the condensa- tion temperature of water vapour. The condensation temperature should be considered as the design temperature of pipe and shell for hot stove.展开更多
The computer simulation of the combustion process in blast furnace(BF) stove has been studied by using the k-ε-g turbulent diffusion flame model.The combustion process in blunt annular ceramic burner was calculated b...The computer simulation of the combustion process in blast furnace(BF) stove has been studied by using the k-ε-g turbulent diffusion flame model.The combustion process in blunt annular ceramic burner was calculated by using the software.The profiles of gas and air velocity,temperature of the combustion products,concentration of the components,and the shape and length of the flame during combustion have been researched.Compared with the original annular ceramic burner,the new design of the blunt one improves the mixing of the gas and the air significantly,and shortened the length of the flame.展开更多
基金funded by the Research and Innovation Action project BIO4AFRICA implemented under European Union Funding for Research&Innovation,EU HORIZON 2020(Grant Agreement No.101000762)。
文摘In this article,we evaluated the energy performance parameters and gas emissions to identify which of the stoves studied performs best,and the biomass char briquettes with less emission.Biomass char briquettes from peanut shells,cashew nut shells,and corn cobs were produced using wheat flour as a binder.The binder rate was set at 9%and 10%.Based on the energy performance parameters,it was highlighted that the char briquette from corn cob with 9%binder(Char_CC_9%)has the best energy performance,followed by the char briquette from peanut shells with 9%binder(Char_PNS_9%),and lastly,the char briquette from cashew nut shells with 10%binder(Char_CNS_10%).The average energy efficiency of the“jambar”stove was 15.68%,while that of the“Malgache”stove was 12.41%.The average specific fuel consumption of the“jambar”stove was 0.12 kg of fuel per kilogram of water while that of the“Malgache”stove was 0.15 kg of fuel per kilogram of water.In terms of gaseous emissions,CO(carbon monoxide)concentrations were very high for char briquettes from corn cobs,with a CO emission factor of 0.40 g/min and NOx emission factor of 9.79 mg/min.For char briquettes from cashew nut shells,CO and NOx emission factors were respectively 0.30 g/min and 5.32 mg/min.The lowest average concentrations were obtained with char briquettes from peanut shells with a CO emission factor of 0.25 g/min and NO_(x) 3.98 mg/min.
基金Natural Science Foundation Committee of China(No.41390240,41130754,and 41161160559)National Basic Research Program of China(No.2014CB441101)+1 种基金Science&Technology Basic Special Fund(No.2013FY111100-04)Global Alliance for Clean Cookstoves under PR-15-39809
文摘Household air pollution is considered to be among the top environmental risks in China.To examine the performance of improved stoves for reduction of indoor particulate matter（PM） emission and exposure in rural households, individual inhalation exposure to size-resolved PM was investigated using personal portable samplers carried by residents using wood gasifier stoves or improved coal stoves in a rural county in Central China.Concentrations of PM with different sizes in stationary indoor and outdoor air were also monitored at paired sites. The stationary concentrations of size-resolved PM in indoor air were greater than those in outdoor air, especially finer particles PM0.25. The daily averaged exposure concentrations of PM0.25, PM1.0, PM2.5 and total suspended particle for all the surveyed residents were 74.4 ± 41.1, 159.3 ± 74.3, 176.7 ± 78.1 and 217.9 ± 78.1 μg/m3,respectively. Even using the improved stoves, the individual exposure to indoor PM far exceeded the air quality guideline by WHO at 25 μg/m3. Submicron particles PM1.0 were the dominant PM fraction for personal exposure and indoor and outdoor air. Personal exposure exhibited a closer correlation with indoor PM concentrations than that for outdoor concentrations. Both inhalation exposure and indoor air PM concentrations in the rural households with gasifier firewood stoves were evidently lower than the reported results using traditional firewood stoves. However, local governments in the studied rural areas should exercise caution when widely and hastily promoting gasifier firewood stoves in place of improved coal stoves, due to the higher PM levels in indoor and outdoor air and personal inhaled exposure.
文摘Exposure to high PM10 by women and children for hours on a daily basis in poor ventilated kitchen may lead to respiratory morbidity among this vulnerable group. In Nigeria, data on the levels of air pollutants associated with kerosene stove combustion are very scarce. Like-wise little had been documented on the pulmonary health of women exposed to kerosene stove emission. This study was carried out to measure the levels of kerosene combustion emissions within kitchen environments and also assess the pulmonary function status of the exposed women at baseline. Particulate matter (PM10) and gaseous emissions (GE) were measured in six purposively selected clusters of regular kerosene stove users (KSU) using gravimetric sampler and gas monitors, respectively and their values compared with WHO guideline limits. 167 randomly selected KSU were surveyed to elicit their socio demographic features. A spirometer was used to assess the lung function status (FEV1) of 72 KSU in six neighbourhood kitchen clusters. Data were analysed using descriptive statistics, and Pearson’s correlation tests. Respondents’ mean age was 38 + 12.9 years. Mean duration of exposure to GE was 18.9 + 9.8 years. Mean PM10 was 248.1 + 14.1 μg/m3 and ten folds higher than WHO guideline limit of 25 μg/m3. Mean GE in ppm were: CO (0.00), CO2 (200.1 + 12.4), SO2 (0.01 + 0.00) and NO2 (0.00). Mean FEV1 among KSU was 2.0 + 0.5 litres which was significantly lower than the mean predicted value of 2.7 ± 0.5 litres. There was a negative correlation between PM10 and FEV1 (r = -0.7539, p > 0.05). Safer cooking methods and practices to obviate health hazards are advocated.
文摘It is estimated that more than 2.5 billion people worldwide use biomass for cooking. Burning biomass is one of the major contributors to carbon dioxide (CO2) emission—a principle gas in global warming and climate change. One way of cutting down the CO2 emissions is adaptation of efficient and clean energy technologies. This study examined the efficiency of the energy saving stoves in Amboseli ecosystem by comparing the cooking time, energy use, wood fuel and carbon emissions to the traditional three stone open fire set ups. The result indicates a statistical difference in the time spent cooking on energy stoves and three stone open fire (t = 5.3055;n = 60;p = 0.00117). Energy saving stoves saved 12.7% - 33.3% of wood fuel compared to the traditional three stones set ups. Water boiling tests to determine the energy savings, revealed that energy saving stoves saved between 25.74% and 26.16% energy/joule per session in-house and outdoor settings respectively. Based on the two meals prepared per day by each household, the total Carbon Emission Savings for the 1000 local beneficiaries of energy saving stoves varied from 102,200 kg CO2 (indoor cooking) to 357,700 kg CO2 (outdoor cooking) per year. It is therefore concluded that energy saving stoves saves time, fuel wood and energy, and reduces carbon emissions. The study findings refute the claims that open fire when carefully operated can be fuel efficient and clean burning to rival energy saving stoves. To improve the performance of the energy saving stoves, it is recommended that a design modification be done to include a chimney to emit excess smoke during indoor cooking;and the stove should be fixed to the floor with mortar to minimise heat loss and breakages.
文摘An earthen kitchen stove caught my attention on a recent visit to the Tibet Museum, as such a stove, commonly used by the Tibetans only a dozen years ago, can hardly be found today in the region.Varieties of StovesTibetans used a variety of stoves in the past. For instance, they used rectangular stoves with several pots, and oval stoves to press edible oil. Monastery monks adopted types that were sometimes as large as a small room. Ordinary Tibetans had the following four kinds of stoves for cooking:
基金supported by the Ministry of Science and Technology of China(No.2017YFC0211400)and the China Office of Clean Air Asia.
文摘Straw pellets are widely promoted and expected to be a cleaner alternative fuel to unprocessed crop residues and rawcoal in rural China.However,the effectiveness of these dissemination programs is not well evaluated.In this field study,emission characteristics of burning strawpellets,rawcoal,and unprocessed corn cobs in heating stoveswere investigated in a pilot village in Northeast China.Emission measurements covering the whole combustion cycle(ignition,flaming,and smoldering phases)shows the promotion of improved heating stoves and straw pellets could reduce pollutant emissions(e.g.,SO_(2) and CO),but increase NO_(X) and PM_(2.5) emissions compared to the initial stove-fuel use pattern in the studied area.There is a significant variance in emission characteristics between different combustion phases.The normalized emission concentrations of the different stove-fuel combinations were higher than the limits in the Chinese national standard for heating stoves,indicating that the standard is not met for real-world emissions.Coal consumption was lower than official data.Household surveys were conducted to identify the barriers to fuel and stove access associated with existing promotion strategies,management,and policies.The pilot program was of the typical“subsidy-and-policy-dependence”pattern and was unlikely to be implemented on a large scale.Technological innovation,operational optimization,and proper policies considering the local socioeconomic factors are needed to sustain the promotion of biomass straw pellets and stoves.
文摘Biochar is a solid material obtained from the carbonization of biomass. Biochar is used on agricultural lands as a soil amendment to improve the fertility of the soils. Currently the most common method of producing biochar is through biochar stoves. There are two basic stove operations in the production of biochar. The first type of stove produces biochar by direct combustion of biomass. Here biomass is burnt inside a chamber in an oxygen limited environment. The resulting residue is the bio-char. The second type involves burning the biomass in one chamber and housing the biomass to be charred in the annular portion of an outer chamber. Heat is transferred from the burning fuel on the inner chamber to the material to be charred in the outer chamber. While the process of biochar production in these stoves is known, the basic principles of the stove design are not readily available. The design methodology for both the types was developed from first principles. Prototypes of both types were constructed based on the design developed and tested. The paper lists the basic principles in the design of biochar stoves and the test results.
文摘The Design of Experiments (DOE) and the Analysis of Variance (ANOVA) are used to determine the effect of fuel type, fuel initial load, secondary air inlet and ventilation on thermal efficiency and CO emission of two biomass fire cookstoves during boiling or simmering. Analysis of variance with Fischer’s statistical test (F-test) and Newman-Keuls test were applied to establish the influence of the independent parameters on the studied responses. The results of this study are useful to application of charcoal cooks stoves.
基金This research was supported by the National Natural Science Foundation of China(Grant No.51806242)the Chinese Universities Scientific Fund(No.2019TC010)+3 种基金the Chinese Universities Scientific Fund-Special Project for"Double First-Class"Initiative of College of Engineering,China Agricultural University,"the Characteristics of Thermal and Mass Flow for Clean Space-heating of Rural Households using Biofuels"the Agricultural Product Quality Inspection Bureau,Ministry of Agriculture and Rural Affairs,China,Agricultural Industry Standard Development Project-"Determination method of major atmospheric pollutants from rural household stoves"(No.181721301092371112)the bilateral China-South Africa MoST-NRF joint project“Development of Scientifically Robust and Culturally Appropriate Metrics and Protocols for Evaluating Clean(Combustion)Cooking Stoves”,sponsored by Ministry of Science and Technology,ChinaInvestigation on South-South Cooperation in Climate Change through Clean Stove Alliance,sponsored by Ministry of Ecology and Environment and Administrative Center for China's Agenda 21(No.0201835).
文摘The extensive use of traditional cooking and heating stoves to meet domestic requirements creates a serious problem of indoor and outdoor air pollution.This study reports the impacts of two fuel feeding methods-front-loading and top-loading on the thermal and emissions performance of a modern coal-fired water-heating and cooking stove using a contextual test sequence that replicates typical patterns of domestic use.Known as a low-pressure boiler,when this stove was fueled with raw coal,the findings indicate that front-loading the fuel,which devolatilizes the new fuel gradually,produced consistently higher space heating efficiency and lower emission factors than top-loading the same stove,which devolatilizes new fuel all at once.Comparing the performance at both high and low power gave the similar results:front-loading with raw coal produced consistently better results than top-loading.The average water heating efficiency when front-loading was(58.6±2.3)%and(53.4±1.8)%for top-loading.Over the sixteen-hour test sequence,front-loading produced 22%lower emissions of PM2.5(3.9±0.6)mg/MJNET than top-loading(4.7±0.9)mg/MJNET.The same pattern was observed for carbon monoxide and the CO/CO2 ratio.CO was reduced from(5.0±0.4)g/MJNET to(4.1±0.5)g/MJNET.The combustion efficiency(CO/CO2 ratio)improved from(8.2±0.8)%to(6.6±0.6)%.Briquetted semi-coked coal briquettes are promoted as a raw coal substitute,and the tests were replicated using this fuel.Again,the same pattern of improved performance was observed.Front loading produced 3.5%higher heating efficiency,10%lower CO and a 0.9%lower CO/CO2 ratio.It is concluded that,compared with top loading,the manufacturers recommended front-loading refueling behavior delivered better thermal,emissions and combustion performance under all test conditions with those two fuels.
文摘Last Sunday,I felt very hungry when I got up late.There was no food in the fridge,so l decided to cook noodles for me①.First,I filled the pot with water and put it on the stove.I waited patiently for the water to boil.Then,I put the noodles into the boiling water.Next,I added some vegetables,an egg,and a little salt.
基金supported by Ningxia Natural Science Foundation Innovative Group Project(2023AAC01001)the Postdoctoral Research Excellence Funding Project of Zhejiang Province ofChina(ZJ2023135).
文摘This study systematically investigated the effects of different gas stove structures on flame combustion characteristics using spectral diagnostic techniques,aiming to provide optimized design guidelines for clean energy applications.To explore the combustion behaviors of various gas stove structures,UV cameras,high-speed cameras,and K-type thermocouples were employed to measure parameters such as flame OH radicals(OH*),flame morphology,pulsation frequency,flame temperature,and heat flux.The results demonstrate that flame stability was achieved at an inner/outer cover flow rate ratio of 0.5/4.0 L/min,beyond which further flow rate increases led to reduced combustion efficiency.Compared to covered stoves,top-uncovered stove exhibited 5.5%and 12.4%higher temperatures at the inner and outer covers,respectively,along with a 35%increase in heat flux.Comprehensive analysis revealed an approximately 20%enhancement in overall flame intensity.The experimental results show that top-uncovered gas stoves exhibit higher flame intensity,greater combustion efficiency,and overall higher stove efficiency.In contrast,covered gas stoves feature a more controllable and stable flame with a gentler temperature rise.This study underscores the importance of optimizing gas stove designs to enhance combustion efficiency and reduce emissions,contributing to the transition from fossil fuels to renewable energy sources and promoting sustainable development.
文摘The main function of a hot blast stove is to deliver a high-temperature and stable hot blast to the blast furnace,which has an important impact on the blast furnace ironmaking process.To improve the combustion efficiency,a simulation model of the combustion part of an internal combustion hot blast stove was established by combining turbulence,combustion,and radiation models.Based on the original model,a new type of internal combustion hot blast stove is proposed.The results indicated insufficient combustion in the original structure and higher CO concentrations in the corners of the eyes at both ends of the combustor outlet,the recirculation area at the bottom of the combustion chamber was mainly concentrated in the middle part.With the new structure of the hot blast stove,the gas baffles with different inclination angles are added to the rectangular burner,at the outlet of the combustion chamber,the CO concentration is reduced to a certain extent,and the temperature distribution is more uniform.When the inclination angle of the gas baffle is 60°,the combustion chamber outlet section average temperature rises from 1686 K to 1693 K,the outlet flue gas average volume fraction of CO decreases the most,and the average volume fraction of CO decreases from 0.00708%to 0.00568%,which could reduce the CO content by about 20%.
基金supported in part by Agricultural Product Quality Inspection Bureau Project-Agricultural Industry Standard Development for“Determination method of major atomosphere pollutants from rural household stoves”(No.181721301092371112)the bilateral China-South Africa MoST-NRF joint project“Development of Scientifically Robust and Culturally Appropriate Metrics and Protocols for Evaluating Clean(Combustion)Cookstoves”+1 种基金the World Bank Group Project for“Clean and Efficient Heating Stove South-South Knowledge Exchange”(No.7182688)the Project for“China-Ghana Renewable Energy Technology Transfer Cooperation”(No.CG211/2-3)from the Administrative Center for China's Agenda 21.
文摘Charcoal stove is widely used in the developing countries especially in Africa and Central America.Even reported to have a high impact on human health,stoves promoted in the related areas still mainly focus on fuel saving and little knowledge was reported for the stove performance in the field.This research evaluated four commercialized charcoal stoves with clay baseline stove using a modified Chinese cooking stove protocol that considered the local cooking habit to make the testing results more useful for the local stove promotion.The results showed that the thermal efficiency of tested charcoal stoves ranged from 38.7%to 47.5%,and the cooking power was around 640-1200 W.The CO emission factors of the improved stove had a 60%reduction compared with baseline stove.Different indicators reporting the same aspect of the stove were evaluated,and it suggested choosing the indicators according to the project requirements.
文摘The sustainable land management (SLM) project is seeking to engage with public institutions to explore the possibility of using the energy-switch principle presented by the carbon market to reduce emissions from inefficient use of biomass energy and discharge of human waste into the environment. Such a switch will be a triple-win situation that improves the natural environment, reduces deforestation, and provides avenues for revenue generation. As such, it commissioned a study of the pattern of energy consumption in the institutions and the type of cooking stoves they employ. Results show that firewood (51%) is the most widely used fuel because of availability, affordability, and reliability. The study also found that 56% of the institutions use energy-saving stoves, which is an opportunity that the project can seize to encourage use of alternatives sources of energy as opposed to biomass. In addition, 88% of the institutions expressed willingness to switch to biogas for cooking. This is yet another opportunity for scaling up the dissemination of renewable sources of energy in the region. Better adoption and wider use of renewable energy sources will take place when innovative financing mechanisms are devised to cover the high upfront cost of installing renewable energy systems. This has been one of the main barriers to scaling up the use of renewable in the region.
文摘Many communities across the globe still practice poor cooking cultures as part of their well-being to prepare food and other heating activities. Such bad cooking practices are not environmentally friendly, are wasteful </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> have adverse health effects. This work presents the results of the survey that was conducted to establish the existing cooking practices commonly used in Uganda, identify the commonly used fuel during cooking, identify perceptions on improved cooking stoves (ICS), perceived preferences during cooking as well as identify whether users are aware of the health challenges due to poor cooking and describe community opinions of ICS for rural communities in Uganda. The interviews were conducted on household levels across all the regions covering Uganda’s major rural regions. It was observed that </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">largest</span><span style="font-family:""><span style="font-family:Verdana;"> population of rural Ugandans still use the 3 stone stove fire for cooking with a percentage of 53.5%, Charcoal stove, 27.3%, Improved cooking stove, 16.9%, Electric cookers,1.2%, LPG 0.7% </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> biogas 0.5% for the preparation of their various types of cooked foods while forest firewood is the commonly used biomass fuel for cooking with a percentage of 66.8% compared to Charcoal, Briquettes, </span><span style="font-family:Verdana;">Saw dust</span><span style="font-family:Verdana;"> and others with a percentage of 27.1%, 0.7%, 0.7%, 1.1% respectively. This reveals the great majority of users whose life is at risk as 3 stone stoves are characterized by low efficiency and high smoke production which increases the health risks of the users as well as increase the risk of deforestation rates. Household cooks showed great willingness to pay for a novel stove type in all </span><span style="font-family:Verdana;">the 4</span><span style="font-family:Verdana;"> regions but from the survey data, it was indicated that the preferences varied from one region to another with a great majority preferring minimal smoke production with increased heat retention capacity. It was revealed that 91.4% of the interviewed households were aware of the health challenges due to poor cooking methods which they resolve</span></span><span style="font-family:Verdana;">d</span><span style="font-family:""><span style="font-family:Verdana;"> by using open space during cooking. There was variation in the quantity of food cooked in a day, time spent on cooking </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> how often the cooking is done from one region to another due to the difference in economic activities as well as the different climate factors. While using cooking stoves, users preferred large cooking pot space with minimal smoke production and rapid heating. Such information can act as a basis for the design of an improved cooking stove for the rural Ugandan community as engineered products must be designed to suit the needs of the end-user.
文摘In Shougang Jingtang 5 500m 3 huge blast furnace ( BF ) design , dome combustion hot blast stove ( DCHBS ) technology is developed.DCHBS process is optimized and integrated , and reasonable hot blast stove ( HBS ) technical parameters are determined.Mathematic model is established and adopted by computational fluid dynamics ( CFD ) .The transmission theory is studied for hot blast stove combustion and gas flow , and distribution results of HBS velocity field , CO density field and temperature field are achieved.Physical test model and hot trail unit are established , and the numeral calculation result is verified through test and investigation.3-D simulation design is adopted.HBS process flow and process layout are optimized and designed.Combustion air two-stage high temperature preheating technology is designed and developed.Two sets of small size DCHBSs are adopted to preheat the combustion air to 520-600℃.With the precondition of BF gas combustion , the hot blast stove dome temperature can exceed 1 420 ℃. According to DCHBS technical features , reasonable refractory structure is designed.Effective technical measures are adopted to prevent hot blast stove shell intercrystalline stress corrosion.Hot blast stove hot pipe and lining system are optimized and designed.After blowing in , the blast temperature keeps increasing , and the monthly average blast temperature reaches 1 300℃ when burning single BF gas.
基金Sponsored by National Natural Science Foundation of China(61271303)
文摘Hazard control of NOx is very important for the long life of hot stove shell and environmental protection. NOx concentrations during different operation periods of hot stove were calculated according to thermodynamical and dynamical analyses. The results were verified by the previously measured data. Then, the influence of hot stove oper- ation parameters on NOx concentration and the mechanism of liquid water formation in hot stove were studied. The results indicated that in gas period, the dome temperature should be controlled below 1420 ℃ in order to decrease NO~ emission. In the case of banking operation, NOx concentration was about 40--60 times higher than that in gas period. Hence, reasonable measures should be taken to reduce banking operation, especially in the situation of large excess air ratio. Since NOx formed during the whole operation process, the most effective way of preventing liquid water and HNO3 generation is to control the pipe and shell temperature, which should be higher than the condensa- tion temperature of water vapour. The condensation temperature should be considered as the design temperature of pipe and shell for hot stove.
基金Item Sponsored by National Natural Science Foundation(50104001)Science and Technology Tackle Key Foundation of Inner Mongolia(980307-4)
文摘The computer simulation of the combustion process in blast furnace(BF) stove has been studied by using the k-ε-g turbulent diffusion flame model.The combustion process in blunt annular ceramic burner was calculated by using the software.The profiles of gas and air velocity,temperature of the combustion products,concentration of the components,and the shape and length of the flame during combustion have been researched.Compared with the original annular ceramic burner,the new design of the blunt one improves the mixing of the gas and the air significantly,and shortened the length of the flame.
