家用生物质颗粒燃料炉的研制

为解决农村秸秆焚烧污染问题，研究以生物质颗粒为燃料的家用生物质颗粒燃料炉供农家炊事使用。在充分研究、分析生物质颗粒燃料燃烧动力学特性的基础上，根据生物质颗粒燃料挥发分含量高、燃点低的特点，在生物质颗粒燃料炉的设计中采用了气化、燃烧一体化结构。测试结果表明，生物质颗粒燃料在生物质颗粒燃料炉内能气化燃烧，残碳也能够完全燃尽。该炉的主要技术指标均符合国家标准，燃烧稳定、高效、清洁，提高了秸秆的能源利用率。     

助燃空气温度对生物质成型燃料炉点火过程污染物排放的影响

以生物质成型燃料炉为对象,分别燃用玉米秸秆和木质成型燃料,分析其不同助燃空气温度下的点火过程中污染物(NO,CO)的排放规律.试验结果表明:点火过程,NO的平均排放质量比稳态时的要低,而CO的平均排放质量比稳态时的要高.燃用玉米秸秆成型燃料,CO与NO的质量比随排烟温度呈指数关系减小,燃用木质成型燃料,CO与NO的质量...     

Numerical investigation of the flow inside the combustion chamber of a plant oil stove

Recently a low cost cooking device for developing and emerging countries was developed at KIT in cooperation with the company Bosch und Siemens Hausger te GmbH.After constructing an innovative basic design further development was required.Numerical investigations were conducted in order to investigate the flow inside the combustion chamber of the stove under variation of different geometrical parameters.Beyond the performance improvement a further reason of the investigations was to rate the effects of manufacturing tolerance problems.In this paper the numerical investigation of a plant oil stove by means of RANS simulation will be presented.In order to reduce the computational costs different model reduction steps were necessary.The simulation results of the basic configuration compare very well with experimental measurements and problematic behaviors of the actual stove design could be explained by the investigation.     

Experimental investigation of the performance of a liquid fuel-fired porous burner operating on kerosene-vegetable cooking oil (VCO) blends for micro-cogeneration of thermoelectric power

Studies related to porous burner for thermoelectric (TE) power generation have mainly focused toward achieving a specific range of power output for various applications. However, detailed analyses on the performance and emission aspects of the porous burner are lacking. In addition, physical integration between the burner and TE modules has added further complexity in this research area. Thus, this work aims to comprehend the effects of fuel–air equivalence ratio on the performance and emission characteristics of a liquid fuel-fired porous burner for micro-cogeneration of TE power. A catalytically inert Al₂O₃ porous medium was incorporated into a liquid fuel-fired porous burner operating on four mixtures of kerosene-vegetable cooking oil (VCO) blends: 100 kerosene, 90/10 KVCO, 75/25 KVCO, and 50/50 KVCO. Ten bismuth-telluride TE cells were arranged in a ten-sided polygon that, together with finned dissipators, formed a TE module electrically connected in series but thermally connected in parallel. The performance aspects at various fuel–air equivalence ratios were thoroughly evaluated with the corresponding temperature profiles, voltage, current, power output, and electrical efficiency. Results indicated that the surface temperature of the porous media was generally higher than the developed and exit flame temperature of the burner. Varying the fuel-air equivalence ratio significantly affected the electrical efficiency, with a maximum and minimum value of 1.94% and 1.10%, respectively. The power output steadily increased in the lean region, but stabilized as the fuel–air equivalence ratio slowly increased beyond the stoichiometric ratio. The CO emission was relatively lower at the lean region; however, significant amount was recorded in the rich combustion region. Moreover, NOx fluctuated between 1 ppm and 4 ppm over the entire range of fuel–air equivalence ratio.     

鼓风式灶用燃烧器燃料与助燃风适配性研究

标定了鼓风式燃气灶助燃风机进口挡板在不同位置时的风量和压头,并计算出相应位置所需的燃气量,使得燃气灶在不同功率负荷下助燃风量和燃料量的匹配得到优化,以提高其热效率并降低污染物排放量。     

餐饮油烟排放在线监测仪器研究现状与进展

目前餐饮油烟是城市大气环境的主要污染源之一,会对人体造成大量伤害。针对餐饮油烟排放监测,阐述了餐饮油烟排放量大且复杂的现状及排放要求对测量要求的影响,综述了现有餐饮油烟排放检测方法及仪器的原理、特点及测量缺陷,并对餐饮油烟排放在线监测仪器发展趋势进行了展望。提出了针对餐饮油烟测量的技术方案,以期为餐饮油烟在线测量提供一种可行的技术方案。     

家用燃气灶热效率测量及不确定度评定

按照GB16410-2007家用燃气灶热效率的测量原理和方法,对测量结果进行了不确定度评定,分析了各输入量对评定结果的影响情况。作为对比,分析了标准状态改变和按旧国标测量时的热效率不确定度。结果表明:铝锅修正系数、上下限锅正投影面积、试验气标态低热值和水的温升对家用灶热效率测量结果影响较大,影响程度依次降低。折算系数、测量时间和实验水量的测量不确定度可忽略不计。标准状态的改变对热效率测量结果不确定度评定的影响很小。相比旧国标,新国标测量结果具有更大的不确定度。     

Modeling and design of a solar thermal system for hybrid cooking application

This paper proposes a hybrid solar cooking system where the solar energy is brought to the kitchen. The energy source is a combination of the solar thermal energy and the Liquefied Petroleum Gas (LPG) that is in common use in kitchens. The solar thermal energy is transferred to the kitchen by means of a circulating fluid. The transfer of solar heat is a twofold process wherein the energy from the collector is transferred first to an intermediate energy storage buffer and the energy is subsequently transferred from the buffer to the cooking load. There are three parameters that are controlled in order to maximize the energy transfer from the collector to the load viz. the fluid flow rate from collector to buffer, fluid flow rate from buffer to load and the diameter of the pipes. This is a complex multi energy domain system comprising energy flow across several domains such as thermal, electrical and hydraulic. The entire system is modeled using the bond graph approach with seamless integration of the power flow in these domains. A method to estimate different parameters of the practical cooking system is also explained. Design and life cycle costing of the system is also discussed. The modeled system is simulated and the results are validated experimentally.     

Laboratory based assessment of cookstove performance using energy and emission parameters for North Indian cooking cycle

The study was conducted to evaluate the performance of cookstoves using controlled cooking test (CCT) with cooking cycles of Northern India, i.e., Uttar Pradesh (UP) and Uttarakhand (UK). Cooking time, specific energy consumption (SEC), and emission factors (EFs) of carbon monoxide (CO) and particulate matter (PM) were monitored for three improved and one traditional cookstoves. Cooking was conducted by residents of the study area. The findings from the study showed that the difference in thickness of roti baked in UP and UK resulted in a significant change in emission and energy performance in all the four cookstoves. The low-power inputs required for baking thinner roti resulted in higher CO and PM emissions in case of CCT-UK. The results of CCT were also compared to Water Boiling Test (WBT) for all the four cookstoves. The percent reductions in terms of energy and emission parameters in the three improved cookstoves compared to traditional cookstove were found to differ in CCT and WBT. Large variations were also observed during the emission performance (40% decrease in CO EF) of the fan cookstove with change in fan speed, which was usually unreported in previous studies. Overall, results show significant influence of cooking cycles on cookstove performance, which was found to alter the cookstove rankings. Therefore, the study thrusts upon the inclusion of user centric cookstove testing protocols in order to identify actual benefits for targeted rural communities.     

Effect of utilization of hydrogen-rich reformed biogas on the performance and emission characteristics of common rail diesel engine

The utilization of renewable gaseous fuels in the diesel engine has gained significant interest in recent years due to its clean-burning nature and higher availability. In this study, hydrogen-rich reformed biogas was used as a gaseous fuel in a common rail diesel engine with diesel as pilot fuel. The hydrogen-rich reformed gas was synthesized through dry-oxidative reforming. The experimentations were performed in the load range from 6 to 24 N m with two different flow rates of gaseous fuel (0.5 and 1.5 kg/h) at a constant speed of 1800 RPM. The effects on engine performance parameters (brake thermal efficiency, brake specific energy consumption, and brake specific diesel consumption), combustion parameters (rate of pressure rise and maximum heat release rate) and emission parameters (Unburnt hydrocarbons, nitrogen oxides, carbon monoxide, and carbon dioxide) were assessed. The induction of gaseous fuel led to an increase in brake thermal efficiency by 10.5%, reduction in brake specific energy consumption by 13.6%, and a reduction of 26.4% in brake specific diesel consumption with a flow rate of 0.5 kg/h when compared to diesel-only mode at 24 N m load. The HC, NO_X and CO₂ emissions were reduced by 18.2%, 7.4% and 1.4% with a flow rate of 0.5 kg/h when compared to diesel-only mode at 24 N m load due to lower availability of carbon content in the combustible mixture. The utilization of renewable fuel like hydrogen-rich reformed biogas has great potential for overcoming the issue related to both biogas and hydrogen in diesel engines. Moreover, the higher diesel substitution also demonstrates the potential for cost-saving and fossil fuel conservation.     

上吸式生物质秸秆气化炉的设计与试验研究

设计一台上吸式生物质秸秆气化炉,并进行热解气化试验,分析不同气化剂量对炉内温度的影响以及温度和秸秆种类对产气成分的影响。试验结果表明：气化剂量对炉内温度及炉内温度对产气成分含量的影响均较大;秸秆种类也对产气的热值有较大的影响,稻草热解可燃气热值4．1MJ／m^3,油菜秆热解可燃气热值4．9MJ／m^3,玉米秆热解可燃气热值5．5MJ／m^3。     

锅炉与炉窑燃料油使用中的常见问题及解决方法

对燃油锅炉与炉窑使用中的常见问题以及燃料油主要质量指标的优劣对燃烧工况的关联影响进行分析，并提出一种经济实用简便的解决方法，达到改善燃油锅炉与炉窑燃烧工况与抑制硫、钒的腐蚀，灰分积焦、积炭、油泥生成等，又达到降低能耗、减少烟气排放的目的。     

Performance,emission and combustion characteristics of a variable compression ratio engine using methyl esters of waste cooking oil and diesel blends

The performance, emission and combustion characteristics of a single cylinder four stroke variable compression ratio multi fuel engine when fueled with waste cooking oil methyl ester and its 20%, 40%, 60% and 80% blends with diesel (on a volume basis) are investigated and compared with standard diesel. The suitability of waste cooking oil methyl ester as a biofuel has been established in this study. Bio diesel produced from waste sun flower oil by transesterification process has been used in this study. Experiment has been conducted at a fixed engine speed of 1500 rpm, 50% load and at compression ratios of 18:1, 19:1, 20:1, 21:1 and 22:1. The impact of compression ratio on fuel consumption, combustion pressures and exhaust gas emissions has been investigated and presented. Optimum compression ratio which gives best performance has been identified. The results indicate longer ignition delay, maximum rate of pressure rise, lower heat release rate and higher mass fraction burnt at higher compression ratio for waste cooking oil methyl ester when compared to that of diesel. The brake thermal efficiency at 50% load for waste cooking oil methyl ester blends and diesel has been calculated and the blend B40 is found to give maximum thermal efficiency. The blends when used as fuel results in reduction of carbon monoxide, hydrocarbon and increase in nitrogen oxides emissions.     

甘氨酸钠溶液提纯沼气性能的试验研究

对新型有机胺-甘氨酸钠溶液吸收CO2提纯沼气的适宜条件进行了试验研究,并采用加热再生的方法对甘氨酸钠溶液的再生性能进行了研究。考察了不同浓度(0.5～3 mol/L)甘氨酸钠溶液对CO2吸收速率和吸收负荷随时间的变化关系,气流速度对于甘氨酸钠溶液对CO2吸收速率和吸收负荷的影响以及温度对于甘氨酸钠溶液对CO2吸收速率的影响。试验结果表明,甘氨酸钠溶液的浓度越高,吸收量也越大,但吸收负荷越小;气流速度对甘氨酸钠吸收CO2速率影响较为明显;温度对甘氨酸钠吸收CO2速率影响较小。另外,甘氨酸钠溶液具有稳定的再生性能,适宜的再生温度和再生时间分别为108℃和3 h。     

户用秸秆压块采暖装备优化设计与试验

北方农村地区以廉价秸秆压块燃料采暖是实现化石能源替代、减少污染物排放的重要措施。然而高效秸秆压块采暖炉的缺乏成为制约其发展的瓶颈。本文结合压块燃料燃烧特性,对前期研发的秸秆压块采暖装备进行优化设计与试验测试。结果表明：优化后自动送料装置可实现12h无人值守,炉膛内火焰脉动强烈;烟气中NO_x浓度、CO浓度、烟尘浓度分别为62.48mg/m^₃、522.04mg/m^₃、31.1mg/m^₃,降幅率分别为31.5%、46.8%、35.2%;林格曼烟气黑度小于1,额定热功率为10.19kW;热效率为84.69%,提高6.54%。     

Effect of methanol fumigation on performance and emission characteristics in a waste cooking oil-fuelled single cylinder CI engine

Use of bio-oils in diesel engines results in increased NOx and smoke and reduced brake thermal efficiency. Dual-fuel engines can use a wide range of fuels mainly alcohols and yet operate with high thermal efficiency and simultaneous reduction of NO and smoke emissions. The present study aims to explore the effect of methanol–waste cooking oil (WCO) dual-fuel mode on performance and emission characteristics in a single cylinder Compression ignition (CI) engine producing 3.7 kW at 1,500 rpm. WCO was injected in the conventional injection system, replacing diesel as pilot fuel. Methanol was fumigated along with intake air using a variable jet carburetor, which was installed in the inlet manifold. The methanol was fumigated, and the energy share was varied for each load till the knock limit. Performance parameters like brake thermal efficiency (BTE) and emission parameters like HC, CO, NO, and smoke emissions were tested for various energy shares of methanol with WCO as a pilot fuel. The results show that an increase in methanol fumigation reduced BTE at lower loads. At 75% and 100% load conditions, BTE was higher with methanol addition. The maximum BTE was observed for 38% methanol share, which is about 11% higher, compared to WCO at 100% load condition. Methanol fumigation aided in the simultaneous reduction of NO and smoke emission, and the maximum reduction was occurred with 51% methanol share at 100% load condition. HC and CO emissions were higher at all load conditions with methanol fumigation.     

Performance evaluation of a constant speed IC engine on CNG,methane enriched biogas and biogas

This paper presents the performance results of a 5.9 kW stationary diesel engine which was converted into spark ignition mode and run on compressed natural gas (CNG), methane enriched biogas (Bio-CNG) and biogas produced from biomethanation of jatropha and pongamia oil seed cakes. The performance of the engine with 12.65 compression ratio was evaluated at 30°, 35° and 40° ignition advance of TDC. The maximum brake power produced by the engine was found at ignition advance of 35° TDC for all the tested fuels. In comparison to diesel as original fuel, the power deteriorations of the engine was observed to be 31.8%, 35.6% and 46.3% on compressed natural gas, methane enriched biogas and raw biogas, respectively, due to its conversion from CI to SI mode. The methane enriched biogas showed almost similar engine performance as compared to compressed natural gas in terms of brake power output, specific gas consumption and thermal efficiency.     

Design and performance evaluation of a 5 kW producer gas stove

The paper addresses the studies of a wood gas stove in meeting cooking energy requirement using biomass gasification. The stove works on natural draft mode. The thermal efficiency of the stove was recorded at about 26.5% and it can be started, operated and stopped with very low emissions. It can use a wide variety of biomass fuels. The produced wood gas burns with a blue flame like liquid petroleum gas with a flame temperature of 736 °C. The design criteria, safety measures and operating procedure of wood gas stoves are presented in this paper.     

Evaluation of the performance of improved biomass cooking stoves with different solid biomass fuel types

We have studied the performance of different types of improved solid biomass cookstoves (Two natural draft and one forced draft) in comparison to the traditional cookstove (control) while preparing a particular meal with a variety of solid biomass fuels (e.g. fuel wood, dung cake and crop residue). Five replicates of each type of cookstove and fuel were maintained. The study was conducted in an Indian rural kitchen. There was no significant difference in the indoor concentrations of PM_2.5 and CO when natural draft and traditional cookstoves were used with any type of solid fuel. However, significantly lower concentrations of PM_2.5 and CO were recorded with forced draft stoves compared to others. While cooking with different types of solid biomass fuels, the concentrations of PM_2.5 and CO in the indoor environment were decreased by 21–57% and 30–74% respectively with the forced draft cookstove in comparison to the traditional cookstove. The fuel consumption, cooking duration and thermal efficiency of a particular stove to prepare a particular amount of food also differ depending on the type of the solid fuel used for the cooking purpose. The thermal efficiency of traditional, natural draft and FD cookstoves were in the range of 15–17%, 16–27% and 30–35% respectively for different types of solid biomass fuels. However, further studies on the performance of stoves are required based on the size and type of fuel wood or crop residues.     

A comprehensive study on performance,emission and combustion behavior of a compression ignition engine fuelled with WCO (waste cooking oil) emulsion as fuel

This work aims at evaluating the performance, emission and combustion of a diesel engine fuelled with WCO (waste cooking oil obtained from palm oil) and its emulsion as fuel. A single cylinder water-cooled diesel engine was used. Base data was generated with diesel and neat WCO as fuels. Subsequently, WCO oil was converted into its emulsion and tested. Neat WCO resulted in higher smoke, hydrocarbon and carbon monoxide emissions as compared to neat diesel. Significant reduction in all emission was achieved with the WCO emulsion. Cylinder peak pressure and maximum rate of pressure rise were found to be higher with WCO emulsion as compared to neat WCO mainly at high power outputs. Ignition delay was found as higher with neat WCO and its emulsion. It is concluded that WCO emulsion can be used in diesel engines without any modifications in the engine with superior performance and reduced emissions at high power outputs.