Off-grid solar cooking in the developed and developing regions of the world is becoming one response to climate change that causes wood-fuel shortages and an increase in cost of coal, gas, and electricity production a...Off-grid solar cooking in the developed and developing regions of the world is becoming one response to climate change that causes wood-fuel shortages and an increase in cost of coal, gas, and electricity production and their transportation. This paper examines a series unloaded temperature and loaded (food) performance metrics for an inclined window solar box cooker (SBC) designed for Mediterranean latitudes (35.31˚N, 24.31˚E). Solar radiation analysis using two different computer software platforms (SunCalc and Autodesk Revit® with insight plug-in software) is used to date and time-stamp the solar box cooker solar input power. Performed sensible heat tests demonstrate that the solar cooker can reach unloaded internal temperatures of 120˚C at a solar irradiance of 192 W, and a first figure of merit of 0.08 to 0.105. Food cooking metrics is performed on: whole eggs-without water, and the following with water;White medium-grain rice, rice pudding, pastitsio #2 pasta and Brown small lentils. The analytical metrics reveals that their required cooking power is 13 to 53 W;cooking energy of 94 to 210 kJ and energy density is 0.2 to 0.6 kJ⋅g−1. Using day and time-stamped computed solar input power the food cooking power efficiency varies between 6% to 8.9% for three whole eggs-without water, and 16% to 35.5% for rice, pasta, and lentils cooked in water. For water-stressed communities in traditional desert and emerging drought regions a mass-based wastewater/product metrics is used to help drive the water efficiency of the solar cooking process.展开更多
Recently, Shunde Electric Pressure Cooker Alliance （short for EPCA） successfully made four proposals on revision of the IEC international standard for electric pressure cooker with independent intellectual property ...Recently, Shunde Electric Pressure Cooker Alliance （short for EPCA） successfully made four proposals on revision of the IEC international standard for electric pressure cooker with independent intellectual property rights, namely Elastic Structure Design, Anti-blocking Safety, Pressure Relief Safety and Lid Closing Safety. In the mean time, when participating in the activities related with revision proposals on IEC standard Electric Pressure Cooker, EPCA makes full use of the information and experience gained in these activities, improves and put forward the new-edition Electric Pressure Cooker Alliance Standard （hereafter referred to as Alliance Standard）. This article is an interpretation with this Alliance Standard aiming at bettering the pressure cooker enterprises＇ understanding with this standard, so as to guide the alliance enterprises to highlight the differentiated characteristics and product features in the links like products design, procurement of raw and auxiliary materials, manufacturing and sales, etc., as well as to let industrial peers learn about the characteristics of this standard and the products.展开更多
In this work, a numerical study of heat transfers in a metallic pressure cooker isolated with kapok wool was carried out. This equipment works like a thermos, allowing finishing cooking meals only thanks to the heat s...In this work, a numerical study of heat transfers in a metallic pressure cooker isolated with kapok wool was carried out. This equipment works like a thermos, allowing finishing cooking meals only thanks to the heat stored at the beginning of cooking, which generates energy savings. Cooked meals are also kept hot for long hours. In our previous work, we have highlighted the performances of the pressure cooker when making common dishes in Burkina Faso. Also, the parameters (thickness and density) of the insulating matrix allowing having such performances as well as the influence of the climatic conditions on the pressure cooker operation were analyzed in detail in this present work. The numerical methodology is based on the nodal method and the transfer equations obtained by making an energy balance on each node have been discretized using an implicit scheme with finite differences and resolved by the Gauss algorithm. Numerical results validated experimentally show that the thickness of the kapok wool as well as its density play an important role in the pressure cooker operation. In addition, equipment performances are very little influenced by the weather conditions of the city of Ouagadougou (Burkina Faso).展开更多
Mathematical relations are developed to compute optimum inclination angle of booster mirror for horizontally placed cooker (λ) and for optimally inclined cooker (ψ) during all months (selected day) of the year at 30...Mathematical relations are developed to compute optimum inclination angle of booster mirror for horizontally placed cooker (λ) and for optimally inclined cooker (ψ) during all months (selected day) of the year at 30°N latitude for maximizing the reflected component of solar intensity onto the absorber plate of the cooker. A solar radiation model is also developed and used to compute the ratio of various solar intensities on horizontal, inclined and normal surface of the absorber plate for all months at 30°N latitude. These ratios give a clear indication of greater solar radiation availability on the optimally inclined cooker as compared to the horizontally placed cooker for faster cooking especially during winter months when solar radiation capture is small. Experimental validations have also been performed to access the accuracy of the developed relations and model.展开更多
Solar cookers are a good option in developing countries with high solar potential for environmentally friendly cooking and reduced pressure on forests. However, they are still affected by the intermittency of the sun....Solar cookers are a good option in developing countries with high solar potential for environmentally friendly cooking and reduced pressure on forests. However, they are still affected by the intermittency of the sun. In order to overcome this problem, in this work, a box type solar cooker integrated Jatropha oil as a heat storage material is fabricated and experimented with. The design was examined with a maximum stagnation temperature of 157.7°C. The recorded cooking power vanished between 78.4 and 103.6 W, while thermal efficiency varied from 41.26% to 58.78%. The energy transfer cycle test, including charge and discharge revealed that 91.18% of the heat lost through the cooker could be recovered by the heat storage unit and a large amount is restored to the system during cloudiness or a temperature perturbation.展开更多
The objective of this work is to numerically determine the thermal performance of the parabolic cylinder cooker commonly “blazing tube”. These performances were determined by establishing heat balances at the differ...The objective of this work is to numerically determine the thermal performance of the parabolic cylinder cooker commonly “blazing tube”. These performances were determined by establishing heat balances at the different levels of the system. The equations obtained have been discretized;simplifying assumptions have been made to facilitate their resolution. We adopted Gauss Seidel’s method using MATLAB software to solve these equations. The temperatures of the coolant, the glass and the absorber were determined as a function of time and along the tube. The thermal efficiency was also determined. It emerged that the different temperatures evolve linearly as a function of the length of the tube. Yield and temperatures depend on the amount of sunshine.展开更多
A box-type solar cooker with an inclined surface, equipped with a concentration reflector to allow maximum energy to be collected, enabled cooking tests to be carried out in the rainy season. Different thermocouples w...A box-type solar cooker with an inclined surface, equipped with a concentration reflector to allow maximum energy to be collected, enabled cooking tests to be carried out in the rainy season. Different thermocouples were implanted on various places of the cooker. The temperature measurements from these sensors were taken every 10 minutes.<span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The tests presented in this article relate to the preparation of eggs and rice. The absorber temperatures during the tests exceeded 100<span style="white-space:nowrap;">°</span>C. The cooking times were between 1</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">h</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">50</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">min and 2</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">h</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">20 min despite the numerous cloudy periods. The cooker made it possible to reach sufficient temperatures for healthy cooking of food. The results obtained for these first tests are satisfactory and very encouraging.</span></span></span>展开更多
<span style="font-family:Verdana;">We studied the temperature distribution and fluid velocity in a box-type solar cooker by using the Finite Element Method (FEM) in Ziguinchor southern of Senegal. Inde...<span style="font-family:Verdana;">We studied the temperature distribution and fluid velocity in a box-type solar cooker by using the Finite Element Method (FEM) in Ziguinchor southern of Senegal. Indeed, this is one of the sunniest countries in the world: more than 3000 hours of sunshine per year with an average temperature of around 30<span style="white-space:nowrap;">˚</span>C. This abundant and exploitable solar energy contributes to the development of more efficient, profitable and clean sources of energy. This will help to satisfy the increasing demand of energy. This numerical model was validated by comparing the numerical results with those of the experiment carried out on a single day. The relative error obtained is below 3%. The model results confirmed the performance of this cooker as its cooking temperature is available for more than seven hours. They have shown that the temperature and internal fluid velocity fields are not homogeneous. The results, although preliminary and encouraging, are a first step towards the complete simulation of a solar cooker integrated into a drying column.</span>展开更多
This work is devoted to an experimental study of metallic pressure cooker insulated with kapok wool, a vegetal biodegradable fiber. Experiments conducted on the cooling of hot water in the equipment revealed very low ...This work is devoted to an experimental study of metallic pressure cooker insulated with kapok wool, a vegetal biodegradable fiber. Experiments conducted on the cooling of hot water in the equipment revealed very low heat losses and a time constant of 60 hours on average. As a result, the equipment makes it possible to finish cooking meals only thanks to the heat stored at the beginning of cooking and keeps cooked dishes warm for long hours. The thermal phase shift of the pressure cooker is around 7?h. Cooking tests conducted on some local dishes revealed about 70% butane gas savings for cooking cowpea and white rice, 38% for cooking fatty rice, 75% for pasta and couscous, and 30% for cooking potato stew. These results show that this technology can contribute to minimizing?energy consumption in the restaurant sector.展开更多
Collecting wood was areal pain in the fore-head. We used to goto the forest to collectwood thirty times or so eachwinter regardless of the snowor wind. We had to get up anhour or so after midnight andafter doing our c...Collecting wood was areal pain in the fore-head. We used to goto the forest to collectwood thirty times or so eachwinter regardless of the snowor wind. We had to get up anhour or so after midnight andafter doing our chores wewould head off to the forest.We didn’t return until dusk,"said Ms.Zhongcujia,aged 52and a resident of Niamu orFish Village,located in JiancaCounty,Malho TibetanAutonomous Prefecture,Qinghai Province,China. FishVillage is nestled on a denud-ed west-facing mountainslope.展开更多
文摘Off-grid solar cooking in the developed and developing regions of the world is becoming one response to climate change that causes wood-fuel shortages and an increase in cost of coal, gas, and electricity production and their transportation. This paper examines a series unloaded temperature and loaded (food) performance metrics for an inclined window solar box cooker (SBC) designed for Mediterranean latitudes (35.31˚N, 24.31˚E). Solar radiation analysis using two different computer software platforms (SunCalc and Autodesk Revit® with insight plug-in software) is used to date and time-stamp the solar box cooker solar input power. Performed sensible heat tests demonstrate that the solar cooker can reach unloaded internal temperatures of 120˚C at a solar irradiance of 192 W, and a first figure of merit of 0.08 to 0.105. Food cooking metrics is performed on: whole eggs-without water, and the following with water;White medium-grain rice, rice pudding, pastitsio #2 pasta and Brown small lentils. The analytical metrics reveals that their required cooking power is 13 to 53 W;cooking energy of 94 to 210 kJ and energy density is 0.2 to 0.6 kJ⋅g−1. Using day and time-stamped computed solar input power the food cooking power efficiency varies between 6% to 8.9% for three whole eggs-without water, and 16% to 35.5% for rice, pasta, and lentils cooked in water. For water-stressed communities in traditional desert and emerging drought regions a mass-based wastewater/product metrics is used to help drive the water efficiency of the solar cooking process.
文摘Recently, Shunde Electric Pressure Cooker Alliance （short for EPCA） successfully made four proposals on revision of the IEC international standard for electric pressure cooker with independent intellectual property rights, namely Elastic Structure Design, Anti-blocking Safety, Pressure Relief Safety and Lid Closing Safety. In the mean time, when participating in the activities related with revision proposals on IEC standard Electric Pressure Cooker, EPCA makes full use of the information and experience gained in these activities, improves and put forward the new-edition Electric Pressure Cooker Alliance Standard （hereafter referred to as Alliance Standard）. This article is an interpretation with this Alliance Standard aiming at bettering the pressure cooker enterprises＇ understanding with this standard, so as to guide the alliance enterprises to highlight the differentiated characteristics and product features in the links like products design, procurement of raw and auxiliary materials, manufacturing and sales, etc., as well as to let industrial peers learn about the characteristics of this standard and the products.
基金the Embassy of France in Burkina Faso,the National Research Fund for Innovation and Development(FONRID)and the International Science Program(ISP)of UPPSALA University for their financial support which allowed the realization of this work.
文摘In this work, a numerical study of heat transfers in a metallic pressure cooker isolated with kapok wool was carried out. This equipment works like a thermos, allowing finishing cooking meals only thanks to the heat stored at the beginning of cooking, which generates energy savings. Cooked meals are also kept hot for long hours. In our previous work, we have highlighted the performances of the pressure cooker when making common dishes in Burkina Faso. Also, the parameters (thickness and density) of the insulating matrix allowing having such performances as well as the influence of the climatic conditions on the pressure cooker operation were analyzed in detail in this present work. The numerical methodology is based on the nodal method and the transfer equations obtained by making an energy balance on each node have been discretized using an implicit scheme with finite differences and resolved by the Gauss algorithm. Numerical results validated experimentally show that the thickness of the kapok wool as well as its density play an important role in the pressure cooker operation. In addition, equipment performances are very little influenced by the weather conditions of the city of Ouagadougou (Burkina Faso).
文摘Mathematical relations are developed to compute optimum inclination angle of booster mirror for horizontally placed cooker (λ) and for optimally inclined cooker (ψ) during all months (selected day) of the year at 30°N latitude for maximizing the reflected component of solar intensity onto the absorber plate of the cooker. A solar radiation model is also developed and used to compute the ratio of various solar intensities on horizontal, inclined and normal surface of the absorber plate for all months at 30°N latitude. These ratios give a clear indication of greater solar radiation availability on the optimally inclined cooker as compared to the horizontally placed cooker for faster cooking especially during winter months when solar radiation capture is small. Experimental validations have also been performed to access the accuracy of the developed relations and model.
文摘Solar cookers are a good option in developing countries with high solar potential for environmentally friendly cooking and reduced pressure on forests. However, they are still affected by the intermittency of the sun. In order to overcome this problem, in this work, a box type solar cooker integrated Jatropha oil as a heat storage material is fabricated and experimented with. The design was examined with a maximum stagnation temperature of 157.7°C. The recorded cooking power vanished between 78.4 and 103.6 W, while thermal efficiency varied from 41.26% to 58.78%. The energy transfer cycle test, including charge and discharge revealed that 91.18% of the heat lost through the cooker could be recovered by the heat storage unit and a large amount is restored to the system during cloudiness or a temperature perturbation.
文摘The objective of this work is to numerically determine the thermal performance of the parabolic cylinder cooker commonly “blazing tube”. These performances were determined by establishing heat balances at the different levels of the system. The equations obtained have been discretized;simplifying assumptions have been made to facilitate their resolution. We adopted Gauss Seidel’s method using MATLAB software to solve these equations. The temperatures of the coolant, the glass and the absorber were determined as a function of time and along the tube. The thermal efficiency was also determined. It emerged that the different temperatures evolve linearly as a function of the length of the tube. Yield and temperatures depend on the amount of sunshine.
文摘A box-type solar cooker with an inclined surface, equipped with a concentration reflector to allow maximum energy to be collected, enabled cooking tests to be carried out in the rainy season. Different thermocouples were implanted on various places of the cooker. The temperature measurements from these sensors were taken every 10 minutes.<span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The tests presented in this article relate to the preparation of eggs and rice. The absorber temperatures during the tests exceeded 100<span style="white-space:nowrap;">°</span>C. The cooking times were between 1</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">h</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">50</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">min and 2</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">h</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">20 min despite the numerous cloudy periods. The cooker made it possible to reach sufficient temperatures for healthy cooking of food. The results obtained for these first tests are satisfactory and very encouraging.</span></span></span>
文摘<span style="font-family:Verdana;">We studied the temperature distribution and fluid velocity in a box-type solar cooker by using the Finite Element Method (FEM) in Ziguinchor southern of Senegal. Indeed, this is one of the sunniest countries in the world: more than 3000 hours of sunshine per year with an average temperature of around 30<span style="white-space:nowrap;">˚</span>C. This abundant and exploitable solar energy contributes to the development of more efficient, profitable and clean sources of energy. This will help to satisfy the increasing demand of energy. This numerical model was validated by comparing the numerical results with those of the experiment carried out on a single day. The relative error obtained is below 3%. The model results confirmed the performance of this cooker as its cooking temperature is available for more than seven hours. They have shown that the temperature and internal fluid velocity fields are not homogeneous. The results, although preliminary and encouraging, are a first step towards the complete simulation of a solar cooker integrated into a drying column.</span>
基金the National Research Fund for Innovation and Development(FONRID)the International Science Program(ISP)for their financial support.
文摘This work is devoted to an experimental study of metallic pressure cooker insulated with kapok wool, a vegetal biodegradable fiber. Experiments conducted on the cooling of hot water in the equipment revealed very low heat losses and a time constant of 60 hours on average. As a result, the equipment makes it possible to finish cooking meals only thanks to the heat stored at the beginning of cooking and keeps cooked dishes warm for long hours. The thermal phase shift of the pressure cooker is around 7?h. Cooking tests conducted on some local dishes revealed about 70% butane gas savings for cooking cowpea and white rice, 38% for cooking fatty rice, 75% for pasta and couscous, and 30% for cooking potato stew. These results show that this technology can contribute to minimizing?energy consumption in the restaurant sector.
文摘Collecting wood was areal pain in the fore-head. We used to goto the forest to collectwood thirty times or so eachwinter regardless of the snowor wind. We had to get up anhour or so after midnight andafter doing our chores wewould head off to the forest.We didn’t return until dusk,"said Ms.Zhongcujia,aged 52and a resident of Niamu orFish Village,located in JiancaCounty,Malho TibetanAutonomous Prefecture,Qinghai Province,China. FishVillage is nestled on a denud-ed west-facing mountainslope.
