Design, development and testing of a large-size solar cooker for animal feed

A large-size solar cooker for animal feed has been designed, developed and tested. The cooker employs locally available materials of low cost, e.g. pearl-millet husk and horse excreata. The commercial materials required for its fabrication are plain glass, mild steel angle and sheet, wood and aluminium sheet cooking utensils. The solar cooker is capable of boiling 10 kg of animal feed, sufficient for five cattle per day. The efficiency of the solar cooker is 21·8%. The cost of the cooker is only Rs 1200, which can be recovered in 0·45-1·36 years depending upon the fuel it replaces. The short payback periods suggest that the use of the solar cooker is economic. The use of the cooker will save a lot of firewood, cowdung cake and agricultural waste which are presently used for the boiling of animal feed.     

Performance and testing of large-size solar water heater cum solar cooker

The performance of a novel device has been tested. The device can be used as a collector cum storage type solar water heater during the winter, and, with minor adjustments, it can be used as a hot-box solar cooker. The device can provide hot water at 50–60°C in the evening, which can be maintained at 40–45°C until the following morning. It can also be used for cooking food for about 40 people. The efficiencies of the device as a solar water heater and as a solar cooker have been found to be 67.7% and 29.8%, respectively. The payback period varies between 1.64 to 5.90 years depending on the fuel it replaces. The payback periods are of increasing length with respect to the fuels firewood, coal, electricity, LPG and kerosene.     

Experimental investigation of energy and exergy efficiency of masonry-type solar cooker for animal feed

The performance of a masonry animal feed solar cooker was evaluated in terms of energy and exergy. It is a low-cost cooker made of cement, bricks, glass covers and a mild steel absorber plate. The energy and exergy efficiencies of the animal feed solar cooker were experimentally evaluated. The energy output of this cooker ranges from 1.89 to 49.4 kJ, whereas the exergy output ranges from 0.11 to 2.72 kJ during the same time interval. The energy efficiency of the cooker varies between 1.12% and 29.78%, while the exergy efficiency varies between 0.07% and 1.52 % during the same period.     

Performance and testing of an improved solar water heater cum steam cooker

The paper reports performance and testing of an improved solar water heater cum steam cooker. The efficiency of the system as a solar water heater is 51.5 per cent and as a solar steam cooker is 16.1 per cent.     

Design and testing of Sudanese solar box cooker

This study aimed at developing a solar box cooker to be used in Sudan. The cooker was designed and fabricated in the workshop of Centre for Energy Studies, Indian Institute of Technology (IIT), Delhi. A series of tests were carried out during nine days to determine the two factors of merits F1 and F2 in order to make comparison of the cooker against the other Indian designs. The results obtained verified acceptability of the cooker and found successful.     

Techno-economic evaluation of masonry type animal feed solar cooker in rural areas of an Indian state Rajasthan

Utilisation of animal draft power in agricultural operation and milk production is highly dependent on the feed and fodder. Properly cooked feed is digestive in nature and enhance milk production. Solar energy is promising option for slow cooking. Keeping this in view a masonry animal feed solar cooker (AFSC) was developed. It helps in the number of ways to improve the living standard of rural farmers and also reduce the CO₂ emission by replacing conventional fossil fuel. The AFSC can replace the 100 per cent biomass and save about 424.80 kg of CO₂ on annual basis and save about 24 INR per day. Usually women prepare animal feed in rural areas, hence cooking with AFSC save time and this time can be spear to take care of her family or in agricultural operation. This paper presents fuel replacement and reduction of carbon dioxide on annual basis and economic evaluation of AFSC.     

Performance study of solar cooker with modified utensil

A performance study of the box-type solar cooker was made with special emphasis on the shape of lid of the utensils used in a solar cooker. The study revealed that the performance of a solar cooker can be improved if a utensil with a concave shape lid is used instead of a plain lid, generally provided with the solar cooker. The stagnation temperature for a utensil having a concave lid was about 2–7% more than the utensil with a normal lid. The time required for heating the water up to the same temperature in both the utensils was reduced by about 1–13% when a concave shape lid was used.     

Performance analysis of a solar cooker in Turkey

A box‐type solar cooker is designed and its thermal performance is analysed experimentally. The cooker tracks the sun in two axes, altitude and sun azimuth, by hand control for hourly periods. The experimental results show that the tested cooker may be assumed suitable in some cooking processes for specific country conditions. Copyright © 2002 John Wiley & Sons, Ltd.     

Design,development and testing of a novel non-tracking solar cooker

A novel solar cooker that does not require any tracking, has been designed, fabricated and tested and its performance has been compared with the hot-box solar cooker. The performance of the novel solar cooker is almost similar with the hot-box solar cooker though it is kept fixed while the hot box is tracked towards the sun every hour. The overall efficiency of the novel solar cooker has been found to be 29·5%. The payback period varies between 1·30 and 3·29 years depending upon the fuel it replaces. The payback periods are in the increasing order with respect to fuels such as firewood, coal, electricity, kerosene and LPG. The short payback period shows that the use of the novel non-tracking solar cooker is economical. © 1998 John Wiley & Sons, Ltd.     

Performance studies of a large size nontracking solar cooker

A large size nontracking solar cooker has been designed, fabricated and tested. The cooker is based on the hot box principle. The cooker has been tested extensively and its performance has been compared with a solar oven, a hot box solar cooker and a solar cooker (tilted absorber). The stagnation temperatures are in increasing order for the hot box solar cooker, the solar cooker (tilted absorber), the large size nontracking solar cooker and the solar oven. The performance of this solar cooker is comparable with that of a solar oven. The former is not tracked towards sun while the latter is tracked every 30 min. The efficiency of a large size nontracking solar cooker is 24.9%. The energy saved by this new solar cooker has also been calculated and its payback period has been computed by considering interest, maintenance and inflation in fuel prices and maintenance cost. The payback periods are 1.10–3.63 years depending on which fuel it replaces. Relatively short payback periods show that the use of the cooker is economical, and it is easy to operate since no tracking is required.     

A solar cooker for developing countries

A durable solar cooker designed specifically with a view to fabrication in centralized workshops in developing countries is described. The mirror system comprises twelve identical 29.3-cm diameter concave glass mirrors mounted in a frame in a two-axis azimuthal mounting. By using an asymmetrical mirror system and positioning the horizontal axis of rotation at the center of curvature of the image field, all reflected radiation falls on the bottom—and not on the sides—of the cooking pot. Over 500 watts are delivered in bright sunlight. Except for the mirrors, the construction is entirely of iron and the total material cost (including mirrors) is under $8.     

Parameters for a solar cooker program

Cooking with fossil fuels causes health problems and ecological damage in the developing countries. Replacing these fuels with a solar cookers requires low cost materials, production facilities, funds for financing, government cooperation and a marketing program to develop field acceptance. The solar cooker must be high quality, affordable, user friendly, light weight, rugged, stackable and a family size.     

Design optimization of solar cooker

Various designs of solar cookers have been theoretically investigated with a view to optimize their performance. Starting from a conventional box type cooker, various combinations of booster mirrors have been studied to arrive at a final design, aimed at providing a cooker, which can be fixed on a south facing window (for countries of northern hemisphere, mainly situated near the tropic of Cancer). This cooker, with a rear window opening, may provide higher cooking temperature for a fairly large duration of the day. Two or three changes in positions of the side booster mirrors, without moving the cooker as a whole has been proposed. The new design has been experimentally implemented and compared with a conventional box type solar cooker. Besides the convenience of a rear window opening, the cooker provides temperatures sufficiently high to enable cooking two meals a day.     

A parabolic solar cooker with automatic two axes sun tracking system

A parabolic solar cooker with automatic two axes sun tracking system was designed, constructed, operated and tested to overcome the need for frequent tracking and standing in the sun, facing all concentrating solar cookers with manual tracking, and a programmable logic controller was used to control the motion of the solar cooker. The results of the continuous test – performed for three days from 8:30 h to 16:30 h in the year 2008 – showed that the water temperature inside the cooker’s tube reached 90 °C in typical summer days, when the maximum registered ambient temperature was 36 °C. It was also noticed that the water temperature increases when the ambient temperature gets higher or when the solar intensity is abundant. This is in favor of utilizing this cooker in many developing countries, which are characterized by high solar insulations and high temperatures. Besides cooking, the proposed cooker could be utilized for warming food, drinks as well as to pasteurize water or milk.     

Experimental testing of a box-type solar cooker using the standard procedure of cooking power

A box-type solar cooker with one (Model I) or four (Model II) cooking pots was constructed and tested under Tanta prevailing weather conditions. Experiments were performed during July 2002 using the cooker with or without load. The obtained results were employed to calculate the two figures of merit, F₁ and F₂, as well as the utilization efficiency η_u and the specific t_s and characteristic t_c boiling times. The obtained values of F₁ indicate that the cooker can be used twice a day for consecutive cooking. F₂ was found to increase almost linearly with the mass of the cooking fluid M_f. The cooker is able to boil 1 kg of water in 15 min when its aperture area equals 1 m². Furthermore, experiments also considered the requirements for the international standard test procedure for solar cookers. The cooking power P was correlated with the temperature difference ΔT between the cooking fluid and the ambient air. Linear correlations between P and ΔT had correlation coefficients higher than 0.90 satisfying the standard. The obtained values of the initial cooking power, heat loss coefficient and the cooking power at a temperature difference of 50 °C agree well with those obtained for small solar cookers. The present cooker is able to cook most kinds of food with an overall utilization efficiency of 26.7%.     

Efficient orientation impacts of box-type solar cooker on the cooker performance

The addition of a plane reflector to a box-type solar cooker increases the obtained cooker temperature and this depends upon the efficient orientation of the cooker. In order to find out the effect of the cooker orientation on its performance, the present analysis is carried out. A method is outlined to find out a reflector performance factor and an orientation factor that depend upon the elevation angle of the sun, the solar surface azimuth angle and the reflector tilt angle. The analysis is applied to a cooker placed at Aden (Yemen). The results indicate that with proper cooker orientation the improvement in the performance of the cooker due to the reflector reached during winter is more than 100% at lower elevation angles and is more than 60% at higher elevation angles. It is concluded that with the help of the analysis the optimum position for any place, for any day of the year and for any specific time of the day can be found.     

Parametric model of solar cooker performance

This paper presents a model for prediction of the cooking power of a solar cooker based on three controlled parameters (solar intercept area, overall heat loss coefficient, and absorber plate thermal conductivity) and three uncontrolled variables (insolation, temperature difference, and load distribution). The model basis is a fundamental energy balance equation. Coefficients for each term in the model were determined by regression analysis of experimental data. The model was validated for commercially available solar cookers of both the box and concentrating types. The valid range of model application includes most of the feasible design space for family-sized solar cookers. The model can be used to estimate the cooking capacity of existing box type and concentrating type solar cookers. It can also be used to find the combinations of intercept area and heat loss coefficient required to cook a given quantity of food in a given climate.     

Performance prediction of two models of solar water heaters using a thermal trap

The performance of a built-in storage type of water heater can be improved using the principle of the thermal trap. In the following article, we have proposed two designs of solar water heater with a thermal trap and studied their performance for different duty cycles. A comparison is made with a water heater without a thermal trap. We have found that the proposed designs are nearly as good as the heater without a thermal trap but having a night insulating cover to decrease energy loss for the no-sunshine period.     

Exergy analysis of the solar cylindrical-parabolic cooker

For the first time the simple solar parabolic cooker (SPC), of the cylindrical trough shape, is analysed from the exergy viewpoint. The paper presents the methodology of detailed exergy analysis of the SPC, the distribution of the exergy losses, and, on the example of the cooker surfaces, explains the general problem of how the exergy loss on any radiating surface, should be determined, if the surface absorbs many radiation fluxes of different temperatures. An imagined surface was used in the considerations to close the system of the cooker surfaces. It was shown that optimization is needed, to increase the energy and exergy efficiencies of the cooker.Equations for heat transfer between the three surfaces: cooking pot, reflector and imagined surface making up the system, were derived. The model allowed for theoretical estimation of the energy and exergy losses: unabsorbed insolation, convective and radiative heat transfer to the ambient, and additionally, for the exergy losses: the radiative irreversibilities on the surfaces, and the irreversibility of the useful heat transferred to the water.The exergy efficiency of the SPC, was found to be relatively very low (1%), and to be about 10 times smaller than the respective energy efficiency which is in agreement with experimental data from the literature. The influence of the input parameters (geometrical configuration, emissivities of the surfaces, heat transfer coefficients and temperatures of water and ambience) was determined on the output parameters, the distribution of the energy and exergy losses and the respective efficiencies.     

太阳灶性能测试国际标准简介

〔第三届国际太阳灶学术会议于1997年1月6日至10日在印度哥印拜陀举行,会议提出了太阳灶测试和性能评估的国际标准。之后,美国农业部农业研究中心的科学家P.A.范克(Funk)利用实验数据对该标准进行了评估,认为该标准不仅易于使用,而且所提供的数据可很好的预测太阳灶的热性能。详细报道可见SolarEnergy(Vo1.68,No.1,2000)。—编译者〕