Thermal Performance Of Solar Cooker Research Articles

Experimental thermal performance studies on solar hot box cooker with different absorber coating materials

Hot box-type solar cookers can be a promising option for meeting the challenges of clean cooking fuel for communities in developing countries. One of the major components of hot box solar cookers is the absorber tray, which is responsible for converting solar radiation into useful thermal energy for a heating load. For improving the efficiency of the hot box solar cooker it is important to enhance the absorption. The present work focuses on enhancing the thermal performance of solar cookers using different absorber coating materials on the absorber tray. Comparative studies on box-type solar cookers have been done for black matt paint and mixed material paints. Five types of mixed material paints were prepared by mixing CuO, TiO2, activated carbon, Tungsten, and mica with black paint. These prepared mixed material paints were examined in reference to the black matt paint on the identical sections of box type solar cooker. The experiments were conducted with different coating materials with water load and without load conditions. During the experiments, the surface temperature difference without load was found to be in the range of1°C to 14 °C for different materials. With water load conditions, the hot water temperature difference was observed to be about 1 °C to 7 °C for different coatings.

Thermal Performance of Solar Cooker Based on Evacuated Tube Collector and PCM Storage Unit

In this experimental set up, solar cooker with thermal storage unit was connected to evacuated tube collector through connecting pipes via a low flow rate pump. The design of solar cooker was such that the following fluid transfers its heat to PCM and cooking vessel simultaneously. Commercial grade acetanilide was used as latent heat storage material in the solar cooker. Cooking experiments were conducted during noon and evening with different loads and PCM storage processes were carried out simultaneously. The result include that cooking lunch for a family is possible simultaneously with heat storage along the day. Closing gate valves afterward allows cooking the dinner with the retained heat up to late evening. This expands the applicability of solar cooking and sustains the possibility of all the day around cooking using solar energy with a low inventory cost.

Thermal performance of solar cooker with special cover glass of low-e antimony doped indium oxide (IAO) coating

Indium, cadmium and tin based transparent conducting oxide (TCO) films have low thermal emissivity values and these are suitable for energy efficient applications where controlling of thermal effect is an important factor. Among these films antimony doped indium oxide (IAO) coated glass has been explored to have resistivity ∼2×10−2Ωcm. The film is homogeneous and good adherence to glass even in large dimensions [500mm×500mm]. This film possesses emissivity ∼0.63 and it has been taken as the standard for the calculation of solar factor (gi) and absorbed solar energy reradiated and convected indoors (Ei) of transparent conducting oxide (TCO) films of 32 types. As calculated, the gi and Ei values of a TCO films are in the ranges 0.77–0.02 and 2.9–59Wm−2 respectively. Attempt has been made to use the IAO coated glass to improve glazing system in solar cooker with the principle that lowering of gi and Ei values would correspond to significant increase of heat insulation property. The thermal performance of solar cooker box having a cover of single layer low-e IAO coated glass was compared with the solar cooker box having a cover of uncoated double glaze soda lime silicate (SLS) glass initially and finally with the same solar cooker box with evacuated glazed cover maintaining vacuum (10−3atm) in the glazing system. Thermal performance of the solar cookers at ambient condition differs due to the variation of heat flow through glass cover with different glazing systems. The performance was promising for the solar cooker box with the cover of single glazed low-e IAO coated glass. The added advantages for domestic usage are low cost of production, relatively light weight and high mechanical durability along with relatively high thermal output.

Eficiencia de diferentes modelos de cocinas solares evaluadas bajo condiciones ambientales de la costa caribe colombiana

An important part of the population does not have access to public services such as gas and electricity. their main source of energy is coal and wood, particularly for cooking, with negative impacts on environment. It is possible to explore alternatives tomitigate these impacts, such as the use of solar energy. The use of low power solar cookers by poor people is widespread, but from the technical point of view, their thermal behavior is not known. This paper presents a proposal to how to perform the tests based on international protocols evaluation of the thermal performance of solar cookers and submit the results of the linear fit of two variables that arise from the energy balance. First, we selected for evaluation many kinds of solar cookers, takinginto consideration important aspects such as building materials of their components, such as cardboard and aluminum. Results from the data analysis show the difference in thermal behavior between different prototypes and models analyzed. The best thermal performance in our analysis is presented by fun panel cooker.

Experimental comparison of different heat transfer fluid for thermal performance of a solar cooker based on evacuated tube collector

A comparison of thermal performance of solar cooker with two different heat transfer fluid (HTF) and effect of gate valve on discharge process of phase change material (PCM) had been investigated experimentally. In this experimental setup, solar cooker with inbuilt thermal storage unit was connected to evacuated tube collector through connecting pipes. The available solar heat in the collector was transferred to the solar cooker by natural circulation (thermosiphon) of HTF. The water and thermal oil (engine oil) were used separately as HTF to compare the thermal performance of solar cooker. Commercial grade acetanilide was used as thermal storage material in the solar cooker. The PCM discharging process was studied, firstly when both gate valves were open and secondly when both gate valves were closed during discharging process. Then, cooking was carried out using thermal oil as HTF, and both gate valves were closed during discharging of PCM. It was found that with water as HTF, the temperature of PCM at 18:00 h was 10.7 °C higher when both valves were closed as compared to the case when both valves were opened, whereas it was 13.1 °C in case of thermal oil as HTF. Using thermal oil as HTF, quantity of average energy stored by PCM was increased by an amount of 18.88 % as compared to water as HTF.

An Investigation into the Effects of Box Geometries on the Thermal Performance of Solar Cookers

The effect of box geometry, such as cylindrical and rectangular, on the performance of solar cookers has not been investigated. In this study, two different model box type solar cookers, which are in rectangular and cylindrical geometries, were constructed using the same material and were tested to investigate the effects of box geometries on the cooker performance. The experimental studies were conducted under the same operating conditions. The obtained results from the experiments were used to calculate the thermal efficiency and specific and characteristic boiling times. These parameters of the cookers were determined for 0.5, 1, and 1.5 kg of fresh water. It is observed that the cylindrical model has higher temperatures than the rectangular model under the same operating conditions. The thermal efficiency increased from 12.7 to 36.98% for cylindrical and 9.85 to 28.25% for rectangular model, when the quantity of water was increased from 0.5 to 1.5 kg; similarly, the characteristic boiling time was decreased from 39.56 to 14.35 for the cylindrical and 43.74 to 15.77 (min m−2 kg−1) for the rectangular model, respectively. The cylindrical model provided high thermal performance, which is indicated by high thermal efficiency and low characteristic boiling time, in comparison with the rectangular model.

Thermal performance parameters estimation of hot box type solar cooker by using artificial neural network

Work to date has shown that Artificial Neural Network (ANN) has not been used for predicting thermal performance parameters of a solar cooker. The objective of this study is to predict thermal performance parameters such as absorber plate, enclosure air and pot water temperatures of the experimentally investigated box type solar cooker by using the ANN. Data set is obtained from the box type solar cooker which was tested under various experimental conditions. A feed-forward neural network based on back propagation algorithm was developed to predict the thermal performance of solar cooker with and without reflector. Mathematical formulations derived from the ANN model are presented for each predicting temperatures. The experimental data set consists of 126 values. These were divided into two groups, of which the 96 values were used for training/learning of the network and the rest of the data (30 values) for testing/validation of the network performance. The performance of the ANN predictions was evaluated by comparing the prediction results with the experimental results. The results showed a good regression analysis with the correlation coefficients in the range of 0.9950–0.9987 and mean relative errors (MREs) in the range of 3.92516–7.040% for the test data set. The regression coefficients indicated that the ANN model can successfully be used for the prediction of the thermal performance parameters of a box type solar cooker with a high degree of accuracy.

Estimation of design parameters for thermal performance evaluation of box-type solar cooker

The paper presents a simple test procedure for determination of design parameters to predict the thermal performance of a box-type solar cooker. A series of out-door experiments were performed on the double-glazed solar cooker of aperture area 0.245 m 2 with a fibre body to obtain two figures of merit, F 1 and F 2. The necessary design parameters—optical efficiency, F′ η o and heat capacity, (MC)′ of the cooker are calculated using the linear regression analysis of experimental F 2 data for different load of water. Based on the experimental results, a correlation for F 2 as a function of quantity of water (load) is proposed. The close agreement between experimental and calculated F 2 indicates the validity of the correlation. The proposed procedure is then applied to predict the heating characteristic curves of the solar cooker for different load of water. The predicted heating characteristic curves are validated by comparing with the experimental data from a series of cooker testing experiments. The results of present study reveal that F′ η o and (MC)′ are the critical design parameters required for the prediction of thermal performance of the solar cooker.

Thermal performance of a solar cooker based on an evacuated tube solar collector with a PCM storage unit

The thermal performance of a prototype solar cooker based on an evacuated tube solar collector with phase change material (PCM) storage unit is investigated. The design has separate parts for energy collection and cooking coupled by a PCM storage unit. Solar energy is stored in the PCM storage unit during sunshine hours and is utilized for cooking in late evening/night time. Commercial grade erythritol was used as a latent heat storage material. Noon and evening cooking experiments were conducted with different loads and loading times. Cooking experiments and PCM storage processes were carried out simultaneously. It was observed that noon cooking did not affect the evening cooking, and evening cooking using PCM heat storage was found to be faster than noon cooking. The cooker performance under a variety of operating and climatic conditions was studied at Mie, Japan.

Evaluation of solar cooker thermal performance using different insulating materials

This paper summarizes very briefly the thermal performance of solar cookers with four different insulations readily available in rural areas. A comparison of each one of these is made with the performance of glass wool. This experiment is performed to minimize the cost of the cooker with a view to enhance its widespread application in the rural Indian environment.