Cooker Performance Research Articles

Numerical Modeling and Experimental Testing of a Solar Grill

A detailed study of a solar cooker used for meat grilling was performed. Experiments were undertaken to test the effects of several parameters on the cooker performance. A mathematical model for the solar grill was developed. Heat balance equations were solved using the fourth-order Runge-Kutta technique. It was concluded that an air-tight oven with double glazing and maximum meat charge will give the best performance and highest efficiency for the solar grill.

Parametric study of a box-type solar cooker

This paper presents the theoretical analysis and performance investigation of a single, as well as double, glazed box-type solar cooker with or without reflectors. The mathematical model is developed using the heat balance analysis of the various components of the cooker. In the present analysis, the properties of cooking materials and the value of the overall heat loss coefficient are allowed to vary as a function of the absorber plate and food temperatures. The obtained thermal equations are solved on the computer using a stepwise solution which enabled the temperatures of the various elements of the cooker to be predicted. An optimization parametric study has been performed using several important parameters of the cooker. The effect of those parameters on the cooker performance was studied. The results of the theoretical investigation are compared with the experimental results available. The experimental results conform reasonably with the predicted values.

Mathematical model of the thermal performance of box-type solar cookers

A mathematical model of the heat transfer processes involved with a box-type solar cooker, containing food, was developed. Solar radiation, including that from a flat reflector, enters the box and heat transfer within and out of the box was considered. Using small increments of time, the computer model finds the temperature of the air, food, interior walls and top cover as the solar flux varies throughout the cooking period. Sample results are presented, giving the food temperature as affected by latitude, month, wind, clouds, mass of food, thermal resistance of the box walls and adjustment of the box while cooking.

A model of an improved low cost-indoor-solar-cooker in Tanta

A simple flat-plate solar cooker with focusing plane mirrors and energy storage capabilities has been designed and constructed by the locally available materials in Tanta University. The temperature distributions during the test periods through the absorbing plate, the glass covers, the cooking pot, the cooking fluid, the storage medium and the ambient were determined. The diurnal variations of incident global solar insolation were presented. The utilization of sensible heat storage medium such as sand was investigated thoroughly. A jacket of sand ( 1 2 - cm thick) around the cooking pot has improved the cooker performance tremendously. The temperature differences between the heat source and the heat sink during the test time were determined and the results were discussed. Six hour per day of cooking time has been recorded. Approximately three hours per day of indoor cooking has been achieved. An overall energy conversion efficiency up to 28.4% has been obtained which is considered the best among other solar cookers in the literature. The possibility of using a phase change material as a storage medium to obtain longer cooking periods was studied. A thin layer of the salt hydrate Ba(OH) 2 ·8H 2 O as a jacket around the cooking pot was suggested. The cost of the whole cooker is not more than $15 including the pot and the labour expenses. A step for commercial production of two-pots-solar-cooker has been taken. Extensive efforts are required to diffuse this technology into the villages of the people who could benefit from it.

A new solar cooker design

This paper deals with a new box-type solar cooker design with a single reflector at the hood. In this design, the base of the oven acts as the lid, unlike the conventional box-type solar cooker. With the introduction of this concept of the lid as the base of the oven, we solve the problem of preheating, as faced in the conventional box-type solar cooker. Thus, the performance of conventional box-type solar cookers can be appreciably improved by having the lid at the bottom of the oven and not at the top. It has been observed that, having cooked once, the preheating time for further cooking is greatly reduced as compared to the conventional box type. Hence, cooking twice a day by this cooker becomes easier, unlike cooking by the conventional one.

On prediction of solar cooker performance and cooking in pyrex pots

Results of experiments conducted on the Arafa cookers that featured insulated receivers with Pyrex pots are presented. The utility of an absorption plate is described. A method is outlined whereby the performance curves of solar cooking are transformed into strainght lines. The resulting S -constants are utilized for the prediction of the time-temperature relationships of cookers operating at various levels of insolation for a given charge.

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.

An energy thrifty solar cooler—The mina oven

Abstract A commercial version of the Telkes oven was modified to feature a vapor-tight pot that was thermally bonded to a single glazed collector plate. The resulting spillproof Mina ovens of 0·18 m2 aperture area were tested along with a similarly sized sunspot oven in heating water and oil, and in cooking. For Mina ovens a cooking time for meat dishes of about 70 min was recorded for a charge of 400g of meat and rice. The characteristic water boiling time of about 24 min·m2 kg−1 was achieved by the Mina ovens which was a fraction of that of the Telkes oven. Various criteria were proposed for the assessment of performance of cookers. The overall utilization efficiency as well as the characteristic boiling time were observed to be particularly useful. The developed Mina ovens with an overall utilization efficiency up to 27% ranked the best in performance among other cookers in the literature.

Temperature-decay curves in the box type solar cooker : Abou-Hussein, M.S. M., United Nations Conference on New Sources of Energy, Rome, 1961, 8 p.

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.