Amount Of Heat Loss Research Articles

Technical aesthetics of stained glass panels for the modern architectural paradigm of Southern Russia

The construction sector consumes more than half of the energy generated in Russia. Therefore, practical application of energy-efficient and aesthetic construction products is highly required. The article aims at looking into the way to enhance characteristics of the double-glazed window, which is an energy-saving product in a building that regulates the amount of light energy indoors and affects the amount of heat loss in winter. Until now, this function has been the main one for double-glazed windows. Secondary, but no less important, is the aesthetic appearance of the double-glazed window. The study is based on the experimental data obtained through the ramp-hold programme according to COE 96 as well as through the comprehensive analysis of six glass types manufactured by Oceanside Glass & Tile®. As a result, the study discusses characteristics of stained glass that can be used for Tiffany technique inserts in a window opening. Such stained glass panels throughout the entire historical path have demonstrated sublime beauty and lightness, both indoors and outdoors. Modern technologies allow us to take the art of stained glass and its adaptation in modern double-glazed windows to a new level. Finally, special attention is paid to the aesthetics of stained glass panels for the modern architectural paradigm of Southern Russia.

Heat rejection effect study on large-scale sodium test facility STELLA-2

The STELLA-2 facility is a large-scale sodium test facility to support the development of PGSFR and is accumulating extensive experiment data. The experiment campaigns of STELLA-2 are mostly planned to be transient and therefore it is very challenging to analyze and quantify the amount of heat loss. In this study, a deliberate heat rejection at arbitrary points to consider the heat loss is discussed and the comparison result between the experiment and code calculation is described. The code calculation with heat loss indicates improvement in prediction and it was verified that the behavior of heat transfer in IHTS loops was mostly influenced by the heat loss. For further study, the heat loss effect on other experiments will be evaluated in the coming years.

The dual role of manganese oxide simultaneously in enhancing bioactivity and magnetic properties of glass ceramics used in cancer treatment

Replacing conventional cancer treatment methods like chemotherapy, which has many adverse effects, with new methods such as magnetic fluid hyperthermia, is one of the significant challenges. In this study, the effect of adding different MnO2 wt% to 20SiO2‐50FeO‐15CaO‐15Na2O glass-ceramic was studied. Maghemite, hematite, jacobsite and sodium calcium silicate phases were crystallized in the glass ceramics. Absorption bands of maghemite with a completely regular crystal structure were observed in the range of 472 and 560 cm−1 wavenumbers. The investigation of the magnetic properties also showed that the saturation magnetization of the samples increased from 21.5 emu/g to 30.80 emu/g by increasing the MnO2 from 0 to 15 wt%. The highest amount of heat loss under alternating magnetic field was also measured for the same sample and its value was 18 °C. Hydroxyapatite with cauliflower morphology was also observed in the phase and structural investigations of the samples immersed in the simulated body fluid.

Thermal design of insulation on the outside of the cavity for a Trombe wall with phase change materials

A Trombe wall with a phase change material (TW-PCM) is a practical and low-carbon passive solar heating method. However, the heat efficiency is not high due to the large amount of heat loss at night. Insulation on the outside of the cavity is a suitable solution, but the design method has not been obtained, which hinders the realization of zero energy buildings. In the present study, we analyzed the thermal performance of a TW-PCM with insulation on the outside of the cavity at nighttime to develop the design approach. A mathematical model was established and validated based on experiments. This model was used to analyze the heat efficiency in different outdoor climates for a TW-PCM with insulation on the outside of the cavity. As well, the solar heating fraction (SHF) was analyzed. The results indicated that insulation on the outside of the cavity could significantly improve the thermal performance due to the reduced heat loss during the nighttime. The recommended additional thermal resistance due to the insulation on the outside of the cavity was negatively correlated with the average outdoor air temperature in January based on the analysis of various climates in China. The thermal resistance of the closed air cavity, formed by the TW-PCM and the insulation component, at the same wall emissivity was similar under the recommended additional thermal resistance in different outdoor climates. The SHF was improved significantly for the TW-PCM buildings with insulation on the outside of the cavity and it had a linear relationship with the solar heating load ratio (SLR).

Thermal analysis of the window-wall interface for renovation of historical buildings

Due to the long time since their construction, some old buildings have experienced a decline in performance and do not meet contemporary requirements. Retrofitting methods, as opposed to demolition and reconstruction, are considered a more cost-effective and energy-efficient approach, particularly applicable to historical buildings with conservation significance. Exterior windows account for a significant amount of heat loss within the building envelope, but it is a challenge to improve its performance while retaining the historical appearance of the building when retrofitting. In this paper, a new design of the window-wall interface structure was proposed, which facilitated the incorporation of additional thermal insulation materials and mitigated the thermal bridge effect at the joint between the window frame and the wall. Comparative analysis with existing window-wall interface structures revealed the superior thermal performance of the proposed structure, with less heat transfer as well as smaller surfaces at risk of condensation. The structure was first implemented in a renovation project in Nanjing, providing an innovative approach for future exterior window renovations of historical buildings.

Keeping cool with poop: Urohidrosis lowers leg surface temperature by up to 6°C in breeding White storks

AbstractStorks (Ciconiidae) are renowned for defecating on their legs when exposed to high temperatures, a phenomenon known as “urohidrosis.” Previous work suggested that this behavior can cool down the blood supply to the legs and thus prevent hyperthermia in captive storks when overheated. However, no study has quantified the magnitude or duration of its evaporative cooling effect in free‐ranging birds. Here, we combine urohidrosis data with thermal imaging and microclimate data to investigate the thermoregulatory significance of urohidrosis in White storks Ciconia ciconia during the breeding season. We show that urohidrosis can reduce leg surface temperature by up to 6.7°C (4.40 ± 1.04°C). Yet its cooling effect was of short duration (lasting no more than 2.5 min) and decreased with time since defecation. Thus, for urohidrosis to significantly contribute to heat dissipation, storks must perform it repeatedly when overheated. Indeed, an individual can perform up to 11 urohidrosis events per hour; our estimates indicate that repeated urohidrosis could represent a significant amount of heat loss during short time span, equivalent to 4% of daily field metabolic rate for an adult stork. Our results point to an absence of differences in the cooling efficiency of urohidrosis between adults and nestlings, probably because all nestlings were recorded during the last phase of the ontogeny of thermoregulation. Besides, during the hottest days, adult storks delivered water to their nestlings, which might allow them to replenish body water reserves to sustain urohidrosis and other heat dissipation behaviors such as panting or gular fluttering. Our results indicate that urohidrosis might buffer the impact of high temperatures in breeding storks, preventing overheating and lethal hyperthermia. Gaining knowledge about behavioral thermoregulation in the heat is therefore crucial to better predict the future persistence and vulnerability of species under different climate warming scenarios.

Calculation specifics in the study of solar greenhouses with thermal energy accumulator in mind

The paper presents a simplified thermal model that allows estimating heat losses taking into account the main parameters: the surface of the greenhouse - a transparent fence, the bottom of the greenhouse - soil and the ratio of the design of greenhouses. A simplified thermal diagram of the greenhouse heat transfer has been compiled and, on the basis of the simplified thermal diagram, heat losses through the transparent enclosure, through the bottom, soil and structural ratios have been determined by calculation. Calculations show that with total solar radiation, 620 W/m2, heat loss through the surface of a transparent fence is 508 W/m2, in percentage terms it is 82%. At the same time, through the bottom (ground) 58 W / m2, in percentage terms they are 9%, the total heat loss is 566 W / m2, in percentage terms they are 91%. To reduce heat loss through the transparent enclosure, it is recommended to use more innovative materials, such as ceramic film with improved thermal insulation properties or low iron glass, extra clear glass, double-layer transparent enclosure, and it is also recommended to enclose one side of the greenhouse with a thermal insulation wall. According to calculations, in order to reduce heat losses through the bottom of the greenhouse, we recommend making a special deepening in the soil, since at large soil depths, a slow spread of soil temperature is observed, which will also lead to the least heat loss. To reduce heat losses through the bottom of the greenhouse, we recommend using thermal energy accumulators in the ground. Estimation of heat losses makes it possible to determine the required amount of heat loss through the surface and bottom of the greenhouse and, based on these calculations, carry out research work to reduce them.

Optimal insulation layer for heated water pipes under technical, economic and carbon emission constraints

Piping systems are a common element of thermal systems in several sectors. They usually have the function to deliver hot fluids for thermal processes and/or final uses, and they might be responsible for a large amount of heat losses, which results in higher primary energy consumption and carbon emissions, if adequate insulation layers are not designed and deployed. Finding the optimal insulation thickness is however not a straightforward process, since several technical, economic and environmental aspects enter into play. The present work investigates different optimisation approaches for determining the optimal thickness of insulation layers in civil and industrial piping systems, by introducing the concept of embodied energy and embodied carbon emissions of the insulation material, together with the economic evaluation of the investment associated with the insulation deployment. Several technical and economic characteristics are considered - e.g., pipe size, insulation materials, primary fuel, operating temperature, climatic conditions, fuel market price, country of origin of the insulation layer, etc. Results shows that the piping geometry, operating conditions and heating system strongly affects the optimal insulation thickness, while the climatic conditions have a little influence, especially for fluid operating temperature above 45 °C. Furthermore, the country of origin of the insulation strongly affects the net carbon savings achievable, due to the different embodied carbon emissions linked to the local energy mix used, and should be considered - e.g. by implementing a certification of origin mechanism, to correctly evaluate the emission reduction potential of the insulation layer deployment.

Effect of Structural Materials on Monopropellant Thruster Propulsion Performance in Micro Scale

This paper reports on the effect of structural materials on heat loss-associated propulsion performance degradation of monopropellant thrusters in the micro scale. In order to address the effect of fabrication materials on heat loss, propellant flow characteristics, and propulsion performance, a conjugate heat transfer numerical study has been conducted considering several practical substrate candidates for microthrusters. The results were analyzed with respect to the thermal diffusivity of the materials, which revealed different propulsion performance characteristics and inner nozzle flow characteristics due to varying amounts of heat loss, depending on the microfabrication materials used and propellant enthalpies. Regardless of propellant enthalpies, however, there was a dramatic degradation in the amount of the thrust produced with respect to thermal diffusivity, particularly in the range of low thermal diffusivity. Glass, among the material types compatible with fabrication processes in regard to microthrusters, exhibited a 4% degradation in thrust performance for the 50 mN class microthruster considered, with the least degradation, while copper, with 7% degradation, exhibited the greatest amount of degradation among the materials considered. With varying chamber pressure and Mach number at the nozzle exit depending on structural materials, the results also indicated the necessity of heat loss consideration in a microthruster design process.

Optimal energy management of CHP‐based microgrid examining different types of district heating networks

AbstractHeat recovery by combined heat and power (CHP) systems to provide heat load reduces the cost of microgrid (MG) energy management. However, heat transfer from CHP systems to consumers is limited due to the heat loss of pipelines. The amount of heat loss varies depending on pipeline material and environmental characteristics. Here, a day‐ahead energy management of CHP‐based microgrid, including various types of CHP systems to supply electrical and thermal loads, is performed. In this regard, the accurate model of heat transfer losses (HTL) through pipelines in the energy management problem is considered. Moreover, the optimal scheduling of different types of MGs in terms of HTL specifications is compared with each other. Evaluating the simulation results, it is inferred that accurate modeling of HTL in the energy management problem has a significant impact on the optimal scheduling and operation cost of MG. To solve the optimization problem, a new enhanced imperialist competitive algorithm (E‐ICA) is examined and validated. The E‐ICA method improves the efficiency of the classical ICA method to prevent getting stuck in local optimums by enhancing exploration and exploitation. The results of the energy management problem show E‐ICA superiority compared to other evolutionary algorithms.

ANALYSIS OF AN ASYMMETRIC TRUNCATED CONCAVE PARABOLIC FIN

An asymmetric truncated concave parabolic fin is analyzed using a two-dimensional analytical method. In this analysis, the variation in the ratio of the top surface temperature to the bottom surface temperature along the fin length is presented. Heat loss from each surface and that from the fin are shown as a function of the convection characteristic number and the fin base height. The ratios of heat loss from each surface to that from the fin are given as a function of the actual fin length. The relationship between the convection characteristic number and the fin base height, as well as that between the actual fin length and the fin base height, are presented for equal amounts of heat loss. One of the results shows that the effect of fin base height variation on heat loss from the fin bottom surface and on heat loss from the fin tip surface is negligible when the actual fin length is fixed.

Energy consumption comparison at various insulation scenarios: Mid-rise residential buildings, Kabul city

An insulating substance is typically used to reduce the amount of heat that enters buildings with air conditioning from the outside. The heat conductivity of this substance is extremely low. In this scenario, having a cost-effective air conditioning system requires using an appropriate insulation material with the right thickness. Up until a certain point, when the material thickness is optimal and will give the maximum overall energy savings, given that the building industry accounts for roughly 40% of worldwide energy consumption and is the greatest producer of greenhouse gas emissions, it is well known that it has a substantial negative influence on the environment too. Therefore, Insulating the outer walls of the building is a recognized method to improve the energy efficiency of buildings in the current setting of ongoing global energy price increases and concern to support global efforts to recover the climate. This study was conducted on a residential building in Kabul city capital of Afghanistan, to study and analyse the insulation materials used to seal the building envelope to calculate how much energy can be saved. Version 4.9 of the HAP program was used to calculate the energy consumption and heating/cooling loads. According to the obtained results, adding insulation to the envelope’s various elements (walls, roofs, windows, etc.) can improve thermal comfort indoors and cut the energy use of the structures under study by between 30 to 40 percent. Especially the amount of heat losses in winter decrease with proper insulation, but due to the low-temperature difference in the summertime, the insulation effect is negligible.

CHOICE OF THE ABSORBING SURFACE CONSTRUCTION OF THE SOLAR COLLECTOR, WHICH IS USED IN THE LIVESTOCK COMPLEX

The possibility of using enclosing structures as an absorbing surface of a solar collector is investigated. The roof of the cowshed of the «Bolshemurashkinsky» breeding plant was selected for analysis. Engineering calculations of technical indicators and simulation of solar radiation on the absorbing surface of the solar collector were carried out to determine the area of shading from the waves of the profiled sheet. The working width of the profiled sheet, wave height, width of the top and base of the wave, and the number of waves in one profiled sheet were considered as technical indicators. These indicators are necessary to determine the area of one wave, the area of all waves contained in the working width of the profiled sheet, the volume of water contained in one wave and in the working area. The obtained results on the shading area were necessary to determine the consumed solar radiation and heat losses. Based on the results of solar radiation simulation and calculations, the grade of profiled sheet was selected, which has the largest working area, thereby reducing the area of the solar collector required for heating water in the cowshed. The data obtained on the amount of incoming solar energy and the amount of heat losses allowed us to determine the efficiency of the solar collector. The conducted analysis showed that the most rational option is the option using HC-44-1000. By calculations performed and simulating the incidence of sunlight on the absorbing surface, it was found that this brand has the largest working area (0.0275 m2) and a volume of water that fits into the working width of the profiled flooring with a length of one meter (27.5 m3).

The Influence of Reservoir Clay Composition on Heavy Oil In Situ Combustion

Thermally enhanced oil recovery methods, such as in situ combustion and steam injection, are generating considerable interest in terms of improving oil reserve exploitation and satisfying oil demand and economic growth. However, the early breakthrough of the in situ combustion front and the significant amount of heat loss associated with steam injection for deeper reservoir applications are the main challenges that require urgent solutions. Further data collection related to the effects of a reservoir’s physical and chemical properties, temperature, and pressure on in situ combustion front propagation and steam injection heat transfer inefficiency would be needed to achieve better reservoir oil recovery. Most studies have focused on the application of catalytic systems and the investigation of minerals’ effects on combustion front stabilization; however, the effect of clay interlayers’ minerals on the performance of in situ combustion is still poorly understood. This paper takes a new look at the role played by the interlayers’ minerals in stabilizing the combustion front using X-ray diffraction (XRD), thermogravimetry (TG), differential scanning calorimetry (DSC) combined with nuclear magnetic resonance (NMR), and combustion tube experiments. The studied samples’ compositions were analyzed by XRD, TG/DSC, and NMR techniques. Meanwhile, the effects of interlayers’ minerals on oil production were screened by combustion tube experiments. The data obtained from this study suggest that clay dispersion within a reservoir would improve oil recovery via in situ combustion, and our study led us to obtain an 80.5% recovery factor. However, the experiments of models with clay interlayers showed less recovery factors, and the model with interlayers led to a 0% recovery factor in the presence of air injection. Meanwhile, the same model in hydrothermal and air injection conditions led to a 13.9% recovery factor. This was due to the hydrothermal effect improving permeability and pore enlargement, which allowed the transfer of heat and matter. Moreover, our study found that clay minerals exhibit excellent catalytic effects on the formation of fuel deposition and the coke oxidation process. This effect was reflected in the significant role played by clay minerals in decreasing the number of heteroatoms by breaking down the C-S, C-N, and C-O bonds and by stimulating the processes of hydrocarbon polymerization during the in situ combustion. Our results add to a growing body of literature related to in situ combustion challenges and underline the importance of a reservoir’s physical parameters in the successful application of in situ combustion.

ANALISA HEAT LOSS PADA PIPA DARI DEMISTER KE TURBIN PADA PEMBANGKIT LISTRIK TENAGA PANAS BUMI LAHENDONG UNIT-2

Geothermal Power Plant in Lahendong is the largest power plant unit with environmentally friendly energy, with geothermal resources in North Sulawesi. At the Geothermal Power Plant in Lahendong unit-2, there are important components used to convert steam into electricity. These components include a demister, turbine, condenser, generator, cooling tower, injection well, and also a heat exchanger. One of the important pipes in the line of the Geothermal Power Plant is the pipe between the demister to the turbine. In the flow of steam in the unit-2 pipe from the demister to the turbine, it may experience heat loss during steam flow. The purpose of this study was to determine the amount of heat loss in the pipe from the demister to the turbine at Geothermal Power Plant Lahendong unit-2. This research uses the Steam Tabie application and Microsoft Excel. In this study, the results of the calculation of heat loss along the pipe from the demister to the turbine at the Lahendong Unit-2 Geothermal Power Plant amounted to 4465699 kJ/s

A New Approach in Heat Transfer Analysis: Reduced-Scale Straight Bars with Massive and Square-Tubular Cross-Sections

This paper reports experimental and theoretical result derived from research on steel structural elements’ fire-protection with intumescent paint. The experimental results were obtained by means of an original testing bench, briefly described below and some basic cases, i.e., horizontally and vertically disposed, massive and square-tubular cross-sectioned, reduced-scale straight bars heated at one end. By means of the thermocouples mounted along the bars, the temperature distribution laws were monitored, depending on the heated end’s nominal temperature. The paper describes an original approach to the temperature distribution evaluation by means of some new parameters, based on the temperature distribution laws experimentally obtained with reduced-scale models. We involved the least-square method (LSM) and the curve-fitting one in order to obtain a more accurate temperature distribution law compared to the experimentally obtained ones. We also introduced some new parameters in order to define the amount of heat loss in a more accurate way. Based on the results obtained, the authors suggest that this approach to the temperature distribution law can be efficiently applied in further thermal analyses, for both 2D and 3D structures. The paper also includes a thorough analysis of “m” variation along the square-tubular-cross-section, reduced-scale straight bars, and similar new approaches are proposed by the authors. The sub-goals of this investigation were (1) to obtain useful correlations between the magnitudes of the massivity ζ=P/A and the parameter “m” along the bar, and (2) to analyze, on reduced-scale models, the heat distribution laws on unprotected and intumescent-paint-protected 2D and 3D steel structures.

Effect of ageing and MAP on quality of striploin from cattle of Holstein-Friesian breed

There have been determined the features of m. longissimus lumborum steaks from young cattle-for-fattening of Holstein-Friesian breed, Polish black-and-white variety. There were measured pH values, basic chemical composition and colour parameters. The meat was subjected to moist-ageing for 12 days and, next, stored in modified atmosphere for the following 10 days. The amount of heat loss in relation to the temperature of thermal processing was determined. Texture parameters were studied instrumentally and organoleptically. The studied muscles from young cattle-for-fattening characterised with proper and similar pH values. The average fat content was 4.37%. The surface colour of the studied dorsal muscle was relatively bright, the average value L*=37.97, and on the cross-section L*=32.97. The average value of the muscle surface's ‘redness’ was a*=18.98, whereas cross-section's a*=20.27. The amounts of heat leakages were rising along with the increase of temperature from 11.24 to 37.14%. Ageing and storing in MAP led to a significant decrease in the amounts of heat leakages. Ageing and storing in MAP had a significant influence on decreasing shear force and on increasing the organoleptic evaluation marks of the m. longissimus lumborum after thermal processing, which shows that the muscle may become culinary meat with features accepted by consumers.

Feasibility of annual dry anaerobic digestion temperature-controlled by solar energy in cold and arid areas.

In cold and arid areas, variations of ambient temperature not only lead to a large amount of heat loss from anaerobic digestion reactors but also greater challenges in the stable production of biogas. Common temperature-controlled methods of biogas production, such as coal combustion, electric heating, biogas combustion and so on, are expensive and high energy-consuming. Openly, solar energy is economical and suitable for stable biogas production. However, no pilot studies have yet shown the feasibility of controlling the temperature of annual biogas production with solar energy in cold and arid areas. This paper first theoretically analyzed the energy balance between evacuated tube solar collectors and anaerobic reactors. Then a biogas production system was developed in Lanzhou City, China, consisting mainly of a 3m3 insulated anaerobic reactor and a solar collector with 30 sticks Φ58×L1800mm evacuated tubes. Annual batch experiments have been carried out to test the feasibility of stable biogas production at a temperature-controlled by solar energy in cold and arid areas. The results show that dry anaerobic digestion with 20% total solid (TS) can start and operate smoothly even under the condition of low solar irradiation for 3-4 consecutive days. The system can run stability by anaerobic digestion at 26±1°C in winter and spring, by mesophilic (37±1°C) and thermophilic (52±1°C) anaerobic digestion in summer and autumn, which implies a highly efficient operation strategy for agricultural and animal husbandry wastes treatment. These theoretical and experimental results provide a scientific basis and engineering reference for the application of biogas production temperature-controlled by solar energy and have important value for the efficient and low-cost anaerobic digestion treatment of agricultural and animal husbandry wastes in cold and arid areas.

Experimental Study on the Effect of Injection Timing on a Dual Fuel Diesel Engine Operated With Biogas Derived From Food Waste

Abstract The present work emphasizes the effects of injection timing on the characteristics of a 5.2-kW powered four-stroke diesel engine using biogas and its heat loss analysis. The biogas is obtained from food waste consisting of methane (CH4)—88.1% and carbon dioxide (CO2)—11.8% as the composition. The biogas (BG) is selected by mass basis ranging from 20% to 60% with 10% increments and is used to operate the engine by dual-fuel mode. The effect of three injection timings such as 25.5 deg (retarded), 27.5 deg (actual), and 29.5 deg (advanced) before top-dead center (bTDC) under dual-mode operation to enhance the properties of the engine is studied, and the results are compared with diesel mode at actual injection timing. Maximum brake thermal efficiency of 30.1% was observed for BG20 operated at 29.5-deg bTDC injection timing (IT). The dual mode operated at the injection timing of 29.5-deg bTDC showed an increase in cylinder pressure compared to diesel by 11.9% at full load conditions, whereas carbon monoxide emission was lower by 5.2% at 29.5-deg bTDC IT than diesel, and nitrogen oxide emission was lower at 25.5 deg bTDC IT than diesel mode by 45%. Besides, at 75% engine load, the least amount of heat losses was observed for BG50 exhibiting effective conversion of fuel energy into equivalent work higher than that of diesel by 2.2%, respectively.

Pengaruh Material Reflektor Terhadap Kinerja Kompor Energi Surya

The use of solar energy in Indonesia is the right choice as an alternative energy for energy needs in industry or to meet daily energy needs in households. To utilize solar energy for cooking purposes, a solar cooker can be used. Factors that affect the performance of this solar cooker in addition to the length of time it shines and the intensity of thermal radiation from the sun are the reflexivity of the collector material, the surface area of ​​the collector, the geometric shape and location of the focal point of the collector, the normal direction of the collector surface to the incoming sunlight, and the amount of heat loss to the surroundings. The materials used as reflectors in the research on this solar cooker are zinc (aluminum and galvanized) AL-Zn and black paint back ground mirror glass. This material is re-glued on top of a ready-made parabolic dish from the market. Then look for the focal point that corresponds to the diameter of the parabola. From the results of the study, it can be concluded that the back ground mirror glass material with black paint is better to use than the AL-Zn zinc plate if it is used as a raw material for the surface material (reflector) of solar cooker. Likewise, the efficiency of the solar oven in terms of the amount of heat that is converted into energy for heating the pot is better for a solar oven than a reflector with black paint back ground mirror glass material. And the efficiency of the solar cooker from the black paint back ground mirror on the first day is 16.4% to 25.7% on the second day, while the efficiency of the solar cooker from the AL-Zn zinc plate on the first day is 16.4% to second day 22.8%. The emissivity of the solar stove with AL-Zn zinc plate reflector on the first day was 0.02906 and on the second day 0.02892, while the emissivity of the solar cooker with black paint back ground mirror reflector on the first day was 0.01812 and the second day was 0 0.02544.