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International Journal of Modern Trends in Engineering and Research
www.ijmter.com e-ISSN No.:2349-9745, Date: 28-30 April, 2016
@IJMTER-2016, All rights Reserved 971
Autoclaved Aerated Concrete (AAC) Solar Cooker Baviskar Pratiksha1, Desale Rashmi2, Deshmukh Shweta3, Gaikwad Diksha4
Prof.Dr. Sanjeev Suraywanshi5 1-4 Department of Mechanical Engineering S.S.V.P.S’s B.S.D.College of Engineering,DeopurDhule-02,
(BE students) [email protected] 5Department of Mechanical Engineering S.S.V.P.S’s B. S. D. College of Engineering, Deopur Dhule-
Abstract-This paper presents thermal performance of an innovative box type solar cooker constructed by using Autoclaved Aerated Concrete(AAC) blocks.AAC has less thermal conductivity, high strength, low density, long lasting, and good machinability.These promising properties find its application in construction. Also its durability is proven. Review of properties of AAC invites its use in solar cooker manufacturing.AAC solar cooker was tested to cook rice, khichadi and for drying also. The maximum temperature achieved was 970C. Keywords-Box type solar cooker, Low grade material,Autoclaved Aerated Concrete(AAC), Bottom loading, Low cost.
I. INTRODUCTION
The box solar cooker must be of high quality, light weight, affordable, user friendly, stackable. The basic purpose of solar cooker is to heat things up - cook food, purify water, and sterilize instruments. A solar cooker cooks because the interior of the box is heated by the energy of the sun. Sunlight enters the solar cooker through the aperture glass. It turns to heat energy when absorbed by the dark absorber plate and cooking pots. This heat input causes the temperature inside of the solar box cooker to rise until the heat loss of the cooker is equal to the solar heat gain [1] that is thermal equilibrium with surrounding. Autoclaved aerated concrete (AAC) blocks are light weight, environmental friendly. These blocks consist of 80% air by volume. These blocks are made using Portland cement, quartz (silica), water and aeration agent. The mixture of these constituents is poured in mould. These blocks formed as a result of reaction of aluminium on a proportionate blend of lime, cement and fly ash, the hydrogen gas that escapes creates millions of tiny air cells giving it a strong honeycomb like structure. It is further strengthened by high pressure steam curing in autoclaves [2]. The water-cementitious materials ratio is related to the amount of aeration obtained and thus the density. For a given density, water-cement ratio increases with proportion of sand. For AAC with pozzolans, water-solids ratio appears to be more important than the water-cementitious ratio, irrespective of the method of pore-formation. For gas concrete, a lesser water-solids ratio leads to insufficient aeration while a higher one results in rupture of the voids, increase in density being the consequence in both the cases. Thus the water requirement is to be gauged by consistency of the fresh mix rather than by a pre-determined water-cement or water-solids ratio [3]. Thus its density can be varied. Due to high porosity; it has low density and excellent insulation. [2]
International Journal of Modern Trends in Engineering and Research (IJMTER) Volume 3, Issue 4, [April 2016] Special Issue of ICRTET’2016
@IJMTER-2016, All rights Reserved 972
Due to these promising properties (low density, good insulation, light in weight and easy to cut) of AAC blocks, it can be used to construct box type solar cooker. AAC solar cooker is made with low grade material such as AAC blocks and binding material. Glass, aluminium sheet, black paint, angle plates, black painted aluminium utensils. AAC solar cooker has bottom loading and innovative fixation of glass.
II. METHODOLOGY
AAC solar cooker is made up of four AAC blocks having size 625X240X100mm, which are cut in required size as shown in Figure (2) by using cutting, machining and grinding tool.AAC box is formed by binding all the four blocks and then proceed for frame work as shown in Figure (3).Glazing is directly fixed in the slot made and this fixation of glass is innovative as compared to other solar cooker. Mirror of size 450X450 mm is used which is not attached to solar cooker itself. The inside taper surface of box is painted by matte black colour. The aluminium utensils having diameter 160mm and height 57mm are used for cooking.
Figure.1 Design of AAC box type solar cooker (All dimensions are in mm)
Figure.2 Sectional view of block along section AA Figure.3 Cut blocks in assembled position
International Journal of Modern Trends in Engineering and Research (IJMTER) Volume 3, Issue 4, [April 2016] Special Issue of ICRTET’2016
@IJMTER-2016, All rights Reserved 973
Figure.4 Box of AAC blocks with steel Figure.5 Testing of AAC cooker Figure.6 Cooked rice
Frame
III. EXPERIMENTATION
The experimental test on AAC solar cooker was carried out on 10 April 2015(summer) for solar time 11:50 am to2:52 pm in Dhule (74˚45" N 20˚50", 259 m above MSL), India. The AAC solar cooker was placed on blanket (Insulation towards ground) and aluminium absorber on the insulating surface facing solar radiation. But heat lawn can also be used as insulating material to reduce heat loss from bottom. Aluminium cooking pots having cylindrical shape with the thick coating of black paint has been used to cook rice of quantity 250gm with 250ml litre of water. The solar insolation on that day was 7.37229980469kWh/m2/day [4]. The ambient temperature and inner temperature of cooker was recorded by a calibrated digital temperature indicator.
Figure.7 Variation of temperature with time
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International Journal of Modern Trends in Engineering and Research (IJMTER) Volume 3, Issue 4, [April 2016] Special Issue of ICRTET’2016
@IJMTER-2016, All rights Reserved 974
IV. RESULT AND DISCUSSION
Above graph shows increase in temperature with respect to time. Cooking is feasible in AAC Solar cooker. It took two and half hour to cook rice (250gm). Readings were taken after every fifteen minutes. The maximum temperature reached was 970C.AAC solar cooker was also used to cook rice, khichadi and also for drying purpose.
CONCLUSION
From experimentation it is clear that results of AAC solar cooker are as usual as normal solar cooker. Since overall heat loss was more, cooking time was 20 to 30 min more than other solar cookers. There is saving of material due to bottom loading and use of low grade material (such as AAC blocks with its binding material). Cost of AAC solar cooker is 50% of solar cooker available in market. India has good sunshine hours hence AAC solar cooker can be better option. Usage of AAC solar cooker will increase due to low cost and will improve energy conservation in cooking.
REFERENCE
[1] Prof. Viral K Pandya, Prof. Shailesh N Chaudhary, Prof. Bakul T Patel, “Assessment of Thermal Performance of Box Type Solar Cookers under Gujarat Climate Condition in Mid Summer”, International Journal of Engineering Research and Applications (IJERA), Vol.1, Issue 4, pp.1313-1316. [2] Farhana M. Saiyed, Ashish H. Makwana, Jayeshkumar Pitroda, Chetna M. Vyas “Aerated Autoclaved Concrete (AAC) Blocks: Novel Material for Construction Industry”, International Journal of Advanced Research in Engineering, Science and Management, Vol.1, Issue2, pp21-32, 2015. [3] N. Narayanan, K. Ramamurthy “Structure and properties of aerated concrete: a review”, Cement and Concrete Composites 22, pp.321-329,2000. [4] natgrp.org/2012/11/23/nrel-India-solar-resource-maps/ (visited 25/01/2016 at 1.40 pm)
