International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 04 | Apr -2017
p-ISSN: 2395-0072
www.irjet.net
Analysis of “Solar Radiant Heat Flux” Through Concrete Slab Pradnyesh J. Thakur1, Sandeep D. Khilari1, Akshay A. Kadam1, Aditya Y. Yadav1 Guide Prof. Vasant G. Gughe2 1Students, department of mechanical engineering, DILKAP Research Institute of Engineering and Management Studies, Neral, Tal-Karjat, Dist- Raigad, Maharashtra, India. 2Professor, department of mechanical engineering, DILKAP Research Institute of Engineering and Management Studies, Neral, Tal-Karjat, Dist- Raigad, Maharashtra, India ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - The project work has been undertaken during
the day the earth’s atmosphere is warmed by solar radiation from the sun, providing the energy that we need to sustain life. But this solar energy flow needs to be kept in balance, and in simplistic terms, the earth does this by re-radiating part of the energy received from the sun back to the sky at night. In this way a balance can be achieved between the solar warming from the sun and solar cooling from the night sky. By utilizing the advantages of night sky radiation the temperature of human residential place is to be control by following method. When in the day the roof of the house will be cover by combined tarpaulin and aluminium insulation sheet from 6am to 6pm every day from sunup to sundown this flexible cover, with a very shiny bottom is drawn over the slab. It shades the slab of house while its low emissivity (0.01) due to the shiny surface prevent any radiant heating of the slab so the slab gains some heat from the ambient air, and its bottom still remains human comfort at least five degrees below the body so it feels cool in a day. During the night, the slab remains open to the sky. This allows radiant heat transfer from the slab to surface that is 30 Degree Celsius to the sky. The rate depends on the difference in the fourth powers and the emissivity of the slab (0.85). So the slab bottom cools down to human comfort in the night. To analyze one dimensional heat conduction through slab. To obtain maximum heat transfer at night time from concrete slab to atmosphere. To obtain maximum temperature drop during day of the concrete slab compared to ambient.
These problem is overcomes by experiment on an extremely simple roof cooling system which involves to cover the roof during the day by a low emissivity cover and withdrawing it at night, exposing the roof for cooling by radiation to the sky.
1.2 General Introduction During day we are using radiant barrier. Radiant barrier is a shiny panel or flexible membrane used in construction. They can be used as part of assembly for example, an assembly made up of a radiant barrier to slow heat transfer. By definition, a radiant barrier has a low emissivity (0.1 or less). Radiant barriers reduce radiant heat transfer across the space which they face. The lower a material’s emissivity, the more effective it is at reducing radiant heat transfer. During nights with a clear sky a strong surface cooling of objects oriented towards the sky is observed. The large radiation heat flux of about 40 – 75 W/m2 (watt per meter square) in clear-sky nights can be much larger than the convective heat flux, leading to measurable consequences in the thermal signature of buildings. The surface temperature of objects directed to the sky with a large angle of view is often decreased below the temperature of the surrounding air. This radiant cooling can cause a significant change of the thermal signature of object surfaces depending on the effective background temperature of the night sky, the radiation distribution within the field of view (influencing the net radiation flux) and the tilt angle of the object.
Key Words: Heat transfer; Aluminimum film; Human comfort; concrete cealing; Low emissivity; Radiant barrier.
2. CONSTRUCTION
1.INTRODUCTION
2.1 Design of frame:
1.1 Problem Statement:
Frame is an important property of every project. Roof frame is designed in Creo 2.0 Refer the Figure No.1
For every person using air conditioner or air cooling, there are many more who can’t afford either and have to suffer extreme discomfort when their house turns into virtual oven in the summer, resulting in sickness and even death.
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