Conference Papers

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Author: search.filters.author.Mahapatra, D.

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    Variation of Time Lag, Decrement Factor and Inside Surface Temperature with Solar Optical Properties of Building Envelope in Different Climatic Zones of India
    (Springer, 2020) Mahapatra, D.; Ashok Babu, T.P.
    Maintenance of thermal comfort inside buildings requires a significant amount of energy. According to the Centre for Science and Environment, the energy spent on achieving thermal comfort in commercial buildings and in residential buildings are 31% and 7%, respectively. Considering the energy crisis that world has been suffering; every individual should try to save energy by some means. The increase in urbanization over the last few years gave rise to boom in constructions. Choosing the materials used for the construction of buildings wisely can contribute towards energy saving. The solar optical properties of building envelope affect the surface temperature up to a great extent which in turn affects the energy used for thermal comfort. In this paper, the effect of solar optical properties on time lag decrement factor and inside surface temperature is studied in different Indian climatic zones. © 2020, Springer Nature Singapore Pte Ltd.
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    Analytical computation of thermodynamic performance of various new eco-friendly alternative refrigerants applicable for air conditioners
    (Springer Science and Business Media Deutschland GmbH info@springer-sbm.com, 2021) Vali, S.V.; Ashok Babu, T.P.; Mahapatra, D.; Saboor, S.; Gorantla, K.K.; Sai Siva Subramanyam, V.
    The objective of the present investigation is to do the theoretical thermodynamic analysis of various new eco-friendly R22 substitutes used in vapour compression refrigeration (VCR) cycle. In this work, nine mixture refrigerants were considered at different compositions. Thermodynamic properties of all the considered refrigerants were developed and the same properties were used in the performance analysis of alternative refrigerants. Standard VCR cycle was considered for the thermodynamic assessment of alternative refrigerants. The working conditions considered are expressed as Te = 7.2 °C, Tk = 54.4 °C, ΔTsup = 11.1 °C and ΔTsub = 8.3 °C, respectively. Results revealed that the COP of mixture refrigerant MR20 (R600a/R134a/R1270 5/47.5/47.5 in mass%) was 2.02% higher than the COP of R22 and other nine investigated refrigerants. Discharge temperature of compressor obtained for MR20 was 11.79 °C lower compared to that of R22. Compressor power obtained for MR20 was 1.96% lower than that of R22. Volumetric refrigeration capacity obtained for MR20 was relatively closer to that of R22. GWP100 of MR20 (619) was lower compared to the GWP100 of R22 (1760). Overall, the performance of mixture refrigerant MR20 was better compared to all the considered R22 alternatives, and therefore it might be an appropriate candidate to replace R22 used in air conditioners. © Springer Nature Singapore Pte Ltd 2021.