Sustainable mechanism to popularise round the clock indoor solar cooking–Part II: workable solution

Solar cooking is one of the significant applications of solar thermal conversion systems. In some of the developing countries of Asia and Africa, firewood was the only cooking option. Hence, outdoor solar cookers have gained popularity in such places due to household air pollution caused by the former. With the onset of urbanization, few developing countries have adopted kerosene, coal, and liquified petroleum gas in place of firewood, which in turn leads to the emission of harmful gases in the kitchen. On the other side, solar cooking has poor social acceptance in developed countries as it is an outdoor activity i.e. under the sun. Hence, a detailed review concerning the outdoor (in general) and indoor (in specific) solar cookers have been presented in part I of this paper: “Sustainable mechanism to popularize round-the-clock indoor solar cooking–Part I: Global status.” It reveals the importance of indoor solar cooking and the dearth of relevant experimental and numerical studies. Such a system is also essential to popularize solar cooking in developed countries (wherein electric cookers have already gained momentum). Hence, the present study proposes a passive indoor solar cooking system that can perform round-the-clock indoor cooking. The hypothesis of the proposed passive indoor solar cooking system, which is based on a coupled natural circulation system, is experimentally investigated with relevant assumptions. It yields the desired output and can perform efficiently without heat input, replicating off-sunshine hour cooking. Later, the experimental results are used to validate a numerical model (Ansys Fluent), which is further extended to replicate a practical system. Upon defining the appropriate boundary conditions, the numerical results depicted repetitive boiling (1 l of water for nine times) in the time range of 680–1500 s with heat load (daytime operation) and 700–1000 s without heat load (replicates off-sunshine hour cooking). Thus, the focused design is quite feasible, and with further recommendations being invoked, the evolution of a sustainable mechanism for round-the-clock indoor solar cooking is apparent.