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

ABSTRACT

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.

GRAPHICAL ABSTRACT

KEYWORDS:

• Thermosyphon heat transport device
• natural circulation
• Fresnel lens
• indoor solar cooker
• solar chulha
• cooktop module

Highlights

• The hypothesis of an emerging passive indoor solar cooker has been tested

• CFD model is validated against a preliminary experimental investigation

• A practical indoor solar cooking system is tested numerically

• The study proved the technological efficacy of the proposed indoor solar cooker

Acronyms

CNCS	=	Coupled natural circulation system
FPC	=	Flat plate collector
HSF	=	Heat source fluid
HTF	=	Heat transfer fluid
NC	=	Natural circulation
PDR	=	Parabolic dish reflector
THTD	=	Thermosyphon heat transport device

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Ethical Approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Consent to participate

All the authors give their consent to having participated in the current work

Consent to publish

All the authors give their consent for publication of this work.

Additional information

Funding

The authors gratefully acknowledge the financial support from Manipal Academy of Higher Education under Intramural funding (MAHE/CDS/PHD/IMF/2019).

Notes on contributors

K. Varun

Mr. K. Varun is a PhD Research Scholar in the Department of Mechanical and Industrial Engineering at Manipal Institute of Technology, Manipal, India. He is currently working on developing an indoor solar cooking system using thermosyphon heat transport devices. His research interests are heat transfer augmentation techniques, thermal management of photovoltaic modules, solar thermal systems, natural circulation loops, and thermosyphon heat transport systems.

U. C. Arunachala

Dr. Arunachala U Chandavar is a Professor in the Department of Mechanical and Industrial Engineering at Manipal Institute of Technology, Manipal, India. He has more than 20 years of research and teaching experience. His research interests include analysis of solar thermal systems, thermal management of photovoltaic modules, stability analysis of natural circulation loops, thermosyphon heat transport systems, heat transfer augmentation of thermal systems and heat exchanger analysis.

P. K. Vijayan

Dr. Pallippattu Krishnan Vijayan is the Dean-Academics and honorary Professor in the Department of Chemical Engineering at Indian Institute of Technology Jammu, India. He had previously worked at Baba Atomic Research Centre, India. He worked in various positions, such as Head - Thermal Hydraulics Section, Head - Reactor Engineering Division and Director - Reactor Design & Development Group. He has worked in the field of thermal hydraulics of nuclear reactors and has more than four decades of experience in this field. His contributions to the field of natural circulation systems are well known.