Abhishek Saxena

Solar Air Heaters with Thermal Heat Storages

Solar energy can be converted into different forms of energy, either to thermal energy or to electrical energy. Solar energy is converted directly into electrical power by photovoltaic modules, while solar collector converts solar energy into thermal energy. Solar collector works by absorbing the direct solar radiation and converting it into thermal energy, which can be stored in the form of sensible heat or latent heat or a combination of sensible and latent heats. A theoretical study has been carried out to rate the various thermal energy storage commonly used in solar air heaters. During the investigations rock bed storages have been found to be low type thermal heat storage, while phase change materials have been found to be high heat thermal storages. Besides this, a few other heat storing materials have been studied and discussed for lower to higher ratings in terms of thermal performance purposely for solar heaters.

A Technical Note on Fabrication and Thermal Performance Studies of a Solar Pond Model

A solar pond has been fabricated to analyze the thermal behavior of it, in the climatic conditions of Moradabad, Uttar Pradesh. Sodium chloride (NaCl) has been used to form a salt gradient for better performance, and a dark-colored (blackened) rigid surface bottom with 1 mm irregularities has been considered for trapping the heat in a good amount. A solar pond with a surface area of 2.56 m2 and a depth of 1 m has been filled with salty water of various densities to form three salty water zones (upper convective, nonconvective, and heat storage). A few investigations have been carried out to evaluate the thermal efficiencies of three different zones of the solar pond. An attempt is also made to improve the thermal performance of the salt gradient solar pond.

A technical note on performance testing of a solar box cooker provided with sensible storage material on the surface of absorbing plate

A box type solar cooker having a double glass cover and a plane mirror reflector has been tested for its thermal performance. In the present study, performance of solar box cooker has been compared by using two different sensible heat storage materials (sand and granular carbon). By using these materials as a mixture and spread it over absorber tray in the form of thin layer and fully packed with a float glass shows the significant improvement in the performance of box type solar cooker.

Design and Performance Analysis of a Solar Air Heater With High Heat Storage

ABSTRACTThe aims of this work is to enhance the efficiency of a simple designed solar air heater for crop drying and space heating. ‘Desert sand’, has been introduced as a heat absorbing media inside the solar heater. The experimental testing has been carried out on four different configurations by operating it on natural and forced convection in the climatic conditions of Moradabad, India. The thermal behavior of the system is evaluated by operating it on auxiliary power by placing a halogen lamp tube (300W) inside the inlet and outlet ducts. Because of using halogen lights the system is feasible to perform in poor ambient conditions. The thermal performance of all new configurations of the modified system was found better over a similarly designed conventional solar air heater.

Solar Food Processing and Cooking Methodologies

In this study, a theoretical analysis of food processing (e.g., solar drying), worldwide cooking pattern, and cooking methods by using the solar energy has been reviewed. Solar food processing method is applied as direct absorption, air heater, and a combination of direct and indirect drying by solar radiation. Therefore, this process is one of the most accessible and hence the most widespread processing technologies. Traditional solar drying involves keeping products in the direct sunlight. Solar drying and cooking processes take place at different temperatures and timescales, and it depends on the nature of the food or substance. The amount of solar energy that reaches to the system and design parameters determines the performance of food processing and cooking systems. The time duration of drying and cooking depends on the temperature of heated air and environment. The temperature distributions, mass, and ingredient of food have an important role in the performance of dryers and cooker boxes. For a better understanding of the system parameters, the concept of solar food processing has been discussed thermodynamically. Energy saving by using solar systems has also been discussed.

Steven G. Penoncello: Thermal energy systems: Design and analysis

Thermal fluid energy system design has a major role in the field of engineering science and technology from an undergraduate level course up to various research level programmes. This book offers a fundamental employed knowledge of ‘design and analysis of thermal fluid energy systems,’ ‘permitting users to effectively formulate’ and ‘optimize and examine’ their own design projects. This book provides a merit in the pool of knowledge and intelligence for undergraduate, postgraduate, research level courses (higher education) and professionals from industries. This book is well written and organized in a presentable form to provide an excellence in the design of thermo-fluid systems with the basic concepts, laws, tools and practical examples. The selection of topics is good and provides an attentive review of basic thermal fluid engineering fundamentals. It presents the engineering design process in a practical way with especially highlighted engineering economy concepts with optimization. It also covers numerical and computational methodologies with an introduction of EES software. The material inside the book fits attractively with the kind of industrial practice for the students after graduation. Overall, it can be said the present book is well organized and useful for the persons from academia and industry (i.e., for designers and researchers). This book also offers the elementary concepts of simulation and optimization with some good approachable techniques that can be applied to a system model. It addresses: hydraulic systems, energy systems, thermal engineering concepts, principles of engineering economics, application of conservation and balance laws, fluid flow fundamentals, series and parallel pipe networks and pump systems, pump performance and selection, cavitation, the affinity laws for pumps, heat exchangers and their types, LMTD, and e-NTU methods, regenerative HX, condensers, evaporators, and boilers, thermal energy system simulation, fitting component performance data, optimization using Lagrange multipliers, optimization using software and use of EES. In addition, it incorporates both the SI and English units and develops state-of-the-art computer simulation. About the book, it has total six chapters with 172 black and white illustrations (subdivided into 229 figures), 59 tables (subdivided into 81 tables), 55 solved examples and 143 unsolved problems including 07 appendixes. & Abhishek Saxena culturebeat94@yahoo.com

A Review of Recent Patents on Solar Air Heaters

This paper focuses on a review of the recent patents of the solar air heaters which are used for drying, space heating and timber seasoning, etc. A solar air heater deals with a simple blackened absorber tray, an insulation material to prevent heat losses, one or more transparent glass covers for thermal trap, two individual ducts for air inlet and exhaust and an electric blower (for forced convection). Some novel designs of the solar air heaters from 1952 up to now have been discussed (depending on the fundamental design principles) and categorized by using a classification system. After reviewing some good patents, it has been originated that there are many comprehensive patents covering the detail design, importance of part elements functioning and performance of the air heaters. Conversely, there are a limited data available, research articles, and viable products to compare the advantages over each other. Therefore, the modification or the improvement must be focused on the design and configuration of the elements of the system. It will direct to understand the performance limitations, tradeoffs, and advantages of typical designs and components in comparison against each other. This study will improve the understanding of students, scholars, researchers and developers as well as strengthen the overall logical asset archive and the knowledge pool for the solar air heating systems.

Andre G. McDonald and Hugh L. Magande: Introduction to thermo-fluids systems design

This book provides an excellence in the pool of knowledge and intellect for undergraduate, post graduate and research level courses as well as the professionals from the industries to supply information on the design of thermo-fluid systems with the basic principles, fundamentals, tools and practical examples in the field of engineering and technology. The selection of topics is designed to provide the reader with an introduction to the language, concepts and techniques used in the design of all the major thermo-fluids systems. This book can serve as a useful reference because it collects equations and other information from mechanical, industrial and chemical branch of engineering and science in one book. Many practical examples (27), illustrations (90), tables (48), appendices (07), practical notes (35), list of conversion factors and an index is provided to help the reader in the given six chapters. Problems for almost all the chapters are designed to help the reader to understand the concepts and apply the material to real situations with related references. Themes in the book include thermal systems design covering fluid dynamics, thermodynamics, heat transfer, the fundamental concepts of fluid mechanics and thermodynamic power cycles. This textbook focuses on the design of internal fluid flow systems, coiled heat exchangers and performance analysis of power plant systems. The topics are in order so that each builds upon the prior chapter to express to the reader that topics are not impartial items during the design process, and that they all must come mutually to produce a flourishing design. It is notable that charts, figures and other data tables cited from the referred manufacturer’s catalogue by the authors are excluded in the review while the tables and figures are provided in appendices are included. Authors have been introduced the basic fundamentals of design in thermo-fluid science in a very pleasant and understanding manner. Chapter 1 deals with types of design in thermo-fluid science (process, system, subsystem and component design), classification of design, the general steps and abridged steps in the design process with the help of a figure (01). Chapter 2 presents the theory and analysis of air distribution systems in detail. The term ‘internal flow’ with criteria for flow characterization, major and minor head losses in ducts and pipes, procedure for using the Moody chart, and several correlation equations are presented to find the friction factor in fully developed turbulent flow in pipes/ducts as;

Sanford Klein and Gregory Nellis: Thermodynamics

This book provides a real excellence in a pool of knowledge and intelligence for graduate; post graduated and doctorate level courses in thermodynamics with the basic principles, concepts/fundamentals, tools, and practical examples in the field of engineering and technology. The selection of all the 16 chapters is structured to provide a good introduction to the subject and its importance to its reader. The concepts and techniques used in all major concerns of thermodynamics such as; entropy, enthalpy, power cycles, refrigeration cycles, heat pumps, combustion process, psychometric, and fluid flows are explained well and in an understandable manner. A total of total 82 examples, 415 colored figures, and 54 tables are given in the book (including the figures, and tables of solved examples and appendixes). Figures with their subsections say ‘‘a’’, ‘‘b’’, ‘‘c’’, are counted as one figure. Apart this, a computer programme ‘‘Engineering Equation Solver— (EES)’’, is introduced as a platform for numerical solution of the problems in an approachable manner (as well as eliminating the mathematical complexity involved to solve thermodynamics problems). Besides this, EES has been featured to check the dimensional and unit consistency of the equations. All the illustrations, tables, appendixes, as well as references are provided for better understanding the terms, their meanings, and source of referred literature to its reader. Chapters 1 and 2 deal with fundamentals of ‘‘Thermodynamics,’’ such as: laws of thermodynamics, thermodynamic states, and properties of various fluids used for heat transfer (heating and cooling). Fluid property data of the type, represented by smart figures, and based on the available data (mainly for liquid water and for steam) or sets of data (provided in the Appendix). A basic introduction of EES is given by solving the different problems of heat transfer and energy balances for thermal systems. Operations such as; vacuum by condensation, superheated vapor, thermostatic expansion valve, thermal driven compressor, and fire extinguishing system are explained well in details. Chapter 3 serves a practical theory and relative information on heat transfer and thermal behavior of the open and closed systems under various loads or ideal conditions. The energy balance equations are discussed to determine the thermal behavior of the systems in this section. It has also been stated and discussed that energy is a conserved quantity (in the terms of function of various works) in this chapter. Chapters 4 and 5 have been designed purposely to make comprehensible the concepts of first and second law of thermodynamics and their applications. A general methodology for solving thermodynamics problems that can be summarized as;