Download Free PDF View PDF
Download Free PDF View PDF
Download Free PDF View PDF
Download Free PDF View PDF
Design of thermal systems is no longer primarily an art and experience but it has now shifted to a rigorous optimization procedure, the commercial software tools are being routinely used to the best possible design under the conditions at hand. Thermal system design and analysis continues to develop. The number of workers is growing, technical papers appear in greater numbers, and new textbooks are being written. Many concepts like use of information flow diagrams to simplify the simulation procedure, novel optimization methods suitable for thermal system simulation, etc. have been developed. Researchers have developed detailed simulation procedures for equipment used in refrigeration systems. Also thermal power plants and novel desiccant-based cooling systems have been developed over the years. This paper discusses briefly the procedures for thermal systems design, simulation and optimization developed over the decades.
Download Free PDF View PDF
Download Free PDF View PDF
The aim of this paper is to demonstrate by means of relevant examples the usefulness of Excel as a tool for introducing computer-aided design optimisation to engineering students.The performance of thermal systems is strongly influenced by the cost of energy which constitutes a major part of their running cost.Thermal design, which must take into consideration operating costs as well as initial costs, offers good examples of design optimisation. Moreover, design optimisation of thermal systems can easilybe performed by using Excel. The examples considered in the paper deal with insulated conduits carrying hot or cold air with respect to initial and energy costs. Unlike analytical optimisation that can only be used for simple situations with a single design parameter, Excel can deal with thermal designs that involve multiple design factors and elaborate analytical models. I. INTRODUCTION Thermal-fluid systems,or simply thermal systems,are mechanical-engineering systems that are used for the transfer and utilisation of thermal energy in industrial, residential, and many other applications. Thermal design refers to the design of these systems that is based on the principles of thermal sciences (thermodynamics, fluid mechanics, and heat transfer). The design of thermal system is strongly influenced by the cost of energy as well as environmental regulations that vary with location and time. Therefore, the acceptability of a thermal system does not depend only on its initial cost, but also on its running cost. Thermal design can be used to illustrate the concept of design optimisation more effectively than conventional types of mechanical-engineering design [1]. Like conventional design, thermal design is an iterative process that requires the use of computers and computer software. In order to deal with design assignments, standard textbooks in the field of thermal engineering now use relevant computer software[2,3]. By eliminating the tedium of property tables and charts, computer software helps the students to improve their designs by performing sensitivity and optimisation analyses that lead to more efficient systems with less energy consumption and lower impact on the environment. Unfortunately, such applications are usually protected by proprietary rights and, therefore, they are inaccessible for many engineering students particularly in developing countries. Microsoft Excel,which comes as part of the widely-distrbuted Microsoft Office software, is is a general-purpose spreadsheet application that is usually taught to junior engineering students within an introductory course in computer application. Although Excel is an extremely versatile application,itismostly used only for data analysis and presentation. However, Excelis equipped it with the necessary tools that allow students to perform design optimisation analyses. Moreover, the computational capabilities of Excel as a modelling platform for engineering analyses can be extended significantly by taking advantage of Visual Basic for Applications (VBA), which is a well-equipped programming language that also comes as part of Microsoft Office. VBA can be used for developing additional user-defined functions as required by thermal analyses [4]. With the wide availability of personal computers nowadays, Excel can be a useful modelling platform for mechanical engineering students and practicing engineers alike. Ithas already been used as an effective educational tool for introducing the basic concepts of thermal sciences[5-8]. The present paper focuses on using Excel for design optimisation of thermal systems. By means of relevant examples, the paper demonstrates the adequacy of Excel, together with its Solver add-in,as a modelling platform for thermal design optimisation. The paper also highlights the advantages of computer-aided optimisation compared to analytical optimisation of thermal systems design.
Download Free PDF View PDF
TECNICA ITALIANA-Italian Journal of Engineering Science
