How to Produce Energy-efficient Machines - Former DVC

The immediate past Deputy Vice-Chancellor (Academic) of FUNAAB, Professor Adekojo Waheed, of the Department of Mechanical Engineering, College of Engineering (COLENG) of the University, has identified the research benefits that could come the way of industries, petrochemical companies and the nation at large in the area of exergetic utilisation in producing energy-efficient machines.

The University Don, who disclosed that his research interest was in the area of “Fluid Mechanics, Heat and Mass Transfer”, said that he uses his knowledge in energy studies implementation to know the impact on plants and the environment, in order to minimise energy consumption on a large scale, find out from the existing plants the problems they were facing and how such could be solved. Professor Waheed disclosed further that he had worked on cooling devices such as air-conditioners and refrigerators, saying that he had also tried to find out how cooling could be achieved without the use of electricity, as cooling could also be achieved using solar energy by evaporation process.

According to Professor Waheed, what spurred him into this research was his interest in solving problems that would make life easier for the people, adding that nothing could be done without fluid, while his work tried to find out how to reduce energy consumption for the benefit of humans and what could be done with all the fluids available for increase in profit. The Professor of Thermofluids opined that his research would help companies reduce their energy utilisation, in order to increase their profits, noting that it would make the country depend less on packaged technology, reduce emission to the atmosphere that would assist in producing sustainable environment and ensure sufficient energy.

Speaking on his contributions to research, the former Deputy Vice-Chancellor (Academic), pointed out that as a Professor of Thermofluids, a discipline in Mechanical Engineering, his researches focused on Computational Fluid Dynamics, Heat and Mass Transfer, and Energy Techniques. According to him, “basically, the primary duty of an engineer is to design/develop machines for man and industry. So, I am actively engaged in the design of energy-efficient fluidic equipment for industrial use. Flow processes occur in technical devices such as aggregates, instruments, machines and plants, in order to transfer energy, generate lift forces, run combustion processes or take on control functions. The power that is used in cars, trucks, ships and aeroplanes is generated through fluid-flows, coupled with chemical reactions that enable the combustion in piston engines. The basic understanding of the behaviour of flowing fluid is essential for the design of such industrial processes in which fluid flow and associated phenomena play predominant roles”.

Professor Waheed, who disclosed that the traditional ways of carrying out research in fluid mechanics was to engage theoretical/analytical (analytical fluid mechanics) and experimental solution (experimental fluid mechanics) approaches, however, noted  that due to the limitations of the traditional approaches and very high cost of experimentation in fluid mechanics, the third approach, which was based on the numerical solution methods (numerical fluid mechanics), called Computational Fluid Dynamics (CFD), was introduced. “CFD is the science of predicting fluid flow, heat and mass transfer, chemical reactions, and related phenomena by solving numerically the set of governing mathematical equations of conservation of mass, momentum, energy and species mass, among others. It is a very robust and rigorous approach that has been successfully used in the design of very complex machines, industrial unit operations and processes”, he added.

“One of the areas of my contributions to the fascinating world of engineering was in the improved design and dimensionalisation of the liquid-liquid extraction and distillation columns. Liquid-liquid extraction and distillation processes are useful method to separate components of a mixture. They are used in wide variety of industries including chemical, pharmaceutical, effluent treatment, polymer processing, petroleum, petrochemicals and food industry, among others. The process of separation of one component from the others, through liquid-liquid extraction, is normally done by bringing into contact two immiscible phases and by transferring a mutually-soluble component from one phase to the other. In practice, one phase is usually dispersed in the form of swarm of liquid droplets either from below or above the column droplets into the second continuous flow phase with the aim of providing large inter-facial contact area, per unit volume, between the two phases by enhancing the rate of mass transfer.

In the case of distillation, a phase is dispersed in the form of bubbles into the continuously flowing phase. The diameter of droplets and bubbles are usually in the range 0.5 to 1 mm, making it very difficult to analyse the internal and external flows in them. However, the knowledge of the relevant fluid dynamics of a single droplet or bubble in a second flowing liquid phase, is essential to determine the effect of various forces, including drag and lift acting on them and for the solution of convective mass-transfer problem of the droplet/bubble. In addition, the mass transfer in a single drop is the basis for the estimation of the mass transfer in a polydispersed system and, hence, for the design of an extraction/distillation column”.

Professor Waheed revealed that the conventional distillation system was widely used in the petroleum and chemical industries for the separation of fluid mixtures, but was highly energy intensive, adding that the Nigerian refinery was making use of the crude distillation unit, comprising various individual distillation units, which are also energy intensive.  

Shedding more light, he said the refining industries in Nigeria are confronted by many circumstantial problems including rising energy utilisation, problem of emission control and under-production, stressing that that was what gave him  the insight to carry out an exergetic study of the plant to proffer solution, and “our findings showed components that are both energetic and exergetic-highly inefficient. Our contribution was in the redesign of such components including heat exchanger network, preflash unit and atmospheric distillation unit. We came up with five different developed models of the modified vapour recompression heat pump modified which are of improved exergy; efficiency and lower emission”.  The Don said he had also worked on the development of basic and essential laboratory equipment. One of such being a steam generator or steam boiler, which is a closed vessel, usually used to produce steam from water by combustion of fuel for use in industries for the production of goods, food, heating and cooling of large buildings, running of equipment and production of electricity.

“Steam boilers may be of different shapes and sizes, depending on their applications. Boilers have been in use for a very long time and over the course of time; various inventors and engineers have developed and modified them for the purposes of academic study, as well as to suit the needs of the modern man. In science and engineering laboratories, there is sometimes, the need to utilise steam or hot water to generate power,  carry out tests or used for other heating applications. Many higher educational institutions in Nigeria do not have this very useful device because of its high cost, since it is not being produced locally. We designed a fire-tube steam boiler suitable for use in laboratories as a research rig for power generator among others. The designed boiler can be manufactured locally at highly competitive cost with the materials of all components sourced from within”.

According to him, another device developed was a solar thermal-driven adsorption refrigeration system that works on the principle of cooling, by evaporation. The system neither has any moving part nor uses any energy other than the thermal solar energy, unlike the convectional vapour compression or absorption refrigeration system, which uses electricity. The developed system does not make use nor emit global warming and ozone-depletion substances, making it environmentally-friendly and the system running at minimal cost after the initial cost of investment.

Professor Waheed, however, noted that his research work was facing a lot of challenges, adding that the needed facilities for research were not there. He named such constraints to include lack of facilities for simulation in the laboratories, irregular power supply, poor attitude of industries to research and inadequate drive by students to work with researchers. The Professor further disclosed that engineers were facing more challenges than other researchers because most developed countries, assisting local researchers, were not always ready to support developmental/technological research.

He added that Nigerian researchers possess the potentials to achieve anything they wanted to achieve, noting that despite the challenges, the researchers would rather not give up; instead, they would prefer to focus more on light technology that would be of great benefits to our people. He added that most Nigerian researchers were involved in research merely because of getting promoted on the job; a practice he said, should not be. For him, research should be done painstakingly, adding that it may take several years, but at the end, the result would be a great breakthrough that would bring joy and fame to the researcher as well as the country.

Professor Waheed, who is also a former Director, Academic Planning of the University, advised the government to have a way of generating funds that would be set aside for research and make it mandatory for industry to collobarate with higher education institutions in the country. He added that there should be a programme that would also enlighten researchers, in order to change their attitude, such that they would carry out more researches that could touch the lives of the people, positively.