Applied Mechanics and Materials Vols. 110-116

Abstract: We are aware of the present scientific concerns regarding greenhouse gas emissions and the role of fossil fuel use for power generation. Although the scientific and policy dialogue on global climate change is far from conclusive, we want to design high efficiency power generation equipment with the most modern technologies to utilize fossil fuels with the lowest possible emissions and technologies to remove and sequester carbon dioxide created in power plants in an environmentally and economically favorable manner. This paper is an overview of activities to study and develop controls for carbon dioxide (CO₂) emissions from power generation. First, energy efficiency improvements for both new and Existing fossil fuel power plants are briefly reviewed for both coal and natural gas fuels. Greater depth is then given to options for CO₂ capture and sequestration. These studies are looking at current and novel power generation technologies.

Abstract: One of the biggest challenges that the world faces is definitely the need for more energy. As the world’s fossil fuel supplies dwindle down, it becomes more and more important to find clean sources of energy that can also fulfill the global demand for more energy. Fortunately, aerospace technology can be of use, as the moon can be used to harvest ³He, which can be a clean source of nuclear fuel for fusion reaction on Earth, as well as on the moon. This paper will demonstrate that the concept of moon mining needs to be explored further as ³He can be of great use for solving the world’s energy needs.

Abstract: Lean manufacturing has been proved to be an effective management philosophy for improving businesses in a competitive market by eliminating non-value added waste and improving in process operations. Value stream mapping is an important tool used to identify the opportunities for various lean techniques. The present research mainly focuses on the description of a model that is developed to contrast the “before” and “after” scenarios in detail in order to obtain the various benefits such as reduced production lead time, lower work in process inventory [1] and proper utilisation of the workforce. The current manufacturing system has been compared with the proposed pull (Kanban) system which shows the benefits of the proposed lean manufacturing system over the existing traditional manufacturing system. The present research work has been carried out at typical tractor industry which shows 50.5% reduction in total lead time in the future state value mapping of the crank case and the number of operators involved in processing of crank case has also been reduced from 22 to 18.

Abstract: The air-cooled condenser system is impacted greatly by many factors such as the wind speed, the direction of wind and arrangement of site equipments. This paper concentrates on the hot air recirculation phenomenon and its dependence on ambient winds are numerically simulated by using the computational fluid dynamics code, FLUENT. In this paper, two different wind directions (case A and case B) and wind speeds are considered: Results show that the hot air recirculation increases with the increment of velocity speed. Case A has a critical wind direction angle. Wind causes an air temperature increase at the fan inlet due to hot air recirculation, resulting in the deterioration of the heat transfer performance. The hot air recirculation is the main factor responsible for the reduction of heat rejection rate. In case A, fan inlet temperature is higher than case B. The peak value of the HAR occurs at 9 m/s in case A.

Abstract: Now a day’s consequences such as increasing air pollution and environmental contamination, reduction in natural resources and energy crisis which are due to the present industrial life, has made the human being to regard conservation of natural resources as the most important issue at the present time. Green architecture plays an important role in this regard by improvement in building efficiency, saving the energy, putting steps toward using new types of energy and all in all being in the same direction with the nature. Considering that 50% of energy consumption is done in buildings the idea of the Zero energy buildings is created to provide the energy needs in the 21st century. In the ZEB using the highest renewable technologies the balance between the amount of the produced energy and consumed energy is achieved. In this paper we tend to study the basics of construction of such buildings.

Abstract: Population growth, finishing and wasting the energy sources, the contamination from the fossil fuels and finally the corruption in the environment are the factors which are alarming the limits the future of the human beings and also the underlying dangers. Considering the existing limits the only correct way is the right use of energy, optimization in the energy consuming appliances and using new returnable sources of energy in order to control the energy crisis. So using the new sources of energy instead of fossil fuels is obligatory. So the new sources of energy should rely on structural and fundamental changes in which the solar energy is used in them and using this source of energy is a based in this type of construction and sustainable architecture which can solve many of present problems of society in optimizing energy consumption. In this article we have worked on solar energy as a returnable source of energy in buildings and the relevant effects on energy consumption reduction and the effects on architecture stability.

Abstract: The purpose of this paper is to provide a greater understanding of the implementation process of lean production in China. In particular, it will investigate the main barriers when implementing lean production in China. The aim is to evaluate if implementation barriers can be explained by Chinese national context factors. Case studies of two auto-parts production plants of a German multinational company in China were used to evaluate lean barriers within China. During a two month research trip to China, sixty interviews with Chinese and Western employees were conducted to evaluate barriers when implementing Lean in China. Strong evidence is found that Chinese context factors do significantly influence the implementation process of lean in China. The paper proposes the necessity for organizations to consider cultural, socio-political and economic context factors of China when applying lean principles. The fieldwork leads the author to develop a model of barriers which restrain the successful implementation of lean production systems in China. Beside a comprehensive compilation of barriers, the model indicates Chinese cultural, socio-and economic national context factors which may influence the implementation barriers.

Abstract: In the villages of developing countries, use of electricity or petroleum fuel is expensive for drying the agricultural products. In the current scenario, drying through “natural convection grain dryer” is an important alternative. This paper proposes the development and evaluation of the natural convection grain dryer in drying performance of paddy. The proposed system is capable of generating an adequate and continuous flow of hot air with range of 60-70 degree centigrade. Paddy was successfully dried from 33% moisture content to 14% (w.b). Woodchips (biomass) were burnt to heat the incoming air in the dryer. Experiments were conducted with fixed amount of sensible heat storage material with varying the amount of latent heat storage material. Increase in the latent heat of storage material indicates the improvement in standard drying temperature, time and enhancement in amount of paddy dried. Re-firing further enhances the duration of optimum temperature range for quality drying.

Abstract: The objective of this work is to review state of art practices and potential in diesel engines using greener fuels. Biogas with jatropha bio-diesel as ignition source was tested in a compression ignition diesel engine at six different loads under dual fuel mode. With a simple modification, the base engine was qualified to a dual fuel operation. For all the loads evaluated, dual fuel mode achieved a possible bio-diesel substitution of about 65%. In addition, it consumed lesser friction power as compared to the diesel mode during the operation. There were reductions in thermal efficiency, cylinder peak pressure and combustion noise under the dual fuel operation than the diesel mode due to lower burning velocity of biogas together with a longer pilot delay. However, this operation registered extremely lower NO_x levels at all loads along-with reduced CO emissions at medium and higher loads. While significant increases in hydrocarbon emissions were observed.

Abstract: The water and steam injection gas-turbine systems are comparatively investigated. Thermodynamic performances of the regenerative after-fogging gas-turbine (RAF) system, steam-injection gas-turbine (STIG) system, and the regenerative steam-injection gas-turbine (RSTIG) system are analyzed parametrically. Using the analytic model, the important system variables such as thermal efficiency, fuel consumption, specific power, and specific emission of CO2 gas are evaluated in terms of pressure ratio and water or steam injection ratio. The numerical results show that water or steam injection results in a notable enhancement of thermal efficiency and specific power.