Invertis Journals of Science & Technology

Arun Kumar ¹, B. N. Agrawal ², Nitin Kumar ¹

Affiliations
1 NGF College of Engineering and Technology, Palwal, Haryana, IN
2 Delhi College of Technology and Management, Palwal, Haryana, IN

Abstract

Zinc oxide and many other materials have long been used in thermoelectric devices for Waste heat recovery to convert heat into electricity. The performance of these materials depends on the figure-of-merit ZT (=S2σ T/κ), where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the thermal conductivity, and T is the temperature. The study focused on the doping mechanisms of ZnO with Aluminum, and then the thermoelectric properties of ZnO doped with aluminum by spark plasma sintering technique. For Al-doped ZnO, the spark plasma sintering technique used to prepare samples from precursors canceled at various temperatures. I take these samples for study for doping mechanism in different material. For Al, doped ZnO, the spark plasma sintering conditions together with the micro structural evolution and thermoelectric properties of the samples were studied in detail. Moreover, nano composite approaches have been used to study the thermoelectric properties of other material systems such as Zinc oxide and half-Heusler phases. We observed a significant improvement in peak ZT of nano structured n-type HH compound 0.8 to 1.0 respectively. Here we studied only n-type HH compounds. The improvement of figure of merit is mainly due to the reduction of thermal conductivity. This nanostructure approach is applicable to many other thermoelectric materials that are useful for automotive, industrial waste heat recovery, space power generation and many other fields.

Keywords

Heusier Phases, Doping Mechanism and Thermoelectric Devices.

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Rahul Agrawal ¹, B. N. Agrawal ², Vinod Sherawat ¹, K. P. Singh ²

Affiliations
1 NGFCET, Palwal (Haryana), IN
2 Delhi College of Technology and Management, Palwal (Haryana), IN

Abstract

Compression ignition engines have high thermodynamic efficiency therefore they have always been the first choice for heavy duty vehicles. However, future emission regulation poses a challenge for upcoming diesel engine combustion systems. Future emission regulations are becoming more restrictive, forcing engine designers towards lower exhaust emissions and better performance. The analysis is focused on direct injection Diesel engines, where the fuel-air mixing process plays a dominant role on engine performance. Only with a good understanding of these phenomena it will be possible to reduce the emission levels without impairing the engine performance and efficiency. all the four blends of hexane have higher value of ignition delay than the pure diesel for the entire range of temperature and also various pressures (10, 15, 20 and 25 bar). the variation of ignition delay for the Hexane blended diesel fuel with air temperature being varied from 583-663 K. The effect of percentage of n-hexane blends shows as increasing the percentage of n-hexane blends the ignition delay is also increased for pressure 10 to 25 bar. the variation of ignition delay of 20% and 30% DEE blends is much higher than the 10% and 20% DEE blends or 30% and 40% of DEE blends. In this case the percentages of blends of DEE is increases the ignition delay is decreased while the result is opposite in the n-hexane blends.

Keywords

n-Hexane, n-DEE, Blending, Ignition Delay.

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Pankaj Kumar Sharma ¹, B. N. Agrawal ¹

Affiliations
1 Department of Mechanical Engineering, Delhi College of Technology & Management, Palwal (Haryana), IN

Abstract

Cost of any component is earlier provided by the manufacturer only, but now a day cost of any component is given by market or we can say directly by user. All of this is because of competitive market and new technology. Now a days users give the target price and accordingly manufacturer planns material, process, etc. to meet the price. There are many types of components used to assemble an automobile like sheet metal components, rubber & plastic components, machined components of various parts. Here we report how to know the cost of a machined component.

Keywords

Machine Hour Rate, Procurement Cost and Wage of Operator.

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