Experimental Investigation of a thermoelectric generator

• Main Author: Ke, Shaohui.
• Other Authors: Leong Kai Choong
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mechanical engineering::Alternative, renewable energy sources
• Online Access: http://hdl.handle.net/10356/53589
• Institution: Nanyang Technological University

Thermoelectric power generation converts heat into electrical power. The thermoelectric effect was discovered back in the 1800s but had only gained significant interest in recent years due to technological advancements in the semiconductor industry and the need to find renewable sources of energy. Despite this, thermoelectric power generators are not commercially viable due to the low efficiencies (electrical power output over heat input) of the materials. In the search for better thermoelectric materials, a clearer understanding of the impact of the various effects on the amount of heat input and electrical power output has to be established. This project was divided into two parts. The first part was to evaluate the performance of the thermoelectric generator and verify data obtained previously with the same rig. The results showed similar trends to previous data but yield lower efficiency. The discrepancy was found to be due to lower Seebeck coefficient of the new thermoelectric element. The second part investigated the effect of transient heat input as well as effects of heat recovery on the efficiency of thermoelectric generator. Heat input to the module was raised and lowered to the initial heat input periodically. It was found that the time-averaged efficiency was approximately 1.78% and would lean towards the efficiency of the heat input at which it spent more time on. It was also discovered that heat recovery by the thermoelectric module momentarily increase the efficiency of the thermoelectric generator by a huge margin. The maximum heat recovery efficiency obtained was approximately 7.4%. The results from these experiments show potential in using thermoelectric module in transient heating environment but more experimentation needs to be conducted to provide a more definitive verification and before a firm conclusion can be made.