The development of waste heat energy conversion device to generate electricity through hermoelectric generator (TEG) apply to LPG cookstove

Abstract

This research aims to develop the waste heat energy conversion device to generate electricity through a thermoelectric generator (TEG) which is called “CHEU. This device is applied to the LPG cookstove that serves as a waste heat source. The thermoelectric generator with 4 modules in series connection is used to convert heat energy to electricity. The present research shows a modification of the CHEU based on two concepts as follows: (1) re-design the structure for heat transfer improvement, and (2) select the high capability of TEG to support a high temperature from a heat source as a result of (1). In this study, the modified CHEU is called “MCHEU”. A heat-load condition is set as the gas pressure of LPG, which varies in a range of 0.1 - 0.6 kg/cm2, and the throttle valve is fixed approximately at 40% of a fully opened throttle, while the air entrainment is fully opened throttle. Also, the water-cooling system is used for heat dissipation. Base on the performance evaluation of MCHEU, the interesting results are drawn as follows: 1) the maximum temperature difference is on an average value of 278.5oC at a maximum heat load condition, while a maximum voltage, current, and power are on an average value of 18.83 V, 5.67 A, and 107 W, respectively. 2) The temperature difference of MCHEU is higher than that of CHEU with an average value of 50%. 3) The output power obtained by MCHEU is higher than that of CHEU with an average value of 52% and takes less time about 40% for fully charging a battery (12V 7.5Ah). Nevertheless, MCHEU usage does not affect the thermal efficiency of a cookstove. 4) The efficiency of an energy conversion obtained by MCHEU is 20%, which is higher than that of CHEU about 2%.