A Study on the Performance of 100 W Thermoelectric Power Generation Module for Solar Hot Water System

태양열 온수 시스템에 적용 가능한 100 W급 열전발전 모듈 성능에 관한 연구

Abstract

Solar hot water system produces hot water using solar energy. If it is not used effectively, overheating occurs during the summer. Therefore, a lot of research is being done to solve this. This study develops thermoelectric power module applicable to solar hot water system. A thermoelectric material can directly convert thermal energy into electrical energy without additional power generation devices. If there is a temperature difference between high and low temperature, it generate power by Seebeck effect. The thermoelectric module generates electricity using temperature differences through the heat exchange of hot and cold water. The water used for cooling is heated and stored as hot water as it passes through the module. It can prevent overheating of Solar hot water system while producing power. The thermoelectric module consists of one absorption and two radiation part. There path is designed in the form of a water jacket. As a result, a temperature of the absorption part was $134.2^{\circ}C$ and the radiation part was $48.6^{\circ}C$. The temperature difference between the absorption and radiation was $85.6^{\circ}C$. Also, The Thermoelectric module produced about 122 W of irradiation at $708W/m^2$. At this time, power generation efficiency was 2.62% and hot water conversion efficiency was 62.46%.

Fig. 1 Schematic diagram of solar hot water system

Fig. 2 Schematic diagram of system operating according to setting mode

Fig. 3 Double vacuum type solar hot water system

Fig. 4 Picture of hot & cool side block and thermoelectric module

Fig. 5 Picture of thermoelectric module

Fig. 6 Picture of solar hot water system and thermoelectric module installed in control room

Fig. 7 Temperature of working fluid, hot water, hot side block and cool side block (at average ambient temperature 14.8℃, date 2017. 11. 11)

Fig. 8 Experimental result of thermoelectric module (at average ambient temperature 14.8℃, date 2017. 11. 11)

Table 1 Specification of solar hot water system

Table 2 Specification of thermoelectric element (TGM-127-2.0-1.3)

Table 3 Design condition of thermoelectric module

Table 4 Ambient temperature (at date 2017. 11. 11)

Table 5 Experimental results of thermoelectric module using solar collector (at date 2017. 11. 11)