Zuryati Djafar

The Utilization of Heat Pipe on Cold Surface of Thermoelectric with Low-Temperature Waste Heat

Thermoelectric (TE) modules are a thermo-element device that can harness the heat and convert it into electrical energy. As an electrical generator system, TE has several advantages i.e not noisy, easy maintenance, relatively small, lightweight and environmentally friendly because it does not produce pollution. In this paper, the research about the performance of TE modules that used for electric generator has been done. TE modules utilize low temperature waste-heat from a solar cell that simulated with a combination of a bulb and a collector plate. TE modules which tested are single and double modules, in which for double modules, connectivity Thermal-Series was used. Parameters of performance such as output power generated are determined by measuring the temperatures difference and the voltages difference at the test module as well as using several equations. The results show that the distance of heat source and load applied will greatly affect the performance of thermoelectric generator (TEG) modules. The results showed that the number of modules and loading will greatly affect the performance of TEG modules. The use of heat pipes generate a far greater power 4-6 times on the single TE Module (0.84 mW) than without heat pipe (0.14 mW), and a double TE modules that uses heat pipe will became 4 times larger (1.48mW) than without heat pipe (0.37mW).

Analysis of Chemical and Physical Properties of Biochar from Rice Husk Biomass

Chemical and physical properties of Rice Husk as a potential energy resource were analyzed by means Fourier transform infrared (FTIR), x-ray diffraction (XRD), scanning electron microscope (SEM), and energy disperse spectroscopy (EDS). Rice husk is heated with varied temperature of 250°C, 350°C, 450°C and 30, 60, 90 minutes respectively combine with time variation. The results show that the calorific value decreases whenever the temperature and time increase. The heating time of 30 minutes at 250 °C of temperature gives calorific value of 10.4 MJ/Kg. While at the 450°C of temperature, the calorific value decrease to 4.7 MJ/Kg. The EDS shows that the time of heating is an important parameter where carbon and nitrogen were decreasing with the increment of the heating time while the oxygen increase when the heating time increase. The XRD shows that the broad (002) reflections between 20° and 30° indicate carbon disordered with small domains of coherent and parallel stacking of the graphene sheets, which consists of surface morphology from SEM. FTIR shows that the O-H stretching pronounced at around 3452 cm−1 and 3412 cm−1 and pronounced clearly at the highest temperature. The aromatic group from lignin gives rise to C=C asymmetric stretching at cm−1 as a G band corresponds to the sp2-hybradization bonding of carbon atoms and C-H bending modes at 2927 at 796 cm−1. This results of the characteristic of chemical and physical properties of the rice husk examination provide the prominent source of useful energy that can eventually replace the fossil fuel.

Experimental Study of Heat Transfer Characteristics of Condensed Flow on the Vertical Wave Plates

Studies on the heat transfer characteristics of vertical wave plate subjected to the condensed steam had been done. This research was done to know temperature distribution profiles and heat transfer coefficient on wave plates in vertical position. Temperature profiles were obtained by measuring directly the temperature of test section. On the other hand, determination of heat transfer coefficient was done by using Von Karman’s equation that based on temperature profile.