Muhammad Fairuz Remeli

Experimental Investigation on the Effect of Orifice Diameter and Inlet Pressure to the Ranque-Hilsch Vortex Tube Performance

In this experiment, the cold mass fraction, cold temperature difference and isentropic efficiency of Ranque-Hilsch Vortex Tube were investigated and measured. Three different inlet pressures (absolute) (296633 Pa, 394699.5 Pa and 492766 Pa) and 2 type of orifice diameter (4 mm and 5 mm) were used. 5 mm orifice gives higher value of cold mass fraction (μc = 0.7067) compare to 4 mm orifice (μc = 0.3264). It is also no significant effect in cold mass fraction by changing three difference inlet pressures. 4 mm orifice has higher cold temperature difference (ΔTc = 18°C) compare to 5 mm orifice (ΔTc = 8°C) at highest inlet pressure (492766 Pa) that were used. 4 mm orifice has higher isentropic efficiency (ηisen=0.17545) compare to 5 mm orifice (ηisen=0.0834). For both orifices, the highest isentropic efficiency was obtained when the lowest inlet pressure (296633 Pa) were applied.

Experimental investigation on the effect of conical valve shape and swirl generator to the performance of Ranque-Hilsch Vortex Tube

Temperature at cold outlet, cold mass fraction and isentropic efficiency in the Ranque-Hilsch Vortex Tube (RHVT) are experimentally measured and derived. For the experiment, different pressures (absolute) (between 290 to 800 kPa) were applied as source, 3 types of swirl generator and 3 shapes of conical valve were used. The lowest temperature obtained during the experiment was -11.6 for a cold mass fraction (μ_c = 0.947) which gave the highest isentropic efficiency (η_is= 0.336) at source pressure of 790.2 kPa. However, the highest cold mass fraction (μ_c = 1.024) was given by source pressure of 790.2 kPa with isentropic efficiency (η_is) of 0.042 and the cold temperature was 20°C.

Experimental Investigation on Effect of Adhesives on Thermoelectric Generator Performance

Thermoelectric generators (TEGs) convert heat energy into electricity. Currently, these devices are attached to heat exchangers by means of mechanical devices such as clamps or fixtures with nuts and bolts. These mechanical devices are not suitable for use in harsh environments due to problems with rusting and maintenance. To eliminate the need for such mechanical devices, various kinds of adhesives used to attach thermoelectric generators to heat exchangers are investigated experimentally in this work. These adhesives have been selected based on their thermal properties and also their stability to work in harsh environments to avoid damage to the integrity of the attachment over long periods of time. Stainless-steel plates were attached to a thermoelectric generator using the adhesives. The introduction of the adhesive as a means of attachment for thermoelectric generators contributes to increase the thermal resistance to heat transfer across the TEG. The adhesive layers increased the thermal resistance of the thermoelectric generator by 16% to 109%. This work examines the effect of the adhesives on the thermal performance and power output of a single thermoelectric generator for various heat inputs.

Experimental Analysis of Thermoelectric Heat Exchanger for Power Generation from Salinity Gradient Solar Pond Using Low-Grade Heat

Salinity gradient solar ponds act as an integrated thermal solar energy collector and storage system. The temperature difference between the upper convective zone and the lower convective zone of a salinity gradient solar pond can be in the range of 40–60°C. The temperature at the bottom of the pond can reach up to 90°C. Low-grade heat (<100°C) from solar ponds is currently converted into electricity by organic Rankine cycle engines. Thermoelectric generators can operate at very low temperature differences and can be a good candidate to replace organic Rankine cycle engines for power generation from salinity gradient solar ponds. The temperature difference in a solar pond can be used to power thermoelectric generators for electricity production. This paper presents an experimental investigation of a thermoelectric generators heat exchanger system designed to be powered by the hot water from the lower convective zone of a solar pond, and cold water from the upper convective zone of a solar pond. The results obtained have indicated significant prospects of such a system to generate power from low-grade heat for remote area power supply systems.

Passive flow heat exchanger simulation for power generation from solar pond using thermoelectric generators

Renewable energy is becoming an important source of energy due to the rise in crude oil prices and the increase in greenhouse effects due to burning of fossil fuels. With only finite source of fossil fuel and exponential increase in the demand of power be

Experimental Investigation of Orifice Diameter, Swirl Generator and Conical Valve Shape to the Cooling Performance of Ranque-Hilsch Vortex Tube

This paper is about experimental investigation of the orifice diameter, swirl generator and conical valve shape influence the cooling performance of Ranque-Hilsch vortex tube. From the experiment, its shows that conical valve shape has smallest effect on cooling performance (0.124) of the Ranque-Hilsch vortex tube. It also revealed that swirl generator gave the greatest (0.336) effects to the cooling performance of Ranque-Hilsch vortex tube and have the highest range of difference cooling performance (0.027 to 0.229) compare to conical valve shape (0.073 to 0.087) and orifice diameter (0.009 to 0.012).

The effect of cross-head velocity and length of tube on energy absorption of aluminium tube

The objective of this study is to investigate the effect of variation of the tube length and the crosshead velocity on the amount of energy absorption of aluminium tubes (Al 6061) towards the inversion collapsed mode. The tests were performed on the Aluminium tubes using compression test apparatus according to ASTM E8 standard procedures. Two parameters that are included in the experiment were the crosshead velocity and tube length. The collected experimental data were organized and analysis of energy absorption was performed. Comparison was made to the values of energy absorption obtained from the experiments, and it was found that the energy absorbed by the Aluminium tube was increased by increasing the tube length as well as crosshead velocity.