• Energy Research

This study provides a techno-financial evaluation of two sites in Malaysia: Kudat, located on the coast of the northernmost part of Sabah, the state of East Malaysia with promising wind potential, and Putrajaya in the Klang Valley region with moderate wind potential at high elevations similar to the dominant cities in Malaysia. Three small-scale wind turbines were evaluated, taking into account a nominal electrical power generation below 100 kW. The research is focused on 220 residential households. The software used to perform the evaluation was Hybrid Optimization of Multiple Energy Resources (HOMER). The research novelty is the examination of the non-hybrid small-scale turbines at high elevations for regions with low wind speed, such as Malaysia. Regardless of the wind farms’ financial profit, this study used the net present cost (NPC) analysis in all cases. This research demonstrates the feasibility of small-scale wind turbines mounted at high elevations for generating sufficient energy. The results indicate that in both areas, the RX-20KH3 model is the best option, and the costs of the FH-5000 and RX-20KH3 farms are proportionate for a renewable project. Furthermore, with government support, the WES80 farm could be suitable.

Studied performance of triangular grooved microchannel heat sink (TGMCHS) using nanofluid.Solved 3D laminar flow and conjugate heat transfer of TGMCHS using FVM.Investigated the effect of geometrical parameters, nanofluid type, and its concentration.Analyzed the effects of particle diameter, base fluid, Reynolds number.TGMCHS efficiency is increased by 179.55% compared to simple MCHS. A numerical simulation is conducted to examine the heat transfer and fluid flow characteristics of nanofluids in a triangular grooved microchannel heat sink (TGMCHS). The governing and energy equations are solved using the finite volume method (FVM). The influence of the geometrical parameters such as the angle (50-100?), depth (10-25µm) and pitch (400-550µm) of the groove on the thermal performance of TGMCHS was examined. The effects of different nanoparticle types (Al2O3, CuO, SiO2, ZnO), volume fraction (O=0.01-O=0.04), particle diameter (25-80nm) and base fluid (water, ethylene glycol, engine oil) at different Reynolds numbers are also studied. The thermal performance of TGMCHS had significant increment with the increment of angle and depth of the groove accompanied with an optimum groove pitch. It is found that the TGMCHS thermal performance of using Al2O3-H2O (O=0.04, dnp=25nm) is outperformed the simple MCHS using water.

Radiant cooling systems (RCS) are gaining acceptance as a heating, ventilation, and air conditioning (HVAC) solution for achieving adequate thermal comfort and maintaining acceptable indoor air quality inside buildings. RCS are well known for their energy-saving potential; however, serious condensation problem hinders the growth of this technology. In order to prevent the risk of condensation, the supply water temperature is kept higher than the dew point temperature of the air inside the room. The full potential of the cooling power of a radiant cooling panel is limited. Therefore, this article is on maximizing the cooling capacity of a radiant cooling panel, in terms of flow configuration. Radiant cooling panels (RCP) with different chilled water pipe configurations are designed and compared, side by side with the conventional serpentine flow configuration. The cooling performance of the radiant cooling panels is evaluated by using computational fluid dynamics (CFD) with Ansys Fluent software (Ansys 2020 R2, PA, USA). Under similar flow and operating conditions, the common serpentine flow configuration exhibits the least effective cooling performance, with the highest pressure drop across the pipe. It is concluded that the proposed designs have the potential of improving the overall efficiency of RCP in terms of temperature distribution, cooling capacity, and pressure drop.

A numerical investigation is performed to study the thermal and flow fields in a trapezoidal grooved microchannel heat sink (TGMCHS) using nanofluids. The governing and energy equations are solved using the finite volume method. The influence of the geometrical parameters such as the width, depth and pitch of the groove on the thermal performance of TGMCHS was examined. The effects of different nanoparticle types, volume fraction, particle diameter and base fluid at different Reynolds numbers are also studied. It is found that the increment of the maximum width ‘a’ and reduction of the minimum width ‘b’ of the trapezoidal groove gives the maximum thermal performance and this implies that the triangular shape would be favorable compared to rectangular shape MCHS. It is inferred that Al2O3–H2O had the highest thermal performance with 0.04 volume fraction and 25 nm particle diameter.