Numerical and experimental studies of a capillary-tube embedded PCM component for improving indoor thermal environment

This paper aims to analyse the thermal characteristics of a novel system of Capillary Tubes embedded in a Phase Change Material (CT-PCM) as part of active building environmental design for energy conservation and the improvement of indoor thermal environment. The CT-PCM system is proposed based on the concept that low-grade energy utilisation potential could be harnessed and maximised by buildings’ radiant heating/cooling systems and phase change material. The CT-PCM component is first built in the laboratory, and the thermal characteristics of the CT-PCM are investigated through a set of thermal response experiments. In addition, a simplified model is developed to assess the long-term thermal performance of the CT-PCM system for its application during a strategical system design stage. To ensure the robustness of the numerical model in the assessment of the thermal performance of the system, the developed model is evaluated against the experiments under a set of dynamic thermal boundary conditions. The evaluation process revealed that when the flow rate of thermal fluids in the CT-PCM system is more than 800 ml/min, the simulation results of the proposed simplified model is in a good agreement with the experiment. When the flow rate in the capillary tube is smaller than 800 ml/min, the correction factors are derived to address the non-uniformity of temperature distribution

Analysis of waste thermal energy from banana peels using decomposition process for heat generation

Decomposition of biomass due to bacterial activity results in the release of energy and warming of the mass. Therefore, the heat produced from the decomposition can be exploited effectively through a construction of a heat exchanger system. The working principle for this system is similar to that of ground source heat pumps. However, the system uses heat released from decaying biomass instead of geothermal heat from the ground. The main objective of this experimental work is to evaluate the potential of designing a heat pump system utilising the heat recovered from banana peels as a source of energy. Theheat exchanger system consists of pipes with a circulating medium (water) running through the piles of decaying biomass to extract heat released during the decomposition process. A heat pump could also be applied to the heat exchanger to increase its efficiency. The amount of energy extracted from the system is given by the temperature difference of circulating medium between the inlet and outlet pipe of the system. This system will analyse and evaluate the dependence of heat release rate on temperature. Results obtained during experimental testing are presented and discussed here. The rate of heat extraction from the compost will be determined and analysed throughout the system. Heat exchanger system constructed from banana peels managed to secure an estimated amount of 3 to 4 watt heat power per kilogram dry matter

Renewable Energy Potential From Micro Hydro For Techno-Economic Uplift – A Brief Review

Modern world requires energy more than ever. As the global population and modernization exhibit seemingly ever upward trends, it is certain that the crave for energy will continue to rise. However, conventional energy is depleting at an alarming pace, though renewable energy seems to prospect a promising alternative. Being one of the more established and successful renewable energy technologies, the authors attempt to review the micro hydro as well as its potential in providing sustainable energy to the mankind