Experimental Investigation of Off-Grid Solar Thermal Water Heating System Integrated with Thermal Energy Storage /

Abstract

Using renewable energy sources to harvest energy is a priority in current era for energy production sector. In various applications, the latent heat thermal energy storage systems got a good response for the solar energy storage. An off grid Solar Thermal Water Heating (STWH) system using a custom-build latent heat storage tank with paraffin wax as Phase Change Material (PCM) is designed, developed and evaluated in real-time. The paradigm shift of energy markets from conventional energy sources to renewable energy sources of production has created an increased demand for the creation of efficient energy storage systems to overcome the sustainability challenges. To increase the overall efficiency of thermal energy storage systems, different experiments has been performed to find out best parameters on which the heat transfer is maximum. The experimentation is run on different flow rates. For PCM selection different PCM characteristics has been studied. Fatty acids-based Phase change materials (PCMs) are regarded as one of the most promising candidates to store and release large amounts of latent heat, but they offer low thermal conductivity cause to limits its applications. Paraffin waxes are also the most common PCM for electronics thermal management because they have a high heat of fusion per unit weight, have a large melting point selection, provide dependable cycling, are non-corrosive and are chemically inert. The chemical structure characterization and thermal stability of PCMs were performed using Thermal Gravimetric Analysis (TGA). The thermal characteristics of charging and discharging processes and thermos-physical properties were studied using the Differential Scanning Colorimetry (DSC). The results obtained from DSC Method are compared with literature. A good agreement is found. The experimental results yielded by utilizing both the techniques showed that the thermal conductivity of the PCM is comparatively near to similar. From the findings, it can be concluded that paraffin wax is very suitable candidate for domestic heating purposes. The findings revealed that the performance provided by the Paraffin wax is good, storing 2.1 MJ.kg of energy having 83.02% thermal efficiency and 0.69 ERR.