Energy recovery from domestic radiators using a compact composite metal Foam/PCM latent heat storage

Abstract

With the increasing demand for energy consumption in domestic buildings and consequent CO 2 emission, there is a need to provide proper products to reduce energy loss. Domestic radiators for space heating can be improved by using a Compact Latent Heat Storage (CLHS) unit mounted on the wall side surface in order to offer energy saving and peak-shaving. The unit offers the potential to save otherwise wasted energy from the back surface of the radiator to the walls in the charging mode of the energy storage system. When the heating system is turned off, the CLHS unit discharges the stored heat towards the room to provide a uniform temperature on the surface of the radiator. An aluminium foam embedded inside the bulk Phase Change Material (PCM) can modify the heat storage/retrieval rate. A PCM is selected depending on the radiator's surface temperature, which is almost equal to the hot water temperature delivered to the radiator. Different metal foam porosities are examined and compared with the PCM-only alternative (i.e. without metal foam enhancement). The results show the porous-PCM CLHS alternative provides an almost constant temperature during the discharging process equal to 54°C. However, for the PCM-only alternative, the temperature of the surface reduces continuously. Using the porous medium results in a shorter melting time, about 95% of what is needed for the PCM-only alternative. Increasing the metal foam porosity results in shorter charging/discharging time; however, since the surface temperature of the porous-PCM unit is almost constant for different metal foam porosities, a system with higher porosity (97%) is desirable.

Phase Change Materials for Renewable Energy Storage Applications

“…Now days, utilization of fossil fuels creates huge impact on environment and its leads to studies on commercial refrigeration, heating and cooling in building, solar heating and electronics, Textiles, building energy conversation etc. The PCMs operating temperature range from +40°C to +80°C are used for solar based heating, hot water production and electronic applications and + 80°C to +1200°C range is applied for absorption cooling, waste heat recovery and concentrated solar [44][45][46][47][48][49].…”

Construction strategies and thermal energy storage applications of shape‐stabilized phase change materials

“…Besides, porosity can also affect the properties of metal foambased PCMs. Sardari et al 118 investigated the effect of porosity of aluminum foam in PCMs/aluminum foam composites on the performance of domestic radiators. The compact latent heat storage (CLHS) unit at the backside of the radiator is shown in Figure 8a.…”

“…Other F I G U R E 8 (a) Schematic of the compact latent heat storage unit at the back of the radiator, (b) the variation of PCMs average temperature in terms of time for different cases in the discharging process. 118 (c) Schematic diagram of copper foam. 119 (d) Schematic of boundary conditions of the model.…”

Influence of the Fin Shape on Heat Transport in Phase Change Material Heat Sink with Constant Heat Loads

“…Another way to augment the energy transport and to speed up the melting or solidification process is the use of metal foams [32][33][34][35][36]. The significant attenuation of natural convection is neutralized by the high heat conductivity of the foam.…”