| Work Detail |
Developed by scientists in the Netherlands, the prototype heat battery consists of a potassium carbonate-based storage module and an electrically powered mechanical system that maintains continuous charge or discharge power.
A group of researchers led by the Eindhoven University of Technology (Netherlands) has developed a prototype solar-powered thermochemical storage system that stores thermal energy generated by solar thermal collectors.
The scientists pointed out that the novelty of their work consisted in using a novel methodology based on simulation to study the behavior of the new system in a rehabilitated house with an aerothermal heat pump and without gas supply.
"The proposed methodology integrates the simulation of the behavior of the building and a substitute model based on data, which allows optimizing the design of the system based on the specific requirements and characteristics of the building," they explained. "The reduction in imported electricity is an adequate indicator to assess the value that the system can bring to the homeowner."
The heat battery (HB) consists of a storage module based on potassium carbonate (K2CO3), which is one of the most promising thermochemical storage materials for applications in built environments, and an electrically driven mechanical system that maintains charging powers. or continuous download.
In charging mode, the thermal accumulator receives the inlet temperature and the mass flow rate of the charging fluid in the heat exchangers. At the same time, it adjusts the powers of the fan, the pump and other components. In discharge mode, the battery uses a similar set of input and output variables calculating the corresponding fluid outlet temperature, actual charge power, and electrical power.
"Once the charging or discharging process is complete, these components will turn off to put the thermal battery in standby mode when its heat loss is negligible," the scientists explain.
They assumed that the heat battery had a storage volume of 320 L or 93 kWh and that the solar collectors had a total area of ??8 m2. They also assumed that the heat pump had a rated heat output of 12 kW and a rated coefficient of performance (COP) of 4.0. The house is located in Eindhoven and has an annual electricity consumption of 9 MWh.
Through simulation, the group found that the novel battery is capable of “digesting” thermal energy from solar thermal collectors and reducing the households annual electricity consumption for heating by between 0.7 MWh and 1.0 MWh. It was also found that increasing the storage volume of the battery can reduce thermal comfort and that its optimal size should be between 80 L and 160 L.
“The result also suggests that it is not worth increasing the storage volume for seasonal storage in light of the limited space for both the heat coil and the solar collectors in a single-family home, especially when compared to the specific benefit of water tanks with the same storage volume”, concluded the academics. “All these results suggest that a small-scale HB might be more practical than a large-scale one in this type of daily storage use case due to the efficient use of both storage capacity and upload and download powers.”
The system was presented in the study “ A design optimization method for solar-driven thermochemical storage systems based on building performance simulation ”. , published in the Journal of Energy Storage . Scientists from the Netherlands-based thermal battery company Cellcius BV also participate in the research group. |
