A dedicated lab space of 150 m2 comprises three world-class hydraulic testing loops to determine the behaviour of thermal energy storage systems of all sizes (Typically 1-3m3) under different heat transfer fluids (air, oil or steam), heating/cooling rates, high temperatures (up to 800°C) and/or heating/cooling thermal cycles in a controlled laboratory environment.

Thermal loop, consisting in a closed hydraulic loop using thermal oil as heat transfer fluid, able to deliver hot oil up to 400˚C and variable mass flow up to 25m3/h. The facility comprises a 40 kW heater, 100 kW heat exchanger, automatic three-way valves and a complete set of high-precision measuring instruments. The facility is prepared to insert any type of testing specimen in the hydraulic loop and subject it to the desired conditions. The system is controlled by remote by means of Labview software which provides a programmable environment for testing that can include automatic thermal cycles, consisting in heating and cooling steps with their corresponding heating and cooling rates and mass flows. The system allows as well to automatically change the direction of the oil flow.

Thermal loop, consisting in a closed hydraulic loop using air as heat transfer fluid, able to deliver air from room temperature up to 800˚C and variable mass flow up to 360 kg/h. The facility comprises a 100 kW heater, automatic three-way valves and a complete set of high-precision measuring instruments. The facility is prepared to insert any type of testing object in the hydraulic loop and subject it to the desired conditions. The system is controlled by remote by means of Labview software which provides a programmable environment for testing that can include automatic thermal cycles, consisting in heating and cooling steps with their corresponding heating and cooling rates and mass flows. The system allows as well to automatically change the direction of the air flow.

Services offered by the Thermal loop infrastructure and its research environment:

Determining the behavior of components and thermal energy storage systems under different heating/cooling rates, high temperatures and/or thermal cycles in a controlled laboratory environment at a relevant scale. Important operation parameters such as energy storage density, thermal charge/discharge power, efficiency, structural and mechanical resilience as well as their evolution under

numerous thermal charging and discharging cycles at almost real operating conditions may be measured and studied.

The infrastructure allows to test the behavior of any type of thermal energy storage technology under different heat transfer fluids, namely air, thermal oil and steam.

The thermal loops have been of paramount importance in the validation of two thermal energy storage technologies which subsequently have been upscaled in real industrial sites, namely a Concentrated Solar Power Plant in Morocco and in a steelmaking industry in Spain. The thermal loops are involved in 3/4 projects per year, out of which 1/2 belongs to international contracts.