Technology Transfer Department

Application sectors

Problem to solve

These systems address the issue of circulating, heating, and cooling a thermal fluid to be inserted externally or internally into thermal storage modules for thermally charging or discharging them. The numerous thermocouples that can be applied to the modules or samples, combined with the possibility of different circulation modes through electrically actuated valves and flow meters, as well as the recording and control of data to be examined, allow for an effective thermal characterization of the medium under test.

Description

Solteca3 and ATES are two equipment of different size. As for Solteca3, there are two independent circuits: oil and cooling air. The oil circuit supplies thermal energy to the storage module; the second one, on the other hand, allows to extract heat from the module. The circuit uses as HTF, a low environmental impact thermal oil, with a maximum operating temperature of 330°C (for low steam pressure (2.5 kPa)). This facility includes heat exchangers, and all the circuit components required to characterize thermal storage modules. The mass flow's operative range is between 0 and 1500 kg per hour. An electric heat exchanger (25 kWth) heat-ups the oil flow to the target temperature of the storage inlet, while an air cooler cools down the oil at the exit of the storage module to simulate the thermal user. In the oil circuit, 4 electro-valves allow to set the oil circulation, according to the different operating phases: heating, cooling of the oil, charging, discharging of the TES module. In charging, the oil, leaving a buffer tank, is sent to the heat exchanger, where it is warmed up to the target temperature, and then is sent to the storage module. The oil, circulating inside the module heat exchanger, transfers thermal energy to the storage medium (i.e. concrete or PCM), and then is recycled back to the tank. In the discharging phase, the thermal energy stored in the heat storage medium is released to the oil: the direction of oil circulation into the module can reverse and the module is cooled down through the oil passing the air cooler. The plant has 4 electrovalves, a Coriolis flowmeters, a magnetic pump and about 40 thermocouples. ATES is similar but smaller; circulation, heating and cooling of the thermal fluid is performed by a 3 kW commercial circulator. The heating can be executed also by Joule effect, the flowmeter is a rotameter, and the fluid modulation, differently from Solteca3, is not allowed.The control of both plants can be carried out also in remote.

Research group involved