Experimental Facility Supporting the EXCELLEND Project

An experimental facility combining a multi-source heat pump, hybrid thermal collectors, and geothermal energy for heating, cooling, and domestic hot water production in buildings is now available. Access to this pilot system has been granted to the EXCELLEND project, which includes a fully controllable solar-assisted heat pump for heating and cooling a building, developed within the H2020 project RES4BUILD. 

ΕXCELLEND will develop new control algorithms with “smarter” features to replace the existing rule-based control of this pilot system. The aim is to further enhance the flexibility and load shifting features with the use of the available buffer tanks and thermal inertia of the building. 

Aboout the experimental installation:

“Experimental facility of an energy system combining multi source heat pump with hybrid thermal collectors and geothermal energy for heating, cooling, and domestic hot water production in buildings”.

The experimental installation features a pilot energy system based on a multi-source heat pump (water/air) with a heating capacity of 15 kWth. The heat pump operates with the low-Global Warming Potential (GWP) refrigerant R454C and was developed within the framework of the research project H2020-RES4BUILD (GA nr. 814865). Its purpose is to produce hot/cold water and domestic hot water (DHW) in order to meet the energy demands of office and residential buildings. In addition to the heat pump, the system includes:

1. Four parabolic Hybrid Photovoltaic – Thermal Collectors (PVT) which simultaneously produce heat and electricity. The produced thermal energy can either assist the cold side of the heat pump (via a suitable storage tank) or directly meet the thermal loads for DHW production.
2. Three 400 l thermal storage tanks which introduce flexibility and functionality to the system. The first tank stores hot/cold water produced by the heat pump to meet heating/cooling needs. The second tank stores hot water from the PVT collectors, which can be supplied to the evaporator of the heat pump enabling a solar assisted mode. The third tank serves as a virtual geothermal heat exchanger (Borehole Thermal Energy Storage – BTES) with a controllable temperature, and is also connected to the evaporator of the heat pump, facilitating the simulation of a geothermal heat pump system.
3. A 300 l DHW storage tank. This tank is connected to both the hot side of the heat pump and the PVT collectors. It is also equipped with a heat dissipation system capable of simulating different consumption profiles.
4. Auxiliary components and automations, such as three-way valves, heat rejection systems, circulation pumps, and safety devices to ensure smooth operation and control of the system. Additionally, an external air-to-water heat pump is connected to the hybrid geothermal tank to regulate its temperature according to desired conditions.
5. Various sensors such as temperature sensors (PT100), pressure sensors (in the refrigerant circuit), solar radiation sensor (global and diffuse), water flow meters, and electricity consumption meter. All measuring instruments communicate with a central automation system based on a programmable logic controller (PLC). The control system enables full monitoring and adjustment in order to optimize various functions of the installation.