A system simulation framework has been further developed in python to build, run and process TRNSYS simulations. This python package has been made available in GitHub for the TRI-HP partners and it will be open to the general public during summer 2020 (
https://pytrnsys.readthedocs.io/en/latest/(s’ouvre dans une nouvelle fenêtre))
A stakeholder process was carried out to better understand the conditions of market uptake of innovative heat pump systems in different European countries. The objective was to investigate key social and contextual factors that influence the social and market acceptance of renewable heating and cooling systems. The analysis included a literature review and in-depth interviews and stakeholders workshops with change actors in the heat pump markets in Germany, Switzerland, Spain and Norway. Among others, the perspective of heat pump manufacturers, HVAC planners, installers and building owners were taken into account. As a result, we could identify important barriers, drivers and incentives for the adoption of heat pump systems in general and innovative trigeneration heat pumps systems. Besides economic factors, such as high upfront costs, issues of practical implementation and feasibility emerged as important topics. Organisational factors, such as the cooperation between different trades on the construction site, or country specific heating cultures also turned out to be important issues.
We have developed three innovative heat exchangers:
• A compact and reliable supercooler (evaporator) for a heat pump for the solar ice-slurry system.
• A compact, highly-energy-efficient tri-partite gas-cooler as a single unit for a CO2 heat pump. Three heat exchangers were used with an 86 % reduction of weight (5 kg) compared to the 34 kg necessary with an helical counter-flow.
• A compact, highly-energy-efficient dual-source heat exchanger as a single unit for a propane heat pump with a direct heat exchange between brine/air and refrigerant.
Three natural refrigerant heat pumps were designed, manufactured and experimentally assessed. Two of them were designed using propane and one using CO2. One propane unit was using the dual source/sink evaporator/condenser. The other propane unit and one CO2 heat pump used the supercoolers with the icephobic coatings developed within the project. Moreover, the CO2 unit included the tri-partite gas cooler also developed within the project.
An efficiency drift self-diagnosis algorithm for the heat pumps to facilitate maintenance and increase reliability was developed and tested using experimental data of one of the propane heat pumps.
Besides this, an optimal advance energy management (AEM) system algorithm to minimize the energy cost and increase the renewable share was developed based on Model Predictive Control (MPC). The potential benefits of the AEM system was first assessed by means of simulation using different scenarios and conditions in a realistic setup using the pytrnsys simulation environment. Afterwards the AEM was implemented in a hardware and tested in the hardware-in-the-loop system test with a complete system.
Using the hardware-in-the-loop Concise Cycle (CCT) Test, we have demonstrated the autonomous operation of the complete TRI-HP systems in a relevant environment using the accelerated hardware-in-the-loop approach, including the integration of both thermal (heat pump, storage tanks, hydraulics and control) and electrical elements (battery, inverter, PV).
The cost-competitive advantage of solar-ice slurry TRI-HP systems over the conventional solar-ice with a synthetic refrigerant has been proven.
