Prototyping a novel lab-scaled high temperature heat pump connected to a latent thermal energy storage for usage in thermally integrated Carnot batteries
Carnot Batteries integration in industrial processes can allow energy storage for damping renewable energies' intermittent production while increasing energy efficiency and decreasing greenhouse gases emissions. In the meantime, small scale High-Temperature Heat Pumps (HTHPs) are highlighted as promising to decrease usage of fossil fuels in small industrial applications. The SEHRENE (Store Electricity and Heat foR climate Neutral Europe) EU-funded project aims to develop a concept of Thermally Integrated Carnot Batteries (TI-CB) through modelling activities on three use cases and through the construction of a prototype, notably. This prototype will mimic one of the use cases representing the most the SEHRENE TI-CB concept. It will be spatially separated in two distinct test rigs, with the HTHP + Thermal Energy Storage (TES) being built at the University of Liège. The TES will be latent-type, filled with phase change material (erythritol, Tmelting = 117°C). The thermal power and temperature level of the test rig were chosen from components availability and literature review as being 10 kW of heating capacity and 135°C of condensing temperature. The HTHP will comprise an evaporator, a condenser, an internal heat exchanger, an expansion valve and two piston compressors. One of the latter will allow studies on compressor cooling, and the other will be used to run the general HTHP coupled with TES. Their role is distinct and they are not meant to run at the same time. A secondary pressurised water loop will be placed between the HTHP and the TES to address manufacturing constrains. It will include a feature to flash the water to allow TES charging both with liquid or two-phase water. The learning outcomes from that test rig to be built could be useful to both small scale machines and for upscaling, studying the dynamics of the test rig, the control strategies, and the compressor cooling.