Natural gas fired Combined Cycle (CC) power plants are currently the backbone of EU electrical grid, providing most of regulation services necessary to increase the share of non-programmable renewable sources into the electrical grid. As a consequence, Original Equipment Manufacturers (OEMs) and Utilities are investigating new strategies and technologies for power flexibility. On the other hand, existing cogenerative CCs are usually constrained by thermal user demand, hence can provide limited services to the grid. At the same time, CHP plants are highly promoted for their high rate of energy efficiency (> 90%) and combined with district heating network are a pillar of the EU energy strategy. To un-tap such unexploited reserve of flexibility, and to further enhance turn-down ratio and power ramp capabilities of power oriented CCs, this project proposes the demonstration of an innovative concept based on the coupling of a fast-cycling highly efficient heat pump (HP) with CCs. The integrated system features thermal storage and advanced control concept for smart scheduling. The HP will include an innovative expander to increase the overall efficiency of the HP. In such an integrated concept, the following advantages are obtained: - the HP is controlled to modulate power in order to cope with the CC primary reserve market constraints; - the high temperature heat can be exploited in the district heating network, when available; low temperature cooling power can be used for gas turbine inlet cooling or for steam condenser cooling, thus reducing the water consumption; - in both options, the original CC operational envelope is significantly expanded and additional power flexibility is achieved. In general, the CC integration with a HP and a cold/hot thermal storage brings to a reduction of the Minimum Environmental Load (MEL) and to an increase in power ramp rates, while enabling power augmentation at full load and increasing electrical grid resilience and flexibility.

The project aims at moving technological frontiers for low-emission combustion of hydrogen to fuel modern gas turbines at high firing temperatures and pressures, beyond the latest state-of-the-art. This will be achieved whilst maintaining high engine performance, efficiency, fuel and load flexibility, without diluents. At the same time, all emission targets set by the Clean Hydrogen JU Strategic Research and Innovation Agenda (SRIA) will be met. The idea is based on a proprietary combustion technology, designated constant pressure sequential combustion (CPSC) already deployed into the GT36 H-class engine (760 MW in combined cycle). The CPSC concept, based on a unique longitudinally staged combustion system, yields the best fuel flexibility and has the greatest potential to achieve the project target of demonstrating stable and clean combustor operation with concentrations of hydrogen admixed with natural gas, up to 100%, at firing temperatures typical of modern H-Class engines. The new, improved combustor design will be fully retrofittable to existing gas turbines, thereby providing opportunities for refurbishing existing assets. The primary objective is to demonstrate the CPSC technology in engine relevant environment (TRL6) in three steps (70, 90 and 100 vol% H2). In this pursuit, a subset of specific performance data (KPIs) will be met within the project timeline and with the planned resources and allocated budget. The project uses state-of-the-art computational tools, analytical modelling, and diagnostic techniques to investigate static and dynamic flame stabilisation. Testing is performed at world-class laboratories in test campaigns at reduced scale and in full size (at atmospheric and pressurised conditions). In preparation for commercialisation, the project will also develop a roadmap towards deployment of the developed system into operation and demonstration into a power plant environment quantifying the valuable contributions to the EU Green Deal.

The energy sector accounts for two thirds of the global CO2 emissions and is therefore crucial to ensure future green growth and to achieve the global emission reduction targets. Substantial reduction of CO2 emissions can only be achieved by large scale deployment of renewable energy sources, including in particular the most abundant energy sources, wind and sun. Their intermittent nature however poses significant challenges for the energy system as peak demand from the system and peak production form those intermittent sources do not overlap. As there are no large scale storage solutions available yet, other backup capacities are needed. The installed fossil capacity is large enough to provide this back-up power. However, the plants were designed for baseload operation, which results in increased wear and costs through cyclic operation and unnecessarily high emissions in the start-up phase. Providing technology upgrades to retrofit the installed power plants to enable flexible operation without penalties on life, cost and emissions is an opportunity to quickly provide the necessary backup capacity to keep the energy system stable and resilient and at the same time enabling higher renewable shares. TURBO-REFLEX will follow this approach and has selected technologies for retrofitting critical parts of thermal power plants which have already seen experimental proof-of-concept and are expected to significantly contribute to flexible operation. The technologies will reduce the minimum load, increase the ramp rates and reduce the costs per cycle. This will be achieved by new compressor designs for off-design operability, technologies in the hot gas path, in combustor and turbine, and by new materials, models and sensors to monitor and ensure the mechanical integrity in flexible operation. An integrated assessment will provide not only the technological but also the economic benefits for plant operators, thus ensuring a swift implementation of TURBO-REFLEX technologies.