This article introduces to the idea to deploy offshore power hub platforms with connected floating wind turbines, including short-term (battery) energy storage on the platform and long-term (hydrogen) energy storage located subsea. These energy hubs can provide low-carbon heat and electric power to...
This paper presents an approach for calculating optimized operating conditions in hybrid AC/DC systems while considering constraints on the small-signal dynamics. The implementation is based on a closed form power flow optimization considering the steady-state operating conditions and the damping of...
Entrained flow gasification of biomass provides the opportunity to convert low-grade biogenic feedstocks to high-grade synthetic fuels. For a top-fired entrained flow slagging biomass gasifier, the thermophysical properties of the ash and slag limit process operation and affect process energy...
Refrigeration systems in industrial food processing plants are large users of electric energy and often show high peak power consumption. Cold thermal energy storage (CTES) technology integrated into refrigeration systems can reduce the peak power requirement and achieve peak shifting by decoupling...
District heating systems based on industrial waste heat play an important role in using energy efficiently. Combined with a thermal energy storage technology, such as pressured-water tanks, they have the potential of significantly reducing greenhouse gas emissions as well. However, installing...
Power- and biomass-to-liquid fuel processes (PBtL) can utilize renewable energy and residual forestry waste to produce liquid synthetic fuels, which have the potential to mitigate the climate impacts of the current transportation infrastructure, including the long-haul aviation sector. In a previous...
In this paper, the impact of forced cooling on the dielectric recovery of ultrahigh pressure nitrogen arc is experimentally investigated. The dielectric recovery is studied by applying 10-kV high voltage pulse at different instances after current zero. The current amplitude and the half cycle...
Fluids confined in small volumes behave differently than fluids in bulk systems. For bulk systems, a compact summary of the system's thermodynamic properties is provided by equations of state. However, there is currently a lack of successful methods to predict the thermodynamic properties of...
For a long time, shell-and-tube heat exchangers have been the most common choice in the industry. Despite some limitations, their main advantage is that they have been extensively investigated and reliable design tools are readily available. In other words, any alternative design should not only...
To maximise power density practical gas turbine combustion systems have several injectors which can lead to complex interactions between flames. However, our knowledge about the effect of flame-flame interactions on the flame response, the essential element to predict the stability of a combustor...
A framework for unified analysis of small-signal and large-signal power system stability based on static and dynamic eigenvalues is proposed in this paper. The presented implementation is based on Gear's method, which is a two-step integration method for numerical simulation with self-adaptive time...
Randomly selected generator bars from a 50-year-old Norwegian hydro power generator were examined in this work. Typical non-destructive tests, as partial discharge and dissipation factor measurements were initially performed at both 50 Hz and 0.1 Hz. Then, the AC breakdown strength of the epoxy/mica...
This work investigates the distributed detection of carbon dioxide (CO2) release from storage tanks caused by the opening of pressure relief devices via inexpensive sensor devices in an industrial context. A realistic model of the dispersion is put forward in this paper. Both full-precision and rate...
The field data from an integrated CO2 refrigeration system installed in a supermarket located north of the capital of Lisbon was analyzed. The goal was to demonstrate the effect and performance of multi-ejectors on a refrigeration system operating in a warm climate. The measurement results for the...
In this paper, five strategies for controlling the negative sequence currents of a Virtual Synchronous Machine (VSM) under unbalanced conditions are comparatively assessed, considering both grid-connected and islanded operation. While these strategies have been individually proposed in recent...
Smart distribution grids have new protection concepts known as fault self-healing whereby Intelligent Electronic Devices (IEDs) can automatically reconfigure the power circuits to isolate faults and restore power to the relevant sections. This is typically implemented with IEDs exchanging IEC...
Energy storage technologies are required to ensure stability of energy systems when the share of renewable energy forms (wind and solar) is increasing. Liquid air energy storage (LAES) is a promising technology for storing electricity with certain advantages, such as high energy density and being...
The concept of a shared mooring system, in which adjacent wind turbines are coupled by sharing mooring lines, has been proposed to reduce the mooring costs of floating offshore wind farms. This work investigates the influence of aerodynamic loads on a floating offshore wind farm of two spar wind...
In this work, a novel ejector design concept of a swirl-bypass nozzle is proposed to improve off-design performance of CO2 two-phase ejectors. The swirl-bypass nozzle allows part of the flow to bypass into the ejector mixing chamber to generate swirl. The design of such a device is investigated...