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The Netherlands has an extensive pipeline infrastructure for the transport and storage of natural gas. This existing infrastructure could be used in the future for hydrogen transport. For reasons of personal and environmental safety and to ensure reliable supply, the infrastructure is built and operated according to standards and norms for pipeline integrity. Currently, the reliability is ensured by complying with design codes and standards and by using systematic approaches for maintenance and trouble-shooting. The question arises whether the same amount of energy transported with hydrogen as currently with natural gas results in a larger impact on the integrity of the system and the environment around it. High flow velocities are associated to larger pressure drop and higher risk of noise emissions, vibrations and erosion. The flow speed is determined by the selection of system capacity, operating conditions, hardware sizing and economic evaluation. The combination that provides the lowest levelized cost of transport determines what the resulting flow velocity is at all points of the transport system. However, the flow velocity itself can be a constraint in this optimization due to the risks mentioned. For natural gas, this limit is commonly set at 20 m/s (72 km/h), though this is not the case for every segment of the network and at specific locations this can reach higher values. If the same limit would be applied to hydrogen, it may be an unnecessarily conservative constraint on the capacity of new and re-used systems to transport energy. In this study, a review is made of flow-induced risk mechanisms for intrusive equipment, flow-induced turbulence, flow-induced pulsations, acoustics-induced vibration, flow-induced noise and erosion. Capacity from a pressure drop perspective is also checked. This is done scoping the Dutch high-pressure gas transport system (GTS), through the RNB systems, up to the gas receiving spot for the end user. A generic benchmark between natural (G-) gas and hydrogen is presented, when an equal energy transport capacity between the two carriers is assumed, which in practice means whether hydrogen can flow 3 times faster than natural gas. The objective of the benchmark is to evaluate whether under this assumption, any of the phenomena analysed hinders transport at such conditions. In other words, whether the allowable flow velocity for hydrogen can be larger than the value traditionally used for natural gas., Dit project is medegefinancierd door TKI Nieuw Gas | Topsector Energie uit de PPS-toeslag onder referentienummer TKI2020-HyDelta.

The water injection system of an FPSO active in the Gulf of Guinea is to increase injection capacity to levels that are threatening from a flow-induced vibration perspective, such that hydrocarbon recovery can be accelerated. A three-tier method based on the internal guidelines of the system operator has been employed to assess the level of FIV threat expected from the increase in flow rate. A high-level screening analysis is followed by a more detailed approach, modified in this case by introducing knowledge obtained from field data gathered during a comprehensive measurement campaign aboard the FPSO. In particular, the data has been used to calibrate the finite element model of the mechanical layout of the pipework and associated supporting by making use of an optimization technique. The PSD of the flow excitation has been calibrated to match the measured response of the system, with descriptions of the turbulent excitation introduced in elbows by means of PSD functions available in the open literature. The PSDs, once calibrated, are further scaled to the future flow-rates so that they can be used as input to the mechanical response analysis. Though the high-level screening analysis delivers the conclusion that flow rates should be limited, the detailed analysis proves that the expected vibrations will be acceptable.

The energy transition will profoundly change the energy infrastructure. The target is to decarbonize applications and processes currently supplied with fossil fuels: industry, power generation, households, agriculture and mobility. This must be done as quickly as possible, attaining full decarbonization by 2050. The speed of the energy transition depends on public and industrial acceptance of the energy system infrastructure, which are mainly driven by affordability and reliability. Though sometimes perceived as competing goals, experience shows that reliable designs are also the most costeffective in the long term. To keep costs low in the short term, new, lean infrastructure needs to be developed, or re-purposing existing infrastructure must be enabled. The energy transition requires more flexibility in the energy system to accommodate the intermittent nature of renewable sources and guarantee security of supply. This is achieved by long-term energy storage enabled by novel energy carriers. Natural gas, as one of the most important fossil energy carriers in our system, will be replaced by renewable gas, such as biogas, synthetic gas and hydrogen. Key molecules such as hydrogen and carbon dioxide are to be handled at scales and operating conditions for which there is no precedent, posing unknowns and challenges to operators and engineering contractors. Luckily, neither these substances alone nor the scales alone are alien to industry. However the application range is now expanding. This is the time to make the most of the knowledge developed for over a century in the production, storage and transport of traditional fuels as well as in the chemical industry. In this paper, an inventory of points of attention with regards to reliability of energy infrastructure is offered, contributing to the affordability and reliability of the energy system of the future. A basis from which we can boost the energy transition.

To be able to predict the onset of flow induced pulsations in real risers, with variations in corrugation geometry and process conditions along the risers, a set of experiments was done with a variation of gap width and Reynolds number. In addition to configurations with constant cavity geometry also a geometry was tested in which the gap width varied. The damping, source strength and onset were determined via passive damping experiments and flow tests. The source strength was proportional to the (gap width)1.55 and with the Reynolds number according (1+M)Re0.25. The measured source strength of the varied geometry could be reconstructed from the power curves of individual cavities. That means no hydrodynamic interaction between cavities was observed in the geometries containing a mixture of different cavity geometries

Introduction: Interferon-gamma release assays are widely used for the diagnosis of tuberculosis infection in low-prevalence countries. However, there is no consensus on their application. The objective of this study was to develop guidelines for the use of interferon-gamma release assays in specific clinical scenarios in Spain. Methods: A panel of experts comprising specialists in infectious diseases, respiratory diseases, microbiology, pediatrics and preventive medicine, together with a methodologist, formulated the clinical questions and outcomes of interest. They conducted a systematic literature search, summarized the evidence and rated its quality, and prepared the recommendations following the GRADE (Grading of Recommendations of Assessment Development and Evaluations) methodology. Results: The panel prepared recommendations on the use of interferon-gamma release assays for the diagnosis of tuberculosis infection in the contact-tracing study (both adults and children), health care workers, immunosuppressed patients (patients infected with human immunodeficiency virus, patients with chronic immunomediated inflammatory diseases due to start biological therapy and patients requiring organ transplant) and for the diagnosis of active tuberculosis. Most recommendations were weak, mainly due to the lack of good quality evidence to balance the clinical benefits and disadvantages of the interferon-gamma release assays as compared with the tuberculin skin test. Conclusion: This document provides evidence-based guidance on the use of interferon-gamma release assays for the diagnosis of tuberculosis infection in patients at risk of tuberculosis or with suspicion of active disease. The guidelines will be applicable in specialist and primary care and in public health settings. © 2016 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Turbo compressors can generate tonal noise in a frequency range of 1000 to 5000 Hz, which may cause nuisance in the environment where the machine is installed. The cause of this tonal noise is the interaction between the flow and the rotating blades inside the compressor. The noise is transmitted from the compressor into the pipe system at both suction and discharge sides. Then it is radiated from the pipe walls to the environment. As this noise source can’t be avoided, if necessary a silencer can be installed between the compressor and the pipe system. The silencer blocks the transmission of the noise. The most common type of silencer for this application is the so-called absorption type. However, due to high flow velocities and vibrations, the absorption material may deteriorate and be blown away. A sturdier silencer type has been developed based on rigid acoustic resonators. In this paper the development process is described. This includes one and three dimensional acoustic modeling, scale model tests and the design for a full scale application. Compared to the absorption type silencer, the final silencer design has similar or lower pressure loss and fits in the same containment.

In the process of Carbon Capture and Storage (CCS), the compression stage is of paramount importance. Typically, the stream of CO2 is compressed from pressures of about 1.5 bar to above 100 bar, for which several stages are necessary. Isothermal compression is strived for, since it delivers the optimal efficiency. The compression follows a quasi-isothermal process, by making use of heat exchangers to cool down the stream right after it is compressed and enters the next stage. Because the stream contains a small amount of water, which can cause corrosion and thus jeopardize the integrity of the compressor itself or the transfer line downstream, dehydration also takes place at some stage during he compressor process.

Field plants can be exposed to several stresses. Early detection of any change in plant health is important in order to undertake an action to restore its vitality. In this paper, a new approach towards characterization of nutritional lacks in wheat leaves of different varieties has been proposed. The developed procedure is based on a laser-induced fluorescence (LIF) imaging system, which allows scanning of emission intensity distribution over the sample surface. Importantly, the new technique is non-invasive and allows for in-situ field analysis of leaves, as the LIF system is housed in a laboratory vehicle. Detection is based on chlorophyll fluorescence-emission band ratios. It allows for the analysis of leaf surface and for the establishment of the relation between emission and the type of wheat variety. The measurements were made in test areas grown with different varieties of a particular wheat type, called long cycle wheat. The proposed technique provides an appropriate method of analysis of different wheat varieties with regard to irregular weather conditions in the investigated region.