The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
Erich Hahne - One of the best experts on this subject based on the ideXlab platform.
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High Temperature water pit storage projects for the seasonal storage of solar energy
Solar Energy, 1997Co-Authors: Régis Kubler, N. Fisch, Erich HahneAbstract:Central solar heating plants with seasonal storage (CSHPSS) are capable of covering more than 75% of the annual heat demand of housing areas if appropriate storage technologies are available. The Maximum Design Temperature should be 90-95°C and the long term cost goal is 100 DM m-3for a storage volume larger than 10 000 m3water equivalent. Three pilot projects are presently under construction and planning in Germany with 600, 4500 and 12 000 m3volume. The storage medium in all three cases is water. A first pilot heat storage with about 600 m3volume is being built in Rottweil. This small scale project will be applied as short term storage in connection with a combined heat and power (CHP) plant. The storage container is made of concrete, water tightness is achieved by a stainless steel liner and mineral wool is used as insulation. The aim of this project is to demonstrate the feasibility of the technology and to gain practical experience for the construction of larger stores. During 1995/96 two full scale central solar heating plants with seasonal storage (CSHPSS) of this type will be built in Hamburg, North Germany and Friedrichshafen, South Germany, with 4500 and 12 000 m3storage volume, respectively.
Régis Kubler - One of the best experts on this subject based on the ideXlab platform.
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High Temperature water pit storage projects for the seasonal storage of solar energy
Solar Energy, 1997Co-Authors: Régis Kubler, N. Fisch, Erich HahneAbstract:Central solar heating plants with seasonal storage (CSHPSS) are capable of covering more than 75% of the annual heat demand of housing areas if appropriate storage technologies are available. The Maximum Design Temperature should be 90-95°C and the long term cost goal is 100 DM m-3for a storage volume larger than 10 000 m3water equivalent. Three pilot projects are presently under construction and planning in Germany with 600, 4500 and 12 000 m3volume. The storage medium in all three cases is water. A first pilot heat storage with about 600 m3volume is being built in Rottweil. This small scale project will be applied as short term storage in connection with a combined heat and power (CHP) plant. The storage container is made of concrete, water tightness is achieved by a stainless steel liner and mineral wool is used as insulation. The aim of this project is to demonstrate the feasibility of the technology and to gain practical experience for the construction of larger stores. During 1995/96 two full scale central solar heating plants with seasonal storage (CSHPSS) of this type will be built in Hamburg, North Germany and Friedrichshafen, South Germany, with 4500 and 12 000 m3storage volume, respectively.
N. Fisch - One of the best experts on this subject based on the ideXlab platform.
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High Temperature water pit storage projects for the seasonal storage of solar energy
Solar Energy, 1997Co-Authors: Régis Kubler, N. Fisch, Erich HahneAbstract:Central solar heating plants with seasonal storage (CSHPSS) are capable of covering more than 75% of the annual heat demand of housing areas if appropriate storage technologies are available. The Maximum Design Temperature should be 90-95°C and the long term cost goal is 100 DM m-3for a storage volume larger than 10 000 m3water equivalent. Three pilot projects are presently under construction and planning in Germany with 600, 4500 and 12 000 m3volume. The storage medium in all three cases is water. A first pilot heat storage with about 600 m3volume is being built in Rottweil. This small scale project will be applied as short term storage in connection with a combined heat and power (CHP) plant. The storage container is made of concrete, water tightness is achieved by a stainless steel liner and mineral wool is used as insulation. The aim of this project is to demonstrate the feasibility of the technology and to gain practical experience for the construction of larger stores. During 1995/96 two full scale central solar heating plants with seasonal storage (CSHPSS) of this type will be built in Hamburg, North Germany and Friedrichshafen, South Germany, with 4500 and 12 000 m3storage volume, respectively.
Luis Eduardo Juanico - One of the best experts on this subject based on the ideXlab platform.
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Modified vacuum tubes for overheating limitation of solar collectors: A dynamical modeling approach
Solar Energy, 2018Co-Authors: Luis Eduardo JuanicoAbstract:Abstract In this paper are presented two Designs of vacuum tubes Designed to avoid the overheating of solar collectors. As we discuss, this behavior must be studied by considering the collector’s nonlinear dynamic, which is numerically studied by developing a solar-thermal modeling based on a fourth-order approximation for the efficiency function. In this way, the two main heat-losses mechanisms involved can be simulated and so, two kinds of modified vacuum tubes are studied: (a) by increasing its heat convection coefficient and (b) by increasing its infrared emissivity. Therefore, we have calculated their modified efficiencies in order to get a non-overheating collector, in which the Maximum Design Temperature is always kept below 111 °C (for water-in-glass tubes) or 131 °C (for heat-pipe tubes). Then, we have studied the performance of these collectors when they work on low Temperatures, showing that the first Design of modified vacuum tubes (increasing the convection heat losses) penalizes the collector’s performance up to 26%, meanwhile the second Design (increasing the infrared heat losses) does not change the collector’s performance. Therefore, a new collector based on these tubes could improve its performance on cloudy days by using a greater number of vacuum tubes. In this way, we found that by using 50 standard tubes (instead of 20 tubes) a solar collector based on a 200-l water tank could satisfy the daily household demand of hot water (200 kg@45 °C) even during cloudy days.
Matthew Walters - One of the best experts on this subject based on the ideXlab platform.
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Sulphide stress cracking test development for a weldable 13%CR supermartensitic stainless steel in simulated seabed environments
2016Co-Authors: Matthew WaltersAbstract:Weldable 13%Cr supermartensitic stainless steels are commonly used for subsea pipelines in the oil and gas industry. Although classified as corrosion resistant alloys, these steels can be susceptible to Sulphide Stress Cracking (SSC) when exposed to wet environments containing chlorides, carbon dioxide and low levels of hydrogen sulphide. Standard guidelines stipulate that laboratory SSC tests are performed at 24 °C and at the Maximum Design Temperature, however some studies suggest that the risk of SSC could be greater at Temperatures below 24 °C. Seabed Temperatures can be as low as 5 °C, so in-service cracking could occur following shut-down conditions even if the material has been qualified at 24 °C. Four-point bend SSC tests performed at 5 °C and 24 °C in simulated seabed environments showed the material was more susceptible to SSC at 5 °C, but only when the as-received pipe surface was compromised. A supporting stress and strain investigation highlighted strain concentrations on the test surface which were coincident with the location of cracking observed in the SSC tests. Finite element simulations were used to demonstrate that tensile stress-strain data should be used over flexural bend data to load four-point bend specimens to the desired loading strain.
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Hydrogen Enhanced Cracking (SSC, HIC, CF) of Tubulars and Pipelines for Sour Service in Deepwater and Seabed Applications
All Days, 2013Co-Authors: Matthew Walters, Phil Dent, Richard Doyle, Chris Fowler, Brian J. Connolly, Dean HorspoolAbstract:Abstract New technologies and associated materials advancements are required for installation of platforms, umbilicals, risers, and subsea pipelines in severe, deepwater environments. Two on-going research programmes that investigate hydrogen enhanced cracking susceptibility of material for these applications are presented. In the first part of the paper the development and application of a high Temperature high pressure corrosion fatigue facility to investigate the susceptibility of flexible pipeline components in sour environments is described. Structural integrity of the load supporting armour wires within the flexible pipe remains a concern. Such armour wires are susceptible to hydrogen embrittlement in the presence of H2S, which significantly reduces fatigue life. To simulate complex environmental conditions inherent to such challenging production locations, servo-hydraulic machines capable of testing to 50bara and 100ºC in simulated oilfield environments have been developed and installed into a state-of-the-art facility. This facility has enabled investigation of fatigue-life properties over a wide range of service environments and the data generated has contributed towards the technological advancement of flexible pipelines and risers. The second programme described presents an investigation of the effect of seabed Temperature on the sulphide stress cracking (SSC) resistance of weldable martensitic stainless steels (WMSS). WMSS are used for mildly sour flow-lines as an alternative to inhibited carbon steel or lined pipe. For most selection and qualification programmes for sour applications the material is tested in accordance with NACE MR0175 at Maximum Design Temperature and at ambient Temperature. However WMSS may be more susceptible to SSC below ambient Temperature and current information in the literature is limited. Consequently qualification to the NACE standard may show acceptable results, whereas in-service cracking could still occur. It should be noted that for sub-sea pipelines the typical seabed Temperature is in the region of 4°C, which may be experienced during ‘shut-in’ conditions. SSC testing has been undertaken on parent WMSS line-pipe at ambient and seabed Temperatures in simulated condensed and produced water at two partial pressures of H2S. Test results are presented and the SSC performance of the material is discussed with consideration to test Temperature, pH, H2S partial pressure and specimen surface condition. Introduction (PartA) Increasing demands for fossil fuels throughout the developed and developing world has promoted the Oil and Gas industry to implement recovery strategies to oil reserves once thought to be economically unviable. These ‘new’ reserves are typically located offshore in deepwater (400–1500m) and ultra-deepwater (>1500m) fields. New technologies and associated materials advancements are required for installation of platforms, umbilicals, risers, flowlines and subsea pipelines in these severe, deepwater offshore environments. According to the International Energy Agency estimates of known reserves located in such waters range from 160bn to 300bn barrels. Most of these reserves are in the waters of Brazil, Angola, Nigeria and the US and progress towards extracting these reserves has been surprisingly rapid. Ultra-deepwater production only began in 2004 and has reached 200,000 barrels per day in 2012. This number is only set to continue with huge investment in offshore facilities such as the $500m Dalian Pioneer, the biggest offshore rig yet, currently under construction in China's Liaoning Province which is capable of safely operating in waters up to 3048m deep. The development of flexible pipelines and risers has played a major role in enabling such rapid progression. Installation of these dynamic production components has been essential in allowing the Oil and Gas industry to develop fields in deeper and deeper waters, utilising floating production technologies (Figure 1).