Current Technologies and Prospects of Shale Gas Development in China

Shale gas in China has realized the great-leap-forward development because of the significant strides of development technique for marine shale resource, becoming the second largest shale gas producer only to the USA. Benefits from the progress of technique advance, a complete technique series for the development of shale resource buried less than 3500 m has been established by operating technique research and field trail, including five main key techniques of geological evaluation, optimum and fast drilling, multistage hydraulic fracturing, productivity evaluation, and development parameters optimization. At present, shale resource in China has not been fully exploited besides the marine shale resource (3500 m). With the further process of development technique for marine shale, shale gas is expected to the single type of gas reservoir contributing to the highest annual production rate in the near future. Therefore, based on the success in shale industry, this work is organized by reviewing the advances and challenges of current evaluation techniques, and then discussing the possible development trend of shale gas performance evaluation in the future

APPLICATION OF THE WELDING PROCESS IN THE MANUFACTURE OF BOILER COMPONENTS

U diplomskom radu ukratko je opisano područje zavarivanja. U prvom poglavlju diplomskog rada navedena je podjela i opis postupaka zavarivanja pritiskom i taljenjem koji se primjenjuju u izradi komponenata kotlovskih postrojenja. U drugom poglavlju navedeni su praktični primjeri primjene pojedinih postupaka zavarivanja u pogonskim uvjetima u izradi komponenata kotlovskih postrojenja. Navedeni su detalji zavara, učinkovitost, parametri zavarivanja i ograničena u praktičnoj primjeni s obzirom na vrstu i debljinu materijala. U trećem poglavlju prikazana je automatizacija i robotizacija pojedinih postupaka zavarivanja koji se primjenjuju u kotlovskom postrojenju, opisani su primjeri iz prakse koji se obavljaju unutar proizvodnje tvrtke „Đuro Đaković Termoenergetska postrojenja d.o.o.“.This graduate thesis briefly describes welding domain. The first chapter of the thesis deals with the division and description of welding and melt welding procedures that are applied in the manufacturing of boiler plants components. The second chapter consists of practical examples of the application of certain welding procedures in operating conditions in the design of boiler plants components. Also, the details of welding, efficiency, welding parameters and limitations in practical application with respect to the type and thickness of the material are mentioned. The third chapter presents the automation and robotization of individual welding procedures applied in the boiler plant. Examples of practices that are carried out within the company „Đuro Đakoović Termoenergetska postrojenja d.o.o“ are described

Joining 3YSZ Electrolyte to AISI 441 Interconnect Using the Ag Particle Interlayer: Enhanced Mechanical and Aging Properties

Reactive air brazing has been widely used in fabricating solid oxide fuel/electrolysis cell (SOFC/SOEC) stacks. However, the conventional Ag–CuO braze can lead to (I) over oxidation at the steel interconnect interface caused by its adverse reactions with the CuO and (II) many voids caused by the hydrogen-induced decomposition of CuO. The present work demonstrates that the Ag particle interlayer can be used to join yttria-stabilized zirconia (YSZ) electrolytes to AISI 441 interconnect in air instead of Ag–CuO braze. Reliable joining between YSZ and AISI 441 can be realized at 920 °C. A dense and thin oxide layer (~2 μm) is formed at the AISI 441 interface. Additionally, an interatomic joining at the YSZ/Ag interface was observed by TEM. Obtained joints displayed a shear strength of ~86.1 MPa, 161% higher than that of the joints brazed by Ag–CuO braze (~33 MPa). After aging in reducing and oxidizing atmospheres (800 °C/300 h), joints remained tight and dense, indicating a better aging performance. This technique eliminates the CuO-induced issues, which may extend lifetimes for SOFC/SOEC stacks and other ceramic/metal joining applications

Joining 3YSZ Electrolyte to AISI 441 Interconnect Using the Ag Particle Interlayer: Enhanced Mechanical and Aging Properties

Reactive air brazing has been widely used in fabricating solid oxide fuel/electrolysis cell (SOFC/SOEC) stacks. However, the conventional Ag–CuO braze can lead to (I) over oxidation at the steel interconnect interface caused by its adverse reactions with the CuO and (II) many voids caused by the hydrogen-induced decomposition of CuO. The present work demonstrates that the Ag particle interlayer can be used to join yttria-stabilized zirconia (YSZ) electrolytes to AISI 441 interconnect in air instead of Ag–CuO braze. Reliable joining between YSZ and AISI 441 can be realized at 920 °C. A dense and thin oxide layer (~2 μm) is formed at the AISI 441 interface. Additionally, an interatomic joining at the YSZ/Ag interface was observed by TEM. Obtained joints displayed a shear strength of ~86.1 MPa, 161% higher than that of the joints brazed by Ag–CuO braze (~33 MPa). After aging in reducing and oxidizing atmospheres (800 °C/300 h), joints remained tight and dense, indicating a better aging performance. This technique eliminates the CuO-induced issues, which may extend lifetimes for SOFC/SOEC stacks and other ceramic/metal joining applications

NP-P220012B On-chip Electrocatalytic Microdevices

This protocol describes the experimental design, system construction, and data analysis of an emerging electrocatalytic platform: on-chip electrocatalytic microdevices. The source data are presented here for public access. </p

Joining Alumina and Sapphire by Growing Aluminium Borate Whiskers In-Situ, and the Whiskers’ Orientation Relationship with the Sapphire Substrate

Bonding between polycrystal alumina and sapphire with (0001), (10 1 &macr; 0), (11 2 &macr; 0), (1 1 &macr; 02) orientations is successfully achieved by growing aluminium borate whiskers in the joint. The morphology of the whiskers in the joint is characterised by (Scanning Electron Microscopy) SEM. The relationship between the growing direction of the aluminium borate whiskers and the orientation of the sapphire substrate is investigated. The effect of the growing direction of the aluminium borate whiskers on the mechanical properties of the joint is discussed. The results show that the whiskers on the sapphire with (10 1 &macr; 0) orientation grow perpendicular to the surface of the substrate while the whiskers show a random growth on the other substrates. It is found that there is an orientation relationship between the whiskers (220) and sapphire (10 1 &macr; 0) and the morphology of the whiskers has great influence on the mechanical properties of the joint. The joint between polycrystal alumina and sapphire with (10 1 &macr; 0) orientation exhibits the highest strength, which reaches 26 MPa

Exploring the role of Ag foam interlayer in alleviating the brittleness of G018 glass sealant for joining YSZ to Mn–Co spinel coated Crofer 22 H

Glass/Glass-ceramic sealing is always accompanied by issues of high porosity and brittle joints. To migrate these problems, an Ag foam was innovatively induced as an interlayer in the process of glass sealing the yttria-stabilized zirconia (YSZ) ceramic to Mn–Co spinel-coated Crofer 22 H stainless steel. Interlayer-added joints showed a significant reduction in porosity, and the shear strength was improved to 52.3 MPa, with an enhancement of 37.8 %. The influence of interlayer on the microstructure of the joint has been investigated and the formation process of the joint is illustrated. The Ag interlayer expels gases from the sealant material through expansion at high temperatures and promotes finer nucleation grains of crystallites integrating with the interlayer, reducing the porosity and alleviating the brittleness as well