Rig Hardware Research Articles

Metal hydride reactor for output temperature control

Precise temperature control of fuel cell stacks is crucial to avoid degradation mechanisms and thus to extend lifetime. The present study demonstrates that metal hydride based modules can assist in controlling this temperature by serving as active thermal energy storage. The reversible reaction of metals with hydrogen is characterized by a temperature pressure correlation. Therefore, the temperature as well as the thermal power at which the thermal energy is released can be defined by the gas pressure. This enables the design of temperature controllers using the pressure as actuating variable on the metal hydride device. In this study, an existing metal hydride reactor based on LaNi4.85Al0.15 is integrated into a hydrogen and cooling fluid testing infrastructure. Based on experiments indicating the step response behaviour, the parameters for a 0D model have been identified. A PI controller was designed based on simulations and implemented on the test rig hardware. First experimental results show that it is possible to stabilize the temperature of the cooling fluid circuit to 70°C ± 1.5 K while a thermal power of +755 W/kgMH and 140 W/kgMH is provided for absorption and desorption, respectively.

Drilling Automation - A Robot Takes Over the Drilling Floor

The work on the drilling floor of the PaceR801 rig revolves around a stout robot methodically picking up sections of pipe and moving them precisely over the drilling center to rapidly connect the pipe. While it is one of many technological advances on the rig Nabors bills as “the world’s first fully automated land rig,” the robot is the one “that gets most people interested and excited,” said Travis Purvis, senior vice president, global operations for Nabors Industries Ltd. As of 18 October, the PaceR801 had completed the first well on an ExxonMobil pad and was drilling the lateral on the second well of the three-well pad. After the third is done, the extended test will move to the next pad. It is risky to announce who came in first in a competitive race in a secretive business. But Nabors stands out because the PaceR801 has an automated drilling floor, a range of other automated functions above and below ground, and most significantly, it is the only one using its rig to drill producing wells for a customer. Jason Gahr, operations manager for unconventional drilling at ExxonMobil, said the research collaboration “demonstrates the ability to optimize drilling using the combined power of robotics, automation, computing, and data.” Since the announcement, Nabors has heard from other oil companies. “There is strong interest in the rig in many markets,” Purvis said. The companies’ interests range from automating more drilling functions by retrofitting rigs, to wanting to hire the rig, whose name is frequently shortened in conversations to R801. There is only one PaceR801 and it is going to be tied up for a while. “We expect to drill multiple test wells on multiple pads and continue to work on the technology” with ExxonMobil, Purvis said. It was created to show off the fruits of a 5-year drive to create a totally automated version of its Pace high- specification rig. Nabors likens it to the concept cars built by automakers to show off their vision of the future and to promote innovation within the company. In this case, it is a vision of the near future. While the automated drilling floor is new, much of the rest is recently proven technology. Two of the drilling automation programs used—Nabors’ SmartSLIDE and SmartNAV—are already on 30% of the Nabors fleet, said Austin Groover, director of operations for smart products at Nabors. Those applications, which manage drilling of the curve and directional drilling, plus a third that automates drilling a stand of pipe, SmartDRILL, have been used by ExxonMobil for 2 years. Maximizing the performance of a rig with multiple proven technologies plus a new one such as a robotic drilling floor required developing a system that coordinates the movements of those apps and the rig hardware while drilling. When Nabors experts describe that process, they rely on musical metaphors, from the robot doing its little dance to a conductor leading a symphony.

Experimental rig investigation of a direct interconnection technique for airborne wind energy systems

Airborne wind energy is a new approach to reach the stronger and more consistent winds at higher altitudes. In this paper, the interconnection of pumping mode airborne wind energy systems inside an energy farm is investigated. An experimental rig hardware setup has been designed and built to model an AWE farm in small scale. A direct interconnection system has been developed and examined on the experimental test rig. The direct interconnection technique (DIT) is a new method developed for the interconnection of marine wind energy systems within an energy farm, without requiring offshore-based power electronic converters. DIT relocates power electronic converters from the offshore site to the shore substation by interconnecting marine generators directly to a common bus. This method makes possible significant improvements to the economy and reliability of marine renewable energy systems. In this paper, for the first time, the direct interconnection technique is investigated experimentally for physically emulated pumping mode airborne wind energy systems. The construction of the experimental rig hardware setup is described, and the laboratory test results for the direct interconnection of airborne wind energy systems are presented and discussed.

NOX reduction in an axially staged gas turbine model combustor through increase in the combustor exit Mach number

Advanced combustion technologies to limit NOX production are needed to meet rigorous emissions standards, which are required due to the harmful effect of NOX on the environment. One such advanced concept involves axially staging the fuel to create a staged combustion system. This paper reports on emissions measurements obtained for premixed natural gas and air reacting jets into vitiated crossflow with negligible swirl at conditions corresponding to elevated inlet temperatures of 500–600 K and an elevated combustor pressure of 500 kPa. A significant NOX reduction was achieved when the staged combustor exit Mach number was increased and the axial residence time was reduced. Based on this preliminary investigation, a test matrix was developed to independently vary the exit Mach number for a constant axial residence time by utilizing modular rig hardware to change the length of the axial combustor. Up to 70% reduction in NOX produced by the axial stage was observed when the combustor exit Mach number was increased from about 0.26 to 0.66 at a constant residence time of 1.4 ms. NOX reduction based on variation in the Mach number and at a constant residence time has not been previously reported in the literature to the best of our knowledge. This decrease in NOX is hypothesized to be due to the lower static temperature of a compressible flow and potentially better mixing of the jet with the crossflow due to the interaction occurring at high speeds. The effects of axial residence times on NOX emissions were also investigated at a constant Mach number of 0.44 for axial residence times between 0.8 and 2.3 ms. Varying the axial residence time was observed to have a strong effect on NOX emissions for exit total temperatures greater than 1900 K, which agrees well with existing trends.

Realtime-capable FE-based railway catenary emulation via pantograph test rig impedance control

This work shows novel results of emulating railway catenary dynamics on a test rig for pantograph testing in order to provide for virtual test rides of railway pantograph current collectors under laboratory conditions. A realtime-capable finite-element model of a railway catenary is formulated efficiently in moving coordinates. An advanced test rig impedance control architecture is adopted for the finite-element model structure, and detailed simulations of an existing full-size pantograph test rig are carried out. The high fidelity of the realtime catenary model as well as the emulation performance of the closed-loop test rig setup in contact with a pantograph model provides promising results for the future implementation of the simulation/control architecture on the test rig hardware.

LabHouse: System simulation and emulation within boiler development

The LabHouse is an emulation test rig for boilers in which future operating conditions are reproduced dynamically in real time. The environment of the boiler is reproduced by a TRNSYS-simulation. The control of the test rig hardware and the interface to simulation use the software LabVIEW. The hardware interfaces include not only electrical signals, but also water temperatures and hydraulic resistances. This paper sheds light on the structure, the function and some examples for the practical application of this tool inside industrial development: early system testing (fault detection), derivation of a solid base for long-run bench tests and derivation of future requirements.

Computer control of a complex block-loading test

This paper describes the rig used for the full-scale fatigue testing of an oilfield production riser connection. The complex block-loading spectrum and the need to co-ordinate data acquisition with the loading made a real-time, computer-based control system an attractive, perhaps an essential, solution. It is seen that in the integrated system of electronics, servohydraulics and rig hardware, the computer functioned as a man/machine interface. Aspects of safety to which the computer contributed are highlighted, but the importance of electro-mechanical devices is also recognized. It was found that a multiple checking technique was a valuable tool in avoiding nuisance tripping of the safety circuit. Finally, the main advantages of the computer-based control system are summarized.