Experimental validation of a self-calibrating cryogenic mass flowmeter

The Karlsruhe Institute of Technology (KIT) and the WEKA AG jointly develop a commercial flowmeter for application in helium cryostats. The flowmeter functions according to a new thermal measurement principle that eliminates all systematic uncertainties and enables self-calibration during real operation. Ideally, the resulting uncertainty of the measured flow rate is only dependent on signal noises, which are typically very small with regard to the measured value. Under real operating conditions, cryoplant-dependent flow rate fluctuations induce an additional uncertainty, which follows from the sensitivity of the method. This paper presents experimental results with helium at temperatures between 30 and 70 K and flow rates in the range of 4 to 12 g/s. The experiments were carried out in a control cryostat of the 2 kW helium refrigerator of the TOSKA test facility at KIT. Inside the cryostat, the new flowmeter was installed in series with a Venturi tube that was used for reference measurements. The measurement results demonstrate the self-calibration capability during real cryoplant operation. The influences of temperature and flow rate fluctuations on the self-calibration uncertainty are discussed

Development of HTS current leads for industrial fabrication

High temperature superconductor current leads have been demonstrated to provide cryogenic savings compared to conventional copper leads. The applicability of HTS current leads to industrial fabrication is now a possibility. CRPP and WEKA AG are collaborating in the development of current leads for currents in the range of 3 kA to 30 kA, which are suitable for industrial fabrication. The design of these leads is such that the architecture and construction can be easily scaled to the required current level. The main components of these current leads are an HTS module, a copper heat exchanger, and cold and warm end connections. Two 10 kA prototype current leads, mainly distinguished by different designs of the copper heat exchanger, will be constructed. They will be tested at CRPP to verify the manufacturing processes and the overall design

Results of the Test of Industrially Manufactured HTS Current Leads With Novel Design Features

In the framework of a collaboration, CRPP (Centre de Recherches en Physique des Plasmas) and WEKA AG have developed high-temperature superconductor (HTS) current leads for currents in the range of 3 to 30 kA, which are suitable for industrial fabrication. In the development project, two 10 kA HTS current leads, mainly distinguished by the design of the copper heat exchanger and the transition zone between the HTS module and the heat exchanger, have been manufactured by WEKA AG and tested at CRPP. The test of the current leads covered their behavior under normal operating conditions as well as in the case of a loss of flow. Furthermore, a quench of the current leads was initiated by increasing of the helium temperature by means of heaters immediately before the inlet. The measured quench temperatures provide an estimate of the operational limits of the 10 kA HTS current leads

Cost Overruns in Hydrocarbon Megaprojects: A Critical Review and Implications for Research

Cost overruns are prevalent in hydrocarbon (oil and gas) megaprojects. A recent report indicates that 64% of ongoing megaprojects globally are facing cost overruns. Despite their increasing occurrence, there has been limited published research in the mainstream literature that has specifically examined why and how they occur. Consequently, suggestions regarding how to constructively address cost overruns in hydrocarbon megaprojects are scant. To better understand the causal nature of cost overruns in hydrocarbon megaprojects, this article provides a critical review of the extant literature. Findings from the research indicate that complex interactions between project characteristics, people, technology, and structure and culture contribute to cost overruns occurring. As a result, it is suggested that chaos theory can be used to explain how cost overruns arise in hydrocarbon megaprojects. This article provides a reference point for engendering future research in this pervasive and fertile area