User defined nodal displacement of numerical mesh for analysis of screw machines in FLUENT

Growing demands to reduce energy consumption are driving researchers towards in-depth analysis of positive displacement machines. Twin screw compressors are amongst the most common types of positive displacement machines. These machines have inherently complex geometry due to intricate rotor profiles used. As the details of the internal flows are difficult to obtain experimentally, Computational Fluid Dynamics (CFD) offers a good alternative for evaluation of internal flow patterns. However, implementation of CFD is challenging due complex deforming geometries. In this paper, a customised grid generator SCORGTM developed by authors is used to generate numerical meshes for commercially available solver ANSYS FLUENT. FLUENT is an unstructured solver which offers flexibility of using both segregated and coupled solution algorithms. Segregated algorithms are generally faster which results in shorter product development time. Interface with FLUENT is implemented by performing User Defined Nodal Displacements (UDND) of grids generated by SCORG in a parallel framework. For this purpose, SCORG and UDND are coupled and extended to work with FLUENT's parallel architecture. The developed code is compiled within the solver. The oil free air screw compressor with 'N' profile rotors and 3/5 lobe combination is modelled for 8000 RPM and 6000 RPM. Finally, the predicted performance values with FLUENT are compared to previously calculated CFX predictions and experimental results. FLUENT requires shorter solution time to obtain same accuracy of CFX

Current status and future development of solvent-based carbon capture

Solvent-based carbon capture is the most commercially-ready technology for economically and sustainably reaching carbon emission reduction targets in the power sector. Globally, the technology has been deployed to deal with flue gases from large scale power plants and different carbon-intensive industries. The success of the technology is due to significant R&D activities on the process development and decades of industrial experience on acid gas removal processes from gaseous mixtures. In this paper, current status of PCC based on chemical absorption—commercial deployment and demonstration projects, analysis of different solvents and process configurations—is reviewed. Although some successes have been recorded in developing this technology, its commercialization has been generally slow as evidenced in the cancellation of high profile projects across the world. This is partly due to the huge cost burden of the technology and unpredictable government policies. Different research directions, namely new process development involving process intensification, new solvent development and a combination of both, are discussed in this paper as possible pathways for reducing the huge cost of the technology

Greenhous gas emissions reduction by motor systems-The case of compressed air systems in power generation and industry

This chapter illustrates that the motor systems account for more than 60% of the electricity consumed in industry worldwide. Appropriate use of existing technologies in motor-driven systems could save about 200 billion kWh of electricity per year in Europe alone. Electricity consumption in compressed air systems is about 80 TWh in the EU-15; worldwide consumption amounts to about 400 TWh. Highest electricity consumption for compressed air occurs in the chemical industry and the steel industry, the highest share of consumption for compressed air to total consumption of 18 % occurs in the textile and leather industry. The economic energy saving potential in compressed air systems is about one third, equivalent to about 2.3 % of the industrial electricity consumption worldwide. Barriers hindering the realization of this potential are mainly managerial or financial. To achieve the same amount of emission reductions, it would be possible to retrofit one coal-fired power stat ion with carbon capture instead of optimizing 380 compressed air plants of average size. However, economics favor energy efficiency improvements

Viele Anlagen pfeifen aus allen Löchern. Großes wirtschaftliches Einsparpotential bei Druckluftanlagen

Druckluft, ein universeller Energieträger mit vielfältigen Eigenschaften und zum verschwenden viel zu wertvoll, erhält leider in den seltensten Fällen die nötige Aufmerksamkeit