Energetski učinkovita proizvodnja – interdisciplinarni, sistemski pristup kroz integralnu simulaciju

If the main concern of manufacturing companies was increasing the productivity, reliability, flexibility, and quality of the industrial process, more recently the energy efficiency of the production process and facilities has come under scrutiny. To enhance the energy-efficiency of production facilities, detailed information regarding the production processes, heat emissions from machines, operation level and occupancy analysis are necessary. In this context, the present paper describes an ongoing research effort that aims to develop a systemically integrated model of an energy efficient production facility. In this context we demonstrate the initial results of the implementation of an integrated simulation approach for a specific industrial facility. On the case study of an existing facility the different levels of energy in-and outputs were analysed; starting from machines and production systems, user behaviour and building services related requirements, to the building envelope of the facility. The collected information was further processed to develop a new building design. This layout provides the basis of an initial building performance simulation model. The generated model is part of the integrated simulation approach and used as a starting point to address the impact of different design and building operation options on the indoor climate and energy performance of the industrial facility. The goal of the integrated simulation approach is to evaluate a production facility not separately for individual mandates pertaining to production process, building envelope, and systems, but in a coupled and integrated fashion. Based on the results of thermal simulation, a first life-cycle costs model is developed, upon which the crucial points for the decision-making process in the planning of an energy-efficient industrial facility can be identified.Među glavnim interesima proizvodnih poduzeća do sada su bili povećanje produktivnosti, pouzdanosti, fleksibilnosti i kvalitete industrijskog procesa, a nedavno se pod povećalom našla i energetska učinkovitost proizvodnog procesa i pogona. U cilju poboljšanja energetske učinkovitosti proizvodnih pogona potrebne su detaljnije informacije o procesu proizvodnje, izmjeni topline u strojevima i analiza učinka i zastupljenosti pogona u radu. U tom kontekstu, ovaj rad opisuje istraživanje koje je u tijeku i teži razvoju sustavno integriranog modela energetski učinkovite proizvodnje u pogonu. U tom kontekstu prikazani su početni rezultati provedbe integriranog simulacijskog pristupa za određeni industrijski pogon. U početnoj studiji slučaja postojećeg pogona analizirane su različite razine ulaznih i izlaznih podataka o energiji; uključujući strojeve i proizvodne sustave, ponašanja korisnika, učinkovitosti kućne tehnike te ovojnice zgrade pogona. Prikupljeni podaci dodatno su obrađeni u cilju razvoja novog građevinskog projekta. Prijedlog koncepcije novog pogona pruža osnovu za prikaz početnog učinka simulacijskog modela na zgradi. Razvijeni model je dio integriranog simulacijskog pristupa te se koristi kao početna točka u simulaciji utjecaja različitih koncepata organizacije prostora i volumena zgrade, kvalitete ovojnice zgrade i kućne tehnike na energetsku učinkovitost industrijskog pogona. Cilj integriranog simulacijskog pristupa je procijeniti energetske performanse proizvodnog pogona, ali ne za pojedine zadaće koje se odnose na proces proizvodnje, ovojnicu zgrade i sustave, nego na povezani i integrirani način. Razvijen je prvi modela troška vijeka trajanja koji se temelji na toplinskim simulacijama, koji je presudan u procesu donošenja odluka u planiranju energetske učinkovitosti industrijskog pogona

Effect of tensor couplings in a relativistic Hartree approach for finite nuclei

The relativistic Hartree approach describing the bound states of both nucleons and anti-nucleons in finite nuclei has been extended to include tensor couplings for the $\omega$- and $\rho$-meson. After readjusting the parameters of the model to the properties of spherical nuclei, the effect of tensor-coupling terms rises the spin-orbit force by a factor of 2, while a large effective nucleon mass $m^{*}/M_{N} \approx 0.8$ sustains. The overall nucleon spectra of shell-model states are improved evidently. The predicted anti-nucleon spectra in the vacuum are deepened about 20 -- 30 MeV.Comment: 31 pages, 4 postscript figures include

End milling of Ti-48Al-2Cr-2Nb under high-feed conditions

Gamma titanium aluminides are fast developing materials and particularly in use for aerospace and automotive components. Due to the high cutting forces and raised cutting temperatures achieved during milling of this material, tool-wear is a crucial factor. Thus, increasing of the cutting speed leads to a significant rise of the cutting temperature. On the one hand, the implementation of innovative cooling strategies can reduce the heat flux in the cutting tool. On the other hand, analysing of the heat generation during the cutting process can lead to improved machining strategies. Previous research attempts assess microstructural and chip formation, as well as tool-wear in finish milling of this material. However, few have investigated the optimal cutting strategies in roughing and finishing of titanium aluminides. In this study, the milling operation under high feed rate should be investigated and the potential to improve chip removal rate and tool life should be determined

New method for determining single cutting edge breakage of a multi-tooth milling tool based on acceleration measurements of an instrumented tool holder

In machining applications predominantly for automated machining cells, tool life is often not used to its full extend and cutting tools are exchanged prematurely to avoid tool breakage and thus machine downtime or even damage at work piece or machine. Both effective process monitoring and adequate process control require reliable data from sensors and derived indicators that enable meaningful evaluation. Acceleration measurement by the instrumented tool holder provides signals with high quality from close to the cutting zone. Using the monitoring system, the gained data of the instrumented tool holder can be analyzed especially for the use case of unexpected tool wear, chipping of the cutting edge or breakouts at end mills. This paper describes the data analysis based on the rotational sensor and the corresponding effects on the measurement, an advanced assessment of the spectral distribution in the frequency domain and the experimental results of a test series

Application Scenarios of a Tactile Surface Roughness Measurement System for In Situ Measurement in Machine Tools

The rate of automation in European industry is increasing continuously. In production metrology, the trend is shifting from measurement laboratories towards integration of metrology into the production process. Increasing levels of automation and the current skills shortage are driving demand for autonomous production systems. In this project, a roughness measurement system was developed that is fully integrated into machine tools and enables fully automatic roughness measurement of part surfaces during the machining process. Using a skidless measurement system, it was possible to obtained measured roughness values comparable to those obtained in measuring rooms under optimal conditions. The present paper shows the development process of the prototype and provides an overview of different application scenarios for in situ measurement of machine tools. In situ roughness measurement has high potential in the future of metrology in industrial applications. Not only can surfaces be measured directly in the process, sub-processes can be triggered based on the measured values, allowing the production process to react flexibly to actual conditions. Potential improvements in metrology and significant optimizations of the entire production chain are highlighted in this paper