Optimizacija cijevnih mreža za uzorkovanje zraka u sustavu detekcije dima

master's thesis

• Title (english): Optimization of pipe network in aspirating smoke detector
• Author: Tomica Višak
• Mentor: Zdravko Virag (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2017-05-19, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U ovom radu se analizira sustav za uzorkovanje zraka u svrhu detekcije dimnih plinova, odnosno požara u prostoriji ili električnim i elektroničkim ormarima, sa stajališta transportnog vremena potrebnog za putovanje uzorka zraka od usisnog otvora do analizatora. Provjerene su dosadašnje metode računanja transportnog vremena koje bi se mogle koristiti za funkcije cilja i pokazano je da te metode ne daju u svim slučajevima najbolja rješenja i da su greške u odnosu na numeričku simulaciju velike u prvom analiziranom slučaju. Isto tako je pokazano da će se dogoditi „spor“ transport ako su priključne cijevi puno manjeg promjera u odnosu na glavne vodove. Uzimajući u obzir navedeno zaključeno je da je dobro imati nešto tanje cijevi i cijevi podjednakog promjera na glavnom i priključnom vodu. U radu je prvo prikazana minimizacija transportnog vremena od najudaljenijeg mjesta uzorkovanja zraka i pokazano je da se u tom slučaju dobivaju najmanja transportna vremena, ali se dobiva velika neravnomjernost protoka. Nakon toga je provedena optimizacija specifičnog vremena transporta kako bi se postiglo približno jednako vrijeme za sve cijevi, optimiranje kako bi protoci na mjestima uzimanja uzorka bili približno jednaki, te je optimirana kombinacija prethodna dva slučaja. Najbolja rješenja je dala kombinacija optimiranja vremena i protoka.

Abstract (english)

This paper analyzes the air sampling system for the purpose of fire detection in the room or electric and electronic closets, from the point of view of the transport time required to travel the air sample from the inlet to the analyzer. Existing methods for transport time calculation that could be used for the objective functions were tested and showed that these methods do not provide the best solutions for all case and that the errors in comparison to the numerical simulation are large in first analyzed case. It has also been shown that "slow" transport will occur if the connecting pipe are much smaller in diameter than the main pipe. Taking into account the above, it has come to the conclusion that it is good to use thinner pipes and pipes of the approximately same diameter on the main and the connection pipes. In this paper first was minimize transport time from the furthest air sampling point and results was shown that in this case the minimum transport times were obtained, but large unevenness of the flow was obtained. Thereafter optimization of transport time was carried out in order to achieve approximately the same specific time for all pipes and optimizing the flow to the sampling points to be approximately same. Optimization for combination of the previous two cases provided the best solution.

• Keywords: Detekcija požara; Transportno vrijeme; Analitički model; Računalna dinamika fluida; Transport kemijskih vrsta; Optimiranje
• Keywords (english): Fire Detection; Transport Time; Analytical Model; Computational Fluid Dynamics; Transport of Chemical Species; Optimization
• Language: croatian
• URN:NBN: urn:nbn:hr:235:726646
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-27 10:12:50