Izboljšanje prenosa toplote pri vrenju s strukturiranjem površin preko elektrodepozicije

zaključna naloga Univerzitetnega študijskega programa I. stopnje Strojništvo - Razvojno raziskovalni program

Jakob Karakaš (Author), Matic Može (Mentor), Iztok Golobič (Co-mentor)

Abstract

V zaključni nalogi predstavljamo izboljšanje prenosa toplote pri procesu mehurčkastega vrenja z uporabo strukturiranih površin, ki smo jih pripravili z elektrodepozicijo. Modifikacija lastnosti vrelnih površin je eden izmed glavnih pristopov k povečevanju intenzivnosti prenosa toplote pri vrenju, elektrodepozicija pa omogoča izdelavo poroznih površinskih struktur, ki pomagajo zagotavljati dotok kapljevine na vrelno površino in s tem preprečevati njeno izsušitev. S procesom elektrodepozicije smo obdelali bakrene površine, pri čemer smo spreminjali čas obdelave in preučevali vpliv naknadne obdelave s sintranjem izboljšanja lastnosti površine pri mehurčkastem vrenju. Prenos toplote na izdelanih površinah smo ovrednotili pod pogoji mehurčkastega vrenja vode v bazenu pri atmosferskem tlaku, pri čemer smo se osredotočili na kritično gostoto toplotnega toka in koeficient toplotne prestopnosti. Ugotovili smo, da čas elektrodepozicije nima signifikantnega vpliva na parametre prenosa toplote pri vrenjem na razvitih površinah, naknadna obdelava s sintranjem pa je neugodno vplivala na odpornost površin na termomehanske obremenitve med testiranjem. Najvišja zabeležena vrednost kritične gostote toplotnega toka je na strukturiranih površinah znašala 1735 kW/m2 , na neobdelani površini pa 977 kW/m2 . V primerjavi z neobdelano referenčno površino smo tako dosegli med 6% in 80%. Prav tako smo v primerjavi z referenčno površino izboljšali tudi vrednosti koeficientov toplotne prestopnosti za skoraj 100 %.

Keywords

diplomske naloge;izboljšan prenos toplote;vrenje v bazenu;kritična gostota toplotnega toka;koeficient toplotne prestopnosti;elektrodepozicija;modifikacija vrelnih površin;

Data

Language:	Slovenian
Year of publishing:	2023
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FS - Faculty of Mechanical Engineering
Publisher:	[J. Karakaš]
UDC:	536.24:66.046.7:53.08(043.2)
COBISS:	168492803
Views:	38
Downloads:	4
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Boiling heat transfer enhancement using surface structuring with electrodeposition
Secondary abstract:	In this thesis, we present the heat transfer enhancement during nucleate boiling using structured surfaces prepared by electrodeposition. Modification of the surface properties is one of the main approaches to increase the intensity of boiling heat transfer, and electrodeposition induces porosity of the surface structure, which helps to ensure the inflow of liquid towards the boiling surface and thus prevents its dryout. We treated copper surfaces using the electrodeposition process, varying the treatment time and studying the influence of post-treatment by sintering. The heat transfer on the manufactured surfaces was evaluated under pool boiling conditions using saturated water at atmospheric pressure and focusing on the critical heat flux and heat transfer coefficients. We found that the electrodeposition time has no significant effect on the boiling heat transfer parameters on the developed surfaces, and the subsequent sintering treatment had an adverse effect on the surface resistance to thermomechanical stress during testing. The highest recorded value of the critical heat flux was 1735 kW/m2 on the structured surfaces, and 977 kW/m2 on the untreated surface. Compared to the untreated reference surface, we thus achieved an increase between 6% and 80% in the critical heat flux. We also improved the values of heat transfer coefficients by almost 100% compared to the reference surface.
Secondary keywords:	thesis;enhanced heat transfer;pool boiling;critical heat flux;heat transfer coefficient;electrodeposition;surface modification;
Type (COBISS):	Final paper
Study programme:	0
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za strojništvo
Pages:	XIV, 51 f.
ID:	19921149