Zamjena radne tvari HCFC-22 s propanom R-290 u split rashladnom uređaju

undergraduate thesis

• Title (english): Retrofitting of R-22 split air-conditioner with natural refrigerant propane (R-290)
• Author: Matej Krajinović
• Mentor: Marino Grozdek (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2016-03-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Prirodne radne tvari su među prvim radnim tvarima koje su se koristile za mehaničke sustave hlađenja. Kada su razvijene CFC i HCFC radne tvari upotreba prirodnih radnih tvari se smanjila. Zbog oštećivanja ozonskog sloja i visokog GWP-a CFC i HCFC radne tvari su izbačene. Iz istog razloga sustavi koji su koristili HCFC radne tvari zamjenjuju se prirodnim radnim tvarima, prvenstveno ugljikovodicima (HC), taj postupak se zove konverzija sustava i ona je trenutno u porastu u svijetu. Split rashladni uređaji su u uporabi diljem svijeta i uglavnom se u njima nalazi radna tvar R-22. Zamjenska radna tvar bi trebala imati što sličnija svojstva radnoj tvari koja se zamjenjuje uz što manje preinake postojećeg sustava. Idealna zamjenska tvar za R-22 je propan (R-290) jer ima odlična tremofizikalna svojstva, bolju energetsku učinkovitost i potrebne su male preinake u sustavu. Problem s propanom i općenito sa ugljikovodicima je taj što su vrlo zapaljivi i eksplozivi. Prema tome pri provedbi procesa konverzije jako je bitno posvetiti se ispunjavanju sigurnosnih uvjeta i normi. Kada su ispunjeni zakonom propisani uvjeti za sigurnost, propan je idealna zamjenska radna tvar. U prvom dijelu rada su prikazana termofizikalna svojstava propana u odnosu na R-22, kasnije su prikazani koji su to sigurnosni uvjeti i norme koje moraju biti ispunjene. Na kraju se nalazi termodinamički proračun sustava s propanom i R-22 i njihova usporedba. Na crtežima su prikazane sheme rashladnog sustava s propanom i R-22, te potrebne konstrukcijske izmjene.

Abstract (english)

Natural refrigerants are among the first refrigerants to beused for mechanical cooling systems. After development of CFC and HCFC refrigerants, use of natural refrigerants reduced. Because of the damage to the ozone layer and the high GWP of CFC and HCFC, refrigerants were phased out. For the same reason, systems which used HCFC refrigerants were replaced with natural refrigerants, mainly hydrocarbons (HC). This procedure is called system conversion and it is increasing throughout the world. Split cooling systems are in use around the world and usually contain the refrigerant R-22. Replaced refrigerants should have similar properties to refrigerants being replaced with minimum modifications of the existing system. The ideal alternative substance for the R-22 is propane (R-290), because it has excellent termophysic properties, is more energy efficient and requires small modifications in the system. The problem with propane and generally with hydrocarbons is that they are highly flammable and explosive. In the implementation of the conversion process,it is very important to follow the safety conditions and standards. When statutory requirements for safety are met, propane is an ideal replacement refrigerant. The first part of this work presents the thermophysical properties of propane compared to R-22. The second part presents which safety conditions and standards should be met. The end contains termodynamic calculations and the comparison between systems with propane and R-22. The drawings at the end show the scheme of the cooling system with propane and R-22, including the necessary structural changes.

• Keywords: propan; konverzija
• Language: croatian
• URN:NBN: urn:nbn:hr:235:661175
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 16:07:04