Rashladni tunel za zamrzavanje ribe

master's thesis

• Title (english): Freezing tunnel for fish
• Author: Robert Nemanić
• Mentor: Vladimir Soldo (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-05-13, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

U ovome radu projektiran je protočni rashladni tunel za zamrzavanje ribe kapaciteta 3500 kg/h. Postrojenje je kaskadne izvedbe s radnom tvari R744 (CO2) u donjoj kaskadi te s R717 (NH3) u gornjoj kaskadi. Kondenzator gornje kaskade evaporativne je izvedbe, dok je isparivač donje kaskade izveden kao potopljeni isparivač. Rashladni učinak rashladnog tunela iznosi 350 kW, dok temperatura isparavanja iznosi -45 °C. Nadalje, u radu su provedeni termodinamički proračuni potopljenog isparivača i evaporativnog kondenzatora, čime su određene potrebne dimenzije aparata. Za procjenu gubitka vode na evaporativnom kondenzatoru napravljena je analiza gubitka vode za ljetne mjesece.
Za određivanje termodinamičke valjanosti kaskadnog rashladnog procesa provedena je eksergijska analiza sustava kojom je utvrđeno da eksergijski stupanj djelovanja sustava iznosi 52,2 %. U radu je također napravljena shema spajanja i automatske regulacije sustava te dispozicijski crtež kaskadnog rashladnog sustava.

Abstract (english)

In this paper, continuous freezing tunnel for fish with a capacity of 3500 kg/h was designed. The plant is designed as cascade refrigeration system with R744 (CO2) in the low temperature cycle and R717 (NH3) in the high temperature cycle. For the heat rejection in the high temperature cycle an evaporative condenser is used, while the evaporator in the low temperature cylce is designed as flooded evaporator. The cooling capacity of the freezing tunnel is 350 kW, while the evaporation temperature is -45 °C. Furthermore, thermodynamic calculations of flooded evaporator and evaporative condenser were performed, which determined the required dimensions of the apparatus. In order to estimate the water loss on the evaporative condenser, an analysis of water loss for the summer months was made.
To determine the thermodynamic validity of the cascade refrigeration process, an exergy analysis of the system was performed, which determined that the exergy efficiency of the system is 52.2%. In this paper, process flow diagram with automatic control and the layout drawing of the cascade refrigeration system are also made.

• Keywords: rashladni tunel; zamrzavanje ribe; kaskadni rashladni sustav; prirodne radne tvari
• Keywords (english): freezing tunnel; fish freezing; cascade refrigeration system; natural refrigerants
• Language: croatian
• URN:NBN: urn:nbn:hr:235:781872
• 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: 2022-05-11 10:32:52