Dinamička simulacija rada mehaničkog termoekspanzijskog ventila u rashladnom sustavu

undergraduate thesis

• Title (english): Dynamic simulation of operation of a mechanical thermostatic expansion valve in a refrigeration system
• Author: Bruno Brđović
• Mentor: Nenad Ferdelji (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2024-02-29, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

Rashladni sustavi koriste se za snižavanje i održavanje temperature niže od okoline. Imaju široku primjenu u prehrambenoj industriji, domaćinstvu, trgovini, transportu, klimatizaciji itd. Za kvalitetan rad rashladnih sustava potrebno je odabrati optimalne komponente i parametre rada sustava. U ovom završnom radu napravljen je dinamički model isparivača i termoekspanzijskog ventila jednostavnog rashladnog sustava pri promjenjivom opterećenju. Cilj ovog rada je analizirati nestacionarni proces koji se odvija u isparivaču gdje je promjena opterećenja isparivača ostvarena promjenom brzine strujanja zraka. Analizirana je dinamika sustava pri brzinama strujanja zraka, a koje iznose 4 m/s, 5 m/s, te 2,5 m/s. Za svaku brzinu strujanja analiziran je interval od 600 sekundi u kojem je postignuto stacionarno stanje.Također, analiziran je rad sustava pri promjeni koeficijenta prijelaza topline isparavanja.Pomoću matematičkog modela isparivača i termoekspanzijskog ventila, te numeričke metode konačnih razlika, u programskom jeziku Python analiziran je utjecaj raznih parametara na sustav.

Abstract (english)

Refrigeration systems are used to lower and maintain temperatures below the ambient level. They have wide applications in the food industry, household, commerce, transportation, air conditioning, etc. For the proper functioning of refrigeration systems, it is necessary to select optimal components and system operating parameters. In this final paper, a dynamic model of an evaporator and a thermostatic expansion valve of a simple refrigeration system with variable load was developed. The aim of this paper is to analyze the non-stationary process that occurs in the evaporator, where the change in evaporator load is achieved by changing the air flow velocity. The system dynamics were analyzed at air flow velocities of 4 m/s, 5 m/s, and 2.5 m/s. For each flow velocity, a 600-second interval was analyzed to reach a steady state. Also, the operation of the system was analyred during changesin the evaporation heat transfer coefficient. Using the mathematical model of the evaporator and thermostatic expansion valve, as well as the finite difference numerical method implemented in the Python programming language, the influence of various parameters on the system was analyzed.

• Keywords: isparivač; metoda konačnih razlika; Python
• Keywords (english): evaporator; finite difference method; Python
• Language: croatian
• URN:NBN: urn:nbn:hr:235:672686
• 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: 2024-02-27 20:36:30