Analiza valjanosti sustava povrata energije u procesima pripreme zraka

Balen, Igor (1999) Analiza valjanosti sustava povrata energije u procesima pripreme zraka. = Efficiency Analysis of Heat Recovery Systems in Air-conditioning. Doctoral thesis , Sveučilište u Zagrebu, Fakultet strojarstva i brodogradnje, UNSPECIFIED. Mentor: Donjerković, Petar.

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Abstract (Croatian)

U radu je provedena cjelogodišnja dinamička energetska analiza valjanosti povezanog sustava kružnog toka, kao rekuperativnog sustava povrata toplinske energije iz istrošenog zraka u ovisnosti o promjeni pogonskih uvjeta, odnosno promjeni stanja vanjskog okoliša. U to svrhu razvijen je originalni simulacijski model rada složenog termotehničkog sustava klimatizacije, koji uključuje povezani sustav kružnog toka i povezuje ga s dizalicom topline. Razvijeni simulacijski model omogućuje cjelogodišnju satnu analizu rada sustava, uz pracenje utroška i povrata topline i tvari toplinskih aparata, utroska električne energije uredaja na električni pogon, to određivanje satnih vrijednosti stupnja iskorištenja sustava povrata topline. Model je primjenjiv na prostoriju proizvoljnih dimenzija i orjentacije, čije se toplinsko opterecenje određuje rješavanjem sustava nestacionarnih diferencijalnih jednadžbi provođenja topline kroz elemente građevinske konstrukcije. Eksperimentalni dio rada odnosi se na određivanje toplinskog, odnosno rashladnog učinka povezanog sustava kružnog toka za različite pogonske uvjete. U to svrhu projektirana je i izvedena mjerna linija za provođenje mjerenja na povezanom sustavu kružnog toka, ugrađenom u klima komoru u stvarnoj veličini. \Na temelju mjernih rezultata određeni su stupnjevi iskorištenja sustava i provedena analiza valjanosti sustava za izmjereni niz radnih točaka. Simulacijski model za cjelogodišnju satnu energetsku analizu rada složenog sustava klimatizacije dao je konzistentne i stabilne rezultate, a pouzdanost mu je dokazana usporedbom s rezultatima mjerenja. Rezultati su pokazali da zajednička ugradnja povezanog sustava kružnog toka i dizalice topline u klima komoru ne donosi značajnu uštedu energije u odnosu na klima komoru koja ima samo dizalicu topline, međutim, time se omogućuje ugradnja dizalice topline s kompresorom manje električne snage. S druge strane, ušteda energije u usporedbi s klasičnom klima komorom pokazala se vrlo povoljnom, što ukazuje na važnost gospodarenja energijom u procesima pripreme zraka tijekom godine. Optimiranje rada slozenih sustava klimatizacije, pored financijskih pogodnosti, daje doprinos i zaštiti čovjekova okoliša. Dobiveni rezultati za sekundarne toplinske aparate pripremljeni su za daljnju sveobuhvatnu energetsku i gospodarsku analizu rada sustava klimatizacije, koja bi uključivala investicijske troškove, troškove energije i troškove održavanja. Razvijeni simulacijski model vrlo je fleksibilan i može uključiti različite sustave povrata toplinske energije ili druge termotehničke sustave radi njihove analize i međusobne usporedbe

Abstract

In this paper, dynamic energy analysis of the coil energy recovery loop's efficiency during the whole year, in dependence of the operating conditions, i.e. outside air thermodynamical state, was performed. A coil energy recovery loop is one of the air-to-air sensible heat recovery systems with finned tube water coils, placed in the supply and exhaust air streams and connected in a closed loop via counterflow piping. For this purpose, the original simulation model of a complex air-conditioning system, which includes both the coil energy recovery loop and the heat pump, was developed. The developed simulation model enables hourly analysis of the system operation during the whole year, together with monitoring of both consumption and recovery of heat and mass for the system parts, electricity consumption of the electrical appliances, and also with determination of hourly efficiency values for the air-to-air heat recovery system. The model is applicable to a room of any dimensions or orientation, where a heating, i.e. cooling load is determined by solving the unsteady heat conduction equation system through the building's construction elements. The measurements were performed to determine heating, i.e. cooling capacity of the coil energy recovery loop in different operating conditions. For this purpose, the experimental rig was designed and installed in order to conduct the measurements on the coil energy recovery loop, placed in the air-conditioning unit in its real dimensions. Based on the measurement results, the system efficiency analysis for the measured operating points set was performed. With the simulation model for dynamic energy analysis of a complex air-conditioning system during the whole year, consistent and stabile results were obtained, and their reliability was proven by comparison with the measurement results. The results have shown that together building of both the coil energy recovery loop and the heat pump into the air-conditioning unit, does not increase the energy saving significantly in comparison to the air-conditioning unit with the heat pump only. On the other hand, in former case is possible to apply the heat pump with smaller electrical power. The energy saving in comparison with the standard air-conditioning unit has been proven to be very significant, which points out the importance of energy management in the air-conditioning processes during the year. The optimization of the complex air-conditioning units operation has many, not only financial, but also environmental protection advantages. The obtained results for the secondary parts of the air-conditioning systems were prepared for further complete both the energy and the economy analysis, which should include the investment costs, the energy and fuel costs and the maintenance costs. The developed simulation model is flexible and has the possibility to include different types of air-to-air heat recovery systems or other air-conditioning systems in order to perform. their analysis and/or their mutual comparison.

Item Type: Thesis (Doctoral thesis)
Uncontrolled Keywords: dinamička energetska analiza; dizalica topline; grijanje; ventilacija i klimatizacija; simulacijski model; sustav povrata toplinske energije; utrošak energije
Keywords (Croatian): dynamic energy analysis; heat pump; HVAC; simulation model; heat recovery system; energy consumption
Divisions: 300 Department of Thermodynamics, Thermal and Process Engineering
300 Department of Thermodynamics, Thermal and Process Engineering > 320 Chair of Thermal and Process Engineering
Date Deposited: 22 Sep 2014 18:00
Last Modified: 16 Oct 2015 13:19
URI: http://repozitorij.fsb.hr/id/eprint/29

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