Expressing the Building Energy Systems Thermodynamic Seasonal Efficiency

Abstract

In order to reduce impact to environment, a qualitative approach of energy saving is global aspect that is included in various forms of CO2 emissions, primary energy limitations and benchmarks in EU and member countries policy. Exergy analysis allows expressing the quality of energy flows in comparison to ambient or other reference conditions. Despite of this valuable information, this concept is not widely used in engineering practice. The article suggests the calculation procedure for sessional or periodical thermodynamic (exergy) efficiency in relation to variable reference conditions. Knowledge about defined procedures unlocks the possibility to fill up the implementation gap for building system engineering practice where seasonal performance parameters are widely used to express efficiency. Prepared algorithm allows determining seasonal or periodic thermodynamic efficiency of individual elements and energy transfer chains in building energy systems. Defined calculation procedure workflow is suitable for integrated approach when coupled heat transfer and fluid flow processes are explored in short time steps with dynamic simulation software tools. Presented algorithm ensures result that fits in thermodynamically correct range 0-1 and helps to summarize separate time step results. By adding duration of specific conditions, this analysis enables to identify critical peak periods and base load conditions across operation period. The presented framework fills the gap in lack of systematic expression for seasonal thermodynamic efficiency and suggests the process for calculation procedures workflow.

Vėjo energiją naudojančio turbininio ventiliatoriaus termodinaminis modelis

“…Disertacijos tema paskelbti 8 straipsniai: du -Clarivate Analytics Web of Science duomenų bazėse referuojamuose leidiniuose, turinčiuose citavimo rodiklį (Rimdžius et al, 2021;Martinaitis et al, 2020); keturi -tarptautinių konferencijų leidiniuose, referuojamuose Clarivate Analytics duomenų bazėje Proceedings Streckienė et al, 2021;Streckienė et al, 2018;Januševičius et al, 2017), vienas -kitų tarptautinių duomenų bazių leidiniuose , vienaskonferencijų pranešimų medžiagoje (Sketerskis, Rimdžius, & Martinaitis, 2018). Europos patentų biure įregistruotas patentas .…”

“…A total of 8 articles have been published on the subject of this dissertation: two of them in publications peer-reviewed in the Clarivate Analytics Web of Science databases with a citation index (Rimdžius et al, 2021;Martinaitis et al, 2020); four, in conference publications peer-reviewed in the Clarivate Analytics Proceedings database Streckienė et al, 2021;Streckienė et al, 2018;Januševičius et al, 2017); one, in publications of other international databases ; one, in conference report materials (Sketerskis, Rimdžius, & Martinaitis, 2018). One patent has been registered with the European Patent Bureau .…”

Application of Energy and Exergy Analysis to Investigate the Operation of an Air Handling Unit With Heat Pump

“…Taip pat pastebėta, kad, esant tam tikrai aplinkos temperatūrai, energijos ir eksergijos suvartojama daugiausia, jei, pavyzdžiui vėdinimo sistema veikia pasirinktą sezoną (Misevičiūtė et al, 2016). Deja, vis dar nėra vienareikšmiškai sutariama dėl aplinkos atskaitos parametrų pasirinkimo ekserginėje analizėje bei sezoninių rodiklių skaičiavimo (Januševičius et al, 2017). Todėl šiuo straipsniu siekiama pavaizduoti ekserginės analizės kartu su energine analize taikymą oro paruošimo įrenginio (OPĮ) veikimui tirti, esant kintamai aplinkos temperatūrai šaltuoju sezonu (nuo -30 °C iki 10 °C).…”

Experimental Investigation of Frost Formation Influence on an Air Source Heat Pump Evaporator

“…Understanding the frost formation and its impact on the ASHP performance should be used in the software when planning an energy-efficient system. Studies show that there is a need to integrate the frosting impact [26] and defrosting techniques into software [27,28]. This is especially true with very high values (>80%) of relative air humidity [29]; e.g., in cold and humid climate conditions, the deviation between models, with frost formation excluded and factored in, is~16% [30].…”