Energy and the Environment (2016)

Transcription

1 Energy and the Environment (2016) Abstract: The paper presents a thermodynamic property analysis of four essential operating substances in diesel engine cylinder process: air, liquid fuel, fuel vapour and combustion products. Only the most important thermodynamic properties of each operating substance were taken into consideration. It was observed that the most of the thermodynamic properties are highly dependent on the operating substance temperature. Due to lack of equations for the calculation of some operating substances properties, separate approximation polynomials were presented. Polynomial coefficients were calculated by using the individually developed numerical program. Changing of thermodynamic properties for all operating substances was compared with measurements from the available literature, and developed polynomial errors were displayed. For each thermodynamic property a separate sub-program was developed, and it is possible to use these sub-programs directly in diesel engine numerical simulations. The accuracy of the diesel engine numerical simulation primarily depends on the exact calculation of the operating media thermodynamic properties, what ensures high applicability of the conducted analysis.

2 370 V. Mrzljak, T. Seni, I. Poljak: Thermodynamic property

3 Energy and the Environment (2016) T Pr

4 372 V. Mrzljak, T. Seni, I. Poljak: Thermodynamic property

5 Energy and the Environment (2016) K

6 374 V. Mrzljak, T. Seni, I. Poljak: Thermodynamic property p

7 Energy and the Environment (2016) Q A

8 376 V. Mrzljak, T. Seni, I. Poljak: Thermodynamic property A A p

9 Energy and the Environment (2016)

10 378 V. Mrzljak, T. Seni, I. Poljak: Thermodynamic property k D

11 Energy and the Environment (2016) A b c c D E k M p Pr Q R r S T

12 380 V. Mrzljak, T. Seni, I. Poljak: Thermodynamic property Mehanika fluida Heat Transfer Basic Heat Transfer Internal Combustion Engine Fundamentals Approximation for the thermodynamic and transport properties of hightemperature air Termodinamika i termotehnika Meunarodni sustav jedinica i tablice Mollier I,S-Diagramme für Verbrennungsgase in Datenverarbeitung Properties of aircraft fuels Kraftstoffaufbereitung und Verbrennung bei Dieselmotoren Viscosity of diesel engine fuel oil under pressure Sažetak: Rad prikazuje analizu termodinamikih svojstava etiri esencijalne radne tvari u procesu unutar cilindra dizelskog motora: zraka, tekueg goriva, pare goriva i produkata izgaranja. U razmatranje su uzeta samo najbitnija termodinamika svojstva svake navedene radne tvari. Tijekom provedene analize uoeno je da veina termodinamikih svojstava promatranih radnih tvari izrazito ovisi o temperaturi svake pojedine radne tvari. Zbog nedostatka tonih jednadbi za izraun nekih bitnih svojstava radnih tvari, predstavljeni su polinomi koji aproksimiraju navedena svojstava. Koeficijenti dobivenih polinoma raunati su koritenjem individualno razvijenog numerikog programa. Kretanje termodinamikih svojstava svih razmatranih radnih tvari usporeeno je sa mjerenjima iz dostupne literature, te su prikazane pogreke dobivenih aproksimacijskih polinoma. Za svako termodinamiko svojstvo svake promatrane radne tvari izraen je zaseban numeriki podprogram, te je mogua direktna primjena razvijenih podprograma u numerikim simulacijama dizelskih motora. Tonost numerike simulacije dizelskog motora primarno ovisi o preciznom izraunu termodinamikih svojstava radnih tvari, to omoguuje visoku primjenjivost provedene analize.