Simulation of Humid Gas Expansion for FC Turbochargers

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21220%2F24%3A00381753" target="_blank" >RIV/68407700:21220/24:00381753 - isvavai.cz</a>

Výsledek na webu

<a href="http://fs12120.fsid.cvut.cz/articlelib/2024/Z24-09_Expansion_of_humid_gas_v2.pdf" target="_blank" >http://fs12120.fsid.cvut.cz/articlelib/2024/Z24-09_Expansion_of_humid_gas_v2.pdf</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Simulation of Humid Gas Expansion for FC Turbochargers

Popis výsledku v původním jazyce

The report describes state change differential equations and their integration applied to expansion (or compression) of gas mixtures with high humidity level, typical for outlet of pressurized air in a PEM FC. The data needed for simulation are extracted from perfect gas measurements and from IAPWS formulas, considering very low partial pressure of steam. In the first approximation, the only real gas behavior factor is caused by phase change of steam to liquid water or backwards. The model has been amended by influence of internal losses in a turbine (irreversible adiabatic change) on temperature-pressure dependence, because it changes the conditions for phase change occurrence. The influence of density change due to condensation at exit kinetic energy loss in a turbine was considered, as well. The direct integration of governing differential equation is used for finding the spot where phase change starts during expansion. The use of averaged isentropic exponent has proven as numerically unstable, if this spot occurs inside a turbine. Higher pressures and lower air excess support the condensation upstream of a turbine. In such a case, the averaged isentropic exponent, close to one, can still be used. The equation can be used for compression of humid air or gas without changes. The aftercooling needs to respect real heat transfer additionally. Throttling can be simulated, as well. The report describes the algorithms to result 4-WP06-001 and to 4-WP06-004.

Název v anglickém jazyce

Simulation of Humid Gas Expansion for FC Turbochargers

Popis výsledku anglicky

The report describes state change differential equations and their integration applied to expansion (or compression) of gas mixtures with high humidity level, typical for outlet of pressurized air in a PEM FC. The data needed for simulation are extracted from perfect gas measurements and from IAPWS formulas, considering very low partial pressure of steam. In the first approximation, the only real gas behavior factor is caused by phase change of steam to liquid water or backwards. The model has been amended by influence of internal losses in a turbine (irreversible adiabatic change) on temperature-pressure dependence, because it changes the conditions for phase change occurrence. The influence of density change due to condensation at exit kinetic energy loss in a turbine was considered, as well. The direct integration of governing differential equation is used for finding the spot where phase change starts during expansion. The use of averaged isentropic exponent has proven as numerically unstable, if this spot occurs inside a turbine. Higher pressures and lower air excess support the condensation upstream of a turbine. In such a case, the averaged isentropic exponent, close to one, can still be used. The equation can be used for compression of humid air or gas without changes. The aftercooling needs to respect real heat transfer additionally. Throttling can be simulated, as well. The report describes the algorithms to result 4-WP06-001 and to 4-WP06-004.

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

20303 - Thermodynamics

Projekt

<a href="/cs/project/TN02000054" target="_blank" >TN02000054: Národní centrum kompetence inženýrství pozemních vozidel Josefa Božka</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

C - Předmět řešení projektu podléhá obchodnímu tajemství (§ 504 Občanského zákoníku), ale název projektu, cíle projektu a u ukončeného nebo zastaveného projektu zhodnocení výsledku řešení projektu (údaje P03, P04, P15, P19, P29, PN8) dodané do CEP, jsou upraveny tak, aby byly zveřejnitelné.