@article{MTMT:37069462,
	title = {Értékelőmátrix kidolgozása kistelepülési távhőrendszer megvalósíthatóságának vizsgálatázhoz},
	url = {https://m2.mtmt.hu/api/publication/37069462},
	author = {Dózsa, Levente and Groniewsky, Axel},
	journal-iso = {ENGA},
	journal = {ENERGIAGAZDÁLKODÁS},
	volume = {67},
	unique-id = {37069462},
	issn = {0021-0757},
	year = {2026},
	pages = {23-25}
}

@article{MTMT:36372316,
	title = {Estimation of internal energy, enthalpy, and entropy, based on group contribution method and cubic equation of states},
	url = {https://m2.mtmt.hu/api/publication/36372316},
	author = {Groniewsky, Axel and Illés, Dávid and Hégely, László},
	doi = {10.1016/j.matchemphys.2025.131605},
	journal-iso = {MATER CHEM PHYS},
	journal = {MATERIALS CHEMISTRY AND PHYSICS},
	volume = {348},
	unique-id = {36372316},
	issn = {0254-0584},
	abstract = {By utilizing a group contribution method (GCM) by specifying the number of functional groups forming the molecules, estimation of some of the pivotal properties of substances becomes feasible. To broaden the scope of the predictable properties and to expand the applicability of the GCM procedure, it may be required to combine it with an equation of state. In this work, the internal energy, enthalpy, and entropy in 2000 states per material of 69 compounds from the NIST database were compared with the results of 25 different GCM-based cubic equations of state and analyzed by classes of compounds to identify the limitations of the method and to suggest the use of an equation of state for each type of compounds.
		Interestingly, equations that depend on fewer material properties tend to yield better results, especially when those properties can be estimated with high precision. In contrast, equations that rely on more parameters may be more sensitive to inaccuracies in property estimates, making them less reliable.},
	year = {2026},
	eissn = {1879-3312}
}

@article{MTMT:37020322,
	title = {Prediction of temperature-entropy diagram classes for pure fluids in organic Rankine cycles using group contribution methods},
	url = {https://m2.mtmt.hu/api/publication/37020322},
	author = {Groniewsky, Axel and Hégely, László},
	doi = {10.1016/j.fluid.2026.114705},
	journal-iso = {FLUID PHASE EQUILIBR},
	journal = {FLUID PHASE EQUILIBRIA},
	volume = {607},
	unique-id = {37020322},
	issn = {0378-3812},
	abstract = {The organic Rankine cycle is an indispensable technology in low-temperature heat recovery, where the working fluid is a critical element. It influences not only the type and design parameters of the equipment but, via the shape of the saturated liquid and vapor line, the configuration as well. Besides thermophysical and chemical properties, the selection of the ideal working fluid is also affected by the ever-growing stringency of environmental regulations. Hence, there is a growing demand to create unique, ecologically sound media. Addressing this challenge involves simultaneously optimizing molecular structure and process parameters —an endeavor often facilitated by computer-aided molecular design, applying group contribution methods. Given the frequent application of cubic equations of state (EoS) in this method, the present study investigates which of the 23 common cubic EoS should be chosen when the class of the shape of the newly designed phase curve is to be determined. The grouping is examined for the traditional 3-element and the more sensitive Györke classification. Interestingly, the findings indicate that the fewer material properties an EoS relies on, the more accurate the classification becomes, provided these properties are accurately estimated. Complex EoSs, however, may exhibit higher parameter sensitivity and, similarly to model validation, can become overfitted. Moreover, results show that achieving high accuracy in phase curve design does not necessarily equate to high classification ability, which may require the introduction of distinct indicators for classification and determining the precision of the temperature-entropy phase curve.},
	year = {2026},
	eissn = {1879-0224}
}

@article{MTMT:36462534,
	title = {Effects of the electricity consumption profile on the optimal renewable energy supply},
	url = {https://m2.mtmt.hu/api/publication/36462534},
	author = {Mayer, Martin János and Kun-Balog, Attila and Groniewsky, Axel},
	doi = {10.1016/j.enconman.2025.120797},
	journal-iso = {ENERG CONVERS MANAGE},
	journal = {ENERGY CONVERSION AND MANAGEMENT},
	volume = {348},
	unique-id = {36462534},
	issn = {0196-8904},
	abstract = {The transition to weather-dependent renewable energy sources makes managing the temporal distribution of energy demand pivotal. This paper examines how the distinct characteristics of load profiles affect the levelized cost of electricity (LCOE) and the optimal technology mix of a hybrid renewable energy system (HRES) covering a pre-defined ratio of the electricity consumption. The proposed method involves the physical modeling of photovoltaic (PV) and wind turbine (WT) power production and the joint optimization of the operation of three energy storage technologies, namely lithium iron phosphate (LFP) and sodium-sulfur (NaS) batteries and hydrogen, and the installed capacities of all components with linear programming. All results are presented as a function of the renewable coverage ratio, enabling analysis across the entire pathway of a renewable energy transition. Nine measurement-based load profiles are considered, representing all combinations of three daily and three seasonal consumption trends. The LCOE of supplying the least favorable load profile is up to 88% higher than that of the most favorable one for small-scale systems consisting of four households supplied by only PV and LFP. This difference reduces to 42% if all five technologies are included in a town-sized community, which highlights the benefits of larger-scale energy communities with a diverse technology mix. The seasonal consumption habits are found to have a greater impact on the optimal cost and sizing than daily usage behaviors. Renewable energy production has largely different costs at different parts of the year, calling for a shift in the paradigm that energy efficiency is judged based on the amount of consumed or saved energy, since changes in the temporal distributions are becoming equally important.},
	year = {2026},
	eissn = {1879-2227},
	orcid-numbers = {Mayer, Martin János/0000-0001-5631-6117}
}

@article{MTMT:34889882,
	title = {Extension of the Constantinou and Gani group contribution method with the Tochigi method through an automatic conversion procedure},
	url = {https://m2.mtmt.hu/api/publication/34889882},
	author = {Groniewsky, Axel and Hégely, László},
	doi = {10.1016/j.fluid.2024.114148},
	journal-iso = {FLUID PHASE EQUILIBR},
	journal = {FLUID PHASE EQUILIBRIA},
	volume = {584},
	unique-id = {34889882},
	issn = {0378-3812},
	year = {2024},
	eissn = {1879-0224}
}

@article{MTMT:35457635,
	title = {NaS akkumulátorok alkalmazása a lakossági villamosenergia-szektorban},
	url = {https://m2.mtmt.hu/api/publication/35457635},
	author = {Groniewsky, Axel and Kun-Balog, Attila},
	journal-iso = {ENGA},
	journal = {ENERGIAGAZDÁLKODÁS},
	volume = {65},
	unique-id = {35457635},
	issn = {0021-0757},
	year = {2024},
	pages = {2-6}
}

@article{MTMT:33879854,
	title = {Simultaneous working fluid and expander selection method for reaching low-threshold technology organic Rankine cycle (ORC) design},
	url = {https://m2.mtmt.hu/api/publication/33879854},
	author = {Groniewsky, Axel and Kustán, Réka and Imre, Attila},
	doi = {10.1002/ese3.1457},
	journal-iso = {ENERGY SCI ENG},
	journal = {ENERGY SCIENCE & ENGINEERING},
	volume = {11},
	unique-id = {33879854},
	issn = {2050-0505},
	year = {2023},
	eissn = {2050-0505},
	pages = {2330-2350},
	orcid-numbers = {Imre, Attila/0000-0003-4604-5899}
}

@article{MTMT:34023973,
	title = {Ipari projektek az Energetikai Gépek és Rendszerek Tanszéken},
	url = {https://m2.mtmt.hu/api/publication/34023973},
	author = {Sztankó, Krisztián Endre and Lezsovits, Ferenc and Groniewsky, Axel},
	journal-iso = {ENGA},
	journal = {ENERGIAGAZDÁLKODÁS},
	volume = {64},
	unique-id = {34023973},
	issn = {0021-0757},
	year = {2023},
	pages = {35-41}
}

@article{MTMT:33599677,
	title = {Efficiency Increase of Biological Methanation based Power-toMethane Technology Using Waste Heat Recovery with Organic Rankine Cycle},
	url = {https://m2.mtmt.hu/api/publication/33599677},
	author = {Groniewsky, Axel and Kustán, Réka and Imre, Attila},
	doi = {10.3311/PPch.20428},
	journal-iso = {PERIOD POLYTECH CHEM ENG},
	journal = {PERIODICA POLYTECHNICA-CHEMICAL ENGINEERING},
	volume = {66},
	unique-id = {33599677},
	issn = {0324-5853},
	year = {2022},
	eissn = {1587-3765},
	pages = {596-608},
	orcid-numbers = {Imre, Attila/0000-0003-4604-5899}
}

@article{MTMT:33105827,
	title = {Power-to-Methane technológia: műszaki összegzés és esettanulmány},
	url = {https://m2.mtmt.hu/api/publication/33105827},
	author = {Groniewsky, Axel and Kustán, Réka and Imre, Attila},
	journal-iso = {ENGA},
	journal = {ENERGIAGAZDÁLKODÁS},
	volume = {63},
	unique-id = {33105827},
	issn = {0021-0757},
	year = {2022},
	pages = {2-12},
	orcid-numbers = {Imre, Attila/0000-0003-4604-5899}
}