Robert Santa

Robert Santa
University od Dunaújváros

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26
Publications
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244
Citations

Publications

Publications (26)
Article
Fifth-generation district heating systems have appeared in the heating supply of modern cities. There is a growing demand for the use of renewable energy sources, the most significant of which is geothermal energy. Implementing district heating systems is very costly, and reducing investment and operating costs requires accurate forecasting of expe...
Article
The paper presents the determination of the simultaneity factor in district heating systems based on the simultaneous heat demand level of a group of consumers. The simultaneity factor is formed on a probability theory basis, involving a prescribed risk. The simultaneity factor is a ratio that indicates the proportion of the aggregated nominal heat...
Article
Full-text available
This study examines the economic optimisation of existing district heating systems. A new approach has been taken to solving a long-standing problem. The authors describe the input-output model of the system, the balance equations for the thermal equilibrium of the system, and the heat transfer system. From the balance equations of the series-conne...
Article
Full-text available
This research article presents an energy- efficient smart home heating system that uses a renew-able energy source and incorporates fuzzy control design. The objective of the study is to design a heating system that optimizes energy consumption while providing a comfortable indoor temperature. The main methods used in the study include the integrat...
Article
Full-text available
In response to the problem of increasing climate change and energy security, investment in renewable energy sources has increased significantly both in Europe and globally. Wind and solar power plants are expected to be the largest contributors to global decarbonization, ranking first and second in projected capacity by 2050. As all power plants ha...
Article
Application of fuzzy control has been observed in various engineering fields due to its ability to handle uncertainties and non-linearities. In this study, the advantages of using fuzzy control in heat pump systems are being investigated. Specifically, the performance of a heat pump system with a conventional proportional-integral-derivative (PID)...
Preprint
Full-text available
In response to the problem of increasing climate change and energy security, investment in renewable energy sources has increased significantly both in Europe and globally. Wind and solar power plants are expected to be the largest contributors to global decarbonization, ranking first and second in projected capacity by 2050. Since all power plants...
Article
Full-text available
The use of heat pumps is increasing worldwide, and knowledge of their properties is becoming more and more important. Although numerous tests regarding heat pumps have been performed, due to the large number of influencing variables, the entire range of input parameters is not covered, and there is no overall picture regarding the range of the coef...
Conference Paper
Full-text available
The compressor plays a significant role in the structural design and operation of heat pump, as it greatly affects the energy efficiency of the equipment. The mathematical equation of the compressor was presented in our work, which is described by coupled differential equations. The main objective of the research is to investigate the energetic par...
Article
Full-text available
When designing a heat pump evaporator, it is necessary to use correlations that ensure small deviations of the designed and realized process parameters for specific input data. The aim of the work is to propose a suitable mathematical model for the physical process in the tubular evap-orator of the heat pump. The applicability of the proposed mathe...
Article
Full-text available
The rise in prices of traditional energy sources, the high dependence of many countries on their import, and the associated need for security of supply have led to large investments in new capacity of wind power plants. Although wind power generation is a mature technology and levelized cost of electricity low, there is still room for its improveme...
Article
Full-text available
The aim of this study was to develop a mathematical model with lumped parameters to investigate the energetic parameters of the heat pump with an internal heat exchanger (IHX). The developed mathematical model is validated with 25 tests using R134a as a working fluid. The results show that the maximum prediction error between the modeled and experi...
Article
Full-text available
The presence of the lubricant POE 68 in the refrigeration system changes the thermophysical properties of the refrigerant, which significantly affects the heat transfer and the hydraulic processes. The purpose of this research is to investigate the thermodynamic properties of the R152a, R125, R134a and R123 refrigerant and POE 68 lubricant mixtures...
Article
Full-text available
This research presents an energy performance analysis of the heat pump system with internal heat exchanger (IHX). The mathematical model of the heat pump outlined in this paper has been created by the author, it is steady-state with lumped parameters. The experimental validation of the model has been carried out using R1234yf and R134a as refrigera...
Article
Full-text available
Coordinate measuring machines are devised for most complex measurements. Besides their dimension measuring abilities, the CNC operated machines can measure geometrical characteristics of form, such as straightness, roundness, cylindricity, etc. These are vital features currently, when inspection needs to submit very thorough reports not only on the...
Article
The purpose of the presented research is to develop an overall mathematical model, which will allow for a more precise simulation of the operation of a water-to-water heat pump system, having in mind its thermodynamics, fluid mechanics and heat transfer processes. The simulation allows the prediction of the parameters of the state at each and every...
Article
Full-text available
The purpose of this study is to produce a mathematical model to describe the operation of a water-to-water heat pump system for steady-state condition. The set-up model is deterministic. It consists of distributed as well as lumped parameters. The proposed mathematical models of heat exchangers were described by coupled differential equations, whil...
Article
Full-text available
In our earlier studies, it has been stated that the validity and limits of correlations developed for the calculation of heat transfer processes in the evaporator and condenser of heat pumps are not published in general. The values yielded for model structures and process characteristics indicate extreme ranges of standard deviation. While the desc...
Article
The article aims to present, analyze and select two-phase condensation heat transfer coefficients for the refrigerant-side in the condenser of the heating and cooling system of a heat pump. The heat transfer models are analyzed for condensation in horizontal smooth tubes. The mathematical models published by various authors refer to the range of he...
Article
Full-text available
This paper presents the analysis of the structure of a heat pump heating system. The water-water heat pump components of energy input to output and economic factors in decision-making are described in this work.
Article
The author introduces and analyses the two-phase pressure drop correlation for refrigerant R134a in the condenser of a heat pump heating-cooling system. The following correlation will be included: the Lockhart and Martinelli, Friedel, Chrishom, Tran et al, Wang et al. and the Wilson et al. The previously mentioned correlations were analyzed numeric...

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