Novel Simulation Algorithm for Modeling the Hysteresis of Phase Change Materials

Zastawna-Rumin, Anna; Kisilewicz, Tomasz; Berardi, Umberto

doi:10.3390/en13051200

Cited by 20 publications

(20 citation statements)

References 26 publications

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“…The functions of the change of PCM mass enthalpy during H PCM phase transformation over time were developed using the calorimetric thermogram obtained and described by the author [ 27 ]. The above approach is analogous to solving Stefan’s problem [ 6 , 59 ], except that it concerns compounds with blurred melting and solidification. For the needs of this model, a discrete accumulator grid from PCM was selected with a width of dx = dy = 5 mm.…”

Section: Methodsmentioning

confidence: 99%

“…As in the previous case, the limit is the temperature range at which the PCM phase transformation takes place. The above approach according to [59,60] is used for organic and inorganic PCMs, which are characterized by their high purity, resulting in a narrow temperature range for their phase transitions. The problem is the modeling of heat storage and distribution in PCMs that are characterized by a wide range of phase transition temperatures (e.g., 10-15 • C).…”

Section: Introductionmentioning

confidence: 99%

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Experimental Analysis of the Function of a Window with a Phase Change Heat Accumulator

Lichołai

Musiał

2020

Materials

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The article presents the results of long-term field tests and their mathematical analysis regarding the impacts of innovative phase change materials on the energy efficiency of composite windows with various glazing parameters. Research was conducted on six glazing combinations throughout the heating season in a temperate climate in Rzeszów (Poland). The empirical results obtained during the spring months showed an improvement in the monthly heat balance for windows with phase change materials compared to the reference window by as much as 34.09%. In addition, the empirical results allowed the development and verification of a mathematical model describing the transport and distribution of heat within a window with a phase change heat accumulator. The model was made using equations of non-stationary heat flow and an explicit finite difference method using calorimetric thermograms describing the phase change eutectic mixture used in the research. Carrying out the Snedecor–Fischer test proved the statistical adequacy of the developed model in 4 out of 6 tested combinations of glazing units. Good matching of the empirical and theoretical quantities was also confirmed using the quasi-Newton method. The article is a solution to the problem of the effective use of solar energy within transparent building partitions, while presenting a useful mathematical tool that determines potential thermal gains in various climatic conditions.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental Analysis of the Function of a Window with a Phase Change Heat Accumulator

Lichołai

Musiał

2020

Materials

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“…The thermal-flow behaviour in the PCM and flowing air can be described by a standard set of equations [42,43] and for the three-dimensional case, comes down to solutions of Partial Differential Equations, (PDEs), which include a mass, a momentum, and an energy equation [44]. In this context, for solving the set of equations, one of the most frequently used numerical methods, called the Finite Volume Method (FVM), [45,46] was applied.…”

Section: Numerical Modeling Of the Analyzed System With Pcm 41 Process Governing Equationsmentioning

confidence: 99%

The Use of Capsuled Paraffin Wax in Low-Temperature Thermal Energy Storage Applications: An Experimental and Numerical Investigation

et al. 2021

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The article deals with the experimental and numerical thermal-flow behaviours of a low-temperature Phase Change Material (PCM) used in Thermal Energy Storage (TES) industrial applications. The investigated PCM is a composition that consists of a mixture of paraffin wax capsuled in a melamine-formaldehyde membrane and water, for which a phase change process occurs within the temperature range of 4 °C to 6 °C and the maximum heat storage capacity is equal to 72 kJ/kg. To test the TES capabilities of the PCM for operating conditions close to real ones, a series of experimental tests were performed on cylindrical modules with fixed heights of 250 mm and different outer diameters of 15, 22, and 28 mm, respectively. The module was tested in a specially designed wind tunnel where the Reynolds numbers of between 15,250 to 52,750 were achieved. In addition, a mathematical model of the analysed processes, based on the enthalpy porosity method, was proposed and validated. The temperature changes during the phase transitions that were obtained from the numerical analyses in comparison with the experimental results have not exceeded 20% of the relative error for the phase change region and no more than 10% for the rest. Additionally, the PCM was examined while using a Scanning Electron Microscope (SEM), which indicated no changes in the internal structure during phase transitions and a homogeneous structure, regardless of the tested temperature ranges.

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“…Figures [23][24][25][26][27] show the distribution of the liquid fractions throughout the melting process with 10% (1050 s), 30% (1990 s), 50% (2800 s), 70% (3650 s) and 90% (4690 s) of the volume of the PCM being melted, respectively. In the step referring to Figure 23, with a range of a 0 to 100% liquid fraction, the following characteristics were observed: In the z = 0 and 100 mm sections, the PCM fractions near the fins were found with values around 50%; in the regions referring to the lower half of the annular and close to the external surface of the inner tube, the local liquid fraction values close to 100% were obtained.…”

Section: Liquid Fractions Fieldsmentioning

confidence: 99%

“…The energy accumulated in a PCM latent thermal system can be used in a liquid desiccant air-conditioning system to control a room's temperature and relative humidity (or absolute humidity). Many other PCM applications in buildings have been reported in the literature, such as a PCM-air heat exchanger system for the heating, ventilation, and air conditioning of buildings [25]; latent heat thermal energy storage using PCM [26]; and solar radiation in PCM cells [27].…”

Section: Introductionmentioning

confidence: 99%

Phase Change Material Melting Process in a Thermal Energy Storage System for Applications in Buildings

et al. 2020

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The development of thermal energy storage systems is a possible solution in the search for reductions in the difference between the global energy supply and demand. In this context, the ability of some materials, the so-called phase change materials (PCMs), to absorb and release large amounts of energy under specific periods and operating conditions has been verified. The applications of these materials are limited due to their low thermal conductivity, and thus, it is necessary to associate them with high-conductivity materials, such as metals, to make the control of energy absorption and release times possible. Bearing this in mind, this paper presents a numerical analysis of the melting process of a PCM into a triplex tube heat exchanger (TTHX) with finned copper tubes, which allowed for the heat transfer between a heating fluid (water) and the phase change material to power a liquid-desiccant air conditioning system. Through the analysis of the temperature fields, liquid fractions, and velocities, as well as the phase transition, it was possible to describe the material charging process; then, the results were compared with experimental data, which are available in the specialized literature, and presented mean errors of less than 10%. The total required time to completely melt the PCM was about 105.5 min with the water being injected into the TTHX at a flow rate of 8.3 L/min and a temperature of 90 °C. It was observed that the latent energy that accumulated during the melting process was 1330 kJ, while the accumulated sensitive energy was 835 kJ. The average heat flux at the internal surface of the inner tube was about 3 times higher than the average heat flux at the outer surface of the TTHX intermediate tube due to the velocity gradients that developed in the internal part of the heat exchanger, and was about 10 times more intense than those observed in the external region of the equipment.

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Novel Simulation Algorithm for Modeling the Hysteresis of Phase Change Materials

Cited by 20 publications

References 26 publications

Experimental Analysis of the Function of a Window with a Phase Change Heat Accumulator

Experimental Analysis of the Function of a Window with a Phase Change Heat Accumulator

The Use of Capsuled Paraffin Wax in Low-Temperature Thermal Energy Storage Applications: An Experimental and Numerical Investigation

Phase Change Material Melting Process in a Thermal Energy Storage System for Applications in Buildings

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