Experimental Investigation of the Apparent Thermal Conductivity of Microencapsulated Phase-Change-Material Slurry at the Phase-Transition Temperature

Dutkowski, Krzysztof; Kruzel, Marcin

doi:10.3390/ma14154124

Cited by 16 publications

(9 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the field of solar energy, PCM is commonly used as a heat accumulator in tanks that act as thermal energy storage [13][14][15][16][17]; building partitions as a filling of empty spaces or addition to cement, paint, plaster [18][19][20] reducing daily room temperature fluctuations; in photovoltaic panels (PV-PCM) as a back layer limiting excessive heating of the module, which reduces its efficiency [21][22][23][24][25]; and as an addition to the working fluid in the integrated photovoltaic thermal system (PVT), cooling the photovoltaic panels and at the same time transferring heat to the storage tanks [26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

Experimental Studies of the Influence of Microencapsulated Phase Change Material on Thermal Parameters of a Flat Liquid Solar Collector

2021

Self Cite

View full text Add to dashboard Cite

The article presents the results of preliminary research aimed at determining the possibility of using microencapsulated phase change material (mPCM) slurries as a working fluid in installations with a flat liquid solar collector. In the tests, the following were used as the working fluid: water (reference liquid) and 10% wt. and 20% wt. of an aqueous solution of the product under the trade name MICRONAL® 5428 X. As the product contained 43% mPCM, the mass fraction of mPCM in the working liquid was 4.3% and 8.6%, respectively. The research was carried out in laboratory conditions in the range of irradiance I = 250–950 W/m2. Each of the three working fluids flowed through the collector in the amount of 20 kg/h, 40 kg/h, and 80 kg/h. The working fluid was supplied to the collector with a constant temperature Tin = 20 ± 0.5 °C. It was found that the temperature of the working fluid at the collector outlet increases with the increase in the radiation intensity, but the temperature achieved depended on the type of working fluid. The greater the share of mPCM in the working liquid, the lower the temperature of the liquid leaving the solar collector. It was found that the type of working fluid does not influence the achieved thermal power of the collector. The negative influence of mPCM on the operation of the solar collector was not noticed; the positive aspect of using mPCM in the solar installation should be emphasized—the reduced temperature of the medium allows the reduction in heat losses to the environment from the installation, especially in a low-temperature environment.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental Studies of the Influence of Microencapsulated Phase Change Material on Thermal Parameters of a Flat Liquid Solar Collector

2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…MPCM slurry is presented in Figure 3. The physical and chemical properties of the HFE 7000 refrigerant are presented in [36], while the properties of the MPCM slurry, i.e., viscosity, density, heat conductivity, specific heat, and heat of fusion, as well as the procedure for their determination have been presented in a number of previous studies [38][39][40][41][42].…”

Section: Data Reductionmentioning

confidence: 99%

The Effect of Microencapsulated PCM Slurry Coolant on the Efficiency of a Shell and Tube Heat Exchanger

et al. 2022

Self Cite

View full text Add to dashboard Cite

This paper describes the results of experimental studies on heat transfer in a shell and tube heat exchanger during the phase changes of the HFE 7000 refrigerant. The studies were performed using a mixture of water and a microencapsulated phase change material as a coolant. HFE 7000 refrigerant condenses on the external surface of the copper tube, while a mixture of water and phase change materials flows through the channels as coolant. Currently, there is a lack of research describing cooling using phase change materials in heat exchangers. There are a number of publications describing the heat exchange in heat exchangers during phase changes under air or water cooling. Therefore, the research hypothesis was adopted that the use of mixed water and microencapsulated material as a heat transfer fluid would increase the heat capacity and contribute to the enhancement of the heat exchange in the heat exchanger. This will enable an increase in the total heat transfer coefficient and the heat efficiency of the exchanger. Experimental studies describe the process of heat transfer intensification in the above conditions by using the phase transformation of the cooling medium melting. The test results were compared with the results of an experiment in which pure water was used as the reference liquid. The research was carried out in a wide range of refrigerant and coolant parameters: ṁr = 0.0014–0.0015 kg·s−1, ṁc = 0.014–0.016 kg·s−1, refrigerant saturation temperature Ts = 55–60 °C, coolant temperature at the inlet Tcin = 20–32 °C, and heat flux density q = 7000–7450 W·m−1. The obtained results confirmed the research hypothesis. There was an average of a 13% increase in the coolant heat transfer coefficient, and the peak increase in αc was over 24%. The average value of the heat transfer coefficient k increased by 5%, and the highest increases in the value of k were noted at Tin = 27 °C and amounted to 9% in relation to the reference liquid.

show abstract

“…The authors published the thermodynamic and physicochemical properties of mPCM slurry used during the research. The density [34], heat of fusion and specific heat [35], the heat conduction coefficient [36], and the viscosity of the slurry [37] were determined. Figure 3 shows the characteristics of the viscosity of the slurry with a concentration of 8.6% mPCM (used in the tests) as a function of temperature and shear rate.…”

Section: Working Fluidmentioning

confidence: 99%

Experimental Studies of the Effect of Microencapsulated PCM Slurry on the Efficiency of a Liquid Solar Collector

2022

Self Cite

View full text Add to dashboard Cite

A phase change material (PCM) is used as a substance filling in a heat store, due to the possibility of accumulating a significant amount of latent heat—the heat of phase transformation. Knowledge about the practical use of the working fluid, with the addition of a phase change substance, in heat exchange systems is limited The paper presents the results of preliminary research aimed at determining the possibility of using microencapsulated phase change material slurry (mPCM) as a working fluid in installations with a flat liquid solar collector, and the potential benefits as a result. The following were used as the working fluid during the tests: water (reference liquid), and a slurry of microencapsulated PCM. The mass fraction of mPCM in the working liquids is 4.3% and 8.6%, respectively. The research was carried out in laboratory conditions, in the range of radiation intensity G = 270–880 W/m2. The mass flux of each of the three working fluids in the collector is 30 kg/h, 40, kg/h, 60 kg/h, and 80 kg/h. Two main advantages of using mPCM as an additive to the working liquid are found: 1. in the entire range of thermal radiation intensity, the increase in the thermal efficiency of the collector fed with slurries is 4% with 4.3% mPCM in the slurry, and 6% with 8.6% mPCM in the slurry (for = 80 kg/h); 2. the slurry is characterized by a lower temperature at the outlet from the collector as compared to the water with the same thermal and flow parameters, which reduces heat losses to the environment both from the collector and other elements of the installation, as a result of excessive heating of the working liquid.

show abstract

Experimental Investigation of the Apparent Thermal Conductivity of Microencapsulated Phase-Change-Material Slurry at the Phase-Transition Temperature

Cited by 16 publications

References 42 publications

Experimental Studies of the Influence of Microencapsulated Phase Change Material on Thermal Parameters of a Flat Liquid Solar Collector

Experimental Studies of the Influence of Microencapsulated Phase Change Material on Thermal Parameters of a Flat Liquid Solar Collector

The Effect of Microencapsulated PCM Slurry Coolant on the Efficiency of a Shell and Tube Heat Exchanger

Experimental Studies of the Effect of Microencapsulated PCM Slurry on the Efficiency of a Liquid Solar Collector

Contact Info

Product

Resources

About