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Simon Furbo - One of the best experts on this subject based on the ideXlab platform.
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Demonstration of a solar combi-system utilizing stable supercooling of Sodium Acetate Trihydrate for heat storage
Applied Thermal Engineering, 2020Co-Authors: Gerald Englmair, Simon Furbo, Weiqiang Kong, Jakob Brinkø Berg, Jianhua FanAbstract:Abstract Achieving a high fraction of solar heat in heat supply for domestic buildings would reduce the use of fossil fuels for heat generation and has been a goal for a long time. Combined short and long-term heat storage has been identified as one way of achieving solar fractions higher than 50 percent in heat supply for domestic buildings. To this end, a laboratory solar heating system was built with heat-pipe tubular collectors 22.4 m2 in aperture and a heat-storage prototype consisting of a 735 L water tank and four PCM units each containing 200 kg Sodium Acetate Trihydrate (SAT) composite. The SAT composite was utilized as sensible heat storage with the additional ability to release heat of fusion on demand. Operation was demonstrated with the space heating and hot water demand patterns of a standard-size Passive House in the Danish climate. A strategy was developed to control the system. Seven operation modes enabled combined charging of water tank and PCM units, heat transfer from PCM units to the water tank when heat was in demand, and the right timing of auxiliary heating. We present the controller settings identified and the heat transfer fluid flow rates applied. Sequences of water tank charging, and single and parallel PCM unit charging were used to match the collector power available and the heat transfer limitations of the stores. During the charging of PCM units, the flow temperature was kept between 70 and 95 °C to allow continuous heat transfer rates of up to 16 kW. Peaks of up to 36 kW occurred when PCM units were added to the charging circuit. During heat transfer from PCM units to the water tank, flow temperatures were close to the SAT composite temperature and thermal power of up to 6 kW was measured. The heat stores were efficiently utilized in spring and autumn. The developed control strategy and measurement data from system demonstration will form the basis for numerical performance investigations.
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Experimental investigation of a tank-in-tank heat storage unit utilizing stable supercooling of Sodium Acetate Trihydrate
Applied Thermal Engineering, 2020Co-Authors: Gerald Englmair, Mark Dannemand, Simon Furbo, Jianhua FanAbstract:Abstract A cylindrical heat storage prototype was designed to utilize Sodium Acetate Trihydrate (SAT) composite with 2%wt. extra water and 3%wt. of liquid polymeric solution for combined short and long-term heat storage. It was manufactured with inexpensive standard components of water stores. It contained 150 l of SAT composite in the inner tank and 59 l of water in the mantle surrounding the inner tank and in a spiral heat exchanger going through the inner tank. The concept of stable supercooling of SAT and the heat transfer properties of the store filled with water or the SAT composite were studied. Results showed that 27 kWh of heat was stored between 25 °C and 90 °C, where the energy storage capacity of the composite was determined to be 21.3 kWh. This was 76% higher than for a water heat store of the same volume. After a storage period in supercooled state at ambient temperature, 11.5 kWh (long-term capacity) of heat was discharged when the SAT composite solidified. This value corresponds to a heat of fusion of 207 kJ/kg. During charge and discharge in periods with solidification, the heat exchange capacity rates did not change with increase of flow rates. With discharge flow rates of 2 l/min applied in the mantle surrounding, thermal stratification was utilized. Thus, flow temperatures higher than the average SAT composite temperature resulted in liquid state. By additional use of the spiral, the discharge power reached 15 kW. During solidification the heat transfer was constantly decreasing, which resulted in a rather low discharge power. In building applications, heat transfer limitation could be overcome by discontinuous discharge via the mantle with intervals of 2–24 h. Thus, thermal power of up to 4 kW was achieved and the outlet temperature was close to the average temperature of the SAT composite.
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A solar combi-system utilizing stable supercooling of Sodium Acetate Trihydrate for heat storage: Numerical performance investigation
Applied Energy, 2019Co-Authors: Gerald Englmair, Jianhua Fan, Christoph Moser, Hermann Schranzhofer, Simon FurboAbstract:Abstract To reduce the energy consumption of buildings significantly, a novel solar combi-system with short and long-term heat storage has been developed. A system prototype with 22.4 m2 (aperture) evacuated tubular collectors, a 735 L water tank and 4 phase change material (PCM) units each containing 150 L Sodium Acetate Trihydrate composite has been built. Experimental investigation has shown advantages of utilization of stable supercooling of Sodium Acetate Trihydrate in spring and autumn. In this paper, a newly developed numerical model was used to investigate the performance potential of the system with combined utilization of the water tank and the PCM units, including on-demand crystallization of supercooled Sodium Acetate Trihydrate composites. PCM units, the water tank and the collector circuit models were validated with measurement data from system demonstration. Space heating and hot water demand patterns of a Danish single-family Passive House with a yearly heat demand of 3723 kWh were applied. Results showed that a 56% annual solar fraction of heat supply was achieved with the prototype specifications. A 69% solar fraction could be achieved with an optimized scenario including a 15% increased hot water demand. Sensitivity analysis of component sizing showed that PCM units of 200 L can be more efficiently used with a 0.6 m3 water tank. Optimal solar collector array tilt was 70°. Aperture areas between 12.8 and 22.4 m2 were found adequate for frequent utilization of a PCM volume up to 1 m3. Thus, the PCM heat storage capacity could be utilized at least 5.5 times a year. With a 22.4 m2 collector area and 5 PCM units of 200 L each, a solar fraction of 71% was calculated for the annual heat supply. Assuming full charge of a 0.6 m3 water tank and 2.8 m3 of Sodium Acetate Trihydrate composite by electricity at the beginning of the year, the system could run 18 days without need for auxiliary heating. Thus, in periods without solar collector power available, generation maxima of wind power could be utilized. In conclusion, building heat demand could be covered close to 100% by renewable energy resources.
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Design and functionality of a segmented heat-storage prototype utilizing stable supercooling of Sodium Acetate Trihydrate in a solar heating system
Applied Energy, 2018Co-Authors: Gerald Englmair, Mark Dannemand, Simon Furbo, Christoph Moser, Jianhua FanAbstract:Abstract A solar heating system with 22.4 m2 of solar collectors, a heat storage prototype consisting of four 200 kg phase-change material (PCM) storage units, and a 735 L water tank was designed to improve solar heat supply in single-family houses. The PCM storage utilized stable supercooling of Sodium Acetate Trihydrate composites to conserve the latent heat of fusion for long-term heat storage. A control strategy directed heat from a solar collector array to either the PCM storage or a water buffer storage. Several PCM units had to be charged in parallel when the solar collector output peaked at 16 kW. A single unit was charged with 27.4 kWh of heat within four hours on a sunny day, and the PCM temperature increased from 20 °C to 80 °C. The sensible heat from a single PCM unit was transferred to the water tank starting with about 32 kW of thermal power after it had fully melted at 80 °C. A mechanical seed crystal injection device was used to initialize the crystallisation of the Sodium Acetate Trihydrate after it had supercooled to room temperature. The unit discharge during solidification peaked at 8 kW. Reliable supercooling was achieved in three of the four units. About 80% of latent heat of fusion was transferred from PCM units after solidification of supercooled Sodium Acetate Trihydrate to the water tank within 5 h. Functionality tests with practical operation conditions on the novel, modular heat-storage configuration showed its applicability for domestic hot water supply and space heating.
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Porosity and density measurements of Sodium Acetate Trihydrate for thermal energy storage
Applied Thermal Engineering, 2018Co-Authors: Mark Dannemand, Jakob Berg Johansen, Christoph Moser, Hermann Schranzhofer, Mónica Delgado, Ana Lázaro, Conchita Peñalosa, Carsten Gundlach, Camilla Himmelstrup Trinderup, Simon FurboAbstract:Abstract Sodium Acetate Trihydrate (SAT) can be used as phase change material in latent heat storage with or without utilizing supercooling. The change of density from liquid to solid state leads to formation of cavities inside the bulk SAT during solidification. Samples of SAT which had solidified from supercooled state at ambient temperature and samples which had solidified with a minimal degree supercooled were investigated. The temperature dependent densities of liquid and the two types of solid SAT were measured with a density meter and a thermomechanical analyzer. The cavities formed inside samples of solid SAT, which had solidified after a high or minimal degree of supercooling, were investigated by X-ray scanning and computer tomography. The apparent density of solid SAT depended on whether it solidified from a supercooled state or not. A sample which solidified from a supercooled liquid contained 15% cavities and had a density of 1.26 g/cm 3 at 25 °C. SAT which had solidified with minimal supercooling contained 9% cavities and had a density of 1.34 g/cm 3 at 25 °C. The apparent densities of the solid SAT samples were significant lower than the value of solid SAT reported in literature of 1.45 g/cm 3 . The density of liquid and supercooled SAT with extra water was also determined at different temperatures.
Nan Zhang - One of the best experts on this subject based on the ideXlab platform.
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Experimental investigation on the supercooling and heat conduction of Sodium Acetate Trihydrate/copper foam/YSZ composite phase change material
Journal of Thermal Analysis and Calorimetry, 2020Co-Authors: Yanlin Song, Yanping Yuan, Li Yang, Nan ZhangAbstract:In this study, yttrium-stabilized zirconia (YSZ) was firstly used as a nucleating agent and copper foam as the matrix to simultaneously reduce the supercooling degree and improve the thermal conductivity of Sodium Acetate Trihydrate (SAT). The SAT/copper foam/YSZ composite phase change material (PCM) was prepared by ball milling and melting impregnation method. The influences of content of YSZ on supercooling degree of SAT and porosity of copper foam on thermal conductivity of SAT were studied experimentally. The step-cooling curve method results indicated that the supercooling of SAT can be eliminated by 0.8 mass% YSZ without any chemical interaction between SAT and YSZ. The thermal conductivity test and heat transfer test results of SAT/copper foam/YSZ composite PCM indicated that copper foam increases the thermal conductivity of SAT. The thermal conductivity of SAT/copper foam/YSZ composite PCM was 5.9, 6.9 and 9.4 times as that of pure SAT when the porosity of copper foam was 8 ppi, 15 ppi and 40 ppi. Moreover, the volume energy storage density of SAT/copper foam/YSZ composite PCMs was calculated as 448.6–473.0 MJ m−3, which was 2.09–2.20 times as that of water.
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experimental investigation on the supercooling and heat conduction of Sodium Acetate Trihydrate copper foam ysz composite phase change material
Journal of Thermal Analysis and Calorimetry, 2020Co-Authors: Yanlin Song, Yanping Yuan, Li Yang, Nan ZhangAbstract:In this study, yttrium-stabilized zirconia (YSZ) was firstly used as a nucleating agent and copper foam as the matrix to simultaneously reduce the supercooling degree and improve the thermal conductivity of Sodium Acetate Trihydrate (SAT). The SAT/copper foam/YSZ composite phase change material (PCM) was prepared by ball milling and melting impregnation method. The influences of content of YSZ on supercooling degree of SAT and porosity of copper foam on thermal conductivity of SAT were studied experimentally. The step-cooling curve method results indicated that the supercooling of SAT can be eliminated by 0.8 mass% YSZ without any chemical interaction between SAT and YSZ. The thermal conductivity test and heat transfer test results of SAT/copper foam/YSZ composite PCM indicated that copper foam increases the thermal conductivity of SAT. The thermal conductivity of SAT/copper foam/YSZ composite PCM was 5.9, 6.9 and 9.4 times as that of pure SAT when the porosity of copper foam was 8 ppi, 15 ppi and 40 ppi. Moreover, the volume energy storage density of SAT/copper foam/YSZ composite PCMs was calculated as 448.6–473.0 MJ m−3, which was 2.09–2.20 times as that of water.
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Improvement of supercooling and thermal conductivity of the Sodium Acetate Trihydrate for thermal energy storage with α-Fe 2 O 3 as addictive
Journal of Thermal Analysis and Calorimetry, 2018Co-Authors: Nan Zhang, Yanping Yuan, Liangliang Sun, Xiaoling Cao, Yanlin SongAbstract:In this study, iron oxide nanoparticles (α-Fe2O3) have been firstly used as a nucleating agent, which simultaneously reduces the supercooling degree of Sodium Acetate Trihydrate (SAT) and improves its thermal conductivity. A series of SAT composite phase change materials (PCMs) for potential latent heat thermal energy storage applications were prepared by a ball milling method using carboxymethyl cellulose as a thickening agent and Sodium dodecyl sulfonate as a dispersant. In order to investigate the effect of the mass ratio of α-Fe2O3 nanoparticles on the supercooling degree of SAT, various α-Fe2O3 contents (0.2, 0.4, 0.6, 0.8, and 1.0 mass%) were added into the SAT matrix. It was found that the supercooling degree of the SAT composite PCM was reduced to 0 °C at a α-Fe2O3 content of 0.8 mass%. Furthermore, no chemical reaction between SAT and α-Fe2O3 occurred, and the presence of α-Fe2O3 had no effect on the energy storage capability of SAT. The thermal conductivity of the SAT composite PCM was improved by 22.5% due to the addition of 0.8 mass% α-Fe2O3. After 60 melting–freezing cycles, the composite PCMs retained excellent stability with a small reduction in the phase change temperature (0.33 °C) and low latent heat loss rate (0.796%).
Zhengguo Zhang - One of the best experts on this subject based on the ideXlab platform.
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a Sodium Acetate Trihydrate formamide expanded perlite composite with high latent heat and suitable phase change temperatures for use in building roof
Construction and Building Materials, 2019Co-Authors: Rui Huang, Jinxin Feng, Ziye Ling, Xiaoming Fang, Zhengguo ZhangAbstract:Abstract Introducing a phase change material (PCM) with large latent heat, low thermal conductivity, and appropriate phase change temperatures into building roof favors reducing indoor temperature fluctuation and increasing thermal comfort, thus helping to realize building energy conservation. Herein, a Sodium Acetate Trihydrate (SAT)-formamide (FA) mixture was combined with expanded perlite (EP) to prepare a novel composite PCM. It is shown that adding tetraSodium pyrophosphate decahydrate at a loading of 3 wt% can reduce the supercooling degree of the mixture from 34.5 °C to 0.4 °C. The obtained mixture, composed of 77.6 wt% of Sodium Acetate Trihydrate, 19.4 wt% of formamide and 3 wt% of tetraSodium pyrophosphate decahydrate, can be absorbed into EP to prepare a form-stable composite PCM at a mass fraction of 55 wt%, which has a melting point of 40.5 °C and an enthalpy of as large as 148.3 J/g. This composite PCM possesses good thermal reliability and has a thermal conductivity of as low as 0.0978 W/(m·K). The thermal performance of the composite PCM when employed in the roof of a test room was investigated and compared with those of the previously reported CaCl2·6H2O/EP composite PCM and EP. It is found that, the test room with the SAT-FA/EP composite in the roof exhibits slower temperature rise and drop rates, a reduction in the highest temperature, and an increase in thermal comfort, compared with those containing the CaCl2·6H2O/EP composite PCM and EP. The better thermal performance of the SAT-FA/EP composite is attributed to its larger latent heat and more suitable phase change temperatures for use in roof, thereby showing great potential for practical applications.
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preparation and properties of phase change temperature tuned composite phase change material based on Sodium Acetate Trihydrate urea fumed silica for radiant floor heating system
Applied Thermal Engineering, 2019Co-Authors: Wanwan Fu, Xianghui Liang, Shuangfeng Wang, Zhengguo Zhang, Yutang FangAbstract:Abstract In this work, a novel phase change temperature-tuned composite phase change material (PCM) for the PCM floor was developed by using Sodium Acetate Trihydrate-urea non-eutectic mixture as PCM and fumed silica (SiO2) as both supporting material and temperature regulator. The thermoregulation mechanism of SiO2 and the properties of the resulting composite PCM were studied. The results showed that the addition of SiO2 could adjust melting temperature of the non-eutectic mixture from 34.36 to 48.45 °C, reduce supercooling degree and prevent leakage. With SiO2 mass fraction of 30%, the composite PCM had a suitable melting temperature (35.75 °C), high latent heat (151.6 kJ·kg−1) and low supercooling degree (1.14 °C). Meanwhile, the composite PCM possessed a good form stability and excellent thermal reliability and favorable thermal conductivity. Considering the above, the novel composite PCM has a great potential for the PCM floor. It is also expected that the present work can provide a new insight into tailoring phase change temperature of PCMs.
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thermal properties enhancement and application of a novel Sodium Acetate Trihydrate formamide expanded graphite shape stabilized composite phase change material for electric radiant floor heating
Applied Thermal Engineering, 2019Co-Authors: Yutang Fang, Xianghui Liang, Shuangfeng Wang, Xuenong Gao, Yifan Ding, Yufeng Tang, Ce Jin, Zhengguo ZhangAbstract:Abstract Electric radiant floor heating system (ERFHS) with hydrate salt phase change material (PCM) as thermal storage medium owns the advantages of improving indoor comfort with high energy efficiency and favorable economic applicability. In this paper, based on Sodium Acetate Trihydrate (SAT)-formamide (FA) eutectic mixture as PCM and expanded graphite (EG) as supporting carrier, a novel SAT-FA/EG composite PCM (CPCM) for ERFHS was prepared by physical blending method. The shape stability, thermal properties and thermal reliability of the SAT-FA eutectic mixture under EG were emphatically discussed. The heat storage and release performances of a simulation room established by ERFHS integrated with such CPCM were investigated. Experimental results showed that the SAT-FA/EG composite containing 8% EG displayed high phase change enthalpy (187.6 kJ/kg), suitable phase change temperature (38.54 °C), negligible supercooling degree (0.83 °C) and eminent thermal conductivity (3.11 W/m·K), along with the excellent shape stability and thermal reliability. The simulation showed that the ERFHS with CPCM layer presented smaller indoor operative temperature fluctuation in vertical orientation and longer total thermal comfort time (12.65 h), which greatly exceeds that of the one without CPCM layer (1.836 h). All the superior characters make the obtained SAT-FA/EG composite a promising candidate for ERFHS.
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A Sodium Acetate Trihydrate-formamide/expanded perlite composite with high latent heat and suitable phase change temperatures for use in building roof
Construction and Building Materials, 2019Co-Authors: Rui Huang, Jinxin Feng, Ziye Ling, Xiaoming Fang, Zhengguo ZhangAbstract:Abstract Introducing a phase change material (PCM) with large latent heat, low thermal conductivity, and appropriate phase change temperatures into building roof favors reducing indoor temperature fluctuation and increasing thermal comfort, thus helping to realize building energy conservation. Herein, a Sodium Acetate Trihydrate (SAT)-formamide (FA) mixture was combined with expanded perlite (EP) to prepare a novel composite PCM. It is shown that adding tetraSodium pyrophosphate decahydrate at a loading of 3 wt% can reduce the supercooling degree of the mixture from 34.5 °C to 0.4 °C. The obtained mixture, composed of 77.6 wt% of Sodium Acetate Trihydrate, 19.4 wt% of formamide and 3 wt% of tetraSodium pyrophosphate decahydrate, can be absorbed into EP to prepare a form-stable composite PCM at a mass fraction of 55 wt%, which has a melting point of 40.5 °C and an enthalpy of as large as 148.3 J/g. This composite PCM possesses good thermal reliability and has a thermal conductivity of as low as 0.0978 W/(m·K). The thermal performance of the composite PCM when employed in the roof of a test room was investigated and compared with those of the previously reported CaCl2·6H2O/EP composite PCM and EP. It is found that, the test room with the SAT-FA/EP composite in the roof exhibits slower temperature rise and drop rates, a reduction in the highest temperature, and an increase in thermal comfort, compared with those containing the CaCl2·6H2O/EP composite PCM and EP. The better thermal performance of the SAT-FA/EP composite is attributed to its larger latent heat and more suitable phase change temperatures for use in roof, thereby showing great potential for practical applications.
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Thermal properties enhancement and application of a novel Sodium Acetate Trihydrate-formamide/expanded graphite shape-stabilized composite phase change material for electric radiant floor heating
Applied Thermal Engineering, 2019Co-Authors: Yutang Fang, Xianghui Liang, Shuangfeng Wang, Xuenong Gao, Yifan Ding, Yufeng Tang, Ce Jin, Zhengguo ZhangAbstract:Abstract Electric radiant floor heating system (ERFHS) with hydrate salt phase change material (PCM) as thermal storage medium owns the advantages of improving indoor comfort with high energy efficiency and favorable economic applicability. In this paper, based on Sodium Acetate Trihydrate (SAT)-formamide (FA) eutectic mixture as PCM and expanded graphite (EG) as supporting carrier, a novel SAT-FA/EG composite PCM (CPCM) for ERFHS was prepared by physical blending method. The shape stability, thermal properties and thermal reliability of the SAT-FA eutectic mixture under EG were emphatically discussed. The heat storage and release performances of a simulation room established by ERFHS integrated with such CPCM were investigated. Experimental results showed that the SAT-FA/EG composite containing 8% EG displayed high phase change enthalpy (187.6 kJ/kg), suitable phase change temperature (38.54 °C), negligible supercooling degree (0.83 °C) and eminent thermal conductivity (3.11 W/m·K), along with the excellent shape stability and thermal reliability. The simulation showed that the ERFHS with CPCM layer presented smaller indoor operative temperature fluctuation in vertical orientation and longer total thermal comfort time (12.65 h), which greatly exceeds that of the one without CPCM layer (1.836 h). All the superior characters make the obtained SAT-FA/EG composite a promising candidate for ERFHS.
Yutang Fang - One of the best experts on this subject based on the ideXlab platform.
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preparation and properties of phase change temperature tuned composite phase change material based on Sodium Acetate Trihydrate urea fumed silica for radiant floor heating system
Applied Thermal Engineering, 2019Co-Authors: Wanwan Fu, Xianghui Liang, Shuangfeng Wang, Zhengguo Zhang, Yutang FangAbstract:Abstract In this work, a novel phase change temperature-tuned composite phase change material (PCM) for the PCM floor was developed by using Sodium Acetate Trihydrate-urea non-eutectic mixture as PCM and fumed silica (SiO2) as both supporting material and temperature regulator. The thermoregulation mechanism of SiO2 and the properties of the resulting composite PCM were studied. The results showed that the addition of SiO2 could adjust melting temperature of the non-eutectic mixture from 34.36 to 48.45 °C, reduce supercooling degree and prevent leakage. With SiO2 mass fraction of 30%, the composite PCM had a suitable melting temperature (35.75 °C), high latent heat (151.6 kJ·kg−1) and low supercooling degree (1.14 °C). Meanwhile, the composite PCM possessed a good form stability and excellent thermal reliability and favorable thermal conductivity. Considering the above, the novel composite PCM has a great potential for the PCM floor. It is also expected that the present work can provide a new insight into tailoring phase change temperature of PCMs.
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thermal properties enhancement and application of a novel Sodium Acetate Trihydrate formamide expanded graphite shape stabilized composite phase change material for electric radiant floor heating
Applied Thermal Engineering, 2019Co-Authors: Yutang Fang, Xianghui Liang, Shuangfeng Wang, Xuenong Gao, Yifan Ding, Yufeng Tang, Ce Jin, Zhengguo ZhangAbstract:Abstract Electric radiant floor heating system (ERFHS) with hydrate salt phase change material (PCM) as thermal storage medium owns the advantages of improving indoor comfort with high energy efficiency and favorable economic applicability. In this paper, based on Sodium Acetate Trihydrate (SAT)-formamide (FA) eutectic mixture as PCM and expanded graphite (EG) as supporting carrier, a novel SAT-FA/EG composite PCM (CPCM) for ERFHS was prepared by physical blending method. The shape stability, thermal properties and thermal reliability of the SAT-FA eutectic mixture under EG were emphatically discussed. The heat storage and release performances of a simulation room established by ERFHS integrated with such CPCM were investigated. Experimental results showed that the SAT-FA/EG composite containing 8% EG displayed high phase change enthalpy (187.6 kJ/kg), suitable phase change temperature (38.54 °C), negligible supercooling degree (0.83 °C) and eminent thermal conductivity (3.11 W/m·K), along with the excellent shape stability and thermal reliability. The simulation showed that the ERFHS with CPCM layer presented smaller indoor operative temperature fluctuation in vertical orientation and longer total thermal comfort time (12.65 h), which greatly exceeds that of the one without CPCM layer (1.836 h). All the superior characters make the obtained SAT-FA/EG composite a promising candidate for ERFHS.
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Thermal properties enhancement and application of a novel Sodium Acetate Trihydrate-formamide/expanded graphite shape-stabilized composite phase change material for electric radiant floor heating
Applied Thermal Engineering, 2019Co-Authors: Yutang Fang, Xianghui Liang, Shuangfeng Wang, Xuenong Gao, Yifan Ding, Yufeng Tang, Ce Jin, Zhengguo ZhangAbstract:Abstract Electric radiant floor heating system (ERFHS) with hydrate salt phase change material (PCM) as thermal storage medium owns the advantages of improving indoor comfort with high energy efficiency and favorable economic applicability. In this paper, based on Sodium Acetate Trihydrate (SAT)-formamide (FA) eutectic mixture as PCM and expanded graphite (EG) as supporting carrier, a novel SAT-FA/EG composite PCM (CPCM) for ERFHS was prepared by physical blending method. The shape stability, thermal properties and thermal reliability of the SAT-FA eutectic mixture under EG were emphatically discussed. The heat storage and release performances of a simulation room established by ERFHS integrated with such CPCM were investigated. Experimental results showed that the SAT-FA/EG composite containing 8% EG displayed high phase change enthalpy (187.6 kJ/kg), suitable phase change temperature (38.54 °C), negligible supercooling degree (0.83 °C) and eminent thermal conductivity (3.11 W/m·K), along with the excellent shape stability and thermal reliability. The simulation showed that the ERFHS with CPCM layer presented smaller indoor operative temperature fluctuation in vertical orientation and longer total thermal comfort time (12.65 h), which greatly exceeds that of the one without CPCM layer (1.836 h). All the superior characters make the obtained SAT-FA/EG composite a promising candidate for ERFHS.
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thermal properties and thermal conductivity enhancement of composite phase change material using Sodium Acetate Trihydrate urea expanded graphite for radiant floor heating system
Applied Thermal Engineering, 2018Co-Authors: Ting Zou, Xianghui Liang, Shuangfeng Wang, Xuenong Gao, Zhengguo Zhang, Yutang FangAbstract:Abstract For heat exchanger used as latent heat storage system, heat storage capacity and thermal conductivity of phase change material are key indicators to determine its performance. In this paper, Sodium Acetate Trihydrate-urea non-eutectic mixture as phase change material and expanded graphite as thermal conductivity enhancer, a Sodium Acetate Trihydrate-urea/expanded graphite composite phase change material (CPCM) with both high latent heat and thermal conductivity for heat exchanger was developed by physical mixing method. The mass fractions of urea in the mixture and expanded graphite in CPCM were optimized. The crystalline phase and morphology of the obtained CPCM were characterized by X-ray diffraction and scanning electron microscope, and its thermal properties were investigated systematically. The results showed that the prepared CPCM containing 8% urea and 8% expanded graphite had a suitable phase change temperature (47.84 °C), high latent heat (223.1 kJ·kg−1), low supercooling degree (1.54 °C) as well as a satisfactory thermal conductivity (2.076 W·m−1·K−1). Moreover, the CPCM possessed a good shape stability and comparable thermal reliability. The results indicate that the obtained CPCM is an up-and-coming candidate for heat exchanger.
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Thermal properties and thermal conductivity enhancement of composite phase change material using Sodium Acetate Trihydrate–urea/expanded graphite for radiant floor heating system
Applied Thermal Engineering, 2018Co-Authors: Ting Zou, Xianghui Liang, Shuangfeng Wang, Xuenong Gao, Zhengguo Zhang, Yutang FangAbstract:Abstract For heat exchanger used as latent heat storage system, heat storage capacity and thermal conductivity of phase change material are key indicators to determine its performance. In this paper, Sodium Acetate Trihydrate-urea non-eutectic mixture as phase change material and expanded graphite as thermal conductivity enhancer, a Sodium Acetate Trihydrate-urea/expanded graphite composite phase change material (CPCM) with both high latent heat and thermal conductivity for heat exchanger was developed by physical mixing method. The mass fractions of urea in the mixture and expanded graphite in CPCM were optimized. The crystalline phase and morphology of the obtained CPCM were characterized by X-ray diffraction and scanning electron microscope, and its thermal properties were investigated systematically. The results showed that the prepared CPCM containing 8% urea and 8% expanded graphite had a suitable phase change temperature (47.84 °C), high latent heat (223.1 kJ·kg−1), low supercooling degree (1.54 °C) as well as a satisfactory thermal conductivity (2.076 W·m−1·K−1). Moreover, the CPCM possessed a good shape stability and comparable thermal reliability. The results indicate that the obtained CPCM is an up-and-coming candidate for heat exchanger.
Yanping Yuan - One of the best experts on this subject based on the ideXlab platform.
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Experimental investigation on the supercooling and heat conduction of Sodium Acetate Trihydrate/copper foam/YSZ composite phase change material
Journal of Thermal Analysis and Calorimetry, 2020Co-Authors: Yanlin Song, Yanping Yuan, Li Yang, Nan ZhangAbstract:In this study, yttrium-stabilized zirconia (YSZ) was firstly used as a nucleating agent and copper foam as the matrix to simultaneously reduce the supercooling degree and improve the thermal conductivity of Sodium Acetate Trihydrate (SAT). The SAT/copper foam/YSZ composite phase change material (PCM) was prepared by ball milling and melting impregnation method. The influences of content of YSZ on supercooling degree of SAT and porosity of copper foam on thermal conductivity of SAT were studied experimentally. The step-cooling curve method results indicated that the supercooling of SAT can be eliminated by 0.8 mass% YSZ without any chemical interaction between SAT and YSZ. The thermal conductivity test and heat transfer test results of SAT/copper foam/YSZ composite PCM indicated that copper foam increases the thermal conductivity of SAT. The thermal conductivity of SAT/copper foam/YSZ composite PCM was 5.9, 6.9 and 9.4 times as that of pure SAT when the porosity of copper foam was 8 ppi, 15 ppi and 40 ppi. Moreover, the volume energy storage density of SAT/copper foam/YSZ composite PCMs was calculated as 448.6–473.0 MJ m−3, which was 2.09–2.20 times as that of water.
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experimental investigation on the supercooling and heat conduction of Sodium Acetate Trihydrate copper foam ysz composite phase change material
Journal of Thermal Analysis and Calorimetry, 2020Co-Authors: Yanlin Song, Yanping Yuan, Li Yang, Nan ZhangAbstract:In this study, yttrium-stabilized zirconia (YSZ) was firstly used as a nucleating agent and copper foam as the matrix to simultaneously reduce the supercooling degree and improve the thermal conductivity of Sodium Acetate Trihydrate (SAT). The SAT/copper foam/YSZ composite phase change material (PCM) was prepared by ball milling and melting impregnation method. The influences of content of YSZ on supercooling degree of SAT and porosity of copper foam on thermal conductivity of SAT were studied experimentally. The step-cooling curve method results indicated that the supercooling of SAT can be eliminated by 0.8 mass% YSZ without any chemical interaction between SAT and YSZ. The thermal conductivity test and heat transfer test results of SAT/copper foam/YSZ composite PCM indicated that copper foam increases the thermal conductivity of SAT. The thermal conductivity of SAT/copper foam/YSZ composite PCM was 5.9, 6.9 and 9.4 times as that of pure SAT when the porosity of copper foam was 8 ppi, 15 ppi and 40 ppi. Moreover, the volume energy storage density of SAT/copper foam/YSZ composite PCMs was calculated as 448.6–473.0 MJ m−3, which was 2.09–2.20 times as that of water.
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Improvement of supercooling and thermal conductivity of the Sodium Acetate Trihydrate for thermal energy storage with α-Fe 2 O 3 as addictive
Journal of Thermal Analysis and Calorimetry, 2018Co-Authors: Nan Zhang, Yanping Yuan, Liangliang Sun, Xiaoling Cao, Yanlin SongAbstract:In this study, iron oxide nanoparticles (α-Fe2O3) have been firstly used as a nucleating agent, which simultaneously reduces the supercooling degree of Sodium Acetate Trihydrate (SAT) and improves its thermal conductivity. A series of SAT composite phase change materials (PCMs) for potential latent heat thermal energy storage applications were prepared by a ball milling method using carboxymethyl cellulose as a thickening agent and Sodium dodecyl sulfonate as a dispersant. In order to investigate the effect of the mass ratio of α-Fe2O3 nanoparticles on the supercooling degree of SAT, various α-Fe2O3 contents (0.2, 0.4, 0.6, 0.8, and 1.0 mass%) were added into the SAT matrix. It was found that the supercooling degree of the SAT composite PCM was reduced to 0 °C at a α-Fe2O3 content of 0.8 mass%. Furthermore, no chemical reaction between SAT and α-Fe2O3 occurred, and the presence of α-Fe2O3 had no effect on the energy storage capability of SAT. The thermal conductivity of the SAT composite PCM was improved by 22.5% due to the addition of 0.8 mass% α-Fe2O3. After 60 melting–freezing cycles, the composite PCMs retained excellent stability with a small reduction in the phase change temperature (0.33 °C) and low latent heat loss rate (0.796%).
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experimental studies on the supercooling and melting freezing characteristics of nano copper Sodium Acetate Trihydrate composite phase change materials
Renewable Energy, 2016Co-Authors: Wenlong Cui, Yanping Yuan, Liangliang Sun, Xiaoling Cao, Xiaojiao YangAbstract:This paper reports that Nano-copper (Nano-Cu), which possesses high thermal and electrical conductivity, as an additive, can improve the supercooling properties of Sodium Acetate Trihydrate (CH3COONa·3H2O, SAT) and enhance its thermal conductivity. To investigate the effect of Nano-Cu content on the degree of supercooling of SAT, composite phase change materials containing SAT, Nano-Cu (0.4%, 0.5%, 0.6%, 0.7% and 0.8%), CMC (thickening agent) and Sodium dodecyl sulfonate (C12H25NaO3S, dispersant) were prepared. Melting-freezing experiments involving the composite materials indicated that the rate of heat transfer increased by nearly 20%. When an optimal amount of Nano-Cu (i.e., 0.5%) was added to SAT, the degree of supercooling was reduced to approximately 0.5 °C. Compared to the use of inorganic salt hydrates as nucleating agents, Nano-Cu is significantly advantageous in reducing the degree of supercooling of SAT. The maximum improvement in supercooling was observed when the melting-freezing experiment was conducted at an initial temperature of 70 °C. The thermal conductivity of the reported composite phasechange materialsis approximately 20% higher than that of pure SAT.
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Experimental studies on the supercooling and melting/freezing characteristics of nano-copper/Sodium Acetate Trihydrate composite phase change materials
Renewable Energy, 2016Co-Authors: Wenlong Cui, Yanping Yuan, Liangliang Sun, Xiaoling Cao, Xiaojiao YangAbstract:This paper reports that Nano-copper (Nano-Cu), which possesses high thermal and electrical conductivity, as an additive, can improve the supercooling properties of Sodium Acetate Trihydrate (CH3COONa·3H2O, SAT) and enhance its thermal conductivity. To investigate the effect of Nano-Cu content on the degree of supercooling of SAT, composite phase change materials containing SAT, Nano-Cu (0.4%, 0.5%, 0.6%, 0.7% and 0.8%), CMC (thickening agent) and Sodium dodecyl sulfonate (C12H25NaO3S, dispersant) were prepared. Melting-freezing experiments involving the composite materials indicated that the rate of heat transfer increased by nearly 20%. When an optimal amount of Nano-Cu (i.e., 0.5%) was added to SAT, the degree of supercooling was reduced to approximately 0.5 °C. Compared to the use of inorganic salt hydrates as nucleating agents, Nano-Cu is significantly advantageous in reducing the degree of supercooling of SAT. The maximum improvement in supercooling was observed when the melting-freezing experiment was conducted at an initial temperature of 70 °C. The thermal conductivity of the reported composite phasechange materialsis approximately 20% higher than that of pure SAT.