Influence of the Heating and Cooling Rate on Thermal Performance of Cement-Lime Plaster with PCM Admixture

2016 ◽  
Vol 677 ◽  
pp. 150-154
Author(s):  
Jan Fořt ◽  
Anton Trník ◽  
Zbyšek Pavlík

Thermal energy storage represents an important aspect of building energy conservation. Unfortunately, modern buildings with lightweight building envelopes not provide sufficient heat storage capacity and indoor overheating is a common problem, mostly solved by high performance air conditioning that leads to the higher electricity consumption. Here, Phase Change Materials (PCMs) that allow significant heat storage or release when undergo phase transition can find use. On this account, a detailed testing of a new type of cement-lime plaster modified by PCM admixture with respect to the temperature change rate is presented in the paper. The studied material is based on commercial dry plaster mixture that is modified by microencapsulated polymer PCM admixture. For characterization of the developed material, measurement of basic physical and mechanical properties is done. Within the DSC analysis, the researched material is exposed to the temperature loading ranging from 0 °C to 40 °C, with the temperature change rate of 1, 5 and 10 °C/min respectively. On the basis of DSC tests, temperature of phase change and its corresponding enthalpy are determined. The obtained data show the effect of heating and cooling mode on materials performance in the form of a significant shift of DSC curves. This effect is evaluated and applicability of incorporated PCM admixture for the use in thermal energy storage plasters is discussed.

2019 ◽  
Vol 111 ◽  
pp. 01100
Author(s):  
Rok Koželj ◽  
Žiga Ahčin ◽  
Eva Zavrl ◽  
Uroš Stritih

One of the great challenges in the energy sector represents retrofit of residential buildings where 3/4 of buildings in Europe are residential. To reduce energy consumption and increase the use of renewables in existing residential buildings a holistic approach of retrofit with interconnected technological system is needed. In the present paper energy toolkit based on the synergetic interaction between technologies integrated in the system for holistic retrofit of residential buildings which is under development within HEART project (HORIZON 2020) is presented. In this project step towards self-sufficient heating and cooling of building is made with an increase in on-site consumption of self-produced energy in PV from solar energy, where produced electrical energy is used also for heat pump operation. In this case thermal energy storage plays an important role for storing heat or cold for time when solar energy is not available. Improvement of sensible thermal energy storage with implemented cylindrical modules at the top of the heat storage tank and filled with phase change material is investigated experimentally. 43 litres of paraffin with phase change temperature between 27 °C and 29 °C was used in a system, what represented 15 % of total volume of heat storage tank. The results from experiment shows that thermal energy storage unit with integrated modules filled with phase change material can supply desired level of water temperature for twice as long at smaller temperature level as sensible thermal energy storage what is the consequence of higher energy density that can be stored during phase change. The advantage of phase change materials is in thermal energy storage for applications that needs narrow temperature range of supplying and storing thermal energy what is the subject matter of consideration in the case of HEART project.


2012 ◽  
Vol 134 (1) ◽  
Author(s):  
R. A. Wirtz ◽  
K. Swanson ◽  
M. Yaquinto

An important design objective that is unique to hand-held units is the need to constrain two temperatures: the maximum temperature of the electronic components and the maximum skin temperature of the hand-held unit. The present work identifies and evaluates, through parametric modeling and experiments, the passive thermal energy storage volume characteristics and phase change material composite properties that are most suitable for thermal control of small form-factor, high power-density, hand-held electronics. A one-dimensional transient analytical model, based on an integral heat balance, is formulated and benchmarked. The model accurately simulates the heat storage/recovery process in a semi-infinite, “dry” phase change material slab. Dimensional analysis identifies the time and temperature metrics and nondimensional parameters that describe the heat storage/release process. Parametric analysis illustrates how changes in these nondimensional parameters affect thermal energy storage volume thermal response.


Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5024
Author(s):  
Xiaoling Cui ◽  
Xiaoyun Du ◽  
Yanzhou Cao ◽  
Guochen Sang ◽  
Yangkai Zhang ◽  
...  

Efficient use of solar energy by thermal energy storage composites and utilizing environmentally friendly cementitious materials are important trends for sustainable building composite materials. In this study, a paraffin/low density polyethylene (LDPE) composite shape-stabilized phase change material (SSPCM) was prepared and incorporated into a sulphoaluminate cement (SAC) mortar to prepare thermal energy storage mortar. The thermal and mechanical properties of SSPCM and a SAC-based thermal energy storage material (SCTESM) were investigated. The result of differential scanning calorimeter (DSC) analysis indicates that the latent heat of SCTESM is as high as 99.99 J/g. Thermogravimetric analysis demonstrates that the SCTESM does not show significant decomposition below 145 °C. The volume stability test shows the volume shrinkage percentage of the SCTESM is less than that of pure SAC mortar and far less than that of ordinary Portland cement mortar. The SCTESM has high early strength so that the compressive strength at 1-, 3-, and 7-day curing age is up to that at 28-day curing age of 67.5%, 78.3%, and 86.7%, respectively. Furthermore, a mathematical prediction model of the SCTESM compressive strength was proposed. The investigation of latent heat storage characteristics and the thermoregulating performance reveals that SCTESMs have the excellent capacity of heat storage and thermoregulating.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Qianjun Mao ◽  
Ning Liu ◽  
Li Peng

Solar thermal energy storage (TES) is an efficient way to solve the conflict between unsteady input energy and steady output energy in concentrating solar power plant. The latent heat thermal energy storage (LHTES) system is a main method of storing thermal energy using phase change materials (PCMs). Thermal properties, that is, melting points and latent heat, are the key parameters of PCMs for the TES system. In this paper, the PCMs are classified into inorganic and organic by the chemical composition, and according to the melting point, the inorganic PCMs can be divided into three contributions: low-temperature heat storage (less than 120°C), medium-temperature heat storage (120–300°C), and high-temperature heat storage (more than 300°C). The present article focuses mainly on the recent investigations on the melting point and latent heat of PCMs via DSC setup in the solar TES systems. The results can provide a good reference for the selection and utilization of PCMs in the solar TES systems.


2000 ◽  
Author(s):  
Bing-Chwen Yang ◽  
Shr-Hau Huang ◽  
Hsiang-Hui Lin

Abstract In this paper, the feasibility of phase change material that used for thermal energy storage in the range of 400 ∼ 600°C in the form of latent heat is examined for nine different salts and eutectic salts. The Differential Scanning Calorimeter (DSC) was used to perform the quantitative measurement of the phase change temperature (Tm) and latent heat (ΔH). The thermal properties of NaCl-CaCl2 at repeated heating and cooling cycles were studied with a heating chamber. The quality observation for this phase change material was also performed with this heating chamber to understand its physical phenomena during heating and cooling process. It is found that NaCl-CaCl2 is a good candidate of thermal energy storage material for its stable properties, low cost, and no toxic. Finally, the thermal storage unit with NaCl-CaCl2 as thermal energy storage material was tested to study and evaluate its performance as the application in the waste heat recovery system.


2018 ◽  
Vol 54 (76) ◽  
pp. 10722-10725 ◽  
Author(s):  
Grace G. D. Han ◽  
Joshua H. Deru ◽  
Eugene N. Cho ◽  
Jeffrey C. Grossman

Optical regulation of heat storage in diverse sets of organic phase-change materials is demonstrated and compared.


RSC Advances ◽  
2016 ◽  
Vol 6 (98) ◽  
pp. 96327-96333 ◽  
Author(s):  
Dong Fang ◽  
Xiaomin Cheng ◽  
Yuanyuan Li ◽  
Zheng Sun

Latent heat storage proves to be one of the most efficient ways of storing thermal energy.


2014 ◽  
Vol 10 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Lavinia Gabriela Socaciu ◽  
Paula Veronica Unguresan

Abstract Phase change materials (PCMs) selection and prioritization for comfort application in buildings have a significant contribution to the improvement of latent heat storage systems. PCMs have a relatively large thermal energy storage capacity in a temperature range close to their switch point. PCMs absorb energy during the heating process as phase change takes place and release energy to the environment in the phase change range during a reverse cooling process. Thermal energy storage systems using PCMs as storage medium offer advantages such as: high heat storage capacity and store/release thermal energy at a nearly constant temperature, relative low weight, small unit size and isothermal behaviour during charging and discharging when compared to the sensible thermal energy storage. PCMs are valuable only in the range of temperature close to their phase change point, since their main thermal energy storage capacity depend on their mass and on their latent heat of fusion. Selection of the proper PCMs is a challenging task because there are lots of different materials with different characteristics. In this research paper the principles and techniques of the Analytic Hierarchy Process (AHP) are presented, discussed and applied in order to prioritize and select the proper PCMs for comfort application in buildings. The AHP method is used for solving complex decisional problems and allows the decision maker to take the most suitable decisions for the problem studied. The results obtained reveal that the AHP method can be successfully applied when we want to choose a PCM for comfort application in buildings.


2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Olakunle F Isamotu ◽  
Nicholas A Musa ◽  
Joshua B Aluko ◽  
Maclawrence A Oriaifo

Latent heat storage in salt mixture has drawn so much attention because of the salt mixture’s capability of storing   large quantity of heat when compared to single salt thereby, making it more feasible for use as phase change material.  However it is worthwhile to find out among various combination of salts forming eutectic   mixtures, the one that has the best energy storage capability by evaluating   and comparing their melting points and latent heat storage. So in this research work, four different types of eutectic mixture of   salts were prepared and experimentally   investigated for the best thermal energy storage capability.  The first eutectic mixture consists of 2.6g of LiNO3, 6.4g of NH4NO3   and 1g of NaNO3. The second eutectic mixture consists of1.75g of LiNO3,   3.9g of NH4NO3 and 1.1g of KNO3. The third one consists of 5.2g of   LiNO3, 13.7g   of NH4NO3 and 1g of NH4Cl) and the fourth one consists of 1.77g of LiNO3, 2.94g of NH4NO3,  1g of NaNO3 and 1g of NaCl. The latent heat and the melting point of the respective salt and their eutectic mixture were determined using digital differential scanning Apparatus.  The results obtained showed that the melting points and latent heats of  the first, second, third and fourth eutectic mixture  were 79.50C and 112kJ/kg,  80.50C and 114kJ/kg,  81.40C and 109kJ/kg,  84.40C and 119kJ/kg respectively.  In view of this, the eutectic mixture of 1.77g of LiNO3, 2.94g of NH4NO3, 1g of NaNO3 and 1g of NaCl with melting point of 84.40C and latent heat of 119KJ/Kg was found to possess the best thermal energy storage capability compared to others..Keywords—Eutectic mixture, Salts, Phase change materials (PCM), Latent heat storage


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