The water tank is most commonly a crucial energy storage device of a solar heating system. However, few existing studies have focused on the quantitative analysis of the heat discharge process of a square water tank. In this paper, a multi-units water tank with phase change material (MWT-PCM) was proposed. The dynamic heat discharge performances of the MWT-PCM and the conventional water tank both with 235.8 dm3 were compared experimentally. A validated mathematical model was established to optimize the configuration of the MWT-PCM. Results demonstrated that: (1) The water temperature of both tanks had a sharp decline at the initial stage of the heat discharge process. (2) The instantaneous residual effective heat and the instantaneous heat supply of the WMT-PCM were 127% and 45.6% higher than that of the conventional water tank on average, respectively. (3) Due to the PCM, the effective heat discharge time could be prolonged by about 90 min. (4) When the PCM was arranged in a multi-unit manner, a small flow rate operation was recommended. However, the effect of changes in the total mass of the PCM was not obvious, and thus, for the given total mass, a smaller pipe diameter was recommended.
CabezaLFChàferM.Technological options and strategies towards zero energy buildings contributing to climate change mitigation: a systematic review. Energy Build2020; 219: 110009.
2.
KasaeianABahramiLPourfayazFKhodabandehEYanW-M.Experimental studies on the applications of PCMs and nano-PCMs in buildings: a critical review. Energy Build2017; 154: 96–112.
3.
LiangF.Study on the working performance and economic analyses for the system of the solar heating and heat storage water tank with the phase change material. Chengdu: Sichuan University, 2017.
4.
KutluCZhangYElmerTSuYRiffatS.A simulation study on performance improvement of solar assisted heat pump hot water system by novel controllable crystallization of supercooled PCMs. Renew Energy2020; 152: 601–612.
5.
GhoneimAA.Comparison of theoretical models of phase-change and sensible heat storage for air and water-based solar heating systems. Solar Energy1989; 42: 209–220.
6.
LiJLongELiangFZouHMaoN.Experimental study on dynamic heat release performance of water tank with phase change materials. Energy Proc2019; 158: 5006–5013.
7.
HanYMWangRZDaiYJ.Thermal stratification within the water tank. Renew Sustain Energy Rev2009; 13: 1014–1026.
8.
WangZZhangHDouBZhangGHuangH.The thermal stratification evaluation of phase-change materials in a heat storage tank: computational fluid dynamics and experimental study. J Sol Energy Eng2020; 142: 021012.
9.
WangZZhangHHuangHDouBHuangXGoulaMA.The experimental investigation of the thermal stratification in a solar hot water tank. Renew Energy2019; 134: 862–874.
10.
ZhangZSongPFanY.Experimental investigation on the geometric structure with perforated baffle for thermal stratification of the water tank. Solar Energy2020; 203: 197–209.
11.
LafriDSemmarDHamidAOuzzaneM.Experimental investigation on combined sensible and latent heat storage in two different configurations of tank filled with PCM. Appl Therm Eng2019; 149: 625–632.
12.
HaillotDFranquetEGiboutSBédécarratsJ-P.Optimization of solar DHW system including PCM media. Appl Energy2013; 109: 470–475.
13.
FrazzicaAManzanMSapienzaAFreniAToniatoGRestucciaG.Experimental testing of a hybrid sensible-latent heat storage system for domestic hot water applications. Appl Energy2016; 183: 1157–1167.
14.
NavarroLBarrenecheCCastellARedpathDAGGriffithsPWCabezaLF.High density polyethylene spheres with PCM for domestic hot water applications: water tank and laboratory scale study. J Energy Storage2017; 13: 262–267.
15.
ZhouYYuHHeJLiSRenSHeYZhangG.Model and application of a domestic hot-water tank with a novel structure comprising a phase-change material. Build Sci2017; 33: 27–33.
16.
WangX.Investigation on designing and operation characteristic of latent heat storage water tank. Chengdu: Southwest Jiaotong University, 2013.
17.
DengJFurboSKongWFanJ.Thermal performance assessment and improvement of a solar domestic hot water tank with PCM in the mantle. Energy Build2018; 172: 10–21.
18.
LiuZ.Study on characteristics of baffled phase change material water tank. Chongqing: Chongqing Univeristy, 2016.
19.
IbáñezMCabezaLFSoléCRocaJNoguésM.Modelization of a water tank including a PCM module. Appl Therm Eng2006; 26: 1328–1333.
20.
MehlingHCabezaLFHippeliSHieblerS.PCM-module to improve hot water heat stores with stratification. Renew Energy2003; 28: 699–711.
21.
CabezaLFIbáñezMSoléCRocaJNoguésM.Experimentation with a water tank including a PCM module. Solar Energy Mater Solar Cells2006; 90: 1273–1282.
22.
LiHCaoCFengGZhangRHuangK.A numerical study on heat storage water tank containing phase change materials for air source heat pump systems. Energy Storage Sci Technol2016; 5: 101–105.
23.
TalmatskyEKribusA.PCM storage for solar DHW: an unfulfilled promise?Solar Energy2008; 82: 861–869.
24.
NajafianAHaghighatFMoreauA.Integration of PCM in domestic hot water tanks: optimization for shifting peak demand. Energy Build2015; 106: 59–64.
25.
BouhalTEl RhafikiTKousksouTJamilAZeraouliY.PCM addition inside solar water heaters: numerical comparative approach. J Energy Storage2018; 19: 232–246.
26.
PadovanRManzanM.Genetic optimization of a PCM enhanced storage tank for solar domestic hot water systems. Solar Energy2014; 103: 563–573.
27.
FengGZhuYHuangKLiangDLiuX.Heat storage and release performance simulation and multiple factors analysis in phase change energy storage tank. J Shenyang Jianzhu Univ2016; 32: 675–683.
28.
TeamahHMLightstoneMFCottonJS.An alternative approach for assessing the benefit of phase change materials in solar domestic hot water systems. Solar Energy2017; 158: 875–888.
29.
ShirinbakhshMMirkhaniNSajadiB.A comprehensive study on the effect of hot water demand and PCM integration on the performance of SDHW system. Solar Energy2018; 159: 405–414.
30.
BayomyADaviesSSaghirZ.Domestic hot water storage tank utilizing phase change materials (PCMs): numerical approach. Energies2019; 12: 2170.
31.
HeZWangXDuXAmjadMYangLXuC.Experiments on comparative performance of water thermocline storage tank with and without encapsulated paraffin wax packed bed. Appl Therm Eng2019; 147: 188–197.
32.
HeZWangXDuXXuCYangL.Cyclic characteristics of water thermocline storage tank with encapsulated PCM packed bed. Int J Heat Mass Transfer2019; 139: 1077–1086.
33.
YuHGaoJYaoC.Heat release performance of heat storage water tank with phase-change material in solar drying system. Trans Chin Soc Agricult Eng2015; 31: 207–211.
34.
LiangFZhangYLiuQJinZZhaoXLongE.Experimental study on thermal energy storage performance of water tank with phase change materials in solar heating system. Proc Eng2017; 205: 3027–3034.
35.
XieLLvYLuJLiYLiuSZouQWangX.Heating storage performance of a water tank–combined phase change material: an experimental case study. Adv Mech Eng2017; 9: 1–13.
36.
LuSZhangTChenY.Study on the performance of heat storage and heat release of water storage tank with PCMs. Energy Build2018; 158: 1770–1780.
37.
ZhouZLiuJWangCHuangXGaoFZhangSYuB.Research on the application of phase-change heat storage in centralized solar hot water system. J Clean Product2018; 198: 1262–1275.
38.
MoCotPRC.Technical specification for floor radiant heating. Beijing: China Architecture & Building Press, 2004.
39.
XieC.The analysis of FEM and FVM for incompressible viscous flows. Chengdu: Sichuan University, 2005.
40.
StephensonG.Partial differential equations for scientists and engineers. London: Imperial College Press, 1996.
41.
AndersonJD.Jr.Computational fluid dynamics: the basic with applications. Beijing: Tsinghua University Press, 2002.
42.
Real-FernandezANavarro-EsbriJMota-BabiloniABarragan-CerveraADomenechLSanchezFMaiorinoAApreaC.Modeling of a PCM TES tank used as an alternative heat sink for a water chiller. Analysis of performance and energy savings. Energies2019; 12: 3652.
43.
MousaHNaserJHoucheO.Using PCM as energy storage material in water tanks: theoretical and experimental investigation. J Energy Storage2019; 22: 1–7.
