Heat transfer characteristics of an expanded graphite/paraffin PCM-heat exchanger used in an instantaneous heat pump water heater

Wu, Jianghong; Feng, Ying; Liu, Chaopeng; Li, Huixi

doi:10.1016/j.applthermaleng.2018.06.087

Cited by 74 publications

(9 citation statements)

References 34 publications

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“…However, solid–liquid and solid–solid PCMs are commonly used in several applications. Besides these classifications, PCMs can be further classified into three categories based on temperature range, namely low-temperature PCMs (<15°C), intermediate temperature PCMs (15–90°C), and high-temperature PCMs (>90 °C) [ 318 ]. The intermediate temperature PCMs are most popular, used in solar and energy-saving application in concrete buildings [ 319 , 320 ].…”

Section: Chemical Additives/admixturesmentioning

confidence: 99%

Review of the Effects of Supplementary Cementitious Materials and Chemical Additives on the Physical, Mechanical and Durability Properties of Hydraulic Concrete

et al. 2021

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Supplementary cementitious materials (SCMs) and chemical additives (CA) are incorporated to modify the properties of concrete. In this paper, SCMs such as fly ash (FA), ground granulated blast furnace slag (GGBS), silica fume (SF), rice husk ash (RHA), sugarcane bagasse ash (SBA), and tire-derived fuel ash (TDFA) admixed concretes are reviewed. FA (25–30%), GGBS (50–55%), RHA (15–20%), and SBA (15%) are safely used to replace Portland cement. FA requires activation, while GGBS has undergone in situ activation, with other alkalis present in it. The reactive silica in RHA and SBA readily reacts with free Ca(OH)2 in cement matrix, which produces the secondary C-S-H gel and gives strength to the concrete. SF addition involves both physical contribution and chemical action in concrete. TDFA contains 25–30% SiO2 and 30–35% CaO, and is considered a suitable secondary pozzolanic material. In this review, special emphasis is given to the various chemical additives and their role in protecting rebar from corrosion. Specialized concrete for novel applications, namely self-curing, self-healing, superhydrophobic, electromagnetic (EM) wave shielding and self-temperature adjusting concretes, are also discussed.

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Section: Chemical Additives/admixturesmentioning

confidence: 99%

Review of the Effects of Supplementary Cementitious Materials and Chemical Additives on the Physical, Mechanical and Durability Properties of Hydraulic Concrete

et al. 2021

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“…Thus, PCMs are recommended as thermal storage energy materials. Moreover, there are different types of PCMs such as solid–solid, solid–liquid, liquid–gas and solid–gas 11 . Among them, the most popular and commonly used PCMs are solid–solid and solid–liquid.…”

Section: Introductionmentioning

confidence: 99%

Microencapsulation of stearic acid with SiO2 shell as phase change material for potential energy storage

Ishak

Mandal

Lee

et al. 2020

Sci Rep

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Stearic acid (SA) is being used as phase change material (PCM) in energy storage applications. In the present study, the microencapsulation of SA with SiO2 shell was carried out by sol–gel method. Different amounts of SA (5, 10, 15, 20, 30 and 50 g) were taken against 10 ml of tetraethyl orthosilicate (TEOS) for encapsulation. The synthesized microencapsulated PCM (MEPCM) were characterized by Fourier transform infrared spectroscope (FT-IR), X-Ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The characterization results showed that SA was successfully encapsulated by SiO2. Thermogravimetric analysis (TGA) exhibited better thermal stability of the MEPCM than SA. The enthalpy values of MEPCM were found to be unchanged even after 30 heating–cooling cycles by differential scanning calorimetry (DSC). The latent heats of melting and solidification of 50 g SA containing MEPCM were found to be highest i.e. 182.53 J/g and 160.12 J/g, respectively among all microencapsulated samples. The encapsulation efficiency values were calculated using thermal data and the efficiency was found to be highest i.e. 86.68% in the same sample.

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“…Whalley and Ebrahimi [20] considered the modelling and dynamic analysis of shell and tube heat exchangers in their contribution. Wu et al [21] experimentally investigated the feasibility of an expandedgraphite paraffin phase change material heat exchanger operating as a condenser in an instant air source heat pump water heater. Xia et al [22] analyzed the heat exchanger network synthesis problem based on entransy theory.…”

Section: Introductionmentioning

confidence: 99%

Study of Heat and Mass Transfer Through an Earth to Air Heat Exchanger Equipped with Fan in South West of Algeria

Sakhri¹,

Menni²,

Chamkha³

et al. 2019

IJHT

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Earth to air heat exchanger is a very old technique used 3000 years B.C in arid regions where that was called Qanat. In the present experimental study, the potentials of earth to air heat exchanger to provide thermal comfort for winter weather conditions in South west of Algeria described as arid region are investigated. An EAHE made of 66 meter of PVC tube and buried at 1.5 meter underground in agriculture zone equipped with 33 W fan was studied. Thermal and hygrometric analysis of air passing inside the tube form inlet to outlet was conducted. The results show the system was able to create two thermal regimes: heating regime with a gain of 13 °C (from 00h to 11h and from 17h to 23h) and cooling regime (from 12h to 16h) with 6 °C in the same day. Relative humidity was reduced by 32 % of 90 % of studied cases which stops the development of microorganism and reducing Internal Air Quality.

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Heat transfer characteristics of an expanded graphite/paraffin PCM-heat exchanger used in an instantaneous heat pump water heater

Cited by 74 publications

References 34 publications

Review of the Effects of Supplementary Cementitious Materials and Chemical Additives on the Physical, Mechanical and Durability Properties of Hydraulic Concrete

Review of the Effects of Supplementary Cementitious Materials and Chemical Additives on the Physical, Mechanical and Durability Properties of Hydraulic Concrete

Microencapsulation of stearic acid with SiO2 shell as phase change material for potential energy storage

Study of Heat and Mass Transfer Through an Earth to Air Heat Exchanger Equipped with Fan in South West of Algeria

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