Potential of macroencapsulated PCM for thermal energy storage in buildings: A comprehensive review

Review on micro/nano phase change materials for solar thermal applications

MXene aerogel-based phase change materials toward solar energy conversion

Form-stable phase change composites: Preparation, performance, and applications for thermal energy conversion, storage and management

Phase change materials (PCMs) are gaining increasing attention and becoming popular in the thermal energy storage field. Microcapsules enhance thermal and mechanical performance of PCMs used in thermal energy storage by increasing the heat transfer area and preventing the leakage of melting materials. Nowadays, a large number of studies about PCM microcapsules have been published to elaborate their benefits in energy systems. In this paper, a comprehensive review has been carried out on PCM microcapsules for thermal energy storage. Five aspects have been discussed in this review: classification of PCMs, encapsulation shell materials, microencapsulation techniques, PCM microcapsules’ characterizations, and thermal applications. This review aims to help the researchers from various fields better understand PCM microcapsules and provide critical guidance for utilizing this technology for future thermal energy storage.

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Phase Change Material (PCM) Microcapsules for Thermal Energy Storage

Salt hydrate/expanded vermiculite composite as a form-stable phase change material for building energy storage

With the rapid development of cold chain logistics, there is a growing demand for refrigerated transportation equipment for low-temperature products, such as fresh products, chemical supplies and medical vaccines. For some products with low transport temperatures, phase change materials (PCMs) from −10 C to −40 °C are still to be developed. This paper focuses on the development of a low phase transition temperature nanofluid phase change materials (NFPCMs) with excellent thermodynamic properties, simple preparation method and low cost. 23 wt% MgCl2 eutectic solution was used as phase change material in the NFPCMs, in which Multi-walled carbon nanotubes (MWCNTs) and nucleating agents play a supportive role to reduce supercooling degree. At that, the addition of MWCNTs increases the thermal conductivity and thickener xanthan gum (XG) can prevent phase separation and agglomeration. The NFPCM with 1 wt% MWCNTs has a phase transition temperature of −34.54 °C, a phase transition enthalpy of 146.9 kJ kg−1, and thermal conductivity of 0.5344 W (m k)−1. Also, under the synergistic action of MWCNTs with CaCl2 and Ca(OH)2, the supercooling degree of NFPCM decreased to 1.82 °C, which was 89% lower than that of the pure eutectic salt solution. Furthermore, the NFPCMs still showed excellent stability after 400 thermal cycles. The results show that the NFPCMs has high latent heat, higher thermal conductivity, low supercooling degree and excellent thermal stability, which makes it have practical application value and broad development prospects in the field of the cold chain.

Preparation of a low-temperature nanofluid phase change material: MgCl2–H2O eutectic salt solution system with multi-walled carbon nanotubes (MWCNTs)

The invention discloses a heat accumulation type direct expansion photovoltaic-solar heat pump electricity and heat combined supply system and method The system comprises a compressor, a condenser, an expansion valve, a three-way valve, a photovoltaic heat storage evaporator, a first one-way valve, an air cooling evaporator and a second one-way valve; an outlet of the compressor is sequentially connected with the condenser, the expansion valve, the three-way valve, the photovoltaic heat storage evaporator, the first one-way valve and the air cooling evaporator in series through pipelines andfinally connected into an inlet of the compressor The other path of the three-way valve is directly connected with an inlet pipeline of the air cooling evaporator through the second one-way valve; the three-way valve is used as a selective switch of the two liquid working medium circulation loops; according to the system, solar energy is utilized to the maximum extent, through selection of the two loops, the photovoltaic module is protected against damage caused by the too high working temperature, meanwhile, the performance of the heat pump is improved, and household electricity can be provided while household hot water is provided

Jianmin Luo

Papers

Salt hydrate/expanded vermiculite composite as a form-stable phase change material for building energy storage

Preparation of a low-temperature nanofluid phase change material: MgCl2–H2O eutectic salt solution system with multi-walled carbon nanotubes (MWCNTs)

Heat accumulation type direct expansion photovoltaic-solar heat pump electricity and heat combined supply system and method