PCM Thermal Storage System Research Articles

Revolutionizing the Building Envelope: A Comprehensive Scientific Review of Innovative Technologies for Reduced Emissions

Abstract This paper reviews innovative building envelope technologies that can improve total building energy efficiency and reduce greenhouse gas emissions. The building envelope has a significant impact on energy and thermal performance, making various technologies like phase change materials, aerogel, and active and adaptive systems essential for enhancing the building envelope’s energy efficiency. Phase change materials reduce energy consumption by lowering peak heating and cooling loads, improving thermal comfort. Paraffin wax is considered the most dependable phase change material for building envelopes, as it can decrease energy consumption for heating and cooling. Study shows that active PCM thermal energy storage system can reduce room temperature by 6.8 °C in summer. Aerogel, in comparison, is recognized for its exceptional insulation capabilities and low density that minimize heat transfer and boost thermal insulation in buildings. Silica aerogel’s outstanding feature is its capacity to offer thermal performance that surpasses traditional insulation materials by 2–4 times, thereby delivering substantial energy savings of up to 35 %. Active and adaptive systems, such as smart windows and kinetic facades, enable real-time control of building envelope performance, improving energy efficiency and indoor comfort. Smart windows can lead to annual energy savings up to 35.9 kWh/m2 compared to traditional windows, and kinetic facades can reduce cooling loads for buildings up to 21 %. The review assesses various adaptive facade solutions for their suitability in diverse climate zones, versatility in application and energy efficiency. Despite the existence of some limitations and challenges, such as high costs and insufficient understanding of their long-term performance, the continuous development and deployment of these technologies can still yield a significant contribution to improving building energy efficiency and mitigating greenhouse gas emissions.

Dynamic modeling and energy analysis of renewable heating and electricity systems at residential buildings using phase change material based heat storage technologies

Several heat storage systems for domestic application can be used to promote Renewable Energy Sources (RES) penetration by storing excess energy, which would otherwise be rejected during curtailments. The present study investigates two types of PV powered latent heat storage technologies for delivering heat and/or electricity at residential buildings and compares them against a reference case which uses a conventional heat pump as a heating system, also powered by a PV. One technology involves a low temperature PCM thermal energy storage system (LT-TES) heated by either an electric resistance or a heat pump and the other technology involves an ultra-high temperature TES (UHT-TES). It is revealed that any case with heat storage is preferable for better exploiting the produced renewable energy than the conventional one which does not include heat storage. The most favorable from this aspect are the cases which include the UHT-TES, which provide both heat and electricity. Focusing exclusively on heat supply, the most preferable case from a technical performance aspect is the one which includes a heat pump and a LT-TES system, albeit not providing any electricity. On the other hand, the most advantageous only in terms of electricity supply is the case which includes the UHT-TES system.

Thermal performance analysis of MWCNT-based capric acid PCM thermal energy storage system

Effect of natural convection during the melting process of capric acid-based multi-walled carbon nanotube (MWCNT/CA) thermal energy storage system has been investigated experimentally. The temperature variations of phase change material were measured during the charging process. Effects of Stefan number and Fourier number on Nusselt number, as well as energy and exergy of the storage medium for different vol. fractions of MWCNT/CA-based phase change material, have been analysed and compared during charging process. Furthermore, the present work also extends to evaluate the thermophysical properties, i.e. thermal conductivity and specific heat capacity in liquid and solid phase of MWCNT/CA-based PCM by T-history method. Results revealed that the melting time for 0.02% vol. fraction of MWCNT/CA-based PCM is 66.66% lower compared to pure capric acid PCM. The thermal conductivity and specific heat capacity of 0.02% MWCNT/CA-based PCM obtained higher value than other samples in liquid and solid phases. Rayleigh number justified that natural convection heating process occurred within the TES system. Furthermore, the energy and exergy of 0.02% vol. fraction-based MWCNT/CA storage medium achieved 61.9% and 70.92% maximum values than pure CA phase change material, respectively. Therefore, 0.02% vol. fraction of MWCNT/CA could be suitable nanoenhanced phase change material for thermal energy storage systems.

Parametric analysis and design optimisation of PCM thermal energy storage system for space cooling of buildings

The paper presents a parametric analysis and design optimisation of an active PCM thermal energy storage system for space cooling of nearly zero-energy buildings. The design for a new space cooling system proposes a TES system composed of stand-alone PCM storage units incorporated into the building interior under the ceiling slab. Active control of the thermal energy storage is realized by night cooling of a phase change material by means of cold water flowing within a capillary pipe system. The objective of the study is to examine the effect of the system’s main parameters such as PCM layer thickness, number of parallel pipes, diameter of pipes, night cooling duration, cooling water inlet temperature and velocity under Baltic summer weather conditions. Parametric analysis is performed by using computational fluid dynamics software Ansys Fluent. Optimisation of the main parameters is carried out to determine the best combination of their values ensuring the system is able to absorb the daily thermal loads within the room and operates with minimum energy consumption for the night cooling of PCM.

Numerical and experimental Analysis of Solar Injera Baking with a PCM Heat Storage

Today, many developing countries are using biomass as their primary energy supply. However, this energy affects the environment, health and safety of women and children. In addition, utilization of this energy using traditional cooking stoves is causing indoor air pollution and in turn health problems to millions of people. To overcome such problems, efforts are being made by researchers globally and are suggesting alternative safe energy sources. This paper demonstrates solar cooker with an integrated PCM thermal storage and heat transportation loop system suitable for high temperature applications. The system has designed to address Injera baking application. Injera, a fermented flat bread type, is the most common food type served three to four times a day in Ethiopia. Other countries like Eritrea, Somalia, Sudan and Yemen also use this food. The storage system has storing capacity of heat up to 250 0 C and it can retain this heat for about two days. The storage has coupled to a polar mounted concentrator, fixed receiver and used steam heat transfer fluid. The steam circulates naturally between the evaporator and condenser in a closed loop. The paper focuses on indirect charging, simultaneous charging-discharging and discharging of the stored heat for the purpose of Injera baking. The frying pan is a custom-made aluminum plate casted by embedding a 10mm coiled stainless steel steam pipe as heating element. The pan is 500mm in diameter and 30mm thick; and the fins are 20mm in diameter and 140mm long. The fins have immersed into a 20kg PCM, which is coupled to a 1.8m diameter parabolic dish collector. The solar fryer demonstrates Injera baking for average family size. Baking is tested from the stored heat, while storage is charging. A fully charged storage has supplied enough heat to baked average household Injera demands about 19Injeras and additional breads with the remaining heat. Keywords: Solar Injera baking; PCM charging; PCM storage; Solar Injera stove design; Solar cooking; Ethiopia.

Multiple-segment metal foam application in the shell-and-tube PCM thermal energy storage system

Abstract This study describes a new approach for heat-transfer enhancement in PCM-based shell-and-tube thermal energy storage systems by employing multiple-segment or cascaded metal foam. The principle is based on the fact that temperature gradient across the PCM during the phase change reduces significantly in the heat flow direction thus affecting the heat transfer rate and resulting in a poor overall storage performance. This study suggests using multiple-segment metal foam with porosity cascading in the heat flow direction so that a state closer to uniform temperature distribution can be achieved. A mathematical model that considers natural convection during charging and discharging of the system in addition to non-Darcy effects of the porous foam was developed and validated. The influence of using different cascading arrangements of the metal-foam on the evolution of the solid-liquid interfaces, distribution of isotherms and profile of the liquid fraction was investigated. The use of non-cascaded single-segment foam versus the use of cascaded multi-segment foam was also investigated and compared for the same system’s volume usage. Results from the study show that energy storage and recovery times can be substantially shortened by foam cascading in the PCM/metal foam composite.

Parametric Analysis of PCM Thermal Storage System in an Annual Period

Parametric Analysis of PCM Thermal Storage System in an Annual Period

Simulation analysis of an innovative micro-solar 2kWe Organic Rankine Cycle plant for residential applications

In this paper a 2kWe small scale Organic Rankine Cycle system coupled with a concentrated solar linear Fresnel lens collector is investigated using a simulation analysis. Coupling small scale solar technologies with ORC system is a well-known solution in low temperature ranges. Efforts exist to achieve higher temperatures and overall efficiencies but at present such systems represent a challenge at small scale. This work is part of the EU funded Innova MicroSolar project about development and optimization of a solar linear Fresnel lens concentrator coupled with 2kWe Organic Rankine Cycle plant and with a PCM thermal storage system for residential applications. In this paper a preliminary assessment of the performance of two of the main components of such system (i.e. solar linear Fresnel lens collector and ORC) is presented. A dynamic analysis of the system is performed by varying the operating conditions. In particular the influence of the system configuration and working temperatures on the ORC overall efficiency is evaluated. The final aim of the work indeed is to assess the best working conditions for such micro-CHP to be integrated in residential buildings.

PCM thermal storage design in buildings: Experimental studies and applications to solaria in cold climates

As energy availability and demand often do not match, thermal energy storage plays a crucial role to take advantage of solar radiation in buildings: in particular, latent heat storage via phase-change material is particularly attractive due to its ability to provide high energy storage density. This paper analyzes the performance of a building-integrated thermal storage system to increase the energy performances of solaria in a cold climate. A wall opposing a highly glazed façade (south oriented) is used as thermal storage with phase change materials embedded in the wall. The study is based on both experimental and simulation studies. The concept considered is particularly suited to retrofits in a solarium since the PCM can be added as layers facing the large window on the vertical wall directly opposite.Results indicate that this PCM thermal storage system is effective during the whole year in a cold climate. The thermal storage allows solar radiation to be stored and released up to 6–8 h after solar irradiation: this has effects on both the reduction of daily temperature swings (up to 10°C) and heating requirements (more than 17% on a yearly base). Coupling of the thermal storage system with natural ventilation is important during mid-seasons and summer to improve the PCM charge-discharge cycles and to reduce overheating.Results also show that cooling is less important than heating, reaching up to 20% of the overall annual energy requirements for the city of Montreal, Canada. Moreover, the phase change temperature range of the material used (18–24°C) is below typical summer temperature levels in solaria, but the increase in thermal capacity of the room alone can reduce annual cooling requirements by up to 50%.

Status and development of electric vehicle integrated thermal management from BTM to HVAC

Currently, electric vehicle (EV) are facing unprecedented development opportunities under the support of national policy guidelines and local governments. There is a great potential to substitute EV for internal combustion engine vehicles in the future. However, the practical applications are facing with some essential issues need to be break through, such as battery performance deterioration in some extreme climate areas and driving conditions, heat pump (HP) lower efficiency and defrosting problems under cold temperature region, and vehicle-mounted energy complementation, etc. Therefore, investigations of electric vehicle thermal management (VTM) have gaining increasing attentions in China and other countries.This paper reviewed the status of electric vehicle thermal management worldwide, meanwhile, the basic proposal for further development in the field was presented. From battery thermal management (BTM) to heating ventilation air conditioning (HVAC), a coming work should aim at more research on basic problems, such as exploration of efficient and compact liquid heat exchanger, precise and synergy control of BTM, cold and hot impact phenomena and improving method, mechanism of thermal runaway, ignition and explosion and relative inhibition method, establishment of electric vehicle integrated thermal management system, low energy consumption and frosting inhibition of HP, reutilization of vehicle-mounted energy by PCM thermal storage, and experimental and simulation analysis method system. These explorations will strengthen theoretical and practical understanding and accelerate more extensive application of EV in different regional environment.

Optimization of an encapsulated phase change material thermal energy storage system

Thermal energy storage enables uninterrupted operation of a concentrating solar power (CSP) plant during periods of cloudy or intermittent solar availability. This paper presents a transient computational analysis of an encapsulated phase change material (EPCM) thermal energy storage (TES) system for repeated charging and discharging cycles to investigate its dynamic response. The influence of the design and operating parameters on the dynamic charge and discharge performance of the system is analyzed to identify operating windows that satisfy technoeconomic targets of storage cost less than $15/kWht, round-trip exergetic efficiency greater than 95%, charge time less than 6h and a minimum discharge period of 6h. Overall, this study illustrates a methodology for design and optimization of encapsulated PCM thermal energy storage system (EPCM-TES) for a CSP plant operation.

Experimental investigation and modelling of a low temperature PCM thermal energy exchange and storage system

A real-scale latent heat thermal energy storage (LHTES) device has been designed and set up for air-cooling in the housing sector. This system uses the thermal gap between night-time and daytime outdoor air to refresh the indoor air. The air passes along a box-section horizontal tube bundle filled with paraffin wax (phase change material). To develop a design tool, a one-dimensional model is proposed which describes the thermal behaviour of the LHTES device as the paraffin wax melts. This model takes into account the close-contact exchange between the PCM and the surface of the tubes due to the decreasing density of the PCM as it melts, and the corresponding buoyancy phenomenon. An enthalpy formulation is used for the PCM energy balance equation. An experimental study is performed which validates the modelling approach. This model will be used to simulate the LHTES devices of two single family houses (Napevomo, Sumbiosi). Finally, a first illustrative application of the simulation model of LHTES device is developed by coupling it with a basic mono-zone building performance programme.

Optimising PCM thermal storage systems for maximum energy storage effectiveness

A new performance parameter for PCM thermal storage systems, the energy storage effectiveness, is defined. This parameter can be used to optimise the design of any PCM thermal storage system to maximise the use of the thermal storage media. The paper presents results of a parametric study using an experimentally validated numerical model for PCM encapsulated in plates. The results are used to calculate the energy storage effectiveness which is ultimately used to optimise the useful energy that can be stored in the PCM thermal storage system. The energy storage effectiveness is also used to compare the useable storage capacity of the PCM relative to a sensible energy storage system.

Erratum to: Application of PCM thermal energy storage system to reduce building energy consumption

Erratum to: Application of PCM thermal energy storage system to reduce building energy consumption

Effectiveness–NTU correlation for low temperature PCM encapsulated in spheres

The applicability of the effectiveness–NTU method for characterising a PCM thermal energy storage system was experimentally investigated. The system consisted of PCM encapsulated in spheres with a liquid heat transfer fluid. Freezing and melting tests have been carried out for a variety of conditions on a tank filled with 60 spheres. The investigation demonstrated that a correlation existed between the effectiveness of heat transfer and the mass flow rate in accordance with the effectiveness–NTU relationship for condensers and boilers. It has been proven experimentally that the effectiveness–NTU method is applicable for PCM encapsulated in spheres in a tank.

저 에너지형 축냉식 저온유통 시스템 개발

The purpose of this study is to find the optimal conditions of PCM slurry manufacturing equipment for saving the marketing cost and keeping the original quality of products. In addition, the characteristics of the movable container for shipping or distributing products is analysed. The major results are as follows. 1. PCM thermal storage system is designed with the conditions of temperature(), cold chain time(30 minutes), and one time usage(50 liter). This system includes tank, freezer, circulating pump, cycle type heat exchanger, swelling tank, equipment of supplying PCM supplying unit includes cold tank, cycle type heat exchanger, suction unit and control equipments, etc. 2. After ability test of PCM thermal storage system, it shows that the required freezing time of PCM thermal storage system is less than one of the previous system. The reason is that churn (top and bottom) and compulsion circulation are occurred simultaneously and unit cooler type method is better than chiller type method. 3. By the experiment of transportation latent heat container, it is decided that the best container is with latent heat temperature() and density(0.15%). However, for , it is necessary more studies on latent heat thermal conditions and conditions of making method.

05/02756 Numerical analysis of a PCM thermal storage system with varying wall temperature

05/02756 Numerical analysis of a PCM thermal storage system with varying wall temperature

Numerical analysis of a PCM thermal storage system with varying wall temperature

Numerical analysis of melting and freezing of a PCM thermal storage unit (TSU) with varying wall temperature is presented. The TSU under analysis consists of several layers of thin slabs of a PCM subjected to convective boundary conditions where air flows between the slabs. The model employed takes into account the variations in wall temperature along the direction of air flow as well as the sensible heat. The paper discusses typical characteristics of the melting/freezing of PCM slabs in an air stream and presents some results of the numerical simulation in terms of air outlet temperatures and heat transfer rates during the whole periods of melting and freezing. Considerations in the design of the TSU are also given.