Novel approach to optimize the dimensions of phase change material thermal storage heat exchanger in refrigeration systems

This article reviews the design of solar phase-change energy storage systems and their applications in residential buildings. The solar thermal collection system has high heat collection efficiency, no pollution, and it is also widely used in the field of building heating. In order to improve the efficiency of the solar collector system, the researchers found that integrating phase-change materials (PCMs) into the solar thermal collector system can achieve this goal, but there will be a problem of PCM leakage. Some researchers have solved this problem by microencapsulating PCMs, the thermal conductivity and energy storage efficiency of the PCMs after microencapsulation will be greatly affected. Adjusting the solar collector to an appropriate inclination angle can achieve the highest heat collection efficiency. Choosing the PCM in the appropriate temperature zone can improve the system efficiency. For the separated solar collector system, the parts that need to be considered include the type of heat exchanger, the structure of the energy storage heat exchanger, the shape of the heat exchanger fins, the type of solar collector, and so on. All in all, coupling PCM into the solar collector system can improve energy efficiency reduce carbon emissions and have good economics, the maximum internal rate of return of solar collectors integrated with PCMs in residential and industrial applications is 22% and 17.2%.

Section: Latent Heat Thermal Storage Heat Exchanger Used In Stcmentioning

confidence: 96%

Review on solar collector systems integrated with phase‐change material thermal storage technology and their residential applications

Liu

Zhang

2021

“…Derens-Bertheau 6 presented the results of a cold chain field study in France food preservation. Berdja 18 developed an approach to define the optimal dimensions of a PCM packed bed heat exchanger used as a cold thermal energy storage system in a conventional refrigerator. Metcalf 8 studied the feasibility of applying a low-cost plate heat exchanger solid sorption reactor to solar-powered refrigeration by using a validated reactor model to ice making in developing countries for food preservation.…”

Section: Introductionmentioning

confidence: 99%

“…The abovementioned studies [3][4][5][6][7][8][9][10][11][12][13] revealed that cold storage PCM has not been applied for traditional ice preservation in the aquatic product area of large-medium-sized supermarkets. The aforementioned works [14][15][16][17][18][19][20][21][22][23] used cold storage PCMs, heat storage PCMs, and heat exchangers for cooling, heating, or defrosting. The present study aims to combine cold storage PCM and heat exchanger with ice preservation.…”

Section: Introductionmentioning

confidence: 99%

Performance evaluation of a new ice preservation system for supermarkets

Liu

Lou

et al. 2019

Summary At present, all types of large–medium‐sized supermarkets with aquatic products adopt ice preservation to ensure freshness. The traditional method of ice preservation needs to make a large amount of thick ice and thus wastes manpower and freshwater. A new ice preservation system with cold storage (IP&CS) is designed, and its performance is tested. The use of a cold storage tank to replace the thick ice laid achieves a repeated cold storage and discharge. This experiment uses NaCl solution as the cold storage phase change material (PCM). The phase change temperature of the cold storage PCM and the optimum temperature of the secondary refrigerant during the cold storage process are determined. Results show that the center temperature of aquatic products, water loss rate, color of aquatic products, power consumption, and electricity cost of the IP&CS system are better than those of the traditional ice preservation system.

“…Also, the melting performance was enhanced 15% and 38% with orthogonal and circumferential fin. Berdja et al developed an approach to determine the optimum dimensions of the tank for an encapsulated ITES system. Omara et al reviewed the application of PCMs for increasing the performance of AC systems.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation of thermal performance of geometrically modified spherical ice capsules during the discharging period

Erdemir

2019

Summary Ice thermal energy storage (ITES) is a significant option for shifting cooling load from peak hours to off‐peak hours in order to reduce the cooling cost and equipment capacity. Encapsulated ITES system is one of the most preferred types of ITES systems, because it is easier to apply and has lower initial cost than other types of ITES systems. Capsule geometries have great impact on the thermal performance of the encapsulated ITES system. Spherical capsules are widely used in the application because they provide better thermal performance due to the ratio of its volume to its surface area. Also, modified capsule geometries are used for increasing the thermal performance of the ITES system. This paper focuses on a numerical study in order to determine the effect of the geometrically modified spherical capsule on the thermal performance during the discharging period. Seven geometrically modified spherical capsules were investigated and compared with the ordinary spherical capsule. The FLUENT 17.1 code was used for numerical analyses. At the end of the study, it was found that geometrically modified capsules provided higher thermal performance than an ordinary spherical capsule in the equal capsule volume. Capsule D provided the longest discharging period of 2118 seconds, when VHTF, in = 0.001 m/s and THTF,in = 275.5 K. The lowest discharging time of 464 seconds was obtained with Capsule A, when VHTF, in = 0.01 m/s and THTF, in = 283 K. Among the studied modified capsules, Capsule F performed the worst thermal performance. Energy efficiency values were high, and they did not give comparable difference between the capsule models and working conditions. While all exergy values were 98.50% and higher, exergy efficiency values changed between 85.12% and 51.91%. Exergetically, Capsule D provided the best thermal performance during the discharging period.