Impact Evaluation of Cold Heat Transfer Fluid Temperature on Heat Storage and Mechanical Behaviours of an Energy Storage System Using Phase-Change Material

2021 ◽  
Vol 42 (5) ◽  
Author(s):  
Gang Wang ◽  
Zijian Liu ◽  
Tieliu Jiang ◽  
Zeshao Chen
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Impact Evaluation ◽  
Heat Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Heat Transfer Fluid ◽  
Fluid Temperature ◽  
Mechanical Behaviours ◽  
Change Material

Numerical Investigation of Combined Sensible/Latent Heat Thermal Energy Storage With Supercritical Carbon Dioxide As Heat Transfer Fluid at 650°C

2019 ◽  
Author(s):  
Kelly Osterman ◽  
Diego Guillen ◽  
D. Yogi Goswami
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Energy Storage ◽  
Supercritical Carbon Dioxide ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Storage ◽  
Storage System ◽  
Heat Transfer Fluid ◽  
Dry Air

Abstract This paper numerically explores a high-temperature sensible-latent hybrid thermal energy storage system designed to store heat with output temperatures stabilized at approximately 550–600 °C for direct coupling with supercritical carbon dioxide (sCO2) power cycles operating at their design point. sCO2 and dry air at 25 MPa are used as heat transfer fluid (HTF) in a packed bed storage system that combines rocks as sensible heat storage and AlSi12 as latent heat storage. The base model using dry air at atmospheric pressure is compared to similar work done at ETH Zurich; the model is then extended for use with sCO2 to compare the performance of air and sCO2 at similar volumetric flow rates. It was found that sCO2 is capable of storing a significantly larger amount of energy (∼40 kWh) in the same time period as the air system (∼19 kWh), and can discharge that energy much quicker (1.5 hours compared to 4 hours). However, in order to achieve similar degrees of temperature stabilization, the total height of PCM had to be increased significantly, from 9 cm to 45 cm or more.

scholarly journals PENGGUNAAN PARAFFIN WAX SEBAGAI PENYIMPAN KALOR PADA PEMANAS AIR TENAGA MATAHARI THERMOSYPHON

ROTASI ◽  
2016 ◽  
Vol 18 (3) ◽  
pp. 76 ◽  
Author(s):  
Muhammad Nadjib
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Storage ◽  
Paraffin Wax ◽  
Heat Transfer Fluid ◽  
Sensible Heat ◽  
Latent Heat Storage ◽  
Change Material

Pemanas Air Tenaga Matahari (PATM) konvensional umumnya menggunakan air sebagai penyimpan energi termal. Pemakaian sensible heat storage (SHS) ini memiliki kekurangan, diantaranya adalah densitas energinya rendah. Di sisi lain, latent heat storage (LHS) mempunyai sifat khas yaitu densitas energinya tinggi karena melibatkan perubahan fasa dalam penyerapan atau pelepasan kalor. Material LHS sering disebut phase change material (PCM). Penggunaan PCM pada PATM menarik dilakukan untuk meningkatkan densitas energi sistem. Penelitian ini bertujuan untuk menyelidiki perilaku termal penggunaan paraffin wax di dalam tangki PATM jenis thermosyphon. Penelitian menggunakan kolektor matahari pelat datar dan tangki thermal energy storage (TES) yang dipasang secara horisontal di sisi atas kolektor. Di dalam tangki terdapat alat penukar kalor yang terdiri dari sekumpulan pipa kapsul dimana di dalamnya berisi paraffin wax. Air digunakan sebagai SHS dan heat transfer fluid (HTF). Termokopel dipasang di sisi HTF dan sisi PCM. Piranometer dan sensor temperatur udara luar diletakkan di dekat kolektor matahari. Pengambilan data dilakukan selama proses charging. Temperatur HTF, PCM dan intensitas radiasi matahari direkam setiap 30 detik. Data ini digunakan untuk mengetahui evolusi temperatur HTF dan PCM. Berdasarkan evolusi temperatur ini kemudian dianalisis perilaku termal PATM. Hasil dari penelitian ini adalah bahwa paraffin wax telah berfungsi sebagai penyimpan energi termal bersama air di dalam tangki PATM jenis thermosyphon. PCM memberi kontribusi yang cukup signifikan terhadap kapasitas penyimpanan energi sistem. Efisiensi kolektor lebih optimal karena PCM dapat mempertahankan stratifikasi termal sampai akhir charging. Adanya PCM mampu mengendalikan penurunan efisiensi pengumpulan energi saat intensitas radiasi matahari menurun. Alat penukar kalor yang digunakan cukup efektif yang ditandai dengan kecepatan pemanasan rata-rata antara HTF dan PCM yang tidak berbeda jauh.

Investigation of Using Dispersed Particle and Branching Heat Exchnager in Medium Temperature Thermal Energy Storage System to Achieve Maximum Utilization of Solar Power

2013 ◽  
Author(s):  
A. M. M. G. Hasib ◽  
Rambod Rayegan ◽  
Yong X. Tao
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Power Generation ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Medium Temperature ◽  
Change Material

Maximum utilization of solar energy is very critical to achieve, because a significant portion of solar energy is lost in the form of heat. In that case Thermal Energy Storage (TES) can play a significant role by capturing the energy in the form of heat and later on can be used as a backup source of energy for utilizing it in critical time. On the other side, from the view point of conservation of energy, energy cannot be created or destroyed, but surprisingly a significant amount of energy cannot be utilized due to the instantaneous nature of conventional power generation. So storing Energy is the most unique idea that can act as a strong backup for the instantaneous nature of power generation as it not only adds up to the power generation capacity but also serves to be the most reliable medium of supplying power when the energy demand is at peak. In the authors’ previous work a phase change material (molten solar salt comprised of 60% NaNO3+40%KNO3) and a system design for thermal energy storage (TES) system integrated with a solar Organic Rankine Cycle (ORC) has been proposed. The associated research problems investigated for phase change material (PCM) are the low thermal conductivity and low rate of heat transfer from heat transfer fluid to PCM. In this study a detailed numerical modeling of the proposed design using MATLAB code and the relevant calculation and results are discussed. The numerical model is based on 1-D finite difference explicit technique using the fixed grid enthalpy method. To overcome the research problem highly conductive nano-particle graphite is used to enhance the effective thermal conductivity of the PCM material in theoretical calculation. In the later part of the study results from the numerical computation have been utilized to demonstrate a comparison between a conventional heating system (with a simple single tube as a heat exchanger) and a branching heat exchanger in PCM thermal energy storage system using NTU-Effectiveness method. The comparison results show a significant amount of improvement using branching network and mixing nano-particle in terms of heat transfer, thermal conductivity enhancement, charging time minimization and pressure drop decrease. The results of this study can convince us that the proposed medium temperature TES system coupled with solar ORC can be a stepping-stone for energy efficient and sustainable future in small-scale power generation as the system proves to be better in terms of enhanced heat transfer, increased thermal conductivity and overall sustainability.

scholarly journals Experimental study of solidification of paraffin wax in solar based triple concentric tube thermal energy storage system

2018 ◽  
Vol 22 (2) ◽  
pp. 973-978 ◽  
Author(s):  
Rengarajan Ravi ◽  
Karunakaran Rajasekaran
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Solidification Process ◽  
Energy Storage System ◽  
Paraffin Wax ◽  
Heat Transfer Fluid ◽  
Thermal Energy Storage System

This paper addresses an experimental investigation of a solar based thermal energy storage system to meet current energy demand especially for milk industry in Tamil Nadu, India. A solar based energy storage system has been designed to study the heat transfer characteristics of paraffin wax where it is filled in the middle tube, with cold heat transfer fluid flowing outer tube, inner tube, and both tubes at a time during solidification process in a horizontal triple concentric heat exchanger. In this study, main concentrations are temperature distributions in the energy storage materials such as paraffin wax during solidification process and total solidification time. Three heat recovery methods were used to solidify paraffin wax from the inside tube, outside tube, and both tubes methods to improve the heat transfer between heat transfer fluid and phase change materials. The experiment has been performed for different heat transfer fluid mass-flow rates and different inlet temperatures and predicted results shows that solidification time is reduced.

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