A Hybrid Thermal Energy Storage Device, Part 1: Design Methodology

2004 ◽  
Vol 126 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Ning Zheng ◽  
R. A. Wirtz
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Sink ◽  
Thermal Response ◽  
Performance Model ◽  
Storage Device ◽  
Loading Constraints ◽  
Model Predictions

A thermal response model for designing a hybrid thermal energy storage (TES) heat sink is developed. The stabilization time and maximum operating (hot side) temperature-to-transition temperature difference are used to characterize the performance of the heat sink. The thermal properties of the PCM employed in the design are investigated. Integration of a design optimization algorithm into a thermal performance model of the TES-hybrid heat sink results in determination of a best design subject to geometric and heat loading constraints. A prototype based on this best design is build and used to benchmark the performance model. The performance measured is consistent with the simulation model predictions of performance.

Methodology for Designing a Hybrid Thermal Energy Storage Heat Sink

2000 ◽  
Author(s):  
Ning Zheng ◽  
R. A. Wirtz
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Sink ◽  
Thermal Response ◽  
Performance Model ◽  
Loading Constraints ◽  
Model Predictions ◽  
Heat Loading

Abstract A thermal response model for designing a hybrid thermal energy storage (TES) heat sink is developed. The stabilization time and maximum operating (hot side) temperature-to-transition temperature difference are used to characterize the performance of the heat sink. The thermal properties of the PCM employed in the design are investigated. Integration of a design optimization algorithm into a thermal performance model of the TES-hybrid heat sink results in determination of a best design subject to geometric and heat loading constraints. A prototype based on this best design is build and used to benchmark the performance model. The performance measured is consistent with the simulation model predictions of performance.

scholarly journals Multidisciplinary Approaches for Assessing a High Temperature Borehole Thermal Energy Storage Facility at Linköping, Sweden

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4379
Author(s):  
Max Hesselbrandt ◽  
Mikael Erlström ◽  
Daniel Sopher ◽  
Jose Acuna
Keyword(s):  
Thermal Properties ◽  
High Temperature ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Thermal Response ◽  
Site Investigation ◽  
Thermal Response Test ◽  
Response Test ◽  
Crystalline Bedrock

Assessing the optimal placement and design of a large-scale high temperature energy storage system in crystalline bedrock is a challenging task. This study applies and evaluates various methods and strategies for pre-site investigation for a potential high temperature borehole thermal energy storage (HT-BTES) system at Linköping in Sweden. The storage is required to shift approximately 70 GWh of excess heat generated from a waste incineration plant during the summer to the winter season. Ideally, the site for the HT-BTES system should be able to accommodate up to 1400 wells to 300 m depth. The presence of major fracture zones, high groundwater flow, anisotropic thermal properties, and thick Quaternary overburden are all factors that play an important role in the performance of an HT-BTES system. Inadequate input data to the modeling and design increases the risk of unsatisfactory performance, unwanted thermal impact on the surroundings, and suboptimal placement of the HT-BTES system, especially in a complex crystalline bedrock setting. Hence, it is crucial that the subsurface geological conditions and associated thermal properties are suitably characterized as part of pre-investigation work. In this study, we utilize a range of methods for pre-site investigation in the greater Distorp area, in the vicinity of Linköping. Ground geophysical methods, including magnetic and Very Low-Frequency (VLF) measurements, are collected across the study area together with outcrop observations and lab analysis on rock samples. Borehole investigations are conducted, including Thermal Response Test (TRT) and Distributed Thermal Response Test (DTRT) measurements, as well as geophysical wireline logging. Drone-based photogrammetry is also applied to characterize the fracture distribution and orientation in outcrops. In the case of the Distorp site, these methods have proven to give useful information to optimize the placement of the HT-BTES system and to inform design and modeling work. Furthermore, many of the methods applied in the study have proven to require only a fraction of the resources required to drill a single well, and hence, can be considered relatively efficient.

Thermal Energy Storage Thermal Response Model With Application to Thermal Management of High Power-Density Hand-Held Electronics

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
R. A. Wirtz ◽  
K. Swanson ◽  
M. Yaquinto
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
High Power ◽  
Thermal Energy Storage ◽  
Heat Storage ◽  
Thermal Response ◽  
High Power Density ◽  
Storage Volume ◽  
Change Material

An important design objective that is unique to hand-held units is the need to constrain two temperatures: the maximum temperature of the electronic components and the maximum skin temperature of the hand-held unit. The present work identifies and evaluates, through parametric modeling and experiments, the passive thermal energy storage volume characteristics and phase change material composite properties that are most suitable for thermal control of small form-factor, high power-density, hand-held electronics. A one-dimensional transient analytical model, based on an integral heat balance, is formulated and benchmarked. The model accurately simulates the heat storage/recovery process in a semi-infinite, “dry” phase change material slab. Dimensional analysis identifies the time and temperature metrics and nondimensional parameters that describe the heat storage/release process. Parametric analysis illustrates how changes in these nondimensional parameters affect thermal energy storage volume thermal response.

Numerical Analysis on Thermal Energy Storage Device With Finned Copper Tube for an Indirect Type Solar Drying System

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Satyapal Yadav ◽  
V. P. Chandramohan
Keyword(s):  
Energy Storage ◽  
Numerical Analysis ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Air Flow ◽  
Storage Device ◽  
Energy Storage Device ◽  
Solar Drying ◽  
Solar Dryer ◽  
Air Flow Velocity

Solar dryer with thermal energy storage device is an essential topic for food drying applications in industries. In this work, a two-dimensional (2D) numerical model is developed for the application of solar drying of agricultural products in an indirect type solar dryer. The phase-change material (PCM) used in this work is paraffin wax. The study has been performed on a single set of concentric tube which consists of a finned inner copper tube for air flow and an outer plastic tube for PCM material. The practical domain is modeled using ANSYS, and computer simulations were performed using ANSYS fluent 2015. The air velocity and temperature chosen for this study are based on the observation of indirect type solar dryer experimental setup. From this numerical analysis, the temperature distribution, melting, and solidification fraction of PCM are estimated at different air flow velocities, time, and inlet temperature of air. It is concluded that the drying operation can be performed up to 10.00 p.m. as the PCM transfers heat to inlet air up to 10.00 p.m. and before it got charged up to 3.00 p.m. because of solar radiation. The maximum outlet temperature is 341.62 K (68.62 °C) which is suitable for food drying applications. Higher air flow velocity enhances quick melting of PCM during charging time and quick cooling during recharging of inlet air; therefore, higher air flow velocity is not preferred for food drying during cooling of PCM.

Numerical analysis on thermal energy storage device to improve the drying time of indirect type solar dryer

2018 ◽  
Vol 54 (12) ◽  
pp. 3631-3646 ◽  
Author(s):  
Satyapal Yadav ◽  
Abhay Bhanudas Lingayat ◽  
V.P. Chandramohan ◽  
V. R. K. Raju
Keyword(s):  
Energy Storage ◽  
Numerical Analysis ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Device ◽  
Energy Storage Device ◽  
Drying Time ◽  
Solar Dryer

Exploration of Variable Conductance Effects During Input and Extraction of Heat From Phase Change Thermal Storage

2018 ◽  
Author(s):  
Zachary M. Theroff ◽  
Dre Helmns ◽  
Van P. Carey
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Thermal Conductance ◽  
Working Fluid ◽  
Storage Device ◽  
Energy Storage Device ◽  
Storage Unit ◽  
Average Value

Previous efforts to model the effectiveness of heat input and extraction from a thermal storage unit have generally been based on the definition of a constant conductance of heat from the working fluid to the phase change storage material. In order to capture the effects of changing thermal resistance between the working fluid and melt front location, this paper presents a method using a resistor network analogy to account for thermal conductance as a function of melt fraction. This expression for thermal conductance is then implemented in an existing numerical framework. Results are validated by comparing calculations for a single unit cell using a quasi-steady Stefan problem approach, a finite difference scheme, and more general form solutions from literature. The variable approach is then compared with an average value for overall thermal conductivity, U, to characterize the performance of a thermal energy storage unit consisting of a series of these unit cells. Overall effectiveness in the thermal energy storage device is found to be within 0.6% agreement when comparing these methods, though local percent deviation can be as high as 113%. Depending on the needed accuracy and use case for such a numerical framework, suggestions are provided on whether an average value for U is sufficient for characterizing such a thermal energy storage device. Discussion is also provided on the flexibility of the computation schemes described by testing the sensitivity of the results via changes in dimension-less input parameters.

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