Experimental Study on a New-Type Thermoelectric Heat Pump Phase Change Thermal Energy Storage Device

2011 ◽  
Author(s):  
Min Xu ◽  
Ling Zhang ◽  
ZB Liu ◽  
JL Zhou
Keyword(s):  
Experimental Study ◽  
Energy Storage ◽  
Heat Pump ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Device ◽  
Energy Storage Device ◽  
New Type ◽  
Thermoelectric Heat Pump ◽  
Thermoelectric Heat

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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