Thermo-electrochemical cells based on polymer and mineral hydrogels for low-grade waste heat conversion

Author(s):  
Alexandr Shindrov ◽  
Denis Artyukhov ◽  
Maria Vikulova ◽  
Nikolay Spirin ◽  
Natalya Nikitina ◽  
...  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Isuru E. Gunathilaka ◽  
Jennifer M. Pringle ◽  
Luke A. O’Dell

AbstractLow-grade waste heat is an abundant and underutilised energy source. In this context, thermo-electrochemical cells (i.e., systems able to harvest heat to generate electricity) are being intensively studied to deliver the promises of efficient and cost-effective energy harvesting and electricity generation. However, despite the advances in performance disclosed in recent years, understanding the internal processes occurring within these devices is challenging. In order to shed light on these mechanisms, here we report an operando magnetic resonance imaging approach that can provide quantitative spatial maps of the electrolyte temperature and redox ion concentrations in functioning thermo-electrochemical cells. Time-resolved images are obtained from liquid and gel electrolytes, allowing the observation of the effects of redox reactions and competing mass transfer processes such as thermophoresis and diffusion. We also correlate the physicochemical properties of the system with the device performance via simultaneous electrochemical measurements.


2021 ◽  
Author(s):  
Luke O'Dell ◽  
Isuru Gunathilaka ◽  
Jennifer Pringle ◽  
Maria Forsyth

Abstract Low-grade waste heat is an abundant and underutilised energy source, and the promise of thermo-electrochemical cells to harvest this resource and power applications such as wearable devices and sensors is increasingly being realised. However, despite substantial advances in performance in recent years, understanding the interior processes occurring within these devices remains a challenge. Here we report an operando magnetic resonance imaging (MRI) approach that can provide quantitative spatial maps of electrolyte temperature and redox ion concentrations in functioning thermo-electrochemical cells. Time-resolved images are obtained from liquid and gel electrolytes, allowing the effects of redox reactions and competing mass transfer effects such as thermophoresis and diffusion to be visualised and correlated with the device performance via simultaneous electrochemical measurements. This method offers valuable insights into these devices and will greatly aid their future design and optimisation.


1992 ◽  
Vol 25 (12) ◽  
pp. 33-47 ◽  
Author(s):  
T. S. C. Gross ◽  
R. R. Cohen

The small island of Jersey is served by a single wastewater treatment plant at Bellozanne. Since its inception some 30 years ago the sludge produced has been used on agricultural land. Inevitably there are circumstances which prevent this happening without interruption, eg, poor weather, or seasonal demand. On these occasions, the island has no other disposal option to fall back on. Furthermore, concerns over the practice have created a perception that it might be doing harm to the ‘quality' of the farm produce. The responsible body, the Public Services Department, formulated a flexible, multiple option solution and commissioned Halcrow to engineer the capital works. The works centre around a thermal drying plant using biogas produced by the digestion process as the main fuel. Waste heat is recovered for digester heating making the total process potentially self sufficient in energy. At the same time, the bulk of the product is reduced considerably, providing an easily transported material with potential for use directly on the land as a fertilizer substitute or as a low grade fuel. Farfrom being a disposal problem requiring manpower and expense, sludge will soon be regarded by the States of Jersey as a valuable resource with a revenue potential.


APL Materials ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 011105
Author(s):  
Daniel Dzekan ◽  
Anja Waske ◽  
Kornelius Nielsch ◽  
Sebastian Fähler
Keyword(s):  

Author(s):  
Noman Yousuf ◽  
Timothy Anderson ◽  
Roy Nates

Abstract Despite being identified nearly a century ago, the diffusion absorption refrigeration (DAR) cycle has received relatively little attention. One of the strongest attractions of the DAR cycle lies in the fact that it is thermally driven and does not require high value work. This makes it a prime candidate for harnessing low grade heat from solar collectors, or the waste heat from stationary generators, to produce cooling. However, to realize the benefits of the DAR cycle, there is a need to develop an improved understanding of how design parameters influence its performance. In this vein, this work developed a new parametric model that can be used to examine the performance of the DAR cycle for a range of operating conditions. The results showed that the cycle's performance was particularly sensitive to several factors: the rate of heat added and the temperature of the generator, the effectiveness of the gas and solution heat exchangers, the mass flowrate of the refrigerant and the type of the working fluid. It was shown that can deliver good performance at low generator temperatures if the refrigerant mass fraction in the strong solution is made as high as possible. Moreover, it was shown that a H2O-LiBr working pair could be useful for achieving cooling at low generator temperatures.


Author(s):  
James F. Walton ◽  
Andrew Hunsberger ◽  
Hooshang Heshmat

In this paper the authors will present the design and preliminary test results for a distributed electric generating system that uses renewable energy source for economical load-following and peak-shaving capability in an oil-free, high-speed micro-turboalternator system using compliant foil bearings and a permanent magnet alternator. Test results achieved with the prototype system operating to full speed and under power generating mode will be presented. A comparison between predicted and measured electrical output will also be presented up to a power generating level of 25 kWe at approximately 55,000 rpm. The excellent correlation between design and test provides the basis for scale up to larger power levels. Based upon the turboalternator test results a thermodynamic cycle analysis of a system using low grade waste heat water at approximately 100 C will be reviewed. The tradeoff study results for a series of environmentally friendly refrigerant working fluids will also be presented including sensitivity to vaporization and condensing temperatures. Based on the cycle and pinch point analyses predicted maximum output power was determined. Finally a preliminary turbine design for the selected R134a working fluid was completed. The results of this study show that a net output power level of greater than 40 kW is possible for approximately 240 l/m flow of water at 100C is possible.


Sign in / Sign up

Export Citation Format

Share Document