Waste Heat Management

2005 ◽  
pp. 115-125
Keyword(s):  
Waste Heat ◽  
Heat Management

Effects of Operating Conditions on the Heat Management of a Microscale Fuel Cell

2019 ◽  
Author(s):  
Liyong Sun ◽  
Adam S. Hollinger ◽  
Jun Zhou
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Waste Heat ◽  
Heat Removal ◽  
Current Collector ◽  
Ambient Air ◽  
Operating Conditions ◽  
Heat Management ◽  
Fuel Flow ◽  
Fuel Stream

Abstract Higher energy densities and the potential for nearly instantaneous recharging make microscale fuel cells very attractive as power sources for portable technology in comparison with standard battery technology. Heat management is very important to the microscale fuel cells because of the generation of waste heat. Waste heat generated in polymer electrolyte membrane fuel cells includes oxygen reduction reaction in the cathode catalyst, hydrogen oxidation reaction in the anode catalyst, and Ohmic heating in the membrane. A novel microscale fuel cell design is presented here that utilizes a half-membrane electrode assembly. An ANSYS Fluent model is presented to investigate the effects of operating conditions on the heat management of this microscale fuel cell. Five inlet fuel temperatures are 22°C, 40°C, 50°C, 60°C, and 70°C. Two fuel flow rate are 0.3 mL/min and 2 mL/min. The fuel cell is simulated under natural convection and forced convection. The simulations predict thermal profiles throughout this microscale fuel cell design. The exit temperature of fuel stream, oxygen stream and nitrogen stream are obtained to determine the rate of heat removal. Simulation results show that the fuel stream dominates heat removal at room temperature. As inlet fuel temperature increases, the majority of heat removal occurs via convection with the ambient air by the exposed current collector surfaces. The top and bottom current collector removes almost the same amount of heat. The model also shows that the heat transfer through the oxygen channel and nitrogen channel is minimal over the range of inlet fuel temperatures. Increasing fuel flow rate and ambient air flow both increase the heat removal by the exposed current collector surfaces. Ultimately, these simulations can be used to determine design points for best performance and durability in a single-channel microscale fuel cell.

Urban Heat Management in Louisville, Kentucky: A Framework for Climate Adaptation Planning

2019 ◽  
pp. 0739456X1987921 ◽  
Author(s):  
Brian Stone ◽  
Kevin Lanza ◽  
Evan Mallen ◽  
Jason Vargo ◽  
Armistead Russell
Keyword(s):  
Green Infrastructure ◽  
Climate Adaptation ◽  
Waste Heat ◽  
Management Strategies ◽  
Tree Planting ◽  
Heat Management ◽  
Management Plans ◽  
Urban Heat ◽  
The Impact ◽  
Related Mortality

We explore the potential for cities to develop urban heat management plans to moderate rising temperatures and to lessen the impact of extreme heat on human health. Specifically, we model the impacts of heat management strategies, including tree planting and other green infrastructure, cool roofing and paving, and a reduction in waste heat emissions from buildings and vehicles, on estimated heat-related mortality across Louisville, Kentucky. Our assessment finds a combination of urban heat management strategies to lessen summer temperatures by as much as 10°F on hot days and to reduce estimated heat-related mortality by more than 20 percent.

Gravity-Assisted Heat Pipe With Strong Marangoni Fluid for Waste Heat Management of Single and Dual-Junction Solar Cells

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Kenneth M. Armijo ◽  
Van P. Carey
Keyword(s):  
Heat Flux ◽  
Solar Cells ◽  
Heat Pipe ◽  
Waste Heat ◽  
Working Fluid ◽  
Water Mixture ◽  
Heat Management ◽  
Strong Concentration ◽  
Electrical Efficiency ◽  
Pipe System

This study investigates the cooling of single and multijunction solar cells with an inclined, gravity-assisted heat pipe, containing a 0.05 M 2-propanol/water mixture that exhibits strong concentration Marangoni effects. Heat pipe solar collector system thermal behavior was investigated theoretically and semi-empirically through experimentation of varying input heat loads from attached strip-heaters to simulate waste heat generation of single-junction monocrystalline silicon (Si), and dual-junction GaInP/GaAs photovoltaic (PV) solar cells. Several liquid charge ratios were investigated to determine an optimal working fluid volume that reduces the evaporator superheat while enhancing the vaporization transport heat flux. Results showed that a 45% liquid charge, with a critical heat flux of 114.8 W/cm2, was capable of achieving the lowest superheat levels, with a system inclination of 37 deg. Solar cell semiconductor theory was used to evaluate the effects of increasing temperature and solar concentration on cell performance. Results showed that a combined PV/heat pipe system had a 1.7% higher electrical efficiency, with a concentration ratio 132 suns higher than the stand-alone system. The dual-junction system also exhibited enhanced performance at elevated system temperatures with a 2.1% greater electrical efficiency, at an operational concentration level 560 suns higher than a stand-alone system.

Nanophotonic-Engineered Photothermal Harnessing for Waste Heat Management and Pyroelectric Generation

ACS Nano ◽  
2017 ◽  
Vol 11 (10) ◽  
pp. 10568-10574 ◽  
Author(s):  
Xiao-Qiao Wang ◽  
Chuan Fu Tan ◽  
Kwok Hoe Chan ◽  
Kaichen Xu ◽  
Minghui Hong ◽  
...  
Keyword(s):  
Waste Heat ◽  
Heat Management

Waste Heat Management System for Hybrid Vehicles Using Thermoelectric Generator

2020 ◽  
Vol 12 (8) ◽  
pp. 1063-1066
Author(s):  
R. Asteekar ◽  
S. Senthamil Selvan ◽  
R. Janani
Keyword(s):  
Waste Heat ◽  
Electrical Energy ◽  
Hybrid Vehicles ◽  
Heat Management ◽  
Storage Unit ◽  
Thermo Electric ◽  
Electric Generator ◽  
Sustainable Resources ◽  
Load Demand ◽  
Future Potential

The present scenario is like that the need of the electrical energy is growing rapidly whereas the resource availability is lagging behind the load demand due to its extinction which leads to hinder our overall generation. It has been observed that the sustainable resources have great future potential to take lead to generate power and supply demand. In the present scenario there exists a few energy resources equivalent to fuel resource. So, there must be a technology to trap the waste and unutilized heat available in the atmosphere and utilize it into the form useful electrical energy. In the current situation, waste heat in the form of thermal energy is recovered and converted into conventional electrical energy. Today, 70% of produced energy in automobiles is wasted in form of heat by exhaust gases. The main outcome of this paper is to manage the waste heat is being generated in the vehicles efficiently, by introducing the concept of “Thermo Electric Generator” (TEG) which convert the waste heat produced inside the vehicles and Re-Generate in the form electric current and give it back to the “storage unit” due to “Seebeck effect” concept.

Feasibility Study on Waste Heat Management for Space Solar Power System

2003 ◽  
Vol 2003 (0) ◽  
pp. 89-90 ◽  
Author(s):  
Haruhiko OHTA ◽  
Haruo KAWASAKI ◽  
Shinichi TOYAMA ◽  
Toshiyuki OHNO
Keyword(s):  
Power System ◽  
Feasibility Study ◽  
Solar Power ◽  
Waste Heat ◽  
Heat Management ◽  
Space Solar Power

scholarly journals Performance Assessment of Low-Temperature Thermal Storage with Electromagnetic Control

2014 ◽  
Vol 6 ◽  
pp. 735042
Author(s):  
Ya-Wei Lee
Keyword(s):  
Low Temperature ◽  
Waste Heat ◽  
Thermal Storage ◽  
Heat Management ◽  
Local Flow ◽  
Flow Fluctuations ◽  
Perturbation Mode ◽  
Energy Consuming ◽  
Energy Transportation ◽  
Operational Range

This study presents electromagnetic-controlled thermal storage (ECTS) that can be directly implemented in strategies of low-temperature waste heat recovery for energy-consuming equipment. A magnetic nanofluid (MNF) prepared from fine iron ferrite ferromagnetic particles is recommended as a latent heat medium (LHM). During electromagnetic induction, local flow fluctuations are generated and thermal convection in the MNF can be enhanced. The achieved results demonstrated that ECTS has a wide operational range and an optimum storage efficiency of 84.46%. Thus, a self-perturbation mode used to enhance thermal energy transportation can be designed for numerous waste heat management applications.

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