Investigation of Temperature Limitations During Rapid Thermal Cycling of a Micro-Tubular Flame-Assisted Fuel Cell

2021 ◽  
Author(s):  
Ryan Milcarek ◽  
Rhushikesh Ghotkar ◽  
Jeongmin Ahn
Keyword(s):  
Fuel Cell ◽  
Thermal Cycling ◽  
Rapid Thermal Cycling

Investigation of Temperature Limitations During Rapid Thermal Cycling of a Micro-Tubular Flame-Assisted Fuel Cell

2020 ◽  
Author(s):  
Ryan J. Milcarek ◽  
Rhushikesh Ghotkar ◽  
Jeongmin Ahn
Keyword(s):  
Fuel Cell ◽  
Thermal Cycling ◽  
Power Density ◽  
Thermal Insulation ◽  
Current Collector ◽  
Operating Conditions ◽  
Slow Heating ◽  
Maximum Temperature ◽  
Sofc Cathode ◽  
Rapid Thermal Cycling

Abstract Despite many efforts and improvements over the last few decades, two of the major challenges facing Solid Oxide Fuel Cells (SOFCs) are slow heating rates to operating conditions (typically < 5 °C.min−1) and a limited ability to thermal cycle (< 200 cycles). Recently a novel hybridized setup that combines a fuel-rich combustion reformer with a SOFC was developed and utilized to investigate rapid heating, cooling and thermal cycling of a micro-Tubular SOFC. The setup places the SOFC directly in the flame and exhaust of the high temperature combustion of methane, which allows for extremely rapid temperature rise in the SOFC. A SOFC with a (La0.8Sr0.2)0.95MnO3-x cathode was tested in the setup, but limitations on air preheating for the cathode resulted in low SOFC cathode temperatures (∼500°C) and low power density. Thermal insulation improved pre-heating of the air delivered to the cathode, increased the SOFC cathode temperature and, when a (La0.60Sr0.40)0.95Co0.20Fe0.80O3-x cathode was applied to the SOFC, resulted in improved power density. After adjusting the thermal insulation, the air temperature near the cathode exceeded ∼750°C during testing. Over 3,000 thermal cycles were conducted at a heating rate exceeding 900°C.min−1 and a cooling rate that exceeded 300°C.min−1. The open circuit voltage was analyzed over the 150 h test and a low degradation rate of ∼0.0008V per 100 cycles per fuel cell was observed. Unlike the previous test, which was conducted at lower temperatures, significant degradation of the current collector was observed during this test. Electrochemical impedance spectroscopy shows that degradation in the SOFC was due to increases in ohmic losses, activation losses at the cathode and increased concentration losses. The setup demonstrates that rapid thermal cycling of micro-Tubular SOFCs can be achieved, but there are limitations on the maximum temperature that can be sustained depending on the current collector.

Metal-supported solid oxide fuel cell membranes for rapid thermal cycling

2005 ◽  
Vol 176 (5-6) ◽  
pp. 443-449 ◽  
Author(s):  
Y MATUS ◽  
L DEJONGHE ◽  
C JACOBSON ◽  
S VISCO
Keyword(s):  
Fuel Cell ◽  
Thermal Cycling ◽  
Solid Oxide Fuel Cell ◽  
Cell Membranes ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Cell Membranes ◽  
Rapid Thermal Cycling

Thermal shock resistance of Ti3SiC2 ceramic under extremely rapid thermal cycling

2021 ◽  
Vol 866 ◽  
pp. 158985
Author(s):  
Xiaojia Su ◽  
Yiwang Bao ◽  
Detian Wan ◽  
Haibin Zhang ◽  
Ludi Xu ◽  
...  
Keyword(s):  
Thermal Cycling ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Shock Resistance ◽  
Rapid Thermal Cycling

Analysis of Long-Term and Thermal Cycling Tests for a Commercial Solid Oxide Fuel Cell

2017 ◽  
Vol 14 (4) ◽  
Author(s):  
Dustin Lee ◽  
Jing-Kai Lin ◽  
Chun-Huang Tsai ◽  
Szu-Han Wu ◽  
Yung-Neng Cheng ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Thermal Cycling ◽  
Solid Oxide Fuel Cell ◽  
Coefficient Of Thermal Expansion ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Flow Rates ◽  
Degradation Rates ◽  
Two Stages

The effects of isothermally long-term and thermal cycling tests on the performance of an ASC type commercial solid oxide fuel cell (SOFC) have been investigated. For the long-term test, the cells were tested over 5000 h in two stages, the first 3000 h and the followed 2000 h, under the different flow rates of hydrogen and air. Regarding the thermal cycling test, 60 cycles in total were also divided into two sections, the temperature ranges of 700 °C to 250 °C and 700 °C to 50 °C were applied for the every single cycle of first 30 cycles and the later 30 cycles, respectively. The results of long-term test show that the average degradation rates for the cell in the first 3000 h and the followed 2000 h under different flow rates of fuel and air are 1.16 and 2.64%/kh, respectively. However, there is only a degradation of 6.6% in voltage for the cell after 60 thermal cycling tests. In addition, it is found that many pores formed in the anode of the cell which caused by the agglomeration of Ni after long-term test. In contrast, the vertical cracks penetrating through the cathode of the cell and the in-plane cracks between the cathode and barrier layer of the cell formed due to the coefficient of thermal expansion (CTE) mismatch after 60 thermal cycling tests.

A Simulation of the Solid Oxide Fuel Cell Electrochemical Light Off Phenomenon

2005 ◽  
Author(s):  
Comas L. Haynes ◽  
J. Chris Ford
Keyword(s):  
Fuel Cell ◽  
Thermal Cycling ◽  
Solid Oxide Fuel Cell ◽  
Heat Generation ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Cell Potential ◽  
Start Up ◽  
Electrochemical Transport

During latter-stage, “start-up” heating of a solid oxide fuel cell (SOFC) stack to a desired operating temperature, heat may be generated in an accelerating manner during the establishment of electrochemical reactions. This is because a temperature rise in the stack causes an acceleration of electrochemical transport given the typical Arrhenius nature of the electrolyte conductivity. Considering a potentiostatic condition (i.e., prescribed cell potential), symbiosis thus occurs because greater current prevalently leads to greater by-product heat generation, and vice versa. This interplay of the increasing heat generation and electrochemistry is termed “light off”, and an initial model has been developed to characterize this important thermal cycling phenomenon. The results of the simulation begin elucidating the prospect of using cell potential as well as other electrochemical operating conditions (e.g., reactants utilization) as dynamic controls in managing light off transients and possibly mitigating thermal cycling issues.

Two-Station Embossing Process for Rapid Fabrication of Polymer Microstructures

2005 ◽  
Author(s):  
Donggang Yao ◽  
Allen Y. Yi ◽  
Lei Li ◽  
Pratapkumar Nagarajan
Keyword(s):  
Thermal Cycling ◽  
Elevated Temperatures ◽  
Polymeric Materials ◽  
Large Mass ◽  
Hot Embossing ◽  
Electrical Heating ◽  
Thermal Mass ◽  
Mold Surface ◽  
Cycle Times ◽  
Rapid Thermal Cycling

The hot embossing technique is becoming an increasingly important alternative to silicon-and glass-based microfabrication technologies. The advantage of hot embossing can be mainly attributed to the versatile properties and mass production capability of polymeric materials. However, because of the use of a large mass in thermal cycling, hot embossing is subject to substantially longer cycle times than those in traditional thermoplastic molding processes.1 The longer dwell time at elevated temperatures could further result in degradation of the embossing polymer, especially for thermally sensitive polymers. The problem exacerbates when thick polymer substrates are used. To address this problem, rapid thermal cycling of the tool is needed. One method for rapid thermal cycling is to employ a low-thermal-mass multilayer mold with electrical heating elements installed right beneath the mold surface.2 This method, however, is complex in nature and may be prone to problems caused by mismatching of thermal and mechanical properties between different layers.

Carbide-bonded graphene coated zirconia for achieving rapid thermal cycling under low input voltage and power

2019 ◽  
Vol 45 (18) ◽  
pp. 24318-24323
Author(s):  
Min Wu ◽  
Lin Zhang ◽  
Eusebio Duarte Cabrera ◽  
Jun-Jie Pan ◽  
Hao Yang ◽  
...  
Keyword(s):  
Thermal Cycling ◽  
Input Voltage ◽  
Low Input ◽  
Rapid Thermal Cycling
Sign in / Sign up

Export Citation Format

Share Document