Design of Subsystem for Mobile Auxiliary Power Unit Based on PEM Fuel Cells Stack

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F18%3A43916140" target="_blank" >RIV/60461373:22310/18:43916140 - isvavai.cz</a>

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RIV/60461373:22310/18:43916141

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Design of Subsystem for Mobile Auxiliary Power Unit Based on PEM Fuel Cells Stack

Popis výsledku v původním jazyce

PEM fuel cells represents a promising device for efficient conversion of chemical energy carried by fuel into electrical energy. Absence of moving parts is the main reason for quiet operation of fuel cells. Water is a product of reaction of hydrogen with oxygen without any dangerous pollutants. Mentioned properties make mobile fuel cell stacks suitable as a power source for mobile medical beds, medical beds in field hospitals or source of energy for lighting and charging of communication devices in evacuation centers. Other potential applications are power source for rescues or reserve power sources for firemans and medicals or speleology. All these applications require power output in a range of 80-200 W for long time and up-to 500 W for short-time operation. Therefore this project is focused to design of mobile auxiliary power unit based on PEM fue cell at this power output. Electric power consumption of connected electronic devices is vary in time. Target of balancing is to minimization variation in APU voltage with changing loads. Balancing can be accomplished by utilizing correspondingly sized accumulators or supercapacitors connected to the fuel cell stack. Most effective solution is using combination of accumulators and supercapacitors for balancing of stack. High weight and dimensions and complicated driving system are disadvantages of this solution. Using of accumulator with high internal capacity is more effective and snappy. One of the most important parameter of whole system is weight, because system has to be mobile. Safety load in the outdoor terrain is up to 15 kg. It is reason, why weight of whole system has to be lower than this limit. Weight without gas cylinder is considered, because gas can be moved separately. Housing have to protect fuel cell before damage by falling. Humidifier and all devices for fuel supply, air supply and energy balancing must fit in together with fuel cell stack. Air is used as a prefered oxidant, because it is not necessary to use reduction valve, gas flow controller and oxygen gas cylinder. Main problem of ambient air represents its purity. Especially in the industrial agglomerations content of various impurities in air can potentially reach high level. Some compounds like dihydrogen sulphide, carbon monoxide and selected organic compounds can poison platinum catalysts. Mechanical compounds can block gas diffusion electrode and impair transport of oxygen and water in electrode. Therefore it is necessary to include air purification in to the system. Selected filter have to operate with low pressure drop, because increased pressure drop leads to increasing energy demands of the system. System have to include some sensor. One group of sensors have to monitor content of impurities in ambient air and state of filters. Second group of sensors, monitor concentration of hydrogen in housing and at output air from fuel cell. Leakages of armatures or fuel cell can by detected by presence of hydrogen in housing. Fuel cell make exhaust of hydrogen in some interval. This hydrogen is feeded into output of air from fuel cell, and his concentration cannot reach flammable or explosive level. Sensors based on catalytic burning represents robust technology, which is nonselective with high energy demand. Electrochemical sensors are selective with low consumption but with low range and high sensitivity to high concentrations of followed compound.

Název v anglickém jazyce

Design of Subsystem for Mobile Auxiliary Power Unit Based on PEM Fuel Cells Stack

Popis výsledku anglicky

PEM fuel cells represents a promising device for efficient conversion of chemical energy carried by fuel into electrical energy. Absence of moving parts is the main reason for quiet operation of fuel cells. Water is a product of reaction of hydrogen with oxygen without any dangerous pollutants. Mentioned properties make mobile fuel cell stacks suitable as a power source for mobile medical beds, medical beds in field hospitals or source of energy for lighting and charging of communication devices in evacuation centers. Other potential applications are power source for rescues or reserve power sources for firemans and medicals or speleology. All these applications require power output in a range of 80-200 W for long time and up-to 500 W for short-time operation. Therefore this project is focused to design of mobile auxiliary power unit based on PEM fue cell at this power output. Electric power consumption of connected electronic devices is vary in time. Target of balancing is to minimization variation in APU voltage with changing loads. Balancing can be accomplished by utilizing correspondingly sized accumulators or supercapacitors connected to the fuel cell stack. Most effective solution is using combination of accumulators and supercapacitors for balancing of stack. High weight and dimensions and complicated driving system are disadvantages of this solution. Using of accumulator with high internal capacity is more effective and snappy. One of the most important parameter of whole system is weight, because system has to be mobile. Safety load in the outdoor terrain is up to 15 kg. It is reason, why weight of whole system has to be lower than this limit. Weight without gas cylinder is considered, because gas can be moved separately. Housing have to protect fuel cell before damage by falling. Humidifier and all devices for fuel supply, air supply and energy balancing must fit in together with fuel cell stack. Air is used as a prefered oxidant, because it is not necessary to use reduction valve, gas flow controller and oxygen gas cylinder. Main problem of ambient air represents its purity. Especially in the industrial agglomerations content of various impurities in air can potentially reach high level. Some compounds like dihydrogen sulphide, carbon monoxide and selected organic compounds can poison platinum catalysts. Mechanical compounds can block gas diffusion electrode and impair transport of oxygen and water in electrode. Therefore it is necessary to include air purification in to the system. Selected filter have to operate with low pressure drop, because increased pressure drop leads to increasing energy demands of the system. System have to include some sensor. One group of sensors have to monitor content of impurities in ambient air and state of filters. Second group of sensors, monitor concentration of hydrogen in housing and at output air from fuel cell. Leakages of armatures or fuel cell can by detected by presence of hydrogen in housing. Fuel cell make exhaust of hydrogen in some interval. This hydrogen is feeded into output of air from fuel cell, and his concentration cannot reach flammable or explosive level. Sensors based on catalytic burning represents robust technology, which is nonselective with high energy demand. Electrochemical sensors are selective with low consumption but with low range and high sensitivity to high concentrations of followed compound.

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

10405 - Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

Projekt

<a href="/cs/project/VI20152019018" target="_blank" >VI20152019018: Vývoj a realizace nezávislého DC zdroje napájení s vodíkovým palivovým článkem</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů