Chaotizovaný svazek polymerních dutých vláken v křížovém uspořádání v aplikaci vzduch-voda

Chaotised polymeric hollow fiber bundle as a crossflow heat exchanger in air-water application

abstract

en

Polymeric hollow fibre heat exchangers are an alternative to common metal heat exchangers in low temperature applications. Their advantages are low cost, low weight and corrosion resistance. The heat transfer surface consists of hundreds or even thousands of fibres of small diameter. In order to provide direct contact of fibres with the surrounding stream of fluid there is need to separate fibres from each other to let fluid flow between. There is simple way to separate the fibres by chaotization i.e. form each fibre into its unique shape. Due to this separation technique, mutual contacts of fibres are pointwise. In this paper, six chaotized polymeric hollow fibre bundles with different number of fibres were studied. The presented bundles were different by fibre diameter, number and shape. These bundles were fixed into module in the way that the middle part serves as a crossflow heat exchanger in an air tunnel. They were tested for air-water application with three different flow rates of air. The overall heat transfer coefficients were determined, and inner and outer heat transfer coefficients were derived.

Polymerní výměníky z dutých vláken jsou alternativou k běžným kovovým tepelným výměníkům v nízko-teplotních aplikacích. Jejich výhodami jsou nízká cena, nízká hmotnost a odolnost vůči korozi. Teplosměnná plocha se sestává ze stovky nebo dokonce tisíce vláken malého průměru. Aby byl zajištěn kontakt vlákna s okolním proudem tekutiny je třeba vlákna oddělit jedno od druhého. Jednoduchý způsob jak tohoto dosáhnout je chaotizace tj. každé vlákno má svůj unikátní tvar. Díky této separaci, vzájemné kontakty vláken jsou bodové. V tomto čláku je studováno šest chaotizovaných polymerních svazků z dutých vláken s různým počtem vláken.

Polymeric hollow fibre heat exchangers are an alternative to common metal heat exchangers in low temperature applications. Their advantages are low cost, low weight and corrosion resistance. The heat transfer surface consists of hundreds or even thousands of fibres of small diameter. In order to provide direct contact of fibres with the surrounding stream of fluid there is need to separate fibres from each other to let fluid flow between. There is simple way to separate the fibres by chaotization i.e. form each fibre into its unique shape. Due to this separation technique, mutual contacts of fibres are pointwise. In this paper, six chaotized polymeric hollow fibre bundles with different number of fibres were studied. The presented bundles were different by fibre diameter, number and shape. These bundles were fixed into module in the way that the middle part serves as a crossflow heat exchanger in an air tunnel. They were tested for air-water application with three different flow rates of air. The overall heat transfer coefficients were determined, and inner and outer heat transfer coefficients were derived.

Polymerní duté vlákno, chaotická struktura, křížový tepelný výměník, koeficient prostupu tepla

Polymer hollow fibre, chaotic structure, crossflow heat exchanger, heat transfer coefficient

09.04.2019

Brno

978-80-214-5733-1

ERIN 2019

1

26–26

1