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Description
Plate fin and tube heat exchangers (PFTHE) have plenty applications in heating and cooling technics e.g. cooling towers, dry coolers and air coolers in the food industry, oil coolers in car engines, air coolers and heaters in ventilation, refrigerant coolers and heat pumps in air conditioning. Is it possible to optimize the construction of the PFTHE? It would seem that the current process of design of PFTHE cannot be more optimal.
The classical method of calculating PFTHE is based on the average logarithmic difference of medium temperatures. It assumes that the air-side heat transfer coefficient on every row of PFTHE is constant. Computational fluid dynamics (CFD) simulation studies and experimental results show that there are significant differences in coefficient between an individual row of tubes. This is true especially if air velocity in front of PFTHE is smaller than 2.5 m/s. It is possible to consider different coefficients on each row of tubes. Taking into account these dependencies between heat transfer coefficient and the row’s position will allow optimal PFTHE design e.g. it will eliminate 4-row PFTHEs in favour of 1- or 2-row PFTHEs. Following optimization gives us a chance to significantly reduce materials for building PFTHEs.
The main objective of the research is to create a new method of calculation and experimental studies of cross-flow heat exchanger made from tubes with individual or continuous fins. This new method will be determined based on experimental and numerical research. An analytical and numerical model of 2-row and 4-row PFTHE will be developed. New method can be used during the cross-flow heat exchanger design or optimization.
The test facility will be built for the needs of experimental determination of the Nusselt number for air-side and water-side in PFTHEs. The stand will allow aerodynamic, hydraulic and thermal tests in steady and transient conditions.