Experimental and computational analysis of ribbing structure modification effect in tube and fin cross-flow heat exchangers operating at non-uniform inflow of media

• Autorzy: Bury T. , Hanuszkiewicz-Drapała M.
• Języki publikacji: EN

Abstrakty

EN

Distributions of media streams flowing in a cross-flow tube and fin heat exchanger are usually non-uniform. This could be an effect of the heat exchanger construction, its installation method, design of a flowing channel or all those factors combined. The problem of the non-uniform media flow in heat exchangers of different types is not new, and it has been investigated by many researchers. Early results were sometimes ambiguous. More recent outcomes indicate that the effect of the non-uniform inflow of heat carriers to the heat exchanger could be significant it may adversely affect the device’s efficiency to a large extent. Investigations of tube and fin cross-flow heat exchangers carried out for almost twenty years at the Institute of Thermal Technology of the Silesian University of Technology, by way of experiments and numerical simulations, also confirm these latest conclusions. The reduction in overall heat exchanger capacity, comparing to the uniform inflow of media, may reach up to 18%. This work presents results of experimental and computational investigations of tube, fin, cross-flow, double row heat exchangers air-water. The heat exchangers under consideration are built in the form of two rows of elliptic tubes with rectangular fins. The ribbing structure of the first heat exchanger is uniform. This device was investigated primarily in order to determine its efficiency but also the range and the form of non-uniform inflow of air. The air flow distribution was tested on a special test station during a series of measurements. The results of the analysis of this heat exchanger were used to design a second heat exchanger with a non-uniform structure of fins on individual tubes. It was assumed that by changing the heat transfer surface (thickening the fins) in the region of high air speed, the efficiency of modified heat exchangers could be enhanced. Testing this hypothesis is the main aim of this work. The experimental results generally confirm the hypothesis, showing a rise in efficiency of up to 8%. However, it should be noted that the design of the modified ribbing structure is not optimal and changing this structure impacts the hydraulic resistance and distribution of air mass flow rate at the heat exchanger inflow. This effect should be considered when evaluating the results.

Słowa kluczowe

EN

tube heat exchanger; cross-flow heat exchanger; non-uniform media inflow

PL

wymiennik ciepła rurowy; wymiennik ciepła krzyżowoprądowy; przepływ nierównomierny

• Wydawca: Institute of Heat Engineering, Warsaw University of Technology
• Czasopismo: Journal of Power Technologies
• Rocznik: 2017
• Tom: Vol. 97, nr 5
• Strony: 429--436
• Opis fizyczny: Bibliogr. 20 poz., rys., tab.

Twórcy

autor

Bury T.

• Institute of Thermal Technology, Silesian University of Technology, ul. Konarskiego 22, 44-100 Gliwice, Poland

autor

Hanuszkiewicz-Drapała M.

• Institute of Thermal Technology, Silesian University of Technology, ul. Konarskiego 22, 44-100 Gliwice, Poland

Bibliografia

• [1] X. Luo, W. Roetzel, U. Lüdersen, The single-blow transient testing technique considering longitudinal core conduction and fluid dispersion, International Journal of Heat and Mass Transfer 44 (1) (2001) 121–129.
• [2] N. Srihari, S. K. Das, Transient response of multi-pass plate heat exchangers considering the effect of flow maldistribution, Chemical Engineering and Processing: Process Intensification 47 (4) (2008) 695–707.
• [3] K. Shaji, S. K. Das, The effect of flow maldistribution on the evaluation of axial dispersion and thermal performance during the singleblow testing of plate heat exchangers, International Journal of Heat and Mass Transfer 53 (7) (2010) 1591–1602.
• [4] R. Berryman, C. Russell, The effect of maldistribution of air flow on aircooled heat exchanger performance, Maldistribution of flow and its effect on heat exchanger performance, JB Kitto, JM Robertson ASME Htd 75 (1987) 19–23.
• [5] C. Meyer, D. Kröger, Plenum chamber flow losses in forced draught aircooled heat exchangers, Applied Thermal Engineering 18 (9) (1998) 875–893.
• [6] S. Nair, S. Verma, S. Dhingra, Rotary heat exchanger performance with axial heat dispersion, International Journal of Heat and Mass Transfer 41 (18) (1998) 2857–2864.
• [7] K.-S. Lee, S.-J. Oh, Optimal shape of the multi-passage branching system in a single-phase parallel-flow heat exchanger, International Journal of Refrigeration 27 (1) (2004) 82–88.
• [8] A. Korzeń, D. Taler, Modeling of transient response of a plate fin and tube heat exchanger, International Journal of Thermal Sciences 92 (2015) 188–198.
• [9] D. Taler, M. Trojan, J. M. Taler, Mathematical modeling of cross-flow tube heat exchangers with a complex flow arrangement, Heat Transfer Engineering 35 (14-15) (2014) 1334–1343.
• [10] B. Sundén, Computational fluid dynamics in research and design of heat exchangers, Heat Transfer Engineering 28 (11) (2007) 898–910.
• [11] M. M. A. Bhutta, N. Hayat, M. H. Bashir, A. R. Khan, K. N. Ahmad, S. Khan, Cfd applications in various heat exchangers design: A review, Applied Thermal Engineering 32 (2012) 1–12.
• [12] S. Jun, V. M. Puri, 3d milk-fouling model of plate heat exchangers using computational fluid dynamics, International journal of dairy technology 58 (4) (2005) 214–224.
• [13] E. Dario, L. Tadrist, J. Oliveira, J. Passos, Measuring maldistribution of two-phase flows in multi-parallel microchannels, Applied Thermal Engineering 91 (2015) 924–937.
• [14] Z. Zhang, S. Mehendale, J. Tian, Y. Li, Experimental investigation of distributor configuration on flow maldistribution in plate-fin heat exchangers, Applied Thermal Engineering 85 (2015) 111–123.
• [15] S. Datta, P. Das, S. Mukhopadhyay, Performance of a condenser of an automotive air conditioner with maldistribution of inlet air - simulation studies and its experimental validation, International Journal of Heat and Mass Transfer 98 (2016) 367–379.
• [16] R. Piątek, Analiza termodynamiczna ożebrowanego wymiennika ciepła z nierównomiernym dopływem czynników [Thermal analysis of a plate-and-fin tube heat exchanger with a non-uniform inflow of mediums], Ph.D. thesis, Institute of Thermal Technology, Silesian University of Technology, Poland (2003).
• [17] T. Bury, J. Składzień, M. Hanuszkiewicz-Drapała, Experimental and numerical analyses of a non-uniform agents flow impact on a finned cross-flow heat exchanger effectiveness, in: Proceedings of the 22nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems - ECOS 2009, Foz do Iguacu, Parana, Brazil, 2009.
• [18] K. Widziewicz, Analiza termodynamiczna krzyżowoprądowego wymiennika ciepła z uwzględnieniem nierównomierności dopływu czynników i promieniowania cieplnego [Thermodynamic analysis of a cross-flow heat exchanger including a non-uniform inflow of mediums and the radiative heat transfer], Ph.D. thesis, Institute of Thermal Technology, Silesian University of Technology, Poland (2014).
• [19] T. Bury, J. Składzień, The experimental and the numerical analysis of a ribbed heat exchanger with an unequal inlet of the air, Proceedings of Heat Transfer and Renewable Sources of Energy (2006) 419–426.
• [20] T. Bury, J. Składzień, Evaluation of selected methods of mitigation of media flow maldistribution impact in finned cross-flow heat exchangers., in: 3rd International Conference on Contemporary Problems of Thermal Engineering, Gliwice, 2012.

Uwagi

PL

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).