Experimental implementation of thermal enhancement performance of air heat exchanger’s pipes utilizing unconventional turbulator
Open Access
- 27 May 2021
- journal article
- Published by OU Scientific Route in EUREKA: Physics and Engineering
- No. 3,p. 35-44
- https://doi.org/10.21303/2461-4262.2021.001850
Abstract
Heat exchangers are widely used in industry, however, raising their performance are important for the variety of applications. Consequently, efficiency improvement associated with low production cost is considered in this experimental work. The current study aims to enhance the rate of heat transfer in pipe-type heat exchangers experimentally by using a novel nozzle as a turbulator. The cross-sectional shape of the nozzle is hexagonal, and the diameter ratio DR is equal to 0.5. Constant heat flux was maintained in the vicinity of the section of the test tube, while the working fluid was pumped into the open system at six discrete Reynolds number values ranging from 6000 to 19500. To investigate the effect of distance among the pieces, three turbulators with different numbers were assigned and named as (N=4, 5 and 6). The results indicated an increase of 172 %, 194 % and 216 % of the heat transfer rate for cases 4, 5 and 6 respectively comparing to the benchmark tube. On the other hand, the friction factor values increased remarkably due to the inserting of turbulators by about of 722.9 % for N=4, 823.9 % for N=5 and 886.7 % for N=6 compared to a plain tube case. Moreover, it has been established that with the insertion of 6 pieces two enhancements was observed; heat transfer rate and thermal performance, where, thermal performance of all cases exceeds unity (maximum thermal performance of 1.62 has been obtained by inserting 6 pieces of hexagonal nozzles turbulators). A comparison with another types of vortex generators shows the gap between the turbulator and heated surface offers a solution for problems occurred in the pipes of heat exchanger. The study therefore suggests a wider practical implementation of the turbulatorsKeywords
This publication has 13 references indexed in Scilit:
- Thermal performance of tube exchanger enhanced with hexagonal ring turbulatorsExperimental Heat Transfer, 2019
- Heat transfer enhancement of heat exchanger tube with multiple square perforated twisted tape inserts: Experimental investigation and correlation developmentChemical Engineering and Processing - Process Intensification, 2017
- Experimental study on effect of heat transfer enhancement for single-phase forced convective flow with twisted tape insertsInternational Journal of Heat and Mass Transfer, 2017
- Effect of conical cut-out turbulators with internal fins in a circular tube on heat transfer and friction factorInternational Communications in Heat and Mass Transfer, 2013
- Experimental investigation of heat transfer and turbulent flow friction in a tube fitted with perforated conical-ringsInternational Communications in Heat and Mass Transfer, 2010
- Heat transfer enhancement in a tube using delta-winglet twisted tape insertsApplied Thermal Engineering, 2010
- Heat transfer behaviors in round tube with conical ring insertsEnergy Conversion and Management, 2008
- Heat transfer augmentation in a circular tube using V-nozzle turbulator inserts and snail entryExperimental Thermal and Fluid Science, 2007
- Heat transfer in a circular tube fitted with free-spacing snail entry and conical-nozzle turbulatorsInternational Communications in Heat and Mass Transfer, 2007
- Heat transfer behaviors in a tube with combined conical-ring and twisted-tape insertInternational Communications in Heat and Mass Transfer, 2007