Plate fin-and-tube heat exchanger computational fluid dynamics model

Lindqvist, Karl; Skaugen, Geir; Meyer, Ole Hauke Heinz

doi:10.1016/j.applthermaleng.2021.116669

Cited by 26 publications

(9 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Khan et al [10] investigated twisted oval tube HEXs and designated the average Nusselt numbers and pressure drop correlations. Lindqvist et al [11] conducted CFD research taking into account different tube bundle array angles. They also presented diagrams with the Colburn factors for low Reynold numbers.…”

Section: Introductionmentioning

confidence: 99%

Thermal Calculations of Four-Row Plate-Fin and Tube Heat Exchanger Taking into Account Different Air-Side Correlations on Individual Rows of Tubes for Low Reynold Numbers

Marcinkowski

Taler

et al. 2021

Energies

View full text Add to dashboard Cite

Currently, when designing plate-fin and tube heat exchangers, only the average value of the heat transfer coefficient (HTC) is considered. However, each row of the heat exchanger (HEX) has different hydraulic–thermal characteristics. When the air velocity upstream of the HEX is lower than approximately 3 m/s, the exchanged heat flow rates at the first rows of tubes are higher than the average value for the entire HEX. The heat flow rate transferred in the first rows of tubes can reach up to 65% of the heat output of the entire exchanger. This article presents the method of determination of the individual correlations for the air-side Nusselt numbers on each row of tubes for a four-row finned HEX with continuous flat fins and round tubes in a staggered tube layout. The method was built based on CFD modelling using the numerical model of the designed HEX. Mass average temperatures for each row were simulated for over a dozen different airflow velocities from 0.3 m/s to 2.5 m/s. The correlations for the air-side Nusselt number on individual rows of tubes were determined using the least-squares method with a 95% confidence interval. The obtained correlations for the air-side Nusselt number on individual rows of tubes will enable the selection of the optimum number of tube rows for a given heat output of the HEX. The investment costs of the HEX can be reduced by decreasing the tube row number. Moreover, the operating costs of the HEX can also be lowered, as the air pressure losses on the HEX will be lower, which in turn enables the reduction in the air fan power.

show abstract

Section: Introductionmentioning

confidence: 99%

Thermal Calculations of Four-Row Plate-Fin and Tube Heat Exchanger Taking into Account Different Air-Side Correlations on Individual Rows of Tubes for Low Reynold Numbers

Marcinkowski

Taler

et al. 2021

Energies

View full text Add to dashboard Cite

show abstract

“…The SST model is also characterized by very good accuracy of the numerical solutions for wall-bounded, complicated geometry flows, obtained with relatively low computational power. Recently, Lindqvist et al have performed an extensive analysis of RANS turbulence models in the application to numerical simulation of airflow and heat transfer in plate-fin and tube heat exchangers [18]. The k-ω SST was chosen as optimal and used for further validation against experimental data.…”

Section: Boundary Conditions and Governing Equationsmentioning

confidence: 99%

Study of the Influence of the Lack of Contact in Plate and Fin and Tube Heat Exchanger on Heat Transfer Efficiency under Periodic Flow Conditions

et al. 2021

View full text Add to dashboard Cite

Plate fin-tube heat exchangers are widely used in air conditioning and refrigeration systems and other industry fields. Various errors made in the manufacturing process can result in the formation of an air gap between the tube and fin. Several numerical simulations were carried out for a symmetric section of plate fin-tube heat exchanger to study the influence of air gap on heat transfer under periodic flow conditions. Different locations and sizes of an air gap spanning 1/2 circumference of the tube were considered for the range of airflow velocities. Velocity and temperature fields for cases with air gap were compared with ideal thermal contact cases. Blocking of heat flow by the gap leads to the reduction of heat transfer rate. Fin discontinuity in the front of the tube causes the smallest reduction of the heat transfer rate in comparison to the ideal tube-fin contact, especially for thin slits. The rear gap position is the worst in the smallest gap range. Therefore, reversing the flow direction can lead to up to a 15% heat transfer increase, if mainly the rear gaps are present. The introduction of a thin slit in the front of the tube leads to convective heat transfer enhancement, which should be further investigated.

show abstract

“…The correlation from Granryd [27] was used for the airside heat transfer and pressure drop. This model is also described by Verma et al [28] and validated against experiments and CFD by Lindqvist et al [29]. The evaporator is calculated as a dry expansion type where the evaporation temperature and degree of superheat are defined at the outlet, specified by the pressure and temperature upstream of the expansion valve.…”

Section: Hxsimmentioning

confidence: 99%

Numerical Study of Hydrocarbon Charge Reduction Methods in HVAC Heat Exchangers

et al. 2021

Self Cite

View full text Add to dashboard Cite

Required refrigerant charge in heat pump systems with propane is analyzed. Two systems are compared: the first a direct heat pump, with fin-and-tube heat exchangers, and the second an indirect system, with plate heat exchangers with an additional brine-to-air heat exchanger. Each system was considered to be able to work reversibly, with 5~kW design cooling capacity in summer and 8~kW design heating capacity in winter. Two separately developed simulation codes were used to calculate the required refrigerant charge and the efficiency of each of the systems. The charge was reduced by the use of microfinned tubes up to 22% in direct system reduced using microfinned tubes compared to the smooth tube. For the indirect system using specially designed plate heat exchangers with the minimum internal volume, their charge was reduced by up to 66% compared to normal plate heat exchangers.

show abstract

Plate fin-and-tube heat exchanger computational fluid dynamics model

Cited by 26 publications

References 20 publications

Thermal Calculations of Four-Row Plate-Fin and Tube Heat Exchanger Taking into Account Different Air-Side Correlations on Individual Rows of Tubes for Low Reynold Numbers

Thermal Calculations of Four-Row Plate-Fin and Tube Heat Exchanger Taking into Account Different Air-Side Correlations on Individual Rows of Tubes for Low Reynold Numbers

Study of the Influence of the Lack of Contact in Plate and Fin and Tube Heat Exchanger on Heat Transfer Efficiency under Periodic Flow Conditions

Numerical Study of Hydrocarbon Charge Reduction Methods in HVAC Heat Exchangers

Contact Info

Product

Resources

About