The role of enhancement techniques on heat and mass transfer characteristics of shell and tube spray evaporator: a detailed review

Abed, Azher M.; Alghoul, M. A.; Yazdi, M. H.; Al-Shamani, Ali Najah; Sopian, Kamaruzzaman

doi:10.1016/j.applthermaleng.2014.10.020

Cited by 52 publications

(11 citation statements)

References 144 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, for simultaneous heat and mass transfer processes, Treybal [20] proposed working with a corrected heat transfer coefficient ðh l Ã Þ, in which the effect of mass transfer on heat transfer are taken into account (Eqs. (12) and (13)). Note that the effect of mass transfer on heat transfer can improve or deteriorate the heat transfer coefficient depending on both process directions, while _ m i is the mass flow rate for the ith component…”

Section: Author Geometrical Specifications Compared Commentsmentioning

confidence: 94%

See 1 more Smart Citation

A critical review of heat and mass transfer correlations for LiBr-H 2 O and NH 3 -H 2 O absorption refrigeration machines using falling liquid film technology

Narváez-Romo¹,

Chhay

Aguilar

et al. 2017

Applied Thermal Engineering

View full text Add to dashboard Cite

show abstract

Section: Author Geometrical Specifications Compared Commentsmentioning

confidence: 94%

“…Experimental works using Ammonia Water: Configuration of study Bohra [31] Horizontal tube bundle 4Cx6R are not a heat transfer correlation for ammonia-water falling film in absorption processes using nanoparticles [12].…”

Section: Geometrical Specifications Compared Commentsmentioning

confidence: 99%

A critical review of heat and mass transfer correlations for LiBr-H 2 O and NH 3 -H 2 O absorption refrigeration machines using falling liquid film technology

Narváez-Romo¹,

Chhay

Aguilar

et al. 2017

Applied Thermal Engineering

View full text Add to dashboard Cite

show abstract

“…Such behavior can be explained by the fact, that for high enough m, more heat evaporation can be withdrawn from the tubes system with the evaporated steam. In such conditions, the number of local dry areas on the tubes surfaces decreases and the falling film mode between horizontal tubes changes from droplet mode, through the jet mode, where liquid leaves the tube as continuous columns, to the sheet mode [35].…”

Section: Effect Of the Number Of Flooded Tube Rows And The Refrigeranmentioning

confidence: 99%

“…Because of the complexity of two-phase flow in the falling film, different factors affect their heat transfer performance, including designing factors (e.g., configuration of enhanced surfaces, tube pass arrangements) and operating factors (e.g., falling film flow rate) [34]. An interesting survey of heat transfer correlations applicable for falling film evaporators can be found in [35]. The effects of tube diameter, saturation temperature, heat flux, and film flow rates on the falling film heat transfer of R134a outside a single horizontal smooth tube are given in [36].…”

Section: Introductionmentioning

confidence: 99%

A General Approach in Optimization of Heat Exchangers by Bio-Inspired Artificial Intelligence Methods

Krzywański

2019

Energies

View full text Add to dashboard Cite

The paper introduces the artificial intelligence (AI) approach as a general method for the design and optimization study of heat exchangers. Genetic Algorithms (GA) and Artificial Neural Networks (ANN) are applied in the paper. An AGENN model, combining Genetic Algorithms with Artificial Neural Networks, was developed and validated against the desired data on a large falling film evaporator. A broad range of operating conditions and geometric configurations are considered in the study. Four kinds of tubes are deliberated, including plain and enhanced tubes. Different tube pass arrangements, i.e., top-to-bottom, bottom-to-top, and side-by-side, are discussed. Finally, the effects of liquid refrigerant mass flow rate, as well as the number of flooded tubes on the performance of the evaporator, are analyzed. The total heat transfer rate of the evaporator, predicted by the model, is in good agreement with the desired data; the maximum error is lower than ±3%. The highest heat transfer rate of the evaporator is 1140.01 kW and corresponds to Turbo EHP tubes, and bottom-to-top tubes pass arrangements, which guarantee the best thermal energy conversion. The presented approach can be referred to as a complementary technique in heat exchanger design procedures, besides the common rating and sizing tasks. It is an effective and alternative method for the existing approaches, considering the complexity of analytical and numerical techniques as well as the high costs of experiments.Construction features of the direct-transfer-type heat exchangers are the base of their classification, according to the geometry of construction criterion. Considerable flexibility in heat exchangers design can be observed for tubular ones where tube diameter, the number of tubes, the tube length, the pitch of the tubes, and the tube arrangement can be easily modified. Tubular heat exchangers can be classified into double-pipe, shell-and-tube and spiral-tube-type heat exchangers as heat transfer coefficients in a spiral tube are higher than those in a straight one. Plate heat exchangers are built of thin plates (plain, wavy, or corrugated) forming flow channels and can be categorized into: gasketed plate (consists of a series of thin plates with corrugation or wavy surfaces that separate the fluids), spiral plate (formed by rolling two long, parallel plates into a spiral), and lamella (Ramen) type of heat exchanger (a set of parallel, thin plate channels or lamellae (flat tubes or rectangular channels) placed longitudinally in a shell) [2].Extended surface heat exchangers contain fins or appendages on primary heat transfer surfaces to increase the heat transfer area (usually on the gas side).According to the heat transfer mechanisms criterion, there can be distinguished: 1. single-phase convection on both sides, 2. single-phase convection on one side and two-phase convection on other side, 3. two-phase convection on both sides.Finally, according to the flow arrangements criterion, the following fluid-flow path through the heat exchanger can exist:...

show abstract

“…The results indicated that the evaporation heat transfer was higher on the porous tube, while sensible heat transfer was almost the same. Other than this, several studies on the porous structure surface, as a falling film heat transfer enhancement technique, have been conducted [15]. However, most of these studies are on water vaporization, and only a few reports have investigated the application of falling film evaporation in fluorocarbons, where nucleate boiling occurs more actively than in water.…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer Enhancement of Falling Film Evaporation on a Horizontal Tube by Thermal Spray Coating

2020

View full text Add to dashboard Cite

Falling film evaporators are gaining popularity as substitutes to typical flooded evaporators because of their low refrigerant charge. It is important to form and keep a thin liquid film on the heat transfer surface to ensure their high heat transfer performance. In this study, as a heat transfer enhancement surface, a fine porous surface processed using thermal spray coating was applied to a smooth copper tube with an outer diameter of 19.05 mm. Heat transfer coefficients of falling film evaporation on a single horizontal tube were experimentally evaluated using the HFC-134a refrigerant. The experiments were performed at a saturation temperature of 20 °C with the heat flux ranging from 10 to 85 kW·m−2 and for film Reynolds numbers up to 673. The study aimed to clarify the effect of the coating on the heat transfer characteristics of falling film evaporation. The results revealed that the coating could suppress partial dry out and enhance nucleate boiling in the falling film. The maximum heat transfer enhancement factor was 5.2 in the experimental range. It was further noted that the effect of the coating was especially strong under a low heat flux condition.

show abstract

The role of enhancement techniques on heat and mass transfer characteristics of shell and tube spray evaporator: a detailed review

Cited by 52 publications

References 144 publications

A critical review of heat and mass transfer correlations for LiBr-H 2 O and NH 3 -H 2 O absorption refrigeration machines using falling liquid film technology

A critical review of heat and mass transfer correlations for LiBr-H 2 O and NH 3 -H 2 O absorption refrigeration machines using falling liquid film technology

A General Approach in Optimization of Heat Exchangers by Bio-Inspired Artificial Intelligence Methods

Heat Transfer Enhancement of Falling Film Evaporation on a Horizontal Tube by Thermal Spray Coating

Contact Info

Product

Resources

About