Horizontal Smooth Tube Research Articles

Pressure Drop Estimation of Two-Phase Adiabatic Flows in Smooth Tubes: Development of Machine Learning-Based Pipelines

The current study begins with an experimental investigation focused on measuring the pressure drop of a water–air mixture under different flow conditions in a setup consisting of horizontal smooth tubes. Machine learning (ML)-based pipelines are then implemented to provide estimations of the pressure drop values employing obtained dimensionless features. Subsequently, a feature selection methodology is employed to identify the key features, facilitating the interpretation of the underlying physical phenomena and enhancing model accuracy. In the next step, utilizing a genetic algorithm-based optimization approach, the preeminent machine learning algorithm, along with its associated optimal tuning parameters, is determined. Ultimately, the results of the optimal pipeline provide a Mean Absolute Percentage Error (MAPE) of 5.99% on the validation set and 7.03% on the test. As the employed dataset and the obtained optimal models will be opened to public access, the present approach provides superior reproducibility and user-friendliness in contrast to existing physical models reported in the literature, while achieving significantly higher accuracy.

Condensation heat transfer of zeotropic refrigerant mixtures R407C and R448A in a horizontal smooth tube

Zeotropic refrigerant blends have attracted wide interest due to their promises to reduce global warming potential as well as their potential ability to improve the performance of heat pumps and air conditioners. The complex phenomenon of non-isothermal phase change complicates condensation of zeotropic refrigerant mixtures and merits extensive investigation to better understand their performance profiles. The present work experimentally studied condensation heat transfer of R407C and R448A – two R134a-based zeotropic refrigerant mixtures – in a horizontal smooth tube, condensed by counter-current water cooling. Measurements for mass flux were in the range of 120 to 320 kg m−2s−1 and saturation temperature in the range of 42 to 64 °C. Variation in refrigerant temperature and composition shift during condensation were quantitatively presented. The experimental data showed the effects of mass flux and saturation temperature on the heat transfer coefficients of R407C and R448A in different vapor quality regions. The analysis of heat and mass transfer resistances related to the flow regimes and refrigerant thermophysical properties provides a deep understanding of the condensation heat transfer of zeotropic refrigerant mixtures. The experimental data presented in this work are of value for the design of condensers.

Numerical investigation of flow boiling characteristics of R134A in a smooth horizontal tube

Three-dimensional transient simulations using ANSYS Fluentʼs mixture multiphase model was conducted to investigate the impact of heat flux, mass flux, and saturation temperature variations on pressure drop behaviour and heat transfer characteristics during flow boiling of R134a refrigerant in smooth horizontal tubes of different diameters. The simulations employ an implicit numerical method to solve the governing equations, with relevant source terms for mass and energy transfer, incorporating the continuum surface force (CSF) and shear stress transport (SST) κ-ω models to account for surface tension and flow turbulence respectively. The results are presented in both dimensional (heat transfer coefficient and pressure drop) and non-dimensional (Nusselt number and two-phase frictional factor) forms. The Nusselt number shows a direct relationship with the Reynolds number, while the two-phase friction factor exhibits different behaviour. At higher vapor quality, mass flux significantly affects heat transfer performance and pressure drop. Heat flux plays a crucial role in heat transfer, but its impact on pressure drop is negligible. Higher saturation temperatures enhance heat transfer while reducing pressure gradients. The obtained results demonstrate good agreement with existing correlations, with mean absolute deviations (MAD) as low as 1.2 % for the heat transfer coefficient and 23.7 % for the pressure drop behaviour. This highlights the model's accuracy in predicting flow boiling behaviour of R134a in smooth horizontal channels, providing valuable insights for thermal analysis. The findings contribute to the understanding of flow boiling processes and aid in designing and optimizing efficient heat exchangers for various engineering applications.

Numerical study on condensation heat transfer of R1234ze(E)/R152a in a horizontal smooth tube

Stable-state numerical simulations of the condensation heat transfer properties of the novel refrigerant NCUR01 (R1234ze(E) and R152a in a mass ratio of 4:6) have been performed using the volume of fluid (VOF) multiphase flow model. The findings demonstrate that as mass flux rises, the working substance’s fluid velocity increases at the same location within the tube, boosting the condensation heat transfer coefficient in the process. The condensation heat transfer force is strengthened by an increase in heat flux, which raises the condensation heat transfer coefficient. On the other hand, when the saturation temperature rises, the condensation heat transfer coefficient falls.

Numerical and experimental investigation on boiling heat transfer and flow attributes for the exterior of smooth tubes and T-fin tubes

Experiments and numerical analyses of saturated pool boiling have been carried out on the outer surfaces of horizontal smooth tubes and T-fin tubes. Using a computational model that closely matches the experimental results, the study examined the dynamics of the bubbles as well as the boiling heat transfer coefficients in both the circumferential and axial orientations of the T-fin tubes. For the first time, comprehensive information on the process of high-performance external tube boiling has been made available. The findings demonstrate that an increase in fin density on the surface of the T-fin tubes leads to an abundance of bubble nuclei, with the escaping bubbles exhibiting both increased size and accelerated velocity. Due to the distinctive configuration of the T-fin tube, the local heat flow is lowest at the root fin and highest at the fin tip, indicating that heat transfer is inhibited in the narrow cavity between the two lateral fins. The optimal fin density, which corresponds to the maximum overall heat transfer coefficient has been identified. This states that the enhanced heat transfer mechanism within the T-fin tube is a symbiotic effect of both the increase in heat transfer area and the subsequent degradation of heat transfer fostered by the bubbling of the tube.

Flow boiling heat transfer of R1234ze(E) in a horizontal mini-channel at medium and high saturation temperatures

This study reports experimental results of flow boiling heat transfer characteristics of R1234ze(E) (a low global warming potential refrigerant) at moderate and high saturation temperatures. The study was performed in a single horizontal circular smooth tube of 2.07 mm internal diameter. Heat transfer characteristics and flow pattern visualization through high-speed camera were investigated for saturation temperatures ranging from 60 to 95 °C, corresponding to reduced pressures from 0.35 to 0.75, mass velocities from 300 to 500 kg/m2s, heat fluxes from 30 to 50 kW/m2 and vapor qualities from 0 to 1. The pre-dryout data (214 data points) measured were compared against different prediction methods from the literature developed under different theories. The study revealed that the saturation temperature has a significant effect on heat transfer coefficient whereas the mass velocity presented a less pronounced or negligible effect. Furthermore, the heat transfer coefficient was observed to decrease slightly to a minimum in the low vapor quality region and then levels off or increases slightly with increasing vapor quality until dryout occurs. As a result, nucleate boiling was observed to be the dominant mechanism controlling the heat transfer. It was observed that the higher the saturation temperature, the earlier the vapor quality at which dryout incipience occurs. Considering the 214 pre-dryout data points analyzed, the methods proposed by Kew and Cornwell (1997), Lazarek and Black (1982) and Choi et al. (2007) were the most accurate, predicting the entire pre-dryout database with mean absolute errors (MAEs) of 13.7%, 13.9 % and 14.4 %, respectively.

Ammonia condensation in the horizontal and vertical smooth tubes

The paper proposes the experimental study of ammonia condensation in aluminium tubes with 8 mm and 11 mm internal diameters. The new study aimed to compare and extend the existing ammonia in-tube condensation data. The lines were tested mainly in horizontal configuration at mass velocities of 20 to 160 kg·m−2s−1, saturation temperature of 35 to 65 °C and inlet vapour quality of 0.1 to 0.9. Shah (1979), laminar-laminar Dobson and Chato (1998), and Cavallini et al. (2001) models predict well ammonia condensation HTCs at mass velocities of 120 to 160 kg·m−2s−1. A new phenomenological model has been proposed for the mass velocities of 20 to 120 kg·m−2s−1, predicting the test data with an accuracy of ±20 %. Similar ammonia condensation HTCs have been obtained for horizontal and upstream flows at a mass velocity above 120 kg·m−2s−1. The lowest condensation HTCs at the considered boundary conditions characterise the downstream configuration of an in-tube condenser at a mass velocity below 120 kg·m−2s−1. However, inclining the ID 8 mm tube by 15° from the normal substantially increases the condensation HTCs by 10 to 30 %, depending on vapour quality. At the inclinations of 15 to 45° from the horizontal line toward the downstream flow, the condensation HTCs exceed the ones of horizontal flow by 10 to 15 % at the vapour quality of <0.5 and low mass velocity of 80 kg·m−2s−1.

Experimental study and performance evaluation of an air source heat pump (ASHP) system with a frost-free evaporator

The air source heat pump (ASHP) is operated in a low temperature and high humidity working environment. There is always a lot of frost forming on the outdoor heat exchanger, which hinders the heat transfer rate of the heat exchange surface, leading to the decrease of performance of the ASHP system. This paper presents a new type of frost-free evaporator for ASHP system. The heat transfer zone of the evaporator is composed of three parts: non-packing zone, plain finned-tube falling film zone and horizontal smooth tube bundle falling film zone. The experimental system of the frost-free evaporator is established, and the reliability of the experimental data is verified. The effects of refrigerant flow rate, inlet air temperature, fan frequency and solution spray mode on energy efficiency ratio, heat transfer expansion coefficient, air side pressure drop and exergy loss of the evaporator are studied. The performance of the evaporator is evaluated. The results show that with the increase of inlet air flow and temperature, the energy efficiency ratio of frost-free evaporator increases by about 8%–12%, and the air side pressure drop also increases. As the inlet air temperature increases from −10 to 15 °C, the heat transfer expansion coefficient of evaporator decreases by about 3%–6%, indicating that the increase of inlet air temperature will lead to an increase of sensible heat transfer ratio and a decrease of latent heat transfer ratio. The results also show that compared with no spray mode and continuous spray mode, the intermittent spray mode is more recommended as a feasible operation scheme to realize the continuous, efficient and stable operation of the new evaporator.

Ammonia single-phase and two-phase frictional pressure losses in horizontal smooth and straight inner-grooved tubes

The experimental study of single-phase and two-phase frictional pressure losses has been performed with ammonia flow in stainless steel smooth tubes (internal diameter of 5.5 mm and 8.5 mm) and six straight inner-grooved aluminium tubes with different nominal diameters (7.15 to 13.3 mm), length (0.45 to 2.0 mm) and thickness (0.35 to 0.8) of fins. Single-phase test boundary conditions correspond to Reynolds numbers of 1000 to 20,000. Two-phase tests have been carried out at saturation temperature of 45 to 65 °C, mass velocity of 50 to 210 kg·m−2s−1 and vapour quality of 0.1 to 0.9. Comparison of obtained test data with the existing frictional losses approaches shows that the Blasius model is appropriate to single-phase flows in smooth tubes, and Müller-Steinhagen and Heck's (1986) model is most accurate in predictions of two-phase frictional losses in smooth tubes. Existing approaches of single-phase frictional pressure loss predictions in the pipes and channels with longitudinal fins (Carnavos, 1980; Edwards and Jensen, 1994) are not adequately suited to the ammonia test points obtained in the considered straight inner-grooved tubes. A new semi-empirical model has been proposed, based on generalisation around the revealed geometric dimensionless factor, which accurately describes friction pressure losses in the considered inner-finned profiles. The simplest homogeneous model for defining two-phase friction pressure losses, using McAdams et al.'s (1942) recommendation for mixture dynamic viscosity definition and a new model of single-phase friction factor, best fit both quantitatively and qualitatively to ammonia two-phase test points in most of the considered straight inner-grooved tubes.

Effect of viscosity grade (POE) on the smooth-tube pool boiling performance with R-1234ze(E) refrigerant

In this study, the nucleate boiling heat transfer performance for R-1234ze(E) subject to lubricant oil is reported. The viscosity grade ranges from low viscosity (68 cSt) to high viscosity (220 cSt) and the tested POE oils include POEA-68, POEA-170, POEC-170, POEA-220, and POEC-220 on a horizontal smooth copper tube. The 30 different refrigerant-oil mixtures were prepared by varying the oil mass concentration ranging from 1 % to 10 % and the corresponding saturation temperatures are 10 °C, 0 °C, and − 6 °C with heat flux ranging from 10 to 90 kW/m2. The results showed that all grades of POE oils are compatible and completely miscible with low GWP refrigerant R-1234ze(E) in the given test range. The present study reveals that the heat transfer characteristics of each refrigerant-oil mixture very much depend on the saturated temperature, heat flux, oil mass concentration, and operating pressure. The highest mass concentration (10 %) consistently deteriorates the heat transfer coefficient (HTC). However, the degradation of HTC with R-1234ze(E) is comparatively less severe than that of R-134a/POE mixture. It is found that a 3 % oil concentration is regarded as the threshold concentration for the highest enhancement in the HTC when compared to the pure refrigerant. The performances of other oil concentrations such as 1 % and 5 % are subject to saturation temperature, heat flux, and evaporator pressure. In terms of the influence of saturation temperature on HTC of the mixture, it was observed that among all the grades of oil, POEC-170 oil shows peculiar behavior and its performance is independent of saturation temperature.

Convective condensation of R449a inside a smooth tube

The HVAC sector has started the phase-out of refrigerants characterized by high values of global warming potential and atmospheric lifetime. Drop-in replacement requires that the new, environmentally safe fluids also show comparable heat transfer performances. This work addresses R449a, a low GWP zeotropic mixture (components: R32, R125, R1234yf, R134a, mass fractions: 24.3%, 24.7%, 25.3%, 25.7%, respectively), suitable to replace both R404A and R507A. Experiments were carried out on condensation in horizontal smooth tubes (outer diameter: 9.52 mm, thickness: 0.3 mm). The range of operating conditions meets the standard for HVAC devices (operating pressure: 14.46 bar, bubble temperature: 30°C, temperature glide: approximately 5 K refrigerant mass flux ranging from 136 to 202 kg m−2 s−1, quality change -0.8 and -0.2, mean quality ranging from 0.2 to 0.8). The test section is the inner pipe in a tube-in-tube counter-flow heat exchanger, where the refrigerant is cooled by a demineralized water stream in the annulus. Both the pressure drop and the heat transfer coefficient were measured across a length of 1.3 m and 1.1 m, respectively.

Experimental investigation on flow boiling heat transfer characteristics of R245fa/oil mixture in horizontal smooth tube

During the operation of the Organic Rankine Cycle (ORC) system, it's inevitable that the lubricating oil in the expander will mix with the working fluid, leading to a noticeable impact on its heat transfer performance. In this investigation, we conducted experimental research on the flow boiling heat transfer characteristics of a mixture of R245fa and POE (Polyolester) in a smooth horizontal tube. We explored the effects of various parameters, including oil concentration (ranging from 0% to 4%), heat flux (6 to 20 kW/m²), mass flux (ranging from 150 to 410 kg/(m²·s)), and vapor quality (ranging from 0 to 0.8). The results revealed that the heat transfer coefficient (HTC) for R245fa/POE increased with higher vapor quality and mass flux for each oil concentration. However, as the oil concentration increased, the rate of increase in HTC gradually diminished. Notably, an optimal oil concentration of 2.3% was identified to achieve a maximum HTC of 6 kW/(m²·K) in our experiments. Furthermore, our investigation into frictional pressure drop (FPD) indicated that higher vapor quality, mass flux, and heat flux all led to an increase in FPD for the R245fa/POE mixture. Additionally, we evaluated the impact of lubricants on the HTC and FPD of R245fa/POE mixtures using enhancement factor (EF) and penalty factor (PF), respectively. The EFs for HTC in the R245fa/POE mix ranged mainly between 0.95 and 1.6, while the PFs for FPD were concentrated between 0.75 and 1.4. The lubricating oil was found to enhance the flow boiling heat transfer performance of R245fa, with a comprehensive evaluation index range of 1.22 to 1.31. In terms of prediction accuracy, the Schlager-R22/150SUS correlation provided the most reliable estimates for the enhancement factor of HTC and the penalty factor of FPD, with mean absolute deviations (MAD) of 9.79% for EF and 14.03% for PF.

Condensation Heat Transfer Experiments of R410A and R32 in Horizontal Smooth and Enhanced Tubes

Abstract A horizontal smooth copper tube and two enhanced tubes (a dimpled tube and a diamond-shaped tube) with a length of 2 m and an outer diameter of 9.52 mm were studied in a two-phase condensation experiment using R410A and R32 as heat transfer working fluids. The condensation heat transfer performance of different heat transfer tubes at various mass fluxes ranging from 150 to 400 kg/(m2s) and different vapor qualities ranging from 0.8 to 0.2 was studied experimentally. For R410A, the heat transfer coefficients (HTCs) of the dimpled tube and the diamond-shaped tube were found to be 1.39–1.52 times and 1.30–1.35 times higher than those of the smooth tube, respectively. For R32, the HTCs were found to be 1.46–1.59 times higher for the dimpled tube and 1.26–1.35 times higher for the diamond-shaped tube than for the smooth tube. The diamond-shaped tube was found to be effective in directing the flow of the liquid phase and in thinning the liquid film thickness. The dimpled tube was found to promote droplet entrainment and disturbance. Both of those effects contributed to improving the HTCs in the two enhanced tubes investigated. The HTCs of R410A were found to be lower than those of R32 because of the smaller specific heat capacity, smaller latent heat of condensation, and relatively poorer thermal conductivity of R410A. Taking the combined effect of heat transfer and pressure drop into account, a performance enhancement factor (PEF) was computed and was found to range from 0.9 to 1.51. Based on the experimental data collected, a new empirical correlation equation has been proposed with a maximum error band of 10%. Flow pattern maps for the tested tubes have also been generated and are presented in the paper. Both of the two enhanced tubes were found to promote the development of annular flow. The HTCs were found to be highest when the flow pattern was of the annular flow type.

Flow boiling heat transfer characteristics of zeotropic refrigerant/oil mixtures in horizontal smooth tube

In the Organic Rankine Cycle (ORC), the lubricant is inevitably mixed with the working fluid, which affects its flow boiling heat transfer characteristics in the evaporator. In this study, the flow boiling heat transfer characteristics of zeotropic fluid R141b/R245fa at different polyester oil (POE) concentrations were experimentally investigated. Meanwhile, the effects of heat flux, mass flux and vapor quality were also investigated. The results show that both the mass flux and vapor quality can increase heat transfer coefficient (HTC) and frictional pressure drop (FPD), while the heat flux decreases the HTC and increase the FPD. The maximum promotion of HTC is achieved at an oil concentration of 2.3% compared to other concentrations. Except for the oil concentration of 3%, the FPD of R141b/R245fa-POE mixture increases with the oil concentration. Additionally, the effects of lubricant oil on the HTC and FPD of refrigerant/POE mixture were discussed. The Schager-R22/150-SUS correlation can well predict the enhancement factor of HTC and penalty factor of FPD. The comprehensive factor is always greater than 1, so POE can enhance the overall heat transfer performance of refrigerant-POE mixture.

Experimental study of the heat transfer coefficient during condensation of refrigerant R1234yf in a 4.8-mm internal diameter smooth horizontal tube

Experimental study of the heat transfer coefficient during condensation of refrigerant R1234yf in a 4.8-mm internal diameter smooth horizontal tube

Numerical simulation on flow boiling heat transfer of R1234ze(E)/R152a in a horizontal smooth tube

The understanding of two-phase flow and heat transfer characteristics of refrigerants in tubes is important for guiding the design and optimization of heat exchangers. Based on the volume of fluid (VOF) multiphase model, this paper established a numerical model of R1234ze(E)/R152a (mass ratio of 0.4/0.6) flow boiling heat transfer in a horizontal smooth copper tube with an inner diameter of 6 mm and a length of 900 mm. The distribution of vapor volume fraction is obtained, and the influence of mass flux, heat flux, saturation temperature, and vapor quality on heat transfer coefficient (HTC) are studied. Bubble flow, plug flow, stratified flow, and wavy flow can be observed during the whole process and the fluid temperature increases along the tube. Local and time-averaged heat transfer coefficients and temperature distribution along the axial direction were studied. And the results indicate that the HTC decreases first and then increases with the augmentation of mass flux while increasing with the rise of heat flux. In addition, the HTC rises along with saturation temperature and decreases along with vapor quality. The largest related standard deviation between the simulation value and the testing data is 6.31%. Thus, the numerical simulation has a high level of accuracy.

Experimental study of refrigerant condensation heat transfer and pressure drop in horizontal tubes with full and partial coiled wire inserts (CWIs)

The condensation heat transfer coefficient (HTC) and pressure loss in the horizontal smooth and wire-inserted tubes were investigated experimentally. Three different coiled wire inserts (CWIs) of the full length of 1000 mm and partial lengths of 100 mm and 200 mm with 0.8 mm wire thickness and 9.5 mm pitch were studied. The main condenser was a heat exchanger of double pipe type with an 8 mm inner diameter for the refrigerant and an active length of 1 m cooled by water circulating in the annulus. The experiments were conducted for different refrigerant mass velocities within 90–400 kg/m2s and low vapor mass fraction (x < 0.3). The findings revealed that using 1000 mm (full-length), 200 mm, and 100 mm length CWIs improved the HTC by 95%, 40%, and 18%, respectively, over the smooth tube. The HTC per unit pressure drop was also evaluated to assess the performance of full and partial CWIs. The results showed that the HTC per unit pressure loss decreases for all tubes as the mass velocity increases. In addition, the performance of the tubes with CWIs approached that of the smooth tube at higher mass velocities. The ratios of HTC per unit pressure drop at higher mass fluxes for full-length, 200 mm, and 100 mm length CWIs to that of the smooth tube were about 0.4, 0.78, and 0.9, respectively. Although the pressure drop increased almost linearly with the partial CWI length, the HTC increased sharply for the small inserts and gradually for the larger insert lengths. The results obtained for the condensation HTC in smooth and full wire-inserted tubes were also compared with the estimations of well-known correlations in the literature. Furthermore, three new correlations were developed to predict condensation HTC in smooth tubes and tubes with full and partial CWIs. It was shown that the new correlations are more accurate than the available ones.

Flow and heat transfer features during propane (R290) and isobutane (R600a) boiling in a tube

The purpose of this paper is to present a numerical study of the flow and heat transfer characteristics during boiling of two hydrocarbon-based natural refrigerants, namely propane (R290) and isobutane (R600a) in a smooth horizontal tube of 10.0 mm internal diameter. The cross-sectional average heat transfer coefficients are obtained using the temperatures at the top, bottom, left and right sides of the tube. Trends of the heat transfer coefficient are displayed for different operating conditions in terms of saturation temperature (5 — 65 °C) and heat flux (9 — 24 kW/m2), and mass flux (120 and 220 kg/m2.s). Results showed that the heat transfer coefficient depends strongly on the operating parameters. It is augmented as the wall heat flux and the saturation temperature are raised. A dryout region appears for all refrigerants at vapor quality ranging between 0.7564 and 0.8824. Furthermore, from a heat transfer point of view, R290 and R600a are better than R134a.

Investigation of Heat Transfer and Pressure Drop for R744 in a Horizontal Smooth Tube of R744/R404A Hybrid Cascade Refrigeration System—Part 2: Low-Temperature Region

This paper studies the evaporative heat transfer characteristics of R744 at low temperatures in a horizontal smooth tube as a cascade refrigeration system (CRS) among hybrid cascade refrigeration systems (HCRSs). There is a lack of research on the low-temperature evaporative heat transfer characteristics of R744 under the operating conditions of evaporators used in actual CRSs used in supermarkets. Therefore, this study aims to provide basic data on the evaporative heat transfer characteristics of R744 in the evaporators of refrigerators used in supermarkets. The tube used in the evaporation experiment conducted herein was a smooth horizontal copper tube with an inner diameter and length of 11.46 mm and 8000 mm, respectively. The experimental parameters were as follows: heat fluxes of 11.8–21.3 kW/m2, mass fluxes of 76.3–175.1 kg/(m2·s), and saturation temperatures of −49.8–−30.2 °C. The main results are summarized as follows: the evaporative heat transfer coefficient of R744 can be predicted well by using the correlation formula of Chen at the evaporation temperature of −40 °C in the CRS.

Flow boiling heat transfer characteristics over horizontal smooth and microfin tubes: An empirical investigation utilizing R407c

The flow boiling heat transfer performance of horizontal smooth and microfin tubes was investigated using the refrigerant R407c. The evaporator test tube contains an outside, inner diameter and length of 9.52, 8.52, and 1000 mm, respectively. The investigations were performed out at 283.15 and 303.15 K saturation temperatures with hot water circulation heat flux of 75 kW.m-2, refrigerant heat flux varying from 5 to 85 kW.m-2, and mass flux varied from 15 to 250 kg.m-2.s-1, keeping the area ratio of microfin tube 1.68%. The experimental results are compared to several previously recognised correlations. Experimental outcomes demonstrated that the heat transfer rate of the microfin tube is superior to the smooth tube. The percentage of heat transfer enhancement was considered to exceed in microfin tube by 28–280%. The pressure drop in regard to R407c was found to be augmented than smooth tube according to the experimental results and enhancement was achieved in microfin tube by 68–110%. Finally, a sensitivity analysis is carried out in flow boiling heat transfer phenomenon via the smooth tube.