Flow Heat Exchanger Research Articles

Process Considerations for the Production of Hydrogen via Steam Reforming of Oxygenated Gases from Biomass Pyrolysis and Other Conversion Processes

AbstractIn 2021, average CO2 emissions was 9.7 g CO2/g H2 produced, primarily based on steam methane reforming (SMR) technology that currently dominates hydrogen production. The substitution of natural gas (NG) and other fossil feedstocks in SMRs with renewable gases may be considered as an option for reducing greenhouse gas emissions. This analysis explores process impacts and constraints associated with the potential introduction of biogenic gases into SMRs. The results indicate that replacing NG in the fuel train of the SMR, followed by partial replacement of NG in the feed train may be a feasible approach. For the CO‐ and CO2‐rich gas compositions assumed in this analysis the results indicate that feed train may accommodate up to 25 mole % of biogenic gases using allowances in existing designs and/or with small modifications, while maintaining similar hydrogen output. NG substitution in higher proportions require more major changes because of increased flow rates and heat exchange requirements in the system. Biogenic gases with lower CO2 and higher calorific values are advantageous for NG substitution, and dry reforming using the CO2 present in the feed gas can reduce steam consumption and increase process efficiency within limits where coking does not become a new constraint.

Computational investigation of cross flow heat exchanger: A study for performance enhancement using spherical dimples on fin surface

Performance improvement of a heat exchanger is a vast topic for research work right now. This paper presents a numerical analysis of cross flow heat exchanger using CFD software package ANSYS FLUENT. To improve the performance of a traditional smooth fined heat exchanger, dimples are used on the fin surfaces. A cross flow heat exchanger with spherical dimples on the surfaces of the fins was modelled and effect of dimples on the performance of the heat exchanger was numerically investigated. Numerical investigations were carried out for different dimple depths such as 3 mm, 4 mm, 5 mm, 5.5 mm dimples on different positions such as on one side, on both side; and different number of dimples such as 32, 26, 20. Boundary conditions were considered as constant tube outer surface temperature, Reynolds number of 3553, inlet air temperature Ti = 299.45 K. Considering balance between heat transfer enhancement and pressure drop, performance evaluation criterion (PEC) was estimated to observe the optimal result. PEC value greater than 1 means there is better performance in consideration of both heat transfer rate and frictional loss. The case of 26 dimples on both sides of fin with 5.5 mm dimple depth provides highest 7.33 % increases of Nusselt number compared to smooth fin. The maximum PEC value 1.034 was found for the case of 32 dimples on both side of fin with 3 mm dimple depth. From the PEC analysis, it was observed that the case of 32 dimples on both sides of the fin with 3 mm dimple depth is the optimum case among all other cases with 5.71 % higher Nu and 6.75 % higher friction factor than smooth fin. To compare the heat exchanger performance, temperature effectiveness has also been evaluated. The case of 32 dimples and 26 dimples on both side of fin with 5.5 mm dimple depth have same and highest value of temperature effectiveness which is 11.45 %, where that value for smooth fin is 10.16 %. Furthermore, the results have been analyzed with the variation of Reynolds numbers.

Experimental and numerical investigation of thermo-hydrodynamic performance of twin tube counter flow heat exchanger using cerium oxide nanofluid

This study accomplished experimental and numerical investigations regarding cerium oxide (CeO2) nanofluid. The aim of this study is to estimate the thermo-hydrodynamic performance of twin tube counter flow heat exchangers (TTCFHEs) in the presence of CeO2 nanofluid. The CeO2 nanofluid concentrations varied from 0.1% to 0.3% by volume. In TTCFHEs, the mass flow rates of cold fluid flow varied from 3 LPM to 15 LPM (i.e. Reynolds number, Re varied from 2436 to 11,626). At the same time, hot fluid flows inside the shell at a constant mass flow rate of 6 LPM. For the numerical investigations, the standard k-ɛ model is adopted for the turbulent flow regimes, where the Reynolds number is varied from 2436 to 11,626. For validation purpose, the present numerical study and experimental data are matched with the correlations available in the literature. Further, numerical result of the Nusslet number is well agreed with the experimentally recorded data with a deviation less than 10%. From the study, it is witnessed that the outlet temperature of the cold fluid increases and decreases with increasing the concentrations of CeO2 nanofluids and with increasing the flow Reynolds number, respectively. On account of 0.3% and 0.2% CeO2 nanofluid, the average Nusselt number (Nu) showed almost 43.35% and 30.13% greater than that of base fluid with a moderate increase in the pressure drop in the range of mass flow rate is considered. However, from the numerical investigations, the performance evaluation criteria (PEC) increases with increasing nanofluid concentrations. At higher concentrations (i.e. 0.3%) of CeO2 nanofluid, the average PEC showed 16.65% higher than the 0.1% CeO2 nanofluid with a marginal increase in the pressure drop.

Experimental and Numerical Analysis of the Efficacy of a Real Downhole Heat Exchanger

In this paper, a three-dimensional (3D) numerical model based on the finite element method (FEM) is developed to determine the fluid flow and heat transfer phenomena in a real multi-tube downhole heat exchanger (DHE), designed ad hoc for the present application, considering natural convection inside a geothermal reservoir. The DHE has been effectively installed and tested on the island of Ischia, in southern Italy, and the measurements have been used to validate the model. In particular, the authors analyze experimentally and numerically the behavior of the DHE based on the outlet temperature of the working fluid, thermal power, overall heat transfer coefficient, and efficiency. Furthermore, the influence of the degree of salinity on the performance of the DHE has been studied, observing that it degrades with the increase in the degree of salinity. The results show that the DHE allows to exchange more than 40 kW with the ground, obtaining overall heat transfer coefficient values larger than 450 W/m2 K. At the degree of salinity of 180 ppt, a decrease in the efficiency of the DHE of more than 8% is observed.

Thermal evaluation of MHD boundary‐layer flow of hybridity nanofluid via a 3D sinusoidal cylinder

AbstractThe study of the boundary layer is considered one of the most important theories in the field of heat and mass transfer because of its important explanation that shows us the behavior of different surfaces while they are under the influence of the flow accompanied by different thermal forces. The study of corrugated surfaces is one of the engineering applications, such as flow in heat exchangers or solar cells or cooling processes during surface heat treatments. This model is also used in medical applications such as flow in arteries or movement in the intestines. So, the work deals with investigating the boundary layer surrounding a three‐dimensional sinusoidal pipe; the boundary layer was assumed to be filled with a hybrid nanofluid consisting of water +Cu nanoparticles as the main fluid, supported by a small concentration of Al2O3 or Ag nanoparticles. The boundary layer is described by a set of nonlinear partial differential equations due to the continuity, momentum, and energy equations, which are transformed into a set of dependently coupled nonlinear ordinary differential equations. The obtained system of equations was solved using numerical techniques. The behavior of the boundary layer under the varying types and concentrations of nanoparticles and the influence of the magnetic field has been depicted by a set of graphs and tables. With reference to some results, it is found that using 5% of nanoparticles of aluminum oxide raises the rate of cooling by 8% and using 5% of silver nanoparticles increases it by 5%.

Innovative concept of splitting water flow rate of cross flow heat exchangers as a solution for reduction of non-uniformity effect – Thermal modelling and feasibility analysis

The water flow rate of water-air cross-flow Heat Exchangers (HXs) is split into various smaller flow rates in this research work, which circulates into several smaller HXs that are put together. In fact, as the non-uniformities in the airflow velocity distributions increase, the thermal performance declines. These non-uniformities, especially in automotive applications, are represented by velocity magnitudes on a part of the HX front area and zero velocities on the remaining part. The innovative idea and the originality of the present study consists on dividing the water flow rates into various passageways as they reach a water-flow HX, where each passage is associated with several smaller HXs. In relation to the air flow, the smaller HXs are sequentially combined. The advantage of such splitting leads to keeping parts of the area of the initial HX from being subjected to low convection heat transfer with zero or negligible velocities and subsequently allows for an increase in the thermal performance globally. Moreover, the dividing idea enables faster but hotter airflow to be applied to each of the individual HXs. Computations for double-split HX utilizing a developed computational code are used to demonstrate the viability of this design. A traditional cross-flow water-air HX's thermal performance can be improved by up to 26.2 % using the novel idea, it has been demonstrated.

THE EFFECT OF USE OF DIFFERENT DIAMETER ON IMPROVEMENT OF FLOW AND HEAT TRANSFER IN TUBE BANK HEAT EXCHANGERS

Boru demeti ısı değiştiricilerinde, boruların içindeki akışkana çapraz yönde etrafından geçirilen başka bir akışkan ile ısı transferi gerçekleştirilir. Boru dışından çapraz yönde geçirilen akışkan çoğunlukla gaz akışkanlardır. Art arda yerleştirilen borularda, en fazla ısı transferi çoğu kez birinci boruda elde edilmektedir. Birinci borudan sonra ısı ve akış karakteristiği birbirine benzer hal almaktadır. Bu durumda, hız ve sıcaklık konturlarının tekrarlanması ile periyodik akış elde edilmiş olur. Ardışık olarak gelen borularda sınır tabakanın sürekli olarak yenilenmesini sağlamak, diğer borularda birinci borudaki gibi yüksek ısı transferi elde edilmesine imkân tanıyacaktır. Isı transferi iyileştirilirken en önemli sorun basınç düşümünün de artmasıdır. Bu çalışmada düzgün sıralı dizilişe sahip boru demetinde, art arda yerleştirilen dört farklı çaptaki borular kullanılarak, ısı transferinin arttırılması ve basınç düşümünün azaltılması amaçlarıyla sayısal optimizasyon yapılmıştır. Karşılaştırmalar, ısı transferi yüzey alanının sabit, borular arasındaki boyuna ve enine mesafelerin aynı olduğu varsayılarak yapılmıştır. Düzgün sıralı dizilişe sahip boru demetinde ardışık olarak yerleştirilen dört adet borunun çaplarının D_1=5 mm,D_2=15 mm,D_3=6 mm,D_4=14 mm olması durumunda ısı transferi %14.5 oranında artarken, basınç düşümü de %377 oranında artmıştır.

Morphing optimization of flow and heat transfer in concentric tube heat exchangers

Concentric tube heat exchangers are vital in various industrial applications, including chemical, process, energy, mechanical, and aeronautical engineering. Advancements in heat transfer efficiency present a significant challenge in contemporary research and development. This study concerns optimizing flow and heat transfer in concentric tube heat exchangers by morphing the tube's walls. The adjoint shape optimization approach is implemented in a fully turbulent flow regime. The effect of inner tube deformation on flow physics and heat transfer is examined. The results show that morphing can lead to a 54% increase in the heat transfer rate and a 47% improvement in the overall heat transfer coefficient compared to straight concentric tube designs. Moreover, the thermal-hydraulic performance factor is calculated to account for the relative increase in heat transfer when the optimal and initial designs are operated under the same pumping power. A thermal-hydraulic performance factor of 1.2 is obtained for the new design, showing that the heat transfer enhancement caused by morphing the tube's walls outweighs the increase in pumping power. The physics of a radial flow, resulting from an adverse pressure gradient in an annular region caused by the successive inner tube deformation, significantly augments heat transfer. This study shows morphing can lead to higher thermal efficiencies, and numerical optimization can assist in achieving this goal.

Investigation of Outdoor Air Temperature Effects on Heat Recovery in Cross Flow Heat Exchanger

A heat recovery device was designed and manufactured to provide air-to-air heat transfer by using a cross-flow heat exchanger on the pipe bundles. For this purpose, different cold air inlet temperature values and the temperature values of high temperature hot exhaust gases in the tube bundle heat exchanger were determined as operating parameters. According to the temperature increase of the cold air entering the heat exchanger; The kinematic viscosity values of the air increased and the maximum Reynolds number in the flow state of the air passing through the test heat exchanger was decreased. The average Nusselt numbers and average air convection coefficients in the flow of air decreased according to the temperature increase of the cold air. According to the temperature increase of the cold air entering the heat exchanger, both the analytical and experimental outlet temperature values of the cold air leaving the heat exchanger increase very close to each other. With this increase, the amount of heat transferred from the fluid to the fluid in the heat exchanger decreases. While the temperature value of the cold air entering the heat exchanger increases, the temperature difference value of the advancing air from the beginning to the outlet (ΔT= Ts – Ti) decreases. Due to this decrease, a decrease was observed in the amount of heat transfer.

Assessment of flow and heat transfer of triply periodic minimal surface based heat exchangers

An efficient intermediate heat exchanger is crucial for ensuring the safe operation, lifespan and energy efficiency of the advanced nuclear systems. Benefiting from the development of additive manufacturing technology, it is possible to design and optimize heat exchangers by introducing triply periodic minimal surface (TPMS) structures. With the excellent mechanical and thermal performance of TPMS, further improvements in the energy efficiency of advanced nuclear systems are achievable. In this study, I-WP surface, Primitive surface based heat exchangers and a printed circuit heat exchanger for accelerator driven subcritical systems are constructed in three dimensions. In order to obtain the potential enhancement of thermal performance of TPMS-based heat exchangers, the fluid flow and conjugate heat transfer characteristics in TPMS heat exchangers, especially for the specific working medium of lead-bismuth eutectic (LBE) are investigated. A parametric analysis is conducted on the key design variables including the solid volume fraction and hydraulic diameter. The results indicate that TPMS-based heat exchangers could achieve about 2–3 times the total heat transfer rate with half the volume of a printed circuit heat exchanger. The TPMS topologies contribute greater heat transfer enhancement on the Helium side than the LBE side, which helps to optimize the thermal resistance allocation in Helium-LBE heat exchangers. An increase of solid volume fraction enhances the convective heat transfer of Helium in I-WP heat exchanger, while homogenizing the local thermal performance. This study provides a database for the design and optimization of TPMS-based heat exchangers, which contributes to the sustainable future target.

Simulation of Fluid Flow and Heat Transfer Process in Heat Exchangers in Petroleum Industries

Heat exchangers are very useful equipment in a wide range of industries, therefore ?the analysis of the internal flow in them is very important. In this study, a heat exchanger is modeled to solve the flow and temperature field. Three ?turbulence models have been tested for first and second order discretization using ?two different mesh densities, and the results are as follows. The effects of different parameters on the internal conditions of the converter have ?been simulated. The temperature changes decrease in proportion to the reduction of ?the heat transfer coefficient in viscous fluids, and the Reynolds number is greater ?than the Parantel number. For the tube with constant wall temperature and shell inlet, the heat transfer ?coefficient, pressure drop values and heat transfer rate are obtained. In another part, it is shown that the stabilization time of the fluid temperature has a ?direct relationship with the heat capacity of the pipes, and that the performance of ?the tubular heat exchanger with spiral walls is better than that of segmental walls. The intermittent temperature input has been investigated. It has been shown that ?the other flux will fluctuate with the same frequency, which it also proved our ? theoretical results.

Influence of PST and PHF heating conditions on the swirl flow of Al+Mg+TiO2 ternary hybrid water-ethylene glycol based nanofluid with a rotating cone

Swirl flow heat exchangers are commonly used in industrial processes such as power generation, chemical processing, and refrigeration. They can be used for both heating and cooling applications and can be designed to handle a wide range of fluid flow rates and temperatures. This study investigated the influence of PST (prescribed surface temperature) and PHF (prescribed heat flux) heating conditions on the swirl flow of Al+Mg+TiO2 ternary hybrid water-ethylene glycol (50/50) based nanofluid with a heated rotating cone. The governing ordinary differential equations were derived from the partial differential equations using the proper similarity transformations. The problem was solved using the Shifted Legendre Collocation Method (SLCM), which is a powerful numerical method. The results showed that the PST heating conditions had a significant impact on the flow and heat transfer characteristics of the ternary hybrid nanofluid. Under PHF heating conditions, the swirl velocity distribution was leading to a noteworthy influence. The use of the Al+Mg+TiO2 ternary hybrid water-ethylene glycol based nanofluid resulted in a significant enhancement in the convective heat transfer coefficient. The SLCM method provided accurate and efficient numerical solutions for the problem, demonstrating its suitability for simulating complex fluid flow and heat transfer problems.

Pressure drop characterization on cryogenic multiphase flow in spiral wounded heat exchanger under high mass flow conditions

In order to clarify the influence of dryness, working medium and mass flow rate on pressure drop characteristics in shell side of spiral wound heat exchanger, a simplified test section has been analyzed in this study. The model is with a coiled section under compact design: 1 mm layer spacing of and 2 mm tube spacing in the main structure. The mixed alkane composed of methane, ethane, propane and others are used as working fluid. The current study is focused on the pressure drop behaviors and the effects of multiphase flow in different stages of cooling process in the cryogenic heat exchanger. Systematic numerical model has been established in this study to investigate the pressure behaviors, which are also verified against newly constructed experimental system. Operating conditions range from vapor quality of 0.1–0.9, mass flux of 60–120 kg·(m2·s)−1, under the operation pressure of 0.25 MPa and temperature from −27 °C to −170.6 °C. The absolute error of pressure measurement is less than 1.5 kPa and the absolute error of pressure drop measurement is less than 25 Pa, and the relative error is 0.25 % for the current test. The experimental results show that the friction pressure drop increases with the increase of vapor quality from 0.1 to 0.9 and mass flux from 60 to 120 kg·(m2·s)−1, and the growth gradient of friction pressure drop decreases with the increase of vapor quality. A set of pressure drop correlation has been established to reflect the influence of factors such as vapor quality and mass flow rate, and the deviation between predicted pressure drop and experimental data was within ±20 %.

Numerical and empirical simulation of fluid flow in a spiral plate heat exchanger with Nusselt number correlation development

Numerical and empirical simulation of fluid flow in a spiral plate heat exchanger with Nusselt number correlation development

Modelling of thermo-hydraulic behavior of a helical heat exchanger using machine learning model and fire hawk optimizer

The study of the fluid flow in heat exchangers and its related mass and heat transfer processes is a very complicated research subject. Modeling of coupled fluid flow and heat transfer processes using numerical and analytical approaches are cumbersome problems. Hence, the current study investigates the modeling thermo-hydraulic behavior of a helical plate heat exchanger (HPHE) using advanced machine learning models. The outlet temperatures of hot and cold fluids are predicted considering different cross-sectional areas and pitches of the flow channels. This paper fulfills the research gap about fluid flow and heat transfer mechanisms by considering advanced machine learning approaches. The proposed model helps different manufacturers of heat exchangers to estimate the thermal performance and characteristics. The developed model aims to provide an advanced random vector functional link (RVFL) optimized fire hawk optimizer to predict outlet temperatures of working fluids of HPHE. The proposed model was compared with four optimized models using grey wolf, jellyfish, sine-cosine, and hybrid salp swarm-whale optimizers. The results of all models were compared and fire hawk optimizers showed superior accuracy compared with other models. Fire hawk optimizer had the highest R2 (0.999) followed by jellyfish (0.998) for both investigated responses. Hybrid salp swarm-whale and sine-cosine optimizers had the lowest R2 (0.987) in the case of hot fluid.

Evaluating two-phase fluid flow and heat transfer in pillow-plate heat exchangers with nanofluids for organic Rankine cycle in municipal solid waste power plant: A numerical simulation study

One of the key considerations in the design and operation of process industries nowadays is reducing energy waste. The purpose of this research is to assess fluid flow and heat transfer in pillow-plate heat exchangers (PPHEs) using nanofluids for the Organic Rankine Cycle (ORC) in Municipal Solid Waste (MSW) power plants. The thermal performance and hydraulic features of the PPHE were investigated using a two-phase numerical modeling approach. three nanoparticles of Cu, TiO2, and Al2O3 were examined. To precisely determine the temperature distribution within the heat exchanger, various boundary conditions were used. The results demonstrate a strong correlation between the velocity field and temperature, underlining the importance of boundary conditions in determining the temperature profile. Furthermore, the two-phase model illustrates that nanofluids are extremely reliant on inlet velocity and volume fraction. such that at a 2 m/s inlet velocity, increasing the volume percentage to 12.8% contributes to heat transfer coefficient improvements of 7.57%, 12.15%, and 2.71% for water_TiO2, water_Al2O3, and water_Cu, respectively. These findings give significant insight into the fluid flow and heat transfer properties of PPHEs, as well as prospective pathways for increasing thermal performance and decreasing pump power in ORC systems using nanofluids in MSW-generating plants.

Experimental analysis of heat exchanger using perforated conical rings, twisted tape inserts and CuO/H2O nanofluids

This research paper presents an experimental analysis on a heat exchanger tube using a newly designed perforated conical ring combined with twisted tape as inserts. The investigation analyzes various geometric and flow parameters in the experimental setup, including a wide range of Reynolds numbers, varying from 6000 to 30000, nanoparticle volume concentration (φnp) of 0.25-1.0%, the ratio of inlet flow dia to inner print dia of the ring (DIR/DBR) of 1.33-2.33, ring pitch ratio (RP/ DED) of 1.41-2.51, twist ratio (TL/ WT) of 3.33-4.38, with fixed values for other parameters: relative ring height ((DED/ WR) of 2.33 and nanoparticle diameter (dnp) of 30 nm. The optimal result of the thermal-hydraulic performance parameter (ηTT) is 1.45 at DIR/DBR = 1.83, TL/ WT = 3.50 and RP/ DED = 1.76. For the CuO/H2O nanofluids flow heat exchanger tube with perforated conical rings, empirical correlations were developed for the Nusselt number and the friction factor. These correlations were established with a range of 9.0% and 8.0%, respectively.

Exploring a novel route for low-grade heat harvesting: Electrochemical Brayton cycle

Efficient technologies to convert huge amounts of low-grade heat to power are urgently desired. Although various electrochemical technologies have been proposed, the low thermal efficiency and power density still limit their practical applications. Starting from the ideal cycle of thermo-chemical engines and the decoupling of heat transfer and charge transport, this study proposes the electrochemical Brayton cycle (EBC) for power generation for the first time, which is realized by flow batteries and heat exchangers. By establishing energy and entropy generation models, the thermal efficiency and power density of ideal and actual EBC systems, as well as the isentropic efficiency and entropy generation are analyzed and discussed. The results indicate the ideal EBC without overpotential performs a maximum power density of 690 W m−2 and a relative efficiency to Carnot efficiency of 52.3% when operated between 25 and 75 °C. With 70% heat regeneration, the relative efficiency and power density of actual EBC could reach 45.3% and 1.6 W m−2 at an electrolyte flow velocity of 0.01 mm s−1, or 23.7% and 6.8 W m−2 at a velocity of 0.1 mm s−1, respectively. Further entropy generation analysis reveals that the main contributors to entropy generation are heat transfer, activation overpotential and ohmic overpotential in order of magnitude. Furthermore, the high efficiency of EBC compared with other technologies, its broad application space, especially its advantages of integration with energy storage indicate its feasibility and potential.

A thermo-hydro-mechanical model to evaluate the seismic properties of geothermal reservoirs

Fractured-vuggy thermal reservoirs with complex pore spaces (stiff pores, cracks, and fractures) are typical geothermal resources for development and utilization in China. The cyclic recovery of such thermal reservoirs involves a complex thermo-hydro-mechanical (THM) coupling process. Insights into the thermoelastic effects of heating-cooling cycles on the seismic response have great potential for seismic monitoring in the cyclic recovery, which remains largely unaddressed in the literature. We intend to fill this gap by applying the double-porosity thermoelasticity theory to interpret ultrasonic measurements on granite under water-cooling conditions. We consider an isotropic porous host embedded with fractures. A plane-wave analysis yields the classical P and S waves and three slow P waves, namely the slow (Biot) P1, the slow (Biot) P2, and a thermal P. We investigate the combined effect of temperature, porous structure, and pore fluid on the thermoelastic properties of the THM process for typical granite reservoirs that experience a cold-shock process. Fractures provide the main channels for heat exchange and fluid flow. Our THM thermoelastic model describes the reservoir properties as a function of temperature associated with thermal-induced cracking, where fracture porosity is more important than the stiff (host) pore to describe the reservoir quality. We find that the thermal conductivity and specific heat have negligible effects in the seismic frequency band for the temperature range of less than 400°C, whereas the crack density significantly affects the seismic response in the heating-cooling cycles because of the additional contribution of thermal- and cold-shock-induced cracks. We further determine that the P-wave velocity and attenuation due to thermal effects under water cooling offer an important index to monitor the thermal-induced cracking and operation efficiency of the enhanced geothermal system. The THM thermoelastic model lays the foundation for active (or passive) seismic monitoring of the cyclic recovery of thermal reservoirs.

Using the Log Mean Temperature Difference (LMTD) and ε-NTU Methods to Analyze Heat and Mass Transfer in Direct Contact Membrane Distillation.

In direct contact membrane distillation (DCMD), heat and mass transfers occur through the porous membrane. Any model developed for the DCMD process should therefore be able to describe the mass transport mechanism through the membrane, the temperature and concentration effects on the surface of the membrane, the permeate flux, and the selectivity of the membrane. In the present study, we developed a predictive mathematical model based on a counter flow heat exchanger analogy for the DCMD process. Two methods were used to analyze the water permeate flux across one hydrophobic membrane layer, namely the log mean temperature difference (LMTD) and the effectiveness-NTU methods. The set of equations was derived in a manner analogous to that employed for heat exchanger systems. The obtained results showed that the permeate flux increases by a factor of approximately 220% when increasing the log mean temperature difference by a factor of 80% or increasing the number of transfer units by a factor of 3%. A good level of agreement between this theoretical model and the experimental data at various feed temperatures confirmed that the model accurately predicts the permeate flux values for the DCMD process.