High Heat Transfer Efficiency Research Articles

Experimental investigation on interface characteristics and heat transfer during bubble condensation in narrow rectangular channel

Direct steam contact condensation in subcooled water is widely used in various industries because of high efficiency in heat and mass transfer. A visual experimental is carried out to investigate the condensation process of single vapor bubble in narrow rectangular channel by a high-speed camera. Steam mass flux and water temperature are 0–1000 kg/(m2·s) and 57–93 °C, respectively. Four different condensation patterns are found in this study, such as chugging, ellipsoidal jetting, smooth grown bubble and rough grown bubble based on bubble behavior and surface feature. The bubble condensation period is positively correlated with initial bubble diameter. The bubble interface is smooth at low mass flow rates, while it becomes rough when the mass flow rate is high and the process of condensation is shorter. There is a bubble critical diameter during growth stage and each type of bubble will have distinctive phenomena when it reaches the critical diameter. The restriction of the narrow rectangular channel on vapor bubble is that an accelerated condensation process occurs when the bubble diameter changes from restricted to unrestricted. The factor of heat conduction is taken into account in the energy conservation equation, and the condensation heat transfer model is proposed. By deriving the energy conservation equation, a dimensionless parameter A related to the thermal conductivity of the wall and the width of flow channel is obtained. A predictive correlation for bubble diameter and a condensation Nusselt correlation are proposed, and the new correlations incorporate the dimensionless parameter A.

Temperature dependence of dielectric properties of blood at 10 Hz-100 MHz.

The temperature dependence of the dielectric properties of blood is important for studying the biological effects of electromagnetic fields, electromagnetic protection, disease diagnosis, and treatment. However, owing to the limitations of measurement methods, there are still some uncertainties regarding the temperature characteristics of the dielectric properties of blood at low and medium frequencies. In this study, we designed a composite impedance measurement box with high heat transfer efficiency that allowed for a four/two-electrode measurement method. Four-electrode measurements were carried out at 10 Hz-1 MHz to overcome the influence of electrode polarization, and two-electrode measurements were carried out at 100 Hz-100MHz to avoid the influence of distribution parameters, and the data was integrated to achieve dielectric measurements at 10 Hz-100MHz. At the same time, the temperature of fresh blood from rabbits was controlled at 17-39°C in combination with a temperature-controlled water sink. The results showed that the temperature coefficient for the real part of the resistivity of blood remained constant from 10Hz to 100kHz (-2.42%/°C) and then gradually decreased to -0.26%/°C. The temperature coefficient of the imaginary part was positive and bimodal from 6.31kHz to 100MHz, with peaks of 5.22%/°C and 4.14%/°C at 126kHz and 39.8 MHz, respectively. Finally, a third-order function model was developed to describe the dielectric spectra at these temperatures, in which the resistivity parameter in each dispersion zone decreased linearly with temperature and each characteristic frequency increased linearly with temperature. The model could estimate the dielectric properties at any frequency and temperature in this range, and the maximum error was less than 1.39%, thus laying the foundation for subsequent studies.

Investigation of Flow and Heat Transfer Performance of Double-Layer Pin-Fin Manifold Microchannel Heat Sinks

The manifold microchannel (MMC) heat sink is characterized by high heat transfer efficiency, high compactness, and low flow resistance. It can be an effective method for the high-flux removal of high-power electronic components. To further enhance the performance of the MMC, a double-layer pin–fin MMC structure was designed. The thermodynamic properties, including the flow and heat transfer characteristics, were numerically investigated using ANSYS Fluent with deionized water as the working liquid. Compared with the single-layer MMC, the temperature uniformity is better, the pressure drop is lower, and the comprehensive performance is improved at the cost of slightly larger thermal resistance for the double-layer MMC. The geometric effects on the thermodynamic performance were also analyzed. The results show that among the pin–fin structures with round, diamond-shaped, and rectangular cross-sections, the round pin–fins demonstrate the best comprehensive performance and the minimal thermal resistance. Under the same inlet velocity, the thermal resistance is decreased, and the comprehensive performance is first increased and then decreased as the pin–fin size increases. In addition, it is recommended to adopt a larger height ratio for low inlet velocity and a smaller height ratio for high inlet velocity.

Fuel cooling technology based on efficient heat dissipation

Aiming at the thermal management of new aviation equipment and taking typical aircraft as the specific application background in this paper, the dynamic management technology of fuel heat sink based on high efficiency heat exchange technology is studied, the heat dissipation demand of aircraft is carded, and several heat dissipation schemes are designed. Then, the paper makes a quantitative evaluation of each scheme by means of simulation, compares the concrete advantages and disadvantages of each scheme, clarifies the key parameters, and considers the possibility of installing a certain machine. Through the research, the feasibility of the application of high efficiency heat transfer technology in new aeronautical equipment is preliminarily verified, which provides a possible technical approach for the integrated heat management of aircraft in the future.

Heat Transfer Enhancement of Regenerative Cooling Channel with Pyramid Lattice Sandwich Structures

To meet the requirements of high heat transfer efficiency and light weight, the pyramid lattice structures are applied to the regenerative cooling design of scramjets. This study numerically investigates heat transfer and fluid flow characteristics of kerosene in a regenerative channel with pyramid lattice sandwich structures. At the same porosity, the maximum wall temperature of the pyramid lattice sandwich regenerative cooling channel decreases by 30%. With increased porosity, the cooling capacity of the pyramid regenerative cooling channel decreases gradually. The numerical results show that a complex secondary flow appears in the flow field in the pyramid lattice structures. In the downstream region of each strut, a spiral vortex is formed which accelerates the flow velocity approaching the wall with heat transfer enhancement. Because of the disturbing effect of the strut, a high turbulent kinetic energy region is formed in the upstream region of each strut and the heat transfer is enhanced. In general, the local heat transfer in the upstream region of the pyramid strut is better than that in the downstream region. For pyramid lattice structures, the cooling structures with high convective heat transfer and relatively low pressure drop can be obtained by optimization of the design parameters.

Multi-objective optimization of printed circuit heat exchanger used for hydrogen cooler by exergoeconomic method

Hydrogen cooler is a key equipment of the precooling unit in hydrogen refueling stations with the requirement of high heat transfer efficiency, high compactness and high pressure resistance. Printed circuit heat exchanger is a promising candidate for the hydrogen cooler due to its great performance on extremely high pressure and high temperature working environment. In this paper, a hydrogen cooler with a thermal load of 72 kW is firstly designed by using the segmented thermal design method and logarithmic mean temperature difference method. Then, the capital model of the hydrogen cooler is established to evaluate the performance using the exergoeconomic method. The results show that the operating cost, which is related to exergy destruction, accounts for 94.5% of the total cost of the hydrogen cooler. The thermal exergy destruction accounts for 92.4% of the total exergy destruction. Finally, the geometrical parameters of the channel are optimized by using the multi-objective optimization. The channel radius shows the most significant impact on the construction cost and operating cost among the three geometrical parameters. Compared with the coaxial tube evaporators, the printed circuit heat exchanger has better performance on the volume and total cost, which are reduced by 88.0% and 4.0% respectively.

Experimental investigation on thermal management of proton exchange membrane fuel cell stack using micro heat pipe array

• A new PEMFC thermal management method based on MHPA is proposed. • MHPA reduces the temperature of air-cooled PEMFC and improves the internal temperature uniformity. • MHPA realizes the separation of PEMFC reaction air and cooling air, and strengthens the heat dissipation. As a result of the limited air cooling capacity, the heat dissipation problem of air-cooled proton exchange membrane fuel cells (PEMFC) may limit the increase in power generation. In this research, the high-efficiency heat transfer element micro heat pipe array (MHPA) is integrated into the bipolar plate, and it is applied to the thermal management of PEMFC to realize the separation of reaction air and cooling air. A MHPA-PEMFC comprising 50 single cells is designed, and a series of comparative experimental studies are conducted. Results show that MHPA effectively improves the temperature distribution inside PEMFC. Compared with traditional PEMFC, the average temperature, maximum temperature difference, and maximum Index of Uniform Temperature of MHPA-PEMFC are reduced by 11.58 °C, 5.10 °C and 0.97 °C, respectively. When the reaction air flow rate is 160.8 m 3 /h, the maximum output power is 197.3 W higher, and the mass power density and volume power density are increased by 12.2% and 9.5%, respectively. The heat dissipation of MHPA’s cooling channel can account for up to 50.5% of the theoretical heat production, but the proportion decreases with the increase in reaction air flow. The results provided a basis for the application of MHPA to PEMFC thermal management.

Study on the three-dimensional heat flow field of supercritical nitrogen in a micro-channel plate heat exchanger

Micro-channel plate heat exchanger (MCPHE) has been recognized as a new high-efficiency heat transfer device and widely utilized in the energy field due to its compactness and high heat exchange rate. In this paper, the three-dimensional heat flow field of supercritical nitrogen (SCN2) in a simplified MCPHE is numerically simulated using computational fluid dynamics (CFD) simulation technology. The numerical approach predicts the thermo-hydraulic performance of SCN2 with a relatively good accuracy, by comparing with the published experimental data. Furthermore, the effects of pressure (3.6 ∼ 7 MPa) and mass flux (800 ∼ 1200 kg/(m2∙s)) on the convective heat transfer characteristics of SCN2 are thoroughly examined, especially the heat flow field of SCN2 in different circumferential directions of the micro-channel is revealed. The obtained results show that under the condition of low pressure and high mass flux, the maximum circumferential inner wall temperature appears at 90° of the micro-channel at the same axial position. With an increased mass flux, the maximum inner wall temperature and minimum heat transfer coefficient gradually shifts from 180° to 90°. When the buoyancy coefficient Gr*/Re2 > 1, the buoyancy force is conducive to enhance the fluid heat transfer capacity gathered at the bottom of the micro-channel. Meanwhile, the buoyancy force could make the distribution of thermo-physical properties of SCN2 uneven at the same time. Finally, in view of the obtained data, a new dimensionless correlation is proposed to predict the convective heat transfer process of SCN2 inside MCPHE, and the prediction error is less than 20%. The research outcomes could provide a reference for the optimal design and safe operation of MCPHE.

Numerical study on structure optimization and heat transfer characteristic of distributed pulsating flow heat exchanger

ABSTRACT Distributed pulsating flow planar tube bundle heat exchanger (DPFPTB-HE) can improve heat transfer and have a high prospect of application in the industry. Computational fluid dynamics (CFD) software Fluent was utilized as an analysis tool, and the factors affecting heat transfer in heat exchangers were comprehensively studied based on the theory of fluid mechanics and heat transfer in this article. The local average surface Nusselt number(Nu v) evaluated the heat transfer performance. Results found that the DPFPTB-HE proposed in this paper has more uniform distribution of cold fluid in the shell domain and higher heat transfer efficiency in each layer of the tube bundle compared with the conventional planar tube bundle heat exchanger (PTB-HE). In this paper’s single-factor analysis experimental session, the study showed that with the inlet velocity increases, Nu v increases; as the length of the branch pipe increases, Nu v decreases; branch pipe diameter increases, Nu v decreases. The results obtained Nu v by applying the optimal experimental parameters selected by the Taguchi method were 7.22% larger than the maximum value in the control group. The numerical result and methodology are beneficial for providing further insight into guiding the optimization of heat exchanger structure and promoting industrial progress.

3D topology optimisation of liquid-cooled microchannel heat sinks

• Thorough numerical analysis of novel method for designing heat sink geometries. • Full 3D topology optimisation outperforms equivalent 2D topology optimisation. • Enhancement likely due to improved vertical and spanwise mixing within channel. • Smoothing and simplification of the heat sink design are performed and discussed. • Results useful for industrial/academic developers of heat sinks via AM techniques. A full 3D topology optimisation is conducted in COMSOL to develop fin structures for a heat sink. Nine topologies are generated, and then imported into FLUENT for numerical testing. To permit fabrication, the geometries were smoothed, and then tested again. The geometry with the highest performance in terms of bottom temperature and pumping power was extended from 15 mm to 45 mm via a linear repeating pattern, shown to be superior to simply stretching the design. The final design was then compared with a 2D geometry that had been generated by an equivalent topology optimisation, with the 3D geometry found to have higher heat transfer efficiency. In this way, the advantages of 3D topology optimisation are demonstrated. A detailed study of the temperature and velocity flow structure in FLUENT suggests that this enhancement is due to improved vertical and spanwise mixing within the channel. The fins of the 3D topology act to force the cold regions of the fluid to interact with the heated surface, thus improving thermal transfer. A simplified version of the 3D geometry confirms that the major fin structures cause the majority of this effect. As such, these results have relevance for future designers of effective heat sinks.

Comparative analysis of hybrid nanofluids with Cattaneo-Christov heat flux model: A thermal case study

The hybrid nanofluids have higher heat transfer efficiency than nanofluids, which has expanded their applications to include electronic cooling, production, automobile, heat transfer, solar energy, heating elements, and biomedical. The current research aims to investigate the effects of Powell-Eyring hybrid nanofluid with slip boundary conditions, and the Cattaneo-Christov heat flux model over a moving surface. By applying the appropriate transformations, the governing boundary layer system is transformed into a dimensionless non-linear ODEs. These non-linear ODEs are computed numerically by using the Keller-Box method via computational tool MATLAB. Physical flow performance and numerical results of physical parameters are obtained by using the MATLAB tool. The researchers noted that hybrid nanofluid have a higher heat transfer rate than nanofluid. The consequences reveal that the velocity profile diminishes with an augmentation in a volumetric fraction of nanoparticles parameter, slip parameter, and porous medium parameter. Furthermore, an increase in thermal radiation parameter, volumetric fraction of nanoparticle parameter, Biot number, and thermal relaxation parameter enhance the temperature layer thickness. To the researchers' knowledge, no one has previously attempted to investigate the current challenge using a mass-based hybrid nanofluid framework. Furthermore, the problem's solution is novel. Indeed, the findings of this research are unique, and the numerical results have never been reported before. Furthermore, the researchers assumed that the findings of this study will be valuable in the development of a hot-wire anemometer or a shielded thermocouple for monitoring wind velocity, among other applications.

The Application of Ozone Micro-nano Bubble Treatment Vegetable Fresh-Keeping Technology in Air Logistics Transportation

In recent years, fresh fruits and vegetables have been sought after by Chinese people. The fresh-keeping technology, storage, and transportation of fruits and vegetables have also attracted a large number of people’s attention. Various methods of preservation, storage, and transportation of fruits and vegetables have begun to appear in the society. Micro and nanobubbles have the characteristics of long stay time, larger than the surface, high surface negative electricity, strong reliability, high efficiency of heat transfer, can cause oxygen free radicals, can greatly improve the actual effect of ozone and ozone utilization rate, and reduce the operation cost. This article aims to study the application of ozone micro-nano bubble processing vegetable fresh-keeping technology in air logistics and transportation, and put forward the idea of applying ozone micro-nano bubble processing fresh-keeping technology to fruits and vegetables fresh-keeping and transportation more widely. This article focuses on the introduction of ozone micro-nano bubbles, fresh-keeping technology, air transportation, and experiments on some fresh-keeping technologies in the article. The experimental results show that the vegetable preservation technology based on ozone micro-nano bubbles can better maintain the moisture and nutrients in the vegetables. The preservation technology of ozone micro-nano bubble treatment has improved the preservation of fruits and vegetables by 12%.

Boosting the photothermal conversion efficiency of MXene film by porous wood for Light-driven soft actuators

Ti3C2Tx (a typical MXene) has been widely used in light-driven actuators due to its outstanding photothermal conversion capability. However, the response speed of these actuators is always slow because the effective irradiated area is limited to their surface. Herein, we propose a wood-based composite material which is made by coating Ti3C2Tx on delignified wood (DW). The high porosity of DW leads to high loading of Ti3C2Tx and provides large irradiated areas, thus enhancing photothermal conversion efficiency. The delignification on wood can expose cellulose with highly hydrophilic surface for rapid diffusion of Ti3C2Tx suspension, and the hydroxy in cellulose can act as binding sites to form stable combination with Ti3C2Tx. Taking advantage of the good compressibility of DW, a simple densification is conducted on TDW (Ti3C2Tx/DW) to greatly shorten the distance between adjacent oxygen-enriched Ti3C2Tx nanosheets, enhancing the conjugation among nanosheets, thus endowing TDW with good flexibility and high heat transfer efficiency. Moreover, we manufacture a light-driven bilayer actuator comprised of TDW as the passive layer and low-density polyethylene (LDPE) as the active layer. Our light-driven actuator exhibits a tremendous angle variation of 160° at a light intensity of 120 mW/cm2. A series of devices based on the TDW/LDPE actuator are demonstrated, including simulated gestures, a four-finger soft gripper, and a bionic flower. Moreover, we propose a light-controlled smart switch which can be used on non-contact (COVID-19) or dangerous (blasting) occasions. Additionally, we present a finite element simulation to predict the bending deformation, which guides the accurate control of the devices.

An experimental study on effects of oily content on flow pattern transition over horizontal tubes in a sewage source heat pump system

The spray sewage heat exchanger is better used for sewage source heat pump systems due to its simple structure and good anti-blocking characteristics. To maintain high heat transfer efficiency of using oilfield wastewater, an experimental sewage source heat pump system is built and experimental studies are carried out to investigate the falling film flow patterns of oily wastewater over the horizontal tubes of spray sewage heat exchanger and effects of oily content. The critical spray density for flow pattern transition is clarified based on visualization by high-speed camera, and the influence of spray temperature and oily content are further analyzed. It is found the flow pattern transition is delayed with the critical spray density increased by 3%–12% when the oily content is raised from 0% to 20%, due to the higher temperature reduces the viscosity of the fluid. The critical spray density of flow pattern transition is also influenced by the spray temperature, which reduce the critical spray density from column flow to column-sheet flow from 0.0828 kg m−1 s−1 at 46 °C to 0.0782 kg m−1 s−1 at 65 °C for wastewater of 15% oily content. The tube surface temperature is further analyzed, and different high heat transfer performance regions are specified with a higher range of spray density for oily wastewater.

Experimental and Numerical Study on Thermal Hydraulic Performance of Trapezoidal Printed Circuit Heat Exchanger for Supercritical CO2 Brayton Cycle

The supercritical carbon dioxide (sCO2) Brayton cycle is the preferred power cycle for future nuclear energy, fossil energy, solar energy, and other energy systems. As the preferred regenerator in the cycle, the printed circuit heat exchanger (PCHE) exhibits a high heat transfer efficiency, compactness, and robustness. The structure design of its internal flow channel is one of the most important factors to enhance the heat transfer and reduce pressure loss. In the present work, a trapezoidal PCHE prototype is designed and manufactured, and its thermal-hydraulic performance as a regenerator is experimentally studied in the sCO2 test loop. The overall heat transfer coefficient exceeds 1.10 kW/(m2·K) and reaches a maximum of 2.53 kW/(m2·K) with the changes in the inlet temperature, the working pressure, and the mass flow rate. Correlations of the Nusselt numbers are proposed on both sides, with the Reynolds numbers ranging from 10,000 to 30,000 and 4800 to 14,000, and the Prandtl numbers ranging from 0.91 to 1.61 and 0.77 to 0.98 on the cold side and hot side, respectively. The pressure drop of the channels calculated by the peeling method using a single-plate straight prototype is less than 7 kPa and 15 kPa on the hot and the cold side, respectively. The heat recovery efficiency is analyzed to evaluate the performance as a regenerator. Finally, simulation works are carried out to verify the experimental results and expand the Reynolds numbers ranging from 3796 to 30,000 and 1821 to 14,000, on the cold side and hot side, respectively. This work provides the test methods and experimental correlations for the development of an efficient PCHE in the sCO2 Brayton cycle.

Technological measures to improve the environmental friendliness of alcohol industry enterprises

The article concerns technological measures to improve the environmental friendliness of food industry enterprises: in particular, aspects of processing waste from the alcohol industry with further use in agriculture (in animal feed). It is important to use methods to optimize the feeding of farm animals, allowing one to involve feed resources that do not have a harmful effect on health and productivity, while significantly reducing the consumption of grain components. This resource is dry distillery grains, which is a waste product of distillery production. Technologies of distillery bard processing include its evaporation with further drying. The main waste at the ethanol plant is whole stillage. It is centrifuged to separate thin stillage from wet grains. Thin stillage contains 5-10% of solids. For reducing energy consumption during the concentration process, it is possible to use a direct contact evaporator (bubbling evaporator). In this article, the bubbling evaporator design was developed. To justify the size of the evaporator, the temperature difference profile along the column length was determined. It is less than 1 and remains constant, which determines the high efficiency of heat transfer. The most effective parameters of the evaporation process according to moisture removal are a gas flow rate of 1.3–1.5 m3/h, air temperature of 400±15. Work results can be used in the design of scalable systems for thin stillage processing and applicable in medium-sized ethanol plants.

Study on condensation flow and heat transfer characteristics of multicomponent mixture in dimple tube

The flow and heat transfer characteristics of methane/propane and methane/ethane/propane have been numerically investigated in the dimple tube. The effect of mass flux, saturation pressure and composition ratio on the characteristics of flow, heat transfer and void fraction are examined. The results indicate that the heat transfer coefficient, friction pressure drop increase with the increase of mass flux and decrease with the pressure drop increased. The heat transfer coefficient of a binary mixture is higher than that of ternary mixture under the same condition. The friction pressure drop of the ternary mixture is greater than that of the binary mixture at high vapor quality. In addition, the influence of geometric parameters is discussed. Higher dimple depth and lower pitch will result in higher heat transfer efficiency. The dimple tube with r = 0.75 mm, p = 5.08 mm, e = 4.33 mm have the best heat transfer performance, and the surface performance factor PFS and the performance factor enhancement PFE are 1.041–1.304 and 0.885, respectively. Besides, the simulation result of void fraction, heat transfer coefficient and friction pressure drop are compared with some general models. Finally, an improved pressure drop model for the enhanced tube is proposed.

Experimental study of mechanical-capillary driven phase-change loop for heat dissipation of electronic devices and batteries

To solve the disadvantages of traditional phase-change heat dissipation technologies, such as instability in two-phase flow and difficulty in active temperature control, a mechanical-capillary driven hybrid phase-change loop (HPCL) is designed and tested. The experiment results show that the heating power and liquid-vapor pressure difference have a decisive influence on the transformation of heat transfer modes. With the increase of heating power while maintaining the liquid-vapor pressure difference unchanged, the baseplate of evaporator undergoes four heat transfer modes, i.e. flooded, partially flooded, thin film evaporation and overheating. Among them, thin film evaporation has the significant advantages of short start-up time and high heat transfer efficiency. Meanwhile, when the baseplate temperature is maintained below 85 ℃, the heat dissipation power is enhanced by about 6.5 times if the liquid-vapor pressure difference is increased from 0 kPa to 15 kPa. Therefore, increasing the liquid-vapor pressure difference is an active means in heat transfer enhancement. The heat transfer modes distribution diagram is drawn by taking into account of power and liquid-vapor pressure difference. Transition criterions between different heat transfer modes are given. The diagram suggests that the thin film evaporation region is in the shape of “horn”. In engineering application, liquid-vapor pressure difference can be regulated adaptively according to the actual operating characteristics of heat dissipation target to achieve the optimal heat dissipation effect. Furthermore, the accurate and rapid control over baseplate temperature can be realized by controlling liquid-vapor pressure difference. In such way, the accuracy of temperature control is within ±0.5 ℃. Therefore, controlling liquid-vapor pressure difference is a simple and effective means of active temperature control.

Construction of highly efficient heat conduction channels within expanded graphite/paraffin phase change composites and their thermophysical properties

Paraffin waxes (PW) are organic phase change materials (PCMs) that can be potentially applied for the storage/release of low-temperature latent heat and thermal management. However, they have serious liquid leakage and poor thermal conductivity, which greatly restrict their practical application. Although numerous studies have been conducted to address these problems, it is challenging to achieve phase change composites (PCCs) that are characterized by high thermal conductivity and excellent phase change behavior. Herein, we put forward a novel strategy for preparing expanded graphite (EG)/PW binary PCCs with EG loading varying in the range of 10–40 wt%. The method is developed by constructing graphite sheets with high orientation inside the PCCs following compression induction. The highly oriented graphite sheets provide channels for highly efficient heat transfer, which significantly improves the thermal conductivity of the resulting EG/PW PCCs. The in-plane thermal conductivities of the EG/PW PCCs are in the range of 10.7–49.7 W m−1 K−1 under 10–40 wt% EG loading conditions, much larger than those of the previously reported EG/PW PCCs with the same EG content. The EG/PW composites also exhibit excellent compatibility, uniformity, thermostability, reliability, and phase change behaviors. These remarkable properties make the EG/PW composites promising for application in thermal management and heat storage. This work provides an efficient and generic strategy for designing and constructing high-efficiency heat transfer channels within the PCCs using sheet-shaped fillers with high thermal conductivity.

Self-regenerative rapid thermal swing adsorption process using structured fiber sorbents for energy-efficient H2O removal

Rapid thermal swing adsorption (RTSA) using hollow fiber sorbents (HFSs) is an emerging separation process that enables significant energy savings. Herein, we propose a self-regenerative RTSA process based on multi-modules of zeolite-13X-impregnated HFSs for energy-efficient H2O removal in various chemical processes. The proposed dehumidification process consumes almost 82% lower energy than the conventional adsorption counterpart for H2O removal because it uses a combination of high heat transfer efficiency and self-regeneration. The steam recovered from the desorption process can be combined with the thermal fluid for H2O desorption from the HFSs, which is referred to as the self-regenerative RTSA process. In addition, the residual sensible heat emitted from the desorption process can be internally integrated into the heating process, which reduces both the sensible heat of the HFSs and desorption heat of H2O. Consequently, the energy evaluation revealed that the newly proposed self-regenerative RTSA process required a total energy of ca. 0.68 GJ t-H2O-1 for H2O adsorption with a heat integration efficiency of 80%. The current work successfully demonstrates an extended application of the RTSA process for dehumidification.