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Showing papers on "Countercurrent exchange published in 2019"


Journal ArticleDOI
TL;DR: In this paper, the authors present the results of an experimental investigation on the heat transfer characteristics of multi-walled carbon nanotube aqueous nanofluids inside a countercurrent double-pipe heat exchanger using porous media.
Abstract: This paper presents the results of an experimental investigation on the heat transfer characteristics of multi-walled carbon nanotube aqueous nanofluids inside a countercurrent double-pipe heat exchanger using porous media. Aluminum porous media (e = 67%) were used because of the construction of the medium, with porous plate media at the center of the inner tube and with three porous plates on the walls of the inner tube. The effects of operating parameters including flow rate (4600 < Re < 7600), mass fractions of nanofluids (0.04–0.25 mass%), and inlet temperature of nanofluids (Tin = 50 °C) on the heat transfer coefficient were investigated. The results indicate that imposing the plate porous media increases the heat transfer coefficient significantly, and the highest increase in the heat transfer coefficient is 35% which is obtained in the test of the lowest mass fraction (0.04 mass%) with three-plate porous media in the experiment range. As the mass fractions increased, the value of heat transfer enhancement assisted by porous media gradually decreased. Also the lower range 100 (L h−1) of the volume flow rate has a powerful enhancement on the enhancement coefficient, while the higher ranges 300 (L h−1) have low influence.

124 citations


Journal ArticleDOI
TL;DR: In this paper, thermal and hydraulic attributes of an ecofriendly graphene nanofluid flowing within a countercurrent spiral heat exchanger are evaluated, and the results show that the value of effectiveness is much great (higher than 0.85) in all cases under investigation.

104 citations


Journal ArticleDOI
TL;DR: In this paper, the authors proposed a microchannel design with rectangular ribs on the flow centerline along the fluid path to enhance mixing for cooling fluid and create better heat transfer for warm surfaces.
Abstract: In this numerical study, laminar flow of water nanofluid/GNP–SDBS (graphene nanoplatelet–sodium dodecylbenzene sulfonate) for 0–0.1% solid nanoparticles mass fraction was investigated for Reynolds numbers of 50–1000 in 3D space via finite volume method. In the newly proposed microchannel design, the cooling fluid is moving in countercurrent in the upper and lower layers of the microchannels, and there are cavities and sinusoidal routes on the solid walls of the microchannel, and the presence of rectangular ribs on the flow centerline along the fluid path enhances mixing for cooling fluid and creates better heat transfer for warm surfaces. The results of this study show that this special design of the microchannel can have a substantial increase in Nusselt number and heat transfer so that in the considered geometry by adding solid nanoparticles mass fraction it is possible to increase average Nusselt number for each Reynolds number by approximately 20%. Also, the mixing of the fluid because of formation of secondary flows has a strong effect on making the temperature distribution uniform in the cooling fluid and solid bed (wall) of the microchannel, especially in the lower layer. The upper layer of the microchannel always has a lower temperature due to indirect contact with heat flux compared with the lower layer. In this study, by increasing Reynolds number and mass fraction of solid nanoparticles the Nusselt number is increased and heat resistance of the lower wall of the microchannel is reduced. Based on the investigation of flow field and heat transfer, the use of the proposed design of the microchannel is recommended for Reynolds number less than 300.

60 citations


Journal ArticleDOI
TL;DR: The objective of this study was to design and test a three‐stage countercurrent DF system that could achieve at least 99.9% buffer exchange over 24 hr of continuous operation and provide important insights to the design and operation of a continuous process for antibody formulation.
Abstract: There is growing interest in the development of fully integrated and continuous biomanufacturing processes for the production of monoclonal antibody products. A recent study has demonstrated the feasibility of using a two-stage countercurrent diafiltration (DF) process for continuous product formulation, but this system did not provide sufficient levels of buffer exchange for most applications. The objective of this study was to design and test a three-stage countercurrent DF system that could achieve at least 99.9% buffer exchange over 24 hr of continuous operation. Experimental data were obtained using concentrated solutions of human immunoglobulin G as a model protein, with the extent of vitamin B12 removal used to track the extent of DF. Pall Cadence™ inline concentrators with Delta 30 kD regenerated cellulose membranes were used in the three stages to achieve high conversion in a single pass. The three-stage system showed stable operation with >99.9% vitamin B12 removal and a minimal increase in pressure over the full 24 hr. Modules were effectively cleaned using sodium hydroxide, with nearly complete recovery of water permeability. A simple economic analysis was presented that accounts for the trade-offs between quantity of buffer used and membrane costs for this type of countercurrent staged DF process. The results provide important insights to the design and operation of a continuous process for antibody formulation.

23 citations


Journal ArticleDOI
Brendan Bulfin1
TL;DR: A straightforward approach is formulated in terms of an exchange coordinate, in order to determine an upper bound of species exchange in chemical reaction systems, subject to the second law of thermodynamics and conservation of mass.
Abstract: Countercurrent reactors can be utilized in chemical reaction systems which involve either a reaction between flows of different phases, or reactions between flows separated by a selective permeable membrane. This idea is quite similar in nature to a countercurrent heat exchanger, where the inlet of one participating flow is exposed to the outlet of the opposite flow. A countercurrent configuration can therefore improve the reaction conversion extent and transport properties. Here we formulate a straightforward approach in terms of an exchange coordinate, in order to determine an upper bound of species exchange in such systems, subject to the second law of thermodynamics and conservation of mass. The methodology is independent of the specifics of reactor design and can be generally applied to determine the maximum thermodynamic benefit of using a countercurrent reactor. We then demonstrate the analysis for a number of thermochemical fuel production routes; membrane thermolysis of carbon dioxide, dry methane reforming across a membrane, reverse water gas shift across a membrane, and the thermochemical ceria cycle.

15 citations


Journal ArticleDOI
TL;DR: In this article, the effects of rotational speed, liquid initial velocity in the cavity, and the packing zone of a countercurrent rotating bed on liquid phase flow patterns, droplet velocity, average droplet diameter, and droplet size distribution were measured using a charge-coupled device (CCD) camera in the air-water system.
Abstract: A rotating packed bed (RPB) is a new type of process intensification equipment. Its packing zone is an important mass transfer zone. However, the issue of liquid flow in the RPB remains unclear. In this work, the effects of rotational speed, liquid initial velocity in the cavity, and the packing zone of a countercurrent rotating bed on liquid phase flow patterns, droplet velocity, average droplet diameter, and droplet size distribution were measured using a charge-coupled device (CCD) camera in the air–water system. Experimental results show the influence of rotational speed and liquid initial velocity on fluid flow characteristics. Computational fluid dynamics modeling was employed to analyze the characteristics of liquid flow. Two-dimensional numerical simulation of gas–liquid two-phase flow was achieved using the volume of fluid model in the multiphase flow model and the Reynolds stress model in the turbulence model. Simulation results are consistent with the experimental rules. In addition, correlations were established to predict the average droplet diameter, the rotational speed, and the liquid initial velocity. The predicted values were in agreement with the experimental values, with deviations generally within ±15%.

12 citations


Journal ArticleDOI
TL;DR: In this paper, an approximate approach of mathematical modeling of mass transfer in a randomly packed bed at turbulent gas motion and countercurrent laminar wave flow of liquid film is analyzed.
Abstract: The paper considers the processes of mass transfer between phases in countercurrents of gas and liquid in stationary packed beds of industrial randomly packed column apparatus. Such beds are widely used in heat and mass transfer, separation, and reaction processes in the oil and gas processing, petrochemistry, and other industries. An approximate approach of mathematical modeling of mass transfer in a randomly packed bed at turbulent gas motion and countercurrent laminar wave flow of liquid film is analyzed. The basic concepts of the multispeed continuum model, in which the transfer equations are written for each phase separately, are used. The phases fill one space, the volume of the continuous phase (gas) exceeding by far that of the liquid one. The interaction of the phases is reflected in averaged transfer terms, which take into account the interfacial transfer phenomena. Those are the mass transfer coefficients and the driving forces of the processes. The concentration profiles of the components are found from the solution to differential mass transfer equations written for a cylindrical channel with a volume source of mass. This approach can be used in the absence of experimental data on the structure of gas and liquid flows in a packed bed, for example, when designing new contact elements.

11 citations


Journal ArticleDOI
TL;DR: In this article, the effect of drop size distribution on the mass transfer efficiency of a two-phase countercurrent extraction process was investigated in a pilot plant of L-shape pulsed packed extraction column.
Abstract: The objective of this work is to model the effect of drop forward-mixing on the mass transfer efficiency of a two phase countercurrent extraction process. Based on the flow mechanism and drop size distribution in extraction columns, a novel model with a simplified sequential algorithm is developed. Unlike the other models that use mean diameter of the dispersed phase droplets, this model accurately considered the effect of drop size distribution on mass transfer efficiency. On the base of this model the volumetric overall mass transfer coefficient has been investigated in a pilot plant of L-shape pulsed packed extraction column by using two liquid systems of toluene/acetone/water and butyl acetate/acetone/water. It is found that, although the mass transfer coefficient related to the large droplets is larger but the corresponding volumetric overall mass transfer coefficient is less than that related to the small droplets. Therefore, any factor that reduces the drop size can improve the efficiency of mass transfer. Furthermore, the effect of operational variables and physical properties including the dispersed and continuous phases flow rates, pulsation intensity and interfacial tension have been considered on mass transfer coefficients. It has been found out that the pulsation intensity and the continuous phase flow rate have seriously affected on mass transfer coefficient, however, the dispersed phase flow rate has a weaker effect. Finally, new correlations are proposed to accurately predict the mass transfer coefficient, axial mixing and drop size distribution. Good agreement between predictions and experiments was found for all operating conditions that were investigated.

11 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the effects of particle size and gas velocity on the heat recovery process and recovery gas exergy in a moving bed with a fixed bed height, and detailed results regarding the particle cooling behavior, necessary cooling time, particle and gas temperature distribution in the bed, and the pressure drop of each case were obtained.

9 citations



Journal ArticleDOI
TL;DR: In this article, a flat-sheet membrane-based absorptive dehumidification module with different flow arrangements (i.e., cocurrent, countercurrent, and cross-flow configurations) using an aqueous lithium chloride desiccant was evaluated.

Journal ArticleDOI
TL;DR: In this article, the process of gas cooling with a liquid in a countercurrent packed column (scrubber), where the phases are in direct contact, is described, and a system of differential equations for heat transfer in gas and liquid phases and moisture mass transfer is given.
Abstract: The process of gas cooling with a liquid in a countercurrent packed column (scrubber), where the phases are in direct contact, is described. The system of differential equations for heat transfer in gas and liquid phases and moisture mass transfer is given. Equations for determining the fields of gas enthalpy distribution, liquid temperature, moisture content in the gas along the packed bed height are derived through transition to a cellular model. The adequacy of the proposed equations is validated in practice. The packed column is updated, which involved replacement of plates by packings produced by OOO IVTs Inzhekhim (EPC Chemical Engineering LLC), which enhanced the efficiency of pyrogas cooling with water in ethylene production.

Journal ArticleDOI
TL;DR: In this article, the hydrodynamic performance of the TRST in a gas-liquid countercurrent flow column was investigated experimentally, and the results showed that the operating field can be divided into low and high loading areas according to the increasing rate of the pressure drop.
Abstract: The hydrodynamic performance of the TRST in a gas-liquid countercurrent flow column was investigated experimentally in this article. The results show that the operating field can be divided into low and high loading areas according to the increasing rate of the pressure drop. The space utilization of the tray is low, and the flow patterns are mainly droplet-column and continuous film flows. The pressure drops of the tray at each installed locations are different, indicating that the gas-liquid load of each tray is unbalanced. Compared with concurrent flow operation, the range of gas flux is at least 45% less, and the liquid flux range is at least 37.5% less. Compared with other new tray types under countercurrent flow operation, the pressure drop of the TRST is smaller, less than 300 Pa, but the range of gas-liquid flux is also narrow. The empirical models of the pressure drops, loading curve, and flooding curve agree well with the experimental data.

Journal ArticleDOI
TL;DR: The Continuum Particle Distribution Modeling (CPDM) satisfactorily predicts countercurrent fermentation using mixed microbial cultures that digest various feedstocks and is used to simulate multi-stage countercurrent saccharification of α-cellulose.
Abstract: Countercurrent saccharification is a promising way to minimize enzyme loading while obtaining high conversions and product concentrations However, in countercurrent saccharification experiments, 3–4 months are usually required to acquire a single steady-state data point To save labor and time, simulation of this process is necessary to test various reaction conditions and determine the optimal operating point Previously, a suitable kinetic model for countercurrent saccharification has never been reported The Continuum Particle Distribution Modeling (CPDM) satisfactorily predicts countercurrent fermentation using mixed microbial cultures that digest various feedstocks Here, CPDM is applied to countercurrent enzymatic saccharification of lignocellulose CPDM was used to simulate multi-stage countercurrent saccharifications of a lignocellulose model compound (α-cellulose) The modified HCH-1 model, which accurately predicts long-term batch saccharification, was used as the governing equation in the CPDM model When validated against experimental countercurrent saccharification data, it predicts experimental glucose concentrations and conversions with the average errors of 35% and 47%, respectively CPDM predicts conversion and product concentration with varying enzyme-addition location, total stage number, enzyme loading, liquid residence time (LRT), and solids loading rate (SLR) In addition, countercurrent saccharification was compared to batch saccharification at the same conversion, product concentration, and reactor volume Results show that countercurrent saccharification is particularly beneficial when the product concentration is low The CPDM model was used to simulate multi-stage countercurrent saccharification of α-cellulose The model predictions agreed well with the experimental glucose concentrations and conversions CPDM prediction results showed that the enzyme-addition location, enzyme loading, LRT, and SLR significantly affected the glucose concentration and conversion Compared to batch saccharification at the same conversion, product concentration, and reactor volume, countercurrent saccharification is particularly beneficial when the product concentration is low

Journal ArticleDOI
TL;DR: In this article, a modified correlation for falling water film evaporation in passive containment was developed for a wall surface temperature range of 71-90 ˚C, and the experimental data showed that the high evapse temperature significantly enhanced evapse.


Journal ArticleDOI
TL;DR: Passive countercurrent microextractors with high throughput have potentially broad applications in industrial-scale solvent extraction and hazardous waste disposal as discussed by the authors. But no design guideline has been proposed for them.
Abstract: Passive countercurrent microextractors with high throughputs have potentially broad applications in industrial-scale solvent extraction and hazardous waste disposal. To date, no design guideline ha...

Journal ArticleDOI
TL;DR: In this paper, the structural form of the CCDAF tank and its process parameters are the required conditions to achieve countercurrent collision and cocurrent adhesion, and the optimal conditions are as follows: contact zone ascending velocity 10 mm/s, separation zone separation velocity 1.5 mm /s, dissolved gas pressure 0.45 MPa, and recirculating dissolved gas distribution ratio R1/R2 1:1.
Abstract: The countercurrent–cocurrent dissolved air flotation (CCDAF) process is a new type of air flotation process integrating countercurrent collision and cocurrent flow adhesion processes. The structural form of the CCDAF tank and its process parameters are the required conditions to achieve countercurrent collision and cocurrent adhesion. In this study, eight CCDAF tank process models were established with a flow rate of 0.5 m3/h. Flow field numerical simulation and process optimization of a CCDAF tank was conducted using Fluent software. The simulation results show that the optimal conditions for the CCDAF process are as follows: contact zone ascending velocity 10 mm/s, separation zone separation velocity 1.5 mm/s, dissolved gas pressure 0.45 MPa, and recirculating dissolved-gas distribution ratio R1/R2 1:1. Under these operating conditions, the flow state in the flotation tank is the most stable and the gas in the contact zone is evenly distributed. According to the simulation results, a 5 m3/h pilot plant was built. The structural dimensions were: B × L × H = 1,020 mm × 1,300 mm × 1,350 mm. The test results show that the CCDAF has a significant decontamination effect and is clearly superior to the cocurrent flow DAF process and countercurrent flow DAF process.

Patent
30 Aug 2019
TL;DR: In this article, a direct heat exchange based cooling crystallization method is proposed, which comprises steps as follows: an organic medium which is insoluble with a solute solution and has a freezing point lower than 5 DEG C and a boiling point higher than 30 DEGC is adopted as a heat transfer medium; the organic medium is cooled to be 1-4 DEG c lower than an aqueous inorganic salt solution, low-temperature organic medium countercurrent and a solution are contacted in a crystallizer for heat exchange, the low-time temperature organic medium
Abstract: The invention relates to a direct heat exchange based cooling crystallization method. The method comprises steps as follows: an organic medium which is insoluble with a solute solution and has a freezing point lower than 5 DEG C and a boiling point higher than 30 DEG C is adopted as a heat transfer medium; the organic medium is cooled to be 1-4 DEG C lower than an aqueous inorganic salt solution,low-temperature organic medium countercurrent and a solution are contacted in a crystallizer for heat exchange, the low-temperature organic medium takes away heat released by crystallization, inorganic salt is separated out from the aqueous solution, the organic medium is sent to outside of the crystallizer and is recycled after being cooled again, and continuous cooling crystallization of the inorganic salt is realized. The method has the advantages of being high in heat exchange efficiency, low in equipment investment and high in operability, avoiding crystallizing blockage and reducing labor intensity, and is applicable to cooling crystallization of multiple materials.

Journal ArticleDOI
TL;DR: In this article, the effect of axial heat conduction in the wall on temperature distribution along a heat exchanger with parallel flow of heat carriers and on heat exchange effectiveness has been investigated.
Abstract: The effect of heat conduction in the wall on temperature distribution along a heat exchanger with parallel flow of heat carriers and on heat exchanger effectiveness has been investigated. The problem was solved based on a system of one-dimensional (cross-section averaged) energy equations for two heat carriers and the heat conduction equation for the wall. The wall ends were assumed to be heat insulated. The system was solved using the finite-difference technique. For the special cases, the system was solved analytically. The parameter determining the effect of the wall axial conduction on the heat exchanger effectiveness and the value of this parameter at which this effect can be neglected have been found. This dimensionless parameter is proportional to the heat transfer coefficient, thermal resistance of the wall, and square of the heat-exchanger length to the tube wall thickness ratio. Besides the parameter describing the effect of axial heat conduction, the solution depends on the number of heat transfer units and the ratios of thermal equivalents of the heat carriers and heat transfer coefficients on the hot and cold sides. For a cocurrent flow of the heat carriers, the best result is attained when the value of these two ratios is 1. In this case, the effectiveness of the heat exchanger does not change as compared to that with no effect of the axial heat conduction of the wall. For a countercurrent heat exchanger, the effect of axial heat conduction on the heat exchanger effectiveness is at a minimum when the ratios of thermal equivalents of the heat carriers and heat transfer coefficients on the cold and hot sides are equal. The estimations based on the results of calculations demonstrate that, in case of microchannel heat removal, the effect of axial heat conduction in the heat exchanger wall can considerably reduce the heat exchanger effectiveness.

Patent
08 Mar 2019
TL;DR: In this article, a double-sided staggered printed circuit board type heat exchange plate and a heat exchanger are described, and the heat exchange area and heat exchange effect are effectively improved.
Abstract: The invention discloses a double-sided staggered printed circuit board type heat exchange plate and a heat exchanger, and belongs to the technical field of the heat exchangers. The heat exchange platecomprises a plurality of first fluid passages and a plurality of second fluid passages; the first fluid passages are formed in one side of the heat exchange plate at intervals, the second fluid passages are formed in the other side of the heat exchange plate, and the first fluid passages and the second fluid passages are formed at intervals in the heat exchange plate. According to the heat exchange plate, the double-sided staggered fluid passages are adopted to form countercurrent or downstream heat exchange, so that full-main surface heat exchange is achieved, the secondary heat exchange surface does not exist, and the heat exchange area and the heat exchange effect are effectively improved; and in addition, the heat exchange plate is relatively thin, so that the size and the weight of aheat exchange module core are further reduced, and the compactness and the heat exchange performance of the heat exchanger are improved.


Journal ArticleDOI
TL;DR: In this paper, the thermal field of a particle for Bi > 0 with an ideal spherical shape and the behavior of the temperature in the fluid phase with countercurrent contact was studied.
Abstract: This article is devoted to the solution of the thermal field of a particle for Bi > 0 with an ideal spherical shape and the behavior of the temperature in the fluid phase with countercurrent contact.After establishing the underlying simplified assumptions and defining the initial and boundary conditions in the form of dimensionless criteria, a mathematical formulation of the problem is transformed into a suitable and solvable form. The formulation is then used in the analysis.

Patent
11 Jun 2019
TL;DR: In this article, the utility model discloses a device for continuous countercurrent leaching of grinding waste, which consists of an auger motor, a countercurrent cylinder, a feeding pipe, a reaction cone, an augers and a first filter screen.
Abstract: The utility model discloses a device for continuous countercurrent leaching of grinding waste. The device comprises two countercurrent leaching devices and a solid-liquid separation box, each of the two countercurrent leaching devices consists of an auger motor, a countercurrent cylinder, a feeding pipe, a reaction cone, an auger and a first filter screen; the top of the countercurrent cylinder inthe first countercurrent leaching device is communicated with the reaction cone in the second countercurrent leaching device through a discharge pipe, the top of the countercurrent cylinder in the second countercurrent leaching device is connected with the top end of the solid-liquid separation box through the other discharge pipe, and the packing auger is arranged in the countercurrent cylinder.According to the utility model, the inner conical cylinder is arranged; grinding waste and leaching liquid can be conveniently placed for leaching reaction; and the inner conical barrel can periodically rotate in the outer conical barrel, so that stirring of a reaction solution is achieved, the leaching reaction is fully conducted, through the arrangement of the two sets of countercurrent leaching devices, secondary leaching of the grinding waste is facilitated, and it is guaranteed that metal materials in the grinding waste can be fully extracted.

Patent
21 May 2019
TL;DR: In this article, a method for preparing high-purity medical cholesterol through continuous countercurrent microchannel extraction is presented, which belongs to the technical field of chemical engineering, and can be used for efficiently and quickly preparing the high-protein medical cholesterol.
Abstract: The invention discloses a method for preparing high-purity cholesterol through continuous countercurrent microchannel extraction, and belongs to the technical field of chemical engineering. The methodcomprises the following steps that (1) n-heptane, ethyl acetate, methanol and water are mixed according to the volume ratio of (0.9-1.2):(1.1-1.3):(0.8-1.0):1, standing is conducted to separate upperand lower phases, a crude cholesterol product is dissolved with an upper phase solution, and a lower phase solution is adjusted with acetic acid to serve as an extraction agent, wherein the PH is adjusted to 3.7-4.5; (2) the extraction agent is adopted for conducting continuous countercurrent microchannel extraction on a solution of the crude cholesterol product; (3) the cholesterol solution obtained by countercurrent microchannel extraction is evaporated and recrystallized with ethanol to obtain the cholesterol. By means of the method for efficiently and quickly preparing the high-purity medical cholesterol, the continuous countercurrent microchannel extraction technology is adopted for separating and purifying the crude cholesterol product to obtain the high-purity medical cholesterol.

Patent
01 Feb 2019
TL;DR: In this paper, a coal mine gas one-way flow concentration self-adaptive oxidation device comprises a gas inlet system, a downstream heat storage oxidation bed, a starting combustion chamber, a countercurrent heat storage oxidizer bed and an exhaust system which are communicated in sequence.
Abstract: A coal mine gas one-way flow concentration self-adaptive oxidation device comprises a gas inlet system, a downstream heat storage oxidation bed, a starting combustion chamber, a countercurrent heat storage oxidation bed and an exhaust system which are communicated in sequence, and the downstream heat storage oxidation bed, the starting combustion chamber and the countercurrent heat storage oxidation bed are arranged in an inverted U-shaped structure; the gas inlet system is sequentially provided with a gas inlet gas concentration sensor, a gas inlet flow sensor, an electric control valve I anda gas-gas heat exchanger; a flow uniformizing chamber is arranged at the bottom of the thermal oxidation bed, the upper part of the flow uniformizing chamber is filled with a porous heat accumulator,and high-temperature heat pipes I and II are arranged in the porous heat accumulator; an internal heat collector is arranged in the starting combustion chamber; the high-temperature heat pipe is connected with the starting combustion chamber; and the exhaust system is communicated with the countercurrent heat storage oxidation bed through the gas-gas heat exchanger. According to the utility model, greenhouse gas emission can be reduced, gas continuous flow concentration self-adaptive oxidation is realized, the gas oxidation efficiency and utilization rate are improved, and the energy utilization efficiency is high.

Patent
18 Oct 2019
TL;DR: In this article, the authors proposed a gas-liquid countercurrent heat exchange device with a plurality of liquid channels arranged in the length direction, where the gaps between the adjacent layers are arranged to form the gas flow channels.
Abstract: The utility model relates to the field of heat exchangers. The utility model provides a gas-liquid countercurrent heat exchange device. The device comprises a strip-shaped pore plate, the strip-shapedpore plate is provided with a plurality of liquid channels arranged in the length direction. The liquid channel vertically penetrates through the strip-shaped pore plate, the strip-shaped pore plateis rolled into a multi-layer tube plate structure, adjacent layers are arranged at intervals to form an airflow channel, an air inlet is formed in the lower end of the airflow channel, an air outlet is formed in the upper end of the airflow channel, a liquid inlet is formed in the upper end of the liquid channel, and a liquid outlet is formed in the lower end of the liquid channel. According to the gas-liquid countercurrent heat exchanger, the strip-shaped pore plates with the liquid channels are rolled into a multi-layer tube plate structure, and the gaps between the adjacent layers are arranged to form the gas flow channels, so that liquid flows through the liquid channels from top to bottom, air flows through the gas flow channels from bottom to top, countercurrent heat exchange betweengas and liquid is realized, and the heat exchange efficiency is improved.

Patent
24 Dec 2019
TL;DR: In this paper, a hot air/water indirect forced countercurrent heat exchange soil heat supplementing system of a ground source heat pump is proposed, where a constant pressure water supplementing valve is arranged on the outer side of the expansion tank.
Abstract: The utility model provides a hot air/water indirect heat exchange soil heat supplementing system of a ground source heat pump. Wherein a water inlet of the buried pipe heat exchanger is communicated with a water outlet of the circulating water pump, a water inlet of the surface air cooler is communicated with a water outlet of the buried pipe heat exchanger, and a water inlet of the expansion tankis communicated with a water outlet of the surface air cooler. A water outlet of the expansion tank is communicated with a water inlet of the circulating water pump; a constant-pressure water supplementing valve is arranged on the outer side of the expansion tank; an air/water indirect forced countercurrent heat exchange device is arranged on the outer side of the surface air cooler; the air/water indirect forced countercurrent heat exchange device comprises an air duct and a fan arranged in the air duct, the surface air cooler is located in the air duct, the fan is arranged on one side of anair outlet of the air duct, and the air/water indirect forced countercurrent heat exchange device has the advantages of being low in equipment investment cost, low in operation energy consumption, small in water consumption and simple and reliable in technology.

Journal ArticleDOI
01 Jun 2019
TL;DR: In this paper, the effectiveness-NTU method was adapted to gas-liquid countercurrent absorbers to determine the overall mass transfer coefficient, KLa, of the apparatus in operation.
Abstract: In this study, the Effectiveness-NTU method, which is usually applied to heat exchanger design, was adapted to gas–liquid countercurrent absorbers to determine the overall mass transfer coefficient, KLa, of the apparatus in operation. It was demonstrated that the e-NTU method could be used to determine the KLa using the Henry coefficient of the solute to be transferred (HVOC), the gas flow-rate (QG), the liquid flow-rate (QL), the scrubber volume (V), and the effectiveness of the absorber (e). These measures are calculated from the gaseous concentrations of the solute measured at the absorber inlet (CGin) and outlet (CGout), respectively. The e-NTU method was validated from literature dedicated to the absorption of volatile organic compounds (VOCs) by heavy solvents. Therefore, this method could be a simple, robust, and reliable tool for the KLa determination of gas–liquid contactors in operation, despite the type of liquid used, i.e., water or viscous solvents.

Patent
26 Mar 2019
TL;DR: In this article, a steady-state solid-liquid two-phase solute concentration distribution model in a continuous reverse flow mass transfer process is presented, which utilizes a CFD model to obtain a flow field matrix.
Abstract: The invention discloses a steady-state solid-liquid two-phase solute concentration distribution model in a continuous reverse flow mass transfer process. The volume flow of a solid phase in a model independent variable is changed; Volume flow rate of liquid phase, the retention time of the solid phase in the continuous reverse flow mass transfer space is reserved, the coefficient of an equation set and the intermediate parameter of a matrix equation are obtained again, and a solute concentration distribution matrix meeting the expected requirement, the volume flow of the solid phase corresponding to the distribution matrix, the volume flow of the liquid phase and the retention time of the solid phase in the continuous reverse flow mass transfer space are obtained; The model utilizes a CFDmodel to obtain a flow field matrix. performing finite element redivision on the continuous countercurrent reaction process on the basis; meanwhile, solid-liquid two-phase diffusion mass transfer andconvection mass transfer are considered, a solid-phase, liquid-phase and boundary solute conservation equation set is established, compared with a mass transfer process directly defined in a CFD original program, calculation resources are greatly saved, the calculation efficiency of concentration field distribution is improved, and the method is more convenient to write into hardware to carry outlow-cost operation.