Design Of Plate Heat Exchangers Research Articles

Multidisciplinary Optimization of Gyroid Topologies for a Cold Plate Heat Exchanger Design

Abstract The strive to reduce the environmental impact of aviation has led to electrification and increasing demand for powerful on-board power electronic systems. These high-performance electrical components are bound to produce significant amounts of low-quality heat waste that, if not dissipated properly, will lead to malfunctioning and even permanent damage. For this reason, high-performance heat exchangers (HX) represent a key enabler for future advances in aircraft systems electrification and are vital to meet net zero goals and reduce the aviation's carbon footprint. For a given volume of the exchanger, the heat flow rate can be increased by adopting more sophisticated fluid domains. However, excessive geometrical complexity will lead to an increase in pressure losses, often resulting in inhomogeneous temperature distributions. In this paper, a novel optimization procedure is employed to maximize the efficiency of a high-performance heat exchanger, while minimizing overall pressure loss and temperature gradients. The optimization is performed with full three-dimensional high-fidelity computational flow simulations. The geometry of the fluid domain is constituted by triply periodic minimal surfaces (TPMS), with a parametrization based on thickness and aspect ratios, done by using the ntopology suite. To assess the performance gain, the topology-optimized design is compared against the datum case and a conventional serpentine design.

Synthesis of heat-integrated water networks considering detailed heat exchanger design

This paper introduces a mathematical programming approach for synthesising heat-integrated water networks (HIWNs) with a detailed heat exchanger design. A common assumption of constant heat capacities of water streams is relaxed. The specific heat capacity of water is now considered as a nonlinear function of temperature to avoid errors in calculating energy balances. In addition, most previous works have assumed constant individual heat transfer coefficients for water streams and utilities when estimating heat transfer areas. This assumption can lead to significant over- or under-estimation of heat transfer areas. In this research, individual and overall heat transfer coefficients for heat exchangers are calculated based on the detailed design of plate heat exchangers for heat recovery. The objective function of the proposed mixed integer nonlinear programming (MINLP) model is to minimise the total annualised cost (TAC). The TAC includes operating costs for freshwater and utilities, pumping costs for overcoming pressure drops in heat exchangers, and investment costs for heat exchangers. Three examples are solved in this work to verify the proposed model.

Optimizing Plate Heat Exchanger Design for Steam Condensate Recovery Systems

Condensate water is typically generated as a by-product during the use of steam as a medium for heat transfer. In order to optimize the transfer area, the chemical industry often employs heat exchangers, such as the plate heat exchanger (PHE), which provides flexibility in adjusting the space area for heat transfer. This case study examines the optimization of plate geometry dimensions to enhance the heat transfer process of PHE equipment design. The optimization process involves mathematical equations and a literature review of the design of this type of heat exchanger. Improving the dimensional aspect of the plate geometry results in an increase in the overall heat transfer coefficient (U) and a reduction in the number of design requirements used. The study's estimation results suggest that the PHE design has a limitation on plate dimensions, which should be less than 0.3×0.6 m. Additionally, it is important to consider the pressure drop value, which should not exceed 29.07 kPa. A review of the chemical industry field provided estimated options for plate size and quantity, both of which support the optimization of heat transfer rate and design constraint thresholds. The implementation of the design has been found to enhance the performance of the planning process for recovering steam condensate water.

Advanced modelling and iterative approach for high-accuracy PCHE design in SCO2 Brayton cycle

This study addresses the crucial challenge in the design of Plate Heat Exchangers (PCHEs) for SCO2 Brayton cycles, caused by inadequate mathematical models and heat transfer correlations. The paper introduces novel PCHE models that surpass existing approaches in accuracy and versatility. Three approximations (Models 1, 2, and 3) are evaluated and improved upon. Two new models, Basic Heat Transfer Analysis (Model 4) and Modified Heat Transfer Analysis (Model 5), are proposed, validated, and compared in both 2D and 3D scenarios. The innovation lies in the introduction of an Iterative Method to determine wall temperatures and integrating high-precision heat transfer correlations. Results demonstrate Model 5′s superiority over all models, achieving exceptional accuracy for standard and non-standard PCHE configurations. For standard setups, Model 5 exhibits ± 0.50 % RE, RMSE = 0.21 (2D), Error = 0.89 % (3D), outperforming other models. For non-standard configurations, Model 5 maintains superior accuracy (2D: RE = -0.5 %∼2%, RMSE = 0.67, 3D: Error = 1.53 % and 1.98 %).The study validates Model 4 and 5′s heat transfer coefficients through the Jackson correlation against CFD results, surpassing previous models using the Gnielinski correlation. In summary, the study introduces Model 5 as a novel, accurate, and versatile solution for PCHE design. The proposed Iterative Method further enhances accuracy and applicability. The paper's originality lies in the development of Model 5, its verification, and its recommendation as a preferred PCHE design tool, addressing critical industry needs and research gaps.

An advanced Grid Diagram for heat exchanger network retrofit with detailed plate heat exchanger design

This paper presents a method for heat exchanger network (HEN) optimisation considering plate heat exchangers (PHEs), incorporating detailed PHEs design. The developed method starts from a mathematical model based on the Advanced Grid Diagram, which can optimise the HEN structure. The model minimises the energy consumption cost with the constraints that enable a solution thermodynamically feasible. Then comes the heat exchanger type selection part, which is provided by a graphical tool helping to identify which types of the heat exchanger are feasible. The feasible temperature range can be easily visualised to avoid the temperature violation of PHEs. This selection part integrates the area calculation and cost calculation with the detailed heat exchanger design. The method has been tested by a case study of crude oil distillation system illustrating that the application of brazed plate heat exchangers (BHEs) of CB series manufactured by Alfa Laval can save 6.6% of the investment cost for new heat exchangers compared with the retrofit plan that only shell-and-tube and double pipe heat exchangers are used.

Experimental and numerical study of innovative plate heat exchanger design in simplified hot box of SOFC

The inverse computational fluid dynamics simulation combined with experimental temperature measurements is applied to investigate the three-dimensional natural convection of an innovative plate heat exchanger in a hot box. This natural convection conjugate heat transfer separated by all insulating walls of the hot box is solved by couping. The upper low-temperature duct is located between the lower high-temperature duct and the top wall of the hot box. If the root mean square error between the obtained numerical results of the air temperature and the experimental data at the selected measurement locations is the smallest among all flow models, then the appropriate flow model and wall function can be predicted. Furthermore, more accurate natural convection heat transfer characteristics and the heat transfer rate applied to the two ducts can be determined. An important finding is that the realizable k-ε model combined with the standard wall function and the zero-equation model are suitable for problems with smaller and larger duct spacings, respectively. This means that the location of the two ducts may influence the selection of an appropriate flow model. In addition, increasing the number of grid points does not necessarily lead to more accurate results. An optimal total grid points can be obtained. The obtained heat transfer coefficients on the upper surfaces of the two ducts are also in good agreement with the existing correlation. This comparison further verifies that the present results and the selected flow model are accurate. Due to the blocking, buoyancy and heat dissipation effects of the two ducts, the formation of the main vortex, the velocity patterns and air temperature contours obtained by the two selected appropriate flow models are slightly different. The two gaps between the edges of the ducts and the side walls of the hot box can destroy the structure of natural circulation and improve the heat accumulation under the two ducts. The air flows slightly in the direction of the larger gap so that the velocity pattern and the temperature contour become asymmetric. As far as we know, these findings have not yet appeared in the public literature. Therefore, this study is novel and innovative.

Plate heat exchanger design for the utilisation of waste heat from exhaust gases of drying process

The vapour condensation is typical for processes of waste heat recovery from exhaust gases. It complicates the selection of condensers and requires reliable correlations for estimation of heat transfer coefficients and pressure drop in the unit. In the presented paper, a novel model was elaborated to be applied for commercially produced plate heat exchangers (PHEs) assembled from plates with different geometries of corrugations, which accounts the change of process parameters at the main corrugated field, in PHE collectors and channels distribution zones. The process of waste heat recovery from exhaust gases after tobacco drying is discussed in the case study. The pilot unit assembled with PHE of TS-6MFG type manufactured by Alfa Laval was installed at a tobacco factory. The examined condensing media was an incoming air-steam mixture with 10% of air content and temperature equal to 140 °C. The comparison of modelling results and data of industrial operation has shown good accuracy of prediction. It allowed recommending obtained correlations and developed mathematical model for the design of plate heat exchangers in applications with heat utilisation from exhaust gases after drying processes in the industry, with a considerable saving of heat energy. In the considered example, it is up to 640 kW or 2090 kJ/kg of exhaust gases.

판형 열교환기 쉐브론 각도에 따른 전열성능 비교에 관한 연구

The development of chevron-type corrugated plates, as it is today, has started with strong demand for energy efficiency improvement since the oil shock in the 1970s. In a typical plate heat exchanger, it is almost impossible to design it with a thermal length that exactly fits given design conditions. Therefore, some over-surfacing is required in designing heat exchangers. To reduce over-surfacing, two types of heat plates were developed: high θ (chevron angle=120°) and low θ (60°) plates. They can also be used in combination. The two types of heat plates can form three types of channels: high θ channel, low θ channel, and mixed θ channel. The purpose of this study is to experimentally figure out the thermal performance characteristics of each channel with a real product which can be used in many industries and to provide their basic data on a design of plate heat exchangers.

Effect of flow maldistribution on the optimal design of plate heat exchanger using constrained multi objective genetic algorithm

In this study, thermal and hydraulic optimization of plate heat exchanger is presented. In the thermal modeling of the plate heat exchanger, the effects of flow maldistribution for each side are also considered. A multi objective optimization is implemented based on the NSGA-II (Non-dominated Sorting Genetic Algorithm-II) algorithm to obtain the optimal trade-off (Pareto front) between effectiveness and pressure drop of hot side. The optimization variables in this study are considered as chevron angle, the number of plates, corrugation depth, corrugation pitch, horizontal distance of ports, vertical distance of ports, and port diameter and the goal is to achieve maximum effectiveness and minimum pressure drop. In addition, operational and geometrical constraints are also considered in the optimization procedure in order to take the advantage of the standard design and achieve feasible solutions. Next, a case study is presented to identify conflicting thermal-hydraulic behavior of plate heat exchanger. The results are reported as a set of multiple optimum solutions called ʺPareto optimal solutionsʺ. Moreover, the effect of changing these parameters on the optimal design is also presented and discussed in detail.

Experimental investigation of an absorption heat pump with organic working pairs

As part of a systematic approach towards the search for alternative absorption heat pump (AHP) working pairs that could potentially provide comparable performance to conventional ones, a previous work performed a detailed theoretical cycle analysis and simulation that revealed concrete correlations between key working fluid thermophysical properties and AHP performance indicators. Following this work, targeted combinations of two organic refrigerants, 2,2,2-trifluoroethanol (TFE) and 2,2,3,3,3-pentafluoropropanol (5FP) and two organic absorbents, 1,3-dimethyl-2-imidazolidinone (DMI) and 2-pyrrolidone (PYR) were tested in a prototype 5 kW AHP, based on a highly compact plate heat exchanger design, which has been previously introduced. The purpose of this effort was to test the findings of the previous work with experimental measurements. The working pair combinations were also subjected to vapor liquid equilibrium (VLE) and viscosity measurements, in order to determine reliable activity coefficient and improve the accuracy of the simulations. The experimental performance data agree well with the COP simulations and show to be consistent with the conclusions derived from the previous theoretical work.

Entropy Generation Minimization for the Design of Plate Heat Exchangers

Entropy Generation Minimization for the Design of Plate Heat Exchangers

Computation fluid dynamics design of a plate fin heat exchanger with different transverse vortex generators for food processing

AbstractIn this work, the performance of a plate heat exchanger with rectangular, rhombus, and elliptical vortex generators with 3, 5, and 7 mm width and 3, 6, and 9 mm height were investigated by means of computation fluid dynamics (CFD). Moreover, seven flow rates (from 0.01 to 1 ms−1) were tested and 196 CFD models were obtained. Heat transfer coefficient, pressure drop, Colburn j, and Fanning f factor were considered to evaluate the performance of the heat exchanger. The best heat exchange was obtained for rhombus wings and the highest Colburn j factor was obtained for 7 mm width and 6 mm height. The lowest pressure drop was obtained for 3 mm width and 3 mm height elliptical wings. Regarding surface reduction, the best result for all the geometries was with 5 mm width and 9 mm height, allowing a possible reduction of 25, 26, and 23% for rectangular, rhombus, and elliptical geometry.Practical applicationsPlate heat exchangers are extensively used for continuous thermal processing of liquid foods without particles in suspension and with low viscosity. In the last decades, due to the increasing demand of high quality foods and energy saving, increasing the overall heat transfer performances of food processes became crucial for the sector. Computation fluid dynamics (CFD) technique can contribute to understanding food fluid flows inside heat exchangers and in supporting equipment design. Product and process quality can be improved with minimum cost and time investment. In this work CFD was used for studying the performances of a plate heat exchanger with different passive vortex generators presenting different shapes and dimensions. The simulated data allowed identifying the best geometry with the best balance between heat performance improvements and pressure losses. The proposed approach successfully applied to Newtonian fluid could be extended also to non‐Newtonian liquid foods and to different plate heat exchanger design.

Design of plate heat exchangers for use in medium temperature organic Rankine cycles

An organic Rankine cycle (ORC) is used to efficiently recover the exhaust gas waste heat discharged from a ship. One of the crucial factors that determines the efficiency of an ORC system is the heat exchanger used in it. In this study, a plate heat exchanger is used as the heat exchanger for the evaporator and condenser in an ORC system. This is because a plate heat exchanger can achieve smaller size and higher heat transfer coefficient in contrast to the shell-and-tube heat exchanger by reducing the heat transfer area. In order to determine the heat transfer area of the evaporator and the condenser, an appropriate heat transfer correlation should be selected according to the flow path and fluid condition. Therefore, the heat transfer area of the evaporator in an ORC system is obtained by using the evaporation heat transfer correlation of Kim et al. In addition, the heat transfer area of the condenser in an ORC system is calculated using the condensation heat transfer correlation of Yan et al. From the results obtained by this simulation, the existing evaporation and condensation heat transfer coefficients in the literature are compared and analyzed.

CAE methods for plate heat exchanger design

The heat recovery can substantially reduce energy consumption needful for heating or air conditioning of buildings. The aim of work is to develop a simple CAE method for rapid design and optimization of the dimensions of plate heat exchangers for heat recovery. Flow and heat transfer in an air-to-air recuperative counter-flow plate heat exchangers were investigated numerically. Pressure drop and effectiveness were evaluated as functions of inlet velocity for three sizes of real heat exchangers. Obtained data were analyzed, inlet/outlet cross-flow and middle counter-flow parts were investigated independently and data were substituted by suggested functions for Nusselt number and loss coefficients. These functions were used to illustrate the effect of heat exchanger dimensions. It proved that bigger heat exchangers provide higher effectiveness and lower pressure drop for the same flow rate, but also the heat transfer surface is larger. Derived equations which also take the effect of material thickness and plate pitch into account represent a useful tool for design and optimization of recuperative heat exchangers for use in HVAC systems.

3D CFD fluid flow and thermal analyses of a new design of plate heat exchanger

Abstract The paper presents a Computational Fluid Dynamics (CFD) numerical study for a new design of a plate heat exchanger with two different flow patterns. The impact of geometric characteristics of the two studied geometries of exchanger plates on the intensification process of heat transfer was considered. The velocity, temperature and pressure distributions along the heat exchanger were examined. The CFD results were validated against experimental data and a good agreement was achieved. The results revealed that geometrical arrangement of the plates strongly influence the fluid flow. An increase in the Reynolds number led to lowering the friction factor value and increasing the pressure drop. The configuration II of the plate heat exchanger resulted in lower outlet hot fluid temperature in comparison with the configuration I, which means improvement of heat transfer.

Evaluation of CAE Methods Used for Plate Heat Exchanger Design

Abstract Flow and heat transfer in a plastic recuperative counter flow plate air-to-air heat exchanger were investigated experimentally and numerically using Ansys Fluent software. It was employed previously developed methods to generate a computational mesh and assumed nonzero thickness of the plates to calculate the flow in an air-to-air heat exchanger. Pressure drop and effectiveness were evaluated as functions of inlet velocity. Obtained numerical data were substituted by suggested functions dependent on the Reynolds number and later modified to take change in plate pitch and material thickness into account. It was found that change in plate pitch influence only friction losses due to change of turbulence of the flow. The shape of mini-channels, which are defined by the shape of pressing molds that are constant during our investigation, determines local loses. Increasing the plate pitch has the same effect on Nusselt number as increasing the Reynolds number. Modified functions were used to illustrate the effect of material thickness, plate pitch and heat conductivity of material on pressure drop and effectiveness. Derived equations witch take the effect of material thickness and plate pitch into account represent a useful tool for design and optimization of recuperative heat exchanger for use in HVAC systems in sustainability buildings.

Parameters Affecting the Performance of a Plate Heat Exchanger using the CFD

A plate heat exchanger is a type of heat exchangers that provides more surface area for heat transfer between two fluids. Plate heat exchangers are widely used for heat transfer applications in the industry. In addition, they are now widely used in many applications such as food processing, chemical reaction processes, heating and cooling applications in sectors such as petroleum. However, the design of plate heat exchangers is complicated by the large number of variables and geometries that affect its performance. A better heat exchanger design is to achieve a high heat transfer rate at low pumping power with low cost. In this study, the focus is on the research and development efforts of different plate materials, various fluid types, their flow regimes and the plate grooving angles on plate heat exchanger performance. For this purpose, the Computational Fluid Dynamics (CFD) is used. The results show that the heat efficiency is the best performing heat exchanger that can be designed as parallel- and counter-flow, geothermal fluid, titanium plate and 60° groove angle from the point of view.

Advanced Methods of Modelling and Design of Plate Heat Exchangers

Research of devices for heat recovery is currently focused on increasing the heat effectiveness of plate heat exchangers. The goal of optimization is not only to increase the heat transfer but also reduce the pressure loss and material costs. During the optimization of plate heat exchangers using CFD, we are struggling with the problem of how to create a quality computational mesh inside complex and irregular channels. These channels are formed by combining individual plates or blades that are shaped by molding, vacuum forming, or similar technology. Creating computational mesh from the bottom up manually is time consuming and does not help later optimization. The paper presents a new method for creating of computational meshes to simulate flow and heat transfer in a plate heat exchanger. This method is based on dynamic mesh method “user defined deforming” provided by ANSYS Fluent. The method is fast and provide applicable tool for optimization. Influences of cell size and count of layers of computational cells on heat transfer and pressure drop were investigated. It was found that the minimum number of layers is twelve across the channel, otherwise obtained data can be irrelevant.

Plate heat exchanger design software for industrial and educational applications

Plate heat exchanger is a type of heat exchanger that uses corrugated metal plates to transfer heat between two fluids. The plate corrugations are designed to achieve turbulence across the entire heat transfer area thus producing the highest possible heat transfer coefficients while allowing close temperature approaches. Subsequently, this leads to a smaller heat transfer area, smaller units and in some cases, fewer heat exchangers. In this work, an application for thermal and hydraulic computations of plate heat exchangers had been developed using Sharp Develop, an open source programming platform. During the development process, several literature methods and correlations for calculation of heat transfer coefficient and pressure drop in a plate heat exchanger have been tested and the selected four methods: Martin, VDI, Kumar and Coulson and Richardson have been incorporated into the software. The structure of the software is visually presented through several windows: a window for inserting input data, windows for showing the results of computation by each of the methods, a window for showing comparative analysis of the most important computation results obtained by all of the used methods and a help window for demonstrating the working principle of plate heat exchanger.

Thermal performance of a prototype plate heat exchanger with minichannels under boiling conditions

To solve the problem and to meet the requirements of customers in the field of high heat fluxes transfer in compact units, a new design of plate heat exchanger with minichannels (minichannels PHE) was proposed. The aim was to construct a compact heat exchanger of high effectiveness for the purpose of household cogeneration ORC system. In this paper the experimental analysis of an assembled prototype of such compact heat exchanger was described. The attention was paid to its thermal performance and the heat transfer coefficients under the boiling conditions. Water and ethanol were chosen as working fluids. The maximal value of transferred heat flux was about 84 kW/m2, while of the overall heat transfer coefficient was about 4000 W/(m2K). Estimated values of heat transfer coefficient on the ethanol (boiling) side reached the level of 7500 W/(m2K). The results are promising in the light of future applications, for example in cogeneration ORC systems, however further systematic investigations are necessary.