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Sample records for shell-and-tube heat exchanger

  1. PENGARUH PENGGUNAAN BAFFLE PADA SHELL-AND-TUBE HEAT EXCHANGER

    OpenAIRE

    Ekadewi Anggraini Handoyo

    2001-01-01

    Shell-and-tube heat exchanger is a device commonly used to transfer heat. To enhance the heat transfer occurred and to support the tubes inside the shell, baffles are installed. Better heat transfer is obviously expected in a heat exchanger. A research is done to find out the effect of baffle used toward the effectiveness and pressure drop in heat exchanger. The result is that the effectiveness increases when the baffles are installed. Effectiveness increases as the spacing between the baffle...

  2. Reliability analysis on a shell and tube heat exchanger

    Science.gov (United States)

    Lingeswara, S.; Omar, R.; Mohd Ghazi, T. I.

    2016-06-01

    A shell and tube heat exchanger reliability was done in this study using past history data from a carbon black manufacturing plant. The heat exchanger reliability study is vital in all related industries as inappropriate maintenance and operation of the heat exchanger will lead to major Process Safety Events (PSE) and loss of production. The overall heat exchanger coefficient/effectiveness (Uo) and Mean Time between Failures (MTBF) were analyzed and calculated. The Aspen and down time data was taken from a typical carbon black shell and tube heat exchanger manufacturing plant. As a result of the Uo calculated and analyzed, it was observed that the Uo declined over a period caused by severe fouling and heat exchanger limitation. This limitation also requires further burn out period which leads to loss of production. The MTBF calculated is 649.35 hours which is very low compared to the standard 6000 hours for the good operation of shell and tube heat exchanger. The guidelines on heat exchanger repair, preventive and predictive maintenance was identified and highlighted for better heat exchanger inspection and repair in the future. The fouling of heat exchanger and the production loss will be continuous if proper heat exchanger operation and repair using standard operating procedure is not followed.

  3. Effect of segmental baffles on the shell-and-tube heat exchanger effectiveness

    Directory of Open Access Journals (Sweden)

    Vukić Mića V.

    2014-01-01

    Full Text Available In this paper, the results of the experimental investigations of fluid flow and heat transfer in laboratory experimental shell-and-tube heat exchanger are presented. Shell-and-tube heat exchanger is with one pass of warm water on the shell side and two passes of cool water in tube bundle. Shell-and-tube heat exchanger is with 24x2 tubes (U-tube in triangle layout. During each experimental run, the pressure drops and the fluid temperatures on shell side, along the shell-and-tube heat exchanger (at positions defined in advance have been measured. Special attention was made to the investigation of the segmental baffles number influence of the shell-and-tube heat exchanger effectiveness.

  4. Effect of segmental baffles on the shell-and-tube heat exchanger effectiveness

    OpenAIRE

    Vukić Mića V.; Tomić Mladen A.; Živković Predrag M.; Ilić Gradimir S.

    2014-01-01

    In this paper, the results of the experimental investigations of fluid flow and heat transfer in laboratory experimental shell-and-tube heat exchanger are presented. Shell-and-tube heat exchanger is with one pass of warm water on the shell side and two passes of cool water in tube bundle. Shell-and-tube heat exchanger is with 24x2 tubes (U-tube) in triangle layout. During each experimental run, the pressure drops and the fluid temperatures on shell side, al...

  5. A SIMPLIFIED PREDICTIVE CONTROL FOR A SHELL AND TUBE HEAT EXCHANGER

    OpenAIRE

    S.RAJASEKARAN,; Dr.T.KANNADASAN

    2010-01-01

    In this paper a simplified predictive control design is applied for the controlling a temperature of a fluid stream using the shell and tube heat exchanger. The predictive control design based on Dynamic Matrix Control (DMC) involves the complicated inversion computation for higher dimensional matrix. Using DMC for controlling a temperature of the shell and tube heat exchanger, there is still a need for optimization of conversation of energy. The simplified predictive control is based on DMC,...

  6. Simulasi Performansi Heat Exchanger Type Shell And Tube Dengan Double Segmental Baffle Terhadap Helical Baffle

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    Anggareza Adhitiya

    2013-12-01

    Full Text Available Pada heat exchanger type shell and tube, selain pengunaan baffle yang bertujuan untuk mengarahkan aliran pada sisi shell juga bertujuan untuk meningkatkan laju perpindahan panas yang terjadi antara fluida kerja dengan cara menimbulkan olakan aliran di sisi shell. Olakan –olakan ini nantinya yang akan mempengaruhi besarnya perpindahan panas dalam sisi shell. Pada kondisi standart baffle yang digunakan pada tugas akhir ini adalah jenis double segmental. Double segmental baffle mempunyai tingkat pressure drop yang cukup besar. sehingga perlu di ganti dengan baffle jenis helical yang mempunyai pressure drop yang lebih kecil. Untuk mengetahui performansi heat exchanger maka perlu adanya penelitian lebih lanjut simulasi numerik pada baffle heat exchanger type shell and tube. agar didapat pengaruh jenis baffle yang di gunakan terhadap karakteristik aliran dan perpindahan panas dari suatu heat exchanger type shell and tube. Tugas Akhir ini menggunakan program GAMBIT 2.4.6 untuk penggambaran geometri secara tiga dimensi dan program FLUENT 6.3.26 untuk mensimulasi aliran yang terjadi di dalam shell and tube heat exchanger. Pada software FLUENT 6.3.26 digunakan permodelan 3D Steady Flow dengan  memilih k – Epsilon RNG sebagai turbulence modeling serta mengaktifkan persamaan energy. Penelitian dilakukan dengan menggunakan dua variasi heat exchanger dengan jenis baffle yang berbeda .Heat exchanger type shell and tube dengan jenis double segmental baffle mempunyai nilai koefisien konveksi rata-rata = 218.408 w/m2.K. Sedangkan untuk helical baffle sebesar = 171.122 w/m2.K. Temperature outflow pada heat exchanger type shell and tube dengan jenis double segmental baffle = 306.7450K. Di ikuti dengan pressure drop sebesar = 2100 pascal Sedangkan untuk helical baffle mempunyai temperatur outflow sebesar = 307.0220K dengan pressure drop sebesar = 500 pascal.

  7. Assessment of Real Heat Transfer Coefficients through Shell and Tube and Plate Heat Exchangers

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    Dan CONSTANTINESCU

    2011-07-01

    Full Text Available The purpose of this paper is to present a procedure used in the assessment of the real heat transfer characteristic of shell and tube and plate heat exchangers. The theoretical fundamentals of the procedure are introduced as well as the measured data collection and processing. The theoretical analysis is focused on the adoption of criterial equations which, subjected to certain verification criteria presented in the paper, provide the most credible value of the convection heat transfer coefficients inside the circular and flat tubes. In the end two case studies are presented, one concerning a shell and tube heat exchanger operational at INCERC Thermal Substation and the other concerning a plate heat exchanger tested on the Laboratory Stand of the Department of Building Services and Efficient Use of Energy in Buildings of INCERC Bucharest.

  8. A SIMPLIFIED PREDICTIVE CONTROL FOR A SHELL AND TUBE HEAT EXCHANGER

    Directory of Open Access Journals (Sweden)

    S.RAJASEKARAN,

    2010-12-01

    Full Text Available In this paper a simplified predictive control design is applied for the controlling a temperature of a fluid stream using the shell and tube heat exchanger. The predictive control design based on Dynamic Matrix Control (DMC involves the complicated inversion computation for higher dimensional matrix. Using DMC for controlling a temperature of the shell and tube heat exchanger, there is still a need for optimization of conversation of energy. The simplified predictive control is based on DMC, which reduces the computational complexity by exploring its internal mechanism. Finally the simplified Predictive Control is applied to shell and tube heat exchanger and the results of this control algorithm compared with the conventional PID controller and DMC based PID Controllers.

  9. Experimental investigation of shell-and-tube heat exchanger with a new type of baffles

    Science.gov (United States)

    Wang, Yingshuang; Liu, Zhichun; Huang, Suyi; Liu, Wei; Li, Weiwei

    2011-07-01

    A shell-and-tube heat exchanger with new type of baffles, is designed, fabricated and tested. The experimental investigation for the proposed model and the original segmental baffle heat exchanger are conducted. The operation performances of the two heat exchangers are also compared. The results suggest that, under the same conditions, the overall performance of the new model is 20-30% more efficient than that of the segmental baffle heat exchanger.

  10. THERMAL ANALYSIS OF SHELL AND TUBE HEAT EXCHANGER USING CFD

    OpenAIRE

    Karthikeyan. D

    2016-01-01

    In present day shell and tube heat exchanger is the most common type heat exchanger widely use in oil refinery and other large chemical process, because it suits high pressure application. The process in solving simulation consists of modeling and meshing the basic geometry of...

  11. Experimental Investigation of Heat transfer rate of Nano fluids using a Shell and Tube Heat exchanger

    Science.gov (United States)

    SIVA ESWARA RAO, M.; SREERAMULU, DOWLURU; ASIRI NAIDU, D.

    2016-09-01

    Nano fluids are used for increasing thermal properties in heat transfer equipment like heat exchangers, radiators etc. This paper investigates the heat transfer rate of Nano fluids using a shell and tube heat exchanger in single and multi tubes under turbulent flow condition by a forced convection mode. Alumina Nanoparticles are prepared by using Sol-Gel method. Heat transfer rate increases with decreasing particle size. In this experiment Alumina Nano particles of about 22 nm diameter used. Alumina Nano fluids are prepared with different concentrations of Alumina particles (0.13%, 0.27%, 0.4%, and 0.53%) with water as a base fluid using ultra-sonicator. Experiment have been conducted on shell and tube heat exchanger for the above concentrations on parallel and counter flow conditions by keeping constant inlet temperatures and mass flow rate. The result shows that the heat transfer rate is good compared to conventional fluids. The properties of Nano fluids and non-dimensional numbers have been calculated.

  12. Investigation of a twisted-tube type shell-and-tube heat exchanger

    OpenAIRE

    Danielsen, Sven Olaf

    2009-01-01

    This master thesis investigates twisted tube type shell-and-tube heat exchangers with emphasis on thermal-hydraulic characteristics, fouling and vibration properties. An extensive literature study has been carried out in order to map all published research reports written on the topic. The mapping of performed research shows that the available information is limited.Mathematical correlations for twisted tube thermal-hydraulic characteristics are extracted from the research reports found in th...

  13. Heat Transfer Enhancement of Shell and Tube Heat Exchanger Using Conical Tapes.

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    Dhanraj S.Pimple

    2014-12-01

    Full Text Available This paper provides heat transfer and friction factor data for single -phase flow in a shell and tube heat exchanger fitted with a helical tape insert. In the double concentric tube heat exchanger, hot air was passed through the inner tube while the cold water was flowed through the annulus. The influences of the helical insert on heat transfer rate and friction factor were studied for counter flow, and Nusselt numbers and friction factor obtained were compared with previous data (Dittus 1930, Petukhov 1970, Moody 1944 for axial flows in the plain tube. The flow considered is in a low Reynolds number range between 2300 and 8800. A maximum percentage gain of 165% in heat transfer rate is obtained for using the helical insert in comparison with the plain tube.

  14. PENGARUH KECEPATAN ALIRAN TERHADAP EFEKTIVITAS SHELL-AND-TUBE HEAT EXCHANGER

    OpenAIRE

    Ekadewi Anggraini Handoyo

    2000-01-01

    As a device to exchange heat from hot fluid to colder fluid, a heat exchanger is supposed to have high effectiveness. Theoretically, the increase of fluid rate would increase the effectiveness. Yet, it makes the contact time among the fluids become shorter. Based on this phenomenon, a research is carried on to find out how the fluid rate affects the effectiveness of a Shell-and-Tube Heat Exchanger. The working fluid used is air. It is found out that the effectiveness would up to a certain val...

  15. Thermal effectiveness of multiple shell and tube pass TEMA E heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Pignotti, A. (TECHNIT S.A., Buenos Aires (Argentina)); Tamborenea, P.I. (Fundacion Hermanos, Buenos Aires (Argentina))

    1988-02-01

    The thermal effectiveness of a TEMAE shell-and-tube heat exchanger, with one shell pass and an arbitrary number of tube passes, is determined under the usual simplifying assumptions of perfect transverse mixing of the shell fluid, no phase change, and temperature independence of the heat capacity rates and the heat transfer coefficient. A purely algebraic solution is obtained for the effectiveness as a functions of the heat capacity rate ratio and the number of heat transfer units. The case with M shell passes and N tube passes is easily expressed in terms of the single-shell-pass case.

  16. Flow mechanism and heat transfer enhancement in longitudinal-flow tube bundle of shell-and-tube heat exchanger

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The flow disturbance and heat transfer mechanism in the tube bundle of rod baffle shell-and-tube heat exchanger were analyzed, on the basis of which and combined with the concept of heat transfer enhancement in the core flow, a new type of shell-and-tube heat exchanger with combination of rod and van type spoiler was designed. Corresponding mathematical and physical models on the shell side about the new type heat exchanger were established, and fluid flow and heat transfer characteristics were numerically analyzed. The simulation results showed that heat transfer coefficient of the new type of heat exchanger approximated to that of rod baffle heat exchanger, but flow pressure drop was much less than the latter, indicating that comprehensive performance of the former is superior to that of the latter. Compared with rod baffle heat exchanger, heat transfer coefficient of the heat exchanger under investigation is higher under same pressure drop, especially under the high Reynolds numbers.

  17. Numerical analysis of the steam flow field in shell and tube heat exchanger

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    Bartoszewicz Jarosław

    2016-06-01

    Full Text Available In the paper, the results of numerical simulations of the steam flow in a shell and tube heat exchanger are presented. The efficiency of different models of turbulence was tested. In numerical calculations the following turbulence models were used: k-ε, RNG k-ε, Wilcox k-ω, Chen-Kim k-ε, and Lam-Bremhorst k-ε. Numerical analysis of the steam flow was carried out assuming that the flow at the inlet section of the heat exchanger were divided into three parts. The angle of steam flow at inlet section was determined individually in order to obtain the best configuration of entry vanes and hence improve the heat exchanger construction. Results of numerical studies were verified experimentally for a real heat exchanger. The modification of the inlet flow direction according to theoretical considerations causes the increase of thermal power of a heat exchanger of about 14%.

  18. Numerical analysis of the steam flow field in shell and tube heat exchanger

    Science.gov (United States)

    Bartoszewicz, Jarosław; Bogusławski, Leon

    2016-06-01

    In the paper, the results of numerical simulations of the steam flow in a shell and tube heat exchanger are presented. The efficiency of different models of turbulence was tested. In numerical calculations the following turbulence models were used: k-ɛ, RNG k-ɛ, Wilcox k-ω, Chen-Kim k-ɛ, and Lam-Bremhorst k-ɛ. Numerical analysis of the steam flow was carried out assuming that the flow at the inlet section of the heat exchanger were divided into three parts. The angle of steam flow at inlet section was determined individually in order to obtain the best configuration of entry vanes and hence improve the heat exchanger construction. Results of numerical studies were verified experimentally for a real heat exchanger. The modification of the inlet flow direction according to theoretical considerations causes the increase of thermal power of a heat exchanger of about 14%.

  19. Velocity profiles between two baffles in a shell and tube heat exchanger

    Science.gov (United States)

    Chang, Tae-Hyun; Lee, Chang-Hoan; Lee, Hae-Soo; Lee, Kwon-Soo

    2015-06-01

    Heat exchangers are extensively utilized for waste heat recovery, oil refining, chemical processing, and steam generation. In this study, velocity profiles are measured using a 3D particle image velocimetry (PIV) system betweentwo baffles in a shell and tube heat exchanger for parallel and counter flows. The PIV and computational fluid dynamics results show the occurrence of some strong vectors near the bottom. These vectors are assumed due to the clearance between the inner tubes and the front baffle. Therefore, the major parts of the vectors are moved out through the bottom opening of the rear baffle, and other vectors produce a large circle between the two baffles. Numerical simulations are conducted to investigate the effects of the baffle on the heat exchanger using the Fluent software. The k-ɛ turbulence model is employed to calculate the flows along the heat exchanger

  20. Performance tests of the 1MWt shell-and-tube heat exchangers for OTEC

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, A.; Lorenz, J. J.; Hillis, D. L.; Yung, D. T.; Sather, N. P.

    1979-01-01

    Final test results are reported for the five 1 MWt shell-and-tube heat exchangers tested at Argonne National Laboratory. These five heat exchangers are the Union Carbide flooded-bundle evaporator, the Union Carbide sprayed-bundle evaporator, the Union Carbide enhanced-tube condenser, the Carnegie-Mellon vertical fluted-tube evaporator, and the Carnegie-Mellon vertical fluted-tube condenser. Performance parameters measured include the overall heat transfer coefficient (U/sub 0/), the water-side pressure drop, and the vapor quality. Also measured were operational characteristics of the heat exchangers such as repeatability of results and the dependence of U/sub 0/ on heat duty, ammonia flow rate, and subcooling. Individual water-side and ammonia-side coefficients were deduced using the Wilson Plot method.

  1. Melting of Nanoprticle-Enhanced Phase Change Material inside Shell and Tube Heat Exchanger

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    Seiyed Mohammad Javad Hosseini

    2013-01-01

    Full Text Available This paper presents a numerical study of melting of Nanoprticle-Enhanced phase change material (NEPCM inside a shell and tube heat exchanger using RT50 and copper particles as base material and nanoparticle, respectively. In this study, the effects of nanoparticles dispersion (, 0.03, and 0.05 on melting time, liquid fraction, and penetration length are investigated. The results show that the melting time decreases to 14.6% and the penetration length increases to 146% with increasing volume fraction of nanoparticle up to .

  2. Numerical Investigation on Double Shell-Pass Shell-and-Tube Heat Exchanger with Continuous Helical Baffles

    OpenAIRE

    Shui Ji; Wen-jing Du; Peng Wang; Lin Cheng

    2011-01-01

    A double shell-pass shell-and-tube heat exchanger with continuous helical baffles (STHXCH) has been invented to improve the shell-side performance of STHXCH. At the same flow area, the double shell-pass STHXCH is compared with a single shell-pass STHXCH and a conventional shell-and-tube heat exchanger with segmental baffles (STHXSG) by means of numerical method. The numerical results show that the shell-side heat transfer coefficients of the novel heat exchanger are 12–17% and 14–25% higher t...

  3. Experimental Investigation on Heat Transfer and Frictional Characteristics of Shell-and-tube Heat exchangers with Different Baffles and Tubes

    Science.gov (United States)

    Wang, C.; Zhu, J. G.; Sang, Z. F.

    2010-03-01

    In this study, the heat transfer and tube frictional characteristics of the helixchangers (shell-and-tube heat exchanger with helical baffles) with spirally corrugated and smooth tubes and the conventional shell-and-tube heat exchanger with smooth tubes were experimentally obtained. The results show that the helixchangers with the spirally corrugated tube and the smooth tubes enhance the total heat transfer coefficient about 26% and 7% on the average than the segmental baffled heat exchanger. In the tube side, the spirally corrugated tube leads to about 28% average increase on convective heat transfer performance and about 24% average increase on pressure drop than the smooth tube, but its conversion efficiency is still higher. The helical baffle could enhance the shell-side condensation coefficient by 13%, and the spirally corrugated tube could help the helixchanger with it enhance remarkably the condensation performance by 53% than the segmental baffled heat exchanger.

  4. Performance evaluation of a shell and tube heat exchanger operated with oxide based nanofluids

    Science.gov (United States)

    Shahrul, I. M.; Mahbubul, I. M.; Saidur, R.; Khaleduzzaman, S. S.; Sabri, M. F. M.

    2016-08-01

    This study is about the performance evaluation of a shell and tube heat exchanger operated with nanofluid. Thermal conductivity, viscosity, and density of the nanofluids were increased, but the specific heat of the nanofluids was decreased with increasing the concentrations of the particles. The convective heat transfer coefficient was found to be 2-15 % higher than that of water at 50 kg/min of both side fluid. Nevertheless, energy effectiveness has improved about 23-52 % for the above-mentioned nanofluids. As, energy effectiveness (ɛ) is strongly depends on the density and specific heat of the operating fluids therefore, maximum ɛ has obtained for ZnO-W nanofluid and lowest found for SiO2-W nanofluid.

  5. 3D NUMERICAL SIMULATIONS OF THE THERMAL PROCESSES IN THE SHELL AND TUBE HEAT EXCHANGER

    Directory of Open Access Journals (Sweden)

    Mića V. Vukić

    2014-01-01

    Full Text Available A shell and tube heat exchanger (STHE is one of the most often used apparatuses in chemical industry. One of the main goals of the STHE manufacturers is to improve their exploitation reliability and efficiency. Two approaches to the STHE design improvement are possible: experimental investigation, which is very expensive and time-consuming because of the shell side complex geometry, and numerical investigations. Numerical simulations can be used to check the old and to develop new and more efficient STHE designs. In this paper, the results of the numerical investigations of fluid flow and heat transfer in the laboratory experimental STHE are presented. Numerical simulation has been performed by using the PHOENICS code. The tube bundle has been modeled by using the concept of porous media. Standard k-e turbulence model is used.

  6. Experimental performance investigation of a shell and tube heat exchanger by exergy based sensitivity analysis

    Science.gov (United States)

    Mert, Suha Orçun; Reis, Alper

    2016-06-01

    Heat exchangers are used extensively in many industrial branches, primarily so in chemical and energy sectors. They also have important household usage as they are used in central and local heating systems. Any betterment on heat exchangers will serve greatly in preserving our already dwindling and costly energy resources. Strong approach of exergy analysis -which helps find out where the first steps should be taken in determining sources of inefficiencies and how to remedy them- will be used as a means to this end. The maximum useful work that can be harnessed from systems relationships with its environment is defined as exergy. In this study, the inlet and outlet flow rate values of fluids and temperature of hot stream both on shell and tube parts of a shell-tube heat exchange system have been inspected and their effects on the exergy efficiency of this thermal system have been analyzed. It is seen that the combination of high tube side inlet temperature, low shell side flow rate and high tube side flow rate are found to be the optimum for this experimental system with reaching 75, 65, and 32 % efficiencies respectively. Selecting operating conditions suitable to this behavior will help to increase the overall efficiency of shell-tube heat exchange systems and cause an increment in energy conservation.

  7. Prediction of Heat Transfer Rates for Shell-and-Tube Heat Exchangers by Artificial Neural Networks Approach

    Institute of Scientific and Technical Information of China (English)

    Qiuwang WANG; Gongnan XIE; Ming ZENG; Laiqin LUO

    2006-01-01

    This work used artificial neural network (ANN) to predict the heat transfer rates of shell-and-tube heat exchangers with segmental baffles or continuous helical baffles, based on limited experimental data. The Back Propagation (BP) algorithm was used in training the networks. Different network configurations were also studied. The deviation between the predicted results and experimental data was less than 2%. Comparison with correlation for prediction shows ANN superiority. It is recommended that ANN can be easily used to predict the performances of thermal systems in engineering applications, especially to model heat exchangers for heat transfer analysis.

  8. Experimental Study on Heat Transfer Characteristics of Shell and Tube Heat Exchanger Using Hitran Wire Matrix Turbulators As Tube Inserts.

    Directory of Open Access Journals (Sweden)

    Manoj

    2014-06-01

    Full Text Available Shell and tube heat exchangers are extensively used in boilers, oil coolers, pre-heaters, condensers etc. They are also having special importance in process application as well as refrigeration and air conditioning industries. The present paper emphasizes on heat transfer characteristics of shell and tube heat exchangers with the aid of hiTRAN wire matrix inserts is been studied. Investigations were made on effect of mass flow rate of water on heat transfer characteristics in case of plain tube without inserts. When hiTRAN wire matrix tube inserts are used, which effectively increases the turbulence of tube side flow due to the hydrodynamic and thermal agitation of boundary layer in turns increases additional pressure drop is available in the system. This results in increase in the wall shear, reduced wall temperature which enhances substantial increase in tube side heat transfer characteristics. Heat and cooling processes streams is a standard operation in many industries this operation is often performed in heat exchangers where the heated or cold fluid flows under laminar conditions inside the tubes the mechanisms of under those flow conditions are complex poorly understood since they can involve both forced and natural convection making accurate prediction for heat exchanger. Heat transfer in laminar flow regimes is low by default but can be greatly increased by the use of passive heat transfer enhancement such as tube inserts. The present analysis the hiTRAN wire matrix turbulators were used and increased heat transfer characteristics as expected outcomes.

  9. Fundamental basis and implementation of shell and tube heat exchanger project design: condenser and evaporator study

    Science.gov (United States)

    Dalkilic, A. S.; Acikgoz, O.; Tapan, S.; Wongwises, S.

    2016-12-01

    A shell and tube heat exchanger is used as a condenser and an evaporator in this theoretical study. Parametric performance analyses for various actual refrigerants were performed using well-known correlations in open sources. Condensation and evaporation were occurred in the shell side while the water was flowing in the tube side of heat exchanger. Heat transfer rate from tube side was kept constant for condenser and evaporator design. Condensing temperatures were varied from 35 to 60 °C whereas evaporating temperatures were ranging from -15 to 10 °C for the refrigerants of R12, R22, R134a, R32, R507A, R404A, R502, R407C, R152A, R410A and R1234ZE. Variation of convective heat transfer coefficients of refrigerants, total heat transfer coefficients with Reynolds numbers and saturation temperatures were given as validation process considering not only fouling resistance and omission of it but also staggered (triangular) and line (square) arrangements. The minimum tube lengths and necessary pumping powers were calculated and given as case studies for the investigated refrigerants considering validation criteria. It was understood that refrigerant type, fouling resistance and arrangement type are one of the crucial issues regarding the determination of heat exchanger's size and energy consumption. Consequently, R32 and R152a were found to require the shortest tube length and lowest pumping power in the condenser, whereas R507 and R407C have the same advantages in the evaporator. Their heat transfer coefficients were also determined larger than others as expectedly.

  10. Design and economic investigation of shell and tube heat exchangers using Improved Intelligent Tuned Harmony Search algorithm

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    Oguz Emrah Turgut

    2014-12-01

    Full Text Available This study explores the thermal design of shell and tube heat exchangers by using Improved Intelligent Tuned Harmony Search (I-ITHS algorithm. Intelligent Tuned Harmony Search (ITHS is an upgraded version of harmony search algorithm which has an advantage of deciding intensification and diversification processes by applying proper pitch adjusting strategy. In this study, we aim to improve the search capacity of ITHS algorithm by utilizing chaotic sequences instead of uniformly distributed random numbers and applying alternative search strategies inspired by Artificial Bee Colony algorithm and Opposition Based Learning on promising areas (best solutions. Design variables including baffle spacing, shell diameter, tube outer diameter and number of tube passes are used to minimize total cost of heat exchanger that incorporates capital investment and the sum of discounted annual energy expenditures related to pumping and heat exchanger area. Results show that I-ITHS can be utilized in optimizing shell and tube heat exchangers.

  11. Design of shell-and-tube heat exchangers when the fouling depends on local temperature and velocity

    Energy Technology Data Exchange (ETDEWEB)

    Butterworth, D. [HTFS, Hyprotech, Didcot (United Kingdom)

    2002-07-01

    Shell-and-tube heat exchangers are normally designed on the basis of a uniform and constant fouling resistance that is specified in advance by the exchanger user. The design process is then one of determining the best exchanger that will achieve the thermal duty within the specified pressure drop constraints. It has been shown in previous papers [Designing shell-and-tube heat exchangers with velocity-dependant fouling, 34th US national Heat Transfer Conference, 20-22 August 2000, Pittsburg, PA; Designing shell-and-tube heat exchangers with velocity-dependant fouling, 2nd Int. Conf. on Petroleum and Gas Phase Behavior and Fouling, 27-31 August 2000, Copenhagen] that this approach can be extended to the design of exchangers where the design fouling resistance depends on velocity. The current paper briefly reviews the main findings of the previous papers and goes on to treat the case where the fouling depends also on the local temperatures. The Ebert-Panchal [Analysis of Exxon crude-oil, slip-stream coking data, Engineering Foundation Conference on Fouling Mitigation of Heat Exchangers, 18-23 June 1995, California] form of fouling rate equation is used to evaluate this fouling dependence. When allowing for temperature effects, it becomes difficult to divorce the design from the way the exchanger will be operated up to the point when the design fouling is achieved. However, rational ways of separating the design from the operation are proposed. (author)

  12. A new optimization approach for shell and tube heat exchangers by using electromagnetism-like algorithm (EM)

    Science.gov (United States)

    Abed, Azher M.; Abed, Issa Ahmed; Majdi, Hasan Sh.; Al-Shamani, Ali Najah; Sopian, K.

    2016-12-01

    This study proposes a new procedure for optimal design of shell and tube heat exchangers. The electromagnetism-like algorithm is applied to save on heat exchanger capital cost and designing a compact, high performance heat exchanger with effective use of the allowable pressure drop (cost of the pump). An optimization algorithm is then utilized to determine the optimal values of both geometric design parameters and maximum allowable pressure drop by pursuing the minimization of a total cost function. A computer code is developed for the optimal shell and tube heat exchangers. Different test cases are solved to demonstrate the effectiveness and ability of the proposed algorithm. Results are also compared with those obtained by other approaches available in the literature. The comparisons indicate that a proposed design procedure can be successfully applied in the optimal design of shell and tube heat exchangers. In particular, in the examined cases a reduction of total costs up to 30, 29, and 56.15 % compared with the original design and up to 18, 5.5 and 7.4 % compared with other approaches for case study 1, 2 and 3 respectively, are observed. In this work, economic optimization resulting from the proposed design procedure are relevant especially when the size/volume is critical for high performance and compact unit, moderate volume and cost are needed.

  13. Vibration analysis of shell-and-tube heat exchangers: an overview-Part 2: vibration response, fretting-wear, guidelines

    Science.gov (United States)

    Pettigrew, M. J.; Taylor, C. E.

    2003-11-01

    Design guidelines were developed to prevent tube failures due to excessive flow-induced vibration in shell-and-tube heat exchangers. An overview of vibration analysis procedures and recommended design guidelines is presented in this paper. This paper pertains to liquid, gas and two-phase heat exchangers such as nuclear steam generators, reboilers, coolers, service water heat exchangers, condensers, and moisture-separator-reheaters. Part 2 of this paper covers forced vibration excitation mechanisms, vibration response prediction, resulting damage assessment, and acceptance criteria.

  14. Design and Development of Shell and Tube Heat Exchanger for Harar Brewery Company Pasteurizer Application (Mechanical and Thermal Design)

    OpenAIRE

    Dawit Bogale

    2014-01-01

    A heat exchanger is a device that is used to transfer thermal energy (enthalpy) between two or more fluids, between a solid surface and a fluid, or between solid particulates and a fluid, at different temperatures and in thermal contact[1].From different types of heat exchangers the shell and tube heat exchangers with straight tubes and single pass is to be under study. Here the redesign takes place because of temperature fluctuation at the 9th zone of the pasteurizer in the Harar Brewery Co...

  15. Shell side numerical analysis of a shell and tube heat exchanger considering the effects of baffle inclination angle on fluid flow using CFD

    OpenAIRE

    Raj Karuppa Thundil R.; Ganne Srikanth

    2012-01-01

    In this present study, attempts were made to investigate the impacts of various baffle inclination angles on fluid flow and the heat transfer characteristics of a shell-and-tube heat exchanger for three different baffle inclination angles namely 0°,10° and 20°. The simulation results for various shell and tube heat exchangers, one with segmental baffles perpendicular to fluid flow and two with segmental baffles inclined to the direction of fluid flow are compared for their performance. ...

  16. Determination Global Heat Transfer Coefficient in Shell and Tube Type and Plates Heat Exchangers

    OpenAIRE

    Duarte, José Arnaldo

    2012-01-01

    The literature on heat exchangers is very wide because of numerous existing configurations, several types of fluids used, as well as the variety of applications. On the other hand, when we need to calculate a heat exchanger, a similar procedure is hardly found. Therefore, we propose this educational work in order to facilitate the calculation procedures, when the student or the professional in the area needs a script for its design. The heat exchanger is installed in the Laboratory of Thermal...

  17. Numerical Investigation on Double Shell-Pass Shell-and-Tube Heat Exchanger with Continuous Helical Baffles

    Directory of Open Access Journals (Sweden)

    Shui Ji

    2011-01-01

    Full Text Available A double shell-pass shell-and-tube heat exchanger with continuous helical baffles (STHXCH has been invented to improve the shell-side performance of STHXCH. At the same flow area, the double shell-pass STHXCH is compared with a single shell-pass STHXCH and a conventional shell-and-tube heat exchanger with segmental baffles (STHXSG by means of numerical method. The numerical results show that the shell-side heat transfer coefficients of the novel heat exchanger are 12–17% and 14–25% higher than those of STHXSG and single shell-pass STHXCH, respectively; the shell-side pressure drop of the novel heat exchanger is slightly lower than that of STHXSG and 29–35% higher than that of single shell-pass STHXCH. Analyses of shell-side flow field show that, under the same flow rate, double shell-pass STHXCH has the largest shell-side volume average velocity and the most uniform velocity distribution of the three STHXs. The shell-side helical flow pattern of double shell-pass STHXCH is more similar to longitudinal flow than that of single shell-pass STHXCH. Its distribution of fluid mechanical energy dissipation is also uniform. The double shell-pass STHXCH might be used to replace the STHXSG in industrial applications to save energy, reduce cost, and prolong the service life.

  18. Optimization of a Finned Shell and Tube Heat Exchanger Using a Multi-Objective Optimization Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Heidar Sadeghzadeh

    2015-08-01

    Full Text Available Heat transfer rate and cost significantly affect designs of shell and tube heat exchangers. From the viewpoint of engineering, an optimum design is obtained via maximum heat transfer rate and minimum cost. Here, an analysis of a radial, finned, shell and tube heat exchanger is carried out, considering nine design parameters: tube arrangement, tube diameter, tube pitch, tube length, number of tubes, fin height, fin thickness, baffle spacing ratio and number of fins per unit length of tube. The “Delaware modified” technique is used to determine heat transfer coefficients and the shell-side pressure drop. In this technique, the baffle cut is 20 percent and the baffle ratio limits range from 0.2 to 0.4. The optimization of the objective functions (maximum heat transfer rate and minimum total cost is performed using a non-dominated sorting genetic algorithm (NSGA-II, and compared against a one-objective algorithm, to find the best solutions. The results are depicted as a set of solutions on a Pareto front, and show that the heat transfer rate ranges from 3517 to 7075 kW. Also, the minimum and maximum objective functions are specified, allowing the designer to select the best points among these solutions based on requirements. Additionally, variations of shell-side pressure drop with total cost are depicted, and indicate that the pressure drop ranges from 3.8 to 46.7 kPa.

  19. Vibration analysis of shell-and-tube heat exchangers: an overview-Part 1: flow, damping, fluidelastic instability

    Science.gov (United States)

    Pettigrew, M. J.; Taylor, C. E.

    2003-11-01

    Design guidelines were developed to prevent tube failures due to excessive flow-induced vibration in shell-and-tube heat exchangers. An overview of vibration analysis procedures and recommended design guidelines is presented in this paper. This paper pertains to liquid, gas and two-phase heat exchangers such as nuclear steam generators, reboilers, coolers, service water heat exchangers, condensers, and moisture-separator-reheaters. Generally, a heat exchanger vibration analysis consists of the following steps: (i) flow distribution calculations, (ii) dynamic parameter evaluation (i.e. damping, effective tube mass, and dynamic stiffness), (iii) formulation of vibration excitation mechanisms, (iv) vibration response prediction, and (v) resulting damage assessment (i.e., comparison against allowables). The requirements applicable to each step are outlined in this paper. Part 1 of this paper covers flow calculations, dynamic parameters and fluidelastic instability.

  20. Two-phase experimental heat transfer studies on a water-diesel system in a shell and tube heat exchanger

    Directory of Open Access Journals (Sweden)

    V. Alagesan

    2012-06-01

    Full Text Available Two-phase heat transfer involving two immiscible systems is gaining importance in petrochemical and allied industries. Varying compositions of diesel and water were experimentally studied in a 1:2 shell and tube heat exchanger. The data on pure water and diesel were fitted to an equation of the form. h1φ = a NmRe.The two-phase multiplier, Φ L, was related to the Lockhart Martinelli (L-M parameter, χtt², using the two-phase data and a correlation Φ L = b+c(χtt²+d/(χtt²² was established. The two-phase heat transfer coefficient was calculated based on the coefficients 'a' and 'm' for pure diesel and pure water along with ФL and the L-M parameter. The calculated values of the two-phase heat transfer coefficient h2φ based on pure diesel and pure water suggest that diesel is a better reference fluid since the average error is much smaller compared to pure water as reference.

  1. Thermal-economic multi-objective optimization of shell and tube heat exchanger using particle swarm optimization (PSO)

    Science.gov (United States)

    Ghanei, A.; Assareh, E.; Biglari, M.; Ghanbarzadeh, A.; Noghrehabadi, A. R.

    2014-10-01

    Many studies are performed by researchers about shell and tube heat exchanger (STHE) but the multi-objective particle swarm optimization (PSO) technique has never been used in such studies. This paper presents application of thermal-economic multi-objective optimization of STHE using PSO. For optimal design of a STHE, it was first thermally modeled using e-number of transfer units method while Bell-Delaware procedure was applied to estimate its shell side heat transfer coefficient and pressure drop. Multi objective PSO (MOPSO) method was applied to obtain the maximum effectiveness (heat recovery) and the minimum total cost as two objective functions. The results of optimal designs were a set of multiple optimum solutions, called `Pareto optimal solutions'. In order to show the accuracy of the algorithm, a comparison is made with the non-dominated sorting genetic algorithm (NSGA-II) and MOPSO which are developed for the same problem.

  2. Beneficial design of unbaffled shell-and-tube heat exchangers for attachment of longitudinal fins with trapezoidal profile

    Directory of Open Access Journals (Sweden)

    Balaram Kundu

    2015-03-01

    Full Text Available A parametric variation followed with Kern’s method of design of extended surface heat exchanger has been made for an unbaffled shell-and-tube heat exchanger problem. For this analysis, the rectangular and trapezoidal fin shapes longitudinally attached to the fin tubes are taken. In comparison with the attachment of trapezoidal fins, it is found that the heat transfer rate was lesser than the rectangular cross section by keeping a constant outer diameter of the shell along with all other constraints of a heat exchanger design, namely, number of passes, tube outer diameter, tube pitch layout, etc. But when the total volume of the fin over a tube was kept constraint, using trapezoidal fins the heat transfer rate is found to be increased and consequently the pressure drop decreases much more than in the case of fins with rectangular cross section. This optimization has shown beneficial results in all the cases of different constraints of heat exchanger design analysis.

  3. 管壳式换热器研究进展%Research on the Progress of Shell and Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    张勇; 闫媛媛; 杨飞

    2012-01-01

    指出了传统单弓形管壳式换热器存在的缺点,分别从强化传热和优化壳程压降两个方匾论述了管壳式换热器的研究进展,并对备类强化传热和优化压降的机理做了介绍,最后提出了一种新型复合管壳式换热器的理念,为管壳式换热器的研究与发展提供依据。%Pointed out the shortcomings of traditional single segment shell and tube heat exchanger, discussed the advance research of the shell and tube heat exchanger from two aspects of the heat transfer enhancement and shell side pressure drop optimization respectively, and introduced the mechanism of various heat transfer enhancement and pressure drop optimization, and finally put forward a kind of concept of a new composite shell and tube heat exchanger for underling the research and development of the shell and tube heat exchanger.

  4. Estimated Outlet Temperatures in Shell-and-Tube Heat Exchanger Using Artificial Neural Network Approach Based on Practical Data

    Directory of Open Access Journals (Sweden)

    Hisham Hassan Jasim

    2013-01-01

    Full Text Available The objective of this study is to apply Artificial Neural Network for heat transfer analysis of shell-and-tube heat exchangers widely used in power plants and refineries. Practical data was obtained by using industrial heat exchanger operating in power generation department of Dura refinery. The commonly used Back Propagation (BP algorithm was used to train and test networks by divided the data to three samples (training, validation and testing data to give more approach data with actual case. Inputs of the neural network include inlet water temperature, inlet air temperature and mass flow rate of air. Two outputs (exit water temperature to cooling tower and exit air temperature to second stage of air compressor were taken in ANN.150 sets of data were generated in different days by the reference heat exchanger model to training the network. Regression between desired target and prediction ANN output for training , validation, testing and all samples show reasonably values are equal to one (R=1 . 50 sets of data were generated to test the network and compare between desired and predicated exit temperature (water temp. and air temp. show a good agreement ( .

  5. Investigation of the effects of baffle orientation, baffle cut and fluid viscosity on shell side pressure drop and heat transfer coefficient in an e-type shell and tube heat exchanger

    OpenAIRE

    Mohammadi, Koorosh

    2011-01-01

    The commercial CFD code FLUENT is used to determine the effect of baffle orientation and baffle cut as well as viscosity of the working fluid on the shell-side heat transfer and pressure drop of a shell and tube heat exchanger. The shell and tube heat exchangers considered follow the TEMA standards. The investigation has been completed in three stages: 1. The shell and tube heat exchanger consists of 660 plain tubes with fixed outside diameter which are arranged in a triangular layout. Hor...

  6. 管壳式换热器壳程的传热强化%Heat Transfer Enhancement in Shell Side of Shell and Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    李若兰; 丁杰; 霍正齐

    2014-01-01

    This article described heat transfer enhancement technology in shell side of the shell and tube heat ex-changer, sketched a typical structure and performance of shell side of heat exchanger, analyzed heat transfer en-hancement mechanism.%本文介绍管壳式换热器壳程的强化传热技术,简述换热器壳程的典型结构、性能,分析强化传热机理。

  7. Solid-particle erosion in the tube end of the tube sheet of a shell-and-tube heat exchanger

    Science.gov (United States)

    Habib, M. A.; Badr, H. M.; Said, S. A. M.; Ben-Mansour, R.; Al-Anizi, S. S.

    2006-03-01

    Erosion is one of the major problems in many industrial processes, and in particular, in heat exchangers. The effects of flow velocity and sand particle size on the rate of erosion in a typical shell-and-tube heat exchanger were investigated numerically using the Lagrangian particle-tracking method. Erosion and penetration rates were obtained for sand particles of diameters ranging from 10 to 500 μm and for inlet flow velocities ranging from 0.197 to 2.95 m/s. A flow visualization experiment was conducted with the objective of verifying the accuracy of the continuous phase calculation procedure. Comparison with available experimental data of penetration rates was also conducted. These comparisons resulted in a good agreement. The results show that the location and number of eroded tubes depend mainly on the particle size and velocity magnitude at the header inlet. The rate of erosion depends exponentially on the velocity. The particle size shows negligible effect on the erosion rate at high velocity values and the large-size particles show less erosion rates compared to the small-size particles at low values of inlet flow velocities. The results indicated that the erosion and penetration rates are insignificant at the lower end of the velocity range. However, these rates were found to increase continuously with the increase of the inlet flow velocity for all particle sizes. The particle size creating the highest erosion rate was found to depend on the flow velocity range.

  8. The effects of geometry and adjacent regenerators on shell-and-tube heat exchangers in oscillating flows

    Science.gov (United States)

    Brady, John Feurman

    An experimental study into the effects of geometry and the presence of adjacent screens on the acoustic impedances and heat transfer performance of shell-and-tube heat exchangers in oscillating flow was conducted. Measurements of linear and nonlinear acoustic impedances were conducted simultaneously with heat transfer measurements. The results showed that rounded tube-ends produce less nonlinear resistance than flat tube-ends. A stack of screens placed adjacent to an exchanger results in nonlinear resistances that are within 5% of those that result when no adjacent screens are used. The screens also act to reduce the drop in the inertance of the exchanger at higher displacements. The length of the exchanger was found to influence the amount of nonlinear acoustic resistance. Correlations for this effect were found, but the cause is unknown. Heat transfer measurements showed that the aspect ratio of the exchanger tubes (the ratio of length to diameter) is an important parameter in predicting heat transfer. The presence of adjacent screens increases this effect. Correlations including these effects were found. It was found that when screens were placed adjacent to an exchanger, the heat transfer effectiveness dropped by as much as 20%. Likewise, when the ends of the exchanger tubes were rounded (instead of flat) effectiveness dropped by as much as 25% again. Sudden increases in effectiveness were observed at higher frequencies and displacements. It was found that these increases correspond to the onset of turbulent bursts during velocity peaks. Application of the Chilton and Colburn-J Factor analogy to oscillating flows was also investigated. It was found that at higher friction factors the analogy did not hold. Some agreement may exist at lower friction factors; however, there is insufficient data within this range to derive reliable correlations. Comparisons between measurements and the heat exchanger model in the TX segment of the DeltaEC software package were made

  9. Shell side numerical analysis of a shell and tube heat exchanger considering the effects of baffle inclination angle on fluid flow using CFD

    Directory of Open Access Journals (Sweden)

    Raj Karuppa Thundil R.

    2012-01-01

    Full Text Available In this present study, attempts were made to investigate the impacts of various baffle inclination angles on fluid flow and the heat transfer characteristics of a shell-and-tube heat exchanger for three different baffle inclination angles namely 0°,10° and 20°. The simulation results for various shell and tube heat exchangers, one with segmental baffles perpendicular to fluid flow and two with segmental baffles inclined to the direction of fluid flow are compared for their performance. The shell side design has been investigated numerically by modeling a small shell-and-tube heat exchanger. The study is concerned with a single shell and single side pass parallel flow heat exchanger. The flow and temperature fields inside the shell are studied using non-commercial CFD software tool ANSYS CFX 12.1. For a given baffle cut of 36 %, the heat exchanger performance is investigated by varying mass flow rate and baffle inclination angle. From the CFD simulation results, the shell side outlet temperature, pressure drop, recirculation near the baffles, optimal mass flow rate and the optimum baffle inclination angle for the given heat exchanger geometry are determined.

  10. Research Progress in Heat Transfer Enhancement Technology of Shell and Tube Heat Exchangers%管壳式换热器强化传热进展

    Institute of Scientific and Technical Information of China (English)

    张轮亭; 邱丽灿; 王臣

    2014-01-01

    管壳式换热器在石油化工领域应用广泛,其强化传热技术的研究受到普遍关注。主要介绍了近年来国内与国外高效节能管壳式换热器强化传热技术研究的进展情况,分别从管侧、壳侧和整体结构改进三方面分析了管壳式换热器的强化传热效果及特点,最后提出了强化传热的发展方向。%The tube and shell heat exchanger is widely used in the petrochemical field; research on the heat transfer enhancement technology is widely concerned. In this paper, research progress in the heat transfer enhancement technology of high efficiency shell and tube heat exchangers was introduced. From three aspects of the tube side, the shell side and the overall improvement, effect and features of the heat transfer enhancement of shell and tube heat exchangers were analyzed. At last, the development direction of the enhanced heat transfer technology was put forward.

  11. 结垢对管壳式换热器流动换热影响研究%Effect of Scaling on Flow and Heat Exchange Characteristics of Shell-and-Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    吴国忠; 林林; 杨显志; 齐晗兵; 李栋

    2014-01-01

    In view of the heat transfer problem after scaling of shell-and-tube heat exchanger, the simplified mathematical and three dimensional physical model of shell-and-tube heat exchanger was established. Using the finite volume method combined with wall function method, flow and heat transfer in shell-and-tube heat exchanger were numerically simulated. The results showed that, amount of dirt inside the shell-and-tube heat exchanger had a great influence on the heat transfer process. With the scale increased, the pressure drop of scale side import and export increased and the heat exchange character reduced.%针对管壳式换热器结垢中涉及到的传热问题,建立了管壳式换热器三维的简化数理模型,采用有限体积法结合壁面函数法对管壳式换热器内流动传热过程进行数值模拟。研究结果表明,污垢量对管壳式换热器内流动传热过程影响较大,结垢量增加,结垢侧进出口压降增加,换热性能降低。

  12. Development of Design Software for Shell and Tube Heat Exchanger%管壳式换热器设计软件的开发

    Institute of Scientific and Technical Information of China (English)

    孙琪; 李贝贝

    2012-01-01

    In order to improve efficiency of the shell and tube heat exchanger design, using VB programming language as a platform, based on heat transfer performance index of the shell-side of heat exchanger, the calculation software of the shell and tube heat exchanger is designed. Users can use the software not only to design a series of national standard of segmental baffle heat exchanger structure which meet the requirements of heat exch-anger and provided certain safety factor of pressure drop conditions; but also can design anew type of helical baffles heat exchanger. Software have high accuracy, can be used for engineering design and similar software development reference.%为提高管壳式换热器设计效率,以VB程序语言为平台,基于换热器壳侧传热性能指标,设计开发了管壳式换热器计算软件.用户通过使用软件既可设计出满足给定换热量要求、规定压降条件的一系列国家标准弓行板式换热器结构;又可设计新型螺旋折流板换热器.软件计算准确性较高,可供工程设计及类似软件开发借鉴.

  13. Flow mechanism and heat transfer enhancement in longitudinal-flow tube bundle of shell-and-tube heat exchanger

    Institute of Scientific and Technical Information of China (English)

    LIU Wei; LIU ZhiChun; WANG YingShuang; HUANG SuYi

    2009-01-01

    ormer is superior to that of the latter.Compared with rod baffle heat exchanger,heat transfer coefficient of the heat exchanger under investigation is higher under same pressure drop,especially under the high Reynolds numbers.

  14. Optimizing Design for Shell and Tube Heat Exchanger Based on MATLAB%基于MATLAB的管壳式换热器优化设计

    Institute of Scientific and Technical Information of China (English)

    王雷; 蒋宁

    2012-01-01

    基于MATLAB 7.6开发了管壳式换热器,充分利用压降优化设计软件.通过改变换热器结构,充分利用管壳程压降,提高传热系数,减少换热面积.通过案例分析表明,充分利用压降后,换热器的传热系数提高了21%,换热面积减小了20%,大大减少了换热器的投资费用.%Making best use of pressure drop, the paper developed an optimizing design software for shell and tube heat exchanger based on MATLAB 7. 6. By varying the structures of heat exchanger, fully using of pressure drop between shell and tube gap can improve heat transfer coefficient and reduce heat exchange area. By analysis of the designed case, the results prove that the heat transfer coefficient increases by 21% and the heat exchange area reduces by 20% , thus the cost of heat-exchanger can be decreased greatly. [Ch,4 fig. 2 tab. 10 ref.

  15. Overview of the Shell and Tube Heat Exchangers about Heat Transfer Enhancement Technology%管壳式换热器强化传热技术概述

    Institute of Scientific and Technical Information of China (English)

    齐洪洋; 高磊; 张莹莹; 周辰琳

    2012-01-01

    The research progress of shell and tube heat exchanger were summarized. The development, structural improvement and heat transfer enhancement of the heat exchangers were introduced through three aspects,e. g. tube pass,shell pass and the whole tub bundle etc. Compared with the traditional seg-mental baffle heat exchanger, various types of heat exchangers' characteristics about heat transfer enhancement were epitomized. At last,the studying directions of heat exchangers were pointed out.%总结了近年来国内外新型管壳式换热器的研究进展,从管程、壳程、管束三方面介绍了管壳式换热器的发展历程、结构改进及强化传热机理,并与普通弓形折流板换热器进行对比,概括了各式换热器的强化传热特点.最后指出了换热器的研究方向.

  16. Flange Structure of Stainless Steel Shell and Tube Heat Exchanger%不锈钢管壳式换热器法兰结构

    Institute of Scientific and Technical Information of China (English)

    邓香中; 陈罡; 张光

    2016-01-01

    Welding neck lfange is widely used in shell and tube heat exchanger design, with the increase of stainless steel shell and tube heat exchanger in reifnery device, stainless steel structure of welding neck lfange has become the focus of the design choices. With a living example of stainless steel shell and tube type heat exchanger manufacturing, stainless steel lfange structure is analyzed. It is found that the design has broken the conventional ideas, and the integral stainless steel lfange is more used in engineering application. For welding lfange structure, single layer surfacing method is suggested to be implemented as soon as possible. Three kinds of stainless steel lfange structure are assessed, and the stainless steel lfange structure selection proposal is given.%长颈对焊法兰广泛应用于管壳式换热器的设计中,随着炼化装置不锈钢管壳式换热器应用的增多,长颈对焊法兰的不锈钢结构成为设计选择的焦点。以不锈钢管壳式换热器制造中的实例,分析不锈钢法兰结构形式,结果发现,设计已打破常规观念,日益倾向整体不锈钢法兰的工程应用;而对堆焊法兰结构则倾向于单层堆焊方式,设计应推广使用,促使制造尽快实施;并对3种不锈钢法兰结构进行评析,给出了不锈钢法兰结构选择的建议。

  17. Analyzing the effect on heat transfer due to nonuniform distribution of liquid flow among the tubes of a shell-and-tube heat exchanger

    Science.gov (United States)

    Zinkevich, A. I.; Sharifullin, V. N.; Sharifullin, A. V.

    2010-09-01

    A method is proposed using which nonuniform distribution of liquid flow among the tubes of a shell-and-tube apparatus can be taken into account by means of a statistical distribution function. A formula showing interrelation of this function with the indicator of heat transfer intensity in the apparatus tube space is given.

  18. Structural dynamics and fluid flow in shell-and-tube heat exchangers. Summary and overview of a DOE/ECUT-sponsored research program

    Science.gov (United States)

    Wambsganss, M. W.; Halle, H.; Mulcahy, T. M.

    1985-12-01

    Objective of the research program is to contribute to the design and development of energy-efficient, reliable, and cost-competitive industrial shell-and-tube heat exchangers. This report highlights the many technical contributions of the DOE/ECUT-sponsored program, reviews industry's use of the program results, and identifies research needs. Vibration excitation mechanisms, fluid/structure coupling, and flow distribution are briefly reviewed to provide background information. To date, the program has focused on the development of data bases of tube vibration and pressure drop information, derived from tests of a specially designed industrial-size heat exchanger. The development of an improved prediction method for fluid-elastic instability thresholds and the numerical simulation and measurement of flow distribution have also been addressed. Gas and two-phase flow testing is among the future research needs identified; such testing would require substantial modifications to the existing Heat Exchanger Test Facility. Industrial support, leading to a DOE/industry co-sponsored research pr ogram, is sought to allow for required modifications to the test facility, subsequent gas and two-phase flow testing, and expansion of the program to include further development of vibration and flow distribution prediction methods and related research.

  19. 管壳式换热器布管对换热效率的影响%Effect of tube distribution on the heat-exchanging efficiency of Shell-and-Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    甘树坤; 崔丽; 谢毛毛; 吕雪飞

    2012-01-01

    The heat-exchanging efficiency is usually improved by the split-range tube distribution in the design of Shell-and-Tube Heat Exchanger.The ratios between each tube range have great influence on the heat-exchanging efficiency of heat exchanger.The result that the heat-exchanging efficiency of non-uniform distributing tube is higher than that of uniform distributing tube is proved by theoretical formula.%在管壳式换热器设计中,通常通过分程来提高换热效率,但在分程布管时,各管程的布管比例,对换热器的换热效率有较大的影响,本文通过推导证明了非均匀布管比均匀布管换热效率高的结论.

  20. Experimental Evaluation of a Paraffin as Phase Change Material for Thermal Energy Storage in Laboratory Equipment and in a Shell-and-Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Jaume Gasia

    2016-04-01

    Full Text Available The thermal behavior of a commercial paraffin with a melting temperature of 58 °C is analyzed as a phase change material (PCM candidate for industrial waste heat recovery and domestic hot water applications. A full and complete characterization of this PCM is performed based on two different approaches: a laboratory characterization (mass range of milligrams and an analysis in a pilot plant (mass range of kilograms. In the laboratory characterization, its thermal and cycling stability, its health hazard as well as its phase change thermal range, enthalpy and specific heat are analyzed using a differential scanning calorimeter, thermogravimetric analysis, thermocycling and infrared spectroscopy. Laboratory analyses showed its suitability up to 80 °C and for 1200 cycles. In the pilot plant analysis, its thermal behavior was analyzed in a shell-and-tube heat exchanger under different heat transfer fluid mass flow rates in terms of temperature, power and energy rates. Results from the pilot plant analysis allowed understanding the different methods of heat transfer in real charging and discharging processes as well as the influence of the geometry of the tank on the energy transferred and required time for charging and discharging processes.

  1. 预测管壳式换热器温度分布的模型%Model of predicting temperature distribution in shell-and-tube heat exchanger

    Institute of Scientific and Technical Information of China (English)

    雷俊杰; 周帼彦; 朱冬生

    2011-01-01

    On the basis of the differential theory, a simplified but accurate model for predicting temperature distribution in single phase shell-and-tube exchanger was proposed. In line with the number of baffles Nb and tube passes n, an exchanger was divided into (Nb + 1) big units and then (Nb + 1)n small subunits, with tube side current flowing through the subunits in series and shell side current through the big elements in parallel. Two examples of BEU and AES heat exchangers were analyzed to demonstrate the application and accuracy of the present model in temperature distribution prediction, compared with the Cell model and HTRI method. The results show that the present model reproduces the temperature distribution given by the HTRI solution on the tube side flow with 0. 19% accuracy for the BEU heat exchanger and 0. 35% for the AES heat exchanger. While the max. Error of the Cell model is 1.74% and 6.44% respectively and the errors of the present model and Cell model on the shell side are -0.44% versus 1.69% for the AES heat exchanger. The present model applies to single phase shell-and-tube heat exchangers with bare tubes.%基于微分法,提出了一种简单但精确的单相管壳式换热器温度分布计算模型.根据折流板数Nb和管程数n,将换热器划分成(Nb+1)个大单元,(Nb+1)n个子单元,管程流体顺次流过子单元,壳程流体平行流过大单元.以HTRI方法为基准,分别采用本模型和Cell模型对U型管式和浮头式换热器温度分布情况进行计算,通过与HTRI的计算结果比较,验证了该计算模型的可行性和准确性.结果表明:相同操作条件下,该文模型和Cell模型计算BEU型换热器管程温度分布最大误差分别为0.19%和1.74%;计算AES型换热器管程最大误差分别为0.35%和6.44%,壳程最大误差分别为-0.44%和1.69%.模型适用于光管构成的单相管壳式换热器.

  2. 管壳式换热器换热管的传热强化%Heat Transfer Enhancement of Shell and Tube Heat Exchanger Heat tTransfer Tube

    Institute of Scientific and Technical Information of China (English)

    李若兰; 丁杰; 霍正齐

    2013-01-01

    This paper introduces the heat transfer and saving energy unit of the shell and tube heat exchanger -heat transfer enhancement technology of heat transfer tube and new approaches for the development of heat transfer tech -nology.Briefly introduce the structure , performance of the typical enhanced heat transfer tube and analyze the en-hanced heat transfer mechanism of heat transfer tube.%本文介绍管壳式换热器的传热节能元件-换热管的强化传热技术,指出传热技术发展新途径。简述典型强化换热管的构造、性能,分析换热管强化传热机理。

  3. 管壳式换热器管束流致振动实例分析%Examples Analysis of the Vibration Induced by Shell and Tube Heat Exchanger Tube Bundle Flow

    Institute of Scientific and Technical Information of China (English)

    矫明

    2014-01-01

    Elaborate the vibration mechanism induced by shell and tube heat exchanger tube bundle flow . Based on the Xist and Xvib modules of the HTRI software ,analyze and study the examples of vibration induced by shell and tube heat exchanger tube flow , and compare the advantages , disadvantages and adaptability between the HTRI‐Xist and HTRI‐Xvib analysis .%阐述管壳式换热器管束流致振动的机理,基于HTRI软件的Xist和Xvib模块,进行管壳式换热器管束流致振动实例的分析与研究,并比较了HTRI‐Xist与HTRI‐Xvib分析方法的优缺点及适应性。

  4. 管壳式换热器数值模拟的并行计算技术研究%Study on Parallel Computing Technology for Numerical Simulation of Shell-and-Tube Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    郭崇志; 肖乐

    2011-01-01

    利用并行计算原理,在FLUENT软件中对GAMBIT建模的管壳式换热器进行了数值模拟.通过对3种组合计算平台所消耗的机时进行比较,得到并行加速比和并行效率的规律,为复杂的管壳式换热器壳程设计的工程仿真和优化提供了一种新的处理方法.%Making use of parallel computing theory, the model for shell-and-tube heat exchangers was established with GAMBIT and simulated with FLUENT. The time of simulating three computing platforms were compared to get the trend of acceleration ratio and parallel efficiency so as to provide a new approach for design simulation and optimization of complicated shell-and-tube heat exchangers.

  5. 制冷装置用管壳式换热器清洁度管控研究%The Research of Management and Control the Cleanliness of Shell-and-tube Heat-exchanger Used in Refrigeration Equipment

    Institute of Scientific and Technical Information of China (English)

    周艳彬; 王少军; 杨久子

    2014-01-01

    This paper describes the importance of cleanliness to refrigeration equipment of central air-conditioning. Aiming at the shell-and-tube heat exchanger, it analyzes the pollution resource, and mainly discusses the control method and measurement of the cleanliness level from the perspectives of the design structure, the parts processing, and the shell-and-tube heat exchanger process.%本文讲述了清洁度对于中央空调制冷主机的重要性。针对管壳式换热器,分析了污染杂质来源,并从设计结构、零部件加工和管壳式换热器总成工艺三方面重点讨论其清洁度控制方法和措施。

  6. Research Development about Computer Aided Design of Shell and Tube Heat Exchanger%管壳式热交换器计算机辅助设计研究进展

    Institute of Scientific and Technical Information of China (English)

    王佳; 胡明辅; 钟浩文

    2013-01-01

    管壳式热交换器具有一些其他热交换器无法比拟的优点,在过程工业中处于主导地位.随着计算机技术发展,计算机辅助设计逐渐取代了以往繁杂的人工设计计算.综述了近年来管壳式热交换器计算机辅助设计的研究进展,从国内、国外两方面介绍了最新的计算机辅助设计软件,并简要分析了管壳式热交换器计算机辅助设计发展中存在的一些问题.%Shell and tube heat exchanger play the leading role in process industry, because they have some advantages that others can't exceed. With the development of the computer, the computer aided design gradually replaced the multifarious conventional design. The research and development about computer aided design of shell and tube heat exchanger recently were summarized, and the newest computer aided software in both local and foreign was introduced. Some problems in the development about computer aided design of shell and tube heat exchanger were briefly analyzed.

  7. 管壳式换热器壳程流体流动与传热数值模拟%Numerical Simulation Study of Shell-Side Fluid Flow and Heat Transfer in Shell-and-Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    付磊; 曾燚林; 唐克伦; 贾海洋

    2012-01-01

    A parametric model on the shell and tube heat exchanger was established using ANSYS parametric modeling method. The numerical simulation on the shell -side fluid flow and heat transfer of shell and tube heat exchanger was performed on ANSYS FLUENT 13.0 software, and the effects of the baffle plate spacing and entrance velocity to the heat transfer efficiency and the fluid induced vibration were discussed , and the structure optimization design of the heat exchanger are proposed based on the results.%利用ANSYS参数化建模方法建立了管壳式换热器的参数化模型,在ANSYS FLUENT 13.0模拟软件中对管壳式换热器的壳程流体的流动与传热进行了数值模拟计算,得到了不同折流板间距及入口流速的情况下换热器壳程流体温度场、速度场和压力场,分析了折流板间距及入口流速对换热效率和流体诱导振动的影响,对换热器结构优化设计提出了改进措施.

  8. FLOW AND HEAT TRANSFER CHARACTERISTICS IN SHELL SIDE OF SHELL-AND-TUBE HEAT EXCHANGERS WITH SEPARATED BAFFLES PARALLEL TO SEGMENTAL BAFFLES%平行流分隔板管壳式换热器壳侧流场与传热性能

    Institute of Scientific and Technical Information of China (English)

    王杨君; 邓先和; 陈颖; 李志武

    2004-01-01

    A shell-and-tube heat exchanger with separated baffles parallel to segmental baffles was proposed, and an investigation on velocity distribution, heat transfer and flow resistance characteristics in the shell side of the proposed heat exchanger and traditional single segmental baffled shell-and-tube heat exchanger was reported. After the experiment, the empirical relations of heat transfer and flow resistance were obtained. The heat transfer enhancement comprehensive evaluation factor η was in the range from 1.15 to 1.20 for Reynolds number (1.25×104-3.35×104). The resuhs indicated that flow field uniformization was enhanced in the shell side of shell-and-tube heat exchangers by two separated baffles parallel to segmental baffles and the performance of heat transfer was improved by controlling the dimension of vortices. The results could be used as reference in further research.

  9. Effect of baffle orientation on heat transfer performance of shell-and-tube heat exchangers%折流板切口方向对管壳式换热器传热性能影响

    Institute of Scientific and Technical Information of China (English)

    文宏刚; 周帼彦; 朱冬生; 覃新川

    2012-01-01

    为了研究单弓形折流板的切口方向对管壳式换热器传热与流动性能的影响,文中通过建立3个不同折流板切口方向的管壳式换热器简化实体模型,运用CFD软件Fluent对管壳式换热器壳程传热与流动状态进行了三维数值模拟.以水为壳程流体介质,在不断改变壳程进口流速,使得壳程进口雷诺数Re在10000到70000范围内变化时,得到了不同状态下的壳程流场与温度场.根据数值模拟结果,以总传热系数α,壳程总压降△p以及单位压降下的传热系数α/△P作为综合衡量标准,分析不同折流板切口方向时的管壳式换热器壳程流场与温度场.数值模拟分析结果表明:折流板为垂直切口方向时,管壳式换热器总传热系数最大,压降最小,综合性能最好,另外2种折流板切口方向的管壳式换热器综合性能差不多.%In order to study the effect of baffle orientation on the heat transfer and pressure drop in a shell-and-tube heat exchanger, three simplified physical models of shell-and-tube heat exchanger with different baffle orientation were built for three dimensional numerical simulation. The shellside turbulent flow and heat transfer characteristics of shell-and-tube heat exchanger were studied by using computational fluid dynamics (CFD) software Fluent. With water as fluid medium, the pressure fields and temperature fields of shellside at different shellside flow rates were gained by constantly changing the shellside inlet flow rates to keep Reynolds numbers ranging from 10 000 to 7 000. According to the numerical simulation results, the performance of three shell and tube heat exchanger models was compared and assessed by using heat transfer coefficient a, pressure drop △p, and the comprehensive performance factor a/△p. The results show that when the baffle orientation is in vertical, the total heat transfer coefficient of shell-and-tube heat exchanger is the maximum, pressure drop is the

  10. Evaluation of Nutritional and Physical Properties of Watermelon Juice during the Thermal Processing by Using Alumina Nano-fluid in a Shell and Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Farinaz Saremnejad Namini

    2015-09-01

    Full Text Available Background and Objectives: Thermal processing is an effective method in preventing microbial spoilage but high heat transfer in a long time process that leads to quality loss and increased energy consumption. Also it is important to consider sensitive nature of food products during the thermal processing. Due to the nano-fluids' unique thermo–physical properties compared with the conventional fluids (steam and hot water, their use in various industries to enhance the efficiency of equipment and energy optimization has increased. Materials and Methods: The effects of alumina–water nano-fluids (0, 2, and 4% concentrations on some nutritional properties (lycopene and vitamin C content, and some physical properties (color, pH and TSS of watermelon juice treated by high temperature–short time (75, 80, and 85°C for 15, 30, and 45 seconds in a shell and tube heat exchanger were evaluated. Results: In compared with water, process time reduced by 24.88% and 51.63% for 2% and 4% nano-fluids, respectively. It had a significant effect on improving the properties of watermelon juice (P<0.05. Under the treatment conditions (75°C and 15s, with 0, 2, and 4% nano-fluids, 81.15, 84.81, and 91.28% of lycopene and 61.11, 63.70 and 67.04% of vitamin C were maintained, respectively. &DeltaE* values for the fruit juices processed with 0, 2 and 4% nano-fluids were 3.26, 2.21 and 1.14, respectively. Also pH and TSS changed in the range of 5.58–5.82 and 9.00–9.40%, respectively. Conclusions: The results showed that qualitative and nutritional properties of watermelon juices processed with nano-fluids in terms of lycopene and vitamin C retention, and color were, respectively, 9.89, 6.18 and 50.38% better than the samples processed with water.

  11. 管壳式换热器流体流动与耦合传热的数值模拟%Numerical simulation of shell and tube heat exchanger fluid flow and coupled heat transfer

    Institute of Scientific and Technical Information of China (English)

    付磊; 唐克伦; 文华斌; 王维慧; 付伶

    2012-01-01

    结合化工行业中使用的某型号管壳式换热器的结构图和工艺参数,对换热器的结构进行了合理的简化,利用ANSYS参数化建模方法建立了管壳式换热器的参数化模型。在ANSYS FLUENT14.0数值模拟软件中对换热器的流体流动以及耦合传热进行了数值模拟,得到管程和壳程流体的流速分布、压降情况、温度场变化的细节信息。该工作对于设计传热效率高、流体阻力小的换热器进行了有益探索。%This paper presented a numerical simulation of shell and tube heat exchanger fluid flow and coupled heat transfer.The structure of the heat exchanger currently being used in chemical industry was simplified.A numerical model of a shell and tube heat exchanger was established using ANSYS FLUENT14.0,under which the model was tested.Fluid velocity distribution,pressure drop conditions and temperature changes inside the heat exchanger tube were obtained and analyzed.This research could be beneficial to the design of heat exchanger with high heat transfer efficiencies and low fluid resistance.

  12. 基于FLUENT的管壳式换热器壳程流场数值模拟研究%Numerical Simulation Study of Shell-Side Fluid in Shell-and-Tube Heat Exchanger Through FLUENT

    Institute of Scientific and Technical Information of China (English)

    付磊; 付丽娅; 唐克伦; 文华斌; 李良

    2012-01-01

    利用ANSYS参数化建模方法建立了管壳式换热器的参数化模型,在ANSYSFLUENT中对管壳式换热器壳程流体的流动与传热进行了数值模拟计算,得到换热器壳程流体温度场、速度场和压力场;分析了折流板间距及弦高对换热效率和壳程流体压降的影响,对于设计传热效率高、流体阻力小的换热器进行了有益探索。%A parametric model on the shell and tube heat exchanger is established by using ANSYS parametric modeling method. The numerical simulation on the shell-side fluid flow and heat transfer of shell and tube heat exchanger is performed on ANSYS FLUENT, and Shell-side fluid temperature field, velocity field and pressure field are acquired;and the effects of the baffle plate spacing and string height of heat exchanger to the heat transfer efficiency and shell side fluid pressure drop is analyzed. It is a beneficial exploration to the design to high heat transfer efficiency and low fluid resistance of the heat exchanger.

  13. Numerical Simulation and Analysis of Shell-Side Flow Field in Shell-and-Tube Heat Exchanger Based on FLUENT%基于FLUENT的管壳换热器壳程流场数值模拟与分析

    Institute of Scientific and Technical Information of China (English)

    刘磊; 宋天民; 管建军

    2012-01-01

    通过简化管壳式换热器模型,采用非结构网格划分,选用κ-ε湍流模型,应用CFD软件FLUENT对壳程流体流动和传热过程进行了数值模拟,得到了不同折流板间距情况下壳程流体温度场、压力场以及速度场的分布情况.分析了折流板间距对壳程流体流场分布、换热器传热速率以及压力损失的影响,并得出了进口流速与传热量和压力损失之间的关系.模拟结果与理论研究结果相符合,对管壳式换热器的设计和改进有一定的参考价值.%By simplified the model of shell-and-tube heat exchangers, adopted the unstructured mesh, chose the k-S turbulence model to gain the static temperature field, velocity field and static pressure field distribution of shell by taking numerical simulation of the shell side turbulent flow and heat transfer process with the CFD software FLUENT at different baffle spacing. Analyzed the effect of baffle spacing on the distribution of shell fluid flow, heat transfer rate and pressure drop, also acquired the relationship between inlet velocity and heat transfer rate, pressure drop. The simulation results consistent with the theoretical results of shell-and-tube heat exchangers, which can be a reference for the design and improvement of shell-and-tube heat exchangers.

  14. Development of Structure Optimization of Tube Bundle in the Shell and Tube Heat Exchanger%管壳式换热器管束结构优化发展概述

    Institute of Scientific and Technical Information of China (English)

    郝国永; 张莹莹; 高磊; 于宵航; 吴亮

    2014-01-01

    总结了近年来国内外新型管壳式换热器的管束结构发展进展,从管程、壳程两个方面介绍了管壳式换热器管束结构改进及强化传热机理,并且介绍了几种新型结构在实际生产中的成功应用及其强化传热特点。最后为换热器管束结构发展提出建设性意见。%The development progress in new tube bundle structure of shell and tube heat exchanger in recent years at home and abroad was summed up. Structure improvement and strengthening heat transfer mechanism of the shell and tube heat exchanger were introduced from two aspects of tube and shell. And successful application of several new structures in the actual production and its enhanced heat transfer characteristics were introduced. Finally, constructive suggestions about tube bundle structure development of the heat exchanger were put forward.

  15. Optimization design of shell-and-tube heat exchangers based on genetic algorithm%应用遗传算法优化设计壳管式换热器

    Institute of Scientific and Technical Information of China (English)

    李夔宁; 张继广; 李进; 郭军峰

    2011-01-01

    针对壳管式换热器传统设计方法繁杂且结果又不能满足最佳经济费用的缺点,引入遗传算法对壳管式换热器进行设计。建立了相应的数学模型并以设备总费用为目标函数,对换热器进行优化设计。利用遗传算法智能及多点搜索等特性,不断地迭代优化变量,在优化变量值和约束条件范围内,得到最小目标函数的设计结果。采用了2个实际算例进行测试,结果显示在满足换热性能的前提下,优化后总费用都有降低,降幅分别为18.2%,7.98%。%Genetic algorithm(GA) is used for the optimal design of shell-and-tube heat exchangers due to the fact that traditional designs for shell-and-tube heat exchangers are complicated and uneconomical.To optimize the design of heat exchangers,mathematical models are established and the total costs are used as the objective function.Taking advantage of GA's intelligent and multi-searching characteristics,researchers continuously iterate optimization variables and then obtain the minimum objective function of the design results within the optimal variable values and constraints.Two practical heat exchangers are used to test the research results.The Optimization results show that the optimized total costs have decreased by 18.2% and 7.98% respectively,which can also satisfy the heat transfer performance.Moreover,the results show that the design based on GA for shell-and-tube heat exchangers can significantly improve the economic efficiency of heat exchangers and thus can be applied to engineering practice.

  16. Effect of tube pitch on heat transfer in shell-and-tube heat exchangers—new simulation software

    Science.gov (United States)

    Karno, A.; Ajib, S.

    2006-02-01

    A new program for simulation and optimization of the shell-and-tube heat exchangers is prepared to obtain useful results by employment of the computing technology fast and accurately. As an application of this program, the effects of transverse and longitudinal tube pitch in the in-line and staggered tube arrangements on the Nusselt numbers, heat transfer coefficients and thermal performance of the heat exchangers were investigated. The obtained values of the tube pitch were compared with literature values.

  17. 新型管壳式换热器三维流场分析%Analysis of Fluid Flow Field in Shell Sides of Shell-and-Tube Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    王珂; 王永庆; 董晓琳; 古新

    2011-01-01

    Analysis of fluid flow characteristics is carried out in shell sides of shell-and-tube heat exchangers with segmental baffle, rod baffle and H-shape baffle, by using periodic numerical models. The main distinction of the three typical flow types corresponding to these heat exchangers lies in different fluid transversal velocity component. The ratio magnitude of fluid transversal velocity component to longitudinal velocity component remains a constant for each flow type in different fluxes. The difference of pressure drop and heat transfer coefficient between shell-and-tube heat exchangers with varied baffles is caused mainly by different ratio magnitude of fluid transversal velocity component to longitudinal velocity component.%本文应用周期性简化模型,对弓型、杆式以及H型壳程支撑结构的管壳式换热器壳程内的流动特性进行了分析。对于其对应的三种典型流态,反映在壳程内流体流动方面的主要差别是壳程内横向流速度分量的不同,且三种流态各自在不同流量下的横向流速度分量与纵向流速度分量之比几乎均为一定值。具有不同管束支撑结构的管壳式换热器壳程内流体阻力降与传热系数不同,主要原因在于其壳程内流体的横向流速度分量的大小存在差别。

  18. 管壳式换热器的振动特性分析及模态试验%Vibration characteristics analysis and modal experiment of shell and tube heat exchanger

    Institute of Scientific and Technical Information of China (English)

    童鲁海

    2009-01-01

    Aiming at the entrance and exit of one type of shell and tube heat exchanger are easily damaged. With the combination of finite element model analysis and experimental model analysis, the dynamic characteristics of the heat exchanger were analyzed. The results indicate that its natural frequency is above 180 Hz which avoids the excitation frequency produced by flow-induced vi-bration, but the stiffness of tube entrance and exit and the connection position strength between shell and bolt need to be strength-en. The finite element modal analysis method is verified by experiments which could provide references for rapid evaluation of dy-namic characteristics on other types of shell and tube heat exchanger and reliability optimization design.%针对桌一型号管壳式换热器管程入口和出口处容易损坏的问题,采用有限元模态分析和试验模态分析相结合的方法,对其动态特性进行了分析.研究结果表明其固有频率在180 Hz以上,避开了流体诱导振动产生的激振频率,但需加强其管程入口和出口处的刚度和壳体螺栓连接部位的连接强度.有限元模态分析方法可为其他类型管壳式换热器的动态特性快速评价和可靠性优化设计提供参考.

  19. The Numerical Simulation Analysis on Heat Transfer Efficiency Influence Factors of Shell and Tube Heat Exchanger%管壳式换热器传热效率影响因素及数值模拟分析∗

    Institute of Scientific and Technical Information of China (English)

    王庆锋; 庞鑫; 赵双

    2015-01-01

    多数管壳式换热器基于传统的经验设计方法,换热器质量大且能耗高。鉴于此,采用Fluent仿真模拟的方法,研究了换热管类型、折流板间距、折流板切率变化与换热器对流传热系数的关系,并用HTFS工程软件进行了模型验证。研究结果表明,采用特型管(如波节管和波纹管等)代替光管,可以增强管内流体扰动,提高湍流程度,增大管程对流传热系数,但同时也增大了压降;折流板间距越大,壳程对流传热系数越小,压降也越小,当折流板间距为330 mm时,换热器最高效,此时换热器在较小的压降下可以获得较大的对流传热系数;折流板切率越大,压降越小,当管束错流流速与折流窗口流速相等时,壳程对流传热系数最大,折流板切率35%为最优值,换热器效率最高。最后提出了管壳式换热器优化设计方法,将优化设计的换热器用于某化肥厂氮氢气压缩机级间冷却,同等热负荷条件下换热面积减小了21�37%。研究结果为换热器的结构参数优化提供了依据。%Most of shell and tube heat exchanger design based on traditional experiences have the issues of high weight and high energy consumption�The effects of heat transfer tube types, baffle spacing, and baffle plate cut rate on the heat exchanger convective heat transfer coefficient have been studied by suing fluent simulation method�The model is validated by HTFS engineering software�The results showed that the alternative special⁃shaped tube for the smooth tube, like the corrugated tube and bellows, could enhance fluid disturbances and the turbu⁃lence level, increase the tube convective heat transfer coefficient, but also increases the pressure drop�Increase the baffle plate spacing will decrease the shell side convective heat transfer coefficient and the pressure drop�The heat exchanger is the most efficient when the baffle plate

  20. Experimental investigation of heat transfer performance coefficient in tube bundle of shell and tube heat exchanger in two-phase flow

    Science.gov (United States)

    Karaś, Marcin; Zając, Daniel; Ulbrich, Roman

    2014-03-01

    This paper presents the results of studies in two phase gasliquid flow around tube bundle in the model of shell tube heat exchanger. Experimental investigations of heat transfer coefficient on the tubes surface were performed with the aid of electrochemical technique. Chilton-Colburn analogy between heat and mass transfer was used. Twelve nickel cathodes were mounted on the outside surface of one of the tubes. Measurement of limiting currents in the cathodic reduction of ferricyanide ions on nickel electrodes in aqueous solution of equimolar quantities of K3Fe(CN)6 and K4Fe(CN)6 in the presence of NaOH basic solution were applied to determine the mass transfer coefficient. Controlled diffusion from ions at the electrode was observed and limiting current plateau was measured. Measurements were performed with data acquisition equipment controlled by software created for this experiment. Mass transfer coefficient was calculated on the basis of the limiting current measurements. Results of mass transfer experiments (mass transfer coefficient) were recalculated to heat transfer coefficient. During the experiments, simultaneously conducted was the the investigation of two-phase flow structures around tubes with the use of digital particle image velocimetry. Average velocity fields around tubes were created with the use of a number of flow images and compared with the results of heat transfer coefficient calculations.

  1. Experimental investigation of heat transfer performance coefficient in tube bundle of shell and tube heat exchanger in two-phase flow

    Directory of Open Access Journals (Sweden)

    Karaś Marcin

    2014-03-01

    Full Text Available This paper presents the results of studies in two phase gasliquid flow around tube bundle in the model of shell tube heat exchanger. Experimental investigations of heat transfer coefficient on the tubes surface were performed with the aid of electrochemical technique. Chilton-Colburn analogy between heat and mass transfer was used. Twelve nickel cathodes were mounted on the outside surface of one of the tubes. Measurement of limiting currents in the cathodic reduction of ferricyanide ions on nickel electrodes in aqueous solution of equimolar quantities of K3Fe(CN6 and K4Fe(CN6 in the presence of NaOH basic solution were applied to determine the mass transfer coefficient. Controlled diffusion from ions at the electrode was observed and limiting current plateau was measured. Measurements were performed with data acquisition equipment controlled by software created for this experiment. Mass transfer coefficient was calculated on the basis of the limiting current measurements. Results of mass transfer experiments (mass transfer coefficient were recalculated to heat transfer coefficient. During the experiments, simultaneously conducted was the the investigation of two-phase flow structures around tubes with the use of digital particle image velocimetry. Average velocity fields around tubes were created with the use of a number of flow images and compared with the results of heat transfer coefficient calculations.

  2. 一种带状支撑的纵流壳程换热器热力特性分析%Analysis of Thermodynamic Characteristics in Shell Side of a Shell-and-tube Heat Exchanger with Ribbon Support

    Institute of Scientific and Technical Information of China (English)

    王永庆; 靳遵龙; 郭晓迪; 雷佩玉; 郭月明

    2013-01-01

    以纵流壳程换热器作为研究对象,对一种带状支撑纵流壳程换热器的壳程流体流动与传热特性进行了数值研究与分析.基于纵流壳程换热器的特性,建立了带状支撑结构的计算模型,对其流体流动与传热进行了数值计算,得到了壳程流场和温度分布等细观信息.对带状支撑换热器在不同几何参数及工况情况下的热力性能进行了综合分析,并将其特性与折流杆式支撑壳程特性进行了对比分析.研究表明,在相同的流动条件下,带状支撑结构壳程内,流体具有较强的湍动度,增大了的换热效果.%The shell-and-tube heat exchanger with longitudinal fluid flow in shell side was selected as the research object.The characteristics of fluid flow and heat transfer in shell side of shell-and-tube heat exchanger with a ribbon support structure were studied numerically.Based on the characteristics of fluid flow and heattransfer in shell side of heat exchanger,the periodic unit duct model was presented and adopted in the numerical calculations for heat exchanger.The detailed information of the fluid flow and temperature field were obtained.The thermodynamic characteristics in shell side of the ribbon support structures with different parameters were analyzed comprehensively.In addition,the characteristics were compared with that of rod baffle heat exchanger,another heat exchanger with longitudinal fluid flow in shell side.It is concluded that in the same condition,in shell side with a ribbon support structure,fluid is of bigger turbulent intensity,which enhances heat transfer.

  3. Perancangan Heat Exchanger Type Shell And Tube Untuk After Cooler Kompressor Dengan Kapasitas 8000 m3/hr Pada Tekanan 26,5 Bar

    OpenAIRE

    Siregar, Franky S.

    2011-01-01

    Dalam kehidupan sehari-hari banyak terlihat fenomena perpindahan panas dari material atau fluida yang mempunyai temperatur lebih tinggi ke material atau fluida yang mempunyai temperatur lebih rendah. Dalam dunia industri fenomena perpindahan panas tersebut dimanfaatkan untuk keperluan proses dengan menggunakan suatu alat yang biasa disebut sebagai penukar panas atau heat exchanger. Heat exchanger merupakan alat yang digunakan sebagai media untuk memindahkan panas dari fluida yang bertemperatu...

  4. Research on Shell-and-Tube Heat Exchanger Optimize Design%管壳式换热器优化设计研究

    Institute of Scientific and Technical Information of China (English)

    吴健

    2015-01-01

    设计一台换热性能优良的管壳式换热器,涉及内容较多,包括初始条件确立、换热管尺寸、壳体类型等信息确定等。本文通过实际应用研究,总结出了换热管尺寸对换热器大小和性能的影响的规律,在借鉴前人研究成果和企业实际应用的基础上,对管壳式换热器的优化设计进行了总结,并提出了一些建议,为换热器设计提供参考。%A better performance of the shell-tube heat exchanger was designed, involving main contents of initial conditions set, heat tube selection, etc. . Through the research of practical application, effect of heat exchange tube size and the size of heat exchanger performance rule was summarized. Based on the results of previous studies, the shell-tube heat exchanger design contents were summarized, and some suggestions were putforward, which can provide reference for the design of heat exchanger.

  5. Shell-side heat transfer performances of shell-and-tube heat exchanger with multi-parallel-channel%并流多通道管壳式换热器壳程传热性能

    Institute of Scientific and Technical Information of China (English)

    曾文良; 张正国

    2012-01-01

    对并流多通道进出口(MPC)轴流管壳式换热器壳程传热性能进行数值模拟,分别研究了管排数N,Re,不同开孔率的挡板对壳程进口段的局部传热系数分布、局部平均Nu的分布、换热器的平均Nu等特性的影响.结果表明:在无挡板条件下,随着N的减小,壳程传热系数分布不均现象得到有效的遏制,N=7时基本上无传热死区.挡板的存在,不但使得进口段的局部传热系数分布更加均匀,而且能够提高换热器的整体传热Nu.不同参数的挡板之间,挡板1的作用最为明显,可以使得Nu提高10%-12%.%Shell-side heat transfer performances of inlet and outlet of longitudinal flow shell-and-tube heat exchanger with multi-parallel-channel (MPC) were numerically simulated. The influences of baffle on the local heat transfer coefficient distribution of inlet region, local-mean Nu distributions, and mean Nu of heat exchanger were investigated with pipe-line-number, N, Re and different punching ratio, respectively. The results reveal that with the decreasing of N, the non-uniformity of local heat transfer coefficient is effectively improved and there is not any heat transfer skip area when N =7. It also shows that fluid-distribution-baffles ( FDBs) can not only effectively improve the local heat transfer coefficient distribution of inlet region but also enhance the global Nu of heat exchanger. The comparison of different FDBs shows that FDB of No. 1 has the best performance and can enhance Nu by 10%-12%.

  6. 管壳式换热器流动与传热的三维数值模拟%A Three-Dimension Numerical Study on the Heat Transfer and Fluid Flow of a Shell-and-tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    俞接成; 诸葛一然

    2012-01-01

    应用计算流体力学软件FLUENT对一小型管壳式换热器的流动与传热问题进行了三维数值模拟.换热器壳体直径为130 mm,12根φ20 mm×1 500 mm的换热管正方形排列,折流板为30%缺口的弓形折流板,模拟了3种不同折流板间距的情况.模拟过程采用雷诺应力湍流模型,压力速度耦合选用SIMPLEC格式,压力方程的离散选用Standard格式,其他方程的离散均选用QUICK格式.数值模拟结果表明:减小折流板间距对总体传热系数的增加不太明显,但却显著增加了壳程的流动阻力.最后应用Bell法对3种不同折流板间距的数值模拟结果进行了校核,他们之间的最大误差为6.57%,表明数值模拟结果准确可靠.%A three-dimension numerical study on the heat transfer and fluid flow of a small shell-and-tube heat exchanger is performed by using the commercial CFD software package FLUENT. The shell diameter of the heat exchanger is 130 mm, which has twelve ψp20 × 1500 mm tubes arranged by square mode, and a segmental baffle with 30% cut, simulating three different baffle spacing. The Reynolds stress model for turbulent flow, SIMPLEC scheme for pressure-velocity coupling, standard scheme for pressure equation discretization and QUICK scheme for other equation discretization are selected in this numerical study. The numerical results show that the overall heat transfer coefficient increases relatively small by decreasing the baffle spacing, but the shell drag increases significantly. Finally, the numerical result of the three different baffle spacing is checked by Bell method, and their maximal deviation is 6. 57%, which confirmed the numerical result. The numerical method can be utilized further to optimize the internal structure and enhance the overall performance of the heat exchanger.

  7. Effect of the sequence of tube rolling in a tube bundle of a shell and tube heat exchanger on the stress-deformed state of the tube sheet

    Science.gov (United States)

    Tselishchev, M. F.; Plotnikov, P. N.; Brodov, Yu. M.

    2015-11-01

    Rolling the tube sheet of a heat exchanger with U-shaped tubes, as exemplified by the vapor cooler GP-24, was simulated. The simulation was performed using the finite element method with account of elas- tic-plastic properties of the tube and tube sheet materials. The simulation consisted of two stages; at the first stage, maximum and residual contact stress in the conjunction of a separate tube and the tube sheet was determined using the "equivalent sleeve" model; at the second stage, the obtained contact stress was applied to the hole surface in the tube sheet. Thus, different tube rolling sequences were simulated: from the center to the periphery of the tube sheet and from the periphery to the center along a spiral line. The studies showed that the tube rolling sequence noticeably influences the value of the tube sheet residual deflection for the same rolling parameters of separate tubes. Residual deflection of the tube sheet in different planes was determined. It was established that the smallest residual deflection corresponds to the tube rolling sequence from the periphery to the center of the tube sheet. The following dependences were obtained for different rolling sequences: maximum deformation of the tube sheet as a function of the number of rolled tubes, residual deformation of the tube sheet along its surface, and residual deflection of the tube sheet as a function of the rotation angle at the periphery. The preferred sequence of tube rolling for minimizing the tube sheet deformation is indicated.

  8. 管壳式换热器课程设计应重视流速和压力降的选取%The Selection of Fluid Velocity and Pressure Drop Should be Payed Attention to the Courses Design of Shell and Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    吕江平; 李薇; 王晓萍; 伍家卫

    2011-01-01

    Influence of the flow speed and pressure drop was not frequently attached during the courses design of Shell-and tube heat exchanger in《The Principle of Chemical Engineering》.By analyzing,the paper pointed out that it was unreasonable.At the same time the paper proposed reasonable step of the shell and tube heat exchanger design and the recommendations on《The Principle of Chemical Engineering》course design.%《化工原理》管壳式换热器课程设计往往不重视流体流速和压力降对于换热器的影响,文章通过分析指出其不合理之处,提出合理的管壳式换热器设计步骤,同时对《化工原理》课程设计提出建议。

  9. Computer-Aided Thermohydraulic Design of TEMA Type E Shell and Tube Heat Exchangers for Use in Low Pressure, Liquid-to-Liquid, Single Phase Applications.

    Science.gov (United States)

    1985-04-01

    subroutine contains data on friction factors correlated by Sieder and Tate for fluids which are being heated or cooled in tubes. The subroutine uses a linear...inter- -". polation algorithm to calculate the friction factor depending on the Reynolds Number of the tube-side fluid. The Sieder and Tate correlated

  10. Evaporation of alternative refrigerants to R 22 in technical shell and tube heat exchangers; Verdampfung von Ersatzkaeltemitteln fuer R 22 in technischen Rohrbuendel-Waermeaustauschern

    Energy Technology Data Exchange (ETDEWEB)

    Bonekamp, S. [Henkel KGaA, Duesseldorf (Germany)

    2000-05-01

    The refrigerant mixtures R 404A, R 407C, R 410A and R 507 and the pure fluids R 134a, ammonia, propane and propene are mainly recommended for substituting R 22. This report shows the results of heat transfer calculations for these refrigerants over a wide application range for flooded and for direct expansion evaporation. To determine the best substitute for R 22 the heat transfer areas are compared and a ranking for both types of evaporators is presented. (orig.) [German] Als Ersatz fuer R 22 werden hauptsaechlich die Kaeltemittelgemische R 404A, R 407C, R 410A und R 507 sowie die reinen Stoffe R 134a, Ammoniak, Propan und Propen diskutiert. Diese Arbeit stellt Berechnungsergebnisse fuer die verschiedenen Ersatzkaeltemittel in einem grossen technischen Anwendungsbereich sowohl fuer ueberflutete als auch fuer Einspritz-Verdampfer vor. Der Vergleich der ermittelten Waermeaustauschflaechen liefert fuer beide Verdampfungsarten eine Reihenfolge fuer die Verwendbarkeit als Austauschstoff fuer R 22. (orig.)

  11. 管壳式换热器壳侧气液两相流动和传热的数值模拟研究%Study on Numerical Simulation of Gas-liquid Two-phase Flow and Heat Transfer of Shell Side in a Shell and Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    吕金丽; 戈锐; 李想; 张玉宝

    2012-01-01

    采用数值模拟方法,使用FLUENT对管壳式换热器壳侧的两相流动及相变传热进行了模拟计算.根据壳侧流体流动特点,选定合适的湍流模型、两相流模型为混合物模型,并根据汽水转化公式编写了自定义函数UDF来描述相变过程质和量的传递.对管壳式换热器壳侧的流体介质换热发生相变并产生气液两相流动进行了三维的数值模拟研究.得到了管壳式换热器壳程的速度场、温度场、压力场及气液各相的分布情况,对壳侧气液两相流动及相变换热进行了分析.对具有相变情况下的管壳式换热器的结构设计起到参考指导作用.%Numerical simulation methods are adopted in this paper. With the FLUENT software,the paper stimulates the two-phase flow and phase change and heat transfer. A turbulence model and a two-phase flow model are selected in this paper. Based on the characteristics of shell-side in the shell and tube heat exchangers, the paper writes User-defined Function (UDF) to describe the phase transition of quality and quantity through the use of the conversion formula. Flow media of shell and tube heat exchanger shell-side heat transfer occurring phase change and gas-liquid two-phase flow are studied by 3D numerical-simulation, obtaining velocity field, temperature field, pressure field and gas-liquid distribution of shell and tube heat exchanger shell side. The two-phase flow and phase change and heat transfer of shell-side in the shell and tube heat exchangers are analyzed. These will be provided some valuable references for the improvement of tube condenser structure design.

  12. Fluid Flow Field Distribution Comparison of Shell-and-Tube Heat Exchanger with Multi-Parallel-Channel%并流多通道管壳式换热器壳程流场分布比较

    Institute of Scientific and Technical Information of China (English)

    曾文良; 邓先和

    2013-01-01

      优化壳程流场分布和减少压降对并流多通道进出口结构(MPC)轴流管壳式换热器具有非常重要的作用。分别采用商用CFD软件FLUENT 6.3和皮托管测速方法对MPC换热器壳程流场分布与阻力性能进行数值模拟与实验研究,分别研究了管排数N、Re、不同开孔率的挡板对壳程流场分布、阻力性能的变化规律。结果表明:(1)无挡板时,随着N的减小,壳程流场分布不均现象得到有效的遏制,压降大幅降低,最大降幅达到70%以上;(2)挡板能够有效促进流场的二次分布,但亦使得阻力增大较为显著;(3)比较不同挡板,挡板1的效果最优;(4)换热器压降主要在进出口段产生。%  In order to solve the problems of the longitudinal flow shell-and-tube heat exchanger such as fluid flow maldistribution, high pressure drop and the overall performance deterioration, a novel structure of multi-parallel-channel inlet/outlet (MPC) was proposed. The numerical and experimental investigation on shell-side fluid flow distribution and resistance performances of the MPC heat exchanger were carried out by employing commercial CFD software of FLUENT 6.3 and Pitot tube velocimetry, respectively. Under the conditions of without FDBs (Fluid Destribute Baffles) and with FDBs of different punching ratioes, both shell-side fluid flow distribution and resistance performances were investigated under different Reynolds numbers (Re) and numbers of tube row (N) respectively. Investigation results show as follows: (1) Under the condition of without FDBs, with the decrease of N, the maldistribution of shell-side is effectively improved and the resistance performances can be reduced sharply, even more than 70%of total pressure drop can be reduced at same Re when N=11 decreases to N=7; (2) FDBs could effectively improve the shell-side fluid maldistribution, but the pressure drop will increase at the same time. (3) Comparison of different

  13. Study on the Influence of Baffle-tube Clearance on the Fluid Flow and Heat Transfer of Shell and Tube Heat Exchanger%管板间隙对管壳式换热器流动与传热的影响研究

    Institute of Scientific and Technical Information of China (English)

    耿伟轩; 张红; 陶汉中; 冯志伟

    2012-01-01

    In shell and tube heat exchanger,leakage flow caused by baffle -tube clearance is disadvantageous to the heat transfer of heat exchanger. By using a new method of grid generation, a three - dimensional numerical model is established and meshed,and the numerical simulations are carried out by using CFD code Fluent software to study the characteristics of fluid flow and heat transfer in shell side and tube pass under different conditions. The standard k梕 turbulent model and SIMPLEC method were used in calculations, and the pressure equation is of standard format. The simulated results are imported to the e-valuation indicator of heat exchanger to analyze, in an all - round way, the influence of baffle - tube clearance on the fluid flow and heat transfer of shell and tube heat exchanger.%管壳式换热器中,由管板间隙引起的漏流不利于换热器的传热.通过一种新型网格生成方法,对所建立的三维实体模型进行网格划分,并利用CFD软件Fluent进行数值模拟,研究不同情况下壳程与管程的流动与传热特性.计算中采用标准k-ε模型,SIMPLE算法,压力方程为标准格式.将模拟结果引入换热器评价指标,全面分析管板间隙对管壳式换热器流动与传热的影响.

  14. Numerical analysis of small-scale shell and tube heat exchanger flow field%小尺度管壳式换热器流场的数值分析

    Institute of Scientific and Technical Information of China (English)

    洪文鹏; 辛凯; 张全厚

    2012-01-01

    针对小尺度管壳式换热器的管间距选取问题,建立三维模型,基于Simple算法,采用SST k-ω湍流模型,结合有限体积法对控制方程进行离散,在管径d不变的情况下,分别针对管间距a=1.2d,a=1.4d和a=2.0d 3种不同的管间距工况对壳侧流场的分布及阻力变化进行了研究.由于管路附近的速度梯度较大,为了提高计算的精度,进行局部的网格细化,最终对比了不同模型的流场模拟效果.结果表明:阻力和湍流强度随着管间距的增大而减小,应按照压降的减小比例小于平均湍流强度的减小比例为原则来选取a的值.对于这种小尺度的流场模拟,采取实验的方法将受到极大的限制,通过大型商用流体仿真软件来模拟计算,为工程实际设计提供参考的依据.%For small-scale shell and tube heat exchanger tube spacing selection problems, by establishing three-dimensional model and based on the Simple algorithm, using the SST k-w turbulence model, combined with the finite volume discretization of equations and in the case of the same diameter, the shell side flow distribution and resistance changes were studied with three different tube spacing conditions respectively as a = 1. 2d, a = 1. 4d and a = 2. 0d. Because the larger velocity gradient near the pipeline, and in order to improve the accuracy of the calculation,the local grid refinement and the final comparison for the flow field simulation of different models were made. The results show that the resistance and turbulence intensity decrease with the increase of tube spacing, and the proportion should be reduced based on the principle that the ratio of pressure drop is less than the average ratio of turbulence intensity decrease to select a value. For this small-scale simulation of the flow field, the experimental approach is severely limited by large commercial flow simulation software simulation, which provides a reference basis of the actual design of the project.

  15. Shell-side fluid flow field in shell-and-tube heat exchanger with multi-parallel-channel%并流多通道管壳式换热器壳程流场分布

    Institute of Scientific and Technical Information of China (English)

    曾文良; 邓先和

    2011-01-01

    The decrease in length-diameter ratio may lead to some technical problems in shell-and-tube heat exchangers, such as fluid flow maldistribution, sharp increase of pressure drop, and performance deterioration. In order to solve above problems, two techniques are proposed in this study, application of a novel structure of multi-parallel-channel inlet/outlet (MPC) and installation of fluid flow distributors (FDBs) in the region of inlet/outlet in shell-side. The shell-side fluid flow is simplified according to its structural characteristics and the unit duct model is established. By employing commercial CFD software of FLUENT 6. 3, the numerical investigation on shell-side fluid flow was carried out. The numerical model and method were confirmed by experiment. Without FDBs and with FDBs of different punching ratios, both shell-side velocity distribution and resistance were investigated with different values of Reynolds number and number of tube rows (N). Without FDBs, as N decreases, the distribution of shell-side is effectively improved and the resistance is reduced sharply, with more than 70% of total pressure drop reduced when N decreases from 11 to 7 at the same Re. FDBs improve the shell-side fluid distribution effectively, but increase the shell-side pressure drop. The comparison shows that the fluid flow distributor with the best fluid flow distribution gives the largest pressure drop, about 10%-12% larger than that without FDB and about 4%-6% larger than that with other two FDBs. The largest pressure drop of shell side is generated in the regions of inlet and outlet.%对一种新型并流多通道进出口结构(MPC)轴流管壳式换热器壳程流场分布与阻力性能进行全面研究,分别研究了管排数、Reynolds数、不同挡板对壳程流场分布、阻力性能的影响,并且采用实验方法对数值模型与方法的正确性进行论证.研究结果表明,在无挡板的情况下,随着管排数的减小,壳程流场分布不均现象

  16. 三种管壳式换热器传热与流阻性能对比实验研究%Contrast Experimental Research on Heat Transfer and Flow Resistance Performance for Three Kinds of Shell--and--tube Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    古新; 董其伍; 王珂; 刘敏珊

    2012-01-01

    There are some disadvantages in segmental baffle heat exchanger for the transversal flow over tubes in its shell side,such as the high flow resistance,large heat transfer dead region,and so on. The fluid flows longitudinally in the shell side of rod baffle heat exchanger, but the heat transfer performance is not perfect when the Reynolds number in shell side is low. For overcoming above men- tioned disadvantages, a kind of new efficient and energy saving shell--and--tube heat exchanger with sideling flow in shell side was developed, the fluid flowed longitudinally in general, and the fluid in some local regions flowed over tubes inclinedly. Contrast experiments on heat transfer and flow resist- ance performances among this new kind of heat exchanger and segmental baffle heat exchanger, rod baffle heat exchanger were carried out, it is indicated that with the same fluid flow in shell side, the heat transfer coefficient,pressure drop, and over--all performance of sideling flow heat exchanger lie in between of those of segmental baffle heat exchanger and rod baffle heat exchanger. With this new kind of heat exchanger, the new technique and products are provided for the upgrade and update of shell--and--tube heat exchanger,and the important basis are also provided by research results for the structure selection and optimization design of heat exchangers in thermal system.%弓形折流板换热器壳程流体横向冲刷换热管时存在流动阻力大和传热死区大等缺点,折流杆换热器壳程流体纵向流动,但当壳程流体雷诺数Re较小时传热性能不佳。为克服上述缺点,研究开发了一种新型高效节能的斜向流管壳式换热器,该换热器壳程流体总体呈纵向流动,局部区域流体倾斜冲刷换热管束。对斜向流换热器与折流板换热器和折流杆换热器传热与流阻性能的对比实验研究表明,在同等壳程流体流量下,斜向流管壳式换热器的传热系数、压降和综合性能均

  17. Comparison and Analysis on Shell-and-tube Heat Exchanger of Regulator in Fuel Gas Power Plants%燃气电厂调压站管壳式换热器的比较与分析

    Institute of Scientific and Technical Information of China (English)

    魏驰

    2015-01-01

    目前用于燃气电厂调压站的换热器主要有国产单管式及进口双管式两种型式,文章主要从安全性和经济性两方面对这两种换热器进行比较、分析.%Two main styles of heat exchangers are mono-tube heat exchangers at home and double-tube heat exchangers abroad. The paper introduces two kinds of heat exchangers from the perspective of safety and economics.

  18. 多组螺旋叶片折流板换热器性能试验研究%Experiment Research on Heat Transfer Performance in Multiple Sets of Shell and Tube Heat Exchangers With Spiral Blade Baffles

    Institute of Scientific and Technical Information of China (English)

    李林; 高磊; 张莹莹; 黄伟

    2013-01-01

    The test of heat transfer performance was carried out in five the spiral blade baffles heat exchangers, and their shell heat transfer and pressure drop were compared. Through analysis and regression calculation of experimental data, experience formulas of shell-side heat transfer coefficient and pressure drop were obtained. This result could provide a reference for numerical simulation and design of spiral blade baffles heat exchangers.%  进行了5组参数下螺旋叶片折流板换热器传热性能试验,对比壳程传热和压降性能,并对试验数据进行回归计算,获得其壳程传热系数和压力降的经验计算公式。结果可为螺旋叶片折流板换热器系统模拟和设计计算提供参考。

  19. 单弓折流板管壳式换热器壳程局部传热及流阻研究%Study on shell-side local heat transfer and flow resistance of shell-and-tube heat exchanger with arc baffles

    Institute of Scientific and Technical Information of China (English)

    黄阔

    2012-01-01

    The local heat transfer performance, local flow velocity and resistance of shell-and-tube heat exchanger with arc baffles are studied. The measurement result indicates that the change rules of the local heat transfer coefficient of tube bundle and velocity of gas flow in shell-side are consistent. The twenty-four measuring positions are selected suitably, and can reflect the change rules of the local heat transfer and velocity of gas flow. The relevance equations between the average Nu and Re number, and the flow resistance coefficient f and Re number in shell-side of the heat exchanger are summarized, so it provide the reference for designing this kind of heat exchangers.%对半圆形单弓折流板管壳式换热器壳侧局部传热性能、局部流速及阻力进行了实验研究,测量结果表明,其壳侧局部传热膜系数的变化规律与相应点速率变化规律相一致.所取24个测量位置点分布较为合理,基本上反映了换热器局部相应换热及流场分布规律.同时归纳出换热器壳侧的平均努塞尔准数Nu与雷诺准数Re的关联式及流动阻力系数f与雷诺准数Re的关联式,为换热器的实际运用提供了参考依据.

  20. Automatización y optimización del diseño de intercambiadores de calor de tubo y coraza mediante el método de Taborek//Automatization and optimization of shell and tube heat exchangers design using the method of Taborek

    Directory of Open Access Journals (Sweden)

    Maida Bárbara Reyes‐Rodríguez

    2014-01-01

    Full Text Available Los intercambiadores de calor del tipo de coraza y tubo constituyen la parte más importante de los equipos de transferencia de calor sin combustión en las plantas de procesos químicos. Existen en la literatura numerosos métodos para el diseño de Intercambiadores de calor de tubo y coraza. Entre los más conocidos se encuentran el Método de Kern, el Método de Bell Delaware, el Método de Tinker, elMétodo de Wills and Johnston y el Método de Taborek. El presente trabajo tiene como objetivo describir y automatizar el método de Taborek. Se realiza además la optimización del Costo del Intercambiador de Calor mediante el método de Recocido Simulado y el método de los algoritmos genéticos. Se puede concluir que la optimización por ambos métodos arroja resultados similares, disminuyendoapreciablemente el costo del intercambiador optimizado.Palabras claves: optimización, intercambiadores de calor, método de Taborek, algoritmos genéticos.______________________________________________________________________________AbstractShell and tube heat exchangers are the most important equipment for heat transfer without combustion in plants of chemical processes.There are many methods for designing shell and tube heat exchangers in literature. Among the most known are the Kern´s Method, the Method of Bell Delaware, the Method ofTinker, the Method of Wills and Johnston and the Method of Taborek. The objective of this paper is to describe and automate the Taborek´s method. It is also realized and optimization of the heat exchanger cost using the genetic algorithm and Simulated Annealing. It can be concluded that the optimization usingboth methods conduces to similar results, diminishing considerably the optimized exchanger cost.Key words: optimization, Heat Exchangers, Taborek, Genetic Algorithms.

  1. 螺旋折流板换热器的协同角分布特性及局部换热特征%Field synergy angle distribution and local heat transfer characteristic in shell and tube heat exchanger with helical baffles

    Institute of Scientific and Technical Information of China (English)

    张剑飞; 陶文铨; 何雅玲

    2013-01-01

    Three dimensional numerical simulation and field synergy principle analysis were conducted with simplified periodic models for shell and tube heat exchangers with helical baffles at three helix angles (30°,40°and 50°),and commercial codes of GAMBIT 2.3 and FLUENT 6.3 were adopted in the simulation.It is found that Nusselt number from the model with 40° angle is the largest and the predicted average field synergy intersection angle is the smallest,which is consistent with the field synergy principle.The distribution characteristics of field synergy angles reveal that the distribution is quite uniform through whole shell side of the exchangers.The investigation on local heat transfer characteristics in different regions on the shell side shows that the heat transfer rate in the central region of the heat exchanger increases with the increase of Reynolds number.%采用商用软件GAMBIT和FLUENT对3种不同螺旋角的螺旋折流板换热器周期性模型进行了三维数值模拟计算分析.计算发现40°角模型的Nusselt数最高而平均协同角最小,结论符合场协同原理.揭示了螺旋折流板换热器内场协同角的分布特征,发现螺旋折流板换热器整场的场协同角分布相当均匀.同时,对螺旋折流板换热器内不同区域的局部换热特征进行了研究,发现中心区域的换热强度随Reynolds数逐渐增强.

  2. Simulation Analysis of Shell Structures of Shell and Tube Heat Exchanger Based on CFD Technology%利用CFD技术对管壳式换热器壳程结构的模拟分析

    Institute of Scientific and Technical Information of China (English)

    冯涛; 孟凡英; 赫靓; 陈雪波

    2012-01-01

    Using CFD technology.a waifrsource lieul pump's evaporator shell wilh quantity Qa = 180 kW ts made of fluid flow and temperature ii'-l'l simulation and analysis. It's found thai;I ) In ihe original design,lhere are a lol of single segmeiilal.wilh thick baffle plate that 00-I'upics somp effect heal transfer area,influencing the stall side heal eschanpe pff'T.-l and greatly dropping the waier pressure;2) because nf the temperature difference between water and the I-vaporation If mperalure of refrigeranl, larger thermal stress is produced, wilh possibility of breakage in lube plufe and tube heat exchanger ;3) liased on B(>erd vector analysis of ihe original design, it's easy to find lots of dead zone in the original design,whifb will afiHct the water side heal exchanger. According ti) ihese rpsulls,corresponding solulions are pii! Forward,rstub-tishing the impnived evaporator model.%以某公司所制造的水源热泵为基础,针对制冷量Q0=180 kW的蒸发器的内部结构,利用CFD技术对其壳程侧做了流场与热场的模拟分析,得到了具有一定价值的分析结果:1)原设计中不仅单弓形折流板的数量较多而且折流板较厚,占用了一定有效换热面积,势必影响了壳程水侧的换热效果和造成了较大压降;2)由于进水管侧的水温与制冷剂的蒸发温度之间存在较大的温差,会在管板上产生较大的热应力,有造成管板与换热管的接触破坏的可能;3)通过对原设计的速度矢量分析,可以较为清楚地看到,原设计存在较多的流动死区,这些流动死区,会影响水侧换热.根据这些分析结果,提出了相应地解决方案,并建立了改进后的蒸发器模型.

  3. 管壳式换热器壳程特性的数值模拟研究%Numerical Simulation Research on Features in Shell Side of Shell-and-Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    廖国进; 张军强

    2012-01-01

      Three dimensional numerical simulations of one tube-and-shell heat exchanger were carried out by using the FLUENT software. The influences caused by the segmental baffle number, inlet flow rate and baffle nick’s height on the pressure drop and outlet temperature of the tube-and-shell heat exchanger’s shell side, were analyzed. The results expatiate as the segmental baffle number increases, the pressure drop and outlet temperature increase, and that as the inlet flow rate increases, the pressure drop increases with dropping tendency quickening, but the outlet temperature is dropping, and that as the segmental baffle nick’s height increases, the pressure drop and the outlet temperature decrease, and the pressure drop rate tends to slow down. And under the same pressure drop condition, it’s better to change the baffle number to increase the outlet temperature than to change the inlet flow rate and baffle nick’s height.%  利用 FLUENT 软件对一管壳式换热器壳程流场进行了三维数值模拟,分析研究了折流板数目、进口流速和折流板缺口高度对换热器壳程压降、出口温度的影响,结果显示,随着折流板数目增加,壳程压降和出口温度逐渐增大;随着进口流速增大,壳程压降逐渐增大且趋势加快,而出口平均温度下降,但是温度下降不大;随着折流板缺口高度增大,壳程压降和出口平均温度逐渐减小,但是压降减小逐渐趋于缓和;相同的压降条件下,通过改变折流板数目提高出口温度比改变进口流速和折流板缺口高度更有效

  4. Numerical Study on the Thermal Performance of a Shell and Tube Phase Change Heat Storage Unit during Melting Process

    Directory of Open Access Journals (Sweden)

    Wei Li

    2014-11-01

    Full Text Available This work presents a numerical study of the thermal performance in a shell and tube phase change heat storage unit. Paraffin wax as phase change material (PCM is filled in the shell space. The heat transfer fluids (HTFs: air and water flow through the tube and transfer the heat to PCM. A mathematical model involving HTF and PCM is developed to analyze the thermal performance of the phase change heat storage unit and is validated with experimental data. Numerical investigation is conducted to evaluate the effect of HTF inlet velocity on the HTF outlet temperature, Nu, and melt fraction when air or water is used as HTF. Results indicate that the air inlet velocity has a great effect on the air outlet temperature and heat transfer rate, and the water inlet velocity has little effect on the water outlet temperature. The investigated results can provide a reference for designing phase change heat storage system.

  5. An experimental investigation of shell and tube latent heat storage for solar dryer using paraffin wax as heat storage material

    Directory of Open Access Journals (Sweden)

    Ashish Agarwal

    2016-03-01

    Full Text Available In the presented study the shell and tube type latent heat storage (LHS has been designed for solar dryer and paraffin wax is used as heat storage material. In the first part of the study, the thermal and heat transfer characteristics of the latent heat storage system have been evaluated during charging and discharging process using air as heat transfer fluid (HTF. In the last section of the study the effectiveness of the use of an LHS for drying of food product and also on the drying kinetics of a food product has been determined. A series of experiments were conducted to study the effects of flow rate and temperature of HTF on the charging and discharging process of LHS. The temperature distribution along the radial and longitudinal directions was obtained at different time during charging process to analyze the heat transfer phenomenon in the LHS. Thermal performance of the system is evaluated in terms of cumulative energy charged and discharged, during the charging and discharging process of LHS, respectively. Experimental results show that the LHS is suitable to supply the hot air for drying of food product during non-sunshine hours or when the intensity of solar energy is very low. Temperature gain of air in the range of 17 °C to 5 °C for approximately 10 hrs duration was achieved during discharging of LHS.

  6. Enhanced shell-and-tube heat eschangers for the power and process industries. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bergles, A.E.; Jensen, M.K.; Somerscales, E.F.; Curcio, L.A. Jr.; Trewin, R.R.

    1994-08-01

    Single-tube pool boiling tests were performed with saturated pure refrigerants and binary mixtures of refrigerants. Generally, with pure refrigerants, the High Flux surface performed better at the higher heat fluxes compared to the Turbo-B tube, and both enhanced surfaces performed significantly better than smooth surface. In tests of R-11/R-113 mixtures, the enhanced surfaces had much less degradation in heat transfer coefficient due to mixture effects compared to smooth tubes; the largest degradation occurred at a mixture of 25% R-11/75% R-113. Under boiling in saturated aqueous solution of calcium sulfate, with a single tube, effects of fouling were more pronounced at the higher heat fluxes for all surfaces. Two staggered tube bundles were tested with tube pitch-diameter ratios of 1.17 and 1.50. For the pure refrigerant, tests on the smooth-tube bundle indicated that the effects on the heat transfer coefficient of varying mass flux, quality, and tube-bundle geometry were small, except at low heat fluxes. Neither enhanced surface showed any effect with changing mass flux or quality. The binary mixture bundle-boiling tests had results that were very similar to those obtained with the pure refrigerants. When boiling a refrigerant-oil mixture, all three surfaces (smooth, High Flux, and Turbo-B) experienced a degradation in its heat transfer coefficient; no surface studied was found to be immune or vulnerable to the presence of oil than another surface.

  7. The evaluation of a small capacity shell and tube ammonia evaporator

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Valladares, O.; Hernandez, J.I.; Best y Brown, R. [Centro de Investigacion en Energia de la UNAM, Morelos (Mexico); Gonzalez, J.C. [Universidad Autonoma de Campeche (Mexico). Programa CADETRAA

    2003-12-01

    The use of ammonia as refrigerant is widespread in vapour compression and ammonia/water absorption systems. Ammonia is not actually used in low capacity applications mainly because of the lack of economical available equipment. For this reason, the objective of this study is the numerical and experimental evaluation of a small capacity ammonia shell and tube evaporator with enhanced heat transfer surfaces. An experimental system to evaluate small capacity heat exchangers was developed. A shell and tube evaporator with external low fin tubes was successfully tested. The experimental uncertainty for the evaporator capacity has been estimated within {+-}5.5%. The experimental results were used to validate a heat exchanger numerical tool that predicts reasonably well the cooling capacity and load outlet temperatures. The methodology presented in this work can be applied to evaluate other refrigerants in similar shell and tube evaporators and to optimize the design of an evaporator for a specific application. (author)

  8. COMPARATIVEANALYSIS OF ADVANCED CONTROLLERS IN A HEAT EXCHANGER

    OpenAIRE

    P. Sivakumar

    2013-01-01

    Temperature control of the shell and tube heat exchanger is characteristics of nonlinear, time varying and time lag. Since the temperature control with conventional PID controller cannot meet a wide range of precision temperature control requirement, we design temperature control system of the shell and tube heat exchanger by combining fuzzy and PID control methods in this paper. The simulation and experiments are carried out; making a comparison with conventional PID control showing that fuz...

  9. Boiling heat-transfer coefficient variation for R407C inside horizontal tubes of a refrigerating vapour-compression plant's shell-and-tube evaporator

    Energy Technology Data Exchange (ETDEWEB)

    Torrella, Enrique [Department of Applied Thermodynamics, Camino de Vera, 14, Polytechnic University of Valencia, E-46022 Valencia (Spain); Navarro-Esbri, Joaquin; Cabello, Ramon [Department of Technology, Campus de Riu Sec,University Jaume I, E-12071 Castellon (Spain)

    2006-03-01

    The present paper presents experimental results obtained from a refrigerating vapour-compression plant's shell-and-tube (1-2) evaporator working with R407C. Several tests have been carried out to study the influence of the evaporating pressure and the refrigerant's mass flow rate on the refrigerant's boiling heat-transfer coefficient inside horizontal tubes. This work has been performed by analyzing the variations of the evaporator's overall thermal-resistance, computed using the effectiveness-NTU method, considering the influence of pressure drops and glide at the evaporator, and finally transferring the results and conclusions to the boiling heat-transfer coefficient. It has been observed that the variations of the boiling heat-transfer coefficient show a dependence on the evaporating temperature and the refrigerant's mass-flow rate, which has been analyzed in the test range. [Author].

  10. 管壳式换热器中旋流片强化管外传热的数值模拟%NUMERICAL SIMULATION OF HEAT TRANSFER ENHANCEMENT BY TWISTED LEAF IN SHELL SIDE OF SHELL-AND-TUBE HEAT EXCHANGER

    Institute of Scientific and Technical Information of China (English)

    周水洪; 邓先和; 徐伟

    2007-01-01

    As a new type of heat transfer augmentation element, twisted-leaf tube bundle support was conducted. Based on the experimental investigation, a shell-side periodic unit channel model of the longitudinal flow type heat exchanger was developed for numerical simulation to analyze the flow and heat transfer information of swirl flow induced by twisted leaf.The section-by-section performance evaluation factors were used to analyze the mechanism of heat transfer enhancement. The results demonstrate that the twisted leaf can produce a helical flow, resulting in the disruption of the continuity and stability of the fluid. The disturbing flow can promote turbulent intensity and enhance heat transfer effectively. The twistedleaf section gives worst integrated performance with a big increase in both heat transfer and pressure loss, and the trail-flow section also has no good performance because of the decayed swirl flow. The free-swirl-flow section provides the best performance with high efficiency and low pressure loss. In order to improve the integrated performance along the whole heat exchanger, it is recommended to optimize the shell side structure parameters to fully use the free swirl flow.%提出并分析了一种新型的传热强化元件--旋流片作为管壳式换热器管隙间支撑物的传热强化机理.在实验基础上,采用周期性单元流道模型数值模拟了旋流片产生的衰减性自旋流的流动和传热特性,并采用分段综合因子分析了传热强化的机理.结果显示,旋流片能起到扰流作用,并使流体强烈地冲刷传热管壁面强化传热.有旋流片段的综合因子最小,尾流段的综合因子接近于1,在自旋流段的综合因子最佳,应当充分利用自旋流段低阻高效的特点对换热器进行优化.

  11. A core alternative[Heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, R.H. [Chart Heat Exchangers, Wisconsin (United States)

    2001-09-01

    The development of the efficient Core-in-kettle heat exchangers by Chart Heat Exchangers as an alternative to shell and tube exchangers is reported, and its use as condensers and reboilers in ethylene plants and refrigerant condensers and chillers in natural gas processing and liquid natural gas (LNG) plants are discussed. The novel technology is described with details given of the replacement of the tube bundle with a Chart brazed aluminium plate-fin heat exchanger core, the operation of the exchanger, the savings achieved by installing these heat exchangers in new or existing plants, and Core-in-Kettle retrofits of existing shell and tube heat exchangers. The limitations of the use of Core-in-Kettle heat exchangers to clean fluids typical of hydrocarbon processing, and temperature and pressure limitations are noted.

  12. A Project to Design and Build Compact Heat Exchangers

    Science.gov (United States)

    Davis, Richard A.

    2005-01-01

    Students designed and manufactured compact, shell-and-tube heat exchangers in a project-based learning exercise integrated with our heat transfer course. The heat exchangers were constructed from common building materials available at home improvement centers. The cost of materials for a device was less than $20. The project gave students…

  13. Optimization of a Shell and Tube Condenser using Numerical Method

    Directory of Open Access Journals (Sweden)

    Pradeep Wagh

    2015-07-01

    Full Text Available The purpose of this study was to investigate the effect of installation of the tube external surfaces, their parameter and variable in a shell-and-tube condenser. Variation of heat transfer coefficient with each variable of shell and tube condenser was measured each test. The optimization tube outside diameter size was analyzed and use extended surface area attached tube with tube material and tube layout and arrangement (Number of tube a triangular or hexagonal arrangement on shell-and tube condenser. The computer programming was used to get faster output in less time. Results suggest that mean heat transfer coefficient in variable condition were mainly at velocity is fixed. And also average additional surfaces and tube layout and the arrangement comparison with the quantity of the heat transfer.

  14. 换热器壳程结构的实验研究及节能分析%An Experimental Study and Energy Saving Analysis of Shell-side Structure for Shell-and-tube Exchanger

    Institute of Scientific and Technical Information of China (English)

    邹静; 曾力丁; 于洋; 郑伟业; 朱冬生

    2011-01-01

    为对管壳式换热器不同壳程结构进行实验研究,设计建造了普通单弓形折流板圆管换热器和无折流板的椭圆扭曲管换热器实验台。通过测试换热器管壳两侧的传热系数、压降和换热量等参数,对比分析了两种不同壳程结构的换热器在相同尺寸下、相同工况的传热性能。实验结果表明椭圆扭曲管管侧的表面传热系数比普通圆管和折流板换热器均有大幅度提高,随雷诺数的增大,管内表面传热系数约为普通圆管的1.27~1.43倍,管外壳程表面传热系数约为普通圆管的1.36~1.76倍,能够有效提高换热效率。另外与传统的单弓形折流板换热器相比,壳程压降显著减小,约为折流板换热器的30~35%。椭圆扭曲管换热器既强化了管内传热,又减小了壳程压降,是一种非常有效的提高换热效率的手段。综合比较管壳侧的传热效率,发现在低雷诺数工况椭圆扭曲管换热器的节能效果更好。%A test platform of shell-and-tube exchanger was designed and established to conduct an experimental research.With the same size and operating condition,heat transfer properties including pressure drop and heat transfer coefficient of heat transfers with twisted tubes,plain tubes and baffles were analyzed and compared.The experimental result indicated that heat transfer coefficient of twisted tubes has been vastly improved.As Reynolds number adding,tube-side heat transfer coefficient of twisted tube bundle is about 1.27 to 1.43 times that of plain tubes,also its shell-side heat transfer coefficient is as about 1.36 to 1.76 times as plain tubes.And compared with traditional single segmental baffled heat exchanger,the pressure drop of twisted tube heat exchanger decreased significantly.It's about 30 to 35 percent of baffled heat exchanger varying with different Reynolds number.Due to its higher heat transfer coefficient in tubes,lower pressure drop in shell,twisted elliptic tubes

  15. Simplified calculation of vibrations in shell and tube heat exchangers with liquids

    OpenAIRE

    Maida Bárbara Reyes-Rodríguez; Jorge Laureano Moya-Rodríguez; Rafael Goytisolo-Espinosa

    2014-01-01

    Un problema muy serio a tener en cuenta en el diseño mecánico de los intercambiadores de calor de tubo y coraza son las vibraciones inducidas en los tubos por el paso del fluido. La vibración de los tubos de los intercambiadores de calor de tubo y coraza es un factor que limita de manera importante la operación de estos equipos. Los procesos dinámicos de los fluidos no estacionarios que ocurren durante el flujo producen vibraciones. Éstas son pulsaciones turbulentas de la presión (flujo turbu...

  16. Computation of two-dimensional isothermal flow in shell-and-tube heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Carlucci, L.N.; Galpin, P.F.; Brown, J.D.; Frisina, V.

    1983-07-01

    A computational procedure is outlined whereby two-dimensional isothermal shell-side flow distributions can be calculated for tube bundles having arbitrary boundaries and flow blocking devices, such as sealing strips, defined in arbitrary locations. The procedure is described in some detail and several computed results are presented to illustrate the robustness and generality of the method. 11 figs.

  17. Rancang Bangun Alat Penukar Kalor Tipe Shell and Tube Satu Laluan Cangkang Dua Laluan Tabung Sebagai Pemanas Air Untuk Air Mandian Dengan Fluida Panas Air Belerang

    OpenAIRE

    Sihombing, Jackson

    2016-01-01

    Heat exchanger is a device that produces heat transfer from one fluid to another fluid. This study was conducted to design a heat exchanger shell and tube type that can be applied as a water heater for the shower water to the sulfur hot spring in Semangat Gunung village, Tanah Karo, with hot fluid sulfur water. Heat exchanger designed with a shell passes and two passes tubes. The hot fluid (sulfur water) will flow through the shell and the cold fluid (water) flowing through the tube. For the ...

  18. Experimental Investigation Of Heat Transfer Characteristics Of Nanofluid Using Parallel Flow, Counter Flow And Shell And Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Dharmalingam R.

    2015-12-01

    Full Text Available Chłodzenie jest niezbędne dla właściwego funkcjonowania i niezawodności różnorodnych produktów, jak urządzenia elektroniczne, komputery, samochody, systemy laserowe wielkiej mocy, itp. W sytuacji wzrostu obciążenia cieplnego i strumieni ciepła wytwarzanych przez urządzenia przemysłowe, chłodzenie jest jednym z najważniejszych wyzwań występujących w różnych gałęziach przemysłu, transporcie, mikroelektronice, itp. Płynami, które zwykle są używane do odprowadzania ciepła z tych urządzeń są woda, glikol etylenowy i oleje. Nanopłyny, opracowane w ostatnim czasie, wykazują generalnie lepsze charakterystyki przewodnictwa cieplnego niż woda. Przedstawiona praca stanowi podsumowanie badań doświadczalnych nad wymuszonym, konwekcyjnym odprowadzaniem ciepła i charakterystykami przepływu nanopłynu składającego się z wody i cząsteczek Al2O3 (w 1% stężeniu objętościowym w warunkach laminarnego przepływu współprądowego i przeciwprądowego w płaszczowych i rurowych wymiennikach ciepła. W przedstawionych badaniach użyto cząstek Al2O3 o średnicy ok. 50 nm. Wybrano trzy różne prędkości przepływu masy, opisano wyniki eksperymentów. Wyniki te wskazują, że całkowity współczynnik odprowadzania ciepła i bezwymiarowa liczba Nusselta nanopłynu są, przy tej samej prędkości przepływu masy i temperaturze na wlocie, nieznacznie wyższe, niż dla samego płynu bazowego. Z wyników doświadczalnych wynika, że całkowity współczynnik odprowadzania ciepła wzrasta wraz z prędkością przepływu masy. Pokazano, że gdy wzrasta prędkość przepływu masy, całkowity współczynnik odprowadzania ciepła wraz z bezwymiarową liczbą Nusselta ostatecznie wzrastają, niezależnie od kierunku przepływu. Stwierdzono także, że ze wzrostem prędkości przepływu masy wartość LMTD (średniej logarytmicznej różnicy temperatur ostatecznie maleje, niezależnie od kierunku przepływu.

  19. Direct contact liquid-liquid heat exchanger for solar-heated and cooled buildings

    Science.gov (United States)

    Karaki, S.; Brothers, P.

    1980-06-01

    The procedure used was to obtain experimental performance data from a solar system using a DCLLHE for both heating and cooling functions, develop a simulation model for the system, validate the model using the data, apply the model in five different climatic regions of the country for a complete year, and estimate the life-cycle cost of the system for each application. The results are compared to a conventional solar system, using a standard shell-and-tube heat exchanger.

  20. Demonstration of leapfrogging for implementing nonlinear model predictive control on a heat exchanger.

    Science.gov (United States)

    Sridhar, Upasana Manimegalai; Govindarajan, Anand; Rhinehart, R Russell

    2016-01-01

    This work reveals the applicability of a relatively new optimization technique, Leapfrogging, for both nonlinear regression modeling and a methodology for nonlinear model-predictive control. Both are relatively simple, yet effective. The application on a nonlinear, pilot-scale, shell-and-tube heat exchanger reveals practicability of the techniques.

  1. A computational fluid dynamics model for designing heat exchangers based on natural convection

    NARCIS (Netherlands)

    Dirkse, M.H.; Loon, van W.K.P.; Walle, van der T.; Speetjens, S.L.; Bot, G.P.A.

    2006-01-01

    A computational fluid dynamics model was created for the design of a natural convection shell-and-tube heat exchanger with baffles. The flow regime proved to be turbulent and this was modelled using the k¿¿ turbulence model. The features of the complex geometry were simplified considerably resulting

  2. Heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Craig, L.B.; Farma, A.J.

    1987-01-06

    This invention concerns a heat exchanger as used in a space heater, of the type in which hot exhaust gases transfer heat to water or the like flowing through a helical heat exchange coil. A significant improvement to the efficiency of the heat exchange occurring between the air and water is achieved by using a conduit for the water having external helical fluting such that the hot gases circulate along two paths, rather than only one. A preferred embodiment of such a heat exchanger includes a porous combustion element for producing radiant heat from a combustible gas, surrounded by a helical coil for effectively transferring the heat in the exhaust gas, flowing radially from the combustion element, to the water flowing through the coil. 4 figs.

  3. Multidimensional numerical modeling of heat exchangers

    Science.gov (United States)

    Sha, W. T.; Yang, C. I.; Kao, T. T.; Cho, S. M.

    A comprehensive, multidimensional, thermal-hydraulic model is developed for the analysis of shell-and-tube heat exchangers for liquid-metal services. For the shellside fluid, the conservation equations of mass, momentum, and energy for continuum fluids are modified using the concept of porosity, surface permeability and distributed resistance to account for the blockage effects due to the presence of heat-transfer tubes, flow baffles/shrouds, the support plates, etc. On the tubeside, the heat-transfer tubes are connected in parallel between the inlet and outlet plenums, and tubeside flow distribution is calculated based on the plenum-to-plenum pressure difference being equal for all tubes. It is assumed that the fluid remains single-phase on the shell side and may undergo phase-change on the tube side, thereby simulating the conditions of Liquid Metal Fast Breeder Reactor (LMFBR) intermediate heat exchangers (IHX) and steam generators (SG).

  4. Numerical Analysis of Shell-and-Tube Type Latent Thermal Energy Storage Performance with Different Arrangements of Circular Fins

    Directory of Open Access Journals (Sweden)

    Sebastian Kuboth

    2017-02-01

    Full Text Available Latent thermal energy storage (LTS systems are versatile due to their high-energy storage density within a small temperature range. In shell-and-tube type storage systems fins can be used in order to achieve enhanced charging and discharging power. Typically, circular fins are evenly distributed over the length of the heat exchanger pipe. However, it is yet to be proven that this allocation is the most suitable for every kind of system and application. Consequently, within this paper, a simulation model was developed in order to examine the effect of different fin distributions on the performance of shell-and-tube type latent thermal storage units at discharge. The model was set up in MATLAB Simulink R2015b (The MathWorks, Inc., Natick, MA, USA based on the enthalpy method and validated by a reference model designed in ANSYS Fluent 15.0 (ANSYS, Inc., Canonsburg, PA, USA. The fin density of the heat exchanger pipe was increased towards the pipe outlet. This concentration of fins was implemented linearly, exponentially or suddenly with the total number of fins remaining constant during the variation of fin allocations. Results show that there is an influence of fin allocation on storage performance. However, the average storage performance at total discharge only increased by three percent with the best allocation compared to an equidistant arrangement.

  5. Study of a Multi-phase Hybrid Heat Exchanger-Reaction (HEX Reactor): Part 1 - Experimental Characterization

    Science.gov (United States)

    2014-01-01

    scalability, and mixing capability compared to more traditional shell - in- tube heat exchangers or stirred tank batch reactors. This study explores the... tube heat exchangers or stirred tank batch reactors. This study explores the hydrodynamic behavior of gas-evolving reacting flows in chevron plate heat ...thermal performance and ease of maintenance. PHEs can be easily disassembled for inspection andmaintenance (in con- trast, shell -and- tube heat

  6. TO DEDUCTION OF MASS FLOW RATE FOR HELICAL HEAT EXCHANGER AT MULTIPLE CROSS-SECTIONS USING CFD

    OpenAIRE

    Surendra Kumar Vishwakarma*, Sanjay Kumbhare, K.K. Thakur

    2016-01-01

    Enhancing the heat transfer by the use of helical coils has been studied and researched by many researchers, because the fluid dynamics inside the pipes of a helical coil heat exchanger offer certain advantages over the straight tubes, shell and tube type heat exchanger, in terms of better heat transfer and mass transfer coefficients. Various configurations of coil structure are possible, and the configuration in which there is a series of vertically stacked helically coiled tubes is the most...

  7. Development of a Minichannel Compact Primary Heat Exchanger for a Molten Salt Reactor

    OpenAIRE

    Lippy, Matthew Stephen

    2011-01-01

    The first Molten Salt Reactor (MSR) was designed and tested at Oak Ridge National Laboratory (ORNL) in the 1960â s, but recent technological advancements now allow for new components, such as heat exchangers, to be created for the next generation of MSRâ s and molten salt-cooled reactors. The primary (fuel salt-to-secondary salt) heat exchanger (PHX) design is shown here to make dramatic improvements over traditional shell-and-tube heat exchangers when changed to a compact heat exchanger de...

  8. Analysis of the heat transfer in double and triple concentric tube heat exchangers

    Science.gov (United States)

    Rădulescu, S.; Negoiţă, L. I.; Onuţu, I.

    2016-08-01

    The tubular heat exchangers (shell and tube heat exchangers and concentric tube heat exchangers) represent an important category of equipment in the petroleum refineries and are used for heating, pre-heating, cooling, condensation and evaporation purposes. The paper presents results of analysis of the heat transfer to cool a petroleum product in two types of concentric tube heat exchangers: double and triple concentric tube heat exchangers. The cooling agent is water. The triple concentric tube heat exchanger is a modified constructive version of double concentric tube heat exchanger by adding an intermediate tube. This intermediate tube improves the heat transfer by increasing the heat area per unit length. The analysis of the heat transfer is made using experimental data obtained during the tests in a double and triple concentric tube heat exchanger. The flow rates of fluids, inlet and outlet temperatures of water and petroleum product are used in determining the performance of both heat exchangers. Principally, for both apparatus are calculated the overall heat transfer coefficients and the heat exchange surfaces. The presented results shows that triple concentric tube heat exchangers provide better heat transfer efficiencies compared to the double concentric tube heat exchangers.

  9. Thermal design of multi-fluid mixed-mixed cross-flow heat exchangers

    Science.gov (United States)

    Roetzel, W.; Luo, X.

    2010-11-01

    A fast analytical calculation method is developed for the thermal design and rating of multi-fluid mixed-mixed cross-flow heat exchangers. Temperature dependent heat capacities and heat transfer coefficients can iteratively be taken into account. They are determined at one or two special reference temperatures. Examples are given for the application of the method to the rating of special multi-fluid multi-pass shell-and-tube heat exchangers and multi-fluid cross-flow plate-fin heat exchangers. The accuracy of the method is tested against numerical calculations with good results.

  10. Deposition of dairy protein-containing fluids on heat exchange surfaces.

    Science.gov (United States)

    Rakes, P A; Swartzel, K R; Jones, V A

    1986-12-01

    The deposition behavior of milk and dairy protein model systems under turbulent flow conditions (Re > 66,700) was observed in the heating sections of a tubular ultra-high temperature processing unit. This phenomenon was monitored via thermal resistance of the deposit in four segments in each of two shell-and-tube heat exchangers. Model systems were comprised of mixtures of sodium caseinate, whey proteins, salts, lactose, and fat. Fouling rates varied with type of milk protein, heater wall temperature, and location in the heat exchangers. The relationship between deposition rate in the heat exchanger and protein denaturation kinetics was also examined.

  11. Various methods to improve heat transfer in exchangers

    Directory of Open Access Journals (Sweden)

    Pavel Zitek

    2015-01-01

    Full Text Available The University of West Bohemia in Pilsen (Department of Power System Engineering is working on the selection of effective heat exchangers. Conventional shell and tube heat exchangers use simple segmental baffles. It can be replaced by helical baffles, which increase the heat transfer efficiency and reduce pressure losses. Their usage is demonstrated in the primary circuit of IV. generation MSR (Molten Salt Reactors. For high-temperature reactors we consider the use of compact desk heat exchangers, which are small, which allows the integral configuration of reactor. We design them from graphite composites, which allow up to 1000°C and are usable as exchangers: salt-salt or salt-acid (e.g. for the hydrogen production. In the paper there are shown thermo-physical properties of salts, material properties and principles of calculations.

  12. Various methods to improve heat transfer in exchangers

    Science.gov (United States)

    Pavel, Zitek; Vaclav, Valenta

    2015-05-01

    The University of West Bohemia in Pilsen (Department of Power System Engineering) is working on the selection of effective heat exchangers. Conventional shell and tube heat exchangers use simple segmental baffles. It can be replaced by helical baffles, which increase the heat transfer efficiency and reduce pressure losses. Their usage is demonstrated in the primary circuit of IV. generation MSR (Molten Salt Reactors). For high-temperature reactors we consider the use of compact desk heat exchangers, which are small, which allows the integral configuration of reactor. We design them from graphite composites, which allow up to 1000°C and are usable as exchangers: salt-salt or salt-acid (e.g. for the hydrogen production). In the paper there are shown thermo-physical properties of salts, material properties and principles of calculations.

  13. State-of-the-art survey of joinability of materials for OTEC heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Beaver, R. J.

    1978-12-01

    Literature and industrial sources were surveyed to assess, on the basis of apparent economics and reliability, the joinability of both shell-and-tube and compact ocean thermal energy conversion (OTEC) heat exchangers. A no-leak requirement is mandatory to prevent mixing seawater and the ammonia working fluid. The operating temperature range considered is 7 to 28/sup 0/C (45 to 82/sup 0/F). Materials evaluated were aluminum, titanium, copper--nickel, AL-6X austenitic stainless steel, singly and in combination with steel and concrete. Many types of welding and brazing processes, roller expansion, magnaforming, O-ring sealing, and adhesive bonding were considered. The automatic gas tungsten-arc welding process and explosion welding processes are the only two joining processes that now appear to offer the high reliability required of no-leak shell-and-tube heat exchangers. Of these two processes, the gas tungsten-arc welding process appears to be the more economically attractive.

  14. Segmented heat exchanger

    Science.gov (United States)

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  15. Selection and costing of heat exchangers

    Science.gov (United States)

    1992-12-01

    ESDU 92013 gives guidance on the selection of heat exchanger types for a given duty against various criteria; they include the general characteristics, together with such detailed aspects as the ranges of pressure and temperature appropriate, compatibility with the fluids involved, space and weight requirements, and cleaning accessibility and maintenance. That allows an initial choice to be made from 18 principal types of exchangers. The various types are all illustrated. A final choice can then be made between the feasible types on the basis of costs. Detailed costing data provided by manufacturers are tabulated as a function of heat load, operating pressure and the types of cold- and hot-side fluids for the following types of exchangers: shell-and-tube, double-pipe, printed-circuit, plate-fin, air-cooled and welded plate. Costing data are also tabulated as a function of heat load and the types of cold- and hot-side fluids for gasketed-plate exchangers. Seven worked examples of selection based on technical suitability and using the tabulated cost data illustrate fully the use of the information.

  16. Numerical Simulation of Tube Heat Exchanger and Oblique Flow Heat Exchanger Research%管壳式换热器数值模拟与斜向流换热器研究

    Institute of Scientific and Technical Information of China (English)

    付小亮; 张伟

    2014-01-01

    From a theoretical perspective , this paper analyzed the numerical simulation of shell-and-tube heat exchanger on the basis of experiments , and expounded its heat transfer enhancement .%笔者从理论的角度出发,在实验的基础上,对管壳式换热器的数值模拟进行了分析,并对它的传热强化进行了阐述。

  17. 基于VB技术的管壳式换热器传热计算系统开发%Development of heat transfer calculation system of tube shell heat exchanger based on VB technology

    Institute of Scientific and Technical Information of China (English)

    冯婕; 朱小军

    2016-01-01

    VB technology development shell and tube heat exchanger computing systems,is an innovative theory and practice,to improve computational efficiency of heat transfer heat exchanger has a great significance.This paper analyzes the Heat Exchanger computing systems,as well as technology in the VB Shell and Tube Heat Exchanger computing systems development.%运用VB技术开发管壳式换热器传热计算系统,是一种理论上和实践上的创新,对提高我国的换热器传热计算效率具有重要的意义。本文主要分析了换热器的传热计算系统,以及VB技术在管壳式换热器传热计算系统开发中的应用。

  18. Sensitivity Analysis for DHRS Heat Exchanger Performance Tests of PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jonggan; Eoh, Jaehyuk; Kim, Dehee; Lee, Taeho; Jeong, Jiyoung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The STELLA-1 facility has been constructed and separate effect tests of heat exchangers for DHRS are going to be conducted. Two kinds of heat exchangers including DHX (shell-and-tube sodium-to-sodium heat exchanger) and AHX (helical-tube sodium-to-air heat exchanger) will be tested for design codes V and V. Main test points are a design point and a plant normal operation point of each heat exchanger. Additionally, some plant transient conditions are taken into account for establishing a test condition set. To choose the plant transient test conditions, a sensitivity analysis has been conducted using the design codes for each heat exchanger. The sensitivity of the PGSFR DHRS heat exchanger tests (the DHX and AHX in the STELLA-1 facility) has been analyzed through a parametric study using the design codes SHXSA and AHXSA at the design point and the plant normal operation point. The DHX heat transfer performance was sensitive to the change in the inlet temperature of the shell-side and the AHX heat transfer performance was sensitive to the change in the inlet temperature of the tube side. The results of this work will contribute to an improvement of the test matrix for the separate effect test of each heat exchanger.

  19. A Numerical Algorithm and a Graphical Method to Size a Heat Exchanger

    DEFF Research Database (Denmark)

    Berning, Torsten

    2011-01-01

    This paper describes the development of a numerical algorithm and a graphical method that can be employed in order to determine the overall heat transfer coefficient inside heat exchangers. The method is based on an energy balance and utilizes the spreadsheet application software Microsoft Excel......TM. The application is demonstrated in an example for designing a single pass shell and tube heat exchanger that was developed in the Department of Materials Technology of the Norwegian University of Science and Technology (NTNU) where water vapor is superheated by a secondary oil cycle. This approach can be used...

  20. Online performance assessment of heat exchanger using artificial neural networks

    Directory of Open Access Journals (Sweden)

    C. Ahilan, S. Kumanan, N. Sivakumaran

    2011-09-01

    Full Text Available Heat exchanger is a device in which heat is transferred from one medium to another across a solid surface. The performance of heat exchanger deteriorates with time due to fouling on the heat transfer surface. It is necessary to assess periodically the heat exchanger performance, in order to maintain at high efficiency level. Industries follow adopted practices to monitor but it is limited to some degree. Online monitoring has an advantage to understand and improve the heat exchanger performance. In this paper, online performance monitoring system for shell and tube heat exchanger is developed using artificial neural networks (ANNs. Experiments are conducted based on full factorial design of experiments to develop a model using the parameters such as temperatures and flow rates. ANN model for overall heat transfer coefficient of a design/ clean heat exchanger system is developed using a feed forward back propagation neural network and trained. The developed model is validated and tested by comparing the results with the experimental results. This model is used to assess the performance of heat exchanger with the real/fouled system. The performance degradation is expressed using fouling factor (FF, which is derived from the overall heat transfer coefficient of design system and real system. It supports the system to improve the performance by asset utilization, energy efficient and cost reduction interms of production loss.

  1. An experimental and numerical study of a jetfire stop material and a new helical flow heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Austegard, Anders

    1997-12-31

    This thesis consists of two parts. Part 1: Experimental and numerical study of jetfire stop, and Part 2: Experimental and numerical study of a new kind of shell and tube heat exchanger with helical flow on shell side. Part 1 describes the development of the model for simulation of the temperature development through Viking jetfirestop. A simulation program is developed that calculates the temperature development through Viking jetfire stop. In the development of the model, measurements of reaction energy, pyrolysis and heat conductivity at low temperatures are made. The conductivity at higher temperatures and when pyrolysis reactions are going on is estimated experimentally and by numerical calculations. Full-scale jet fire test and small-scale xenon lamp experiments are made to test the simulation model. Part 2 contains the development of a model that simulate the fluid flow and heat transfer in a helical flow shell and tube heat exchanger. It consists of the development of a porosity model and a model for pressure drop and heat transfer as well as experiments in non-standard tube layouts. Results from the simulation program are compared with experiments on a helical flow shell and tube heat exchanger. There is a separate appendix volume. 62 refs., 152 figs., 22 tabs.

  2. Selection of Rational Heat Transfer Intensifiers in the Heat Exchanger

    Directory of Open Access Journals (Sweden)

    S. A. Burtsev

    2016-01-01

    Full Text Available The paper considers the applicability of different types of heat transfer intensifiers in the heat exchange equipment. A review of the experimental and numerical works devoted to the intensification of the dimpled surface, surfaces with pins and internally ribbed surface were presented and data on the thermal-hydraulic characteristics of these surfaces were given. We obtained variation of thermal-hydraulic efficiency criteria for 4 different objective functions and 15 options for the intensification of heat transfer. This makes it possible to evaluate the advantages of the various heat transfer intensifiers. These equations show influence of thermal and hydraulic characteristics of the heat transfer intensifiers (the values of the relative heat transfer and drag coefficients on the basic parameters of the shell-and-tube heat exchanger: the number and length of the tubes, the volume of the heat exchanger matrix, the coolant velocity in the heat exchanger matrix, coolant flow rate, power to pump coolant (or pressure drop, the amount of heat transferred, as well as the average logarithmic temperature difference. The paper gives an example to compare two promising heat transfer intensifiers in the tubes and shows that choosing the required efficiency criterion to search for optimal heat exchanger geometry is of importance. Analysis is performed to show that a dimpled surface will improve the effectiveness of the heat exchanger despite the relatively small value of the heat transfer intensification, while a significant increase in drag of other heat transfer enhancers negatively affects their thermalhydraulic efficiency. For example, when comparing the target functions of reducing the heat exchanger volume, the data suggest that application of dimpled surfaces in various fields of technology is possible. But there are also certain surfaces that can reduce the parameters of a heat exchanger. It is shown that further work development should be aimed at

  3. Preliminary issues associated with the next generation nuclear plant intermediate heat exchanger design

    Science.gov (United States)

    Natesan, K.; Moisseytsev, A.; Majumdar, S.

    2009-07-01

    The Next Generation Nuclear Plant, with emphasis on production of both electricity and hydrogen, involves helium as the coolant and a closed-cycle gas turbine for power generation with a core outlet/gas turbine inlet temperature of 850-950 °C. In this concept, an intermediate heat exchanger is used to transfer the heat from primary helium from the core to the secondary fluid, which can be helium, a nitrogen/helium mixture, or a molten salt. This paper assesses the issues pertaining to shell-and-tube and compact heat exchangers. A detailed thermal-hydraulic analysis was performed to calculate heat transfer, temperature distribution, and pressure drop inside both printed circuit and shell-and-tube heat exchangers. The analysis included evaluation of the role of key process parameters, geometrical factors in heat exchanger designs, and material properties of structural alloys. Calculations were performed for helium-to-helium, helium-to-helium/nitrogen, and helium-to-salt heat exchangers.

  4. Direct contact liquid-liquid heat exchanger for solar heated and cooled buildings

    Science.gov (United States)

    Karaki, S.; Brothers, P.

    1980-06-01

    The technical and economic feasibility of using a direct contract liquid-liquid heat exchanger (DCLLHE) storage unit in a solar heating and cooling system is established. Experimental performance data were obtained from the CSU Solar House I using a DCLLHE for both heating and cooling functions. A simulation model for the system was developed. The model was validated using the experimental data and applied in five different climatic regions of the country for a complete year. The life-cycle cost of the system was estimated for each application. The results are compared to a conventional solar system, using a standard shell-and-tube heat exchanger. It is concluded that while there is a performance advantage with a DCLLHE system over a conventional solar system, the advantage is not sufficiently large to overcome slightly higher capital and operating costs for the DCLLHE system.

  5. A Simple Tubesheet Layout Program for Heat Exchangers

    Directory of Open Access Journals (Sweden)

    S. Murali

    2008-01-01

    Full Text Available The development of tubesheet layout program for shell and tube heat exchangers is presented in this study. Program is written in AutoLISP language, which provides standard tubesheet layout drawing as per standard codes and non standard tubsheet in AutoCAD Environment. The program computes the optimal number of tube count and lays out drawing with respecting constraints, including the shell ID, number of passes, center to center distance of tubes and tube outer diameter. Tubesheet layout drawing can be used as template for actual tubesheet. Furthermore the program is validated with open literature and shown good agreement with it. Besides the tubesheet for Heat exchangers this method can be extended to the tube counts of sheave plates and perforated plates of distillation column and Cooling Towers.

  6. Physical explosion analysis in heat exchanger network design

    Science.gov (United States)

    Pasha, M.; Zaini, D.; Shariff, A. M.

    2016-06-01

    The failure of shell and tube heat exchangers is being extensively experienced by the chemical process industries. This failure can create a loss of production for long time duration. Moreover, loss of containment through heat exchanger could potentially lead to a credible event such as fire, explosion and toxic release. There is a need to analyse the possible worst case effect originated from the loss of containment of the heat exchanger at the early design stage. Physical explosion analysis during the heat exchanger network design is presented in this work. Baker and Prugh explosion models are deployed for assessing the explosion effect. Microsoft Excel integrated with process design simulator through object linking and embedded (OLE) automation for this analysis. Aspen HYSYS V (8.0) used as a simulation platform in this work. A typical heat exchanger network of steam reforming and shift conversion process was presented as a case study. It is investigated from this analysis that overpressure generated from the physical explosion of each heat exchanger can be estimated in a more precise manner by using Prugh model. The present work could potentially assist the design engineer to identify the critical heat exchanger in the network at the preliminary design stage.

  7. An Alternative Algorithm for Optimal Design of Plate Heat Exchangers

    Directory of Open Access Journals (Sweden)

    Seyyed Morteza Javid

    2015-02-01

    Full Text Available Due to the complex geometry of plate heat exchangers and thus a large number of variables affecting the performance of the exchangers, the design of these types of exchangers is quiet difficult. However, unlike the shell and tube heat exchangers which contain available data of design procedures, the design of plate heat exchanger is a monopoly of some certain manufacturing companies that make the problem even worse. In this paper, the objective is to minimize the number of plates in plate heat exchanger; in order to achieve that, a simple and yet efficient mathematical model is introduced for determination of the pressure drop and heat capacity of a plate heat exchanger in single- and multipass state and also a program was defined for determination of optimal solution based on this simple mathematical model for given operational constraints and plate type. In the end, the optimal solution will be compared to the answer of CAS200 commercial software and also it is shown that the effect of the start and end plates and transverse distribution in optimal solution is considerable.

  8. Optimasi Desain Heat Exchanger dengan Menggunakan Metode Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Rifnaldi Veriyawan

    2014-09-01

    Full Text Available Industri proses terutama perminyakan adalah salah satu industri membutuhkan energi panas dengan jumlah kapasitas besar. Dengan berjalan perkembangan teknologi dibutuhkannya proses perpindahan panas dalam jumlah besar. Tetapi dengan besarnya penukaran panas yang diberikan maka besar pula luas permukaan. Dibutuhkannya optimasi pada desain heat exchanger terutama shell-and-tube¬. Dalam tugas akhir ini, Algoritma particle swarm optimization (PSO digunakan untuk mengoptimasikan nilai koefesien perpindahan panas keseluruhan dengan mendapatkan nilai terbaik. Perumusan fungsi tujuan nilai perpindahan panas keseluruhan (U, dan luas permukaan (A yang digunakan untuk mencari nilai fungsi objektif pada PSO. Partikel dalam PSO menyatakan sebagai posisi atau solusi dari hasil optimasi didapatnya nilai perpindahan panas maksimal dengan luas permukaan dan pressure drop dibawah data desain atau datasheet. Partikel tersebut dalam pemodelan berupa rentang nilai minimal dan maksimal dari diameter luar diantara (do dan jumlah baffle (Nb. Dari hasil optimasi pada tiga HE didapatkan nilai U dan A secara berturut-turut; HE E-1111 472 W/m2C dan 289 m2 ;pada HE E-1107 174 W/m2C dan 265 m2 ; dan HE E-1102 618 W/m2C dan 574 m2. Nilai perpindahan panas keseluruhan yang telah dioptimasi sesuai dengan fungsi objektif dapat dikatakan HE shell-and-tube mencapai titik optimal.

  9. Heat exchangers for cardioplegia systems: in vitro study of four different concepts.

    Science.gov (United States)

    Drummond, Mário; Novello, Waldyr Parorali; de Arruda, Antonio Celso Fonseca; Braile, Domingo Marcolino

    2003-05-01

    The aim of this work is the evaluation of four different heat exchangers used for myocardium during cardioplegic system in cardiac surgeries. Four types of shell and tube heat exchangers made of different exchange elements were constructed, as follows: stainless steel tubes, aluminium tubes, polypropylene hollow fiber, and bellows type. The evaluation was performed by in vitro tests of parameters such as heat transfer, pressure drop, and hemolysis tendency. The result has shown that all four systems tested were able to achieve the heat performance, and to offer low resistance to flow, and safety, as well as have low tendency to hemolysis. However, we can emphasize that the bellows type heat exchanger has a significant difference with regard to the other three types.

  10. Appendix to the thesis an experimental and numerical study of a jetfire stop material and a new helical flow heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Austegard, Anders

    1997-12-31

    This thesis consists of two parts. Part 1: Experimental and numerical study of jetfire stop, and Part 2: Experimental and numerical study of a new kind of shell and tube heat exchanger with helical flow on shell side. Part 1 describes the development of the model for simulation of the temperature development through Viking jetfirestop. A simulation program is developed that calculates the temperature development through Viking jetfirestop. In the development of the model, measurements of reaction energy, pyrolysis and heat conductivity at low temperatures are made. The conductivity at higher temperatures and when pyrolysis reactions are going on is estimated experimentally and by numerical calculations. Full-scale jet fire test and small-scale xenon lamp experiments are made to test the simulation model. Part 2 contains the development of a model that simulate the fluid flow and heat transfer in a helical flow shell and tube heat exchanger. It consists of the development of a porosity model and a model for pressure drop and heat transfer as well as experiments in non-standard tube layouts. Results from the simulation program are compared with experiments on a helical flow shell and tube heat exchanger. This is a separate appendix volume, including computer codes and simulated results. 316 figs., 11 tabs.

  11. Heat Exchanger Design Options and Tritium Transport Study for the VHTR System

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim

    2008-09-01

    This report presents the results of a study conducted to consider heat exchanger options and tritium transport in a very high temperature reactor (VHTR) system for the Next Generation Nuclear Plant Project. The heat exchanger options include types, arrangements, channel patterns in printed circuit heat exchangers (PCHE), coolant flow direction, and pipe configuration in shell-and-tube designs. Study considerations include: three types of heat exchanger designs (PCHE, shell-and-tube, and helical coil); single- and two-stage unit arrangements; counter-current and cross flow configurations; and straight pipes and U-tube designs in shell-and-tube type heat exchangers. Thermal designs and simple stress analyses were performed to estimate the heat exchanger options, and the Finite Element Method was applied for more detailed calculations, especially for PCHE designs. Results of the options study show that the PCHE design has the smallest volume and heat transfer area, resulting in the least tritium permeation and greatest cost savings. It is theoretically the most reliable mechanically, leading to a longer lifetime. The two-stage heat exchanger arrangement appears to be safer and more cost effective. The recommended separation temperature between first and second stages in a serial configuration is 800oC, at which the high temperature unit is about one-half the size of the total heat exchanger core volume. Based on simplified stress analyses, the high temperature unit will need to be replaced two or three times during the plant’s lifetime. Stress analysis results recommend the off-set channel pattern configuration for the PCHE because stress reduction was estimated at up to 50% in this configuration, resulting in a longer lifetime. The tritium transport study resulted in the development of a tritium behavior analysis code using the MATLAB Simulink code. In parallel, the THYTAN code, previously performed by Ohashi and Sherman (2007) on the Peach Bottom data, was revived

  12. 基于FLUENT的管壳式换热器数值模拟研究%Numerical Simulation Study on Shell and Tube Heat Exchangers Based on FLUENT

    Institute of Scientific and Technical Information of China (English)

    潘胜; 史金鑫

    2013-01-01

    利用GAMBIT软件,建立管壳式换热器壳程流场简化模型,进行网格划分并设定各边界;利用FLUENT软件,进行有限元计算.通过设定求解器类型、具体边界条件值以及松弛因子,对模型进行迭代计算.对壳程流体的压力场、温度场和速度场的特点进行了分析,可为管壳式换热器的设计和使用提供参考.

  13. 大型管壳式换热器数值模拟分析%Study on numerical simulation of large-scale shell and tube heat exchanger

    Institute of Scientific and Technical Information of China (English)

    揭涛; 张世程; 匡建平; 赵子通; 刘思远

    2015-01-01

    以某硫酸厂大型管壳式乙二醇换热器为分析对象,采用CFD软件FLUENT对其整体结构进行数值模拟,得出了换热器整体流场和温度场特性,分析了关键区域折流板和特征换热管的温度分布,并与实际测量值作出对比.研究结果可为换热器的设计方法和换热器的故障分析手段提供参考.

  14. 小型管壳式换热器壳侧换热CFD分析%Shell Side CFD Analysis of a Small Shell-and Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    龙隽雅; 刘刚; 甘长德

    2015-01-01

    本文运用CFD软件Fluent对小型管壳式换热器壳侧流场和温度场进行数值模拟,研究不同数量折流板(即不同折流板间距)对于换热器压降大小和传热系数的影响.对比CFD模拟结果与Bell-Delaware实验数据,结果吻合良好,证明了本数值模拟的准确性.

  15. 管壳式换热器流场数值模拟方法%A Summary of Numerical Modeling of Shell-and-Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    熊智强; 喻九阳; 熊智斌

    2006-01-01

    介绍了对管壳式换热器研究的基本方法.对数值模拟的优缺点和模拟的软件做了简要介绍,并对常用于管壳式换热器的两种方法:直接数值模拟和多孔介质模型两种类别作了明确阐述.

  16. 管壳式换热器工艺设计的新挑战%New challenges in design calculations of the shell-and-tube heat exchangers

    Institute of Scientific and Technical Information of China (English)

    刘明言; 林瑞泰; 李修伦; 黄鸿鼎

    2005-01-01

    随着计算机技术的发展,计算机辅助设计法(CAD)和基于计算流体动力学(CFD)和数值传热学的设计方法将是21世纪管壳式换热器的2种主要设计方法;同时,为了进行有效的管壳式换热器工艺设计,还需要面对目前存在的诸如多相流动及传热、最优化、传热强化、流体振动、污垢、高粘度流体、物性数据库、湍流、非线性传热、换热器中流动及传热过程的数值模拟等十大挑战性难题,这也是未来的研究方向.

  17. Studi Numerik Pengaruh Baffle Inclination Pada Alat Penukar Kalor Tipe Shell And Tube Terhadap Aliran Fluida Dan Perpindahan Panas

    Directory of Open Access Journals (Sweden)

    Rezky Fadil Arnaw

    2014-09-01

    Full Text Available Heat exchanger atau alat penukar kalor merupakan suatu peralatan yang digunakan untuk memindahkan sejumlah energi dalam bentuk panas dari satu fluida ke fluida yang lain. Perpindahan panas tersebut terjadi dari suatu fluida yang suhunya lebih tinggi ke fluida lain yang suhunya lebih rendah. Pada tugas akhir ini akan dilakukan penelitian tentang pengaruh baffle inclination terhadap aliran fluida dan perpindahan panas pada alat penukar kalor tipe shell and tube. Dalam penelitian ini akan dilakukan tiga variasi sudut baffle inclination yaitu 0º, 10° dan 20° dengan besar laju aliran massa yang divariasikan yaitu sebesar 0.5 kg/s, 1 kg/s dan 2 kg/s. Tipe baffle yang digunakan adalah single segmental baffle dengan baffle cut sebesar 36% dan menggunakan arah aliran jenis parallel. Hasil analisa simulasi menunjukkan bahwa laju aliran massa yang meningkat akan menyebabkan kenaikan pressure drop yang cukup drastis dan penurunan temperatur outlet. Alat penukar kalor dengan baffle inclination 0° memiliki nilai perpindahan panas terbaik jika dibandingkan dengan baffle inclination 10° dan 20°.

  18. Heat transfer characteristics and enhancement of shell and tube adsorbent beds%壳管式吸附床传热特性及其强化传热研究

    Institute of Scientific and Technical Information of China (English)

    陈焕新; 魏莉; 张绰; 殷明

    2012-01-01

    为了实现吸附制冷系统连续工作,在分析国内外系统循环方式的基础上,建立了多发生器系统.对吸附制冷系统的能量需求进行了计算,着重研究了吸附床的显热在总热量中所占的比例,通过外加肋片的方式减小吸附床切换过程中的过渡时间,增加系统制冷量、提高系统运行效率.理论研究结果表明:低压蒸汽作为吸附制冷系统驱动热源时,系统的制冷效率可达27%,单位质量吸附剂的制冷量为172W/kg.%To achieve continuous adsorption refrigeration, the system with multi-adsorbers was estab- lished. The energy demands of the adsorption refrigeration system and the proportion of the sensible heat of adsorption bed total heat were calculated. By adding fins outside unit tubes, the switching transition time of the adsorbent bed was shorted, and the cooling capacity and the efficiency of the system were improved. The theoretical results show that when the steam is the heat source of solid adsorption refrigeration, the system cooling efficiency is 27%, and the cooling capacity per mass ad- sorbent is 172 W/kg.

  19. Optimization of Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Ivan Catton

    2010-10-01

    The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics )pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger disign.

  20. Compact, super heat exchanger

    Science.gov (United States)

    Fortini, A.; Kazaroff, J. M.

    1980-01-01

    Heat exchanger uses porous media to enhance heat transfer through walls of cooling channels, thereby lowering wall temperature. Porous media within cooling channel increases internal surface area from which heat can be transferred to coolant. Comparison data shows wall has lower temperature and coolant has higher temperature when porous medium is used within heat exchanger. Media can be sintered powedered metal, metal fibers, woven wire layers, or any porous metal having desired permeability and porosity.

  1. Design and simulation of heat exchangers using Aspen HYSYS, and Aspen exchanger design and rating for paddy drying application

    Science.gov (United States)

    Janaun, J.; Kamin, N. H.; Wong, K. H.; Tham, H. J.; Kong, V. V.; Farajpourlar, M.

    2016-06-01

    Air heating unit is one of the most important parts in paddy drying to ensure the efficiency of a drying process. In addition, an optimized air heating unit does not only promise a good paddy quality, but also save more for the operating cost. This study determined the suitable and best specifications heating unit to heat air for paddy drying in the LAMB dryer. In this study, Aspen HYSYS v7.3 was used to obtain the minimum flow rate of hot water needed. The resulting data obtained from Aspen HYSYS v7.3 were used in Aspen Exchanger Design and Rating (EDR) to generate heat exchanger design and costs. The designs include shell and tubes and plate heat exchanger. The heat exchanger was designed in order to produce various drying temperatures of 40, 50, 60 and 70°C of air with different flow rate, 300, 2500 and 5000 LPM. The optimum condition for the heat exchanger were found to be plate heat exchanger with 0.6 mm plate thickness, 198.75 mm plate width, 554.8 mm plate length and 11 numbers of plates operating at 5000 LPM air flow rate.

  2. Nature's Heat Exchangers.

    Science.gov (United States)

    Barnes, George

    1991-01-01

    Discusses the heat-transfer systems of different animals. Systems include heat conduction into the ground, heat transferred by convection, heat exchange in lizards, fish and polar animals, the carotid rete system, electromagnetic radiation from animals and people, and plant and animal fiber optics. (MDH)

  3. Active microchannel heat exchanger

    Science.gov (United States)

    Tonkovich, Anna Lee Y [Pasco, WA; Roberts, Gary L [West Richland, WA; Call, Charles J [Pasco, WA; Wegeng, Robert S [Richland, WA; Wang, Yong [Richland, WA

    2001-01-01

    The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

  4. Technology Development of the New Efficient Heat Exchanger at Home and Aboard%国内外新型高效换热器

    Institute of Scientific and Technical Information of China (English)

    马晓驰

    2001-01-01

    Recent progress of heat exchanger at home and abroad in recent years is outlined.Methods of enhancing the heat transfer in heat exchanger about the shell and tube sides are introduced and commented.%简述了国内外近年来换热器的发展概况。介绍了管壳式换热器中管程、壳程的强化传热研究以及国内外推出的各种新型换热器的有关情况。

  5. Overall heat transfer coefficient and pressure drop in a typical tubular exchanger employing alumina nano-fluid as the tube side hot fluid

    Science.gov (United States)

    Kabeel, A. E.; Abdelgaied, Mohamed

    2016-08-01

    Nano-fluids are used to improve the heat transfer rates in heat exchangers, especially; the shell-and-tube heat exchanger that is considered one of the most important types of heat exchangers. In the present study, an experimental loop is constructed to study the thermal characteristics of the shell-and-tube heat exchanger; at different concentrations of Al2O3 nonmetallic particles (0.0, 2, 4, and 6 %). This material concentrations is by volume concentrations in pure water as a base fluid. The effects of nano-fluid concentrations on the performance of shell and tube heat exchanger have been conducted based on the overall heat transfer coefficient, the friction factor, the pressure drop in tube side, and the entropy generation rate. The experimental results show that; the highest heat transfer coefficient is obtained at a nano-fluid concentration of 4 % of the shell side. In shell side the maximum percentage increase in the overall heat transfer coefficient has reached 29.8 % for a nano-fluid concentration of 4 %, relative to the case of the base fluid (water) at the same tube side Reynolds number. However; in the tube side the maximum relative increase in pressure drop has recorded the values of 12, 28 and 48 % for a nano-material concentration of 2, 4 and 6 %, respectively, relative to the case without nano-fluid, at an approximate value of 56,000 for Reynolds number. The entropy generation reduces with increasing the nonmetallic particle volume fraction of the same flow rates. For increase the nonmetallic particle volume fraction from 0.0 to 6 % the rate of entropy generation decrease by 10 %.

  6. Selection of the air heat exchanger operating in a gas turbine air bottoming cycle

    Science.gov (United States)

    Chmielniak, Tadeusz; Czaja, Daniel; Lepszy, Sebastian

    2013-12-01

    A gas turbine air bottoming cycle consists of a gas turbine unit and the air turbine part. The air part includes a compressor, air expander and air heat exchanger. The air heat exchanger couples the gas turbine to the air cycle. Due to the low specific heat of air and of the gas turbine exhaust gases, the air heat exchanger features a considerable size. The bigger the air heat exchanger, the higher its effectiveness, which results in the improvement of the efficiency of the gas turbine air bottoming cycle. On the other hand, a device with large dimensions weighs more, which may limit its use in specific locations, such as oil platforms. The thermodynamic calculations of the air heat exchanger and a preliminary selection of the device are presented. The installation used in the calculation process is a plate heat exchanger, which is characterized by a smaller size and lower values of the pressure drop compared to the shell and tube heat exchanger. Structurally, this type of the heat exchanger is quite similar to the gas turbine regenerator. The method on which the calculation procedure may be based for real installations is also presented, which have to satisfy the economic criteria of financial profitability and cost-effectiveness apart from the thermodynamic criteria.

  7. Thermoelectric heat exchange element

    Science.gov (United States)

    Callas, James J.; Taher, Mahmoud A.

    2007-08-14

    A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

  8. Simulation of shell-tube and heat exchangers: film coefficients. Simulacion de intercambiadores de carcasa y tubos: coeficientes de pelicula

    Energy Technology Data Exchange (ETDEWEB)

    Inostraza Hoffmann, X.E.; Pares Perez, J.A.

    1993-01-01

    The heat transfer of process fluids is a main part of them and the interchanges of shell and tubes are used in these applications. This study presents coefficients calculation of film and heat losses. (Author) 3 refs.

  9. Heat exchanger design handbook

    CERN Document Server

    Thulukkanam, Kuppan

    2013-01-01

    Completely revised and updated to reflect current advances in heat exchanger technology, Heat Exchanger Design Handbook, Second Edition includes enhanced figures and thermal effectiveness charts, tables, new chapter, and additional topics--all while keeping the qualities that made the first edition a centerpiece of information for practicing engineers, research, engineers, academicians, designers, and manufacturers involved in heat exchange between two or more fluids.See What's New in the Second Edition: Updated information on pressure vessel codes, manufacturer's association standards A new c

  10. Microplate Heat Exchanger Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a microplate heat exchanger for cryogenic cooling systems used for continuous flow distributed cooling systems, large focal plane arrays, multiple cooling...

  11. Counterflow Regolith Heat Exchanger

    Science.gov (United States)

    Zubrin, Robert; Jonscher, Peter

    2013-01-01

    A problem exists in reducing the total heating power required to extract oxygen from lunar regolith. All such processes require heating a great deal of soil, and the heat energy is wasted if it cannot be recycled from processed material back into new material. The counterflow regolith heat exchanger (CoRHE) is a device that transfers heat from hot regolith to cold regolith. The CoRHE is essentially a tube-in-tube heat exchanger with internal and external augers attached to the inner rotating tube to move the regolith. Hot regolith in the outer tube is moved in one direction by a right-hand - ed auger, and the cool regolith in the inner tube is moved in the opposite direction by a left-handed auger attached to the inside of the rotating tube. In this counterflow arrangement, a large fraction of the heat from the expended regolith is transferred to the new regolith. The spent regolith leaves the heat exchanger close to the temperature of the cold new regolith, and the new regolith is pre-heated close to the initial temperature of the spent regolith. Using the CoRHE can reduce the heating requirement of a lunar ISRU system by 80%, reducing the total power consumption by a factor of two. The unique feature of this system is that it allows for counterflow heat exchange to occur between solids, instead of liquids or gases, as is commonly done. In addition, in variants of this concept, the hydrogen reduction can be made to occur within the counterflow heat exchanger itself, enabling a simplified lunar ISRU (in situ resource utilization) system with excellent energy economy and continuous nonbatch mode operation.

  12. Preliminary Evaluation of PGSFR DHR Heat Exchangers Performance Using STELLA-1 Facility

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jonggan; Eoh, Jae-Hyuk; Yeom, Sujin; Lee, Jewhan; Kim, Tae-Joon; Hwang, Inkoo; Cho, Chungho; Kim, Jong-Man; Cho, Youngil; Jung, Min-Hwan; Gam, Da-Young; Jeong, Ji-Young [Korean Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The STELLA program for PGSFR decay heat removal (DHR) performance demonstration is in progress at KAERI. As the first phase of the program, the STELLA-1 facility has been constructed and separate effect tests for heat exchangers of DHRS have been conducted. Two kinds of heat exchangers including a shell-and-tube type sodium-to-sodium heat exchanger (DHX) and a helical-tube type sodium-to-air heat exchanger (AHX) were tested for design codes V-V, e.g. SHXSA and AHXSA. In this paper, firstly, overall characteristics of the STELLA-1 facility are described briefly. Secondly, the performance tests of the DHX and AHX rely on a steady-state result of a heat transfer experiment. Thus experimental procedures to obtain the steady-state result are described and steady-state conditions for the heat exchanger performance test are clearly defined. Lastly, experimental results and calculation results obtained from the design codes are also compared as a preliminary work for the design code V-V. The PGSFR DHR heat exchangers performance was experimentally demonstrated using the STELLA-1 facility, and the experimental results and the prediction of the design code were compared as a preliminary work for the design code V-V. The experimental results of the DHX and AHX were in good agreement with the estimation of the SHXSA and AHXSA codes, respectively.

  13. 全焊板式热交换器在热电联产机组中的应用%Application of All-Welded Plate Type Heat Exchanger in Cogeneration Units

    Institute of Scientific and Technical Information of China (English)

    金正风

    2016-01-01

    The heat exchanger is the most important auxiliary engine equipment system in cogeneration units. Introduction was made to the struc-tural features of all-welded plate heat exchangers, the heat diffusion principle and its application in cogeneration units. This paper compared and ana-lyzed it with traditional shell-and-tube heat exchanger. The analysis results show that the all-welded plate heat exchanger has advantages of both new type removable heat exchanger and traditional shell-and-tube heat exchanger, possesses distinguished heat transfer property under the heat diffusion working conditions of high temperature and high pressure medium, and can replace the shell-and-tube heat exchanger sufifciently under multiple working conditions.%热交换器设备是热电联产机组中最重要的辅机设备体系,介绍了全焊板式热交换器的结构特点、传热原理及其在热电联产机组中的应用,并将其与传统管壳式热交换器进行了对比分析。分析结果表明,全焊板式热交换器兼备新型可拆板式热交换器和传统管壳式热交换器两者的优点,在高温高压介质传热工况下拥有卓越的传热性能,可在多个工况中充分替代管壳式热交换器。

  14. Heat exchanger restart evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, J.M.; Hirst, C.W.; Lentz, T.F.

    1992-02-28

    On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat exchanger 4A (HX 4A). The heat exchanger was isolated and the plant shutdown. Heat exchanger 4kA was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat exchanger 4A for metallurgical examination. Additional analysis and review of heat exchanger leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summarized herein.

  15. Shell and Tube Heat Exchanger Heat Exchanger Heat Transfer Technology Brief Introduction%管壳式换热器的换热管强化传热技术浅述

    Institute of Scientific and Technical Information of China (English)

    段亚平

    2010-01-01

    介绍了管壳式换热器的换热管强化传热技术,分析了各自的原理、优缺点及推荐的使用场合.采用节能技术的换热器不仅提高了能源的利用率,而且减少了金属材料的消耗,对化工行业提高经济效益具有重要意义.

  16. Multilinear Model of Heat Exchanger with Hammerstein Structure

    Directory of Open Access Journals (Sweden)

    Dragan Pršić

    2016-01-01

    Full Text Available The multilinear model control design approach is based on the approximation of the nonlinear model of the system by a set of linear models. The paper presents the method of creation of a bank of linear models of the two-pass shell and tube heat exchanger. The nonlinear model is assumed to have a Hammerstein structure. The set of linear models is formed by decomposition of the nonlinear steady-state characteristic by using the modified Included Angle Dividing method. Two modifications of this method are proposed. The first one refers to the addition to the algorithm for decomposition, which reduces the number of linear segments. The second one refers to determination of the threshold value. The dependence between decomposition of the nonlinear characteristic and the linear dynamics of the closed-loop system is established. The decoupling process is more formal and it can be easily implemented by using software tools. Due to its simplicity, the method is particularly suitable in complex systems, such as heat exchanger networks.

  17. Scraped surface heat exchangers.

    Science.gov (United States)

    Rao, Chetan S; Hartel, Richard W

    2006-01-01

    Scraped surface heat exchangers (SSHEs) are commonly used in the food, chemical, and pharmaceutical industries for heat transfer, crystallization, and other continuous processes. They are ideally suited for products that are viscous, sticky, that contain particulate matter, or that need some degree of crystallization. Since these characteristics describe a vast majority of processed foods, SSHEs are especially suited for pumpable food products. During operation, the product is brought in contact with a heat transfer surface that is rapidly and continuously scraped, thereby exposing the surface to the passage of untreated product. In addition to maintaining high and uniform heat exchange, the scraper blades also provide simultaneous mixing and agitation. Heat exchange for sticky and viscous foods such as heavy salad dressings, margarine, chocolate, peanut butter, fondant, ice cream, and shortenings is possible only by using SSHEs. High heat transfer coefficients are achieved because the boundary layer is continuously replaced by fresh material. Moreover, the product is in contact with the heating surface for only a few seconds and high temperature gradients can be used without the danger of causing undesirable reactions. SSHEs are versatile in the use of heat transfer medium and the various unit operations that can be carried out simultaneously. This article critically reviews the current understanding of the operations and applications of SSHEs.

  18. Microgravity condensing heat exchanger

    Science.gov (United States)

    Thomas, Christopher M. (Inventor); Ma, Yonghui (Inventor); North, Andrew (Inventor); Weislogel, Mark M. (Inventor)

    2011-01-01

    A heat exchanger having a plurality of heat exchanging aluminum fins with hydrophilic condensing surfaces which are stacked and clamped between two cold plates. The cold plates are aligned radially along a plane extending through the axis of a cylindrical duct and hold the stacked and clamped portions of the heat exchanging fins along the axis of the cylindrical duct. The fins extend outwardly from the clamped portions along approximately radial planes. The spacing between fins is symmetric about the cold plates, and are somewhat more closely spaced as the angle they make with the cold plates approaches 90.degree.. Passageways extend through the fins between vertex spaces which provide capillary storage and communicate with passageways formed in the stacked and clamped portions of the fins, which communicate with water drains connected to a pump externally to the duct. Water with no entrained air is drawn from the capillary spaces.

  19. Heat exchange apparatus

    Science.gov (United States)

    Degtiarenko, Pavel V.

    2003-08-12

    A heat exchange apparatus comprising a coolant conduit or heat sink having attached to its surface a first radial array of spaced-apart parallel plate fins or needles and a second radial array of spaced-apart parallel plate fins or needles thermally coupled to a body to be cooled and meshed with, but not contacting the first radial array of spaced-apart parallel plate fins or needles.

  20. Direct contact liquid-liquid heat exchanger for solar heated and cooled buildings. Final report, January 1, 1979-May 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Karaki, S.; Brothers, P.

    1980-06-01

    The technical and economic feasibility of using a direct contact liquid-liquid heat exchanger (DCLLHE) storage unit in a solar heating and cooling system is established. Experimental performance data were obtained from the CSU Solar House I using a DCLLHE for both heating and cooling functions. A simulation model for the system was developed. The model was validated using the experimental data and applied in five different climatic regions of the country for a complete year. The life-cycle cost of the system was estimated for each application. The results are compared to a conventional solar system, using a standard shell-and-tube heat exchanger. It is concluded that while thare is a performance advantage with a DCLLHE system over a conventional solar system, the advantage is not sufficiently large to overcome slightly higher capital and operating costs for the DCLLHE system.

  1. Robust multi-objective optimization of state feedback controllers for heat exchanger system with probabilistic uncertainty

    Science.gov (United States)

    Lotfi, Babak; Wang, Qiuwang

    2013-07-01

    The performance of thermal control systems has, in recent years, improved in numerous ways due to developments in control theory and information technology. The shell-and-tube heat exchanger (STHX) is a medium where heat transfer process occurred. The accuracy of the heat exchanger depends on the performance of both elements. Therefore, both components need to be controlled in order to achieve a substantial result in the process. For this purpose, the actual dynamics of both shell and tube of the heat exchanger is crucial. In this paper, optimal reliability-based multi-objective Pareto design of robust state feedback controllers for a STHX having parameters with probabilistic uncertainties. Accordingly, the probabilities of failure of those objective functions are also considered in the reliability-based design optimization (RBDO) approach. A new multi-objective uniform-diversity genetic algorithm (MUGA) is presented and used for Pareto optimum design of linear state feedback controllers for STHX problem. In this way, Pareto front of optimum controllers is first obtained for the nominal deterministic STHX using the conflicting objective functions in time domain. Such Pareto front is then obtained for STHX having probabilistic uncertainties in its parameters using the statistical moments of those objective functions through a Hammersley Sequence Sampling (HSS) approach. It is shown that multi-objective reliability-based Pareto optimization of the robust state feedback controllers using MUGA includes those that may be obtained by various crisp threshold values of probability of failures and, thus, remove the difficulty of selecting suitable crisp values. Besides, the multi-objective Pareto optimization of such robust feedback controllers using MUGA unveils some very important and informative trade-offs among those objective functions. Consequently, some optimum robust state feedback controllers can be compromisingly chosen from the Pareto frontiers.

  2. Cleaning and Heat Transfer in Heat Exchanger with Circulating Fluidized Beds

    Science.gov (United States)

    Kang, Ho Keun; Ahn, Soo Whan; Choi, Jong Woong; Lee, Byung Chang

    2010-06-01

    Fluidized bed type heat exchangers are known to increase the heat transfer and prevent the fouling. For proper design of circulating fluidized bed heat exchanger it is important to know the effect of design and operating parameters on the bed to the wall heat transfer coefficient. The present experimental and numerical study was conducted to investigate the effects of circulating solid particles on the characteristics of fluid flow, heat transfer and cleaning effect in the fluidized bed vertical shell and tube type heat exchanger with counterflow, at which a variety of solid particles such as glass (3 mmF), aluminum (2˜3 mmF), steel (2˜2.5 mmF), copper (2.5 mmF) and sand (2˜4 mmF) were used in the fluidized bed with a smooth tube. Seven different solid particles have the same volume, and the effects of various parameters such as water flow rates, particle diameter, materials and geometry were investigated. The present experimental and numerical results showed that the flow velocity range for collision of particles to the tube wall was higher with heavier density solid particles, and the increase in heat transfer was in the order of sand, copper, steel, aluminum, and glass. This behaviour might be attributed to the parameters such as surface roughness or particle heat capacity. Fouling examination using 25,500 ppm of ferric oxide (Fe2O3) revealed that the tube inside wall is cleaned by a mild and continuous scouring action of fluidized solid particles. The fluidized solid particles not only keep the surface clean, but they also break up the boundary layer improving the heat transfer coefficient even at low fluid velocities.

  3. Small particle heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, A.J.

    1978-06-01

    A dispersion of small absorbing particles forms an ideal system to collect radiant energy, transform it to heat, and efficiently transfer the heat to a surrounding fluid. If the heated fluid is a pressurized gas, it can be passed through an expansion turbine to create useful mechanical energy. The most obvious application of this technique is its use in a solar collection system. In this case, the incoming sunlight is used to heat a compressed gas in an engine utilizing a Brayton cycle. The solar collection system may utilize high concentration as provided by a central receiver or parabolic dish, medium concentration from a linear collector, or possibly no concentration using a flat plate collector, if precautions were taken to reduce the heat losses. The same concept may be applied generally to non-solar heat exchangers. These may be of the type used to heat a gas from a combustion source, or in general as a gas to gas heat exchanger. The latter application may be limited to rather high temperature. Each of the above applications is discussed. First, a description of the concept is applied to a solar central-tower system. The general principles are described, including the optical and physical characteristics of the particles, the confinement of the gas-particle mixture, and the system considerations; the latter include the amount and type of particles, the receiver efficiency and the generation of the particles. The same considerations are reviewed for applications to linear trough and flat plate receivers. Finally, the use of small particles in non-solar heat exchangers is considered.

  4. Microtube strip heat exchanger

    Science.gov (United States)

    Doty, F. D.

    1991-04-01

    During the last quarter, Doty Scientific, Inc. (DSI) continued to make progress on the microtube strip (MTS) heat exchangers. The team has begun a heat exchanger stress analysis; however, they have been concentrating the bulk of their analytical energies on a computational fluid dynmaics (CFD) model to determine the location and magnitude of shell-side flow maldistribution which decreases heat exchanger effectiveness. DSI received 120 fineblanked tubestrips from Southern Fineblanking (SFB) for manufacturing process development. Both SFB and NIST provided inspection reports of the tubestrips. DSI completed the tooling required to encapsulate a tube array and press tubestrips on the array. Pressing the tubestrips on tube arrays showed design deficiencies both in the tubestrip design and the tooling design. DSI has a number of revisions in process to correct these deficiencies. The research effort has identified a more economical fusible alloy for encapsulating the tube array, and determined the parameters required to successfully encapsulate the tube array with the new alloy. A more compact MTS heat exchanger bank was designed.

  5. Study of heat transfer and pressure drop characteristics of air heat exchanger using PCM for free cooling applications

    Directory of Open Access Journals (Sweden)

    Kalaiselvam Sivakumar

    2016-01-01

    Full Text Available Free cooling is the process of storing the cool energy available in the night ambient air and using it during the day. The heat exchanger used in this work is a modular type which is similar to the shell and tube heat exchanger. The shell side is filled with Phase Change Materials (PCM and air flow is through the tubes in the module. The modules of the heat exchanger are arranged one over other with air spacers in between each module. The air space provided in between the module in-creases the retention time of the air for better heat transfer. Transient Computational Fluid Dynamics modeling is carried out for single air passage in a modular heat exchanger. It shows that the PCM phase transition time in the module in which different shape of fins is adopted. The module with rectangular fins has 17.2 % reduction in solidification compared with the plain module. Then steady state numerical analysis is accomplished to the whole module having the fin of high heat transfer, so that pressure drop, flow and thermal characteristics across the module and the air spacers are deter-mined for various air inlet velocities of 0.4 to 1.6 m/s. To validate the computational results, experiments are carried out and the agreement was found to be good.

  6. ASME code considerations for the compact heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Nestell, James [MPR Associates Inc., Alexandria, VA (United States); Sham, Sam [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-31

    robustness. Classic shell and tube designs will be large and costly, and may only be appropriate in steam generator service in the SHX where boiling inside the tubes occurs. For other energy conversion systems, all of these features can be met in a compact heat exchanger design. This report will examine some of the ASME Code issues that will need to be addressed to allow use of a Code-qualified compact heat exchanger in IHX or SHX nuclear service. Most effort will focus on the IHX, since the safety-related (Class A) design rules are more extensive than those for important-to-safety (Class B) or commercial rules that are relevant to the SHX.

  7. Process heat transfer principles, applications and rules of thumb

    CERN Document Server

    Serth, Robert W

    2014-01-01

    Process Heat Transfer is a reference on the design and implementation of industrial heat exchangers. It provides the background needed to understand and master the commercial software packages used by professional engineers in the design and analysis of heat exchangers. This book focuses on types of heat exchangers most widely used by industry: shell-and-tube exchangers (including condensers, reboilers and vaporizers), air-cooled heat exchangers and double-pipe (hairpin) exchangers. It provides a substantial introduction to the design of heat exchanger networks using pinch technology, the mos

  8. Bifunctional thermoelectric tube made of tilted multilayer material as an alternative to standard heat exchangers.

    Science.gov (United States)

    Takahashi, Kouhei; Kanno, Tsutomu; Sakai, Akihiro; Tamaki, Hiromasa; Kusada, Hideo; Yamada, Yuka

    2013-01-01

    Enormously large amount of heat produced by human activities is now mostly wasted into the environment without use. To realize a sustainable society, it is important to develop practical solutions for waste heat recovery. Here, we demonstrate that a tubular thermoelectric device made of tilted multilayer of Bi(0.5)Sb(1.5)Te3/Ni provides a promising solution. The Bi(0.5)Sb(1.5)Te3/Ni tube allows tightly sealed fluid flow inside itself, and operates in analogy with the standard shell and tube heat exchanger. We show that it achieves perfect balance between efficient heat exchange and high-power generation with a heat transfer coefficient of 4.0 kW/m(2)K and a volume power density of 10 kW/m(3) using low-grade heat sources below 100°C. The Bi(0.5)Sb(1.5)Te3/Ni tube thus serves as a power generator and a heat exchanger within a single unit, which is advantageous for developing new cogeneration systems in factories, vessels, and automobiles where cooling of excess heat is routinely carried out.

  9. A computer program for designing fin-and-tube heat exchanger for EGR cooler application

    Science.gov (United States)

    Syaiful, Marwan, M. A.; Tandian, N. P.; Bae, M.

    2016-03-01

    EGR (exhaust gas recirculation) cooler is a kind of heat exchanger that is used to cool exhaust gas recirculation prior to be mixed with fresh air in an intake manifold of vehicle in order to obtain good reduction of NOxemissions. A fin-and-tube heat exchanger is more preferred as an EGR cooler than a shell-and-tube heat exchanger in this study due to its compactness. Manually designing many configurations of fin-and-tube heat exchanger for EGR cooler application consumes a lot of time and is high cost. Therefore, a computer aided design process of EGR cooler is required to overcome this problem. The EGR cooler design process was started by arranging the sequences of calculation algorithm in a computer program. A cooling media for this EGR cooler is air. The design is based on the effectiveness-number transfer unit (NTU) method. The EGR cooler design gives the geometry, heat transfer surface area, heat transfer coefficient and pressure drop of the EGR cooler. Comparison of the EGR cooler Nusselt number obtained in this study and that reported in literature shows less than 6.2% discrepancy.

  10. Implementation of a Modular Hands-on Learning Pedagogy: Student Attitudes in a Fluid Mechanics and Heat Transfer Course

    Science.gov (United States)

    Burgher, J. K.; Finkel, D.; Adesope, O. O.; Van Wie, B. J.

    2015-01-01

    This study used a within-subjects experimental design to compare the effects of learning with lecture and hands-on desktop learning modules (DLMs) in a fluid mechanics and heat transfer class. The hands-on DLM implementation included the use of worksheets and one of two heat exchangers: an evaporative cooling device and a shell and tube heat…

  11. Liquid/liquid heat exchanger

    Science.gov (United States)

    Miller, C. G.

    1980-01-01

    Conceptual design for heat exchanger, utilizing two immiscible liquids with dissimilar specific gravities in direct contact, is more efficient mechanism of heat transfer than conventional heat exchangers with walls or membranes. Concept could be adapted for collection of heat from solar or geothermal sources.

  12. Fault-Tolerant Heat Exchanger

    Science.gov (United States)

    Izenson, Michael G.; Crowley, Christopher J.

    2005-01-01

    A compact, lightweight heat exchanger has been designed to be fault-tolerant in the sense that a single-point leak would not cause mixing of heat-transfer fluids. This particular heat exchanger is intended to be part of the temperature-regulation system for habitable modules of the International Space Station and to function with water and ammonia as the heat-transfer fluids. The basic fault-tolerant design is adaptable to other heat-transfer fluids and heat exchangers for applications in which mixing of heat-transfer fluids would pose toxic, explosive, or other hazards: Examples could include fuel/air heat exchangers for thermal management on aircraft, process heat exchangers in the cryogenic industry, and heat exchangers used in chemical processing. The reason this heat exchanger can tolerate a single-point leak is that the heat-transfer fluids are everywhere separated by a vented volume and at least two seals. The combination of fault tolerance, compactness, and light weight is implemented in a unique heat-exchanger core configuration: Each fluid passage is entirely surrounded by a vented region bridged by solid structures through which heat is conducted between the fluids. Precise, proprietary fabrication techniques make it possible to manufacture the vented regions and heat-conducting structures with very small dimensions to obtain a very large coefficient of heat transfer between the two fluids. A large heat-transfer coefficient favors compact design by making it possible to use a relatively small core for a given heat-transfer rate. Calculations and experiments have shown that in most respects, the fault-tolerant heat exchanger can be expected to equal or exceed the performance of the non-fault-tolerant heat exchanger that it is intended to supplant (see table). The only significant disadvantages are a slight weight penalty and a small decrease in the mass-specific heat transfer.

  13. Counterflow Regolith Heat Exchanger Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The counterflow regolith heat exchanger (CoRHE) is a device that transfers heat from hot regolith to cold regolith. The CoRHE is essentially a tube-in-tube heat...

  14. 管壳式换热器的失效、破坏后成因与控制%Failure, Failure Causes and Control of Tube and Hell Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    蒋连胜

    2016-01-01

    Shell and tube heat exchangers are widely used in high temperature and high pressure , high heat transfer coefficient , low production cost , and so on.But its structure is more complex , the use of working conditions also has the characteristics of diversity , so it will produce a variety of failure mode .The connection way and the application scope between the heat exchange tube and a tube plate was introduced in detail , the failure and destruction causes of the tube shell type heat exchanger, working medium, materials, structure of equipment, equipment operation, fluid loading, scaling and other factors on the effect of shell and tube heat exchanger failure , damage were analyzed.And the methods of preventing and controlling the failure of shell and tube heat exchanger were summarized .%管壳式换热器因耐高温高压、传热系数高、生产成本低等特点应用较为广泛。但其结构比较复杂,使用工况也具有多元化的特点,因此会产生多种失效形式。本文详细介绍了换热管和管板之间的连接方式及应用范围,分析了管壳式换热器受到失效、破坏后的成因和工作介质、材料、设备结构、设备操作、流体载荷、结垢等因素对管壳式换热器失效、破坏的影响。并总结出预防、控制管壳式换热器失效及破坏的方法。

  15. "Bottle-Brush" Heat Exchanger

    Science.gov (United States)

    Tward, E.; Gatewood, J. R.

    1982-01-01

    Heat exchanger consists of a metal tube with wires extending inward from wall. Conduction of heat along wires improves heat transfer to gas or other filling. Fluid is heated throughout the cross section of tube. Suggested applications are refrigerators, heat engines, thermal instrumentation, and heat switches.

  16. Shell-side distribution and the influence of inlet conditions in a model of a disc-and-doughnut heat exchanger

    Science.gov (United States)

    Founti, M. A.; Vardis, C.; Whitelaw, J. H.

    1985-09-01

    Measurements of wall pressure and of three orthogonal velocity components with their corresponding fluctuations are reported for two systems of alternating and equi-spaced doughnut and disc baffles axisymmetrically located in a water turbulent pipe flow, simulating the isothermal shell-side flow in shell and tube heat exchangers. The influence of inlet Reynolds number and of asymmetric inlet flow conditions was studied for two geometries. The velocity field was dominated by the pressure gradient and the flow around each individual baffle was influenced by the relative position of its neighbouring baffles.

  17. Cryogenic regenerative heat exchangers

    CERN Document Server

    Ackermann, Robert A

    1997-01-01

    An in-depth survey of regenerative heat exchangers, this book chronicles the development and recent commercialization of regenerative devices for cryogenic applications. Chapters cover historical background, concepts, practical applications, design data, and numerical solutions, providing the latest information for engineers to develop advanced cryogenic machines. The discussions include insights into the operation of a regenerator; descriptions of the cyclic and fluid temperature distributions in a regenerator; data for various matrix geometries and materials, including coarse and fine bronze, stainless steel-woven wire mesh screens, and lead spheres; and unique operating features of cryocoolers that produce deviations from ideal regenerator theory.

  18. Hybrid Heat Exchangers

    Science.gov (United States)

    Tu, Jianping Gene; Shih, Wei

    2010-01-01

    A hybrid light-weight heat exchanger concept has been developed that uses high-conductivity carbon-carbon (C-C) composites as the heat-transfer fins and uses conventional high-temperature metals, such as Inconel, nickel, and titanium as the parting sheets to meet leakage and structural requirements. In order to maximize thermal conductivity, the majority of carbon fiber is aligned in the fin direction resulting in 300 W/m.K or higher conductivity in the fin directions. As a result of this fiber orientation, the coefficient of thermal expansion (CTE) of the C-C composite in both non-fiber directions matches well with the CTE of various high-temperature metal alloys. This allows the joining of fins and parting sheets by using high-temperature braze alloys.

  19. The effect of flexible tube vibration on pressure drop and heat transfer in heat exchangers considering viscous dissipation effects

    Science.gov (United States)

    Shokouhmand, H.; Sangtarash, F.

    2008-04-01

    The pressure drop and heat transfer coefficient in tube bundle of shell and tube heat exchangers are investigated considering viscous dissipation effects. The governing equations are solved numerically. Because of temperature-dependent viscosity the equations should be solved simultaneously. The flexible tubes vibration is modeled in a quasi-static method by taking the first tube of the row to be in 20 asymmetric positions with respect to the rest of the tubes which are assumed to be fixed and time averaging the steady state solutions corresponding to each one of these positions .The results show that the eccentricity of the first tube increases pressure drop and heat transfer coefficients significantly comparing to the case of rigid tube bundles, symmetrically placed. In addition, these vibrations not only compensate the effect of viscous dissipations on heat transfer coefficient but also increase heat transfer coefficient. The constant viscosity results obtained from our numerical method have a good agreement with the available experimental data of constant viscosity for flexible tube heat exchangers.

  20. Heat exchangers for waste heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rabghi, O.M.; Akyurt, M.; Najjar, Y.S.H.; Alp, T. (King Abdulaziz Univ., Jeddah (Saudi Arabia). College of Engineering)

    1993-01-01

    A survey is made of the equipment used for heat recovery and utilization. Types and merits of commonly employed heat exchangers are presented, and criteria for selecting heat exchangers are summarized. Applications for waste heat recovery are emphasized. It is concluded that careful selection and operation of such equipment would be expected to result in energy savings as well as problem-free operation. (author)

  1. Next Generation Microchannel Heat Exchangers

    CERN Document Server

    Ohadi, Michael; Dessiatoun, Serguei; Cetegen, Edvin

    2013-01-01

    In Next Generation Microchannel Heat Exchangers, the authors’ focus on the new generation highly efficient heat exchangers and presentation of novel data and technical expertise not available in the open literature.  Next generation micro channels offer record high heat transfer coefficients with pressure drops much less than conventional micro channel heat exchangers. These inherent features promise fast penetration into many mew markets, including high heat flux cooling of electronics, waste heat recovery and energy efficiency enhancement applications, alternative energy systems, as well as applications in mass exchangers and chemical reactor systems. The combination of up to the minute research findings and technical know-how make this book very timely as the search for high performance heat and mass exchangers that can cut costs in materials consumption intensifies.

  2. Preliminary issues associated with the next generation nuclear plant intermediate heat exchanger design.

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Moisseytsev, A.; Majumdar, S.; Shankar, P. S.; Nuclear Engineering Division

    2007-04-05

    The Next Generation Nuclear Plant (NGNP), which is an advanced high temperature gas reactor (HTGR) concept with emphasis on production of both electricity and hydrogen, involves helium as the coolant and a closed-cycle gas turbine for power generation with a core outlet/gas turbine inlet temperature of 900-1000 C. In the indirect cycle system, an intermediate heat exchanger is used to transfer the heat from primary helium from the core to the secondary fluid, which can be helium, nitrogen/helium mixture, or a molten salt. The system concept for the vary high temperature reactor (VHTR) can be a reactor based on the prismatic block of the GT-MHR developed by a consortium led by General Atomics in the U.S. or based on the PBMR design developed by ESKOM of South Africa and British Nuclear Fuels of U.K. This report has made a preliminary assessment on the issues pertaining to the intermediate heat exchanger (IHX) for the NGNP. Two IHX designs namely, shell and tube and compact heat exchangers were considered in the assessment. Printed circuit heat exchanger, among various compact heat exchanger (HX) designs, was selected for the analysis. Irrespective of the design, the material considerations for the construction of the HX are essentially similar, except may be in the fabrication of the units. As a result, we have reviewed in detail the available information on material property data relevant for the construction of HX and made a preliminary assessment of several relevant factors to make a judicious selection of the material for the IHX. The assessment included four primary candidate alloys namely, Alloy 617 (UNS N06617), Alloy 230 (UNS N06230), Alloy 800H (UNS N08810), and Alloy X (UNS N06002) for the IHX. Some of the factors addressed in this report are the tensile, creep, fatigue, creep fatigue, toughness properties for the candidate alloys, thermal aging effects on the mechanical properties, American Society of Mechanical Engineers (ASME) Code compliance

  3. Interfacing heat exchanger network synthesis and detailed heat exchanger design

    Energy Technology Data Exchange (ETDEWEB)

    Polley, G.T.; Panjeh Shahi, M.H. (Manchester Univ. (United Kingdom). Inst. of Science and Technology)

    1991-11-01

    Current heat exchanger network synthesis targeting and design procedures involve the use of assumed stream heat transfer coefficients. However, during detailed heat exchanger design, allowable pressure drops are often the most critical factors. The result can be big differences between the exchanger sizes and costs anticipated by the network designer and those realised by the exchanger designer. This in turn prejudices any optimisation attempted at the network design stage. In this paper it is shown how allowable pressure drop can be used as a basis of network design and consistency between expectation and realisation achieved. (author).

  4. Multidimensional Thermal-Hydraulic Analysis for Decay Heat Exchanger of PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jonggan; Yoon, Jung; Kim, Dehee; Lee, Tae-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The decay heat exchanger (DHX) of PGSFR is a shell-and-tube type counter-current flow sodium heat exchanger, and each unit is designed for the rated thermal power of 1.0 MWt, which is corresponding to the nominal design capacity of a single passive decay heat removal system (PDHRS) and active decay heat removal system (ADHRS) loops. The DHX unit is fully immersed in the cold sodium pool region and removes the system heat load sufficiently and reliably during the temperature transient. In this work, a multidimensional thermal-hydraulic analysis for the DHX was carried out numerically and the numerical results were compared with the calculated results of the 1-D DHX design code to verify the reliability of the design code. In addition, an influence of the cold pool sodium which flows into the shell-side of the DHX through the shell outlet was evaluated. The SHXSA code was conservative in calculating the pressure drop of the shell-side which is our major concern in designing the natural circulation of the decay heat removal system. It was revealed that the buffer region is needed to reduce the thermal stress in the lower tubesheet by the inflow of the cold pool sodium.

  5. Heat exchanger leakage problem location

    Directory of Open Access Journals (Sweden)

    Jícha Miroslav

    2012-04-01

    Full Text Available Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  6. Heat exchanger leakage problem location

    Science.gov (United States)

    Hejčík, Jiří; Jícha, Miroslav

    2012-04-01

    Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  7. Numerical Simulation Analysis on the Properties of PVDF Heat Exchanger Based on Fluent%基于Fluent数值模拟对PVDF换热器性能的分析

    Institute of Scientific and Technical Information of China (English)

    魏晨晨; 孙金栋; 赵国春

    2016-01-01

    Physical model of shell-and-tube heat exchanger for PVDF has been established, the flow state for shell side fluid of heat exchanger was studied by numerical simulation through Fluent flow simulation software, the effect of heat-exchange and the change of the shell side pressure drop were analyzed, with interlaced form, orderly form and different tube spacing, get the structure design parameters of shell-and-tube heat exchanger for PVDF which is economic and reasonable, and the heat transfer efficiency is high relatively.%建立了聚偏氟乙烯(PVDF)管壳式换热器的物理模型,利用Fluent流场模拟软件对换热器壳程流体的流动状态进行了数值模拟,分析了叉排和顺排管束下、不同管间距情况下对换热的影响以及壳程压降的变化,得到了换热效率最佳且经济合理的PVDF管壳式换热器的结构设计参数。

  8. Experimental and theoretical analysis of the local condensation heat transfer in a plate heat exchanger

    Science.gov (United States)

    Grabenstein, V.; Kabelac, S.

    2012-11-01

    Plate heat exchanger (PHE) are today widely used in industrial heat transfer applications due to their good thermal performance, modest space requirement, easy accessibility to all areas and their lower capital and operating costs as compared to shell-and-tube heat exchangers. Although authoritative models for the design of PHE used as condensers are missing, the number of applications where a PHE is operating as a condenser increases. On the way to a reliable model based on physical approaches for the prediction of heat transfer and pressure drop during the condensation process inside a PHE, the flow and heat interactions as well as their dependence on the geometrical parameters of the corrugated plates and the operating conditions must be studied in detail. In this work the stepwise procedure for the fundamental construction of such a model is described. An experimental setup was built to analyze the characteristics of the two-phase-flow in PHE. A single gap, consisting of two transparent corrugated plates, was tested with a two-phase flow of air/water and also with boiling refrigerant R365mfc. Flow pattern maps were constructed for plates with corrugation angles of 27 and 63 degrees relative to the direction of flow. Investigations of the local heat transfer coefficients and the pressure drop were done with the same plates. The measurement of the local heat transfer coefficients was carried out by the use of the "Temperature Oscillation InfraRed Thermography" (TOIRT) method. Based on these results three main flow patterns are defined: film flow, bubbly flow and slug flow. For each of the three flow patterns an own model for the heat transfer and pressure drop mechanism are developed and the heat transfer coefficient and the friction factor is calculated with different equations depending on the actual steam quality, mass flow and geometrical parameters by means of a flow pattern map. The theory of the flow pattern based prediction models is proved with own

  9. High Temperature Heat Exchanger Project

    Energy Technology Data Exchange (ETDEWEB)

    Anthony E. Hechanova, Ph.D.

    2008-09-30

    The UNLV Research Foundation assembled a research consortium for high temperature heat exchanger design and materials compatibility and performance comprised of university and private industry partners under the auspices of the US DOE-NE Nuclear Hydrogen Initiative in October 2003. The objectives of the consortium were to conduct investigations of candidate materials for high temperature heat exchanger componets in hydrogen production processes and design and perform prototypical testing of heat exchangers. The initial research of the consortium focused on the intermediate heat exchanger (located between the nuclear reactor and hydrogen production plan) and the components for the hydrogen iodine decomposition process and sulfuric acid decomposition process. These heat exchanger components were deemed the most challenging from a materials performance and compatibility perspective

  10. WASTE HEAT RECOVERY FROM BOILER OF LARGE-SCALE TEXTILE INDUSTRY

    OpenAIRE

    Prateep Pattanapunt; Kanokorn Hussaro; Tika Bunnakand; Sombat Teekasap

    2013-01-01

    Many industrial heating processes generate waste energy in textile industry; especially exhaust gas from the boiler at the same time reducing global warming. Therefore, this article will present a study the way to recovery heat waste from boiler exhaust gas by mean of shell and tube heat exchanger. Exhaust gas from boiler dyeing process, which carries a large amount of heat, energy consumptions could be decrease by using of waste-heat recovery systems. In this study, using ANASYS simulation p...

  11. Review of Current Experience on Intermediate Heat Exchanger (IHX) and A Recommended Code Approach

    Energy Technology Data Exchange (ETDEWEB)

    Duane Spencer; Kevin McCoy

    2010-02-02

    The purpose of the ASME/DOE Gen IV Task 7 Part I is to review the current experience on various high temperature reactor intermediate heat exchanger (IHX) concepts. There are several different IHX concepts that could be envisioned for HTR/VHTR applications in a range of temperature from 850C to 950C. The concepts that will be primarily discussed herein are: (1) Tubular Helical Coil Heat Exchanger (THCHE); (2) Plate-Stamped Heat Exchanger (PSHE); (3) Plate-Fin Heat Exchanger (PFHE); and (4) Plate-Machined Heat Exchanger (PMHE). The primary coolant of the NGNP is potentially subject to radioactive contamination by the core as well as contamination from the secondary loop fluid. To isolate the radioactivity to minimize radiation doses to personnel, and protect the primary circuit from contamination, intermediate heat exchangers (IHXs) have been proposed as a means for separating the primary circuit of the NGNP (Next Generation Nuclear Plant) or other process heat application from the remainder of the plant. This task will first review the different concepts of IHX that could be envisioned for HTR/VHTR applications in a range of temperature from 850 to 950 C. This will cover shell-and-tube and compact designs (including the platefin concept). The review will then discuss the maturity of the concepts in terms of design, fabricability and component testing (or feedback from experience when applicable). Particular attention will be paid to the feasibility of developing the IHX concepts for the NGNP with operation expected in 2018-2021. This report will also discuss material candidates for IHX applications and will discuss specific issues that will have to be addressed in the context of the HTR design (thermal aging, corrosion, creep, creep-fatigue, etc). Particular attention will be paid to specific issues associated with operation at the upper end of the creep regime.

  12. The Simulation Study of Boiling Heat Transfer about Shell-side of the Shell-and-tube Heat Exchanger%管壳式换热器壳侧沸腾换热模拟研究

    Institute of Scientific and Technical Information of China (English)

    程国鹏; 冯立斌; 陈鹏飞

    2015-01-01

    为了研究管壳式换热器壳侧沸腾换热流动传热特点,本论文将使用Gambit软件对管壳式换热器进行划分网格等前处理,然后通过采用标准κ-ε湍流模型、混合物多相流模型,编写相应的沸腾换热自定义函数UDF,用Fluent软件对其进行壳侧沸腾换热计算,得到两相流、速度和温度等分布图,结果证明壳侧流动在弓形板后面形成了换热死区,水蒸气产生主要集中于后部,并向上聚集,最后分析了对换热器结构、强度等的影响并提出了相应的改进办法,为管壳式换热器的设计和使用提供理论参考.

  13. 管壳式换热器壳程流体流动与换热的数值模拟%Numerical simulation of shell-side flow and heat transfer characteristics in shell-and-tube heat exchanger

    Institute of Scientific and Technical Information of China (English)

    谢洪虎; 江楠

    2009-01-01

    为了研究纵向多螺旋流管壳式换热器壳程流体湍流流动与换热的工作机理,文中利用FLUENT软件,在壳程流体流速设定值不断改变的情况下,对纵向多螺旋流管壳式换热器壳程湍流流动与换热进行了三维数值模拟.得到了多螺旋流管壳式换热器在不同的壳程流体流速下的温度场、速度场、质点迹线图、壳程传热膜系数分布图等.根据模拟得到的结果,从多个方面对纵向多螺旋流管壳式换热器壳程湍流流动与强化传热进行了探讨.模拟结果与实验结果进行了比较,二者误差约在±11%以内,吻合良好.

  14. 管壳式换热器换热性能的数值模拟研究%Numerical Simulation on Heat Transfer Performance of Shell- and- tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    张东生; 杜扬; 陈思维

    2006-01-01

    在水的雷诺数Re从1900~25000范围变化的情况下,选择换热效果比较好的Φ25/Φ19波纹管,并对其换热性能进行了数值模拟与实验研究.结果显示波纹管的换热系数是直管的1.1~1.8倍,且随着雷诺数的增加,倍数值逐渐减小;波纹管的压降损失是直管的2~3倍.

  15. 管壳式换热器壳侧在强化传热方面的进展%The Developments on Heat Transfer Enhancement in the Shellside of Shell-and-tube Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    陈姝; 高学农; 徐娓; 王端阳

    2006-01-01

    本文从有功技术和无功技术两个方面讨论了管壳式换热器在壳侧强化传热方面所取得的一些进展及应用范围,并简介了CFD技术同管壳式换热器结合研究的情况,提出将几种强化技术和计算机辅助设计手段结合起来是将来换热器的发展方向.

  16. BVH all-welded plate type heat exchanger in the application of the cogeneration unit%BVH型全焊板式热交换器在热电联产机组中的应用

    Institute of Scientific and Technical Information of China (English)

    吴剑

    2014-01-01

    本文介绍了BVH型全焊板式热交换器的特点及其在热电联产机组中的应用。将其与传统管壳式热交换器进行对比分析。结果表明,BVH型全焊板式热交换器是一种新型结构紧凑高效的热交换器,可在多个工况中替代管壳式热交换器,在热电联产机组中有着广泛的应用优势和市场。%This paper introduces the characteristic of BVH all-welded plate type heat exchanger and its application in cogeneration units. Comparison and analyses of the shell-and-tube exchanger. The results show that the BVH all-welded plate type heat exchanger is a new type compact structure and high efficiency heat exchanger, it can replace the shell-and-tube exchanger, and it will be widely used in the cogeneration unitfor the distinct advantages.

  17. Simulations of thermal-hydraulic processes in heat exchangers- station of the cogeneration power plant

    Energy Technology Data Exchange (ETDEWEB)

    Studovic, M.; Stevanovic, V.; Ilic, M.; Nedeljkovic, S. [Faculty of Mechanical Engineering of Belgrade (Croatia)

    1995-12-31

    Design of the long district heating system to Belgrade (base load 580 MJ/s) from Thermal Power Station `Nikola Tesla A`, 30 km southwest from the present gas/oil burning boilers in New Belgrade, is being conducted. The mathematical model and computer code named TRP are developed for the prediction of the design basis parameters of heat exchangers station, as well as for selection of protection devices and formulation of operating procedures. Numerical simulations of heat exchangers station are performed for various transient conditions: up-set and abnormal. Physical model of multi-pass, shell and tube heat exchanger in the station represented is by unique steam volume, and with space discretised nodes both for water volume and tube walls. Heat transfer regimes on steam and water side, as well as hydraulic calculation were performed in accordance with TEMA standards for transient conditions on both sides, and for each node on water side. Mathematical model is based on balance equations: mass and energy for lumped parameters on steam side, and energy balances for tube walls and water in each node. Water mass balance is taken as boundary/initial condition or as specified control function. The physical model is proposed for (s) heat exchangers in the station and (n) water and wall volumes. Therefore, the mathematical model consists of 2ns+2, non-linear differential equations, including equations of state for water, steam and tube material, and constitutive equations for heat transfer on steam and water side, solved by the Runge-Kutt method. Five scenarios of heat exchangers station behavior have been simulated with the TRP code and obtained results are presented. (author)

  18. Milk fouling in heat exchangers.

    NARCIS (Netherlands)

    Jeurnink, Th.J.M.

    1996-01-01

    The mechanisms of fouling of heat exchangers by milk were studied. Two major fouling mechanisms were indentified during the heat treatment of milk: (i) the formation and the subsequent deposition of activated serum protein molecules as a result of the heat denaturation; (ii) the precipitation of cal

  19. Heat exchanger using graphite foam

    Science.gov (United States)

    Campagna, Michael Joseph; Callas, James John

    2012-09-25

    A heat exchanger is disclosed. The heat exchanger may have an inlet configured to receive a first fluid and an outlet configured to discharge the first fluid. The heat exchanger may further have at least one passageway configured to conduct the first fluid from the inlet to the outlet. The at least one passageway may be composed of a graphite foam and a layer of graphite material on the exterior of the graphite foam. The layer of graphite material may form at least a partial barrier between the first fluid and a second fluid external to the at least one passageway.

  20. Heat Calculation of Borehole Heat Exchangers

    Directory of Open Access Journals (Sweden)

    S. Filatov

    2013-01-01

    Full Text Available The paper considers a heat calculation method of borehole heat exchangers (BHE which can be used for designing and optimization of their design values and included in a comprehensive mathematical model of heat supply system with a heat pump based on utilization of low-grade heat from the ground.The developed method of calculation is based on the reduction of the problem general solution pertaining to heat transfer in BHE with due account of heat transfer between top-down and bottom-up flows of heat carrier to the solution for a boundary condition of one kind on the borehole wall. Used the a method of electrothermal analogy has been used for a calculation of the thermal resistance and  the required shape factors for calculation of  a borehole filler thermal resistance have been obtained numerically. The paper presents results of heat calculation of various BHE designs in accordance with the proposed method.

  1. Further understanding of twisted tape effects as tube insert for heat transfer enhancement

    Science.gov (United States)

    Abu-Khader, Mazen M.

    2006-12-01

    Tube inserts are used as heat transfer enhancement tool for both retrofit and new design of shell and tube heat exchangers. This paper discusses and reviews the characteristics and performance of twisted tapes. The theory and application are also addressed. Industrial case study was selected to illustrate the behaviour effect that the twisted tapes impose at various laminar, transition and turbulent flow regions. This effect was demonstrated by changing the inside tube diameter and twist ratio through evaluating selected exchanger design parameters such as: local heat transfer coefficient, friction factor and pressure drop. Testing the exponent powers for Re and Pr at both laminar and turbulent regions were carried out. General design considerations are outlined for the use of twisted tapes in shell and tube heat exchangers.

  2. Numerical Simulation of Flow in Shell Side of Shell-and-Tube Heat Exchangers with Helical Baffles%螺旋折流板换热器壳侧流动的数值模拟

    Institute of Scientific and Technical Information of China (English)

    邓斌; 吴扬; 陶文铨

    2004-01-01

    采用多孔介质、分布阻力模型、阶梯逼近技术对螺旋折流板换热器壳侧的流动进行了三维数值模拟,湍流方程组的求解采用了改进的k-ε模型和壁面函数法.数值模拟结果表明,在相同的进口内径及相同的进口流量条件下,螺旋折流板换热器壳侧的压降明显低于弓形折流板换热器的,且随着螺旋角的增加,压降呈减小的趋势.在小流量条件下,计算所得的换热器进出口总压降与实验值之间的偏差大部分在14% 以下,最大为18%,能符合工程计算的需要.

  3. Simulation of Flow Characteristic and Structural optimization of Shell and Tube Heat Exchanges%管壳式换热器流动特性仿真模拟及结构优化

    Institute of Scientific and Technical Information of China (English)

    周伟; 王庆明

    2009-01-01

    运用SoliWorks中的流体仿真模拟插件Cosmosfloworks对管壳式换热器的流动特性进行仿真模拟,对管壳式换热器的管束腐蚀情况进行研究.首先通过sofidWorks对管壳式换热器进行实体建模,然后结合流体仿真模拟插件Cosmosfloworks完成流体仿真计算,最后得出导致腐蚀的原因并提出管壳式换热器的结构优化方案.

  4. Research on Thermal-structural Coupling Field Numerical Simulation of Large Shell and Tube Heat Exchanger%大型管壳式换热器热-结构耦合场数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    舒志君; 姜孝旺; 刘云艳

    2013-01-01

    将换热器最严酷工况的表面温度数据添加到换热器的有限元数值模拟模型上,通过导热计算得出换热器各部分的热场分布,然后求出由于热场而产生的变形.将热场产生的变形与换热器结构场载荷而产生的变形进行耦合分析,这样就可得出换热器热-结构耦合场的变形和应力分布,从而验证换热器设计的合理性.

  5. Three - dimensional shell flow field numerical simulation of shell-and-tube heat exchanger by FLUENT software%FLUENT软件模拟管壳式换热器壳程三维流场

    Institute of Scientific and Technical Information of China (English)

    刘利平; 黄万年

    2006-01-01

    基于各向异性多孔介质与分布阻力模型、修正k-ε模型和壁面函数法,对普通管壳式换热器壳程流体的流动与传热,利用FLUENT软件进行了三维数值模拟.计算了不同流体初速下,管壳式换热器壳程的速度场、温度场和压力场,计算结果与实际情况相符,得到了有参考价值的结论.

  6. 折流板开孔改进管壳式换热器性能的CFD分析%Analysing the effect of drilling holes on the baffles of shell-and-tube heat exchanger based on the CFD

    Institute of Scientific and Technical Information of China (English)

    熊智强; 喻九阳; 曾春

    2006-01-01

    利用计算流体动力学(CFD)技术对管壳式换热器弓形折流板附近流场进行了数值模拟,发现在弓形折流板背面,有部分区域的流速较低,一定程度上存在着流动死区.采用在弓形折流板上开孔的方法后,CFD计算结果显示其传热效率提高了5.4%,壳侧压降减小了7.3%.

  7. 管壳式换热器壳程特性数值模拟%Numerical simulation on characteristics in shell side of shell-and-tube heat exchanger

    Institute of Scientific and Technical Information of China (English)

    王丹; 董其伍; 刘敏珊

    2009-01-01

    通过合理简化,建立管壳式换热器的实体模型,用大型CFD(computational fluid dynamics)软件FLUENT对于管壳式换热器壳程的流体流动与传热性能进行数值模拟研究.利用判断周期性充分发展段的3个主要特征,分别从压力差、无因次温度、速度3个方面,分析具有不同流体速度、不同流体介质、不同折流板间距时几种折流板管壳式换热器模型的进出口段对于壳程流体流动与传热性能的影响.结果表明,管壳式换热器结构一定的情况下,进出口段对壳程流体流动和传热周期性充分发展段的影响长度不随壳程流体性质、流动速度的变化而变化;随着折流板间距与筒体内径的比值增大而增大.

  8. 纵流式管壳式换热器传热与流动特性的3D数值模拟研究%3D Numerical Simulation Study on Shell-and-tube Heat Exchangers with Longitudinal Flows

    Institute of Scientific and Technical Information of China (English)

    吴志伟; 洪宇翔; 杜娟

    2013-01-01

    文章运用CFD软件Fluent分析了三种支撑结构对壳程性能的影响,可为工业用纵流式管壳式换热器优化及强化传热提供依据.文章探讨了水在三种不同支撑结构下的流阻与传热性能,得到不同支撑结构具有不同的传热效果,螺旋片相对其它两种支撑方式更有利于提高传热综合性能,并进一步对这三种换热器的传热强化机理进行了探讨.

  9. Optimal Design of Shell-and-tube Heat Exchangers Based on Process Simulation Software%基于过程模拟软件的管壳式换热器优化设计

    Institute of Scientific and Technical Information of China (English)

    李保红; 张珏庭

    2010-01-01

    提出基于国际流行的ASPEN PLUS模拟软件,通过与必要的手工计算相结合,高效地设计出符合中国相关标准管壳式换热器的步骤和方法.复杂而且繁琐的能量平衡和压力降计算由软件来完成,设计者只需依照相关的标准,通过简单的手工计算确定出离散变量的取值,再基于模拟软件的计算结果,在压力降和标准许可的范围内,调整离散变量的取值以便进一步提高总传热系数,从而节省传热面积.通过重新设计一个文献实例来演示所提方法的简单性和有效性,所得的换热面积比报道值节省了66.7%.

  10. Simulation and economic analysis of a liquid-based solar system with a direct-contact liquid-liquid heat exchanger, in comparison to a system with a conventional heat exchanger

    Science.gov (United States)

    Brothers, P.; Karaki, S.

    Using a solar computer simulation package called TRNSYS, simulations of the direct contact liquid-liquid heat exchanger (DCLLHE) solar system and a system with conventional shell-and-tube heat exchanger were developed, based in part on performance measurements of the actual systems. The two systems were simulated over a full year on an hour-by-hour basis at five locations; Boston, Massachusetts, Charleston, South Carolina, Dodge City, Kansas, Madison, Wisconsin, and Phoenix, Arizona. Typically the direct-contact system supplies slightly more heat for domestic hot water and space heating in all locations and about 5 percentage points more cooling as compared to the conventional system. Using a common set of economic parameters and the appropriate federal and state income tax credits, as well as property tax legislation for solar systems in the corresponding states, the results of the study indicate for heating-only systems, the DCLLHE system has a slight life-cycle cost disadvantage compared to the conventional system. For combined solar heating and cooling systems, the DCLLHE has a slight life-cycle cost advantage which varies with location and amounts to one to three percent difference from the conventional system.

  11. Bistability in radiative heat exchange

    Science.gov (United States)

    Rudakov, V. I.; Ovcharov, V. V.; Prigara, V. P.

    2008-08-01

    The possibility of a bistable regime in systems with radiative heat exchange is theoretically demonstrated for the first time. The transfer characteristics of a radiation-closed stationary system have been calculated, in which the radiator is a blackbody and the absorber is made of a material with the absorptivity sharply increasing in a certain temperature interval. The radiator and absorber are separated by a vacuum gap. The heat exchange between the system and the environment is controlled by varying the flow rate of a heat-transfer agent cooling the absorber. The output parameter of a bistable system is the absorber temperature, while the input parameter can be either the radiator temperature or the heat-transfer agent flow rate. Depending on the choice of the input parameter, the transfer characteristic of the system is either represented by a usual S-like curve or has an inverted shape.

  12. [Biofouling of heat exchange tubes].

    Science.gov (United States)

    Montero, F; Pintado, J L

    1994-01-01

    We compared the biofouling behavior of different materials (admiralty brass, stainless steel, and titanium) commonly used to construct heat exchangers in thermoelectric plants. The incidence of film formation on the loss of heat during transference was assessed, and analyzed in terms of plant efficiency and corrosion, both general and localized development. Our results showed that the resistance of titanium and stainless steel to corrosion was similar, and much better than that of admiralty brass. Biofouling, however, was higher in the first two materials.

  13. Calculations of Shipboard Heat Exchangers,

    Science.gov (United States)

    1980-04-18

    Constrained moticn is created by the external exciting forces - pumps, compresors , fars, agitators. During the heat exchange distinguish the phenomena...cast tcttozs. (5). fcr fla*/plane covers/caps. FOOTNOTE 1. Is taken stall value. !NDFOCINOIE. Additional requirements fox the dished bcttcss. -w j DOC

  14. Development of Design Criteria for Fluid Induced Structural Vibration in Steam Generators and Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Catton, Ivan; Dhir, Vijay K.; Alquaddoomi, O.S.; Mitra, Deepanjan; Adinolfi, Pierangelo

    2004-03-26

    OAK-B135 Flow-induced vibration in heat exchangers has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported through the USNRC incident reporting system. Almost all heat exchangers have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-induced vibration is constantly updated with new findings and improved design criteria for heat exchangers. In the nuclear industry, steam generators are often affected by this problem. However, flow-induced vibration is not limited to nuclear power plants, but to any type of heat exchanger used in many industrial applications such as chemical processing, refrigeration and air conditioning. Specifically, shell and tube type heat exchangers experience flow-induced vibration due to the high velocity flow over the tube banks. Flow-induced vibration in these heat exchangers leads to equipment breakdown and hence expensive repair and process shutdown. The goal of this research is to provide accurate measurements that can help modelers to validate their models using the measured experimental parameters and thereby develop better design criteria for avoiding fluid-elastic instability in heat exchangers. The research is divided between two primary experimental efforts, the first conducted using water alone (single phase) and the second using a mixture of air or steam and water as the working fluid (two phase). The outline of this report is as follows: After the introduction to fluid-elastic instability, the experimental apparatus constructed to conduct the experiments is described in Chapter 2 along with the measurement procedures. Chapter 3 presents results obtained on the tube array and the flow loop, as well as techniques used in data processing. The project performance is described and evaluated in Chapter 4 followed by

  15. Shellside flow-induced tube vibration in typical heat exchanger configurations: overview of a research program

    Energy Technology Data Exchange (ETDEWEB)

    Halle, H.; Chenoweth, J.M.; Wambsganss, M.W.

    1986-01-01

    A comprehensive research program is being conducted to develop the necessary criteria to assist designers and operators of shell-and-tube heat exchangers to avoid detrimental flow-induced tube vibration. This paper presents an overview of the insights gained from shellside water-flow testing on a horizontal, industrial-sized test exchanger that can be configured in many ways using interchangeable tube bundles and replaceable nozzles. Nearly 50 different configurations have been tested representing various combinations of triangular, square, rotated-triangular, and rotated-square tubefield layouts; odd and even numbers of crosspasses; and both single- and double-segmental baffles with different cut sizes and orientations. The results are generally consistent with analytical relationships that predict tube vibration response by the combined reinforcing effect of the vibration mode shape and flow velocity distribution. An understanding of the vibration and instability performance is facilitated by recognizing that the excitation is induced by three separate, though sometimes interacting, flow conditions. These are the crossflows that generate ''classic'' fluidelastic instabilities in the interior of the tube bundle, the entrance and exit bundle flow from and into the shell nozzles, and the localized high velocity bypass and leakage stream flows. The implications to design and/or possible field remedies to avoid vibration problems are discussed. 17 refs., 10 figs.

  16. Modelling of a shell-and-tube evaporator using the zeotropic mixture R-407C

    Energy Technology Data Exchange (ETDEWEB)

    Necula, H.; Badea, A. [Universite Politecnica de Bucarest (Romania). Faculte d' Energetique; Lallemand, M. [INSA, Villeurbanne (France). Centre de Thermique de Lyon; Marvillet, C. [CEA-Grenoble (France)

    2001-11-01

    This study concerns the steady state modelling of a shell-and-tube evaporator using the zeotropic mixture R-407C. In this local type model, the control volumes are a function of the geometric configuration of the evaporator in which baffles are fitted. The validation of the model has been made by comparison between theoretical and experimental results obtained from an experimental investigation with a refrigerating machine. For test conditions, the flow pattern has been identified from a flow pattern map as being stratified. Theoretical results show the effect of different parameters such as the saturation pressure, the inlet quality, etc. on the local variables (temperature, slip ratio). The effect of leakage on the mixture composition has also been investigated. (author)

  17. Selection and Use of New Type of Heat Exchanger in Sulfuric Acid Production with Sulfur%硫黄制酸装置中新型换热器的选择与应用

    Institute of Scientific and Technical Information of China (English)

    王艳红

    2015-01-01

    By analyzing process features of the low resistance,high efficiency,sharp expansion and accelerated flow convergent-divergent tube shell-and-tube heat exchanger,and based on problems in actual operation of sulfur-burning sulfuric acid plant,the first heat exchanger in conversion system is transformed into a hollow ring type shell-and-tube heat exchanger with converging-diverging tubes. After the revamp,compared with conventional tube heat exchanger,heat transfer area can be reduced, the resistance of the heat exchanger,system energy consumption,operation cost and sulfuric acid production cost are decreased,and good environmental benefits and social benefits are obtained.%通过对低阻高效急扩加速流缩放管管壳式换热器的技术特点的分析并结合硫黄制酸装置的实际运行中存在的问题,将转化系统第1冷热换热器改造为采用缩放管管束的空心环管壳式换热器。改造后,与传统列管式换热器相比,可减小传热面积,降低换热器阻力、系统能耗、操作费用和硫酸生产成本,取得了良好的环境效益和社会效益。

  18. Experimental study on heat exchange of several types of exchangers

    Institute of Scientific and Technical Information of China (English)

    周志华; 赵振华; 于洋

    2009-01-01

    Aiming at the ground-coupled source heat pump that possesses the shortcomings of occupying larger land,this article studies the heat exchanged of heat exchanger in piling,and compares it with common heat exchangers buried directly. The result indicates that the heat exchanger makes the best use of structure of building,saves land,reduces the construction cost,and the heat exchanged is obviously more than exchangers buried directly. In winter condition,when W-shape pipe heat exchanger in pile foundation is 50 m deep and diameter is 800 mm,it transfers 1.2-1.3 times as large as the one of single U-shape buried directly at the flow rate of 0.6 m/s,whose borehole diameter is 300 mm. And in summer condition it does about 2.0-2.3 times as that of U-shape one.

  19. An analytical study of heat exchanger effectiveness and thermal performance in a solar energy storage system with PCM

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.C.Y.; Kwok, C.C.K.; Lin, S.; Vatistas, G.H.

    1984-05-01

    Solar thermal energy storage systems can be categorized based on materials that store either as sensible heat or as latent heat of fusion. For convenience, the latter are designated as phase change materials (PCM). It is a fairly well accepted fact that PCM storage devices usually require less storage volume. In a recent paper, heat exchanger effectiveness for PCM storage units was theoretically derived and presented in chart form. The heat exchanger considered was a shell-and-tube type, viz., the shell side filled with PCM and the tube side with heating or cooling fluid. The PCM heat storage system presented here, however, involves both heating and cooling fluids with a PCM in the middle composed of rectangular channels. This system may be used to store the thermal energy absorbed by a solar collector for the purpose of heating a building. The thermal energy carried by a hot fluid coming from the solar collector can be transferred through the upper surface I. The thermal energy stored in the system can be extracted through the lower surface II by a cold fluid circulating through the building. In order to transfer heat to the melting PCM, the temperature of the hot fluid must be higher than the melting point of the PCM, T /SUB m/ , and to remove heat from the solidifying PCM, the temperature of the cold fluid must be lower than T /SUB m/ . Therefore, the melting point of the PCM presents a limitation of the temperature of both the hot and cold fluids. This temperature limitation is more or less similar to the temperature restriction of a parallel-flow heat exchanger, in which the final temperature of the cold fluid can never reach the outlet temperature of the hot fluid.

  20. Acoustic streaming with heat exchange

    Science.gov (United States)

    Gubaidullin, A. A.; Pyatkova, A. V.

    2016-10-01

    Acoustic streaming in a cylindrical cavity with heat exchange is numerically investigated. The cavity is filled with air. The boundaries of the cavity are maintained at constant temperature. The features of acoustic streaming manifesting with the decrease in the frequency of vibration in comparison with the resonant frequency are determined. The influence of the nonlinearity of process on acoustic streaming is shown. The nonlinearity is caused by the increase of the vibration amplitude.

  1. Optimal design of the separate type heat pipe heat exchanger

    Institute of Scientific and Technical Information of China (English)

    YU Zi-tao; HU Ya-cai; CEN Ke-fa

    2005-01-01

    Separate type heat pipe heat exchangers are often used for large-scale heat exchanging. The arrangement of such a heat exchanger conveniently allows heat input to and output from the heat exchanger at remote locations. The traditional method of designing an ordinary HPHE (heat pipe heat exchanger) is commonly applied in the separate type exchanger design, but the calculations have to be carried out separately, which makes it very complicated. In this work, the ε-NTU (effectiveness-Number of Transfer Units) method was applied for optimization analysis of single- or multi-level separate type heat pipe heat exchangers. An optimizing formula for single-level separate type heat pipe heat exchangers was obtained. The optimizing principles of effectiveness-NTU and heat transfer rate by the equal distribution method for multi-level separate type heat pipe heat exchanger are presented. The design of separate type heat pipe heat exchangers by the optimizing method is more convenient and faster than by the traditional method.

  2. Cryogenic Heat Exchanger with Turbulent Flows

    Science.gov (United States)

    Amrit, Jay; Douay, Christelle; Dubois, Francis; Defresne, Gerard

    2012-01-01

    An evaporator-type cryogenic heat exchanger is designed and built for introducing fluid-solid heat exchange phenomena to undergraduates in a practical and efficient way. The heat exchanger functions at liquid nitrogen temperature and enables cooling of N[subscript 2] and He gases from room temperatures. We present first the experimental results of…

  3. SAFE gas turbine cycle primary heat exchangers

    Science.gov (United States)

    Reid, Robert S.; Kapernick, Richard J.

    2002-01-01

    Los Alamos National Laboratory and Marshall Space Flight Center are jointly developing two modular heat pipe heat exchangers, collectively named FIGMENT (Fission Inert Gas Metal Exchanger for Non-nuclear Testing). The FIGMENT heat exchangers are designed to transfer power from the SAFE nuclear reactor cores to gas turbine energy converters. A stainless steel prototype heat exchanger will be built during 2002 in preparation for the construction of a larger refractory metal version. Two promising FIGMENT stainless steel heat exchanger concepts are reviewed here. .

  4. Finned Small Diameter Tube Heat Exchanger

    Science.gov (United States)

    Dang, Chaobin; Daiguji, Hirofumi; Hihara, Eiji; Tokunaga, Masahide

    The performance of fined small tube heat exchangers was investigated both experimentally and theoretically. The Inner diameters of tubes were 1.0mm, 2.1mm and 4.0mm. Exchanged heat and pressure drop obtained from numerical simulation agreed well with the experimental ones. Calculation results show that the volume of a 2.0mm tube heat exchanger can be reduced to 33% of that of a 4mm tube heat exchanger with the same capacity. In addition the distribution of two-phase flow in a branching unit was investigated by measuring downstream temperature distribution. The flow distribution in a branching unit strongly affects the exchanged heat.

  5. CFD Modeling of Sodium-Oxide Deposition in Sodium-Cooled Fast Reactor Compact Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Tatli, Emre; Ferroni, Paolo; Mazzoccoli, Jason

    2015-09-02

    The possible use of compact heat exchangers (HXs) in sodium-cooled fast reactors (SFR) employing a Brayton cycle is promising due to their high power density and resulting small volume in comparison with conventional shell-and-tube HXs. However, the small diameter of their channels makes them more susceptible to plugging due to Na2O deposition during accident conditions. Although cold traps are designed to reduce oxygen impurity levels in the sodium coolant, their failure, in conjunction with accidental air ingress into the sodium boundary, could result in coolant oxygen levels that are above the saturation limit in the cooler parts of the HX channels. This can result in Na2O crystallization and the formation of solid deposits on cooled channel surfaces, limiting or even blocking coolant flow. The development of analysis tools capable of modeling the formation of these deposits in the presence of sodium flow will allow designers of SFRs to properly size the HX channels so that, in the scenario mentioned above, the reactor operator has sufficient time to detect and react to the affected HX. Until now, analytical methodologies to predict the formation of these deposits have been developed, but never implemented in a high-fidelity computational tool suited to modern reactor design techniques. This paper summarizes the challenges and the current status in the development of a Computational Fluid Dynamics (CFD) methodology to predict deposit formation, with particular emphasis on sensitivity studies on some parameters affecting deposition.

  6. Comparison of a Conventional Heat Exchangers with a New Designed Heat Exchanger Experimentally

    Directory of Open Access Journals (Sweden)

    Tansel Koyun

    2014-04-01

    Full Text Available In this study, the air-water heat exchanger designed have been experimentally compared to conventional heat exchangers with and without fin. The same parameters for the three heat exchangers (pump flow, heating power, etc... have been used. In the experiments, speed-flow adjustment has been made to supply heat transfer at an optimum. As a result, during the circulation of water in pipe of the air-water heat exchanger, the corrosion fouling factor has not been formed. In addition, the efficiency of the new designed heat exchanger has been found between fin and finless heat exchanger efficiencies. The results have been shown in the diagrams.

  7. 基于气液两相流入口蒸汽参数对管壳式冷凝器性能的影响%The Effect to the Performance of Shell-and-tube Condenser of Inlet Steam Parameters Based on Gas-liquid Two-phase Flow

    Institute of Scientific and Technical Information of China (English)

    黄国权; 戈锐; 李想; 张玉宝

    2012-01-01

    采用数值模拟方法,使用CFD软件FLUENT对管壳式冷凝器壳侧按两相流动及相变传热进行了模拟计算,选定合适的湍流模型、两相流模型为混合物模型,并根据汽水转化公式编写了自定义函数UDF来描述相变过程质和量的传递.针对壳侧流体介质为高温饱和水蒸汽情况下,分别对不同的介质入口速度和入口温度情况下换热器壳侧传热系数、湍流动能和压强变化的模拟结果进行了比较,得出了流体介质入口速度与温度对换热器壳侧传热特点和传热性能的影响规律.从而对冷凝器壳侧结构参数的优化及流动介质进行合理的选择起到指导作用.%Numerical-simulation methods are adopted here.With the help of CFD and FLUENT software, the two-phase flow and phase change and heat transfer is simulatedA turbulence model and a two-phase flow model are selected. Based on the characteristics of shell-side in the shell-and-tube condenser, User梔efined Function (UDF)is introduced to describe the phase transition of quality and quantity through the use of the conversion formula, analyzing the influence on the condenser coefficients and its pressure. Choosing saturated vapor as the liquid medium at the inlet of shell-side of the shell-and-tube heat exchangers , it focuses on comparing the simulation results on the heat coefficient,turbulent momentum and pressure distribution of the shell-and梩ube heat exchangers at the inlet.The experimental results reveal the influence law of the velocity and temperature of fluid medium inlet to the characteristics and the performance of the heat exchanger shell side.These provide some valuable references to the improvement of tube condenser structure parameter optimization, and the choice of flow media

  8. NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

    2008-09-01

    One key long-standing issue that must be overcome to fully realize the successful growth of nuclear power is to determine other benefits of nuclear energy apart from meeting the electricity demands. The Next Generation Nuclear Plant (NGNP) will most likely be producing electricity and heat for the production of hydrogen and/or oil retrieval from oil sands and oil shale to help in our national pursuit of energy independence. For nuclear process heat to be utilized, intermediate heat exchange is required to transfer heat from the NGNP to the hydrogen plant or oil recovery field in the most efficient way possible. Development of nuclear reactor - process heat technology has intensified the interest in liquid metals as heat transfer media because of their ideal transport properties. Liquid metal heat exchangers are not new in practical applications. An important rational for considering liquid metals is the potential convective heat transfer is among the highest known. Thus explains the interest in liquid metals as coolant for intermediate heat exchange from NGNP. For process heat it is desired that, intermediate heat exchangers (IHX) transfer heat from the NGNP in the most efficient way possible. The production of electric power at higher efficiency via the Brayton Cycle, and hydrogen production, requires both heat at higher temperatures and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. Compact heat exchangers maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. High temperature IHX design requirements are governed in part by the allowable temperature drop between the outlet and inlet of the NGNP. In order to improve the characteristics of heat transfer, liquid metal phase change heat exchangers may be more effective and efficient. This paper explores the overall heat transfer characteristics and pressure drop of the phase change

  9. 压水堆余热排出换热器性能研究%Numerical Investigation of Residual Heat Removal Heat Exchange Capacity in Pressurized Water Reactor Plants

    Institute of Scientific and Technical Information of China (English)

    丘锦萌; 李军; 王晓江; 王志刚

    2013-01-01

    以压水堆余热排出系统为对象,建立管壳式换热器的数学模型.与换热器设计软件HTRI的计算结果进行对比,结果表明该模型可以准确预测管壳式换热器的管壳侧出口温度.总传热系数敏感性计算表明,该参数随管壳侧流量变化而变化,在换热器性能预测时不能当作常数处理,应与工况进行耦合计算.当管壳侧体积流量小于1000 m3/h时,总传热系数对流量较为敏感;当体积流量大于1000m3/h时,流量的影响则相对较弱.该模型为预测换热器其他工况的换热性能提供基础,为换热设备调试提供指导,为核电厂设计验证及高效安全运行提供可靠依据.%Mathematical model is established for shell and tube heat exchanger of PWR residual heat removal system. Comparison with the calculated results from the design software HTRI for the heat exchanger is conducted, and the results show that outlet temperatures of shell and tube side are precisely predicted. The calculation of overall heat exchanger coefficient sensibility shows that this parameter varies with the flow rates of tube and shell side and it is not advisable to keep it as constant value in the simulation. The overall heat exchanger coefficient shall be coupled with the heat exchanger flow and heat exchanging conditions during calculation. The overall coefficient is extremely dependent on the flowrates which is less than 1000 m3/h while it seems to be independent with the higher flowrates. The model can be easily employed to predict other system conditions elsewhere and provide the convenient way for the plant test, design verification and high efficient operation of nuclear power plants.

  10. Discontinuous Operation of Geothermal Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    方肇洪; 刁乃仁; 崔萍

    2002-01-01

    Ground-source heat pump (GSHP) systems for HVAC have aroused more and more interest in China in recent years because of their higher energy efficiency compared with conventional systems. The design and performance simulation of the geothermal heat exchangers is vital to the success of this technology. In GSHP systems, the load of the geothermal heat exchanger varies greatly and is usually discontinuous even during a heating or cooling season. This paper outlines a heat transfer model for geothermal heat exchangers. The model was used to study the influence of the discontinuous operation of the heat pumps on the performance of the geothermal heat exchangers. A simple and practical approach is presented for sizing the geothermal heat exchangers.

  11. Mathematical simulation of heat exchanger working conditions

    Science.gov (United States)

    Gavlas, Stanislav; Ďurčanský, Peter; Lenhard, Richard; Jandačka, Jozef

    2015-05-01

    One of the When designing a new heat exchanger it is necessary to consider all the conditions imposed on the exchanger and its desired properties. Most often the investigation of heat transfer is to find heat surface. When applying exchanger for proposed hot air engine, it will be a counter-flow heat exchanger of gas - gas type. Gas, which transfers the heat will be exhaust gas from the combustion of biomass. An important step in the design and verification is to analyze exchanger designed using numerical methods, the verification of the correctness of design and verification of boundary conditions which include temperatures, flow rates and pressure drops. Due to the fact that the heat transfer in the heat exchanger is a three-dimensional plot and timeindependent, the system is described by partial differential equations that need to be solved by numerical methods.

  12. Direct contact heat exchangers for space

    Science.gov (United States)

    Taussig, R. T.; Thayer, W. J.; Lo, V. C. H.; Sakins, K. M.; Bruckner, A. P.

    1985-06-01

    Direct contact heat exchanger concepts have been investigated for use in space, including droplet vortex heat exchangers, coflowing droplet heat exchangers, electrostatically driven heat exchangers, and belt and disk heat exchangers. These concepts are characterized by a low heat exchanger mass per unit of heat transferred, low pressure losses, high reliability, and compactness in design. Operation in zero-G poses unique problems for those direct contact heat exchangers which require separation of two fluid media after heat transfer is completed. Other problems include maintenance of good heat transfer coefficients in the absence of buoyant forces, exposure of heat transfer media to vacuum conditions for certain applications, and materials compatibility. A preliminary systems analysis indicates the potential for substantial weight reductions in turbine Brayton cycle space power systems for output powers above several MW(e). Based on the status of current technology and the results of this analysis, recommendations are made for the most attractive applications and the R&D required to ready a direct contact heat exchanger for use in space.

  13. Micro tube heat exchangers for Space Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mezzo fabricates micro tube heat exchangers for a variety of applications, including aerospace, automotive racing, Department of Defense ground vehicles, economizers...

  14. Study on Single-tube Spiral Heat Exchanger%单管式螺旋管热交换器仿真研究

    Institute of Scientific and Technical Information of China (English)

    李成植; 金莹

    2013-01-01

    通过有限元软件计算了单管式螺旋管热交换器的内部流场和温度场,探讨了管程入口介质流量、介质温度以及螺旋管圈数对其换热效率的影响.结果表明,螺旋管热交换器的换热效率明显优于直管式热交换器,螺旋管圈数对换热效率并无明显的影响,但会显著地增加管程的沿程压力降;壳-管之间的换热主要发生在管程的入口附近,因此可进一步缩小热交换器的轴向尺寸;壳-管程的进口温差越大,螺旋管热交换器的换热效果就越好,但为了避免螺旋管入口附近过度的热应力集中现象,有必要适当调整壳程入口的方位,以免壳程入口冷空气直接冲刷管程入口.%Single spiral tube heat exchanger has been developed for improving heat exchange efficiency of shell-and-tube heat exchanger and reducing complexity of structure of heat exchanger. Flow field and temperature field of the heat exchanger have been calculated by using finite element software, and it has been investigated of the influence on heat exchange efficiency of inlet flow of tube side, temperature and the cycle number of spiral pipe. The results showed that the heat exchange efficiency of spiral-tube heat exchanger has been much better than that of straight-tube heat exchanger, but the cycle number of spiral pipe has no significant impact for heat exchange efficiency, and has remarkably increased the pressure drop along the way of the tube side. The heat exchange between shell and tube has mostly happened near the entrance, thus it could make axial dimension of the heat exchanger reduced further. The greater the temperature difference of the entrance between shell side and tube side has been, the better the heat exchange efficiency of spiral-tube heat exchanger has been. However, for avoiding excessive thermal stress concentration near entrance of spiral tube, it has been necessary of adjusting entrance orientation of shell side properly for fear that

  15. New models for conventional and heat exchangers enhanced with tube inserts for heat exchanger network retrofit

    OpenAIRE

    Jiang, N; Shelley, J D; Smith, Robin

    2014-01-01

    The retrofit of heat exchanger networks requires detailed models of the heat exchangers for the detailed assessment of network performance. Network retrofit options include heat transfer enhancement. There is thus a requirement for detailed models of heat exchanger performance, including heat transfer enhancement, suitable for inclusion in network retrofit optimization algorithms. Such models must be robust, computationally efficient and accurate enough to reflect the heat transfer and pressu...

  16. Conjugate heat and mass transfer in heat mass exchanger ducts

    CERN Document Server

    Zhang, Li-Zhi

    2013-01-01

    Conjugate Heat and Mass Transfer in Heat Mass Exchanger Ducts bridges the gap between fundamentals and recent discoveries, making it a valuable tool for anyone looking to expand their knowledge of heat exchangers. The first book on the market to cover conjugate heat and mass transfer in heat exchangers, author Li-Zhi Zhang goes beyond the basics to cover recent advancements in equipment for energy use and environmental control (such as heat and moisture recovery ventilators, hollow fiber membrane modules for humidification/dehumidification, membrane modules for air purification, desi

  17. Probe Measures Fouling As In Heat Exchangers

    Science.gov (United States)

    Marner, Wilbur J.; Macdavid, Kenton S.

    1990-01-01

    Combustion deposits reduce transfer of heat. Instrument measures fouling like that on gas side of heat exchanger in direct-fired boiler or heat-recovery system. Heat-flux probe includes tube with embedded meter in outer shell. Combustion gases flow over probe, and fouling accumulates on it, just as fouling would on heat exchanger. Embedded heat-flow meter is sandwich structure in which thin Chromel layers and middle alloy form thermopile. Users determine when fouling approaches unacceptable levels so they schedule cleaning and avoid decreased transfer of heat and increased drop in pressure fouling causes. Avoids cost of premature, unnecessary maintenance.

  18. Numerical Analysis on Enhanced Heat Transfer of the Segmental Baffle in the Shell Side of the Heat Exchanger%弓形折流板强化换热器壳程传热数值分析

    Institute of Scientific and Technical Information of China (English)

    张江勇; 苏慧; 孟强

    2012-01-01

    为了分析弓形折流板强化换热器壳程传热机制,在原换热器模型的基础上增设了折流板.利用FLUENT软件建立弓形折流板换热器的三维模型,模拟得到不同工况下的换热器温度场、流场分布图及传热量、总传热系数等相关数据.将上述数据与原模型数值模拟结果进行对比,结果表明:弓形折流板强化换热器壳程传热效果明显,验证了换热器结构优化的合理性和必要性.%In order to analyze the enhanced heat transfer mechanism of segmental baffle in the shell side of the heat exchanger, segmental baffles were added to optimize the design of the original model of shell-and-tube heat exchanger. The three-dimension models of the segmental baffle heat exchangers were set up using FLUENT software, and distribution maps of temperature field and flow field, relevant datas including the capacity of heat transmission and the total heat transfer coefficient in different conditions were gotten. Comparing the numerical simulation results with the original model data, it is shown that the enhanced heat exchanger effect of segmental baffles in the shell side of the heat exchanger is obvious. So the structure optimization of heat exchanger is' necessary and rational.

  19. Structure Optimization for Heat Exchanger Baffle Based on Computational Fluid Dynamics Simulation of Thermal-Fluid-Structure Coupling%基于计算流体力学热流固耦合仿真的换热器折流板结构优化

    Institute of Scientific and Technical Information of China (English)

    张仂; 谷芳

    2012-01-01

    采用多物理场耦合方法,建立了管壳式换热器的计算流体力学(CFD)热流固耦合仿真分析模型,对20种不同折流板结构参数的管壳式换热器进行了流动与传热的数值模拟.CFD仿真计算结果显示,换热器的折流板间距和折流板缺口高度对流动和传热的影响相互关联,不能进行单目标优化设计.以JF因子作为换热器综合性能的评价准则,对管壳式换热器的折流板间距和折流板缺口高度进行了结构优化设计,提出在换热器内径(d)200 mm、换热管长1140 mm、并流条件下,该换热器的最佳折流板间距为80 mm(折流板数目为10),最佳折流板缺口高度为0.3d(即60 mm).%A thermal-fluid-structure coupling simulation model for shell-and-tube heat exchangers was established based on computational fluid dynamics(CFD) by a multi-physical field coupling method. The flow and heat transfer in 20 different types of shell-and-tube heat exchangers with different baffle structural parameters were simulated by the model. The CFD simulation results showed that the effects of the baffle spacing and baffle gap height on the flow and heat transfer interconnected, which showed that the single-objective optimization could not be achieved. With JF factors as the evaluation criteria of the heat exchanger performances, the baffle spacings and baffle gap heights in the shell-and-tube heat exchangers were optimized. It was put forward that under the conditions of parallel flow, inside diameter of the heat exchanger(d)200 mm and heat exchange tube length 1 140 mm, the baffle space and baffle gap height were 80 mm(the baffle number 10) and 0.3d(60 mm), respectively.

  20. Development of high effectiveness droplet heat exchangers

    Science.gov (United States)

    Thayer, W. J., III; Sekins, K. M.; Bruckner, A. P.

    1985-04-01

    An experimental and analytical investigation has been carried out to assess the feasibility of developing high effectiveness, high temperature droplet heat exchangers and to identify practical applications for this type of direct contact heat exchanger. The droplet heat exchanger (DHX) concept studies uses a counterflowing gas and droplet configuration, uniformly sized droplets or particles, and a uniform dispersion of droplets in gas to achieve high heat exchanger effectiveness. Direct contact between the heat transfer media eliminates the solid heat transfer surfaces that are used in conventional heat exchangers and is expected to make very high temperature heat transfer practical. Low temperature simulation tests and analysis have been used to demonstrate that uniformly sized droplets can be generated over a wide range of fluid properties and operating conditions appropriate for high temperature droplet heat exchanger applications. One- and two-dimensional, two-phase flow and heat transfer computer models have been developed and used to characterize both individual component configurations and overall DHX heat transfer rates and effectiveness. The computer model and test data began to diverge as the operating pressure was increased, indicating a need for more general transport rate correlations and a better understanding of the two-phase flows that govern DHX operation.

  1. Heat Exchanger Lab for Chemical Engineering Undergraduates

    Science.gov (United States)

    Rajala, Jonathan W.; Evans, Edward A.; Chase, George G.

    2015-01-01

    Third year chemical engineering undergraduate students at The University of Akron designed and fabricated a heat exchanger for a stirred tank as part of a Chemical Engineering Laboratory course. The heat exchanger portion of this course was three weeks of the fifteen week long semester. Students applied concepts of scale-up and dimensional…

  2. Research and Development of Heat Exchanger with Efficient Perforated Straight (Corrugated) and Internal Finned-tubes%开孔平直(波纹)高效内翅管热交换器的研究开发

    Institute of Scientific and Technical Information of China (English)

    冯苗根; 何建龙

    2012-01-01

    对几种不同结构内翅管的传热和阻力特性进行了实验分析,通过工程实际计算应用比较,揭示了高效内翅管的优越性,提出了采用开孔平直(波纹)内翅管替代原光管作为新一代列管式热交换器的发展方向.%Through analysis by both heat transfer & resistance characteristic experiments of several internal finned-tubes with different structures and comparison between the calculations applied in real projects, this paper discloses the superiority of efficient internal finned-tube and proposes the development of new generation of shell and tube heat exchanger equipped with perforated, straight (corrugated) and internal finned-tubes instead of previous tubes without fins.

  3. Testing and plugging power plant heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Sutor, F. [Expando Seal Tools, Inc., Montgomeryville, PA (United States)

    1994-12-31

    Heat Exchanger tubes fail for any number of reasons including but certainly not limited to the cumulative effects of corrosion, erosion, thermal stress and fatigue. This presentation will attempt to identify the most common techniques for determining which tubes are leaking and then introduce the products in use to plug the leaking tubes. For the sake of time I will limit the scope of this presentation to include feedwater heaters and secondary system heat exchangers such as Hydrogen Coolers, Lube Oil Coolers, and nuclear Component Cooling Water, Emergency Cooling Water, Regenerative Heat Recovery heat exchangers.

  4. 40 CFR 63.654 - Heat exchange systems.

    Science.gov (United States)

    2010-07-01

    ... any one of the criteria in paragraphs (b)(1) through (2) of this section. (1) All heat exchangers that... any heat exchangers that are in organic HAP service as defined in this subpart). (c) The owner or... each heat exchanger exit line for each heat exchanger or group of heat exchangers in organic...

  5. 40 CFR 63.1409 - Heat exchange system provisions.

    Science.gov (United States)

    2010-07-01

    ... locations where the cooling water enters and exits each heat exchanger or any combination of heat exchangers.... (iii) For samples taken at the entrance and exit of each heat exchanger or any combination of heat exchangers, the entrance is the point at which the cooling water enters the individual heat exchanger...

  6. Synthesis of Heat Exchanger Network Considering Multipass Exchangers

    Institute of Scientific and Technical Information of China (English)

    李绍军; 姚平经

    2001-01-01

    Many methods have been proposed for synthesis of heat exchanger networks in recent years, most of which consider single pass exchangers. In this study some evolutionary rules have been proposed for synthesis of multipass exchanger networks. The method is based on the heuristic that optimal networks should feature maximum energy recovery and have the minimum number of shells. The effectiveness of the developed evolutionary rules is demonstrated through some literature examples.

  7. Analysis of a Flooded Heat Exchanger

    Science.gov (United States)

    Fink, Aaron H.; Luyben, William L.

    2015-01-01

    Flooded heat exchangers are often used in industry to reduce the required heat-transfer area and the size of utility control valves. These units involve a condensing vapor on the hot side that accumulates as a liquid phase in the lower part of the vessel. The heat transfer occurs mostly in the vapor space, but the condensate becomes somewhat…

  8. A Review on Heat Transfer Improvent of Plate Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Abhishek Nandan

    2015-03-01

    Full Text Available Plate heat exchanger has found a wide range of application in various industries like food industries, chemical industries, power plants etc. It reduces the wastage of energy and improves the overall efficiency of the system. Hence, it must be designed to obtain the maximum heat transfer possible. This paper is presented in order to study the various theories and results given over the improvement of heat transfer performance in a plate heat exchanger. However, there is still a lack in data and generalized equations for the calculation of different parameters in the heat exchanger. It requires more attention to find out various possible correlations and generalized solutions for the performance improvement of plate heat exchanger.

  9. REVIEW OF HEAT TRANSFER ENHANCEMENT IN DIFFERENT TYPES OF BAFFLES AND THEIR ORIENTATIONS.

    Directory of Open Access Journals (Sweden)

    S.P.WALDE

    2012-04-01

    Full Text Available The use of baffles in channel is commonly used for passive heat transfer enhancement strategy in single phase internal flow. Considering the rapid increase in energy demand, effective heat transfer enhancement techniques have become important task worldwide. Some of the applications of passive heat transfer enhancement strategies are in process industries, thermal regenerator, Shell and tube type heat exchanger, Internal cooling system of gas turbine blades, radiators for space vehicles and automobiles, etc. Thepresent paper is a review of different types of baffles and its arrangement. According to recent studies these are known to be economic heat transfer augmentation tools.

  10. Aplicación del Método de la Colonia de Hormigas Mixto a la optimización de intercambiadores de calor de tubo y coraza//Application of the Mixed Ant Colony Method to the optimization of tube and shell heat exchangers

    Directory of Open Access Journals (Sweden)

    Maida Bárbara Reyes‐Rodríguez

    2014-05-01

    Full Text Available Los procesos de transferencia de calor sonuno de los problemas más importantes a resolver en el campo de la Ingeniería. Entre los equipos más usados en la industria para realizar la transferencia de calor están los intercambiadores de calor de tubo y coraza. En el presente trabajo se desarrolla el procedimiento para la optimización del diseño de estos equipos utilizando el método de Kern y aplicando el algoritmo de la colonia de hormigas. Se aplica el mismo a tres ejemplos concretos y los resultados obtenidos se comparan con los obtenidos aplicando otros métodos de la inteligencia artificial. Se optimizan los principales parámetros geométricos de los intercambiadores de calor de tubo y coraza para lograr un menor costo de los mismos. Se demuestra la eficacia del nuevo procedimiento MACO (Mixed Ant Colony Optimization, en el proceso de optimización desde el punto de vista económico utilizando diferentes casos de estudios.Palabras claves: intercambiadores de calor, colonia de hormigas, método de Kern.______________________________________________________________________________AbstractHeat transfer processes are one of the most important problems to be solved in the field of Engineering. Among the most widely used equipment for heat transfer in the industry are the shell and tube heat exchangers. This paper develops the procedure for optimizing the design of shell and tube heat exchangers using the method of Kern and applying the ant colony algorithm. The procedure has been applied to three specific examples and the results obtained are compared with those obtained by applying other methods of artificial intelligence. The main geometric parameters of shell and tube heat exchangers are optimized, to achieve a lower cost of the exchanger. The efficacy of the new procedure MACO (Mixed Ant Colony Optimization for the optimization process from economically point of view was demonstrated, using different case studies.Key words: heat

  11. Comparison of heat transfer efficiency between heat pipe and tube bundles heat exchanger

    Directory of Open Access Journals (Sweden)

    Wu Zhao-Chun

    2015-01-01

    Full Text Available A comparison of heat transfer efficiency between the heat pipe and tube bundles heat exchanger is made based on heat transfer principle and the analysis of thermal characteristics. This paper argues that although heat pipe has the feature of high axial thermal conductivity, to those cases where this special function of heat transfer is unnecessary, heat pipe exchanger is not a high efficient heat exchanger when it is just used as a conventional heat exchanger in the industrial fields. In turn, there are some deficiencies for heat pipe exchanger, such as complicated manufacturing process, critical requirements for manufacturing materials, etc. which leads to a higher cost in comparison to a tubular heat exchanger. Nonetheless, due to its diverse structural features and extraordinary properties, heat pipe exchanger still has wide applications on special occasions.

  12. Research of Spined Heat-Exchanging Pipes

    Directory of Open Access Journals (Sweden)

    Akulov Kirill

    2016-01-01

    Full Text Available Work is devoted to a research of spined heat-exchanging pipes that are assumed to use in air-cooler exchangers (ACE. The proposed new geometry of finning allows intensifying heat exchange and improving the efficiency of air coolers. It is caused by the increased area of finned surface with a value of finning ratio (the ratio of the area of the smooth pipe to a finned one to 42.7, while in the commercially available ACE, the figure is 22. Besides, the geometrical arrangement of the pin fins turbulizes the airflow. It should be mentioned that an easier method of manufacturing of heat exchanging pipes is proposed to use, which will reduce their costs. The proposed heat exchange pipes are made by winding cut aluminum strip to the supporting pipe or stretching stamped blanks on it. To increase the efficiency of the heat exchange surface pin fins should be as thin and long as possible; however, their strength should be sufficient for deformation-free operation. Fins should be staggered to maximize the distance between them. Spined heat-exchange pipes are designed to operate in a commercially produced ACE and their service is carried out similarly to commercially produced transversely finned pipes.

  13. Mathematical Modeling of Spiral Heat Exchanger

    OpenAIRE

    Probal Guha , Vaishnavi Unde

    2014-01-01

    Compact Heat Exchangers (CHEs) are increasingly being used on small and medium scale industries. Due to their compact size and efficient design, they facilitate more efficient heat transfer. Better heat transfer would imply lesser fuel consumption for the operations of the plant, giving improvement to overall efficiency. This reduction in consumption of fuel is a step towards sustainable development. This report exclusively deals with the study the spiral heat ...

  14. Lightweight Thermal Storage Heat Exchangers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR proposal aims to develop thermal energy storage heat exchangers that are significantly lighter and higher conductance than the present art which involves...

  15. 在役列管换热器腐蚀的旋转超声检测%The Internal Rotary Inspection of the In-Service Tubular Heat Exchanger Corrosion

    Institute of Scientific and Technical Information of China (English)

    程东岳

    2015-01-01

    阐述了旋转超声检测系统(IRIS)的原理及特点,分析了运用该检测系统检测在役列管换热器管道腐蚀的工艺要点,探讨了安装调试方法及需要注意的问题,最后结合检测实践给出了具体测试方法。%This paper mainly describes the principles and characteristics of Internal Rotary Inspection System (IRIS), analyzes the technical points of evaluating the corrosion of shell and tube heat exchanger with IRIS,discusses the installation and debugging including the notice,and finally a measuring method from testing practice is introduced.

  16. Mathematical Modeling of Spiral Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Probal Guha , Vaishnavi Unde

    2014-04-01

    Full Text Available Compact Heat Exchangers (CHEs are increasingly being used on small and medium scale industries. Due to their compact size and efficient design, they facilitate more efficient heat transfer. Better heat transfer would imply lesser fuel consumption for the operations of the plant, giving improvement to overall efficiency. This reduction in consumption of fuel is a step towards sustainable development. This report exclusively deals with the study the spiral heat exchanger.The design considerations for spiral heat exchanger is that the flow within the spiral has been assumed as flow through a duct and by using Shah London empirical equation for Nusselt number design parameters are further optimized.This is accompanied by a detailed energy balance to generate a concise mathematical model

  17. Brayton-cycle heat exchanger technology program

    Science.gov (United States)

    Killackey, J. J.; Coombs, M. G.; Graves, R. F.; Morse, C. J.

    1976-01-01

    The following five tasks designed to advance this development of heat exchanger systems for close loop Brayton cycle power systems are presented: (1) heat transfer and pressure drop data for a finned tubular heat transfer matrix. The tubes are arranged in a triangular array with copper stainless steel laminate strips helically wound on the tubes to form a disk fin geometry; (2) the development of a modularized waste heat exchanger. Means to provide verified double containment are described; (3) the design, fabrication, and test of compact plate fin heat exchangers representative of full scale Brayton cycle recuperators; (4) the analysis and design of bellows suitable for operation at 1600 F and 200 psia for 1,000 cycles and 50,000 hours creep life; and (5) screening tests used to select a low cost braze alloy with the desirable attributes of a gold base alloy. A total of 22 different alloys were investigated; the final selection was Nicrobraz 30.

  18. 大管孔导流板管壳式换热器及其计算%Big Hole Baffle Tube and Shell Heat Exchanger Calculation

    Institute of Scientific and Technical Information of China (English)

    刘炳福

    2016-01-01

    管壳式换热器的折流板有圆缺形、碟环形等,使气体折流横过换热管流动,有其缺点。大管孔导流板是将这种板制作成一块整版,板上的管孔开大,叫大管孔导流板,即管孔直径比换热管直径大10%以上,让管隙流体全部导流从换热管外壁与大管孔的环隙间流过,使流体更趋向于紧贴换热管壁内外逆流传热。实践证明传热效果很好。还介绍了这种换热器传热系数和压力降的计算公式,很有实用价值。%shell and tube heat exchanger baffles have a moon-shaped,annular plate,so that the gas flow deflector across the heat exchange tubes,has its drawbacks.Big hole baffle plate is to make this into a full-page,open a large hole board,called the big hole deflector that pore diameter than the diameter of the heat transfer tubes more than 10% larger,so that tube gap all heat exchange fluid diversion from the outer ring with the big hole interstitial flow through the fluid tend to close the inner and outer countercurrent heat exchange tube has proved very good heat transfer effect.This also describes the formula coefficient of heat transfer and pressure drop, very practical value.

  19. Shell-side fluid flow and heat transfer in curved baffle heat exchanger%曲面弓形折流板换热器壳程流体流动与传热

    Institute of Scientific and Technical Information of China (English)

    钱才富; 高宏宇; 孙海阳

    2011-01-01

    提出一种新型折流板-曲面弓形折流板,并构造曲面弓形折流板换热器,采用数值模拟和实验相结合的方法研究其壳程传热和流动阻力性能.在实验方面,设计了实验用曲面弓形折流板和普通弓形折流板换热器试样,其中换热器管束采用可拆连接形式,以考察不同折流板结构和板间距的影响.通过改变管程及壳程流量和管程流体进口温度,获得了大量对应于不同折流板结构的壳程压力降和传热系数实验数据.在模拟方面,利用Fluent软件建立了曲面弓形折流板换热器和普通弓形折流板换热器流体数值分析模型,得到了壳程流体流场分布及壳程压力降和传热系数.结果发现,在相同结构参数和流动条件下,曲面弓形折流板换热器壳程压力降比普通弓形折流板换热器降低9 %~24%,而壳程传热系数比普通弓形折流板换热器提高3%~11%.%With reliable structure, mature design methodology and wide applications, shell-and-tube heat exchanger is the major form of heat exchange equipment and widely used in chemical, oil refining, power,food, medicine, aerospace and many other industries. In this study, a new type of baffle, namely curved baffle, is proposed and used to construct a shell-and-tube heat exchanger. Heat transfer and flow resistance of fluid in the shell side were studied numerically and experimentally. For the experiments, heat exchangers with curved baffles were designed and constructed, and the traditional heat exchanger with plane baffles was also made for comparison. Tube bundles in these heat exchangers are detachable for investigation of the effects of baffle structure and distance between them. By changing volumetric flow in the tube or shell-side and the inlet temperature of tube-side fluid, a large amount of experimental data about the pressure drop and heat transfer coefficient in the shell side were obtained for different baffle structures. For the simulation

  20. Heat transfer 1982; Proceedings of the Seventh International Conference, Technische Universitaet Muenchen, Munich, West Germany, September 6-10, 1982. Volume 6 - General papers: Combined heat and mass transfer, particle heat transfer, heat exchangers, industrial heat transfer, heat transfer in energy utilization

    Science.gov (United States)

    Grigull, U.; Hahne, E.; Stephan, K.; Straub, J.

    Laboratory and operational studies of heat transfer (HT) are presented. Such topics as the irreversibility of HT and mass transfer (MT), HT in disperse systems at high temperatures, fixed-bed reactors with submerged tube bundles, HT and MT in a low-speed turbulent boundary layer with condensation, multilayer insulation blankets for spacecraft applications, HT and MT in transpiration-cooled turbine blades, and finite-element analysis of HT in a solid with radiation and ablation are discussed. Contributions are included on the design of shell-and-tube heat exchangers to avoid flow-induced vibration, HT and MT in air-conditioning cooling coils, a friction-factor correlation for the offset strip-fin matrix, convective HT in gas-turbine combustion chambers, thermal-energy storage systems, turbulent buoyant HT in enclosures containing fire sources, a phase-change dry/wet cooling system for power plants, and the effect of secondary flow on HT in solar collector tubes. For individual items see A83-43014 to A83-43024

  1. Research of heat exchange rate of the pulsating heat pipe

    Directory of Open Access Journals (Sweden)

    Kravets V. Yu.

    2010-02-01

    Full Text Available Given article presents experimental research of heat transfer characteristics of the pulsating heat pipe (PHP which consists of seven coils with 1 mm inner diameter. Water was used as the heat carrier. PHP construction, measuring circuit and research technique are presented. It is shown that under PHP functioning there are two characteristic modes of operation, which can be distinguished by values of thermal resistance. PHP heat exchange features are disclosed.

  2. Observer-based monitoring of heat exchangers.

    Science.gov (United States)

    Astorga-Zaragoza, Carlos-Manuel; Alvarado-Martínez, Víctor-Manuel; Zavala-Río, Arturo; Méndez-Ocaña, Rafael-Maxim; Guerrero-Ramírez, Gerardo-Vicente

    2008-01-01

    The goal of this work is to provide a method for monitoring performance degradation in counter-flow double-pipe heat exchangers. The overall heat transfer coefficient is estimated by an adaptive observer and monitored in order to infer when the heat exchanger needs preventive or corrective maintenance. A simplified mathematical model is used to synthesize the adaptive observer and a more complex model is used for simulation. The reliability of the proposed method was demonstrated via numerical simulations and laboratory experiments with a bench-scale pilot plant.

  3. Phase Change Material Heat Exchanger Life Test

    Science.gov (United States)

    Lillibridge, Sean; Stephan, Ryan

    2009-01-01

    Low Lunar Orbit (LLO) poses unique thermal challenges for the orbiting space craft, particularly regarding the performance of the radiators. The IR environment of the space craft varies drastically from the light side to the dark side of the moon. The result is a situation where a radiator sized for the maximal heat load in the most adverse situation is subject to freezing on the dark side of the orbit. One solution to this problem is to implement Phase Change Material (PCM) Heat Exchangers. PCM Heat Exchangers act as a "thermal capacitor," storing thermal energy when there is too much being produced by the space craft to reject to space, and then feeding that energy back into the thermal loop when conditions are more favorable. Because they do not use an expendable resource, such as the feed water used by sublimators and evaporators, PCM Heat Exchangers are ideal for long duration LLO missions. In order to validate the performance of PCM Heat Exchangers, a life test is being conducted on four n-Pentadecane, carbon filament heat exchangers. Fluid loop performance, repeatability, and measurement of performance degradation over 2500 melt-freeze cycles will be performed.

  4. Near Field Investigation of Borehole Heat Exchangers

    OpenAIRE

    2015-01-01

    As an alternative and renewable energy source, the shallow geothermal energy evolving as one of the most popular energy source due to its easy accessibility and availability worldwide, and the ground source heat pump (GSHP) systems are the most frequent applications for extracting the energy from the shallow subsurface. As the heat extraction capacity of the GSHP system applications arises, the design of the borehole heat exchangers (BHE), which is the connected part of the system in the grou...

  5. Heat recovery equipment for engines

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C.L.

    1977-04-01

    The recovery and use of waste heat from prime movers is an important consideration for evaluating an on-site power system, since it is the basic factor that makes possible a substantial increase in fuel-use efficiency. The equipment usually employed to recover waste heat can be categorized as: (a) shell-and-tube type heat exchangers, (b) radiator-type heat exchangers, (c) exhaust gas boilers for the generation of pressurized hot water and/or steam, (d) steam separators, and (e) combined packaged units for ebulliently cooled internal combustion piston engines. The functional requirements and cost considerations involved in applying these devices for the recovery of waste heat from various types of prime-movers considered for application in the ICES Systems Engineering Program are examined.

  6. 斜向流换热器壳程流场均匀化研究%Research on Flow Field Homogenization in Shell Side of Sidelling Flow Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    古新; 王珂; 董其伍; 王永庆

    2012-01-01

    传统弓形折流板换热器壳程流体横向流动时存在流动阻力和传热死区大等缺点。为克服上述不足,研究开发了一种新型高效节能的斜向流管壳式换热器,采用导向型折流栅替代传统弓形折流板,倾斜流道内流体斜向冲刷换热管束。考察和对比了斜向流换热器和弓形折流板换热器壳程主流区的流体流速分布和变化规律,证实了导向型折流栅具有显著的控涡均化壳程流场和提高壳程流体整体流速的作用,有助于减小壳程压降,增大有效换热面积,为管壳式换热器结构改良提供了参考依据。%There are some disadvantages in the traditional segmental baffle heat exchanger for the transversal fluid flow in its shell side,such as the high flow resistance,large heat transfer dead region, and so on.For overcoming those above disadvantages,a kind of new efficient and energy saving shell-and-tube heat exchanger with sidelling flow in shell side is developed,the traditional segmental baffles are substituted by leading type shutter baffles,therefore,the fluid in some local regions flows over tubes inclinedly.The velocity distribution and velocity variation at the same position of main flow region in sidelling flow heat exchanger and segmental baffle heat exchanger is studied and compared.It is confirmed that,with the leading type shutter baffles in shell side,the vortex in shell side is weaken,flow field is greatly homogenized,and the velocity in shell side is increased.Shutter baffles are helpful to reduce the pressure drop in shell side and increase effective heat transfer area, which provides references for structure improving of shell-and-tube heat exchanger.

  7. 21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood...

  8. 40 CFR 63.104 - Heat exchange system requirements.

    Science.gov (United States)

    2010-07-01

    ... heat exchange system or at locations where the cooling water enters and exits each heat exchanger or any combination of heat exchangers. (i) For samples taken at the entrance and exit of recirculating... manufacturing process units. (iii) For samples taken at the entrance and exit of each heat exchanger or...

  9. Numerical study of heat transfer characteristics in BOG heat exchanger

    Science.gov (United States)

    Yan, Yan; Pfotenhauer, John M.; Miller, Franklin; Ni, Zhonghua; Zhi, Xiaoqin

    2016-12-01

    In this study, a numerical study of turbulent flow and the heat transfer process in a boil-off liquefied natural gas (BOG) heat exchanger was performed. Finite volume computational fluid dynamics and the k - ω based shear stress transport model were applied to simulate thermal flow of BOG and ethylene glycol in a full-sized 3D tubular heat exchanger. The simulation model has been validated and compared with the engineering specification data from its supplier. In order to investigate thermal characteristics of the heat exchanger, velocity, temperature, heat flux and thermal response were studied under different mass flowrates in the shell-side. The shell-side flow pattern is mostly determined by viscous forces, which lead to a small velocity and low temperature buffer area in the bottom-right corner of the heat exchanger. Changing the shell-side mass flowrate could result in different distributions of the shell-side flow. However, the distribution in the BOG will remain in a relatively stable pattern. Heat flux increases along with the shell-side mass flowrate, but the increase is not linear. The ratio of increased heat flux to the mass flow interval is superior at lower mass flow conditions, and the threshold mass flow for stable working conditions is defined as greater than 0.41 kg/s.

  10. RECITAL SCRUTINY ON TUBE-INTUBE COMPACT HEAT EXCHANGERS

    OpenAIRE

    V.NATARAJAN,; Dr. P. Senthil Kumar

    2011-01-01

    This paper focused on the investigational cram of the recital characteristics of tube-in-tube compact heat exchangers. Experiments are conducted in the compact heat exchangers with R-134a and liquefiedpetroleum gas. The effectiveness of the heat exchangers was calculated using the experiment data and it was found that the effectiveness of heat exchanger-1 is above 75 and heat exchanger-2 is above 84% for R-134a.The effectiveness of heat exchanger-1 is about 60% and heat exchanger-2 is about 8...

  11. Carbon nanotube heat-exchange systems

    Science.gov (United States)

    Hendricks, Terry Joseph; Heben, Michael J.

    2008-11-11

    A carbon nanotube heat-exchange system (10) and method for producing the same. One embodiment of the carbon nanotube heat-exchange system (10) comprises a microchannel structure (24) having an inlet end (30) and an outlet end (32), the inlet end (30) providing a cooling fluid into the microchannel structure (24) and the outlet end (32) discharging the cooling fluid from the microchannel structure (24). At least one flow path (28) is defined in the microchannel structure (24), fluidically connecting the inlet end (30) to the outlet end (32) of the microchannel structure (24). A carbon nanotube structure (26) is provided in thermal contact with the microchannel structure (24), the carbon nanotube structure (26) receiving heat from the cooling fluid in the microchannel structure (24) and dissipating the heat into an external medium (19).

  12. VENTILATION SYSTEM WITH GROUND HEAT EXCHANGER

    Directory of Open Access Journals (Sweden)

    Vyacheslav Pisarev

    2016-11-01

    Full Text Available Ventilation systems consume more and more energy because of the often complex treatment of the air supplied to closed spaces. Looking for sources of energy allow for significant savings costs, which often translate into renewable energy sources. One of the more popular solutions is to use energy from the ground by various methods. Known and relatively common solutions are based on ground heat exchanger and ground collector cooperating with a heat pump. The paper presents the possibility of cooperation ventilation system with ground air heat exchanger and heat pump both in summer and winter period. A number solutions of this type of system, supported by calculation examples and moist air transformation in the Moliere chart have been presented. Support ventilation system with renewable energy sources allows significant savings in operating as shown in the article.

  13. Modelling Heat Exchangers for Domestic Boilers

    Directory of Open Access Journals (Sweden)

    S. F. C. F. Teixeira

    2000-01-01

    Full Text Available In the present paper the thermal behaviour of fin-tube heat exchangers is modeled. Particular attention has been given to the plate fins. The heat fluxes in the fins are described using a finite volume technique to discretize the energy equation. The thermal interactions with the water in the tubes and the surrounding air are treated as external boundaries, using appropriate relationships for forced convection in pipes and flat plates. The numerical results are presented in terms of dimensionless numbers (Fourier, Biot and geometric ratios which are found to be representative for this particular geometry. Furthermore, the effect of thermal gradients along the fin surface upon the fin efficiency is investigated. Based on a differential model for the heat balances, design charts have been developed for the thermal analysis of heat exchangers.

  14. Fluid Flow and Heat Transfer Properties in Shell-side of New Heat Exchanger%新型热交换器壳程流体流动与传热特性

    Institute of Scientific and Technical Information of China (English)

    刘延斌; 王学生; 简林均; 张崇; 王建甫

    2013-01-01

    An experimental study on the shell side flow and heat transfer of a new type shell and tube heat exchanger was conducted ,and comparative research of a segmental baffle heat exchang‐er with the same specifications was made .Then simplified shell side computational models of the two heat exchangers were created for numerical simulation ,temperature ,flow and pressure dis‐tributions were obtained ,and the simulation results were compared with the experimental data . Experimental study and numerical simulation results show :the new longitudinal‐flow heat ex‐changer has uniform temperature distribution ,small flow dead zone ,low shell pressure drop ,and combination property is much higher than segmental baffle heat exchanger .%  完成了新型热交换器的传热与流动性能实验研究,并与同规格下的弓形折流板热交换器性能进行对比。建立了简化的壳程计算模型,分别对弓形折流板热交换器和新型纵流式热交换器进行数值模拟,获得了2种热交换器壳程内部的流动分布、温度分布和压力分布,并将模拟结果与实验数据进行了对比。实验及模拟结果表明,新型热交换器温度分布均匀、流动死区少、壳程压降低,综合性能远高于折流板式热交换器。

  15. 14 CFR 29.1125 - Exhaust heat exchangers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Exhaust heat exchangers. 29.1125 Section 29... exchangers. For reciprocating engine powered rotorcraft the following apply: (a) Each exhaust heat exchanger... is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff may have...

  16. 14 CFR 25.1125 - Exhaust heat exchangers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Exhaust heat exchangers. 25.1125 Section 25... exchangers. For reciprocating engine powered airplanes, the following apply: (a) Each exhaust heat exchanger... provisions wherever it is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or...

  17. Exergy-Economic Criteria for Evaluating Heat Exchanger Performance

    Institute of Scientific and Technical Information of China (English)

    Wu Shuangying; Li Yourong

    2001-01-01

    Based on the exergy-economic analysis of heat exchanger heat transfer and flow process, two new exergyeconomic criteria which are defined as the total costs per unit heat transfer rate ηt t for heat transfer exchanger and the net profit per unit heat recovery rate ηr for heat recovery exchanger respectively are put forward.Furthermore, the application of criteria is illustrated by the evaluation of down-flow, counter-flow and cross-flow heat exchangers performance. The methods employed and results presented in this paper can serve as a guide for the performance evaluation of heat exchangers.

  18. Weld manufacturing of big heat-exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Braeutigam, M.; Huppertz, P.H.

    1986-06-24

    The topic of this article are big heat exchangers, which are developed and constructed to minimize energy losses in plants of process engineering. Some welding specifications are discussed in detail. Some constructive details, as e.g. materials selection and vibration safety complete this contribution.

  19. Measurement of heat and moisture exchanger efficiency.

    Science.gov (United States)

    Chandler, M

    2013-09-01

    Deciding between a passive heat and moisture exchanger or active humidification depends upon the level of humidification that either will deliver. Published international standards dictate that active humidifiers should deliver a minimum humidity of 33 mg.l(-1); however, no such requirement exists, for heat and moisture exchangers. Anaesthetists instead have to rely on information provided by manufacturers, which may not allow comparison of different devices and their clinical effectiveness. I suggest that measurement of humidification efficiency, being the percentage moisture returned and determined by measuring the temperature of the respired gases, should be mandated, and report a modification of the standard method that will allow this to be easily measured. In this study, different types of heat and moisture exchangers for adults, children and patients with a tracheostomy were tested. Adult and paediatric models lost between 6.5 mg.l(-1) and 8.5 mg.l(-1) moisture (corresponding to an efficiency of around 80%); however, the models designed for patients with a tracheostomy lost between 16 mg.l(-1) and 18 mg.l(-1) (60% efficiency). I propose that all heat and moisture exchangers should be tested in this manner and percentage efficiency reported to allow an informed choice between different types and models.

  20. Exergo-ecological evaluation of heat exchanger

    Directory of Open Access Journals (Sweden)

    Stanek Wojciech

    2014-01-01

    Full Text Available Thermodynamic optimization of thermal devices requires information about the influence of operational and structural parameters on its behaviour. The interconnections among parameters can be estimated by tools such as CFD, experimental statistic of the deviceetc. Despite precise and comprehensive results obtained by CFD, the time of computations is relatively long. This disadvantage often cannot be accepted in case of optimization as well as online control of thermal devices. As opposed to CFD the neural network or regression is characterized by short computational time, but does not take into account any physical phenomena occurring in the considered process. The CFD model of heat exchanger was built using commercial package Fluent/Ansys. The empirical model of heat exchanger has been assessed by regression and neural networks based on the set of pseudo-measurements generated by the exact CFD model. In the paper, the usage of the developed empirical model of heat exchanger for the minimisation of TEC is presented. The optimisationconcerns operational parameters of heat exchanger. The TEC expresses the cumulative exergy consumption of non-renewable resources. The minimization of the TEC is based on the objective function formulated by Szargut. However, the authors extended the classical TEC by the introduction of the exergy bonus theory proposed by Valero. The TEC objective function fulfils the rules of life cycle analysis because it contains the investment expenditures (measured by the cumulative exergy consumption of non-renewable natural resources, the operation of devices and the final effects of decommissioning the installation.

  1. Feedback linearisation of a heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, M.H.R.F.; Devanathan, R. Sr. [Nanyang Technological Univ. (Singapore)

    1994-12-31

    The main contribution of the paper is to provide an explicit necessary and sufficient conditions for the system to be locally linearisable in terms of parameters of the heat exchanger model. Examples illustrate how the controllability issues which are standard in linear system theory can be naturally extended to the nonlinear system model via the linearising transformation.

  2. Optimization of Borehole Heat Exchanger Arrays

    Science.gov (United States)

    Schulte, Daniel; Rühaak, Wolfram; Welsch, Bastian; Oladyshkin, Sergey; Sass, Ingo

    2016-04-01

    Arrays of borehole heat exchangers are an increasingly popular source for renewable energy. Furthermore, they can serve as borehole thermal energy storages for seasonally fluctuating heat sources like solar thermal energy or district heating grids. However, the uncertainty of geological parameters and the nonlinear behavior of the complex system make it difficult to simulate and predict the required design of borehole heat exchanger arrays. As a result, the arrays easily turn out to be over or undersized, which compromises the economic feasibility of these systems. Here, we present a novel optimization strategy for the design of borehole thermal energy storages. The arbitrary polynomial chaos expansion method is used to build a proxy model from a set of numerical training simulations, which allows for the consideration of parameter uncertainties. Thus, the resulting proxy model bypasses the problem of excessive computation time for the numerous function calls required for a mathematical optimization. Additionally, we iteratively refine the proxy model during the optimization procedure using additional numerical simulation runs. With the presented solution, many aspects of borehole heat exchanger arrays can be optimized under geological uncertainty.

  3. Heat Transfer of Nanofluid in a Double Pipe Heat Exchanger.

    Science.gov (United States)

    Aghayari, Reza; Maddah, Heydar; Zarei, Malihe; Dehghani, Mehdi; Kaskari Mahalle, Sahar Ghanbari

    2014-01-01

    This paper investigates the enhancement of heat transfer coefficient and Nusselt number of a nanofluid containing nanoparticles (γ-AL2O3) with a particle size of 20 nm and volume fraction of 0.1%-0.3% (V/V). Effects of temperature and concentration of nanoparticles on Nusselt number changes and heat transfer coefficient in a double pipe heat exchanger with counter turbulent flow are investigated. Comparison of experimental results with valid theoretical data based on semiempirical equations shows an acceptable agreement. Experimental results show a considerable increase in heat transfer coefficient and Nusselt number up to 19%-24%, respectively. Also, it has been observed that the heat transfer coefficient increases with the operating temperature and concentration of nanoparticles.

  4. RECITAL SCRUTINY ON TUBE-INTUBE COMPACT HEAT EXCHANGERS

    Directory of Open Access Journals (Sweden)

    V.NATARAJAN,

    2011-04-01

    Full Text Available This paper focused on the investigational cram of the recital characteristics of tube-in-tube compact heat exchangers. Experiments are conducted in the compact heat exchangers with R-134a and liquefiedpetroleum gas. The effectiveness of the heat exchangers was calculated using the experiment data and it was found that the effectiveness of heat exchanger-1 is above 75 and heat exchanger-2 is above 84% for R-134a.The effectiveness of heat exchanger-1 is about 60% and heat exchanger-2 is about 81% for liquefied petroleum gas. In this paper, details about the new tube-in-tube type compact heat exchanger, experimental setup, results and conclusions are discussed.

  5. Performance Investigation of Plate Type Heat Exchanger (A Case Study

    Directory of Open Access Journals (Sweden)

    Simarpreet Singh

    2014-04-01

    Full Text Available Heat exchanger is a thermodynamic system which is most commonly used in the process industry for exchanging heat energy between the fluids. flowing in the same or opposite direction. It is desired that effectiveness of heat exchanger should remain as large as possible. Heat exchanger's performance may be improved by the addition of fins or corrugations. These investigations include design of plate type heat exchanger, heat transfer enhancement, flow phenomenon and cleanliness factor. In process plants, this type of heat exchange is generally used for recovering heat content of exhaust steam. However, with the flow of fluid for a long period, fouling occurs on the plate surface. Therefore, it is required to investigate the effect of fouling, wherever the heat exchanger is installed. An extensive experimental investigation has been carried out under clean and dirty condition of the said plate type heat exchanger. Heat transfer and flow data were collected in experiment. From collected data heat transfer rate, overall heat transfer coefficient, fouling factor and cleanliness factor were evaluated. Based upon the cleanliness factor data, next date of cleanliness for plate type heat exchanger was predicted. It is felt that the outcome of the present research work may be quite useful for efficient operation of plate type heat exchanger installed in Process plants.

  6. 14 CFR 23.1125 - Exhaust heat exchangers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Exhaust heat exchangers. 23.1125 Section 23... § 23.1125 Exhaust heat exchangers. For reciprocating engine powered airplanes the following apply: (a) Each exhaust heat exchanger must be constructed and installed to withstand the vibration, inertia,...

  7. 40 CFR 63.1435 - Heat exchanger provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Heat exchanger provisions. 63.1435... Standards for Hazardous Air Pollutant Emissions for Polyether Polyols Production § 63.1435 Heat exchanger... for heat exchange systems, with the exceptions noted in paragraphs (b) through (e) of this section....

  8. A heat transfer model of a horizontal ground heat exchanger

    Science.gov (United States)

    Mironov, R. E.; Shtern, Yu. I.; Shtern, M. Yu.; Rogachev, M. S.

    2016-04-01

    Ground-source heat pumps are gaining popularity in Eastern Europe, especially those which are using the horizontal ground heat exchanger (GHX). Due to the difficulty of accessing GHX after the installation, materials and the quality of the installation must satisfy the very high requirements. An inaccurate calculation of GHX can be the reason of a scarcity of heat power in a crucial moment. So far, there isn't any appropriate mathematical description of the horizontal GHX which takes into account the mutual influence of GHX pipes on each other. To solve this problem we used the temperature wave approach. As a result, a mathematical model which describes the dependence of the heat transfer rate per unit length of the horizontal GHX pipe on the thermal properties of soil, operating time of GHX and the distance between pipes was obtained. Using this model, heat transfer rates per unit length of a horizontal GHX were plotted as functions of the distance between pipes and operating time. The modeling shows that heat transfer rates decreases rapidly with the distance between pipes lower then 2 meters. After the launch of heat pump, heat power of GHX is reduced during the first 20 - 30 days and get steady after that. The obtained results correlate with experimental data. Therefore the proposed mathematical model can be used to design a horizontal GHX with the optimal characteristics, and predict its capability during operation.

  9. The Conduction of Heat through Cryogenic Regenerative Heat Exchangers

    Science.gov (United States)

    Superczynski, W. F.; Green, G. F.

    2006-04-01

    The need for improved regenerative cryocooler efficiency may require the replacement of conventional matrices with ducts. The ducts can not be continuous in the direction of temperature gradient when using conventional materials to prevent unacceptable conduction losses. However, this discontinuity creates a complex geometry to model and determine conduction losses. Chesapeake Cryogenics, Inc. has designed, fabricated and tested an apparatus for measuring the heat conduction through regenerative heat exchangers implementing different matrices. Data is presented for stainless steel photo etched disk, phophorus-bronze embossed ribbon coils and screens made of both stainless steel and phosphorus-bronze. The heat conduction was measured with the regenerators evacuated and pressurized with helium gas. In this test apparatus, helium gas presence increased the heat leak significantly. A description of the test apparatus, instrumentation, experimental methods and data analysis are presented.

  10. Heat exchanger life extension via in-situ reconditioning

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, David E.; Muralidharan, Govindarajan

    2016-06-28

    A method of in-situ reconditioning a heat exchanger includes the steps of: providing an in-service heat exchanger comprising a precipitate-strengthened alloy wherein at least one mechanical property of the heat exchanger is degraded by coarsening of the precipitate, the in-service heat exchanger containing a molten salt working heat exchange fluid; deactivating the heat exchanger from service in-situ; in a solution-annealing step, in-situ heating the heat exchanger and molten salt working heat exchange fluid contained therein to a temperature and for a time period sufficient to dissolve the coarsened precipitate; in a quenching step, flowing the molten salt working heat-exchange fluid through the heat exchanger in-situ to cool the alloy and retain a supersaturated solid solution while preventing formation of large precipitates; and in an aging step, further varying the temperature of the flowing molten salt working heat-exchange fluid to re-precipitate the dissolved precipitate.

  11. Microchannel Heat Exchangers with Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y.; Ohadi, M.M.; Radermacher, R.

    2001-09-15

    The objective of the present study was to determine the performance of CO{sub 2} microchannel evaporators and gas coolers in operational conditions representing those of residential heat pumps. A set of breadboard prototype microchannel evaporators and gas coolers was developed and tested. The refrigerant in the heat exchangers followed a counter cross-flow path with respect to the airflow direction. The test conditions corresponded to the typical operating conditions of residential heat pumps. In addition, a second set of commercial microchannel evaporators and gas coolers was tested for a less comprehensive range of operating conditions. The test results were reduced and a comprehensive data analysis, including comparison with the previous studies in this field, was performed. Capacity and pressure drop of the evaporator and gas cooler for the range of parameters studied were analyzed and are documented in this report. A gas cooler performance prediction model based on non-dimensional parameters was also developed and results are discussed as well. In addition, in the present study, experiments were conducted to evaluate capacities and pressure drops for sub-critical CO{sub 2} flow boiling and transcritical CO{sub 2} gas cooling in microchannel heat exchangers. An extensive review of the literature failed to indicate any previous systematic study in this area, suggesting a lack of fundamental understanding of the phenomena and a lack of comprehensive data that would quantify the performance potential of CO{sub 2} microchannel heat exchangers for the application at hand. All experimental tests were successfully conducted with an energy balance within {+-}3%. The only exceptions to this were experiments at very low saturation temperatures (-23 C), where energy balances were as high as 10%. In the case of evaporators, it was found that a lower saturation temperature (especially when moisture condensation occurs) improves the overall heat transfer coefficient

  12. Characteristics of heat flow in recuperative heat exchangers

    Directory of Open Access Journals (Sweden)

    Lalović Milisav

    2005-01-01

    Full Text Available A simplified model of heat flow in cross-flow tube recuperative heat exchangers (recuperators was presented in this paper. One of the purposes of this investigation was to analyze changes in the values of some parameters of heat transfer in recuperators during combustion air preheating. The logarithmic mean temperature (Atm and overall heat transfer coefficient (U, are two basic parameters of heat flow, while the total heated area surface (A is assumed to be constant. The results, presented as graphs and in the form of mathematical expressions, were obtained by analytical methods and using experimental data. The conditions of gaseous fuel combustions were defined by the heat value of gaseous fuel Qd = 9263.894 J.m-3, excess air ratio λ= 1.10, content of oxygen in combustion air ν(O2 = 26%Vol, the preheating temperature of combustion air (cold fluid outlet temperature tco = 100-500°C, the inlet temperature of combustion products (hot fluid inlet temperature thi = 600-1100°C.

  13. Technology Solutions Case Study: Foundation Heat Exchanger, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-03-01

    The foundation heat exchanger, developed by Oak Ridge National Laboratory, is a new concept for a cost-effective horizontal ground heat exchanger that can be connected to water-to-water or water-to-air heat pump systems for space conditioning as well as domestic water heating.

  14. Investigation Status of Heat Exchange while Boiling Hydrocarbon Fuel

    Directory of Open Access Journals (Sweden)

    D. S. Obukhov

    2006-01-01

    Full Text Available The paper contains analysis of heat exchange investigations while boiling hydrocarbon fuel. The obtained data are within the limits of the S.S. Kutateladze dependence proposed in 1939. Heat exchange at non-stationary heat release has not been investigated. The data for hydrocarbon fuel with respect to critical density of heat flow are not available even for stationary conditions.

  15. Development of Submersible Corrugated Pipe Sewage Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    BAI Li; SHI Yan; TAN Yu-fei

    2009-01-01

    Based on the characteristics of heat transfer for corrugated pipe,a method of calculating and de-sign on the submersible corrugated pipe sewage heat exchanger was put forward theoretically and experimental-ly.The actual movement parameters of air-conditioning system used in this heat exchanger were measured.The experimental result shows that the quantity of heat transfer of the corrugated pipe sewage heat exchanger can satisfy the building's load with the average coefficient of performance 4.55.At the same time.the quantity ot heat transfer of the corrugated pipe sewage heat exchanger was compared with that of the other nonmetallic sewage heat exchangers(i.e.,the plastic-Al pipe sewage heat exchanger and PP-R pipe sewage heat exchanger)experimentally.It is found out that the effect of heat transfer for submersible corrugated pipe sewage heat ex-changer is superior to those of the plastic-Al pipe and the PP-R pipe.The quantity of heat transfer per mile of corrugated pipe sewage heat exchanger is 5.2 times as much as that of the plastic-Al pipe,and it is 8.1 times as much as that of PP-R pipe.

  16. Analytical and experimental analysis of tube coil heat exchanger

    Science.gov (United States)

    Smusz, R.

    2016-09-01

    The paper presents the analytical and experimental analysis of heat transfer for the finned tube coil heat exchanger immersed in thermal storage tank. The tank is equipped with three helical-shaped heating coils and cylindrical- shaped stratification device. Two coils, upper and lower, use the water as a heating medium. The third, double wall heat exchanger coil, located at the bottom head on the tank is filled by the refrigerant (freon). Calculations of thermal power of water coil were made. Correlations of heat transfer coefficients in curved tubes were applied. In order to verify the analytical calculations the experimental studies of heat transfer characteristic for coil heat exchanger were performed.

  17. AUTOMATIC EVOLUTION OF HEAT EXCHANGER NETWORKS WITH SIMULTANEOUS HEAT EXCHANGER DESIGN

    Directory of Open Access Journals (Sweden)

    F.S. LIPORACE

    1999-03-01

    Full Text Available Recently, a new software (AtHENS that automatically synthesizes a heat exchanger network with minima consumption of utilities was developed. This work deals with the next step, which represents the evolution of the initial network. Hence, new procedures to identify and break loops are incorporated, for which a new algorithm is proposed. Also, a heat exchanger design procedure which uses the available pressure drop to determine the film coefficient on the tube side and shell side is added, providing the utilization of more realistic heat exchangers in the network during its optimization. Results obtained from a case study point to the possibility of equipment design having a strong influence on the network synthesis.

  18. Automatic evolution of heat exchanger networks with simultaneous heat exchanger design

    Energy Technology Data Exchange (ETDEWEB)

    Liporace, F.S.; Pessoa, F.L.P.; Queiroz, E.M. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica. Dept. de Engenharia Quimica]. E-mail: lipo@h2o.eq.ufrj.br; lipo@hexanet.com.br

    1999-03-01

    Recently, a new software (AtHENS) that automatically synthesizes a heat exchanger network with minima consumption of utilities was developed. This work deals with the next step, which represents the evolution of the initial network. Hence, new procedures to identify and break loops are incorporated, for which a new algorithm is proposed. Also, a heat exchanger design procedure which uses the available pressure drop to determine the film coefficient on the tube side and shell side is added, providing the utilization of more realistic heat exchangers in the network during its optimization. Results obtained from a case study point to the possibility of equipment design having a strong influence on the network synthesis. (author)

  19. Expanded microchannel heat exchanger: design, fabrication and preliminary experimental test

    CERN Document Server

    Denkenberger, David C; Pearce, Joshua M; Zhai, John; 10.1177/0957650912442781

    2012-01-01

    This paper first reviews non-traditional heat exchanger geometry, laser welding, practical issues with microchannel heat exchangers, and high effectiveness heat exchangers. Existing microchannel heat exchangers have low material costs, but high manufacturing costs. This paper presents a new expanded microchannel heat exchanger design and accompanying continuous manufacturing technique for potential low-cost production. Polymer heat exchangers have the potential for high effectiveness. The paper discusses one possible joining method - a new type of laser welding named "forward conduction welding," used to fabricate the prototype. The expanded heat exchanger has the potential to have counter-flow, cross-flow, or parallel-flow configurations, be used for all types of fluids, and be made of polymers, metals, or polymer-ceramic precursors. The cost and ineffectiveness reduction may be an order of magnitude or more, saving a large fraction of primary energy. The measured effectiveness of the prototype with 28 micro...

  20. 基于SolidWorks Flow Simulation的管壳式换热器传热性能数值仿真%Numerical simulation of heat transfer performance of shell-and-tube heat exchanger based on SolidWorks Flow Simulation

    Institute of Scientific and Technical Information of China (English)

    曹茹; 商跃进

    2015-01-01

    为了分析结构形式和流动状态等因素对换热器传热效果的影响,以单根圆管换热器为研究对象验证了SolidWorks Flow Simulation软件进行仿真分析的可行性.基于该软件分析了流动形式和扁管厚度对扁管换热器传热性能的影响,并拟合了扁管沿程摩擦阻力系数计算公式.研究结果表明,数值模拟方法有效,扁管沿程摩擦阻力系数计算公式具有一定的参考价值.

  1. 导向型折流栅强化换热器壳程传热的数值模拟%Numerical Simulation on Heat Transfer Enhancement in Shell Side of Shell-and-Tube Heat Exchanger with Leading Type Shutter Baffles

    Institute of Scientific and Technical Information of China (English)

    古新; 董其伍; 刘敏珊; 周雅宁

    2010-01-01

    提出壳程流体"斜向流"的新概念,解决了管壳式换热器性能提升的同时伴随流体流动阻力大幅增加的矛盾.研制了具有导向型折流栅管束支撑结构的新型高效节能斜向流管壳式换热器.采用场协同理论分析该换热器的强化传热机理,证明在此类换热器壳程中流体速度场与温度梯度场具有良好的协同关系.数值模拟了几何结构对传热和压降的影响规律,模拟结果与实验数据吻合良好.

  2. THREE-DIMENSIONAL NUMERICAL SIMULATION OF TURBULENT FLOW AND HEAT TRANSFER CHARACTERISTICS IN SHELL SIDE OF SHELL-AND -TUBE HEAT EXCHANGERS%管壳式换热器壳侧湍流流动与换热的三维数值模拟

    Institute of Scientific and Technical Information of China (English)

    邓斌; 陶文铨

    2004-01-01

    综合应用体积多孔度、表面渗透度和分布阻力方法建立了适用于准连续介质的N-S修正控制方程.用改进的k-ε模型考虑管束对湍流的产生和耗散的影响,用壁面函数法处理壳壁和折流板的壁面效应, 对一管壳式换热器的壳侧湍流流动与换热进行了三维数值模拟.对计算结果进行了归纳,并与换热器冷态实验、前人的研究结果进行了对比分析,从而证明了该方法能更有效地模拟管壳式换热器壳侧的流动特性,压降实验数据和计算结果符合良好.

  3. 国标板管间隙对流动与传热的细观影响研究%Study of the Microscopic Influence of the Tubesheet/Tube Clearance Stipulated by the National Standard on the Flow and Heat Transfer in a Shell and Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    董其伍; 欧阳克; 刘敏珊; 张丽娜

    2011-01-01

    为了研究国标中规定的板管间隙对管壳式换热器壳程流动与传热的细现影响,运用CFD软件建立管壳式换热器壳程周期模型并进行了数值计算.分析结果表明,当板管间隙小于等于国标Ⅰ级管束规定的最大间隙0.35 mm时,间隙漏流影响的范围很小,折流板之间流体的流动趋近于理想横流,传热效果好;当间隙大于等于国标Ⅱ级管束规定的最大间隙0.5 mm时,漏流产生的漩涡强度变大,折流板之间流体的流动趋近于纵向流,从而导致换热管的整体传热性能下降;在折流板背面存在一个换热性能最差的截面,该截面与折流板之间的距离随着船和间隙的增大而增大.

  4. 管壳式换热器新型管支撑结构在传热强化方面的进展%The Developments on Heat Transfer Enhancement in The New Pattern Baffle of Shell-and-Tube Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    陈姝; 高学农; 徐娓; 王端阳

    2006-01-01

    本文讨论了管壳式换热器新型管支撑结构在强化传热方面所取得的一些进展、传热机理及应用范围,并简介了CFD技术同管壳式换热器结合研究的情况,提出将几种强化技术和计算机辅助设计手段结合起来是将来换热器的发展方向.

  5. Oxidizer heat exchangers for rocket engine operation in idle modes

    Science.gov (United States)

    Kanic, P. G.; Kmiec, T. D.

    1987-01-01

    The heat exchanger concept is discussed together with its role in rocket engine operation in idle modes. Two heat exchanger designs (low and high heat transfer) utilizing different approaches to achieve stable oxygen vaporization are presented as well as their performance test results. It is concluded that compact and lightweight heat exchangers can be used in a stable manner under the 'idle' operating conditions expected with the RL10 rocket engine.

  6. Complex Heat Exchangers for Improved Performance

    Science.gov (United States)

    Bran, Gabriela Alejandra

    After a detailed literature review, it was determined that there was a need for a more comprehensive study on the transient behavior of heat exchangers. Computational power was not readily available when most of the work on transient heat exchangers was done (1956 - 1986), so most of these solutions have restrictions, or very specific assumptions. More recently, authors have obtained numerical solutions for more general problems (2003 - 2013), but they have investigated very specific conditions, and cases. For a more complex heat exchanger (i.e. with heat generation), the transient solutions from literature are no longer valid. There was a need to develop a numerical model that relaxes the restrictions of current solutions to explore conditions that have not been explored. A one dimensional transient heat exchanger model was developed. There are no restrictions on the fluids and wall conditions. The model is able to obtain a numerical solution for a wide range of fluid properties and mass flow rates. Another innovative characteristic of the numerical model is that the boundary and initial conditions are not limited to constant values. The boundary conditions can be a function of time (i.e. sinusoidal signal), and the initial conditions can be a function of position. Four different cases were explored in this work. In the first case, the start-up of a system was investigated where the whole system is assumed to be at the same temperature. In the second case, the new steady state in case one gets disrupted by a smaller inlet temperature step change. In the third case, the new steady state in case one gets disrupted by a step change in one of the mass flow rates. The response of these three cases show that there are different transient behaviors, and they depend on the conditions imposed on the system. The fourth case is a system that has a sinusoidal time varying inlet temperature for one of the flows. The results show that the sinusoidal behavior at the inlet

  7. Simulation Studies on A Cross Flow Plate Fin Heat Exchanger

    Directory of Open Access Journals (Sweden)

    M. Thirumarimurugan

    2008-01-01

    Full Text Available Compact heat exchangers which were initially developed for the aerospace industries in the1940s have been considerably improved in the past few years. The main reasons for the goodperformance of compact heat exchangers are their special design which includes turbulent which inturn use high heat transfer coefficient and resists fouling, and maximum temperature driving forcebetween the hot and cold fluids. Numerous types use special enhancement techniques to achieve therequired heat transfer in smaller plot areas and, in many cases, less initial investment. One such type ofcompact heat exchanger is the Plate-fin heat exchanger. The complexity of compact heat exchangerdesign equations results from the exchangers unique ability to transfer heat between multiple processstreams and a wide array of possible flow configurations. This paper presents the performanceevaluation of cross flow plate fin heat exchanger with several different Gas-Liquid systems.Experimental results such as exchanger effectiveness, overall heat transfer coefficients were calculatedfor the flow systems of Cross flow Heat Exchangers. A steady state model for the outlet temperature ofboth the cold and hot fluid and overall heat transfer coefficient of a plate-fin cross flow heat exchangerwas developed and simulated using MATLAB, which was verified with the experiments conducted.

  8. BASIMO - Borehole Heat Exchanger Array Simulation and Optimization Tool

    Science.gov (United States)

    Schulte, Daniel; Rühaak, Wolfram; Welsch, Bastian; Bär, Kristian; Sass, Ingo

    2016-04-01

    Borehole heat exchangers represent a well-established technology, which pushes for new fields of applications and novel modifications. Current simulation tools cannot - or only to some extent - describe features like inclined or partly insulated boreholes unless they run fully discretized models of the borehole heat exchangers. However, fully discretized models often come at a high computational cost, especially for large arrays of borehole heat exchangers. We present a tool, which uses one dimensional thermal resistance and capacity models for the borehole heat exchangers coupled with a numerical finite element model for the subsurface heat transport. An unstructured tetrahedral mesh bypasses the limitations of structured grids for borehole path geometries, while the thermal resistance and capacity model is improved to account for borehole heat exchanger properties changing with depth. The presented tool benefits from the fast analytical solution of the thermal interactions within the boreholes while still allowing for a detailed consideration of the borehole heat exchanger properties.

  9. Optimization of the Single Staggered Wire and Tube Heat Exchanger

    OpenAIRE

    Arsana I Made; Susianto; Budhikarjono Kusno; Altway Ali

    2016-01-01

    Wire and tube heat exchanger consists of a coiled tube, and wire is welded on the two sides of it in normal direction of the tube. Generally,wire and tube heat exchanger uses inline wire arrangement between the two sides, whereas in this study, it used staggered wire arrangement that reduces the restriction of convection heat transfer. This study performed the optimization of single staggered wire and tube heat exchanger to increase the capacity and reduce the mass of the heat exchanger. Opti...

  10. Shell-and-double concentric-tube heat exchangers

    Science.gov (United States)

    Bougriou, Chérif; Baadache, Khireddine

    2010-03-01

    This study concerns a new type of heat exchangers, which is that of shell-and-double concentric-tube heat exchangers. These heat exchangers can be used in many specific applications such as air conditioning, waste heat recovery, chemical processing, pharmaceutical industries, power production, transport, distillation, food processing, cryogenics, etc. The case studies include both design calculations and performance calculations. It is demonstrated that the relative diameter sizes of the two tubes with respect to each other are the most important parameters that influence the heat exchanger size.

  11. Development and benefits of air/air-heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Kessel, H.W.; Cremer, P.

    1986-02-01

    After the first experiments using glass tube heat exchangers, many air/air heat exchangers have made within ten years the breakthrough as ''interior climate improvers'' in stables. Especially inexpensive synthetic panels, foils and self-construction, ribbed heat exchangers are very popular among farmers. Based on thorough installation planning and satisfactory operating results, thousands of heat exchangers were installed, through which heating oil and fuel gas are being replaced as energy sources, and through an improved interior climate, the productivity can be optimized in fattening and rearing houses. (orig.).

  12. Research on ground heat exchanger of Ground Source Heat Pump technique

    Institute of Scientific and Technical Information of China (English)

    LIU Dong-sheng; SUN You-hong; GAO Ke; WU Xiao-hang

    2004-01-01

    Ground Source Heat Pump technique and its operating principle are described in this paper. Ground heat exchanger is the key technique of ground source heat pump and its pattems are discussed. Software is helpful to design ground heat exchanger. A project of Chinese Ground Source Heat Pump is introduced and its market is more and more extensive.

  13. Experimental investigation of heat transfer and effectiveness in corrugated plate heat exchangers having different chevron angles

    Science.gov (United States)

    Kılıç, Bayram; İpek, Osman

    2017-02-01

    In this study, heat transfer rate and effectiveness of corrugated plate heat exchangers having different chevron angles were investigated experimentally. Chevron angles of plate heat exchangers are β = 30° and β = 60°. For this purpose, experimentally heating system used plate heat exchanger was designed and constructed. Thermodynamic analysis of corrugated plate heat exchangers having different chevron angles were carried out. The heat transfer rate and effectiveness values are calculated. The experimental results are shown that heat transfer rate and effectiveness values for β = 60° is higher than that of the other. Obtained experimental results were graphically presented.

  14. Design and Numerical Parametric Study of Fractal Heat Exchanger

    OpenAIRE

    Huang, Zhiwei; Ling, Jiazhen; Hwang, Yunho; Aute, Vikrant; Radermacher, Reinhard

    2016-01-01

    Air-to-refrigerant heat exchangers are a main component in air-conditioning and heat pump systems and are therefore a topic of major research focus. Such heat exchangers, mainly made of fin-and-tube and microchannels, use fins to augment the heat transfer area of the air-side. Recently it has been shown that finless designs using ≤ 1 mm hydraulic diameter bare tubes can deliver better air-side heat transfer performance than conventional heat exchangers. In current study, a novel air-to-refr...

  15. Magnetic Heat Transfer Enhancements on Fin-Tube Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    Yan SU; C.T. HSU

    2007-01-01

    通过DNS方法解耦合的三维非稳态流动和固流体能量方程组,本文研究了两平行磁质平板和圆管所组成的肋片式圆管换热器单元与震荡流体间的传热过程.对不同的磁场频率和振幅的三维动态流热场的模拟结果表明增强磁场频率和振幅能很有效地增加周期平均传热强度达到强化传热的目的.%Two narrowly-gapped magnetic parallel plates embedding a circular disk was considered as a unit-cell to represent the fin-tube heat exchanger where heat from a circular tube was dissipated by a series of parallel equally-spaced thin plates in normal to the tube. The unsteady 3-D continuity,Navier-Stokes and energy equations for fluids and solids describing the convective heat transfer for the unit-cell geometry were solved numerically with DNS method. The present study aims on using oscillating flows and magnetic fields to enhance the heat transfer for various amplitudes and frequencies of the magnetic field. Results from cycle-averaged heat fluxes from the cylinder wall show that the increase in magnetic amplitude and frequency will greatly enhance the heat transfer. The effects of the oscillating magnetic field were discussed and the three dimensional flow and temperature fields were also presented.

  16. Performance of multiple mini-tube heat exchangers as an internal heat exchanger of a vapor-injection cycle heat pump

    Science.gov (United States)

    Jang, Jin Yong; Jeong, Ji Hwan

    2016-04-01

    A multiple mini-tube (MMT) heat exchanger was considered as an internal heat exchanger of vapor-injection cycle heat pump. Heat transfer and pressure drop in multiple mini-tube heat exchangers were numerically and experimentally investigated. Results show that the best performance of the MMT heat exchanger can be obtained when the intermediate-pressure two-phase refrigerant is supplied to the shell-side and this refrigerant reaches a saturated vapor state at the exit of the heat exchanger.

  17. Axial flow heat exchanger devices and methods for heat transfer using axial flow devices

    Energy Technology Data Exchange (ETDEWEB)

    Koplow, Jeffrey P.

    2016-02-16

    Systems and methods described herein are directed to rotary heat exchangers configured to transfer heat to a heat transfer medium flowing in substantially axial direction within the heat exchangers. Exemplary heat exchangers include a heat conducting structure which is configured to be in thermal contact with a thermal load or a thermal sink, and a heat transfer structure rotatably coupled to the heat conducting structure to form a gap region between the heat conducting structure and the heat transfer structure, the heat transfer structure being configured to rotate during operation of the device. In example devices heat may be transferred across the gap region from a heated axial flow of the heat transfer medium to a cool stationary heat conducting structure, or from a heated stationary conducting structure to a cool axial flow of the heat transfer medium.

  18. High temperature heat exchanger studies for applications to gas turbines

    Science.gov (United States)

    Min, June Kee; Jeong, Ji Hwan; Ha, Man Yeong; Kim, Kui Soon

    2009-12-01

    Growing demand for environmentally friendly aero gas-turbine engines with lower emissions and improved specific fuel consumption can be met by incorporating heat exchangers into gas turbines. Relevant researches in such areas as the design of a heat exchanger matrix, materials selection, manufacturing technology, and optimization by a variety of researchers have been reviewed in this paper. Based on results reported in previous studies, potential heat exchanger designs for an aero gas turbine recuperator, intercooler, and cooling-air cooler are suggested.

  19. Two-phase Flow Distribution in Heat Exchanger Manifolds

    OpenAIRE

    Vist, Sivert

    2004-01-01

    The current study has investigated two-phase refrigerant flow distribution in heat exchange manifolds. Experimental data have been acquired in a heat exchanger test rig specially made for measurement of mass flow rate and gas and liquid distribution in the manifolds of compact heat exchangers. Twelve different manifold designs were used in the experiments, and CO2 and HFC-134a were used as refrigerants.

  20. Direct contact droplet heat exchangers for thermal management in space

    Science.gov (United States)

    Bruckner, A. P.; Hertzberg, A.

    1982-01-01

    A liquid droplet heat exchanger for space applications is described which transfers heat between a gas and a liquid metal dispersed into droplets. The ability of the droplet heat exchanger to transfer heat between two media in direct contact over a wide temperature range circumvents many of the material limitations of conventional tube-type heat exchangers and does away with complicated plumbing systems and their tendency toward single point failure. Droplet heat exchangers offer large surface to volume ratios in a compact geometry, very low gas pressure drop, and high effectiveness. The application of the droplet heat exchanger in a high temperature Brayton cycle is discussed to illustrate its performance and operational characteristics.

  1. Liquid-Liquid Heat Exchanger With Zero Interpath Leakage Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future manned spacecraft will require thermal management systems that effectively and safely control the temperature in inhabited modules. Interface heat exchangers...

  2. Condensing Heat Exchanger with Hydrophilic Antimicrobial Coating

    Science.gov (United States)

    Thomas, Christopher M. (Inventor); Ma, Yonghui (Inventor)

    2014-01-01

    A multi-layer antimicrobial hydrophilic coating is applied to a substrate of anodized aluminum, although other materials may form the substrate. A silver layer is sputtered onto a thoroughly clean anodized surface of the aluminum to about 400 nm thickness. A layer of crosslinked, silicon-based macromolecular structure about 10 nm thickness overlies the silver layer, and the outermost surface of the layer of crosslinked, silicon-based macromolecular structure is hydroxide terminated to produce a hydrophilic surface with a water drop contact angle of less than 10.degree.. The coated substrate may be one of multiple fins in a condensing heat exchanger for use in the microgravity of space, which has narrow channels defined between angled fins such that the surface tension of condensed water moves water by capillary flow to a central location where it is pumped to storage. The antimicrobial coating prevents obstruction of the capillary passages.

  3. Thermal Propulsion Capture System Heat Exchanger Design

    Science.gov (United States)

    Richard, Evan M.

    2016-01-01

    One of the biggest challenges of manned spaceflight beyond low earth orbit and the moon is harmful radiation that astronauts would be exposed to on their long journey to Mars and further destinations. Using nuclear energy has the potential to be a more effective means of propulsion compared to traditional chemical engines (higher specific impulse). An upper stage nuclear engine would allow astronauts to reach their destination faster and more fuel efficiently. Testing these engines poses engineering challenges due to the need to totally capture the engine exhaust. The Thermal Propulsion Capture System is a concept for cost effectively and safely testing Nuclear Thermal Engines. Nominally, hydrogen exhausted from the engine is not radioactive, but is treated as such in case of fuel element failure. The Thermal Propulsion Capture System involves injecting liquid oxygen to convert the hydrogen exhaust into steam. The steam is then cooled and condensed into liquid water to allow for storage. The Thermal Propulsion Capture System concept for ground testing of a nuclear powered engine involves capturing the engine exhaust to be cooled and condensed before being stored. The hydrogen exhaust is injected with liquid oxygen and burned to form steam. That steam must be cooled to saturation temperatures before being condensed into liquid water. A crossflow heat exchanger using water as a working fluid will be designed to accomplish this goal. Design a cross flow heat exchanger for the Thermal Propulsion Capture System testing which: Eliminates the need for water injection cooling, Cools steam from 5800 F to saturation temperature, and Is efficient and minimizes water requirement.

  4. WASTE HEAT RECOVERY FROM BOILER OF LARGE-SCALE TEXTILE INDUSTRY

    Directory of Open Access Journals (Sweden)

    Prateep Pattanapunt

    2013-01-01

    Full Text Available Many industrial heating processes generate waste energy in textile industry; especially exhaust gas from the boiler at the same time reducing global warming. Therefore, this article will present a study the way to recovery heat waste from boiler exhaust gas by mean of shell and tube heat exchanger. Exhaust gas from boiler dyeing process, which carries a large amount of heat, energy consumptions could be decrease by using of waste-heat recovery systems. In this study, using ANASYS simulation performs a thermodynamics analysis. An energy-based approach is performed for optimizing the effective working condition for waste-heat recovery with exhaust gas to air shell and tube heat exchanger. The variations of parameters, which affect the system performance such as, exhaust gas and air temperature, velocity and mass flow rate and moisture content is examined respectively. From this study, it was found that heat exchanger could be reduced temperature of exhaust gases and emission to atmosphere and the time payback is the fastest. The payback period was determined about 6 months for investigated ANSYS. The air is circulated in four passes from the top to the bottom of the test section, in overall counter-flow with exhaust gas. The front area is 1720×1720 mm, the flow length 7500 mm, the inner and outer diameter of exhaust gas is 800 mm, the tube assembly consist of 196 tubes, the tube diameter is 76.2 mm, the tube thickness is 2.6 mm, the tube length is 4500 mm, the tube length of air inner and outer is 500 mm. The result show that, the boiler for superheated type there are exhaust gas temperature is 190°C, 24% the moisture content of fuel and there are palm kernel shell 70 tons day-1 which there are the high temperature after the heat exchanger, 150°C. It was occurred acid rain. The hot air from heat exchanger process can be reduced the moisture of palm kernel shell fuel to 15%.The fuel consumption is reduced by about 2.05% (322.72 kJ kg-1

  5. Optimization for entransy dissipation minimization in heat exchanger

    Institute of Scientific and Technical Information of China (English)

    XIA ShaoJun; CHEN LinGen; SUN FengRui

    2009-01-01

    A common of two-fluid flow heat exchanger, in which the heat transfer between high-and low-temperature sides obeys Newton's law [q∝△(T)], is studied in this paper. By taking entransy dissipation minimization as optimization objective, the optimum parameter distributions in the heat ex-changer are derived by using optimal control theory under the condition of fixed heat load. The condition corresponding to the minimum entransy dissipation is that corresponding to a constant heat flux density. Three kinds of heat exchangers, including parallel flow, condensing flow and counter-flow, are considered, and the results show that only the counter-flow heat exchanger can realize the entransy dissipation minimization in the heat transfer process. The obtained results for entransy dissipation minimization are also compared with those obtained for entropy generation minimization by numerical examples.

  6. Simulation Studies on A Cross Flow Plate Fin Heat Exchanger

    OpenAIRE

    Thirumarimurugan, M.; Kannadasan, T.; E. Ramasamy

    2008-01-01

    Compact heat exchangers which were initially developed for the aerospace industries in the1940s have been considerably improved in the past few years. The main reasons for the goodperformance of compact heat exchangers are their special design which includes turbulent which inturn use high heat transfer coefficient and resists fouling, and maximum temperature driving forcebetween the hot and cold fluids. Numerous types use special enhancement techniques to achieve therequired heat transfer in...

  7. Fouling corrosion in aluminum heat exchangers

    Directory of Open Access Journals (Sweden)

    Su Jingxin

    2015-06-01

    Full Text Available Fouling deposits on aluminum heat exchanger reduce the heat transfer efficiency and cause corrosion to the apparatus. This study focuses on the corrosive behavior of aluminum coupons covered with a layer of artificial fouling in a humid atmosphere by their weight loss, Tafel plots, electrochemical impedance spectroscopy (EIS, and scanning electron microscope (SEM observations. The results reveal that chloride is one of the major elements found in the fouling which damages the passive film and initiates corrosion. The galvanic corrosion between the metal and the adjacent carbon particles accelerates the corrosive process. Furthermore, the black carbon favors the moisture uptake, and gives the dissolved oxygen greater chance to migrate through the fouling layer and form a continuous diffusive path. The corrosion rate decreasing over time is conformed to electrochemistry measurements and can be verified by Faraday’s law. The EIS results indicate that the mechanism of corrosion can be interpreted by the pitting corrosion evolution mechanism, and that pitting was observed on the coupons by SEM after corrosive exposure.

  8. Combined Steady-State and Dynamic Heat Exchanger Experiment

    Science.gov (United States)

    Luyben, William L.; Tuzla, Kemal; Bader, Paul N.

    2009-01-01

    This paper describes a heat-transfer experiment that combines steady-state analysis and dynamic control. A process-water stream is circulated through two tube-in-shell heat exchangers in series. In the first, the process water is heated by steam. In the second, it is cooled by cooling water. The equipment is pilot-plant size: heat-transfer areas…

  9. A Liquid-Liquid Thermoelectric Heat Exchanger as a Heat Pump for Testing Phase Change Material Heat Exchangers

    Science.gov (United States)

    Sheth, Rubik B.; Makinen, Janice; Le, Hung V.

    2016-01-01

    The primary objective of the Phase Change HX payload on the International Space Station (ISS) is to test and demonstrate the viability and performance of Phase Change Material Heat Exchangers (PCM HX). The system was required to pump a working fluid through a PCM HX to promote the phase change material to freeze and thaw as expected on Orion's Multipurpose Crew Vehicle. Due to limitations on ISS's Internal Thermal Control System, a heat pump was needed on the Phase Change HX payload to help with reducing the working fluid's temperature to below 0degC (32degF). This paper will review the design and development of a TEC based liquid-liquid heat exchanger as a way to vary to fluid temperature for the freeze and thaw phase of the PCM HX. Specifically, the paper will review the design of custom coldplates and sizing for the required heat removal of the HX.

  10. Principle of uniformity of temperature difference field in heat exchanger

    Institute of Scientific and Technical Information of China (English)

    过增元; 李志信; 周森泉; 熊大曦

    1996-01-01

    A principle of uniformity of temperature difference field (TDF) in heat exchangers is advanced.It states that the more uniform the temperature difference field,the higher the effectiveness of heat exchanger for a given NTU and C,.Analytical and numerical results on the uniformity of TDF and effectiveness of thirteen types of heat exchangers show the validity of the uniformity principle.Its further verification is given by the asymptotical solution of TDF in terms of a recurrence formula of heat transfer area distribution.The analyses of entropy generation caused by heat transfer indicate that the uniformity principle is based on the second law of thermodynamics.Two ways,redistributing heat transfer areas and varying the connection between tubes,are presented for the improvement of the uniformity of TDF and the consequent increase of effectiveness for crossflow heat exchangers.

  11. Analyze single- and multiple-pass heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Ratnam, R. (Univ. of Illinois, Urbana-Champagne, IL (United States)); Patwardhan, V.S. (National Chemical Lab., Poona (India))

    1993-06-01

    Heat exchanger calculations generally address the design problem (where for given process conditions and heat exchanger duty, a geometry is selected and the area is estimated) or they address the simulation problem (where for a given geometry, overall heat-transfer coefficient, and heat-transfer area, the heat duty and the outlet temperatures are determined). The latter is particularly useful when predicting the performance of heat exchanger networks. This article presents a novel graphical method that is suitable for design, simulation, and some operational studies, and is applicable to both single-pass and multipass heat exchangers. The main advantage of these graphs over earlier graphical representations is that they are uniformly applicable for a variety of problems. Although graphical techniques are useful for understanding underlying relationships, they are not suitable for computer implementation. However, these relationships can be computerized fairly easily.

  12. A Modified Entropy Generation Number for Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    This paper demonstrates the difference between the entropy generation number method proposed by Bejian and the method of entropy generation per unit amount of heat transferred in analyzing the ther-modynamic performance of heat exchangers,points out the reason for leading to the above difference.A modified entropy generation number for evaluating the irreversibility of heat exchangers is proposed which is in consistent with the entropy generation per unit amount of heat transferred in entropy generation analysis.The entropy generated by friction is also investigated.Results show that when the entropy generated by friction in heat exchangers in taken into account,there is a minimum total entropy generation number while the NTU and the ratio of heat capacity rates vary.The existence of this minimum is the prerequisite of heat exchanger optimization.

  13. Design Calculation of Heat Exchanger of Reflooding Test

    Institute of Scientific and Technical Information of China (English)

    DUAN; Ming-hui; LI; Xiang; LI; Wei-qing

    2013-01-01

    The heat exchanger is very important to the major loop of the reflooding test.It can cool the fluid in the loop,so that the fluid temperature can agree with the requirements of the major pump and the preheater.Herein,an evaporative exchanger with U-shape tubes is adopted.The heat transfer calculation

  14. Heat exchanger with helical bundles of finned tubes

    Energy Technology Data Exchange (ETDEWEB)

    Eyking, H.J.

    1975-01-23

    The invention applies to a heat exchanger with helical bundles of tubes consisting of finned tubes separated by spacers. The spacers are designed as closed holding cylinders with holding devices for the tube bundles, each ot which surrounds a bundle of tubes. This construction serves to simplify the production process and to enable the use of the heat exchanger at higher loads.

  15. Heat Exchanger Network Retrofit Design by Eliminating Cross Pinch Heat Exchangers

    Directory of Open Access Journals (Sweden)

    Beabu K. Piagbo

    2013-01-01

    Full Text Available The rising cost of energy and environmental concerns are leading the petrochemical industry to search for methods of reducing energy consumption in refinery operations. To address this issue the research presented in this paper explores retrofit design for increasing the energy efficiency of Crude Distillation Units (CDUs. The case study presented uses monitored plant data from the preheat section of the CDU in a Refinery in the Niger Delta region of Nigeria, West Africa. Aspen Energy Analyser® software developed by Aspen Technologies is used in the analysis of this data. The research findings suggest that a retrofit design eliminating all cross pinch heat exchangers is the best retrofit design in terms of improving the energy performance of CDUs. There was an 84.62% and 92.31% reduction in the number of the heat exchangers used and the number of shells respectively. There were 16.57%, 2.74%, and 13.98% reductions in the operating cost, capital cost, and total cost respectively. 3.68% of the area became available for heat transfer. These gains were achieved despite a 12.27% increase in the heating demand. This design is therefore recommended to be applied after additional cost consideration.

  16. Cyclic high temperature heat storage using borehole heat exchangers

    Science.gov (United States)

    Boockmeyer, Anke; Delfs, Jens-Olaf; Bauer, Sebastian

    2016-04-01

    The transition of the German energy supply towards mainly renewable energy sources like wind or solar power, termed "Energiewende", makes energy storage a requirement in order to compensate their fluctuating production and to ensure a reliable energy and power supply. One option is to store heat in the subsurface using borehole heat exchangers (BHEs). Efficiency of thermal storage is increasing with increasing temperatures, as heat at high temperatures is more easily injected and extracted than at temperatures at ambient levels. This work aims at quantifying achievable storage capacities, storage cycle times, injection and extraction rates as well as thermal and hydraulic effects induced in the subsurface for a BHE storage site in the shallow subsurface. To achieve these aims, simulation of these highly dynamic storage sites is performed. A detailed, high-resolution numerical simulation model was developed, that accounts for all BHE components in geometrical detail and incorporates the governing processes. This model was verified using high quality experimental data and is shown to achieve accurate simulation results with excellent fit to the available experimental data, but also leads to large computational times due to the large numerical meshes required for discretizing the highly transient effects. An approximate numerical model for each type of BHE (single U, double U and coaxial) that reduces the number of elements and the simulation time significantly was therefore developed for use in larger scale simulations. The approximate numerical model still includes all BHE components and represents the temporal and spatial temperature distribution with a deviation of less than 2% from the fully discretized model. Simulation times are reduced by a factor of ~10 for single U-tube BHEs, ~20 for double U-tube BHEs and ~150 for coaxial BHEs. This model is then used to investigate achievable storage capacity, injection and extraction rates as well as induced effects for

  17. A concept of PWR using plate and shell heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Luciano Ondir; Andrade, Delvonei Alves de, E-mail: luciano.ondir@gmail.com, E-mail: delvonei@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    In previous work it was verified the physical possibility of using plate and shell heat exchangers for steam generation in a PWR for merchant ships. This work studies the possibility of using GESMEX commercial of the shelf plate and shell heat exchanger of series XPS. It was found it is feasible for this type of heat exchanger to meet operational and accidental requirements for steam generation in PWR. Additionally, it is proposed an arrangement of such heat exchangers inside the reactor pressure vessel. Such arrangement may avoid ANSI/ANS51.1 nuclear class I requirements on those heat exchangers because they are contained in the reactor coolant pressure barrier and play no role in accidental scenarios. Additionally, those plates work under compression, preventing the risk of rupture. Being considered non-nuclear safety, having a modular architecture and working under compression may turn such architectural choice a must to meet safety objectives with improved economics. (author)

  18. The heat exchanger of small pellet boiler for phytomass

    Science.gov (United States)

    Mičieta, Jozef; Lenhard, Richard; Jandačka, Jozef

    2014-08-01

    Combustion of pellets from plant biomass (phytomass) causes various troubles. Main problem is slagging ash because of low melting temperature of ash from phytomass. This problem is possible to solve either improving energetic properties of phytomass by additives or modification of boiler construction. A small-scale boiler for phytomass is different in construction of heat exchanger and furnace mainly. We solve major problem - slagging ash, by decreasing combustion temperature via redesign of pellet burner and boiler body. Consequence of lower combustion temperature is also lower temperature gradient of combustion gas. It means that is necessary to design larger heat exchanging surface. We plane to use underfed burner, so we would utilize circle symmetry heat exchanger. Paper deals design of heat exchanger construction with help of CFD simulation. Our purpose is to keep uniform water flux and combustion gas flux in heat exchanger without zone of local overheating and excess cooling.

  19. Modeling of Heat Exchange with Developed Nucleate Boiling on Tenons

    Directory of Open Access Journals (Sweden)

    A. V. Оvsiannik

    2007-01-01

    Full Text Available The paper proposes a thermal and physical model for heat exchange processes with developed nucleate boiling on the developed surfaces (tenons with various contours of heat transfer surface. Dependences for calculating convective heat exchange factor have been obtained on the basis of modeling representation. Investigations have shown that an intensity of convective heat exchange does not depend on tenon profile when boiling takes place on the tenons. The intensity is determined by operating conditions, thermal and physical properties of liquid, internal characteristics of boiling processes and geometrical characteristics of a tenon.

  20. FLUENT软件对管壳式换热器壳程流体数值模拟方法可行性的验证%Confirmation of the Feasibility of FLUENT Software Applied to the Shell Side Fluid Numerical Simulation of the Shell-and-Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    王艳云; 李志安; 刘红禹; 宿萌; 孟令一; 吕春红

    2007-01-01

    鉴于单弓形折流板管壳式换热器应用的广泛性,对传统单弓形折流板管壳式换热器进行了数值模拟分析,验证了FLUENT软件应用到管壳式换热器壳程流体数值模拟方法的可行性,并为换热器其它壳程支撑结构的研究提供了一定的理论依据.

  1. Automatización y optimización del diseño de intercambiadores de calor de tubo y coraza mediante el método de Taborek//Automatization and optimization of shell and tube heat exchangers design using the method of Taborek

    OpenAIRE

    Maida Bárbara Reyes‐Rodríguez; Jorge Laureano Moya‐Rodríguez; Oscar Miguel Cruz‐Fonticiella; Eduardo Miguel Fírvida‐Donéstevez; José Alberto Velázquez‐Pérez

    2014-01-01

    Los intercambiadores de calor del tipo de coraza y tubo constituyen la parte más importante de los equipos de transferencia de calor sin combustión en las plantas de procesos químicos. Existen en la literatura numerosos métodos para el diseño de Intercambiadores de calor de tubo y coraza. Entre los más conocidos se encuentran el Método de Kern, el Método de Bell Delaware, el Método de Tinker, elMétodo de Wills and Johnston y el Método de Taborek. El presente trabajo tiene como objetivo descri...

  2. Principle of equipartition of entransy dissipation for heat exchanger design

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In the present work,a principle of equipartition of entransy dissipation(EoED) for heat exchanger design is established,which says that for a heat exchanger design with given heat duty and heat transfer area,the total entransy dissipation rate reaches the minimum when the local entransy dissipation rate is uniformly distributed along the heat exchanger.When the heat transfer coefficient is unfixed,the total entransy dissipation obtained by the EoED principle is less than that obtained by the principle of equipartition of temperature difference(EoTD).Furthermore,the exchanger effectiveness obtained by the EoED principle is larger than that obtained by the EoTD principle.When the heat transfer coefficient is fixed,the EoED principle is equivalent to the EoTD principle.We show that the equipartition of entropy production(EoEP) and EoED principles give rise to difference in entropy generation and entransy dissipation for a heat exchanger optimization design.The discrepancies are caused by distinct features of entropy production minimization and entransy dissipation minimization principles,the former is to optimize the design of heat exchanger by making the lost available work minimum,while the latter is not involved with heat-work conversion.It is found that the entropy generation number is not suitable for evaluating heat exchanger performance,since it directly depends on the inlet and outlet temperatures of working fluids.On the contrary,the entransy dissipation number is not directly related to the inlet and outlet temperatures of working fluids.Therefore,the entransy dissipation number is more suitable for serving as a criterion to evaluate heat exchanger performance.

  3. An experimental study of a pin-fin heat exchanger

    OpenAIRE

    Ramthun, David L.

    2003-01-01

    Approved for public release; distribution is unlimited A detailed experimental study has been carried out on the heat transfer and pressure drop characteristics of a compact heat exchanger with pin fins. A modular wind-tunnel with a rectangular cross-section duct-flow area was constructed that would accommodate the heat exchanger test section with varying pin designs. The flow in the tunnel was achieved through a suction-type blower, and a leading entrance length section was added to achie...

  4. Effect of Baffle Opening on the Performance of Shell-and-T ube Heat Exchanger%折流板开孔对管壳式换热器性能的影响

    Institute of Scientific and Technical Information of China (English)

    郭土; 马贵阳; 石龙; 黄腾龙

    2013-01-01

    The traditional baffle heat exchanger is widely used for its simple structure ,safety and reliability and adaptability advantages ,but the traditional baffle heat exchanger has many weaknesses :its thermal efficiency is low ,shell side pressure loss is bigger and easy scaling .It is a very important engineering significance through improving the vertical baffles'structure to ameliorate the shell and tube heat exchanger's flow and heat transfer condition of shell side and reduce its energy dissipation . Baffle opening to improve the structure of a gap 0 .2D height was studied by numerical simulation method .The velocity field and temperature field numerically simulated ordinary baffles heat exchanger and baffle opening heat exchanger . Under the condition of the same entering velocity of shell side ,the thermal effect of baffle opening heat exchanger is better than ordinary vertical baffle plate heat exchanger .And when the entering velocity of shell side is slow ,the effect is better .%传统的弓形折流板换热器因其结构简单、安全可靠及适应性强等优点应用非常广泛,但是传统的弓形折流板换热器换热效率较低,壳程压力损失较大,容易结垢。因此,通过对弓形折流板结构进行改进以改善管壳式换热器的壳程流动传热状况,减小其能耗损失具有十分重大的工程意义。采用数值模拟的方法,对缺口高度为0.2D的折流板进行开孔优化研究,对不同壳程进口流速下的普通弓形折流板换热器和折流板开孔换热器的壳程流场及温度场分别进行了数值模拟。在壳程进口流速相等的条件下,折流板开孔的换热器比普通弓形折流板换热器的换热效果好;壳程进口速度较低时,效果最明显。

  5. Manufacturing Technique of U Rod Baffle Heat Exchanger under High Temperature and Pressure%高温高压U型折流杆换热器的制造技术

    Institute of Scientific and Technical Information of China (English)

    赵洪勇

    2015-01-01

    Rod baffle heat exchanger is a kind of shell-and-tube heat exchanger made up with a series of small baffle rods.It is designed for the purpose of reducing the flow-induced tube vibration in normal plate baffle heat exchanger.Coordinate precision between rod baffles and heat exchange tube determines wheth-er the bundles in heat exchanger meet the certain design requirements.The technique of manufacturing U rod baffle heat exchanger under high temperature and pressure shall overcome the difficulties of baffle ring assembly,heat exchange tube bending,stress relief treatment and high assembly precision.Making break-throughs on above difficulties,our company tackles the processing and manufacturing problems in fabrica-ting a petrochemical company second converter waste heat boiler(E -8).%折流杆式换热器是一种壳体内的折流元件由一系列细小的折流杆组成的管壳式换热器,是为了改善常规的板式折流板换热器的流体诱导振动而设计的。折流杆与换热管之间的配合是否精密,决定了换热器管束是否能够满足设计技术要求。而对于高温高压工况下的 U 型折流杆换热器,在制造技术上需克服折流圈的装配、换热管消应力处理、装配精度高等相应难题。在某石化公司第二转换炉废热锅炉(E -8)制造过程中,针对以上制造难点进行了攻关,通过提高换热管的精度要求、采用模具组装法保证折流圈组对间隙、对每个规格的 U 型管在弯制中进行预估,并采用整体入炉热处理方法控制变形量,解决了制造过程中的加工工艺以及制造上的难题。

  6. Optimization of the Single Staggered Wire and Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Arsana I Made

    2016-01-01

    Full Text Available Wire and tube heat exchanger consists of a coiled tube, and wire is welded on the two sides of it in normal direction of the tube. Generally,wire and tube heat exchanger uses inline wire arrangement between the two sides, whereas in this study, it used staggered wire arrangement that reduces the restriction of convection heat transfer. This study performed the optimization of single staggered wire and tube heat exchanger to increase the capacity and reduce the mass of the heat exchanger. Optimization was conducted with the Hooke-Jeeves method, which aims to optimize the geometry of the heat exchanger, especially on the diameter (dw and the distance between wires (pw. The model developed to present heat transfer correlations on single staggered wire and tube heat exchanger was valid. The maximum optimization factor obtained when the diameter wire was 0.9 mm and the distance between wires (pw was 11 mm with the fref value = 1.5837. It means that the optimized design only using mass of 59,10 % and could transfer heat about 98,5 % from the basis design.

  7. SILICON CARBIDE CERAMICS FOR COMPACT HEAT EXCHANGERS

    Energy Technology Data Exchange (ETDEWEB)

    DR. DENNIS NAGLE; DR. DAJIE ZHANG

    2009-03-26

    Silicon carbide (SiC) materials are prime candidates for high temperature heat exchangers for next generation nuclear reactors due to their refractory nature and high thermal conductivity at elevated temperatures. This research has focused on demonstrating the potential of liquid silicon infiltration (LSI) for making SiC to achieve this goal. The major advantage of this method over other ceramic processing techniques is the enhanced capability of making high dense, high purity SiC materials in complex net shapes. For successful formation of net shape SiC using LSI techniques, the carbon preform reactivity and pore structure must be controlled to allow the complete infiltration of the porous carbon structure which allows complete conversion of the carbon to SiC. We have established a procedure for achieving desirable carbon properties by using carbon precursors consisting of two readily available high purity organic materials, crystalline cellulose and phenolic resin. Phenolic resin yields a glassy carbon with low chemical reactivity and porosity while the cellulose carbon is highly reactive and porous. By adjusting the ratio of these two materials in the precursor mixtures, the properties of the carbons produced can be controlled. We have identified the most favorable carbon precursor composition to be a cellulose resin mass ratio of 6:4 for LSI formation of SiC. The optimum reaction conditions are a temperature of 1800 C, a pressure of 0.5 Torr of argon, and a time of 120 minutes. The fully dense net shape SiC material produced has a density of 2.96 g cm{sup -3} (about 92% of pure SiC) and a SiC volume fraction of over 0.82. Kinetics of the LSI SiC formation process was studied by optical microscopy and quantitative digital image analysis. This study identified six reaction stages and provided important understanding of the process. Although the thermal conductivity of pure SiC at elevated temperatures is very high, thermal conductivities of most commercial Si

  8. Exergy Transfer Characteristics on Low Temperature Heat Exchangers

    Science.gov (United States)

    Wu, S. Y.; Yuan, X. F.; Li, Y. R.; Peng, L.

    By analyzing exergy transfer process of the low temperature heat exchangers operating below the surrounding temperature, the concept of exergy transfer coefficient is put forward and the expressions which involving relevant variables for the exergy transfer coefficient, the heat transfer units number and the ratio of cold to hot fluids heat capacity rate, etc. are derived. Taking the parallel flow, counter flow and cross flow low temperature heat exchangers as examples, the numerical results of exergy transfer coefficient are given and the comparison of exergy transfer coefficient with heat transfer coefficient is analyzed.

  9. Investigation of Brazed Plate Heat Exchangers With Variable Chevron Angles

    Directory of Open Access Journals (Sweden)

    S. Muthuraman

    2013-08-01

    Full Text Available - Experiments to measure the condensation heat transfer coefficient and the pressure drop in brazed plate heat exchangers (BPHEs were performed with the refrigerants R410A and R22. Brazed plate heat exchangers with different chevron angles of 45°, 35°, and 20° were used. Varying the mass flux, the condensation temperature, and the vapor quality of the refrigerant, we measured the condensation heat transfer coefficient and the pressure drops. Both the heat transfer coefficient and the pressure drop increased proportionally with the mass flux and the vapor quality and inversely with the condensation temperature and the chevron angle.

  10. Heat Recovery Ventilation for Housing: Air-to-Air Heat Exchangers.

    Science.gov (United States)

    Corbett, Robert J.; Miller, Barbara

    The air-to-air heat exchanger (a fan powered ventilation device that recovers heat from stale outgoing air) is explained in this six-part publication. Topic areas addressed are: (1) the nature of air-to-air heat exchangers and how they work; (2) choosing and sizing the system; (3) installation, control, and maintenance of the system; (4) heat…

  11. Effect of size sprinkled heat exchange surface on developing boiling

    Directory of Open Access Journals (Sweden)

    Petr Kracík

    2016-06-01

    Full Text Available This article presents research of sprinkled heat exchangers. This type of research has become rather topical in relation to sea water desalination. This process uses sprinkling of exchangers which rapidly separates vapour phase from a liquid phase. Applications help better utilize low-potential heat which is commonly wasted in utility systems. Low-potential heat may increase utilization of primary materials. Our ambition is to analyse and describe the whole sprinkled exchanger. Two heat exchangers were tested with a similar tube pitch: heat exchanger no. 1 had a four-tube bundle and heat exchanger no. 2 had eight-tube bundle. Efforts were made to maintain similar physical characteristics. They were tested at two flow rates (ca 0.07 and 0.11 kg s−1 m−1 and progress of boiling on the bundle was observed. Initial pressure was ca 10 kPa (abs at which no liquid was boiling at any part of the exchanger; the pressure was then lowered. Other input parameters were roughly similar for both flow rates. Temperature of heating water was ca 50°C at a constant flow rate of ca 7.2 L min−1. Results of our experiments provide optimum parameters for the given conditions for both tube bundles.

  12. Optimization of Transient Heat Exchanger Performance for Improved Energy Efficiency

    Science.gov (United States)

    Bran Anleu, Gabriela; Kavehpour, Pirouz; Lavine, Adrienne; Wirz, Richard

    2014-11-01

    Heat exchangers are used in a multitude of applications within systems for energy generation, energy conversion, or energy storage. Many of these systems (e.g. solar power plants) function under transient conditions, but the design of the heat exchangers is typically optimized assuming steady state conditions. There is a potential for significant energy savings if the transient behavior of the heat exchanger is taken into account in designing the heat exchanger by optimizing its operating conditions in relation to the transient behavior of the overall system. The physics of the transient behavior of a heat exchanger needs to be understood to provide design parameters for transient heat exchangers to deliver energy savings. A numerical model was used to determine the optimized mass flow rates thermal properties for a thermal energy storage system. The transient behavior is strongly linked to the dimensionless parameters relating fluid properties, the mass flow rates, and the temperature of the fluids at the inlet of each stream. Smart metals, or advanced heat exchanger surface geometries and methods of construction will be used to meet the three goals mentioned before: 1) energy and cost reduction, 2) size reduction, and 3) optimal performance for all modes of operation.

  13. Basic Principles for Calculating Heat Exchanger Characteristics under Conditions of Environmental Heat Losses

    Directory of Open Access Journals (Sweden)

    B. A. Bayrashevsky

    2007-01-01

    Full Text Available The paper considers two most characteristic models of heat exchange mechanisms in heaters with due account of environmental heat losses. As a result of executed investigations a list of corresponding engineering formulae has been developed which can be used for determination of heat engineering characteristics of heat exchangers and calculation of heating modes of their operation.Authors of the paper have elaborated a special «Heat Exchanger» programming file that corroborates reliability of the executed analysis and makes it possible to carry out a number of the required calculations.

  14. The predictive protective control of the heat exchanger

    Science.gov (United States)

    Nevriva, Pavel; Filipova, Blanka; Vilimec, Ladislav

    2016-06-01

    The paper deals with the predictive control applied to flexible cogeneration energy system FES. FES was designed and developed by the VITKOVICE POWER ENGINEERING joint-stock company and represents a new solution of decentralized cogeneration energy sources. In FES, the heating medium is flue gas generated by combustion of a solid fuel. The heated medium is power gas, which is a gas mixture of air and water steam. Power gas is superheated in the main heat exchanger and led to gas turbines. To protect the main heat exchanger against damage by overheating, the novel predictive protective control based on the mathematical model of exchanger was developed. The paper describes the principle, the design and the simulation of the predictive protective method applied to main heat exchanger of FES.

  15. Microchannel crossflow fluid heat exchanger and method for its fabrication

    Science.gov (United States)

    Swift, Gregory W.; Migliori, Albert; Wheatley, John C.

    1985-01-01

    A microchannel crossflow fluid heat exchanger and a method for its fabrication are disclosed. The heat exchanger is formed from a stack of thin metal sheets which are bonded together. The stack consists of alternating slotted and unslotted sheets. Each of the slotted sheets includes multiple parallel slots which form fluid flow channels when sandwiched between the unslotted sheets. Successive slotted sheets in the stack are rotated ninety degrees with respect to one another so as to form two sets of orthogonally extending fluid flow channels which are arranged in a crossflow configuration. The heat exchanger has a high surface to volume ratio, a small dead volume, a high heat transfer coefficient, and is suitable for use with fluids under high pressures. The heat exchanger has particular application in a Stirling engine that utilizes a liquid as the working substance.

  16. The influence of heat exchanger design on the synthesis of heat exchanger networks

    Directory of Open Access Journals (Sweden)

    Liporace F.S.

    2000-01-01

    Full Text Available Heat exchanger network (HEN synthesis has been traditionally performed without accounting for a more detailed unit design, which is important since the final HEN may require unfeasible units. Recently, publications on this matter have appeared, as well as softwares that simultaneously perform synthesis and units design. However, these publications do not clearly show the influence of the new added features on the final HEN. Hence, this work aims at showing that units' design can strongly affect the final HEN. Improvements on heat transfer area and total annual cost estimations, which influence the HEN structural evolution, are the main responsible for that. It is also shown the influence of some design bounds settings, which can indicate an unfeasible unit design and, therefore, the need for a new match search or the maintenance of a loop. An example reported in the literature is used to illustrate the discussion.

  17. Temperatures and Heat Flows in a Soil Enclosing a Slinky Horizontal Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Pavel Neuberger

    2014-02-01

    Full Text Available Temperature changes and heat flows in soils that host “slinky”-type horizontal heat exchangers are complex, but need to be understood if robust quantification of the thermal energy available to a ground-source heat pump is to be achieved. Of particular interest is the capacity of the thermal energy content of the soil to regenerate when the heat exchangers are not operating. Analysis of specific heat flows and the specific thermal energy regime within the soil, including that captured by the heat-exchangers, has been characterised by meticulous measurements. These reveal that high concentrations of antifreeze mix in the heat-transfer fluid of the heat exchanger have an adverse impact on heat flows discharged into the soil.

  18. Control strategies in a thermal oil - Molten salt heat exchanger

    Science.gov (United States)

    Roca, Lidia; Bonilla, Javier; Rodríguez-García, Margarita M.; Palenzuela, Patricia; de la Calle, Alberto; Valenzuela, Loreto

    2016-05-01

    This paper presents a preliminary control scheme for a molten salt - thermal oil heat exchanger. This controller regulates the molten salt mass flow rate to reach and maintain the desired thermal oil temperature at the outlet of the heat exchanger. The controller architecture has been tested using an object-oriented heat exchanger model that has been validated with data from a molten salt testing facility located at CIEMAT-PSA. Different simulations are presented with three different goals: i) to analyze the controller response in the presence of disturbances, ii) to demonstrate the benefits of designing a setpoint generator and iii) to show the controller potential against electricity price variations.

  19. SILICON CARBIDE CERAMICS FOR COMPACT HEAT EXCHANGERS

    Energy Technology Data Exchange (ETDEWEB)

    DR. DENNIS NAGLE; DR. DAJIE ZHANG

    2009-03-26

    Silicon carbide (SiC) materials are prime candidates for high temperature heat exchangers for next generation nuclear reactors due to their refractory nature and high thermal conductivity at elevated temperatures. This research has focused on demonstrating the potential of liquid silicon infiltration (LSI) for making SiC to achieve this goal. The major advantage of this method over other ceramic processing techniques is the enhanced capability of making high dense, high purity SiC materials in complex net shapes. For successful formation of net shape SiC using LSI techniques, the carbon preform reactivity and pore structure must be controlled to allow the complete infiltration of the porous carbon structure which allows complete conversion of the carbon to SiC. We have established a procedure for achieving desirable carbon properties by using carbon precursors consisting of two readily available high purity organic materials, crystalline cellulose and phenolic resin. Phenolic resin yields a glassy carbon with low chemical reactivity and porosity while the cellulose carbon is highly reactive and porous. By adjusting the ratio of these two materials in the precursor mixtures, the properties of the carbons produced can be controlled. We have identified the most favorable carbon precursor composition to be a cellulose resin mass ratio of 6:4 for LSI formation of SiC. The optimum reaction conditions are a temperature of 1800 C, a pressure of 0.5 Torr of argon, and a time of 120 minutes. The fully dense net shape SiC material produced has a density of 2.96 g cm{sup -3} (about 92% of pure SiC) and a SiC volume fraction of over 0.82. Kinetics of the LSI SiC formation process was studied by optical microscopy and quantitative digital image analysis. This study identified six reaction stages and provided important understanding of the process. Although the thermal conductivity of pure SiC at elevated temperatures is very high, thermal conductivities of most commercial Si

  20. Experimental determination of correlations for mean heat transfer coefficients in plate fin and tube heat exchangers

    Science.gov (United States)

    Taler, Dawid

    2012-09-01

    This paper presents a numerical method for determining heat transfer coefficients in cross-flow heat exchangers with extended heat exchange surfaces. Coefficients in the correlations defining heat transfer on the liquid- and air-side were determined using a nonlinear regression method. Correlation coefficients were determined from the condition that the sum of squared liquid and air temperature differences at the heat exchanger outlet, obtained by measurements and those calculated, achieved minimum. Minimum of the sum of the squares was found using the Levenberg-Marquardt method. The uncertainty in estimated parameters was determined using the error propagation rule by Gauss. The outlet temperature of the liquid and air leaving the heat exchanger was calculated using the analytical model of the heat exchanger.

  1. EVALUASI KINERJA HEAT EXCHANGER DENGAN METODE FOULING F

    Directory of Open Access Journals (Sweden)

    Bambang Setyoko

    2012-02-01

    Full Text Available The performance of heat exchangers usually deteriorates with time as a result of accumulation of depositson heat transfer surfaces. The layer of deposits represents additional resistance to heat transfer and causesthe rate of heat transfer in a heat exchanger to decrease. The net effect of these accumulations on heattransfer is represented by a fouling factor Rf , which is a measure of the thermal resistance introduced byfouling.In this case, the type of fouling is the precipitation of solid deposits in a fluid on the heat transfer surface.The mineral deposits forming on the inner and the outer surfaces of fine tubes in the heat exchanger. Thefouling factor is increases with time as the solid deposits build up on the heat exchanger surface. Foulingincreases with increasing temperature and decreasing velocity.In this research, we obtain the coefisien clean overal 5,93 BTU/h.ft2.oF, Dirt factor 0,004 BTU/h.ft2 0F,Pressure drope in tube 2,84 . 10-3 Psi and pressure drope in shell 4,93 . 10-4 Psi.This result are less thanthe standard of parameter. Its means this Heat exchanger still clean relativity and can operate continousslywithout cleaning.

  2. Low Cost Polymer heat Exchangers for Condensing Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, Thomas [Brookhaven National Lab. (BNL), Upton, NY (United States); Trojanowski, Rebecca [Brookhaven National Lab. (BNL), Upton, NY (United States); Wei, George [Brookhaven National Lab. (BNL), Upton, NY (United States); Worek, Michael [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-30

    Work in this project sought to develop a suitable design for a low cost, corrosion resistant heat exchanger as part of a high efficiency condensing boiler. Based upon the design parameters and cost analysis several geometries and material options were explored. The project also quantified and demonstrated the durability of the selected polymer/filler composite under expected operating conditions. The core material idea included a polymer matrix with fillers for thermal conductivity improvement. While the work focused on conventional heating oil, this concept could also be applicable to natural gas, low sulfur heating oil, and biodiesel- although these are considered to be less challenging environments. An extruded polymer composite heat exchanger was designed, built, and tested during this project, demonstrating technical feasibility of this corrosion-resistant material approach. In such flue gas-to-air heat exchangers, the controlling resistance to heat transfer is in the gas-side convective layer and not in the tube material. For this reason, the lower thermal conductivity polymer composite heat exchanger can achieve overall heat transfer performance comparable to a metal heat exchanger. However, with the polymer composite, the surface temperature on the gas side will be higher, leading to a lower water vapor condensation rate.

  3. Multiphysics Numerical Modeling of a Fin and Tube Heat Exchanger

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

    2015-01-01

    In the present research work, a modeling effort to predict the performance of a liquid-gas type fin and tube heat exchanger design is made. Three dimensional (3D) steady state numerical model is developed using commercial software COMSOL Multiphysics based on finite element method (FEM......). For the purposes here, only gas flowing over the fin side is simulated assuming constant inner tube wall temperature. The study couples conjugate heat transfer mechanism with turbulent flow in order to describe the temperature and velocity profile. In addition, performance characteristics of the heat exchanger...... design in terms of heat transfer and pressure loss are determined by parameters such as overall heat transfer coefficient, Colburn j-factor, flow resistance factor, and efficiency index. The model provides useful insights necessary for optimization of heat exchanger design....

  4. Numerical Analysis of Tube-Fin Heat Exchanger using Fluent

    Directory of Open Access Journals (Sweden)

    M. V. Ghori

    2012-08-01

    Full Text Available Three-dimensional CFD simulations are carried out to investigate heat transfer and fluid flow characteristics of two-row plain Tube and Fin heat exchanger using FLUENT software. Heat transfer and pressure drop characteristics of the heat exchanger are investigated for Reynolds numbers ranging from 330 to 7000. Model geometry is created and meshed by using GAMBIT software. Fluid flow and heat transfer are simulated and results compared using both laminar and turbulent flow models k-, and SST k-omega, with steady-state solvers to calculate pressure drop, flow, and temperature fields. Model validation is carried out by comparing the simulated value friction factor f and Colburn factor j to experimental results investigate by Wang. Reasonable agreement is found between the simulations and experimental data, and the fluent software has been sufficient for simulating the flow fields in tube-fin heat exchangers.

  5. Thermal design heat sinks, thermoelectrics, heat pipes, compact heat exchangers, and solar cells

    CERN Document Server

    Lee, H S

    2010-01-01

    The proposed is written as a senior undergraduate or the first-year graduate textbook,covering modern thermal devices such as heat sinks, thermoelectric generators and coolers, heat pipes, and heat exchangers as design components in larger systems. These devices are becoming increasingly important and fundamental in thermal design across such diverse areas as microelectronic cooling, green or thermal energy conversion, and thermal control and management in space, etc. However, there is no textbook available covering this range of topics. The proposed book may be used as a capstone design cours

  6. Process Heat Exchanger Options for the Advanced High Temperature Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwall; Eung Soo Kim; Michael McKellar; Nolan Anderson

    2011-06-01

    The work reported herein is a significant intermediate step in reaching the final goal of commercial-scale deployment and usage of molten salt as the heat transport medium for process heat applications. The primary purpose of this study is to aid in the development and selection of the required heat exchanger for power production and process heat application, which would support large-scale deployment.

  7. Process Heat Exchanger Options for Fluoride Salt High Temperature Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwall; Eung Soo Kim; Michael McKellar; Nolan Anderson

    2011-04-01

    The work reported herein is a significant intermediate step in reaching the final goal of commercial-scale deployment and usage of molten salt as the heat transport medium for process heat applications. The primary purpose of this study is to aid in the development and selection of the required heat exchanger for power production and process heat application, which would support large-scale deployment.

  8. Heat pipe heat exchanger and its potential to energy recovery in the tropics

    Directory of Open Access Journals (Sweden)

    Yau Yat H.

    2015-01-01

    Full Text Available The heat recovery by the heat pipe heat exchangers was studied in the tropics. Heat pipe heat exchangers with two, four, six, and eight numbers of rows were examined for this purpose. The coil face velocity was set at 2 m/s and the temperature of return air was kept at 24°C in this study. The performance of the heat pipe heat exchangers was recorded during the one week of operation (168 hours to examine the performance data. Then, the collected data from the one week of operation were used to estimate the amount of energy recovered by the heat pipe heat exchangers annually. The effect of the inside design temperature and the coil face velocity on the energy recovery for a typical heat pipe heat exchanger was also investigated. In addition, heat pipe heat exchangers were simulated based on the effectiveness-NTU method, and their theoretical values for the thermal performance were compared with the experimental results.

  9. Heat Pipe Heat Exchangers with Double Isolation Layers for Prevention of Interpath Leakage Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Cooling Technologies, Inc. (ACT), supported by Hamilton Sundstrand, proposes to develop a heat pipe heat exchanger that is low mass and provides two levels...

  10. Heat Pipe Heat Exchangers with Double Isolation Layers for Prevention of Interpath Leakage Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current manned spacecraft heat rejection systems use two heat exchangers and an intermediate fluid loop to provide isolation between the crew compartment air and the...

  11. On Effectiveness and Entropy Generatioin in Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    XiongDaxi; LiZhixin; 等

    1996-01-01

    Some conceptual problems were discussed in the present paper,Firstly,according to the physical meaning of effectiveness,a new expression of effectiveness was developed by using an ideal heat exchnager model and temperature histogram method,in which the non-uniform inlet temperature profile was considered.Secondly,the relation of entropy generation number to effectiveness was studied,it was pointed out that both of them could express the perfect degree of a heat exchanger to the second thermodynamic law.Finally,to describe both quantity and quality of heat transferred in a heat exchanger a criterion named as comperhensive thermal performance coefficient (CTPE) was presented.

  12. Nosehouse: heat-conserving ventilators based on nasal counterflow exchangers.

    Science.gov (United States)

    Vogel, Steven

    2009-12-01

    Small birds and mammals commonly minimize respiratory heat loss with reciprocating counterflow exchangers in their nasal passageways. These animals extract heat from the air in an exhalation to warm those passageways and then use that heat to warm the subsequent inhalation. Although the near-constant volume of buildings precludes direct application of the device, a pair of such exchangers located remotely from each other circumvents that problem. A very simple and crudely constructed small-scale physical model of the device worked well enough as a heat conserver to suggest utility as a ventilator for buildings.

  13. New latent heat storage system with nanoparticles for thermal management of electric vehicles

    Science.gov (United States)

    Javani, N.; Dincer, I.; Naterer, G. F.

    2014-12-01

    In this paper, a new passive thermal management system for electric vehicles is developed. A latent heat thermal energy storage with nanoparticles is designed and optimized. A genetic algorithm method is employed to minimize the length of the heat exchanger tubes. The results show that even the optimum length of a shell and tube heat exchanger becomes too large to be employed in a vehicle. This is mainly due to the very low thermal conductivity of phase change material (PCM) which fills the shell side of the heat exchanger. A carbon nanotube (CNT) and PCM mixture is then studied where the probability of nanotubes in a series configuration is defined as a deterministic design parameter. Various heat transfer rates, ranging from 300 W to 600 W, are utilized to optimize battery cooling options in the heat exchanger. The optimization results show that smaller tube diameters minimize the heat exchanger length. Furthermore, finned tubes lead to a higher heat exchanger length due to more heat transfer resistance. By increasing the CNT concentration, the optimum length of the heat exchanger decreases and makes the improved thermal management system a more efficient and competitive with air and liquid thermal management systems.

  14. High Effectiveness Heat Exchanger for Cryogenic Refrigerators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose an innovative high performance cryogenic heat exchanger manufactured of titanium by photo-etching and diffusion bonding. This is a parallel plate design...

  15. Phase Change Material (PCM) Heat Exchanger Development Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Project has identified two PCM HX concepts that will be designed, developed and demonstrated on-board the International Space Station (ISS):The first heat exchanger...

  16. 1-MWE heat exchangers for OTEC. Final design report

    Energy Technology Data Exchange (ETDEWEB)

    Sprouse, A.M.

    1980-06-19

    The design of a 1 MWe OTEC heat exchanger is documented, including the designs of the evaporator and associated systems, condenser, instrumentation, and materials for corrosion/erosion control and fabrication processes. (LEW)

  17. Heat exchanger identification by using iterative fuzzy observers

    Science.gov (United States)

    Lalot, Sylvain; Guðmundsson, Oddgeir; Pálsson, Halldór; Pálsson, Ólafur Pétur

    2016-05-01

    The principle of fuzzy observers is first illustrated on a general example: the determination of the two parameters of second order systems using a step response. The set of equations describing the system are presented and it is shown that accurate results are obtained, even for a high level of noise. The heat exchanger model is then introduced. It is based on a spatial division of a counter flow heat exchanger into multiple sections. The governing equations are rewritten as a state space representation. The number of sections needed to get accurate results is determined by comparing estimated values to experimental data. Based on the mean value of the root mean squared errors, it is shown that 80 sections is an appropriate value for this heat exchanger. It is then shown that the iterative fuzzy observers can be used to determine the main parameters of the counter flow heat exchanger, i.e. the convection heat transfer coefficients, when in transient state. The final values of these parameters are heat transfer coefficient corresponds to a ±0.5 % variation of the estimated overall heat transfer coefficient. This study also shows that the fuzzy observers are equally efficient when the heat exchanger is in steady state.

  18. Analysis of the Technological Parameters of the Heat Exchanger in the Heating Pipe

    Directory of Open Access Journals (Sweden)

    Knyazev Vladimir

    2017-01-01

    Full Text Available The main purpose of this article is to analyze the selecting of technological parameters for the heat exchanger to improve the heat transfer and reduce the noise during operation in the heating pipe, which is used in the different systems of the planes and helicopters. In result of this study, the best technical parameters are found, considering different variations of deformation cutting heat exchanger pipes.

  19. Oil Circulation Effects on Evaporation Heat Transfer in Brazed Plate Heat Exchanger using R134A

    OpenAIRE

    Jang, Jaekyoo; Chang, Youngsoo; Kang, Byungha

    2012-01-01

    Experimental study was performed for oil circulation effects on evaporation heat transfer in the brazed type plate heat exchangers using R134A. In this study, distribution device was installed to ensure uniform flow distribution in the refrigerant flow passage, which enhances heat transfer performance of plate type heat exchanger. Tests were conducted for three evaporation temperature; 33℃, 37℃, and 41℃ and several oil circulation conditions. The nominal conditions of refrigerant are as follo...

  20. Experimental and Numerical Comparison of Two Borehole Heat Exchangers

    DEFF Research Database (Denmark)

    Alberdi Pagola, Maria; Poulsen, Søren Erbs

    2014-01-01

    This report outlines key results from a comparative study of two different pipe borehole heat exchanger (BHE) configurations. The work was carried out by VIA University College and in collaboration with GM Plast A/S.......This report outlines key results from a comparative study of two different pipe borehole heat exchanger (BHE) configurations. The work was carried out by VIA University College and in collaboration with GM Plast A/S....

  1. Fin Distance Effect at Tube-Fin Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Frana K.

    2013-04-01

    Full Text Available Article deals with numerical simulation of the Tube-Fin heat exchanger. Several distances between fins are examined with intence of increasing the cooling output of the heat exchanger. Geometrical model consists of set of 2 fins with input and output area. Calculations covers the area of the gap from 2.25 mm to 4 mm with new fin geometry. For the numerical silumation was used software Ansys Fluent.

  2. Fin Distance Effect at Tube-Fin Heat Exchanger

    Science.gov (United States)

    Lemfeld, F.; Muller, M.; Frana, K.

    2013-04-01

    Article deals with numerical simulation of the Tube-Fin heat exchanger. Several distances between fins are examined with intence of increasing the cooling output of the heat exchanger. Geometrical model consists of set of 2 fins with input and output area. Calculations covers the area of the gap from 2.25 mm to 4 mm with new fin geometry. For the numerical silumation was used software Ansys Fluent.

  3. Thermal performance modeling of cross-flow heat exchangers

    CERN Document Server

    Cabezas-Gómez, Luben; Saíz-Jabardo, José Maria

    2014-01-01

    This monograph introduces a numerical computational methodology for thermal performance modeling of cross-flow heat exchangers, with applications in chemical, refrigeration and automobile industries. This methodology allows obtaining effectiveness-number of transfer units (e-NTU) data and has been used for simulating several standard and complex flow arrangements configurations of cross-flow heat exchangers. Simulated results have been validated through comparisons with results from available exact and approximate analytical solutions. Very accurate results have been obtained over wide ranges

  4. A fundamentally new approach to air-cooled heat exchangers.

    Energy Technology Data Exchange (ETDEWEB)

    Koplow, Jeffrey P.

    2010-01-01

    We describe breakthrough results obtained in a feasibility study of a fundamentally new architecture for air-cooled heat exchangers. A longstanding but largely unrealized opportunity in energy efficiency concerns the performance of air-cooled heat exchangers used in air conditioners, heat pumps, and refrigeration equipment. In the case of residential air conditioners, for example, the typical performance of the air cooled heat exchangers used for condensers and evaporators is at best marginal from the standpoint the of achieving maximum the possible coefficient of performance (COP). If by some means it were possible to reduce the thermal resistance of these heat exchangers to a negligible level, a typical energy savings of order 30% could be immediately realized. It has long been known that a several-fold increase in heat exchanger size, in conjunction with the use of much higher volumetric flow rates, provides a straight-forward path to this goal but is not practical from the standpoint of real world applications. The tension in the market place between the need for energy efficiency and logistical considerations such as equipment size, cost and operating noise has resulted in a compromise that is far from ideal. This is the reason that a typical residential air conditioner exhibits significant sensitivity to reductions in fan speed and/or fouling of the heat exchanger surface. The prevailing wisdom is that little can be done to improve this situation; the 'fan-plus-finned-heat-sink' heat exchanger architecture used throughout the energy sector represents an extremely mature technology for which there is little opportunity for further optimization. But the fact remains that conventional fan-plus-finned-heat-sink technology simply doesn't work that well. Their primary physical limitation to performance (i.e. low thermal resistance) is the boundary layer of motionless air that adheres to and envelops all surfaces of the heat exchanger. Within this

  5. Brazed aluminum, Plate-fin heat exchangers for OTEC

    Energy Technology Data Exchange (ETDEWEB)

    Foust, H.D.

    1980-12-01

    Brazed aluminum plate-fin heat exchangers have been available for special applications for over thirty years. The performance, compactness, versatility, and low cost of these heat exchangers has been unequaled by other heat exchanger configuration. The application of brazed aluminum has been highly limited because of necessary restrictions for clean non-corrosive atmospheres. Air and gas separation have provided ideal conditions for accepting brazed aluminum and in turn have benefited by the salient features of these plate-fin heat exchangers. In fact, brazed aluminum and cryogenic gas and air separation have become nearly synonymous. Brazed aluminum in its historic form could not be considered for a seawater atmosphere. However, technology presents a new look of significant importance to OTEC in terms of compactness and cost. The significant technological variation made was to include one-piece hollow extensions for the seawater passages. Crevice corrosion sites are thereby entirely eliminated and pitting corrosion attack will be controlled by an integral and sacrificial layer of a zinc-aluminum alloy. This paper on brazed aluminum plate-fin heat exchangers for OTEC will aquaint the reader with the state-of-art and variations suggested to qualify this form of aluminum for seawater use. In order to verify the desirable cost potential for OTEC, Trane teamed with Westinghouse to perform an OTEC system analysis with this heat exchanger. These results are very promising and reported in detail elsewhere.

  6. Heat transfer, condensation and fog formation in crossflow plastic heat exchangers

    NARCIS (Netherlands)

    Brouwers, H.J.H.; Geld, van der C.W.M.

    1996-01-01

    In this paper heat transfer of air-water-vapour mixtures in plastic crossflow heat exchangers is studied theoretically and experimentally. First, a model for heat transfer without condensation is derived, resulting in a set of classical differential equations. Subsequently, heat transfer with wall c

  7. Thermal behavior of a heat exchanger module for seasonal heat storage

    DEFF Research Database (Denmark)

    Fan, Jianhua; Furbo, Simon; Andersen, Elsa;

    2012-01-01

    Experimental and theoretic investigations are carried out to study the heat transfer capacity rate of a heat exchanger module for seasonal heat storage with sodium acetate trihydrate (SAT) supercooling in a stable way. A sandwich heat storage test module has been built with the phase change...... material (PCM) storage box in between two plate heat exchangers. Charge of the PCM storage is investigated experimentally with solid phase SAT as initial condition. Discharge of the PCM storage with the presence of crystallization is studied experimentally. Fluid flow and heat transfer in the PCM module...... are theoretically investigated by Computational Fluid Dynamics (CFD) calculations. The heat transfer rates between the PCM storage and the heating fluid/cooling fluid in the plate heat exchangers are determined. The CFD calculated temperatures are compared to measured temperatures. Based on the studies...

  8. Assessment of ASME code examinations on regenerative, letdown and residual heat removal heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Gosselin, Stephen R.; Cumblidge, Stephen E.; Anderson, Michael T.; Simonen, Fredric A.; Tinsley, G. A.; Lydell, B.; Doctor, Steven R.

    2005-07-01

    Inservice inspection requirements for pressure retaining welds in the regenerative, letdown, and residual heat removal heat exchangers are prescribed in Section XI Articles IWB and IWC of the ASME Boiler and Pressure Vessel Code. Accordingly, volumetric and/or surface examinations are performed on heat exchanger shell, head, nozzle-to-head, and nozzle-to-shell welds. Inspection difficulties associated with the implementation of these Code-required examinations have forced operating nuclear power plants to seek relief from the U.S. Nuclear Regulatory Commission. The nature of these relief requests are generally concerned with metallurgical, geometry, accessibility, and radiation burden. Over 60% of licensee requests to the NRC identify significant radiation exposure burden as the principle reason for relief from the ASME Code examinations on regenerative heat exchangers. For the residual heat removal heat exchangers, 90% of the relief requests are associated with geometry and accessibility concerns. Pacific Northwest National Laboratory was funded by the NRC Office of Nuclear Regulatory Research to review current practice with regard to volumetric and/or surface examinations of shell welds of letdown heat exchangers regenerative heat exchangers and residual (decay) heat removal heat exchangers Design, operating, common preventative maintenance practices, and potential degradation mechanisms are reviewed. A detailed survey of domestic and international PWR-specific operating experience was performed to identify pressure boundary failures (or lack of failures) in each heat exchanger type and NSSS design. The service data survey was based on the PIPExp® database and covers PWR plants worldwide for the period 1970-2004. Finally a risk assessment of the current ASME Code inspection requirements for residual heat removal, letdown, and regenerative heat exchangers is performed. The results are then reviewed to discuss the examinations relative to plant safety and

  9. Entropy resistance analyses of a two-stream parallel flow heat exchanger with viscous heating

    Institute of Scientific and Technical Information of China (English)

    Cheng Xue-Tao; Liang Xin-Gang

    2013-01-01

    Heat exchangers are widely used in industry,and analyses and optimizations of the performance of heat exchangers are important topics.In this paper,we define the concept of entropy resistance based on the entropy generation analyses of a one-dimensional heat transfer process.With this concept,a two-stream parallel flow heat exchanger with viscous heating is analyzed and discussed.It is found that the minimization of entropy resistance always leads to the maximum heat transfer rate for the discussed two-stream parallel flow heat exchanger,while the minimizations of entropy generation rate,entropy generation numbers,and revised entropy generation number do not always.

  10. Heat exchanger selection and design analyses for metal hydride heat pump systems

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Voskuilen, Tyler G.; Waters, Essene L.

    2016-01-01

    This study presents a design analysis for the development of highly efficient heat exchangers within stationary metal hydride heat pumps. The design constraints and selected performance criteria are applied to three representative heat exchangers. The proposed thermal model can be applied to select...... the most efficient heat exchanger design and provides outcomes generally valid in a pre-design stage. Heat transfer effectiveness is the principal performance parameter guiding the selection analysis, the results of which appear to be mildly (up to 13%) affected by the specific Nusselt correlation used....... The thermo-physical properties of the heat transfer medium and geometrical parameters are varied in the sensitivity analysis, suggesting that the length of independent tubes is the physical parameter that influences the performance of the heat exchangers the most. The practical operative regions for each...

  11. Sprinkled Heat Exchangers in Evaporation Mode

    Directory of Open Access Journals (Sweden)

    Pospisil J.

    2013-04-01

    Full Text Available The paper presents research on the heat transfer at sprinkled tube bundles situated in a test chamber at atmospheric pressure and low-pressure. Dynamic effects of physical quantities influencing the heat transfer coefficient during boiling are examined experimentally. Experimental results were achieved by means of balance measuring using thermocouple probes and by analysis of thermal diagrams created during operation periods.

  12. CFD as a Design Tool for a Concentric Heat Exchanger

    NARCIS (Netherlands)

    Oosterhuis, J.P.; Bühler, S.; wilcox, D; Meer, van der T.H.

    2012-01-01

    A concentric gas-to-gas heat exchanger is designed for application as a recuperator in the domestic boiler industry. The recuperator recovers heat from the exhaust gases of a combustion process to preheat the ingoing gaseous fuel mixture resulting in increased fuel efficiency. This applied study sho

  13. A structured approach to heat exchanger network retrofit design

    NARCIS (Netherlands)

    Van Reisen, J.L.B.

    2008-01-01

    Process plants have high energy consumption. Much energy can be saved by a proper design of the heat exchanger network, which contains the main heat transferring equipment of the plant. Existing plants can often be made more energy-efficient by a retrofit: the (physical) modification of the equipmen

  14. Capillary pumped loop body heat exchanger

    Science.gov (United States)

    Swanson, Theodore D. (Inventor); Wren, deceased, Paul (Inventor)

    1998-01-01

    A capillary pumped loop for transferring heat from one body part to another body part, the capillary pumped loop comprising a capillary evaporator for vaporizing a liquid refrigerant by absorbing heat from a warm body part, a condenser for turning a vaporized refrigerant into a liquid by transferring heat from the vaporized liquid to a cool body part, a first tube section connecting an output port of the capillary evaporator to an input of the condenser, and a second tube section connecting an output of the condenser to an input port of the capillary evaporator. A wick may be provided within the condenser. A pump may be provided between the second tube section and the input port of the capillary evaporator. Additionally, an esternal heat source or heat sink may be utilized.

  15. Heat Transfer Analysis of Passive Residual Heat Removal Heat Exchanger under Natural Convection Condition in Tank

    Directory of Open Access Journals (Sweden)

    Qiming Men

    2014-01-01

    Full Text Available Aiming at the heat transfer calculation of the Passive Residual Heat Removal Heat Exchanger (PRHR HX, experiments on the heat transfer of C-shaped tube immerged in a water tank were performed. Comparisons of different correlation in literatures with the experimental data were carried out. It can be concluded that the Dittus-Boelter correlation provides a best-estimate fit with the experimental results. The average error is about 0.35%. For the tube outside, the McAdams correlations for both horizontal and vertical regions are best-estimated. The average errors are about 0.55% for horizontal region and about 3.28% for vertical region. The tank mixing characteristics were also investigated in present work. It can be concluded that the tank fluid rose gradually which leads to a thermal stratification phenomenon.

  16. Analysis of heat exchanger network for temperature fluctuation

    Directory of Open Access Journals (Sweden)

    Jin Zunlong

    2015-09-01

    Full Text Available Subject to temperature disturbance, exchangers in heat exchanger network will interact. It is necessary to evaluate the degree of temperature fluctuation in the network. There is inherently linear relationship between output and inlet temperatures of heat exchanger network. Based on this, the concept of temperature-change sensitivity coefficient was put forward. Quantitative influence of temperature fluctuation in the network was carried out in order to examine transmission character of temperature fluctuation in the system. And the information was obtained for improving the design quality of heat exchanger network. Favorable results were obtained by the introduced method compared with the experimental results. These results will assist engineers to distinguish primary and secondary influencing factors, which can be used in observing and controlling influencing factors accurately.

  17. Performance Prediction of Cross-finned Tube Heat Exchangers

    Science.gov (United States)

    Kondou, Chieko; Senshu, Takao; Matsumura, Kenji; Oguni, Kensaku

    An important issue in heat pumps is increasing their efficiency, in order to achieve a significant optimization for heat exchangers. Techniques to simulate the flow length averaged heat transfer coefficient and static pressure drop through the flow passage are presented in this paper. In addition, an analytical evaluation of the cost reduction for a cross-fined tube heat exchanger of outdoor heat pump units is instantiated. The dimensionless factors, Colburn's factor j and Fanning's friction factor f, express the heat transfer performance and frictional characteristics, as a function of Reynolds number. These depend on slit possession, an original parameter used in this study. Further, this paper describes an approximate expression of the fin efficiency, which can be used for to survey the fin parameters. The above three concepts were necessary to forecast the performance on the airside. In the results, the cost minimum point was obtained with a comparable performance.

  18. Compact interior heat exchangers for CO{sub 2} mobile heat pumping systems

    Energy Technology Data Exchange (ETDEWEB)

    Hafner, Armin

    2003-07-01

    The natural refrigerant carbon dioxide (CO{sub 2}) offers new possibilities for design of flexible, efficient and environmentally safe mobile heat pumping systems. As high-efficient car engines with less waste heat are developed, extra heating of the passenger compartment is needed in the cold season. A reversible transcritical CO{sub 2} system with gliding temperature heat rejection can give high air delivery temperature which results in rapid heating of the passenger compartment and rapid defogging or defrosting of windows. When operated in cooling mode, the efficiency of transcritical CO{sub 2} systems is higher compared to common (HFC) air conditioning systems, at most dominant operating conditions. Several issues were identified for the design of compact interior heat exchangers for automotive reversible CO{sub 2} heat pumping systems. Among theses issues are: (1) Refrigerant flow distribution, (2) Heat exchanger fluid flow circuiting, (3) Air temperature uniformity downstream of the heat exchanger, (4) Minimization of temperature approach, (5) Windshield flash fogging due to retained water inside the heat exchanger, (6) Internal beat conduction in heating mode operation, and (7) Refrigerant side pressure drop In order to provide a basis for understanding these issues, the author developed a calculation model and set up a test facility and investigated different prototype heat exchangers experimentally.

  19. Characteristics of Vertical Mantle Heat Exchangers for Solar Water Heaters

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Morrison, G.L.; Behnia, M.

    1999-01-01

    - The flow structure in vertical mantle heat exchangers was investigated using a full-scale tank designed to facilitate flow visualisation. The flow structure and velocities in the mantle were measured using a particle Image Velocimetry (PIV) system. A CFD simulation model of vertical mantle heat...... exchangers was also developed for detailed evaluation of the heat flux distribution over the mantle surface. Both the experimental and simulation results indicate that distribution of the flow around the mantle gap is governed by buoyancy driven recirculation in the mantle. The operation of the mantle...

  20. Finned tubes for heat exchangers: Characterization and performance simulation

    Energy Technology Data Exchange (ETDEWEB)

    Armand, J.-L.; Molle, N. (Centre Tecnique des Industries Aerauliques et Thermiques (CETIAT), 75 Paris (France))

    1992-06-01

    Relevant to air conditioning applications, the state-of-the-art of finned tube heat exchanger design is reviewed. The review covers the key design, performance and operation characteristics, as well as, principal heat transfer correlations for exchangers adopting 'dry' (without condensation) and 'wet' operation. External side heat transfer and pressure drop calculation methods are established for the characterization of external surfaces. For internal surfaces, correlations are given for two-phase flow and pressure drop. Reference is made to the NTU and CANUT simulation codes for the determination of optimum finned tube geometries for standard and particular operating conditions.

  1. Optimization of Heat Exchangers for Intercooled Recuperated Aero Engines

    Directory of Open Access Journals (Sweden)

    Dimitrios Misirlis

    2017-03-01

    Full Text Available In the framework of the European research project LEMCOTEC, a section was devoted to the further optimization of the recuperation system of the Intercooled Recuperated Aero engine (IRA engine concept, of MTU Aero Engines AG. This concept is based on an advanced thermodynamic cycle combining both intercooling and recuperation. The present work is focused only on the recuperation process. This is carried out through a system of heat exchangers mounted inside the hot-gas exhaust nozzle, providing fuel economy and reduced pollutant emissions. The optimization of the recuperation system was performed using computational fluid dynamics (CFD computations, experimental measurements and thermodynamic cycle analysis for a wide range of engine operating conditions. A customized numerical tool was developed based on an advanced porosity model approach. The heat exchangers were modeled as porous media of predefined heat transfer and pressure loss behaviour and could also incorporate major and critical heat exchanger design decisions in the CFD computations. The optimization resulted in two completely new innovative heat exchanger concepts, named as CORN (COnical Recuperative Nozzle and STARTREC (STraight AnnulaR Thermal RECuperator, which provided significant benefits in terms of fuel consumption, pollutants emission and weight reduction compared to more conventional heat exchanger designs, thus proving that further optimization potential for this technology exists.

  2. Laminar fluid flow and heat transfer in a fin-tube heat exchanger with vortex generators

    Energy Technology Data Exchange (ETDEWEB)

    Yanagihara, J.I.; Rodriques, R. Jr. [Polytechnic School of Univ. of Sao Paolo, Sao Paolo (Brazil). Dept. of Mechanical Engineering

    1996-12-31

    Development of heat transfer enhancement techniques for fin-tube heat exchangers has great importance in industry. In recent years, heat transfer augmentation by vortex generators has been considered for use in plate fin-tube heat exchangers. The present work describes a numerical investigation about the influence of delta winglet pairs of vortex generators on the flow structure and heat transfer of a plate fin-tube channel. The Navier-Stokes and Energy equations are solved by the finite volume method using a boundary-fitted coordinate system. The influence of vortex generators parameters such as position, angle of attack and aspect ratio were investigated. Local and global influences of vortex generators in heat transfer and flow losses were analyzed by comparison with a model using smooth fin. The results indicate great advantages of this type of geometry for application in plate fin-tube heat exchangers, in terms of large heat transfer enhancement and small pressure loss penalty. (author)

  3. The Effect of Sink Temperature on a Capillary Pumped Loop Employing a Flat Evaporator and Shell and Tube Condenser

    Energy Technology Data Exchange (ETDEWEB)

    M. Cerza; R.C. Herron; J.J. Harper

    2002-06-24

    An experimental facility for conducting research on capillary pumped loop (CPL) systems was developed. In order to simulate shipboard cooling water encountered at various locations of the ocean, the heat sink temperature of the facility could be varied. A flat plate, CPL evaporator was designed and tested under various heat sink temperatures. The sink temperature ranged from 274.3 to 305.2 K and the heat input varied from 250 to 800 W which corresponds to heat fluxes up to 1.8 W/cm{sup 2}. The CPL flat plate evaporator performed very well under this range of heat input and sink temperatures. The main result obtained showed that a large degree of subcooling developed between the evaporator vapor outlet line and liquid return line. This condensate depression increased with increasing heat input.

  4. Optimizing the Heat Exchanger Network of a Steam Reforming System

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh; Korsgaard, Anders Risum; Kær, Søren Knudsen

    2004-01-01

    Proton Exchange Membrane (PEM) based combined heat and power production systems are highly integrated energy systems. They may include a hydrogen production system and fuel cell stacks along with post combustion units optionally coupled with gas turbines. The considered system is based on a natural...... stationary numerical system model was used and process integration techniques for optimizing the heat exchanger network for the reforming unit are proposed. Objective is to minimize the system cost. Keywords: Fuel cells; Steam Reforming; Heat Exchanger Network (HEN) Synthesis; MINLP....... gas steam reformer along with gas purification reactors to generate clean hydrogen suited for a PEM stack. The temperatures in the various reactors in the fuel processing system vary from around 1000°C to the stack temperature at 80°C. Furthermore, external heating must be supplied to the endothermic...

  5. Performance of parallel flow HeII heat exchangers

    Science.gov (United States)

    Huang, Y.; Chang, Y.; Witt, R. J.; Van Sciver, S. W.

    Previous studies of HeII heat exchangers have focused on tube-in-shell designs. The present paper examines the properties of a parallel flow HeII heat exchanger formed from two 254 mm lengths of copper channel having nominal rectangular dimensions 2 mm × 4 mm. Heaters positioned at the inlets and outlets of both channels permit the simulation of a variety of physically plausible boundary conditions. An iterative numerical method, based on one-dimensional energy balances in each channel with coupling through a heat transfer term, is presented and agrees well with the experimental results. As with tube-in-shell designs, parallel flow HeII heat exchangers may exhibit unusual temperature profiles.

  6. Boiling heat transfer of refrigerant R-21 in upward flow in plate-fin heat exchanger

    Science.gov (United States)

    Kuznetsov, V. V.; Shamirzaev, A. S.

    2015-11-01

    The article presents the results of experimental investigation of boiling heat transfer of refrigerant R-21 in upward flow in a vertical plate-fin heat exchanger with transverse size of the channels that is smaller than the capillary constant. The heat transfer coefficients obtained in ranges of small mass velocities and low heat fluxes, which are typical of the industry, have been poorly studied yet. The characteristic patterns of the upward liquid-vapor flow in the heat exchanger channels and the regions of their existence are detected. The obtained data show a weak dependence of heat transfer coefficient on equilibrium vapor quality, mass flow rate, and heat flux density and do not correspond to calculations by the known heat transfer models. A possible reason for this behavior is a decisive influence of evaporation of thin liquid films on the heat transfer at low heat flux.

  7. Heat exchangers selection, rating, and thermal design

    CERN Document Server

    Kakaç, Sadik; Pramuanjaroenkij, Anchasa

    2012-01-01

    Praise for the Bestselling Second EditionThe first edition of this work gathered in one place the essence of important information formerly scattered throughout the literature. The second edition adds the following new information: introductory material on heat transfer enhancement; an application of the Bell-Delaware method; new correlation for calculating heat transfer and friction coefficients for chevron-type plates; revision of many of the solved examples and the addition of several new ones.-MEMagazine

  8. Intensification of heat and mass transfer by ultrasound: application to heat exchangers and membrane separation processes.

    Science.gov (United States)

    Gondrexon, N; Cheze, L; Jin, Y; Legay, M; Tissot, Q; Hengl, N; Baup, S; Boldo, P; Pignon, F; Talansier, E

    2015-07-01

    This paper aims to illustrate the interest of ultrasound technology as an efficient technique for both heat and mass transfer intensification. It is demonstrated that the use of ultrasound results in an increase of heat exchanger performances and in a possible fouling monitoring in heat exchangers. Mass transfer intensification was observed in the case of cross-flow ultrafiltration. It is shown that the enhancement of the membrane separation process strongly depends on the physico-chemical properties of the filtered suspensions.

  9. Heat recovery from Diesel exhausts by means of a fluidized bed heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Carlomagno, G.M.; Festa, R.; Massimilla, L.

    1983-01-01

    A fluidized bed heat exchanger, equipped with a specially designed manifold gas distributor, is conveniently used to recover heat from exhausts of a 60 kW Diesel engine. The sensitivity of the bed to tube heat transfer coefficient to soot fouling and the sensitivity of the exchanger efficiency to variations of such coefficients are analyzed. Procedures for in-operation tube defouling are described.

  10. Progress Report for Diffusion Welding of the NGNP Process Application Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    R.E. Mizia; D.E. Clark; M.V. Glazoff; T.E. Lister; T.L. Trowbridge

    2011-04-01

    The NGNP Project is currently investigating the use of metallic, diffusion welded, compact heat exchangers to transfer heat from the primary (reactor side) heat transport system to the secondary heat transport system. The intermediate heat exchanger will transfer this heat to downstream applications such as hydrogen production, process heat, and electricity generation. The channeled plates that make up the heat transfer surfaces of the intermediate heat exchanger will have to be assembled into an array by diffusion welding.

  11. Geothermal heat exchanger with coaxial flow of fluids

    Directory of Open Access Journals (Sweden)

    Pejić Dragan M.

    2005-01-01

    Full Text Available The paper deals with a heat exchanger with coaxial flow. Two coaxial pipes of the secondary part were placed directly into a geothermal boring in such a way that geothermal water flows around the outer pipe. Starting from the energy balance of the exchanger formed in this way and the assumption of a study-state operating regime, a mathematical model was formulated. On the basis of the model, the secondary circle output temperature was determined as a function of the exchanger geometry, the coefficient of heat passing through the heat exchange areas, the average mass isobaric specific heats of fluid and mass flows. The input temperature of the exchanger secondary circle and the temperature of the geothermal water at the exit of the boring were taken as known values. Also, an analysis of changes in certain factors influencing the secondary water temperature was carried out. The parameters (flow temperature of the deep boring B-4 in Sijarinska Spa, Serbia were used. The theoretical results obtained indicate the great potential of this boring and the possible application of such an exchanger.

  12. CFD analysis of the plate heat exchanger - Mathematical modelling of mass and heat transfer in serial connection with tubular heat exchanger

    Science.gov (United States)

    Bojko, Marian; Kocich, Radim

    2016-06-01

    Application of numerical simulations based on the CFD calculation when the mass and heat transfer between the fluid flows is essential component of thermal calculation. In this article the mathematical model of the heat exchanger is defined, which is subsequently applied to the plate heat exchanger, which is connected in series with the other heat exchanger (tubular heat exchanger). The present contribution deals with the possibility to use the waste heat of the flue gas produced by small micro turbine. Inlet boundary conditions to the mathematical model of the plate heat exchanger are obtained from the results of numerical simulation of the tubular heat exchanger. Required parameters such for example inlet temperature was evaluated from temperature field, which was subsequently imported to the inlet boundary condition to the simulation of plate heat exchanger. From the results of 3D numerical simulations are evaluated basic flow variables including the evaluation of dimensionless parameters such as Colburn j-factor and friction ft factor. Numerical simulation is realized by software ANSYS Fluent15.0.

  13. Numerical evaluation of plate heat exchanger performance in geothermal district heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, T. [Iceland Univ., Reykjavik (Iceland)

    1996-12-31

    This paper describes the performance of plate heat exchangers in residential water radiator heating systems receiving their heat from geothermal resources. Radiator theory is reviewed and determination of annual hot water requirements for space heating is discussed. Performance evaluation is made of plate heat exchangers and results obtained by means of two equations commonly used for this purpose, the Sieder-Tate and the Dittus-Boelter equations, compared to results obtained with a simplified equation where heat transfer in the heat exchanger is assumed to depend only on the fluid mass flow on both sides. It is found that for prevailing temperature ranges in Icelandic geothermal systems the mass pow approximation gives results very close to those determined by the more complicated conventional equations. (UK)

  14. Analysis of radiative heat transfer impact in cross-flow tube and fin heat exchangers

    Directory of Open Access Journals (Sweden)

    Hanuszkiewicz-Drapała Małgorzata

    2016-03-01

    Full Text Available A cross-flow, tube and fin heat exchanger of the water – air type is the subject of the analysis. The analysis had experimental and computational form and was aimed for evaluation of radiative heat transfer impact on the heat exchanger performance. The main element of the test facility was an enlarged recurrent segment of the heat exchanger under consideration. The main results of measurements are heat transfer rates, as well as temperature distributions on the surface of the first fin obtained by using the infrared camera. The experimental results have been next compared to computational ones coming from a numerical model of the test station. The model has been elaborated using computational fluid dynamics software. The computations have been accomplished for two cases: without radiative heat transfer and taking this phenomenon into account. Evaluation of the radiative heat transfer impact in considered system has been done by comparing all the received results.

  15. Analysis of radiative heat transfer impact in cross-flow tube and fin heat exchangers

    Science.gov (United States)

    Hanuszkiewicz-Drapała, Małgorzata; Bury, Tomasz; Widziewicz, Katarzyna

    2016-03-01

    A cross-flow, tube and fin heat exchanger of the water - air type is the subject of the analysis. The analysis had experimental and computational form and was aimed for evaluation of radiative heat transfer impact on the heat exchanger performance. The main element of the test facility was an enlarged recurrent segment of the heat exchanger under consideration. The main results of measurements are heat transfer rates, as well as temperature distributions on the surface of the first fin obtained by using the infrared camera. The experimental results have been next compared to computational ones coming from a numerical model of the test station. The model has been elaborated using computational fluid dynamics software. The computations have been accomplished for two cases: without radiative heat transfer and taking this phenomenon into account. Evaluation of the radiative heat transfer impact in considered system has been done by comparing all the received results.

  16. Temperatures and Heat Flows in a Soil Enclosing a Slinky Horizontal Heat Exchanger

    OpenAIRE

    Pavel Neuberger; Radomír Adamovský; Michaela Šeďová

    2014-01-01

    Temperature changes and heat flows in soils that host “slinky”-type horizontal heat exchangers are complex, but need to be understood if robust quantification of the thermal energy available to a ground-source heat pump is to be achieved. Of particular interest is the capacity of the thermal energy content of the soil to regenerate when the heat exchangers are not operating. Analysis of specific heat flows and the specific thermal energy regime within the soil, including that captured by the ...

  17. Liquid Salt Heat Exchanger Technology for VHTR Based Applications

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Mark; Sridhara, Kumar; Allen, Todd; Peterson, Per

    2012-10-11

    The objective of this research is to evaluate performance of liquid salt fluids for use as a heat carrier for transferring high-temperature process heat from the very high-temperature reactor (VHTR) to chemical process plants. Currently, helium is being considered as the heat transfer fluid; however, the tube size requirements and the power associated with pumping helium may not be economical. Recent work on liquid salts has shown tremendous potential to transport high-temperature heat efficiently at low pressures over long distances. This project has two broad objectives: To investigate the compatibility of Incoloy 617 and coated and uncoated SiC ceramic composite with MgCl2-KCl molten salt to determine component lifetimes and aid in the design of heat exchangers and piping; and, To conduct the necessary research on the development of metallic and ceramic heat exchangers, which are needed for both the helium-to-salt side and salt-to-process side, with the goal of making these heat exchangers technologically viable. The research will consist of three separate tasks. The first task deals with material compatibility issues with liquid salt and the development of techniques for on-line measurement of corrosion products, which can be used to measure material loss in heat exchangers. Researchers will examine static corrosion of candidate materials in specific high-temperature heat transfer salt systems and develop an in situ electrochemical probe to measure metallic species concentrations dissolved in the liquid salt. The second task deals with the design of both the intermediate and process side heat exchanger systems. Researchers will optimize heat exchanger design and study issues related to corrosion, fabrication, and thermal stresses using commercial and in-house codes. The third task focuses integral testing of flowing liquid salts in a heat transfer/materials loop to determine potential issues of using the salts and to capture realistic behavior of the salts in a

  18. A prototype heat pipe heat exchanger for the capillary pumped loop flight experiment

    Science.gov (United States)

    Ku, Jentung; Yun, Seokgeun; Kroliczek, Edward J.

    1992-01-01

    A Capillary Pumped Two-Phase Heat Transport Loop (CAPL) Flight Experiment, currently planned for 1993, will provide microgravity verification of the prototype capillary pumped loop (CPL) thermal control system for EOS. CAPL employs a heat pipe heat exchanger (HPHX) to couple the condenser section of the CPL to the radiator assembly. A prototype HPHX consisting of a heat exchanger (HX), a header heat pipe (HHP), a spreader heat pipe (SHP), and a flow regulator has been designed and tested. The HX transmits heat from the CPL condenser to the HHP, while the HHP and SHP transport heat to the radiator assembly. The flow regulator controls flow distribution among multiple parallel HPHX's. Test results indicated that the prototype HPHX could transport up to 800 watts with an overall heat transfer coefficient of more than 6000 watts/sq m-deg C. Flow regulation among parallel HPHX's was also demonstrated.

  19. Flow and Heat Transfer Simulation of Small Tube-and-Shell Heat Exchangers%小尺度管壳式换热器流动和传热数值模拟

    Institute of Scientific and Technical Information of China (English)

    洪文鹏; 辛凯

    2013-01-01

    Through symmetry simplification,the heat transfer model of small shell-and-tube heat exchanger was established; and basing on the Simple algorithm,RNG k-ε equation,porous medium model,enhanced wall function,finite volume method and the structured grid,the discrete control equation was dispersed to solve three-dimensional N-S equations and energy equations so that the heat transfer process of the fluid flow in shell can be simulated; and in the case of keeping constant tube diameter and 1.2,1.4 and 2.0 pitch diameter ratio,the distribution pattern of both flow and temperature fields was analyzed,including the key factors that affecting heat transfer pedormance.The results show that,at the same boundary conditions,the smaller pitch diameter can result in eddy current around the tube wall,this can bring higher heat transfer performance,larger turbulence intensity and tube bundle erosion which can decrease the device service life.%通过对称性简化,建立了小尺度管壳式换热器的传热模型.基于Simple算法,采用RNG k-ε方程、多孔介质模型和增强壁面函数法,结合有限体积法及结构化网格对控制方程进行离散,求解三维N-S方程和能量方程模拟了流体在壳程流动的传热过程,在管径不变的情况下,针对节径比分别为1.2、1.4和2.0下的流场及温度场的总体分布规律进行分析,对影响其传热性能的关键因素进行了探讨.结果表明:在相同边界条件下,设计较小的节径比,易在管壁周边形成涡流,换热器的传热性能指标较高,但湍流强度过大,流体剧烈冲刷管束,将对设备的寿命产生影响.

  20. Experimental investigation on heat transfer analysis of conical coil heat exchanger with 90° cone angle

    Science.gov (United States)

    Purandare, Pramod S.; Lele, Mandar M.; Gupta, Raj Kumar

    2015-03-01

    In the present study, an experimental investigation on thermal performance of the conical coil heat exchanger with 90° conical coil heat exchanger is reported. Three different conical coil heat exchangers of same mean coil diameter (Dm = 200 mm) with different tube diameters ( di = 8, 10, 12.5 mm) are analyzed under steady state condition. The analysis is carried out for the tube side hot fluid flow range of 10-100 lph ( Re = 500-5,000), while the shell side flow range of 30-90 lph. The data available from experimentation leads to evaluate heat transfer coefficients for inside and outside the tube of the conical coil heat exchanger by Wilsons plot method. The calculations are further extended to estimate Nusselt Number ( Nu) and effectiveness. The empirical correlations are proposed for predicting Nu and the outlet temperatures of hot and cold fluids. The predicted empirical correlations show reasonable agreement with the experimental results within the given range of parameters.

  1. Efficiency of Vertical Geothermal Heat Exchangers in the Ground Source Heat Pump System

    Institute of Scientific and Technical Information of China (English)

    Heyi Zeng; Nairen Diao; Zhaohong Fang

    2003-01-01

    Taking the fluid temperature distribution along the borehole depth into account, a new quasi-three-dimensional model for vertical ground heat exchangers has been established, which provides a better understanding of the heat transfer processes in the geothermal heat exchangers. On this basis the efficiency of the borehole has been defined and its analytical expression derived. Comparison with the previous two-dimensional model shows that the quasi-three-dimensional model is more rational and more accurate to depict the practical feature of the conduction of geothermal heat exchanger, and the efficiency notion can be easily used to determine the inlet and outlet temperature of the circulating fluid inside the heat exchanger.

  2. Inverse heat transfer problem in digital temperature control in plate fin and tube heat exchangers

    Science.gov (United States)

    Taler, Dawid; Sury, Adam

    2011-12-01

    The aim of the paper is a steady-state inverse heat transfer problem for plate-fin and tube heat exchangers. The objective of the process control is to adjust the number of fan revolutions per minute so that the water temperature at the heat exchanger outlet is equal to a preset value. Two control techniques were developed. The first is based on the presented mathematical model of the heat exchanger while the second is a digital proportional-integral-derivative (PID) control. The first procedure is very stable. The digital PID controller becomes unstable if the water volumetric flow rate changes significantly. The developed techniques were implemented in digital control system of the water exit temperature in a plate fin and tube heat exchanger. The measured exit temperature of the water was very close to the set value of the temperature if the first method was used. The experiments showed that the PID controller works also well but becomes frequently unstable.

  3. Development of User-Friendly Software to Design Dairy Heat Exchanger and Performance Evaluation

    Directory of Open Access Journals (Sweden)

    DipankarMandal

    2015-02-01

    Full Text Available The paper proposes a calculation algorithm and development of a software in Visual Basic(Visual Studio 2012 Express Desktop used in heat transfer studies when different heat exchangers are involved (e.g. Helical Type Triple Tube Heat Exchanger , Plate Type Heat Exchanger.It includes the easy calculation of heat transfer coefficient and followed by the design and simulation of heat exchanger design parameter by inputting general known parameters of a heat exchanger into the developed software—-―DAIRY –HE ―. A parametric study is conducted using the software interface to determine the length of tubes or dimensions of heat exchanger.

  4. Numerical Study of Condensation Heat Exchanger Design in a Saturated Pool: Correlation Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Joon [Kookmin University, Seoul (Korea, Republic of); Lee, Tae Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    Generally the condensation heat exchanger has higher heat transfer coefficient compared to the single phase heat exchanger, so has been widely applied to the cooling systems of fissile power plant. Recently vertical or horizontal type condensation heat exchangers are being studied for the application to secondary passive cooling system of nuclear plants. To design vertical condensation heat exchanger in a saturated water pool, a thermal sizing program of condensation heat exchanger, TSCON(Thermal Sizing of CONdenser) was developed. In this study, condensing heat transfer correlation of TSCON is evaluated with the existing experimental data set to design condensation heat exchanger without noncondensable gas effect (pure steam condensation)

  5. Materials, Turbomachinery and Heat Exchangers for Supercritical CO2 Systems

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Mark; Nellis, Greg; Corradini, Michael

    2012-10-19

    The objective of this project is to produce the necessary data to evaluate the performance of the supercritical carbon dioxide cycle. The activities include a study of materials compatibility of various alloys at high temperatures, the heat transfer and pressure drop in compact heat exchanger units, and turbomachinery issues, primarily leakage rates through dynamic seals. This experimental work will serve as a test bed for model development and design calculations, and will help define further tests necessary to develop high-efficiency power conversion cycles for use on a variety of reactor designs, including the sodium fast reactor (SFR) and very high-temperature gas reactor (VHTR). The research will be broken into three separate tasks. The first task deals with the analysis of materials related to the high-temperature S-CO{sub 2} Brayton cycle. The most taxing materials issues with regard to the cycle are associated with the high temperatures in the reactor side heat exchanger and in the high-temperature turbine. The system could experience pressures as high as 20MPa and temperatures as high as 650°C. The second task deals with optimization of the heat exchangers required by the S-CO{sub 2} cycle; the S-CO{sub 2} flow passages in these heat exchangers are required whether the cycle is coupled with a VHTR or an SFR. At least three heat exchangers will be required: the pre-cooler before compression, the recuperator, and the heat exchanger that interfaces with the reactor coolant. Each of these heat exchangers is unique and must be optimized separately. The most challenging heat exchanger is likely the pre-cooler, as there is only about a 40°C temperature change but it operates close to the CO{sub 2} critical point, therefore inducing substantial changes in properties. The proposed research will focus on this most challenging component. The third task examines seal leakage through various dynamic seal designs under the conditions expected in the S-CO{sub 2} cycle

  6. Heat exchanger analysis on a Microvax II/GPX

    Science.gov (United States)

    Haught, Alan F.

    1988-12-01

    The finite element code FIDAP was used to examine the fluid flow path within a flat plate tube/fin heat exchanger and the resulting heat transfer from the fins and tube walls. The mathematical formulation, mesh development and analysis procedure are presented, and the results obtained are compared with experimental observations of the fluid flow and measurements of the fluid heating. This problem illustrates the capabilities of finite element techniques for analyzing complex three-dimensional convection-dominated heat transfer, and demonstrates the scope of problems which can be addressed on a Micro VAX II/GPX workstation.

  7. Diffusion Welding of Compact Heat Exchangers for Nuclear Applications

    Energy Technology Data Exchange (ETDEWEB)

    Denis Clark; Ron Mizia; Dr. Michael V. Glazoff; Mr. Michael W. Patterson

    2012-06-01

    The next-­-generation nuclear plant (NGNP) is designed to be a flexible source of energy, producing various mixes of electrical energy and process heat (for example, for hydrogen generation) on demand. Compact heat exchangers provide an attractive way to move energy from the helium primary reactor coolant to process heat uses. For process heat efficiency, reactor outlet temperatures of 750-­-900°C are desirable. There are minor but deleterious components in the primary coolant; the number of alloys that can handle this environment is small. The present work concentrates on Alloys 800H and 617.

  8. Dynamic tube/support interaction in heat exchanger tubes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.S.

    1991-01-01

    The supports for heat exchanger tubes are usually plates with drilled holes; other types of supports also have been used. To facilitate manufacture and to allow for thermal expansion of the tubes, small clearances are used between tubes and tube supports. The dynamics of tube/support interaction in heat exchangers is fairly complicated. Understanding tube dynamics and its effects is important for heat exchangers. This paper summarizes the current state of the art on this subject and to identify future research needs. Specifically, the following topics are discussed: dynamics of loosely supported tubes, tube/support gap dynamics, tube response in flow, tube damage and wear, design considerations, and future research needs. 55 refs., 1 fig.

  9. Compact heat exchanger for power plants; Kompakti siirrin tyoentyy myoes kotimaan voimalaitoksiin

    Energy Technology Data Exchange (ETDEWEB)

    Kinnunen, L. [Energia-lehti, Helsinki (Finland)

    2001-07-01

    Vahterus Oy, located at Kalanti, has manufactured heat exchangers since the beginning of 1990s. About 90% of the equipment produced are exported. In the PSHE (Plate and Shell) solution of the Vahterus heat exchanger the heat is transferred by round plated welded to form a compact package, which is assembled into a cylindrical steel casing. The heat exchanger contains no gaskets or soldered joints, which eliminates the leak risks. Traditional heat exchanges are usually operated at higher temperatures and pressures, but the heat transfer capacities of them are lower. Plate heat exchangers, on the other hand, are efficient, but the application range of them is narrow. Additionally, the rubber gasket of the heat exchange plates, sealing the joints of the heat exchanging plates, does not stand high pressures or temperatures, or corroding fluids. The new welded plate heat exchanger combine the pressure and temperature resistance of tube heat exchangers and the high heat exchange capacity of plate heat exchangers. The new corrosion resisting heat exchanger can be applied for especially hard conditions. The operating temperature range of the PSHE heat exchanger is - 200 - 900 deg C. The pressure resistance is as high as 100 bar. The space requirement of PSHE is only one tenth of the space requirement of traditional tube heat exchangers. Adjusting the number of heat exchanging plates can change the capacity of the heat exchanger. Power range of the heat exchanger can be as high as 80 MW. Due to the corrosion preventive construction and the small dimension the PSHE heat exchanger can be applied for refrigerators using ammonia as refrigerant. These kinds of new Vahterus heat exchangers are in use in 60 countries in more than 2000 refrigerators.

  10. Simulation on Thermal Integrity of the Fin/Tube Brazed Joint of Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    Yiyu QIAN; Feng GAO; Fengjiang WANG; Hui ZHAO

    2003-01-01

    In the applications of heat exchangers, the fin efficiency of heat transfer is the key issue. Thermal distribution withinthe brazed joints in heat exchanger under loading conditions is investigated in this paper. Simulated results showedthat the therma

  11. Performance of a Thermoelectric Device with Integrated Heat Exchangers

    Science.gov (United States)

    Barry, Matthew M.; Agbim, Kenechi A.; Chyu, Minking K.

    2015-06-01

    Thermoelectric devices (TEDs) convert heat directly into electrical energy, making them well suited for waste heat recovery applications. An integrated thermoelectric device (iTED) is a restructured TED that allows more heat to enter the p-n junctions, thus producing a greater power output . An iTED has heat exchangers incorporated into the hot-side interconnectors with flow channels directing the working fluid through the heat exchangers. The iTED was constructed of p- and n-type bismuth-telluride semiconductors and copper interconnectors and rectangular heat exchangers. The performance of the iTED in terms of , produced voltage and current , heat input and conversion efficiency for various flow rates (), inlet temperatures (C) ) and load resistances () with a constant cold-side temperature ( = 0C) was conducted experimentally. An increase in had a greater effect on the performance than did an increase in . A 3-fold increase in resulted in a 3.2-, 3.1-, 9.7-, 3.5- and 2.8-fold increase in and respectively. For a constant of 50C, a 3-fold increase in from 3300 to 9920 resulted in 1.6-, 1.6-, 2.6-, 1.5- and 1.9-fold increases in , , , and respectively.

  12. The influence of a radiated heat exchanger surface on heat transfer

    Directory of Open Access Journals (Sweden)

    Morel Sławomir

    2015-09-01

    Full Text Available The experiment leads to establish the influence of radiated surface development heat exchangers on the values of heat flux transferred with water flowing through the exchangers and placed in electric furnace chamber. The values of emissivity coefficients are given for the investigated metal and ceramic coatings. Analytical calculations have been made for the effect of the heating medium (flame – uncoated wall and then heating medium (flame – coated wall reciprocal emissivity coefficients. Analysis of the values of exchanged heat flux were also realized. Based on the measurement results for the base coating properties, these most suitable for spraying the walls of furnaces and heat exchangers were selected, and determined by the intensification of heat exchange effect. These coatings were used to spray the walls of a laboratory waste-heat boiler, and then measurements of fluxes of heat absorbed by the cooling water flowing through the boiler tubes covered with different type coatings were made. Laboratory tests and calculations were also confirmed by the results of full-scale operation on the metallurgical equipment.

  13. The influence of a radiated heat exchanger surface on heat transfer

    Science.gov (United States)

    Morel, Sławomir

    2015-09-01

    The experiment leads to establish the influence of radiated surface development heat exchangers on the values of heat flux transferred with water flowing through the exchangers and placed in electric furnace chamber. The values of emissivity coefficients are given for the investigated metal and ceramic coatings. Analytical calculations have been made for the effect of the heating medium (flame) - uncoated wall and then heating medium (flame) - coated wall reciprocal emissivity coefficients. Analysis of the values of exchanged heat flux were also realized. Based on the measurement results for the base coating properties, these most suitable for spraying the walls of furnaces and heat exchangers were selected, and determined by the intensification of heat exchange effect. These coatings were used to spray the walls of a laboratory waste-heat boiler, and then measurements of fluxes of heat absorbed by the cooling water flowing through the boiler tubes covered with different type coatings were made. Laboratory tests and calculations were also confirmed by the results of full-scale operation on the metallurgical equipment.

  14. Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate

    Energy Technology Data Exchange (ETDEWEB)

    Mittereder, N.; Poerschke, A.

    2013-11-01

    This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHP in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season. Upon completion of the monitoring phase, measurements revealed that the initial TRNSYS simulated horizontal sub-slab ground loop heat exchanger fluid temperatures and heat transfer rates differed from the measured values. To determine the cause of this discrepancy, an updated model was developed utilizing a new TRNSYS subroutine for simulating sub-slab heat exchangers. Measurements of fluid temperature, soil temperature, and heat transfer were used to validate the updated model.

  15. Characterization of a mini-channel heat exchanger for a heat pump system

    Science.gov (United States)

    Arteconi, A.; Giuliani, G.; Tartuferi, M.; Polonara, F.

    2014-04-01

    In this paper a mini-channel aluminum heat exchanger used in a reversible heat pump is presented. Mini-channel finned heat exchangers are getting more and more interest for refrigeration systems, especially when compactness and low refrigerant charge are desired. Purpose of this paper was to characterize the mini-channel heat exchanger used as evaporator in terms of heat transfer performance and to study the refrigerant distribution in the manifold. The heat exchanger characterization was performed experimentally by means of a test rig built up for this purpose. It is composed of an air-to-air heat pump, air channels for the external and internal air circulation arranged in a closed loop, measurement sensors and an acquisition system. The overall heat transfer capacity was assessed. Moreover, in order to characterize the flow field of the refrigerant in the manifold of the heat exchanger, a numerical investigation of the fluid flow by means of CFD was performed. It was meant to evaluate the goodness of the present design and to identify possible solutions for the future improvement of the manifold design.

  16. Numerical Modeling of Fin and Tube Heat Exchanger for Waste Heat Recovery

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

    In the present work, multiphysics numerical modeling is carried out to predict the performance of a liquid-gas fin and tube heat exchanger design. Three-dimensional (3D) steady-state numerical model using commercial software COMSOL based on finite element method (FEM) is developed. The study...... associates conjugate heat transfer phenomenon with the turbulent flow to describe the variable temperature and velocity profile. The performance of heat exchanger design is investigated in terms of overall heat transfer coefficient, Nusselt number, Colburn j-factor, flow resistance factor, and efficiency...... between fin and tube. The present numerical model predicts the performance of the heat exchanger design, therefore, can be applied to existing waste heat recovery systems to improve the overall performance with optimized design and process-dependent parameters....

  17. Effect of Corrugation Angle on Heat Transfer Studies of Viscous Fluids in Corrugated Plate Heat Exchangers

    Directory of Open Access Journals (Sweden)

    B Sreedhara Rao

    2015-04-01

    Full Text Available In the present investigation heat transfer studies are conducted in corrugated plate heat exchangers (PHEs having three different corrugation angles of 300, 400 and 500. The plate heat exchangers have a length of 30 cm and a width of 10 cm with a spacing of 5 mm. Water and 20% glycerol solution are taken as test fluids and hot fluid is considered as heating medium. The wall temperatures are measured along the length of exchanger at seven different locations by means of thermocouples. The inlet and outlet temperatures of test fluid and hot fluid are measured by means of four more thermocouples. The experiments are conducted at a flowrate ranging from 0.5 lpm to 6 lpm with the test fluid. Film heat transfer coefficient and Nusselt number are determined from the experimental data. These values are compared with different corrugation angles. The effects of corrugation angles on heat transfer rates are discussed.

  18. Optimization of the Heat Exchangers of a Thermoelectric Generation System

    Science.gov (United States)

    Martínez, A.; Vián, J. G.; Astrain, D.; Rodríguez, A.; Berrio, I.

    2010-09-01

    The thermal resistances of the heat exchangers have a strong influence on the electric power produced by a thermoelectric generator. In this work, the heat exchangers of a thermoelectric generator have been optimized in order to maximize the electric power generated. This thermoelectric generator harnesses heat from the exhaust gas of a domestic gas boiler. Statistical design of experiments was used to assess the influence of five factors on both the electric power generated and the pressure drop in the chimney: height of the generator, number of modules per meter of generator height, length of the fins of the hot-side heat exchanger (HSHE), length of the gap between fins of the HSHE, and base thickness of the HSHE. The electric power has been calculated using a computational model, whereas Fluent computational fluid dynamics (CFD) has been used to obtain the thermal resistances of the heat exchangers and the pressure drop. Finally, the thermoelectric generator has been optimized, taking into account the restrictions on the pressure drop.

  19. HEAT EXCHANGE NETWORKS IN BIODIESEL PRODUCTION FROM WASTE COOKING OILS

    Directory of Open Access Journals (Sweden)

    María Fernanda Laborde

    2014-11-01

    Full Text Available With the objective to aboard one of the challenges in Engineering teaching: It´s the application in professional practice?, along with attending to the actual requirements of achieve energetic efficiency in industrial process and to reuse wastes of food industry, this work, presents the application of heat exchange networks for the resolution of a real case: pre-treatment of waste cooking oils (WCO withacid catalysis for biodiesel production. Different methods and software are applied to obtain the minimum amounts of heat and the heat exchange network for a processing capacity of 0,19 kg/s of WCO. A minimum temperature difference (Tmin of 10°C is considered and the minimum requirements of heating and cooling result 4629,87 W and 10066,30 W, respectively. If this exchange network is not considered, this values increase to 26838,33 W and 21958,33 W, respectively. Applying heat exchange network, decrease 78,92% the required steam service in the process and water cooling service decreases 62,48%, demonstrating that integration reduces energetic requirements respect the non-integrated process.

  20. Comparisons of Heat Transfer Performance of a Closed-looped Oscillating Heat Pipe and Closed-looped Oscillating Heat Pipe with Check Valves Heat Exchangers

    Directory of Open Access Journals (Sweden)

    P. Meena

    2008-01-01

    Full Text Available This research was to study the comparisons of heat transfer performance of closed-looped oscillating heat pipe and closed-looped oscillating heat pipe with check valves heat exchangers with R134a, Ethanol and water were used as the working fluids. A set of heat pipe heat exchanger (CLOHP and CLOHP/CV were made of copper tubes in combination of following dimension: 2.03 mm inside diameter: 40 turns, with 20, 10 and 20 cm for evaporator, adiabatic and condenser sections lengths. The working fluid was filled in the tube at the filling ratio of 50%. The evaporator section was given heat by heater while the condenser section was cooled by air. The adiabatic section was properly insulated. In the test operation, it could be concluded as follows. It indicated that the heat transfer performance of closed-looped oscillating heat pipe with check valves heat exchanger better than closed-looped oscillating heat exchanger.

  1. Spacecraft Radiator Freeze Protection Using a Regenerative Heat Exchanger

    Science.gov (United States)

    Ungar, Eugene K.; Schunk, Richard G.

    2011-01-01

    An active thermal control system architecture has been modified to include a regenerative heat exchanger (regenerator) inboard of the radiator. Rather than using a radiator bypass valve a regenerative heat exchanger is placed inboard of the radiators. A regenerator cold side bypass valve is used to set the return temperature. During operation, the regenerator bypass flow is varied, mixing cold radiator return fluid and warm regenerator outlet fluid to maintain the system setpoint. At the lowest heat load for stable operation, the bypass flow is closed off, sending all of the flow through the regenerator. This lowers the radiator inlet temperature well below the system set-point while maintaining full flow through the radiators. By using a regenerator bypass flow control to maintain system setpoint, the required minimum heat load to avoid radiator freezing can be reduced by more than half compared to a radiator bypass system.

  2. Thermal Analysis of Fin and Tube Heat Exchanger

    OpenAIRE

    2014-01-01

    This paper studied experimentally the effect of heat transfer of fin and tube type heat exchanger for different mass flow rate of fluid. The thermal stresses induced on fin and tube is also studied by ansys software at steady state condition by changing the width of fin and diameter of tube. Readings were taken experimentally by changing mass flow rate of fluid at respective temperatures. Comparison was done on theoretically and experimentally obtained results. It is observed ...

  3. Numerical Simulation of Different Models of Heat Pipe Heat Exchanger Using AcuSolve

    Directory of Open Access Journals (Sweden)

    Zainal Nurul Amira

    2017-01-01

    Full Text Available In this paper, a numerical simulation of heat pipe heat exchanger (HPHE is computed by using CFD solver program i.e. AcuSolve. Two idealized model of HPHE are created with different variant of entry’s dimension set to be case 1 and case 2. The geometry of HPHE is designed in SolidWorks and imported to AcuSolve to simulate the fluid flow numerically. The design of HPHE is the key to provide a heat exchanger system to work proficient as expected. Finally, the result is used to optimize and improving heat recovery systems of the increasing demand for energy efficiency in industry.

  4. Heat transfer characteristics of a new helically coiled crimped spiral finned tube heat exchanger

    Science.gov (United States)

    Srisawad, Kwanchanok; Wongwises, Somchai

    2009-02-01

    In the present study, the heat transfer characteristics in dry surface conditions of a new type of heat exchanger, namely a helically coiled finned tube heat exchanger, is experimentally investigated. The test section, which is a helically coiled fined tube heat exchanger, consists of a shell and a helical coil unit. The helical coil unit consists of four concentric helically coiled tubes of different diameters. Each tube is constructed by bending straight copper tube into a helical coil. Aluminium crimped spiral fins with thickness of 0.5 mm and outer diameter of 28.25 mm are placed around the tube. The edge of fin at the inner diameter is corrugated. Ambient air is used as a working fluid in the shell side while hot water is used for the tube-side. The test runs are done at air mass flow rates ranging between 0.04 and 0.13 kg/s. The water mass flow rates are between 0.2 and 0.4 kg/s. The water temperatures are between 40 and 50°C. The effects of the inlet conditions of both working fluids flowing through the heat exchanger on the heat transfer coefficients are discussed. The air-side heat transfer coefficient presented in term of the Colburn J factor is proportional to inlet-water temperature and water mass flow rate. The heat exchanger effectiveness tends to increase with increasing water mass flow rate and also slightly increases with increasing inlet water temperature.

  5. Investigation of Condensing Ice Heat Exchangers for MTSA Technology Development

    Science.gov (United States)

    Padilla, Sebastian; Powers, Aaron; Ball, Tyler; Lacomini, Christie; Paul, Heather L.

    2009-01-01

    Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed for thermal, carbon dioxide (CO2) and humidity control for a Portable Life Support Subsystem (PLSS). Metabolically-produced CO2 present in the ventilation gas of a PLSS is collected using a CO2-selective adsorbent via temperature swing adsorption. The temperature swing is initiated through cooling to well below metabolic temperatures. Cooling is achieved with a sublimation heat exchanger using water or liquid carbon dioxide (L CO2) expanded below sublimation temperature when exposed to low pressure or vacuum. Subsequent super heated vapor, as well as additional coolant, is used to further cool the astronaut. The temperature swing on the adsorbent is then completed by warming the adsorbent with a separate condensing ice heat exchanger (CIHX) using metabolic heat from moist ventilation gas. The condensed humidity in the ventilation gas is recycled at the habitat. The water condensation from the ventilation gas represents a significant source of potential energy for the warming of the adsorbent bed as it represents as much as half of the energy potential in the moist ventilation gas. Designing a heat exchanger to efficiently transfer this energy to the adsorbent bed and allow the collection of the water is a challenge since the CIHX will operate in a temperature range from 210K to 280K. The ventilation gas moisture will first freeze and then thaw, sometimes existing in three phases simultaneously.

  6. Development of a Program for Predicting Flow Instability in a Once-through Sodium- Heated Steam Generator

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eui Kwang; Kim, Dehee; Kim, Jong Bum; Lee, Tae-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    A SG selected for PGSFR is of a once-through integrated type. It is a vertical counter flow shell and tube heat exchanger with sodium on the shell side and water-steam in the tubes. The phenomenon of two-phase flow instability has been observed in many industrial domains such as boiling systems and steam generators. In this paper, a computer program developed for predicting two-phase flow instability in a steam generator under axial non-uniform heat flux is presented, and analysis results for verification are presented. A computer code was developed for investigating the two-phase flow stability under sodium-heated conditions in the shell-side of a SG. A solution algorithm for the sodium flow field and tube conduction has been developed for application to sodium-heated SG.

  7. Compact/micro heat exchangers – Their role in heat pumping equipment

    OpenAIRE

    Kew, PA; Reay, DA; 2nd Micro and Nano Flows Conference (MNF2009)

    2009-01-01

    This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications. Compact and micro-heat exchangers have many advantages over their larger ...

  8. A novel compact heat exchanger using gap flow mechanism

    Science.gov (United States)

    Liang, J. S.; Zhang, Y.; Wang, D. Z.; Luo, T. P.; Ren, T. Q.

    2015-02-01

    A novel, compact gap-flow heat exchanger (GFHE) using heat-transfer fluid (HTF) was developed in this paper. The detail design of the GFHE coaxial structure which forms the annular gap passage for HTF is presented. Computational fluid dynamics simulations were introduced into the design to determine the impacts of the gap width and the HTF flow rate on the GFHE performance. A comparative study on the GFHE heating rate, with the gap widths ranged from 0.1 to 1.0 mm and the HTF flow rates ranged from 100 to 500 ml/min, was carried out. Results show that a narrower gap passage and a higher HTF flow rate can yield a higher average heating rate in GFHE. However, considering the compromise between the GFHE heating rate and the HTF pressure drop along the gap, a 0.4 mm gap width is preferred. A testing loop was also set up to experimentally evaluate the GFHE capability. The testing results show that, by using 0.4 mm gap width and 500 ml/min HTF flow rate, the maximum heating rate in the working chamber of the as-made GFHE can reach 18 °C/min, and the average temperature change rates in the heating and cooling processes of the thermal cycle test were recorded as 6.5 and 5.4 °C/min, respectively. These temperature change rates can well satisfy the standard of IEC 60068-2-14:2009 and show that the GFHE developed in this work has sufficient heat exchange capacity and can be used as an ideal compact heat exchanger in small volume desktop thermal fatigue test apparatus.

  9. Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate

    Energy Technology Data Exchange (ETDEWEB)

    Mittereder, Nick [IBACOS, Inc., Pittsburgh, PA (United States); Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

    2013-11-01

    This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHP in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season.

  10. Teaching Heat Exchanger Network Synthesis Using Interactive Microcomputer Graphics.

    Science.gov (United States)

    Dixon, Anthony G.

    1987-01-01

    Describes the Heat Exchanger Network Synthesis (HENS) program used at Worcester Polytechnic Institute (Massachusetts) as an aid to teaching the energy integration step in process design. Focuses on the benefits of the computer graphics used in the program to increase the speed of generating and changing networks. (TW)

  11. Fouling characteristics of compact heat exchangers and enhanced tubes.

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, C. B.; Rabas, T. J.

    1999-07-15

    Fouling is a complex phenomenon that (1) encompasses formation and transportation of precursors, and (2) attachment and possible removal of foulants. A basic understanding of fouling mechanisms should guide the development of effective mitigation techniques. The literature on fouling in complex flow passages of compact heat exchangers is limited; however, significant progress has been made with enhanced tubes.

  12. Catalytic heat exchangers - a long-term evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Silversand, Fredrik A. [CATATOR AB, Lund (Sweden)

    2003-10-01

    A long-term evaluation concerning catalytic heat exchangers (CHEs) has been performed. The idea concerning CHEs was originally described in a number of reports issued by Catator almost a decade ago. The general idea with CHEs is to combust a fuel with a catalyst inside a heat exchanger to enable an effective heat transfer. The first design approaches demonstrated the function and the possibilities with CHEs but were defective concerning the heat exchanger design. Consequently, a heat exchanger company (SWEP International AB), which was specialised on brazed plate-type heat exchangers, joined the continued development project. Indeed, the new design approach containing Catator's wire-mesh catalysts and SWEP's plate-type heat exchangers enabled us to improve the concept considerably. The new design complied with a number of relevant technical demands, e.g.: Simplicity; Compactness and integration (few parts); High thermal efficiency; Low pressure drop; Excellent emissions; High turn-down ratio; Reasonable production cost. Spurred by the technical progresses, the importance of a long-term test under realistic conditions was clear. A long-term evaluation was initialised at Sydkraft Gas premises in Aastorp. The CHE was installed on a specially designed rig to enable accelerated testing with respect to the number of transients. The rig was operated continuously for 5000 hours and emission mapping was carried out at certain time intervals. Following some problems during the initial phase of the long-term evaluation, which unfortunately also delayed the project, the results indicated very stable conditions of operation. The emissions have been rather constant during the course of the test and we cannot see any tendencies to decreased performances. Indeed, the test verifies the function, operability and reliability of the CHE-concept. Apart from domestic boilers we foresee a number of interesting and relevant applications in heating and process technology. Since

  13. Novel Power Electronics Three-Dimensional Heat Exchanger: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, K.; Cousineau, J.; Lustbader, J.; Narumanchi, S.

    2014-08-01

    Electric drive systems for vehicle propulsion enable technologies critical to meeting challenges for energy, environmental, and economic security. Enabling cost-effective electric drive systems requires reductions in inverter power semiconductor area. As critical components of the electric drive system are made smaller, heat removal becomes an increasing challenge. In this paper, we demonstrate an integrated approach to the design of thermal management systems for power semiconductors that matches the passive thermal resistance of the packaging with the active convective cooling performance of the heat exchanger. The heat exchanger concept builds on existing semiconductor thermal management improvements described in literature and patents, which include improved bonded interface materials, direct cooling of the semiconductor packages, and double-sided cooling. The key difference in the described concept is the achievement of high heat transfer performance with less aggressive cooling techniques by optimizing the passive and active heat transfer paths. An extruded aluminum design was selected because of its lower tooling cost, higher performance, and scalability in comparison to cast aluminum. Results demonstrated a heat flux improvement of a factor of two, and a package heat density improvement over 30%, which achieved the thermal performance targets.

  14. Dual Expander Cycle Rocket Engine with an Intermediate, Closed-cycle Heat Exchanger

    Science.gov (United States)

    Greene, William D. (Inventor)

    2008-01-01

    A dual expander cycle (DEC) rocket engine with an intermediate closed-cycle heat exchanger is provided. A conventional DEC rocket engine has a closed-cycle heat exchanger thermally coupled thereto. The heat exchanger utilizes heat extracted from the engine's fuel circuit to drive the engine's oxidizer turbomachinery.

  15. The computational optimization of heat exchange efficiency in stack chimneys

    Energy Technology Data Exchange (ETDEWEB)

    Van Goch, T.A.J.

    2012-02-15

    For many industrial processes, the chimney is the final step before hot fumes, with high thermal energy content, are discharged into the atmosphere. Tapping into this energy and utilizing it for heating or cooling applications, could improve sustainability, efficiency and/or reduce operational costs. Alternatively, an unused chimney, like the monumental chimney at the Eindhoven University of Technology, could serve as an 'energy channeler' once more; it can enhance free cooling by exploiting the stack effect. This study aims to identify design parameters that influence annual heat exchange in such stack chimney applications and optimize these parameters for specific scenarios to maximize the performance. Performance is defined by annual heat exchange, system efficiency and costs. The energy required for the water pump as compared to the energy exchanged, defines the system efficiency, which is expressed in an efficiency coefficient (EC). This study is an example of applying building performance simulation (BPS) tools for decision support in the early phase of the design process. In this study, BPS tools are used to provide design guidance, performance evaluation and optimization. A general method for optimization of simulation models will be studied, and applied in two case studies with different applications (heating/cooling), namely; (1) CERES case: 'Eindhoven University of Technology monumental stack chimney equipped with a heat exchanger, rejects heat to load the cold source of the aquifer system on the campus of the university and/or provides free cooling to the CERES building'; and (2) Industrial case: 'Heat exchanger in an industrial stack chimney, which recoups heat for use in e.g. absorption cooling'. The main research question, addressing the concerns of both cases, is expressed as follows: 'what is the optimal set of design parameters so heat exchange in stack chimneys is optimized annually for the cases in which a

  16. Entropy generation extremum and entransy dissipation extremum for heat exchanger optimization

    Institute of Scientific and Technical Information of China (English)

    LIU XiongBin; MENG JiAn; GUO ZengYuan

    2009-01-01

    The applicability of the extremum principles of entropy generation and entransy dissipation is studied for heat exchanger optimization. The extremum principle of entransy dissipation gives better optimization results when heat exchanger is only for the purpose of heating and cooling, while the extremum principle of entropy generation is better for the heat exchanger optimization when it works in the Brayton cycle. The two optimization principles are approximately equivalent when the temperature drops of the streams in a heat exchanger are small.

  17. Studi Eksperimen Analisa Performa Compact Heat Exchanger Louvered Fin Flat Tube untuk pemanfaatan Waste Energy

    Directory of Open Access Journals (Sweden)

    Taqwim Ismail

    2014-03-01

    Full Text Available Waste Heat Recovery merupakan instalasi yang digunakan untuk memanfaatkan kembali waste energy seperti exhaust gas. Penelitian dilakukan pada compact heat exchanger tipe louvered fin flat tube sebagai salah satu komponen penyusun waste heat recovery system. Eksperimen dilakukan dengan mendesain compact heat exchanger tipe louvered fin flat tube kemudian dilakukan pengujian pada compact heat exchanger yang telah didesain. Pengujian dilakukan dengan memberikan tiga variasi kecepatan putaran fan sisi exhaust gas, yaitu 0.2, 0.3, dan 0.4 m/s untuk mengetahui unjuk kerja yang berbeda dari compact heat exchanger yang telah didesain.  Hasil yang didapatkan dari studi eksperimen ini adalah dimensi dari compact heat exchanger tipe louvered fin flat tube dan beberapa parameter yang menunjukkan unjuk kerja dari compact heat exchanger seperti nilai heat transfer baik dari sisi air maupun sisi exhaust gas, effectiveness, number of transfer unit (NTU, overall heat transfer coefficient, dan  ΔTLMTD dari compact heat exchanger.

  18. VHTR engineering design study: intermediate heat exchanger program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-11-01

    The work reported is the result of a follow-on program to earlier Very High Temperature Reactor (VHTR) studies. The primary use of the VHTR is to provide heat for various industrial processes, such as hydrocarbon reforming and coal gasification. For many processes the use of an intermediate heat transfer barrier between the reactor coolant and the process is desirable; for some processes it is mandatory. Various intermediate heat exchanger (IHX) concepts for the VHTR were investigated with respect to safety, cost, and engineering design considerations. The reference processes chosen were steam-hydrocarbon reforming, with emphasis on the chemical heat pipe, and steam gasification of coal. The study investigates the critically important area of heat transfer between the reactor coolant, helium, and the various chemical processes.

  19. Modeling heat efficiency, flow and scale-up in the corotating disc scraped surface heat exchanger

    DEFF Research Database (Denmark)

    Friis, Alan; Szabo, Peter; Karlson, Torben

    2002-01-01

    A comparison of two different scale corotating disc scraped surface heat exchangers (CDHE) was performed experimentally. The findings were compared to predictions from a finite element model. We find that the model predicts well the flow pattern of the two CDHE's investigated. The heat transfer...

  20. Heat exchanger modeling and identification for control of waste heat recovery systems in diesel engines

    NARCIS (Netherlands)

    Feru, E.; Willems, F.P.T.; Rojer, C.; Jager, B. de; Steinbuch, M.

    2013-01-01

    To meet future CO2 emission targets, Waste Heat Recovery systems have recently attracted much attention for automotive applications, especially for long haul trucks. This paper focuses on the development of a dynamic counter-flow heat exchanger model for control purposes. The model captures the dyna

  1. A Numerical Study of a Double Pipe Latent Heat Thermal Energy Storage System

    Science.gov (United States)

    Tabassum, Tonny

    Solar energy is an intermittent supply source of energy. To efficiently utilize this free renewable energy source some form of thermal energy storage devices are necessary. Phase change materials (PCMs), because of their high energy density storage capacity and near isothermal phase change characteristics, have proven to be promising candidates for latent heat thermal energy storage (LHTES) devices. Among the various LHTES devices for low temperature residential heating and cooling applications, the shell-and-tube type heat exchanging devices are the most simple to operate and can be easily fabricated. This work numerically investigates the buoyancy driven heat transfer process during melting (charging) of a commercial paraffin wax as PCM filling the annulus of a horizontal double pipe heat exchanger. The heated working fluid (water) is passing through the central tube of the annulus at a sufficiently high flow-rate and thereby maintaining an almost isothermal wall temperature at the inner pipe which is higher than the melting temperature of the PCM. The transient, two-dimensional coupled laminar momentum and energy equations for the model are suitably non-dimensionalized and are solved numerically using the enthalpy-porosity approach. Time-wise evolutions of the flow patterns and temperature distributions are presented through velocity vector fields and isotherm plots. In this study, two types of PCM filled annuli, a plain annulus and a strategically placed longitudinal finned annulus, are studied. The total energy stored, the total liquid fraction and the energy efficiency at different melting times are evaluated for three different operating conditions and the results are compared between the plain and finned annuli. The present study will provide guidelines for system thermal performance and design optimization of the shell-and-tube LHTES devices. .

  2. HEAT TRANSFER COEFFICIENT AND FRICTION FACTOR CHARACTERISTICS OF A GRAVITY ASSISTED BAFFLED SHELL AND HEAT-PIPE HEAT EXCHANGER

    Directory of Open Access Journals (Sweden)

    P. Raveendiran

    2015-06-01

    Full Text Available The heat transfer coefficients and friction factors of a baffled shell and heat pipe heat exchanger with various inclination angles were determined experimentally; using methanol as working fluid and water as heat transport fluid were reported. Heat pipe heat exchanger reported in this investigation have inclination angles varied between 15o and 60o for different mass flow rates and temperature at the shell side of the heat exchanger. All the required parameters like outlet temperature of both hot and cold side of heat exchanger and mass flow rate of fluids were measured using an appropriate instrument. Different tests were performed from which condenser side heat transfer coefficient and friction factor were calculated. In all operating conditions it has been found that the heat transfer coefficient increases by increasing the mass flow rate and angle of inclination. The reduction in friction factor occurs when the Reynolds number is increased. The overall optimum experimental effectiveness of GABSHPHE has found to be 42% in all operating conditioning at ψ = 45o.

  3. Active heat exchange system development for latent heat thermal energy storage

    Science.gov (United States)

    Lefrois, R. T.; Mathur, A. K.

    1980-01-01

    Five tasks to select, design, fabricate, test and evaluate candidate active heat exchanger modules for future applications to solar and conventional utility power plants were discussed. Alternative mechanizations of active heat exchange concepts were analyzed for use with heat of fusion phase change materials (PCMs) in the temperature range of 250 to 350 C. Twenty-six heat exchange concepts were reviewed, and eight were selected for detailed assessment. Two candidates were selected for small-scale experimentation: a coated tube and shell heat exchanger and a direct contact reflux boiler. A dilute eutectic mixture of sodium nitrate and sodium hydroxide was selected as the PCM from over 50 candidate inorganic salt mixtures. Based on a salt screening process, eight major component salts were selected initially for further evaluation. The most attractive major components in the temperature range of 250 to 350 C appeared to be NaNO3, NaNO2, and NaOH. Sketches of the two active heat exchange concepts selected for test are given.

  4. Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, Paul A.; Thole, Karen A. [Virginia Tech, Blacksburg, VA (United States). Mechanical Engineering Department

    2006-10-15

    The louvered fin heat exchanger, a type of compact heat exchanger, has been used heavily in the automotive and air conditioning industries for the last several decades. The majority of past research, aimed towards improving louvered fin exchanger efficiency, has focused on optimizing various parameters of the louvered fin. The experimental study presented in this paper concentrates instead on augmenting the heat transfer along the tube wall of the compact heat exchanger through the use of winglets placed on the louvers. The experiments were completed on a 20 times scaled model of an idealized louvered fin exchanger with a fin pitch to louver pitch ratio of 0.76 and a louver angle of 27{sup o}. The Reynolds numbers tested, based on louver pitch, were between 230 and 1016. A number of geometrical winglet parameters, including angle of attack, aspect ratio, direction, and shape, were all evaluated based on heat transfer augmentation, friction factor augmentation, and efficiency index (combination of both augmentations). In an attempt to optimize these winglet parameters, tube wall heat transfer augmentations as high as 39% were achieved with associated friction factor augmentations as high as 23%. (author)

  5. Active heat exchange system development for latent heat thermal energy storage

    Science.gov (United States)

    Lefrois, R. T.; Mathur, A. K.

    1980-04-01

    Five tasks to select, design, fabricate, test and evaluate candidate active heat exchanger modules for future applications to solar and conventional utility power plants were discussed. Alternative mechanizations of active heat exchange concepts were analyzed for use with heat of fusion phase change materials (PCMs) in the temperature range of 250 to 350 C. Twenty-six heat exchange concepts were reviewed, and eight were selected for detailed assessment. Two candidates were selected for small-scale experimentation: a coated tube and shell heat exchanger and a direct contact reflux boiler. A dilute eutectic mixture of sodium nitrate and sodium hydroxide was selected as the PCM from over 50 candidate inorganic salt mixtures. Based on a salt screening process, eight major component salts were selected initially for further evaluation. The most attractive major components in the temperature range of 250 to 350 C appeared to be NaNO3, NaNO2, and NaOH. Sketches of the two active heat exchange concepts selected for test are given.

  6. Thermoacoustics with idealized heat exchangers and no stack.

    Science.gov (United States)

    Wakeland, Ray Scott; Keolian, Robert M

    2002-06-01

    A model is developed for thermoacoustic devices that have neither stack nor regenerator. These "no-stack" devices have heat exchangers placed close together in an acoustic standing wave of sufficient amplitude to allow individual parcels of gas to enter both exchangers. The assumption of perfect heat transfer in the exchangers facilitates the construction of a simple model similar to the "moving parcel picture" that is used as a first approach to stack-based engines and refrigerators. The model no-stack cycle is shown to have potentially greater inviscid efficiency than a comparable stack model. However, losses from flow through the heat exchangers and on the walls of the enclosure are greater than those in a stack-based device due to the increased acoustic pressure amplitude. Estimates of these losses in refrigerators are used to compare the possible efficiencies of real refrigerators made with or without a stack. The model predicts that no-stack refrigerators can exceed stack-based refrigerators in efficiency, but only for particular enclosure geometries.

  7. A one-dimensional heat transfer model for parallel-plate thermoacoustic heat exchangers.

    Science.gov (United States)

    de Jong, J A; Wijnant, Y H; de Boer, A

    2014-03-01

    A one-dimensional (1D) laminar oscillating flow heat transfer model is derived and applied to parallel-plate thermoacoustic heat exchangers. The model can be used to estimate the heat transfer from the solid wall to the acoustic medium, which is required for the heat input/output of thermoacoustic systems. The model is implementable in existing (quasi-)1D thermoacoustic codes, such as DeltaEC. Examples of generated results show good agreement with literature results. The model allows for arbitrary wave phasing; however, it is shown that the wave phasing does not significantly influence the heat transfer.

  8. Numerical Simulation of Heat Transfer in a Gas Solid Crossflow Moving Packed Bed Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    Anyuan Liu; Shi Liu; Yufeng Duan; Zhonggang Pan

    2001-01-01

    The mechanism of heat transfer in a crossfiow moving packed bed heat transfer exchanger is analyzed and a two dimensional heat transfer mathematical model has been developed based on the two fluid model (TFM) approach, in which both phases are considered to be continuous and fully interpenetrating. This model is solved by means of numerical method and the results are approximately in agreement with the experimental ones.

  9. Experimental Investigation of Ice Phase Change Material Heat Exchangers

    Science.gov (United States)

    Leimkuehler, Thomas O.; Stephan, Ryan A.

    2012-01-01

    Phase change materials (PCM) may be useful for spacecraft thermal control systems that involve cyclical heat loads or cyclical thermal environments. Thermal energy can be stored in the PCM during peak heat loads or in adverse thermal environments. The stored thermal energy can then be released later during minimum heat loads or in more favorable thermal environments. This can result in a decreased turndown ratio for the radiator and a reduced system mass. The use of water as a PCM rather than the more traditional paraffin wax has the potential for significant mass reduction since the latent heat of formation of water is approximately 70% greater than that of wax. One of the potential drawbacks of using ice as a PCM is its potential to rupture its container as water expands upon freezing. In order to develop a space qualified ice PCM heat exchanger, failure mechanisms must first be understood. Therefore, a methodical experimental investigation has been undertaken to demonstrate and document specific failure mechanisms due to ice expansion in the PCM. A number of ice PCM heat exchangers were fabricated and tested. Additionally, methods for controlling void location in order to reduce the risk of damage due to ice expansion were investigated. This paper presents an overview of the results of this investigation from the past three years.

  10. Subscale Water Based Phase Change Material Heat Exchanger Development

    Science.gov (United States)

    Sheth, Rubik; Hansen, Scott

    2016-01-01

    Supplemental heat rejection devices are required in many spacecraft as the radiators are not sized to meet the full heat rejection demand. One means of obtaining additional heat rejection is through the use of phase change material heat exchangers (PCM HX's). PCM HX's utilize phase change to store energy in unfavorable thermal environments (melting) and reject the energy in favorable environments (freezing). Traditionally, wax has been used as a PCM on spacecraft. However, water is an attractive alternative because it is capable of storing about 40% more energy per unit mass due to its higher latent heat of fusion. The significant problem in using water as a PCM is its expansion while freezing, leading to structural integrity concerns when housed in an enclosed heat exchanger volume. Significant investigation and development has taken place over the past five years to understand and overcome the problems associated with water PCM HX's. This paper reports on the final efforts by Johnson Space Center's Thermal Systems Branch to develop a water based PCM HX. The test article developed and reported on is a subscale version of the full-scale water-based PCM HX's constructed by Mezzo Technologies. The subscale unit was designed by applying prior research on freeze front propagation and previous full-scale water PCM HX development. Design modifications to the subscale unit included use of urethane bladder, decreased aspect ratio, perforated protection sheet, and use of additional mid-plates. Testing of the subscale unit was successful and 150 cycles were completed without fail.

  11. Airside performances of finned eight-tube heat exchangers

    Science.gov (United States)

    Li, Cheng; Li, Junming

    2016-11-01

    For applications in the relatively low temperature refrigeration systems with large constant temperature bath, the present work performed the experimental studies on the airside performances of the staggered finned eight-tube heat exchangers with large fin pitches. The airside heat transfer coefficients and pressure drops for three fin types and two fin pitches are obtained and analyzed. The heat transfer enhancement with louver fins is 11-16 % higher than the flat fins and that with sinusoidal corrugated fins is 1.1-3.4 % higher than the flat fins. Higher Re brings larger enhancement for various fins. Fin pitches show weak influence on heat transfer for eight tube rows. However, effects of fin pitch on heat transfer for both the sinusoidal corrugation and the louvered fin are larger than the flat fins and they are different from those for N ≤ 6. Airside Colburn j factor are compared with previous and it could be concluded that the airside j factor is almost constant for finned tube heat exchangers with eight tubes and large fin pitches, when Re is from 250 to 2500. The results are different from previous studies for fewer tube rows.

  12. RESEARCH OF SHORT DIFFUSERS IMPLEMENTATION EFFICIENCY IN COMPACT HEAT EXCHANGERS

    Directory of Open Access Journals (Sweden)

    Yusha V.L

    2014-12-01

    Full Text Available Increasing of efficiency of air condenser with the help of cooling air distribution is considered. The relevance of research connected with preservation of the compact sizes of the heat exchange device is presented. The analysis of shortcomings of the existing designs on the basis of the tubular heat exchanger with the short diffuser is carried out. Various devices and recommendations about improvement of operation of the short diffuser are considered. The research objective consisting in an assessment of influence of a configuration of flowing part of the short diffuser on overall performance of the heat exchange device is formulated. The methodology of carrying out the engineering analysis of cooling equipment on the base of ANSYS CFX is developed. The calculation of tubular cooler characteristics with several alternatives of the inlet section is made, the analysis of results from the point of view of losses of pressure in the diffuser and amounts of the taken-away heat is carried out. The improvement in cooler work using guide rails for its inlet section is discovered.

  13. Simulation of embedded heat exchangers of solar aided ground source heat pump system

    Institute of Scientific and Technical Information of China (English)

    王芳; 郑茂余; 邵俊鹏; 李忠建

    2008-01-01

    Aimed at unbalance of soil temperature field of ground source heat pump system, solar aided energy storage system was established. In solar assisted ground-source heat pump (SAGSHP) system with soil storage, solar energy collected in three seasons was stored in the soil by vertical U type soil exchangers. The heat abstracted by the ground-source heat pump and collected by the solar collector was employed to heating. Some of the soil heat exchangers were used to store solar energy in the soil so as to be used in next winter after this heating period; and the others were used to extract cooling energy directly in the soil by circulation pump for air conditioning in summer. After that solar energy began to be stored in the soil and ended before heating period. Three dimensional dynamic numerical simulations were built for soil and soil heat exchanger through finite element method. Simulation was done in different strata month by month. Variation and restoration of soil temperature were studied. Economy and reliability of long term SAGSHP system were revealed. It can be seen that soil temperature is about 3 ℃ higher than the original one after one year’s running. It is beneficial for the system to operate for long period.

  14. Fabrication of Wire Mesh Heat Exchangers for Waste Heat Recovery Using Wire-Arc Spraying

    Science.gov (United States)

    Rezaey, R.; Salavati, S.; Pershin, L.; Coyle, T.; Chandra, S.; Mostaghimi, J.

    2014-04-01

    Waste heat can be recovered from hot combustion gases using water-cooled heat exchangers. Adding fins to the external surfaces of the water pipes inserted into the hot gases increases their surface area and enhances heat transfer, increasing the efficiency of heat recovery. A method of increasing the heat transfer surface area has been developed using a twin wire-arc thermal spray system to generate a dense, high-strength coating that bonds wire mesh to the outside surfaces of stainless steel pipes through which water passes. At the optimum spray distance of 150 mm, the oxide content, coating porosity, and the adhesion strength of the coating were measured to be 7%, 2%, and 24 MPa, respectively. Experiments were done in which heat exchangers were placed inside a high-temperature oven with temperature varying from 300 to 900 °C. Several different heat exchanger designs were tested to estimate the total heat transfer in each case. The efficiency of heat transfer was found to depend strongly on the quality of the bond between the wire meshes and pipes and the size of openings in the wire mesh.

  15. Heat transfer and pressure drop characteristics of nanofluids in a plate heat exchanger.

    Science.gov (United States)

    Kwon, Y H; Kim, D; Li, C G; Lee, J K; Hong, D S; Lee, J G; Lee, S H; Cho, Y H; Kim, S H

    2011-07-01

    In this paper, the heat transfer characteristics and pressure drop of the ZnO and Al2O3 nanofluids in a plate heat exchanger were studied. The experimental conditions were 100-500 Reynolds number and the respective volumetric flow rates. The working temperature of the heat exchanger was within 20-40 degrees C. The measured thermophysical properties, such as thermal conductivity and kinematic viscosity, were applied to the calculation of the convective heat transfer coefficient of the plate heat exchanger employing the ZnO and Al2O3 nanofluids made through a two-step method. According to the Reynolds number, the overall heat transfer coefficient for 6 vol% Al2O3 increased to 30% because at the given viscosity and density of the nanofluids, they did not have the same flow rates. At a given volumetric flow rate, however, the performance did not improve. After the nanofluids were placed in the plate heat exchanger, the experimental results pertaining to nanofluid efficiency seemed inauspicious.

  16. Experimental investigation on heat transfer and pressure drop of conical coil heat exchanger

    Directory of Open Access Journals (Sweden)

    Purandare Pramod S.

    2016-01-01

    Full Text Available The heat transfer and pressure drop analysis of conical coil heat exchanger with various tube diameters, fluid flow rates, and cone angles is presented in this paper. Fifteen coils of cone angles 180° (horizontal spiral, 135°, 90°, 45°, and 0° (vertical helical are fabricated and analysed with, same average coil diameter, and tube length, with three different tube diameters. The experimentation is carried out with hot and cold water of flow rate 10 to 100 L per hour (Reynolds range 500 to 5000, and 30 to 90 L per hour, respectively. The temperatures and pressure drop across the heat exchanger are recorded at different mass flow rates of cold and hot fluid. The various parameters: heat transfer coefficient, Nusselt number, effectiveness, and friction factor, are estimated using the temperature, mass flow rate, and pressure drop across the heat exchanger. The analysis indicates that, Nusselt number and friction factor are function of flow rate, tube diameter, cone angle, and curvature ratio. Increase in tube side flow rate increases Nusselt number, whereas it reduces with increase in shell side flow rate. Increase in cone angle and tube diameter, reduces Nusselt number. The effects of cone angle, tube diameter, and fluid flow rates on heat transfer and pressure drop characteristics are detailed in this paper. The empirical correlations are proposed to bring out the physics of the thermal aspects of the conical coil heat exchangers.

  17. Two-Phase Flow Instability in Water-side Tube of SG under Axially Uniform Heat Flux Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eui Kwang; Kim, Dehee; Jung, Yoon; Lee, Tae-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The SG of PGSFR is of once through integrated type, and is a vertical counter flow shell and tube heat exchanger with sodium on shell side and water-steam in tubes. The phenomenon of two-phase flow instability has been observed in many industrial domains like boiling systems, steam generators. In this paper the numerical methods were studied, and a computer code was developed for two-phase flow instability in steam generator, and representative results of the model calculations are presented. A computer code is developed for investigating two-phase flow stability under constant heat flux conditions. Solution algorithm for the sodium flow field and tube conduction will be developed for the application to sodium-heated SG.

  18. Laboratory simulation of heat exchange for liquids with Pr > 1: Heat transfer

    Science.gov (United States)

    Belyaev, I. A.; Zakharova, O. D.; Krasnoshchekova, T. E.; Sviridov, V. G.; Sukomel, L. A.

    2016-02-01

    Liquid metals are promising heat transfer agents in new-generation nuclear power plants, such as fast-neutron reactors and hybrid tokamaks—fusion neutron sources (FNSs). We have been investigating hydrodynamics and heat exchange of liquid metals for many years, trying to reproduce the conditions close to those in fast reactors and fusion neutron sources. In the latter case, the liquid metal flow takes place in a strong magnetic field and strong thermal loads resulting in development of thermogravitational convection in the flow. In this case, quite dangerous regimes of magnetohydrodynamic (MHD) heat exchange not known earlier may occur that, in combination with other long-known regimes, for example, the growth of hydraulic drag in a strong magnetic field, make the possibility of creating a reliable FNS cooling system with a liquid metal heat carrier problematic. There exists a reasonable alternative to liquid metals in FNS, molten salts, namely, the melt of lithium and beryllium fluorides (Flibe) and the melt of fluorides of alkali metals (Flinak). Molten salts, however, are poorly studied media, and their application requires detailed scientific substantiation. We analyze the modern state of the art of studies in this field. Our contribution is to answer the following question: whether above-mentioned extremely dangerous regimes of MHD heat exchange detected in liquid metals can exist in molten salts. Experiments and numerical simulation were performed in order to answer this question. The experimental test facility represents a water circuit, since water (or water with additions for increasing its electrical conduction) is a convenient medium for laboratory simulation of salt heat exchange in FNS conditions. Local heat transfer coefficients along the heated tube, three-dimensional (along the length and in the cross section, including the viscous sublayer) fields of averaged temperature and temperature pulsations are studied. The probe method for measurements in

  19. Simulated annealing technique to design minimum cost exchanger

    Directory of Open Access Journals (Sweden)

    Khalfe Nadeem M.

    2011-01-01

    Full Text Available Owing to the wide utilization of heat exchangers in industrial processes, their cost minimization is an important target for both designers and users. Traditional design approaches are based on iterative procedures which gradually change the design and geometric parameters to satisfy a given heat duty and constraints. Although well proven, this kind of approach is time consuming and may not lead to cost effective design as no cost criteria are explicitly accounted for. The present study explores the use of nontraditional optimization technique: called simulated annealing (SA, for design optimization of shell and tube heat exchangers from economic point of view. The optimization procedure involves the selection of the major geometric parameters such as tube diameters, tube length, baffle spacing, number of tube passes, tube layout, type of head, baffle cut etc and minimization of total annual cost is considered as design target. The presented simulated annealing technique is simple in concept, few in parameters and easy for implementations. Furthermore, the SA algorithm explores the good quality solutions quickly, giving the designer more degrees of freedom in the final choice with respect to traditional methods. The methodology takes into account the geometric and operational constraints typically recommended by design codes. Three different case studies are presented to demonstrate the effectiveness and accuracy of proposed algorithm. The SA approach is able to reduce the total cost of heat exchanger as compare to cost obtained by previously reported GA approach.

  20. Non-newtonian heat transfer on a plate heat exchanger with generalized configurations

    Energy Technology Data Exchange (ETDEWEB)

    Carezzato, A.; Tadini, C.C.; Gut, J.A.W. [Department of Chemical Engineering, Escola Politecnica, University of Sao Paulo, Sao Paulo (Brazil); Alcantara, M.R. [Department of Fundamental Chemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo (Brazil); Telis-Romero, J. [Department of Food Engineering and Technology, Universidade Estadual Paulista, Sao Jose do Rio Preto (Brazil)

    2007-01-15

    For the configuration optimization of plate heat exchangers (PHEs), the mathematical models for heat transfer and pressure drop must be valid for a wide range of operational conditions of all configurations of the exchanger or the design results may be compromised. In this investigation, the thermal model of a PHE is adjusted to fit experimental data obtained from non-Newtonian heat transfer for eight different configurations, using carboxymethylcellulose solutions (CMC) as test fluid. Although it is possible to successfully adjust the model parameters, Newtonian and non-Newtonian heat transfer cannot be represented by a single generalized correlation. In addition, the specific heat, thermal conductivity and power-law rheological parameters of CMC solutions were correlated with temperature, over a range compatible with a continuous pasteurization process. (Abstract Copyright [2007], Wiley Periodicals, Inc.)