ANALISA JURNAL PERPINDAHAN PANAS “Analisa Perpindahan Panas Pada Plat Bergelombang Penukar Panas dari Geometry Plat yang Berbeda: A Review”

TUGAS

ANALISA JURNAL PERPINDAHAN PANAS

“Analisa Perpindahan Panas Pada Plat Bergelombang Penukar Panas dari

Geometry Plat yang Berbeda: A Review”

 

Disusun oleh :

                    Sutarto                       K2513065

Dosen Pembimbing :

Danar Susilo W., ST., M.Eng.

Tugas ini disusun untuk memenuhi tugas mata kuliah

Perpindahan Panas

Pendidikan Teknik Mesin

Jurusan Pendidikan Teknik dan Kejuruan

Fakultas Kegururan dan Ilmu Pendidikan

Universitas Sebelas Maret

Surakarta

International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com [ISSN 2250-2459, Volume 2, Issue 10, Oct 2012]

Heat Transfer Analysis of Corrugated Plate Heat Exchanger of

Different Plate Geometry: A Review

Jogi Nikhil G.¹, Assist. Prof. Lawankar Shailendra M.²

¹ M.Tech student, ² Assistant Professor, Government College of Engineering, Amravati. Maharashtra, India

Abstract— Corrugated plate heat exchangers have larger heat transfer surface area and increased turbulence level due to the corrugations. In this study, experimental heat transfer data will obtained for single phase flow (water-to-water) configurations in a corrugated plate heat exchanger for symmetric 45°/45°, 45°/75° chevron angle plates. The effect of variation of chevron angles with other geometric parameter on the heat transfer coefficient will be study. Reynold number ranging from 500 to 2500 and Prandtl number ranging from 3.5 to 6.5 will be taken for given experiment.Based on the experimental data, a correlation will estimate for Nusselt number as a function of Reynolds number, Prandtl number and chevron angle.

Keywords—Chevron angle, Corrugated plate heat exchangers, Heat transfer coefficient, Nusselt number, Prandtl number, Reynolds number, Single phase flow.

I.  INTRODUCTION

Plate Heat Exchangers have a number of applications in the pharmaceutical, petrochemical, chemical, power, dairy, food & beverage industry. Recently, plate heat exchangers are commonly used when compared to other types of heat exchangers such as shell and tube type in heat transfer processes because of their compactness, ease of production, sensitivity, easy care after set-up and efficiency.The temperature approach in a plate heat exchangers may be as low as 1 °C whereas shell and tube heat exchangers require an approach of 5 °C or more.

A.  Plate Heat Exchanger

As shown in Figure 1, the plate heat exchanger is basically a series of individual plates pressed between two heavy end covers. These plates are gasketed, welded or brazed together depending on the application of the heat exchanger. The basic geometry of plates used in plate heat exchanger is shown in figure2.Stainless steel is a commonly used metal for the plates because of its ability to withstand high temperatures, its strength, and its corrosion resistance.

The entire assembly is held together by the tie bolts. Individual plates are hung from the top carrying bar and are guided by the bottom carrying bar. For single-pass circuiting, hot and cold side fluid connections are usually located on the fixed end cover. Multi-pass circuiting results in fluid connections on both fixed and moveable end covers. The plates are pressed to form troughs at right angles to the direction of flow of the liquid which runs through the channels in the heat exchanger. These troughs are arranged so that they interlink with the other plates which forms the channel with gaps of 1.3–1.5 mm between the plates.

Figure 1.Various parts of plate heat exchanger

Material required for plate heat exchanger parts : Plate material - 316 stainless steel

Gasket material - Nitriale Butadiene Rubber (NBR) Nozzle material - 316 stainless steel

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com [ISSN 2250-2459, Volume 2, Issue 10, Oct 2012]

Figure 2. Basic geometry of chevron plate [15]

B.  Fluid Flow in Plate Heat Exchanger

Figure 2, illustrates the nature of fluid flow through the plate heat exchanger. The primary and secondary fluids flow in opposite directions on either side of the plates. Water flow and circuiting are controlled by the placement of the plate gaskets. By varying the position of the gasket, water can be channelled over a plate or past it. Gaskets are installed in such a way that a gasket failure cannot result in a mixing of the fluids. In addition, the outer circumference of all gaskets is exposed to the atmosphere. As a result, should a leak occur, a visual indication is provided.

Figure 3. Fluid flow in plate heat exchanger

C.  Geometric Parameter Affecting Plate Heat Exchanger

Chevron Angle, β: Typically varying from 20° to 65°, β is the measure of softness (small β, low thermal efficiency and pressure drop) and hardness (large β, high thermal efficiency and pressure drop) of thermal and hydraulic characteristics of plates. Some authors define ‗‗Π/2- β‖ as the chevron angle.

Surface Enlargement Factor, φ: φ is the ratio of developed area [based on corrugation pitch, P_c,and plate pitch, p] to the projected area(viz. L_w×L_p , L_w = L_h+ D_p and L_p = L_v – D_p)

Corrugation Depth or Mean Channel Spacing, b: b = p–t, the difference between plate pitch, p and the plate thickness, t

Channel Flow Area, A_x: A_x is the minimum flow area between plates and is estimated as product of plate corrugation depth and width of plate (i.e., A_x = b × L_w)

Channel Hydraulic Diameter, D_h: D_h is defined as four times ratio of minimum flow area to wetted perimeter, D_h = 2bL_w/(b+L_w φ) .Since b<<L_w, D_h is usually taken to be 2b/φ.

D.  Physical  Parameters Affecting  Plate Heat Exchanger

The six most important parameters are as follows:

•     The amount of heat to be transferred (heat load).

•     The inlet and outlet temperatures on the primary and secondary sides.

•     The maximum allowable pressure drop on the primary and secondary sides.

•     The maximum operating temperature.

•     The maximum operating pressure.

•     The flow rate on the primary and secondary sides.

Temperature Program: This means the inlet and outlet temperatures of both media in the heat exchanger.

Heat Load: Disregarding heat losses to the atmosphere, which are negligible, the heat lost (heat load) by one side of a plate heat exchanger is equal to the heat gained by the other. The heat load (P) is expressed in kW or kcal/h.

Logarithmic Mean Temperature Difference: Logarithmic mean temperature difference (LMTD) is the effective driving force in the heat exchanger.

Thermal Length: Thermal length (θ) is the relationship between temperature difference dt on one side and LMTD.

q = ^dt LMTD

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International Journal of Emerging Technology and Advanced Engineering

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Thermal length describes how difficult a duty is from a thermal perspective.

Density: Density (ρ) is the mass per unit volume and is expressed in kg/m³ or kg/dm³.

Flow Rate: This can be expressed in two different terms, either by weight or by volume. The units of flow by weight are in kg/s or kg/h, the units of flow by volume in m³/h or l/min. To convert units of volume into units of weight, it is necessary to multiply the volume flow by the density.

Pressure Drop: Pressure drop (Δp) is in direct relationship to the size of the plate heat exchanger. If it is possible to increase the allowable pressure drop, and incidentally accept higher pumping costs, then the heat exchanger will be smaller and less expensive. As a guide, allowable pressure drops between 20 and 100 kPa are accepted as normal for water/water duties.

Specific Heat: Specific heat (c_p) is the amount of energy required to raise 1 kg of a substance by one degree centigrade. The specific heat of water at 20°C is 4.182 kJ/kg °C or 1.0 kcal/kg °C.

Viscosity: Viscosity is a measure of the ease of flow of a liquid. The lower the viscosity, the more easily it flows. Viscosity is expressed in centipoises (cP) or centistokes (cSt).

Overall Heat Transfer Coefficient: Overall heat transfer coefficient (U) is a measure of the resistance to heat flow, made up of the resistances caused by the plate material, amount of fouling, nature of the fluids and type of exchanger used. Overall heat transfer coefficient is expressed as W/m² °C or kcal/h, m² °C.

Thermal Length [θ]:

q = ^dt LMTD

Logarithmic Mean Temperature Difference [LMTD]:

_{LMTD =} ^DT1 ^{- DT}2 ln(DT₁ / DT₂ )

Here, DT₁  = T₁  - T₄ , DT₂  = T₂  - T₃

Where, T₁ = Temperature inlet – hot side T₂ = Temperature outlet – hot side T₃ = Temperature inlet – cold side T₄ = Temperature outlet – cold side

Total Overall Heat Transfer Coefficient [U]:

1	=	1	+	1	+	Dx	+ Rf
U		hhs		hcs		k

Where,

h_hs=The heat transfer coefficient between the hot medium and the heat transfer surface [W/m² °C]

h_cs = The heat transfer coefficient between the heat transfer surface and the cold medium[W/m² °C]

Δx = The thickness of the heat transfer surface [m] R_f = The fouling factor [m² °C/W]

k = The thermal conductivity of the material separating the medias [W/m °C]

Heat Transfer Correlation: The heat transfer correlation for a fluid flow past a solid surface is expressed in a dimensionless form is given as:

Nu = Nu(Re, Pr) Where,

E. Heat Transfer Analysis Heat Load, P:

p = mc _p dt and

P = h ´ A ´ LMTD

Where,

P = heat load [kW]

m = mass flow rate [kg/s] c_p = specific heat [kJ/kg °C]

dt = temperature difference between inlet and outlet on one side [°C]

h = heat transfer coefficient [W/m² °C] A = heat transfer area [m²]

LMTD = log mean temperature difference

Nu= Nusselt number Re=Reynolds number Pr =Prandtl number

For fully developed laminar flows, we expected the Nusselt number Nu to be constant however for a turbulent flow it is expressed as:

Nu = C₁ Re^a Pr^b

Where,C₁, α & β are constants.

II.  LATERATURE SURVEY

Focke W. W. et al. [1] established that the inclination angle between plate corrugations and the overall flow direction is a major parameter in the thermo hydraulic performance of plate heat exchangers.

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The observed maximum transfer rate at an angle of about 80° is explained from the observed flow patterns. At higher angles the flow pattern becomes less effective for transfer, in particular at 90° marked flow separation is observed.

Mehrabian M. A. and Pouter R. [2] studies the local hydrodynamic and thermal characteristics of the flow between two identical APV SR3 plates and looks at the effect of corrugation angle on the performance when the plate spacing is fixed. The CFD calculations show that the inclination angle between the plate corrugations and the overall flow direction is a major parameter in the thermo hydraulic performance of plate heat exchangers.

Metwally H. M. and Mbanglik R. M. [3] considered Laminar periodically developed forced convection in sinusoidal corrugated-plate channels with uniform wall temperature and single-phase constant property flows. The flow field is found to be strongly influenced by γ and Re, and it displays two distinct regimes: a low Re or γ undisturbed laminar-flow regime and a high Re or γ swirl-flow regime.

Gradeck M. et al. [4] performed experiments to study effects of hydrodynamic conditions on the enhancement of heat transfer for single phase flow. These experiments have been conducted for a wide range of Reynolds numbers, [0 < Re < 7500] in order to obtain the different regimes from steady laminar to turbulent. Finally they have pointed out a strong relation between the wall velocity gradient and the Nusselt number. Further investigations will be made on two-phase and boiling flow.

Bobbili Prabhakara Rao et al. [5] carried out experimental investigation to find the flow and the pressure difference across the port to channel in plate heat exchangers for a wide range of Reynolds number 1000– 17000. In their study, low corrugation angle plates have been used for different number of channels, namely, 20 and 80. Water has been used as working fluid for both hot and cold fluids.

Longo and Gasparella [6] carried out experiments using water as a working fluid in herringbone type plate heat exchanger with chevron angle of 65˚ and developed Nusselt number correlation. They used modified Wilson plot technique and incorporated variable fluid property effects.

Garcı´a Cascales J. R. et al. [7] focused on the study of heat transfer in plate heat exchangers working with R-22 and R-290, comparing different correlations for the evaluation of the heat transfer coefficient.

Naphon Paisarn [8] presented the effect of relevant parameters on the heat transfer characteristics and pressure drop.

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The corrugated plates of different corrugated tile angles 20°, 40° and 60° with the height of the channel of 12.5 mm for the heat flux and the Reynolds number in the ranges of 0.5–1.2 kW/m² and 500–1400 are tested. Due to the presence of recirculation zones, the corrugated surface has significant effect on the enhancement of heat transfer and pressure drop.

Using the Buckingham Pi theorem, Lin J.H. et al. [9] derives dimensionless correlations to characterize the heat transfer performance of the corrugated channel in a plate heat exchanger. The experimental data are substituted into these correlations to identify the flow characteristics and channel geometry parameters with the most significant influence on the heat transfer performance.

Zhi-jian Luan et al. [10] designed a new-type corrugation plate heat exchanger and carried out experimental and numerical simulations for observing heat transfer performance and effect of flow resistance of the working fluid on it.

Warnakulasuriya and Worek [11] investigated heat transfer and pressure drop of a viscous absorbent salt solution in a commercial plate heat exchanger. Overall heat transfer coefficient and Nusselt number are reported to increase with Reynolds number while friction factor decreased. Based on the experimental data, correlations for Nusselt number and friction factor were proposed.

Tsai Ying-Chi et al.[12] investigated the hydrodynamic characteristics and distribution of flow in two cross-corrugated channels of plate heat exchangers. The velocity, pressure and flow distribution of the fluid among the two channels of the plate heat exchanger with its local flow characteristics around the contact points have been proposed.

Dovic´ D. et al. [13] investigated characteristics of the flow in chevron plate heat exchangers through visualization tests of channels with β = 28˚and β = 61˚.Mathematical model is then developed with the aim of deriving correlations for prediction of f and Nu for flow in channels of arbitrary geometry [β and b/l]

Durmus Aydın et al. [14] studied the effects of surface geometries of three different type heat exchangers called as PHEflat [Flat plate heat exchanger], PHE corrugated [Corrugated plate heat exchanger] and PHE asteriks [Asterisk plate heat exchanger] on heat transfer, friction factor and exergy loss. The experiments were carried out for laminar flow conditions with single pass in parallel and counter flow direction having Reynolds number and Prandtl number in the range of 50 ≤ Re ≤ 1000 and 3 ≤ Pr ≤ 7, respectively.

International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com [ISSN 2250-2459, Volume 2, Issue 10, Oct 2012]

Khan T. S. et al. [15] carried out experiment for single phase flow [water-to-water] configurations in a commercial plate heat exchanger for symmetric 30˚/30˚, 60˚/60˚, and mixed 30˚/60˚ chevron angle plates having Reynold number ranging from 500 to 2500 and Prandtl number from 3.5 to 6.5. Based on the experimental data, a correlation to estimate Nusselt number as a function of Reynolds number, Prandtl number and chevron angle has been proposed.

Gherasim Iulian et al. [16] presented an experimental investigation of the hydrodynamic and thermal fields in a two channel chevron-type plate heat exchanger for laminar and turbulent conditions. The friction factor for a Reynolds number up to 850 and the Nusselt number for the hot channel for a Reynolds number up to 1500 are presented.

Dh	Channel hydraulic diameter [m]
ρ	Density [kgm-3  or kgdm-3]
Δp	Pressure drop [kPa]

γ                aspect ratios

SUBSCRIPT

h         Hydraulic

hs        Hot Surface

cs        Cold Surface

REFERENCES

[1]     Focke W.W, Zachariades J., Olivier I. , 1985 ―The effect of the corrugation inclination angle on the thermo hydraulic performance of plate heat exchangers‖, Int. J. Heat Mass Transfer 28 [8], pp

1469–1479.

III.  CONCLUSION

Experiments have been performed to investigate heat transfer characteristics of a commercial plate heat exchanger with different chevron angles and other geometrical parameters under turbulent flow conditions. Reynolds number is varied from about 500–2500.Based on the experimental data, a simplified Nusselt number correlation incorporating effects of Reynolds number, Prandtl number, viscosity variation and chevron angle trying to be propose.

IV.  FUTURE SCOPE

Different types of plates will also be tested and investigated using the set-up constructed. Based on the experimental results obtained from the set-up and the computational fluid dynamics analysis of the same cases, new correlations can be found for the different plate geometries to be tested and analyzed.

With the result of new experiments, the selection program can also be extended for new type of plate geometries.

NOMENCLATURE

D_p     Port diameter [m]

β       Chevron angle [⁰C]

L_w     Plate width [m]

L_h      Horizontal distance between centers of ports [m]

P_c      Corrugation pitch [m]

t        Plate thickness [m]

L_v      Vertical distance between centers of ports [m]

L_h      Horizontal distance between centers of ports [m]

b       Corrugation depth or mean channel spacing [m]

φ               Surface enlargement factor

A_x     Channel flow area [m²]

[2]     Mehrabian M.A , Poulter R., 2000 ―Hydrodynamics and thermal characteristics of corrugated channels: computational approach‖,

Applied Mathematical Modelling 24 ,pp 343-364

[3]     Metwally H.M. , Manglik R.M. ,2004 ―Enhanced heat transfer due to curvature-induce lateral vortices in laminar flows in sinusoidal corrugated-plate channels‖, International Journal of Heat and Mass

Transfer 47, pp 2283–2292

[4]     Gradeck M. , Hoareau B., Lebouche M.,2005 ―Local analysis of heat transfer inside corrugated channel‖, International Journal of Heat and Mass Transfer 48 ,pp1909–1915

[5]     Bobbili Prabhakara Rao , Sunden Bengt , Das Sarit K.,2006 ―An experimental investigation of the port flow maldistribution in small and large plate package heat exchangers‖, Applied Thermal

Engineering 26 ,pp 1919–1926

[6]     Longo G.A., Gasparella A., 2007 ―Refrigerant R134a vaporization heat transfer and pressure drop inside a small brazed plate heat exchanger‖, International Journal of Refrigeration 30 , pp 821–830.

[7]     Garcı´a-Cascales J.R., Vera-Garcı´a F., Corber‘an-Salvador J.M., Gonz‘alvez- Maci‘a J. , 2007 ― Assessment of boiling and condensation heat transfer correlations in the modelling of plate heat exchangers‖, International Journal of Refrigeration 30 ,pp 1029-10.

[8]     Naphon  Paisarn,  2007  ―  Laminar  convective  heat  transfer  and

pressure drop   in   the     corrugated   channels‖,   International

Communications in Heat and Mass Transfer 34,pp 62–71

[9]     Lin J.H. , Huang C.Y., Su C.C., 2007 ―Dimensional analysis for the heat transfer characteristics in the corrugated channels of plate heat exchangers‖, International Communications in Heat and Mass Transfer 34 ,pp 304–312

[10]  Zhi-jian LUAN, Guan-min ZHANG, Mao-cheng TIAN, Ming-xiu

FAN ,2008 ―Flow resistance and heat transfer characteristics of a new-type plate heat exchanger‖, Journal of Hydrodynamics 20 ,pp 524-529

[11]  Warnakulasuriya F.S.K, Worek W.M.,2008, ―Heat transfer and pressure drop properties of high viscous solutions in plate heat exchangers‖, International Journal of Heat and Mass Transfer 51 ,pp

52–67.

[12]  Tsai Ying-Chi, Liu Fung-Bao , Shen Po-Tsun, 2009 ―Investigations of the pressure drop and flow distribution in a chevron-type plate heat exchanger, International Communications in Heat and Mass Transfer 36 ,pp 574–578

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Website: www.ijetae.com [ISSN 2250-2459, Volume 2, Issue 10, Oct 2012]

[13]  Dovic´ D. , Palm B. , Švaic´ S. ,2009 ―Generalized correlations for predicting heat transfer and pressure drop in plate heat exchanger channels of arbitrary geometry‖, International Journal of Heat and

Mass Transfer 52 ,pp 4553–4563

[14]  Durmus Aydın , Benli Huseyin , Kurtbas Irfan , Gul Hasan , 2009 ―Investigation of heat transfer and pressure drop in plate heat exchangers having different surface profiles‖, International Journal of Heat and Mass Transfer 52,pp 1451–1457

[15]  Khan T.S. , Khan M.S. , Chyu Ming-C. , Ayub Z.H. ,2010― Experimental investigation of single phase convective heat transfer coefficient in a corrugated plate heat exchanger for multiple plate configurations‖, Applied Thermal Engineering 30 ,pp1058–1065

[16]    Gherasim Iulian, Taws Matthew , Galanis a Nicolas , Nguyen Cong Tam,2011―Heat transfer and fluid flow in a plate heat exchanger part

I. Experimental investigation‖,    International Journal of Thermal

Sciences 50,pp 1492-1498

Jurnal Internasional Emerging Technology dan Advanced Engineering

Website: www.ijetae.com [ISSN 2250-2459, Volume 2, Issue 10, Oct 2012]

Analisa Perpindahan Panas Pada Plat Bergelombang Penukar Panas dari

Geometry Plat yang Berbeda: A Review

Jogi Nikhil G.¹, Assist. Prof. Lawankar Shailendra M.²

¹ M.Tech student, ² Assistant Professor, Government College of Engineering, Amravati. Maharashtra, India

Abstract - Pelat gelombang penukar panas memiliki area permukaan perpindahan panas yang lebih luas dan dapat meningkatkan tingkat turbulensi karena adanya lipatan. Dalam penelitian ini,  percobaan data perpindahan panas diperoleh untuk aliran satu fasa (air-to-air) konfigurasi dalam pelat penukar panas bergelombang simetris pada plat dengan sudut chevron 45 ° / 45 °, 45 ° / 75 ° . Pengaruh variasi sudut chevron dengan parameter geometris lainnya pada koefisien perpindahan panas akan dipelajari. Bilangan Reynold mulai 500-2500 dan bilangan Prandtl mulai dari 3,5-6,5 akan diambil untuk percobaan. Dasar data dari percobaan, korelasi akan digunakan untuk memperkirakan bilangan Nusselt sebagai fungsi dari bilangan Reynolds, nomor Prandtl dan sudut chevron.

Kata kunci –sudut Chevron, plat bergelombang penukar panas, koefisien perpindahan panas, Bilangan Nusselt, Bilangan Prandtl, bilangan Reynolds, aliran fase tunggal.

                                                           I.PENDAHULUAN
Plat penukar panas memiliki sejumlah aplikasi dalam industri farmasi, petrokimia, kimia, listrik, susu, makanan & minuman. Baru-baru ini, pelat penukar panas biasanya banyak digunakan karena bila dibandingkan dengan jenis lain dari penukar panas seperti shell dan tube tipe dalam proses perpindahan panas karena kekompakan mereka, kemudahan produksi, sensitivitas, perawatan yang mudah setelah set-up dan pendekatan suhu efficiency. Temperatur di sebuah pelat penukar panas dapat serendah 1 ° C sedangkan penukar panas  shell dan tube memerlukan pendekatan 5 ° C atau lebih.

                                     .
A. Plat Heat Exchanger                                  .
       Seperti ditunjukkan dalam Gambar 1, pelat (Heat Exchanger) penukar panas pada dasarnya adalah serangkaian plat tunggal yang ditekan di antara dua heavy end cover. Plat ini gasketed, dilas atau dibrazing bersama-sama tergantung pada aplikasi heat exchanger. Geometri dasar pelat yang digunakan dalam pelat heat exchanger ditunjukkan pada gambar 2. Stainless steel adalah logam yang biasa digunakan untuk pelat karena kemampuannya untuk menahan suhu tinggi, kuat, dan tahanan korosi.                                .
        Seluruh perakitan dilakukan bersama dengan baut. Plat tunggal digantung dari atas batang dan disangga oleh bagian bawah dimana ada batang. Untuk arus single-pass, koneksi fluida sisi panas dan dingin biasanya terletak pada fixed dan cove. Arus Multi-pass hasil pada sambungan cairan pada kedua end cover. Pelat yang ditekan untuk membentuk palung di sudut kanan ke arah aliran cairan yang mengalir melalui saluran dalam penukar panas. Palung ini diatur sedemikian rupa sehingga mereka dihubungkan dengan plat lain yang membentuk saluran dengan celah dari 1,3-1,5 mm antara pelat.

GAMBAR 1

                                    GAMBAR 2

B. Aliran Fluida di Plat Heat Exchanger                                 .
Gambar 2, menggambarkan sifat aliran fluida melalui pelat Heat Exchanger. Cairan primer dan sekunder mengalir dalam arah yang berlawanan di kedua sisi plat. Aliran air dan arus dikendalikan oleh penempatan gasket plat. Dengan memvariasikan posisi gasket, air dapat disalurkan melalui plat atau melewatinya. Gasket dipasang sedemikian rupa bahwa kegagalan gasket tidak dapat menghasilkan pencampuran cairan. Selain itu, lingkar luar semua gasket terkena atmosfer. Akibatnya, harus kebocoran terjadi, indikasi visual disediakan.

C. Parameter Geometric yang Mempengaruhi Plat Heat Exchanger                  .
Sudut Chevron, β: Biasanya bervariasi dari 20 ° sampai 65 °, β adalah ukuran soft (β kecil, efisiensi termal yang rendah dan penurunan tekanan) dan kekerasan (β besar, efisiensi termal yang tinggi dan penurunan tekanan) dari karakteristik termal dan hidraulik plat. Beberapa penulis mendefinisikan ‗‗Π / 2- β‖ sebagai sudut chevron.

Faktor Pembesaran Permukaan, φ: φ adalah rasio daerah dikembangkan [berdasarkan tingkatan kerut, Pc, dan tingkatan plat, p] ke daerah yang diproyeksikan (yaitu. L_w×L_p , L_w = L_h+ D_p and L_p = L_v – D_p)

Kedalaman Kerut atau Berarti Saluran Spacing, b: b = p-t, perbedaan antara tingkatan lempeng, p dan ketebalan plat, t Daerah Aliran Channel, Ax: Ax adalah daerah aliran minimum antara plat dan diperkirakan sebagai produk pelat kerut kedalaman dan lebar plat (yaitu, Ax = b × Lw) Saluran hidrolik Diameter, Dh: Dh didefinisikan sebagai empat kali rasio daerah aliran minimum untuk perimeter dibasahi,                        .,
Dh = 2bLw / (b + Lw φ) .Sejak b << Lw, Dh biasanya diambil untuk
menjadi 2b / φ.    

                                                .
D. Parameter Fisik Mempengaruhi Plat Heat Exchanger

Enam parameter yang paling penting adalah sebagai berikut:                     .                                      
• Jumlah panas yang akan ditransfer (beban panas).                            .                                        
• Inlet dan outlet suhu di sisi primer dan sekunder.                           .                                   
• Penurunan tekanan maksimum pada sisi primer dan sekunder.                        .                        
• Suhu operasi maksimum.                                                               .
• Tekanan operasi maksimum.                                                    .
• Laju aliran di sisi primer dan sekunder.                                  .
Program Suhu: Ini berarti suhu inlet dan outlet dari kedua media dalam penukar panas.
Panas beban: Mengabaikan kerugian panas ke atmosfer, yang dapat diabaikan, panas hilang (beban panas) dengan satu sisi. Sebuah pelat heat exchanger adalah sama dengan panas yang diperoleh dari yang lain. Beban panas (P) dinyatakan dalam kW atau kkal / jam. Logaritmik Berarti Perbedaan Suhu: Logaritmic Mean Temperature Different (LMTD) adalah kekuatan pendorong yang efektif dalam penukar panas. Panjang Thermal: panjang Thermal (θ) adalah hubungan antara perbedaan suhu dt di satu sisi dan LMTD.                                            .
 E. Heat Transfer Analysis Heat Load, P:

p = mc _p dt and

P = h = A = LMTD

Where,

P = beban panas [kW]

m = laju aliran massa [kg/s] c_p = specific heat [kJ/kg °C]

dt = perbedaan temperatur antara inlet and outlet pada satu sisi [°C]

h = koefisien heat transfer [W/m² °C] A = luas heat transfer  [m²]

LMTD = berarti perbedaan log temperature

Panjang panas [θ]:

q = ^dt LMTD

Logarithmic Mean Temperature Difference [LMTD]:

_{LMTD =} ^DT1 ^{- DT}2 ln(DT₁ / DT₂ )

Disini, DT₁  = T₁  - T₄ , DT₂  = T₂  - T₃

Dimana, T₁ = Temperature inlet – hot side T₂ = Temperature outlet – hot side T₃ = Temperature inlet – cold side T₄ = Temperature outlet – cold side

Total Overall Heat Transfer Coefficient [U]:

1	=	1	+	1	+	Dx	+ Rf
U		hhs		hcs		k

Dimana,

h_hs=koefisien heat transfer  diantara hot medium dan pada permukaan heat transfer  [W/m² °C]

h_cs = koefisien heat transfer pada permukaan heat transfer dan  cold medium[W/m² °C]

Δx = ketebalan permukaan  heat transfer  [m] R_f = The fouling factor [m² °C/W]

k = konduktifitas  thermal dari  material separating the medias [W/m °C]

korelasi Heat Transfer: korelasi heat transfer untuk sebuah  aliran fluida yang melewati permukaan solid adalah expressed in a dimensionless dinyatakan dengan:

Nu = Nu(Re, Pr) Dimana,

Nu=Bilangan  Nusselt Re=Bilangan Reynolds  Pr =Bilangan Prandtl

Untuk aliran laminar , kita espektasikan bilangan Nusselt  Nu tetap tetapi untuk aliran turbulent dinyatakan dengan:

Nu = C₁ Re^a Pr^b

Dimana,C₁, α & β  tetap.

III. LATERATURE SURVEY                                      /
        

Focke W. W. et al. [1] menetapkan bahwa sudut kemiringan antara lipatan plat dan arah aliran keseluruhan adalah parameter utama dalam kinerja hidrolik thermo pelat penukar panas. Transfer rate yang diamati maksimum pada sudut sekitar 80 ° dijelaskan dari pola aliran yang diamati. Pada sudut yang lebih tinggi pola aliran menjadi kurang efektif untuk transfer, khususnya diamati pada 90 ° ditandai aliran pemisahan.

Mehrabian MA dan Pouter R. [2] mempelajari karakteristik hidrodinamika dan karaktristik termal  aliran antara dua plat identik yaitu APV SR3 dan efek dari sudut kerut pada kinerja ketika jarak plat adalah tetap. Perhitungan CFD menunjukkan bahwa sudut kemiringan antara lipatan plat dan arah aliran keseluruhan sebagai parameter utama dalam kinerja hidrolik thermo pelat penukar panas.

Metwally HM dan Mbanglik RM [3] mempertmbangkan periode Laminar secara berkala dengan memperkuat gaya konveksi pada saluran plat bergelombang sinusoidal dengan temperatur dinding seragam dan fase tunggal arus properti konstan. Medan aliran sangat dipengaruhi oleh γ dan Re, dan ini akan menampilkan dua cara yang berbeda: Re rendah atau aliran laminar γ dan pusaran-aliran Re tinggi atau γ.

Gradeck M. et al. [4] melakukan eksperimen untuk mempelajari efek dari kondisi hidrodinamik pada peningkatan perpindahan panas untuk aliran satu fasa. Percobaan ini telah dilakukan untuk berbagai angka Reynolds, [0 <Re <7500] untuk mendapatkan cara yang berbeda dari laminar menjadi turbulen stabil. Akhirnya mereka telah menunjukkan hubungan yang antara kecepatan gradien dinding dan jumlah Nusselt. Penelitian lebih lanjut akan dilakukan pada dua fase dan aliran mendidih.

Bobbili Prabhakara Rao et al. [5] melakukan penelitian eksperimental untuk menemukan aliran dan perbedaan tekanan yang melewati pelabuhan ke saluran plat heat exchanger untuk kisaran bilangan Reynolds 1000-17000. Dalam studi mereka, plat sudut kerut rendah telah digunakan untuk jumlah yang berbeda dari saluran, yaitu, 20 dan 80. Air telah digunakan sebagai fluida kerja(fluid working) untuk cairan panas dan
cairan dingin.       

Longo dan Gasparella [6] melakukan percobaan menggunakan air sebagai fluida kerja(fluid working) dalam jenis herringbone pelat heat exchanger dengan sudut chevron 65˚ dan dikembangkan bilangan Nusselt korelasi. Mereka menggunakan teknik modifikasi Wilson dan variabel efek properti cairan dimasukkan.

Garcı'a Cascales J. R. et al. [7] Menitik beratkan  pada studi perpindahan panas pada plat heat exchanger bekerja dengan R-22 dan R-290, membandingkan korelasi yang berbeda untuk evaluasi koefisien perpindahan panas.

NAPHON Paisarn [8] menyajikan  pengaruh parameter yang relevan pada karakteristik perpindahan panas dan penurunan tekanan .                            .              

Pelat bergelombang yang berbeda sudut 20 °, 40 ° dan 60 ° dengan ketinggian saluran 12,5 mm untuk fluks panas dan bilangan Reynolds dalam kisaran 0,5-1,2 kW / m2 dan 500-1400 diuji. Karena adanya zona resirkulasi, permukaan bergelombang memiliki dampak yang signifikan terhadap peningkatan perpindahan panas dan penurunan tekanan.

Menggunakan teorema Buckingham Pi, Lin J.H. et al. [9] Mengambil korelasi dimensi untuk menggambarkan kinerja perpindahan panas dari saluran bergelombang dalam pelat heat exchanger. Data eksperimen diganti menjadi korelasi ini untuk mengidentifikasi karakteristik aliran dan parameter saluran geometri dengan pengaruh paling signifikan terhadap kinerja perpindahan panas.

Zhi-jian Luan et al. [10] Merancang tipe baru pelat heat exchanger(penukar panas) bergelombang dan dilakukan simulasi eksperimental dan numerik untuk mengamati kinerja perpindahan panas akibat resistensi aliran cairan yang bekerja di atasnya.

Warnakulasuriya dan Worek [11] Melakukan eksperimen perpindahan panas dan penurunan tekanan dari viskos larutan garam dalam pelat penukar panas komersial. Secara keseluruhan koefisien perpindahan panas dan bilangan Nusselt dan bilangan Reynolds meningkat sedangkan faktor gesekan berkurang. Berdasarkan data eksperimen, korelasi untuk jumlah Nusselt dan faktor gesekan yang diperbolehkan.

Tsai Ying-Chi et al. [12] meneliti karakteristik hidrodinamika dan distribusi aliran dalam dua saluran lintas bergelombang pada pelat penukar panas. Kecepatan, tekanan dan aliran distribusi cairan antara dua saluran plat penukar panas dengan karakteristik aliran lokal di sekitar titik kontak telah diusulkan.

Dovic' D. et al. [13] meneliti karakteristik aliran di chevron pelat penukar panas melalui visualisasi saluran dengan β = 28dan β = 61˚. Mathematika Model ini kemudian dikembangkan dengan tujuan menurunkan korelasi perkiraan f dan Nu untuk aliran di saluran geometri [β dan b / l]

Durmus Aydın et al. [14] mempelajari efek geometri permukaan tiga heat exchanger yang berbeda jenis yang disebut sebagai PHEflat [Flat plate heat exchanger], PHE corrugated [pelat bergelombang penukar panas] dan asteriks PHE [penukar panas pelat Asterisk] pada perpindahan panas, faktor gesekan dan energi mengalami kerugian. Percobaan dilakukan untuk kondisi aliran laminar dengan single pass secara paralel dan aliran counter flow memiliki bilangan Reynolds dan bilangan Prandtl di kisaran 50 ≤ Re ≤ 1000 dan 3 ≤ Pr ≤ 7, masing-masing.

Khan T. S. et al. [15] melakukan eksperimen untuk aliran satu fasa [air-to-air] konfigurasi dalam pelat penukar panas komersial untuk simetris 30˚ / 30˚, 60˚ / 60˚, 30˚ dan / 60˚ sudut chevron pelat memiliki bilangan Reynold mulai 500-2500 dan bilangan Prandtl 3,5-6,5. Berdasarkan data eksperimen, korelasi untuk memperkirakan jumlah Nusselt sebagai fungsi dari bilangan Reynolds, jumlah Prandtl dan sudut chevron.

Gherasim Iulian et al. [16] Melakukan penyelidikan eksperimental bidang hidrodinamika dan termal di dua channel chevron-jenis pelat penukar panas untuk kondisi laminar dan turbulen. Faktor gesekan untuk bilangan Reynolds hingga 850 dan nomor Nusselt untuk saluran panas untuk sejumlah Reynolds sampai 1500.

IV. KESIMPULAN                                             .
Percobaan yang dilakukan yaitu untuk menyelidiki karakteristik perpindahan panas dari pelat penukar panas komersial dengan sudut chevron yang berbeda dan parameter geometris lainnya dalam kondisi aliran turbulen. Bilangan Reynolds bervariasi dari sekitar 500-2500. Basis pada data eksperimental, disederhanakan Nusselt angka korelasi menggabungkan efek dari bilangan Reynolds, jumlah Prandtl, variasi viskositas dan sudut chevron.

IV. SCOPE MASA DEPAN                                                                  .
Berbagai jenis plat juga akan diuji dan diselidiki dengan menggunakan set-up. Berdasarkan hasil percobaan yang diperoleh dari set-up dan komputasi analisis dinamika fluida kasus yang sama, baru dapat ditemukan geometri pelat yang berbeda untuk diuji dan dianalisis. Dengan hasil eksperimen baru, program seleksi juga dapat diperpanjang untuk jenis baru dari geometri pelat.

NOMENCLATURE

D_p     Diameter sisi [m]

β       Sudut Chevron[⁰C]

L_w     Lebar Plat [m]

L_h     Jarak Horizontal kedua sisi [m]

P_c      Corrugation pitch [m]

t        Ketebalan Plat [m]

L_v     Jarak Vertical kedua centers dari  ports [m]

L_h     Jarak Horizontal kedua centers dari ports [m]

b       Kedalaman gelombang atau rata-rata jarak channel[m]

φ              Faktor pembesaran permukaan

A_x     Area aliran Channel[m²]

Dh	Diameter Channel hidrolik [m]
ρ	Massa jenis [kgm-3  or kgdm-3]
Δp	Pressure  [kPa]

γ               Aspek rasio

SUBSCRIPT

h         Hydraulic

hs        Permukaan Panas

cs        Permukaan dingin

REFERENSI

[2]   Focke W.W, Zachariades J., Olivier I. , 1985 ―The effect of the corrugation inclination angle on the thermo hydraulic performance of plate heat exchangers‖, Int. J. Heat Mass Transfer 28 [8], pp

1469–1479.

[9]   Mehrabian M.A , Poulter R., 2000 ―Hydrodynamics and thermal characteristics of corrugated channels: computational approach‖,

Applied Mathematical Modelling 24 ,pp 343-364

[10]           Metwally H.M. , Manglik R.M. ,2004 ―Enhanced heat transfer due to curvature-induce lateral vortices in laminar flows in sinusoidal corrugated-plate channels‖, International Journal of Heat and Mass

Transfer 47, pp 2283–2292

[11]           Gradeck M. , Hoareau B., Lebouche M.,2005 ―Local analysis of heat transfer inside corrugated channel‖, International Journal of Heat and Mass Transfer 48 ,pp1909–1915

[12]           Bobbili Prabhakara Rao , Sunden Bengt , Das Sarit K.,2006 ―An experimental investigation of the port flow maldistribution in small and large plate package heat exchangers‖, Applied Thermal

Engineering 26 ,pp 1919–1926

[13]           Longo G.A., Gasparella A., 2007 ―Refrigerant R134a vaporization heat transfer and pressure drop inside a small brazed plate heat exchanger‖, International Journal of Refrigeration 30 , pp 821–830.

[14]           Garcı´a-Cascales J.R., Vera-Garcı´a F., Corber‘an-Salvador J.M., Gonz‘alvez- Maci‘a J. , 2007 ― Assessment of boiling and condensation heat transfer correlations in the modelling of plate heat exchangers‖, International Journal of Refrigeration 30 ,pp 1029-10.

[15]           Naphon  Paisarn,  2007  ―  Laminar  convective  heat  transfer  and

pressure     drop   in   the     corrugated   channels‖,   International

Communications in Heat and Mass Transfer 34,pp 62–71

[13] Lin J.H. , Huang C.Y., Su C.C., 2007 ―Dimensional analysis for the heat transfer characteristics in the corrugated channels of plate heat exchangers‖, International Communications in Heat and Mass Transfer 34 ,pp 304–312

[14]           Zhi-jian LUAN, Guan-min ZHANG, Mao-cheng TIAN, Ming-xiu

FAN ,2008 ―Flow resistance and heat transfer characteristics of a new-type plate heat exchanger‖, Journal of Hydrodynamics 20 ,pp 524-529

[15] Warnakulasuriya F.S.K, Worek W.M.,2008, ―Heat transfer and pressure drop properties of high viscous solutions in plate heat exchangers‖, International Journal of Heat and Mass Transfer 51 ,pp

52–67.

[16]           Tsai Ying-Chi, Liu Fung-Bao , Shen Po-Tsun, 2009 ―Investigations of the pressure drop and flow distribution in a chevron-type plate heat exchanger, International Communications in Heat and Mass Transfer 36 ,pp 574–578

Judul jurnal  :  Analisa Perpindahan Panas Pada Plat Bergelombang Penukar Panas dari Geometry Plat yang Berbeda: A Review

Oleh             :  Jogi Nikhil G.¹, Assist. Prof. Lawankar Shailendra M.²

            ¹ M.Tech student, ² Assistant Professor, Government College of Engineering, Amravati. Maharashtra, India

Pada jurnal yang tersebut dapat kita ketahui bahwa Pelat dengan jenis atau berbentuk  bergelombang memiliki area permukaan perpindahan panas yang lebih luas dan dapat meningkatkan tingkat turbulensi karena adanya lipatan. Baru-baru ini, pelat penukar panas biasanya banyak digunakan karena bila dibandingkan dengan jenis lain dari penukar panas seperti shell dan tube tipe dalam proses perpindahan panas karena kekompakan mereka, kemudahan produksi, sensitivitas, perawatan yang mudah setelah set-up dan pendekatan suhu yang efisien. Pada plat biasanya berbentuk gelombang biasanya terbuat dari stainless steel. Stainless steel digunakan dengan beberapa pertimbangan yaitu karena kemampuannya untuk menahan suhu tinggi, kuat, dan tahanan korosi. Aliran yang melaui plat heat exchanger menggambarkan sifat aliran fluida yang melalui pelat Heat Exchanger, yaitu Cairan primer dan sekunder mengalir dalam arah yang berlawanan di kedua sisi plat.

Parameter Geometric yang Mempengaruhi Plat Heat Exchanger yaitu besaran Sudut Chevron, β: Biasanya bervariasi dari 20 ° sampai 65 °. Faktor Pembesaran Permukaan φ dan Kedalaman Kerut atau Berarti Saluran Spacing (chanel spacing), b: b = p-t, perbedaan antara tingkatan lempeng, p dan ketebalan plat, t Daerah Aliran Channel.

Dari jurnal tersebut dapat kita ketahui bahwa ada 6 (enam) parameter fisik yang mempengaruhi perpindahan kalor yaitu :

•Jumlah panas yang akan ditransfer (beban panas).                            .                                       
•Inlet dan outlet suhu di sisi primer dan sekunder.                           .                                  
•Penurunan tekanan maksimum pada sisi primer dan sekunder.                      .                        
•Suhu operasi maksimum.                                                               .
•Tekanan operasi maksimum.                                                    .
• Laju aliran di sisi primer dan sekunder.   

Dari percobaan yang dilakukan pada jurnal tersebut dapat diketahui bahwa percobaan dilakukan untuk yaitu untuk menyelidiki karakteristik perpindahan panas dari pelat penukar panas komersial dengan sudut chevron yang berbeda dan parameter geometris lainnya dalam kondisi aliran turbulen. Bilangan Reynolds bervariasi dari sekitar 500-2500. Basis pada data eksperimental, disederhanakan korelasi bilangan Nusselt akan menggabungkan efek dari bilangan Reynolds, jumlah Prandtl, variasi viskositas dan sudut chevron.